U.S. Department of Energy

1000 Independence Avenue, S.W.

Washington, D.C. 20585-0121

FY 2002

Progress Report for Fuels for Advanced Compression

Ignition Direct Injection (CIDI) Engines 

Energy Efficiency and Renewable Energy

Office of FreedomCAR and Vehicle Technologies

Approved by Stephen Goguen

November 2002

Fuels for Advanced CIDI Engines FY 2002 Progress Report

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CONTENTS

CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

INDEX OF PRIMARY CONTACTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

II. FUEL/LUBRICANT EFFECTS TESTING ON ENGINE PERFORMANCE . . . . . . . . . 13

A. Oil Consumption Contribution to CIDI PM Emissions during Transient Operation . . . . . . . . . . . . . . . . . . . .13

III. FUEL & LUBRICANT EFFECTS ON EMISSION CONTROL SYSTEM 

PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

A. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Passenger Car Project) . . . . . . . . . . . . . . . . . . .16

B. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Pick-up/SUV Project) . . . . . . . . . . . . . . . . . . .20

C. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Heavy-Duty Project) . . . . . . . . . . . . . . . . . . . .24

D. Lubricant Property Impact on CIDI Emission Control System Durability . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

E. Demonstration of Potential for Selective Catalytic Reduction and Diesel Particulate Filters . . . . . . . . . . . . .32

F. Urea SCR System Evaluation with Emphasis on Unregulated Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

G. The Impact of Oxidation Catalysts on Diesel Engine Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

IV. VEHICLE TEST AND EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

A. The Emissions Impacts of Various Fuels on a CIDI Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

B. EC-Diesel Technology Validation Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

V. SUPPORTING RESEARCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

A. Investigation of the Combustion and Soot-Formation Characteristics of Oxygenated Diesel Fuels . . . . . . . .50

B. Chemical Characterization of Toxicologically Relevant Compounds from Diesel Emissions: 

A Project of the Fuels/Particulate Matter Initiative; Phase I & II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

C. Ultra-low Sulfur Reduction Emission Control Device/Development of an On-board Fuel Sulfur Trap . . . . .62

D. C1 Chemistry for Production of Clean Liquid Transportation Fuels and Hydrogen . . . . . . . . . . . . . . . . . . . .64

VI. MODELING/DATA ANALYSIS/ASSESSMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

A. The Impact of Oxygenated Blending Compounds on PM and NOx Formation of Diesel Fuel Blends . . . . . .68

B. System Emissions Reduction Analysis for Automobiles, Light Trucks, and Heavy-Duty Engines . . . . . . . . .72

C. Fuel Property Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

D. Isotopic Tracing of Fuel Components in Emissions from Diesel Engines Using Accelerator Mass 

Spectrometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82

E. Performance and Properties of Renewable Diesel Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

ACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Fuels for Advanced CIDI Engines FY 2002 Progress Report

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Fuels for Advanced CIDI Engines FY 2002 Progress Report

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INDEX OF PRIMARY CONTACTS

A

Alleman, Teresa . . . . . . . . . . . . . . . . . . . . . . . . .46, 78

B

Berkey, Rick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Buchholz, Bruce A. . . . . . . . . . . . . . . . . . . . . . . . . . .82

F

Frame, Edwin A. . . . . . . . . . . . . . . . . . . . . . . . . .13, 43

H

Huffman, Gerald P. . . . . . . . . . . . . . . . . . . . . . . . . . .64

M

McCormick, Robert . . . . . . . . . . . . . . . . . . . . . . . . .87

McGill, Ralph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Mueller, Chuck . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

R

Rohrbach, Ron . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

S

Storey, John . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

T

Thornton, Matthew J. . . . . . . . . . . . . . . .16, 20, 40, 72

W

Westbrook, Charles K. . . . . . . . . . . . . . . . . . . . . . . .68

Whitacre, Shawn D. . . . . . . . . . . . . . . . . . . . . . .24, 28

Y

Yost, Douglas M. . . . . . . . . . . . . . . . . . . . . . . . . . . .57 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

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Fuels for Advanced CIDI Engines FY 2002 Progress Report

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I. INTRODUCTION

Enabling Advanced Vehicle Technologies through Development and Utilization of 

Advanced Petroleum-Based and Renewable Fuels

On behalf of the Department of Energy's Office of FreedomCAR and Vehicle 

Technologies (FCVT), we are pleased to introduce the Fiscal Year (FY) 2002 Annual 

Progress Report for the Fuels for Advanced Compression Ignition Direct Injection 

(CIDI) Engines Activity which is part of the Fuels Technologies Program. Together 

with DOE National Laboratories and in partnership with private industry and 

universities across the United States, FCVT engages in high risk R&D that provides 

enabling technology for fuel efficient and environment-friendly vehicles. This 

Activity is currently focused on advanced fuels for the CIDI engine, an advanced 

version of the commonly known diesel engine, which is used in both light- and 

heavy-duty vehicles. 

Since its inception, the Fuels for Advanced CIDI 

Engines Activity has supported the FreedomCAR 

government/industry partnership through its technology 

research projects. The work in advanced petroleum-based 

fuels is conducted through joint programs with the energy 

and automotive industries. Advanced petroleum-based 

fuels will also be necessary for the 21st Century Truck Initiative that proposes to 

triple medium-duty truck fuel economy and double heavy-duty truck fuel economy 

on a ton-mile per gallon basis to meet its goals. In FY 2002, the focus of our 

research activities was on developing and testing selected advanced fuels in 

combination with near-term emission control technologies in CIDI engines. The 

Fuels for Advanced CIDI Engines Activity works closely with the Combustion and 

Emission Control R&D Program for Advanced CIDI Engines to assure that the 

advanced fuels work facilitates development of emission control technologies that 

will maintain the high fuel efficiency of CIDI engines while meeting future emission 

standards.

This report highlights progress achieved during FY 2002 and comprises 18 

summaries of industry and National Laboratory projects that were conducted. It 

provides an overview of the exciting work being conducted to tackle the tough 

technical challenges associated with developing clean-burning fuels that will enable 

meeting the performance goals of the Emission Control R&D Program for Advanced 

CIDI Engines. The summaries cover the effects of fuels on CIDI engine emissions; 

the effects of lubricants on engine emissions; the effects of fuels and consumed 

lubricants on exhaust emission control devices; and the health and safety, materials 

compatibility, and economics of advanced petroleum-based fuels. A brief snapshot 

of FY 2002 accomplishments and new directions for FY 2003 is captured on the 

following pages. We are encouraged by the technical progress realized in FY 2002 

and look forward to making further advancements in FY 2003.

Advanced petroleum-based fuels are a critical enabler to allow the high fuel 

economy of diesel-powered vehicles to be maintained while meeting future 

Stephen Goguen

Team Leader

Fuels Technologies

Kevin Stork

Fuels Technologies

Development Manager

John Garbak

Fuels Technologies

Development Manager
Fuels for Advanced CIDI Engines FY 2002 Progress Report

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emission standards. Through this research, the Fuels for Advanced CIDI Engines Activity will identify the 

most suitable fuels for the advanced CIDI engines that power these vehicles. Sulfur content is a very important 

issue for the Fuels for Advanced CIDI Engines Activity. The most desirable emission control devices for 

nitrogen oxides (NOx) are deactivated by sulfur in currently available fuels. Results from the Fuels for 

Advanced CIDI Engines Activity were a primary source of information used by the U.S. Environmental 

Protection Agency (EPA) to establish new diesel fuel sulfur content standards (i.e., 15 ppm maximum) 

beginning in 2006. 

On July 30, 2001, EPA Administrator Christine Whitman announced 

that EPA would request an independent review of the 2007 heavy-duty 

diesel engine emissions standards and the diesel fuel sulfur content 

standard to provide "advice to the EPA on technology issues associated 

with the introduction of technology to reduce engine exhaust emissions 

and technology to lower the sulfur level of highway diesel fuel in 

accordance with the dates incorporated in the highway diesel program 

promulgated in 2001." The Clean Diesel Independent Review Panel was 

thus created to carry out this review. The specific objectives of the 

panel's charter were to assess the progress of:

• manufacturers of diesel engines and emission control systems in 

developing technology to reduce engine exhaust pollutants, and; 

• the fuels industry in developing and demonstrating technologies to 

effectively lower the sulfur level of highway diesel fuel. 

The panel was composed of leading experts from the public health 

community, petroleum refiners, fuel distributors and marketers, engine 

manufacturers, emission control systems manufacturers, and state governments. In their final report, the Panel 

found that NOx adsorbers and catalyzed particulate filter systems are the two leading emission control 

technologies for diesel engines. They also identified that improving the durability of the NOx adsorber, 

especially as it relates to desulfation (removing accumulated sulfur), is the most significant fundamental 

challenge that is being addressed currently. These findings directly support the research priorities of the Fuels 

for Advanced CIDI Engines Activity. 

A major component of the Fuels for Advanced CIDI 

Engines Activity is the Advanced Petroleum-Based Fuels - 

Diesel Emission Control project (APBF-DEC). The APBFDEC is an industry/government project to identify and 

evaluate: (1) the optimal combinations of low-sulfur diesel 

fuels, lubricants, diesel engines, and emission control 

systems to achieve ultra-low NOx and particulate matter 

(PM) emissions for the 2001 to 2010 time period; and (2) 

properties of fuels and vehicle systems that could lead to 

even lower emissions beyond 2010. The activities being 

conducted under the APBF-DEC project include both lightduty and heavy-duty CIDI engines. A systems approach is being used, i.e., simultaneously investigating fuels, 

lubricants, engines, and emissions control systems. A government/industry steering committee and working 

groups are guiding the APBF-DEC project.

The co-operative projects being conducted with the Ad-Hoc Auto/Energy Working Group comprise 

another important component of the Fuels for Advanced CIDI Engines Activity. Phase I of the Ad-Hoc 

program looked at engine-out emissions of a diesel fuel with dimethoxy methane, an oxygenated diesel fuel 

APBF-DEC Participants
Fuels for Advanced CIDI Engines FY 2002 Progress Report

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additive. The results from this study showed that this oxygenated fuel additive significantly lowered PM and 

poly-aromatic hydrocarbon (PAH) emissions compared to the base diesel fuel, and its emissions were 

essentially equivalent to a Fisher-Tropsch fuel. In Phase II, a new set of fuels will be evaluated, including 

different oxygenates blended in refinery produced low-sulfur fuels. The goal of Phase II is to determine the 

impact these fuels have on the physical and chemical characterization of PM after an oxidation catalyst and a 

diesel particulate filter.

SIGNIFICANT FY 2002 ACCOMPLISHMENTS

In FY 2002, much effort continued on the determination of the effects of fuel sulfur content on CIDI NOx

and PM emission control devices. From this work, preliminary findings indicate that NOx emission control 

devices currently do not have sufficient durability to last the full useful life of the vehicle due to sulfur 

contamination from the combined contributions of 15 ppm sulfur fuel and consumed lubricating oil. Future 

work will focus on quantifying the effect of sulfur (from the fuel and lubricating oil) on emission control 

device durability, and the need for sulfur traps and development of desulfurization strategies to attain full 

useful life operation. 

Southwest Research Institute showed that oxygenates can improve the EGR tolerance of CIDI engines 

resulting in significant NOx and PM emission reductions with potential to meet "fuel reformulation" targets. 

Environmental assessments of two of the most promising diesel fuel oxygenates, dibutyl maleate and 

tripropylene glycol monomethyl ether, were completed by Lawrence Livermore National Laboratory (LLNL). 

In tests using these same two oxygenates, Sandia National Laboratories (SNL) found through laser imaging 

that these oxygenates also affect the injected fuel spray patterns with further beneficial effects on PM 

emissions. LLNL made improvements in their new measurement technique to determine the origin of PM 

from CIDI engines, from the components of both the fuel and lubricating oil. Another highlight was the data 

collected by NREL showing that ultra-low sulfur diesel fuel and catalyzed PM traps can reduce HC, CO, and 

PM by 91 to 99%. 

In July 2002, the National Renewable Energy Laboratory (NREL) established the Renewable Fuels and 

Lubricants (ReFUEL) Research Laboratory, a high-altitude facility for testing alternative and advanced fuels 

and heavy-duty engines and vehicles. ReFUEL is the first laboratory in the United States dedicated to 

researching and developing renewable and synthetic fuels and lubricants for heavy-duty transportation 

applications. It's also the only laboratory to evaluate the effects of operating heavy-duty vehicles at high 

altitude. The laboratory houses the following specialized testing and measurement equipment: 

• Chassis dynamometer for developing advanced trucks and buses 

• Engine test cell for fuels R&D 

• Emissions analysis lab for measuring and understanding emissions. 

The ReFUEL Research Laboratory will be used to support various "working group" projects, which were 

developed in response to the needs outlined by groups of government and industry personnel:

• Advanced Petroleum-Based Fuels Project - Identifying optimal combinations of fuels, lubricants, diesel 

engines, and emission control systems for reducing emissions.

• EC-Diesel Technology Validation Project - Evaluating an ultra-low sulfur fuel and particulate matter aftertreatment.

• Fischer-Tropsch Synthetic Fuel Demonstration - Investigating the characteristics of Fischer-Tropsch 

synthetic diesel fuel.

• Next Generation Natural Gas Vehicle Project - Working with industry to develop commercially viable 

medium- and heavy-duty natural gas vehicles. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

4

The following brief summaries list the highlights of research and testing conducted in the Fuels for 

Advanced CIDI Engines Activity during FY 2002.

APBF-DEC Project Progress

APBF-DEC currently directs five individual projects: Effects of Lubricant Composition on Emissions; 

Effects of Fuel Composition on Selective Catalytic Reduction (SCR) and Diesel Particulate Filters (DPF) 

Systems; and the Effects of Fuel Composition on NOx Adsorber/DPF Systems (three separate projects). 

The APBF-DEC projects are timely because of the stricter emissions standards mandated by EPA. 

Between 2004 and 2009, lower emissions standards will be phased in for passenger cars and light-duty trucks. 

For diesel-powered vehicles to comply with these standards, catalytic emission control systems will be 

required. EPA has also set new emission standards for heavy-duty engines, which will go into effect in 2007, 

and a standard for the sulfur content in highway diesel fuel slated to go into effect in 2006. These standards 

(for emissions of both PM and NOx) will require catalytic emission control systems on heavy-duty vehicles.

The following provides updates of progress for each of the APBF-DEC projects over the past year.

Effects of Lubricant Composition on Emissions

The Diesel Emission Control - Sulfur Effects project (http://www.ott.doe.gov/decse/) quantified the impact 

of diesel fuel sulfur on the performance and short-term durability of diesel emission control devices. The acute 

sensitivity of certain of these devices highlighted the need to study another source of sulfur and other potential 

poisons - specifically the diesel lubricating oil. 

To address this concern, a research project to 

study lubricant formulation (basestocks and 

additives) effects on diesel emission control 

systems is entering its second year. It is 

anticipated that the results of this study will be 

critical in defining the needs of future lubricant 

formulations for both light-duty and heavyduty diesel engines. An International T444E 

(7.3L, V8) has been installed in an emissions 

test cell and has been upfit with exhaust gas 

recirculation (EGR) and closed crankcase 

ventilation (CCV) hardware similar to future 

base engine designs. During the past year, test 

lubricants ranging in sulfur content between 0 

and 6500 parts per million (ppm) and ash 

between 0% and 1.85% have been prepared in four basestocks - one each from the four major base oil 

classifications (Group I-IV) as defined by the American Petroleum Institute (API). All Phase I testing, 

including 12 additives and four basestocks, has been completed. In the coming year, the influence of the 

lubricant derived emission components on catalyst durability will be examined, and a rapid aging protocol to 

accelerate lubricant effects testing will be developed and utilized to determine if consumed diesel engine oil 

impacts catalyst life.

Effects of Fuel Composition on SCR/DPF Systems

The overall objective of this project is to demonstrate the low-emissions performance of advanced diesel 

engines operating on advanced fuels, and equipped with low-pressure-loop EGR plus urea SCR and DPF. 

During the past year, a Caterpillar C-12 engine was installed in an emissions test cell and tested in its asSO2 Emissions for the Various Oils Tested
Fuels for Advanced CIDI Engines FY 2002 Progress Report

5

received configuration with D2 diesel fuel 

containing 350 ppm sulfur. Emissions 

results for the baseline over the U.S. 

heavy-duty transient cycle were ~ 3.55 g/

hp-hr NOx and ~ 0.065 g/hp-hr PM. 

Results over the steady-state European 

OICA cycle were 4.82 g/hp-hr NOx and 

0.031 g/hp-hr PM. The engine was fitted 

with a low-pressure-loop cooled EGR 

system provided by STT-Emtech in 

Sweden and a diesel particulate filter (part 

of System A) provided by the 

Manufacturers of Emissions Control 

Association (MECA), and the systems 

were optimized for low engine-out NOx. 

Engine-out NOx over the transient cycle with the EGR system using 3-ppm sulfur fuel was reduced to 1.5 g/hphr (58%). Over the steady-state OICA cycle, NOx emissions were reduced to 2.32 g/hp-hr (52%). Particulate 

emissions for both tests remained below 0.01 g/bhp-hr. The urea SCR catalyst of System A was added to the 

emission control system along with urea injection systems provided by Robert Bosch, and the calibration of the 

SCR system for NOx reductions was engineered. Results on the steady-state OICA test showed tailpipe NOx

reduced to only 0.17 g/hp-hr (96%). The calibration is being optimized at this time for testing over the 

transient cycle. Then, a matrix of emission tests with the different fuels will be carried out before the system is 

installed on one of the durability engines for the beginning of the 6,000-hour durability test.

Effects of Fuel Composition on NOx Adsorber/DPF Systems

The overall objective of these projects is to demonstrate the potential of NOx adsorber technology in 

combination with diesel particulate filters, advanced fuels, and advanced engine controls to achieve stringent 

emission levels while maintaining high fuel economy in light-duty cars and trucks and heavy-duty engines. 

The goal for the light-duty projects is to achieve stringent Tier 2 Bin 5 light-duty emission standards with limits 

of 0.07 g/mi NOx and 0.01 g/mi PM. The goal for the heavy-duty engine is to achieve the stringent 2007 

standards of 0.2 g/bhp-hr NOx and 0.01 g/bhp-hr PM. In addition, these projects intend to determine the 

necessary fuel sulfur level and other fuel properties that will enable these systems. The fuel sulfur levels tested 

will be representative of those required to be available beginning June 2006 (<15 ppm S).

• Passenger Car Engine/Vehicle

A model year 2001 Audi A4 Avant with a 1.9 liter TDI 

engine (100 KW at 4,000 rpm) with a Bosch common rail second 

generation fuel injection system, integrated EGR and a Garett 

GT 17 V turbine was acquired as the test vehicle for this project. 

Two additional engines were acquired and installed in emissions 

test cells. The emission control system (ECS) architecture was 

designed, and exhaust system modifications were completed. 

An integrated external electronic controller was installed to 

control post injection and lean and rich cycling conditions 

necessary for catalyst regeneration. Rapid warm-up procedures, 

other thermal management approaches, and protocols for 

sampling and analysis of unregulated toxic emissions were 

developed. ECS system regeneration and desulfurization 

Progression of NOx Emission Reductions

Schematic of Passenger Car Emission Control 

System
Fuels for Advanced CIDI Engines FY 2002 Progress Report

6

strategies were devised. A limited amount of baseline and engine-out data has been collected. Aging and 

evaluations testing will generate a significant body of data in FY 2003.

• Light Truck Engine/Vehicle

A model year 2002 Chevrolet 2500 Series Silverado 

with a 6.6 liter Duramax engine (300 HP at 3100 rpm) 

with a Bosch common rail fuel injection system, 

integrated exhaust gas recirculation (EGR), charge air 

cooler, and a center mounted turbine was acquired as the 

test vehicle for this project. In order to make the 

objectives of this project possible and limit the reduction 

efficiencies required by the aftertreatment devices, 

significant modifications have been made to the test 

engine to lower engine-out emissions. These include 

installation of low pressure EGR, a turbo by-pass system, 

and engine calibration changes (for lower engine-out NOx

and more favorable exhaust temperature profiles). In 

addition, secondary injection and dual wall insulated 

exhaust components will be used to retain heat for the 

ECS. A limited amount of baseline and engine-out data 

has been collected. Aging and evaluations testing will generate a significant body of data in FY 2003.

• Heavy-Duty Engine

A 15L Cummins ISX 500 hp inline, 6-cylinder heavyduty diesel engine has been installed for testing. This engine 

has dual overhead camshafts and is equipped with integrated 

EGR and a variable geometry turbocharger (VGT) and is 

calibrated to meet the 2004 heavy-duty (HD) emission 

standards (2.5 g/bhp-hr NOx, 0.1 g/bhp-hr PM). 

Modifications made for testing include: installation of 

secondary in-cylinder fuel injectors and engine calibration 

changes (for lower engine-out NOx and more favorable 

exhaust temperature profiles). Preliminary results indicate 

that the NOx adsorber catalyst can reduce NOx emissions by 

85% and, at peak efficiency, by up to 98%. Early results also 

show NOx emissions can be reduced to 0.10-0.20 g/bhp-hr, 

nearing the 2007 targets. However, HC emissions were high 

(1.4 g/bhp-hr), and the associated fuel economy penalty is 

greater than desired (10%). Optimization of the rich 

regeneration strategy and addition of a downstream diesel 

oxidation catalyst (DOC) is required to minimize 

hydrocarbon (HC) slip. The back pressure associated with 

the emission control devices has prohibited operating at high load conditions. Cycling the engine from lean to 

rich places additional demands on the engine, turbocharger, and EGR system, so durability effects on the 

engine may need to be evaluated further. Aging and evaluations testing will generate a significant body of data 

in FY 2003.

6.6 liter Duramax Engine

Single and Dual Leg Emission Control Systems 

are Being Tested
Fuels for Advanced CIDI Engines FY 2002 Progress Report

7

LLNL Refines Technique to Trace the Origin of Emissions from Fuel Composition

Regulatory pressure to significantly reduce the 

particulate emissions from diesel engines is driving 

research into understanding mechanisms of soot 

formation. If mechanisms are understood, then 

combustion modeling can be used to evaluate possible 

changes in fuel formulation and suggest possible fuel 

components that can improve combustion and reduce 

PM emissions. The combustion paradigm assumes 

that large molecules break down into small 

components and then build up again during soot 

formation. Lawrence Livermore National Laboratory 

(LLNL) has applied accelerator mass spectrometry 

(AMS) to fuel combustion in engines. AMS allows 

labeling specific carbon atoms in fuel components, 

including oxygenates, tracing the carbon atoms, and 

directly measuring how fuel molecular structure 

affects emissions. Volatile and non-volatile organic 

fractions (VOF, NVOF) in the PM can be further 

separated. The effectiveness of exhaust stream catalysts to oxidize products from tracer fuel components can 

be monitored through AMS measurement of carbon in PM. The data collected during the past year provide 

direct validation of chemical kinetic models. Using this information, the PM-producing tendencies of fuels can 

be predicted without doing extensive and expensive engine testing. It will also provide information on the 

types of fuel structures that best reduce formation of PM. 

ORNL Explores Unregulated Emissions from Urea SCR Emission Control Systems

Urea selective catalytic reduction (SCR) has 

emerged as a promising technology for the reduction of 

NOx from CIDI engines. Several groups have 

demonstrated emissions levels at or near the EPA 2007 

HD standards as well as Tier 2 levels for light-duty 

vehicles. The technology uses a urea solution injected 

into the exhaust as a source of ammonia, which then 

reacts with NOx on the catalyst to reduce NOx to N2. 

In an ideal case, the urea dissociates completely in the 

exhaust to ammonia and CO2. However, many other 

urea decomposition products are possible. 

These and other unregulated emissions, such as 

NH3 and N2O, are important to characterize both for 

potential health effects issues as well as an indicator of catalyst system performance. Unregulated emissions 

were collected during this preliminary phase of the research. Impinger samples showed an excess of cyanic 

acid being generated during several of the modes which is believed to be due to excess urea solution being 

injected. While the preliminary results were unusual due to the excess of urea injected, the methods developed 

for unregulated emissions analysis worked very well, and much better success in subsequent experiments with 

a properly functioning urea injection system is anticipated. Further work will focus on testing of two SCR 

formulations and two fuels. Because of the unusual results with excess urea injection, it is planned to study 

Measurements of Total Carbon and the Non-Volatile 

Organic Fraction

NOx Reduction Effectiveness at Two Operating 

Conditions
Fuels for Advanced CIDI Engines FY 2002 Progress Report

8

more mild excursions from normal operation. An important finding from this work will be to define the 

threshold to the excess urea injection above which the unusual chemistry occurs. 

LLNL Studies the Impact of Oxygenated Blending Compounds on PM and NOx Formation of 

Diesel Fuel Blends 

Chemical kinetic modeling has been developed 

uniquely at Lawrence Livermore National Laboratory 

(LLNL) to investigate combustion of hydrocarbon fuels 

in practical combustion systems such as diesel engines. 

Experimental diesel engine studies have indicated that 

when oxygen is added to diesel fuel, soot production in 

the engine is reduced. The soot reduction appears to be 

largely independent of the way oxygen is incorporated 

into the reactants, whether through entrainment of 

additional air into the reacting gases or direct inclusion 

of oxygen atoms into the diesel fuel molecules. During 

the past year, LLNL examined dibutyl maleate (DBM) 

and tripropylene glycol monomethyl ether (TPGME), 

both of which include significant amounts of oxygen 

imbedded in the primarily hydrocarbon fuel molecule. 

Detailed chemical kinetic reaction mechanisms were 

developed for both of these fuels, and the resulting 

models were used to assess their sooting tendencies. 

The model calculations indicate that the distribution of oxygen atoms within the fuel molecule can have a 

significant influence on the anti-sooting effects of the oxygen atoms. TPGME is an excellent example of such 

a fuel. Ongoing kinetic analyses are examining the implications of these results and may lead to new 

definitions of potentially important diesel fuels for engine combustion.

NREL Tests Heavy-Duty Vehicles after Using EC-Diesel and PM Filters for One Year

ARCO, a BP company, has developed two new 

diesel fuels called Emission Control Diesel (ECD) and 

Emission Control Diesel-1 (ECD-1). Both fuels have 

sulfur content less than 15 ppm. The ECD fuel has an 

aromatics content of 10% and a cetane number of 60. 

The ECD-1 fuel, BP's commercial product, has an 

aromatics content of 22% and a cetane number of 50. 

Catalyzed diesel particle filters have been shown to 

operate more efficiently as diesel fuel sulfur content is 

decreased. Ultra-low sulfur diesel fuels expand the 

filter regeneration temperature window, improving 

particulate matter removal for a wide range of engine 

operating conditions. A one-year technology validation 

project was conducted to evaluate ECD and catalyzed 

diesel particle filters on diesel vehicle fleets in Southern 

California. The fuel's performance, impact on engine 

durability and vehicle performance, and emission 

characteristics were evaluated and compared to conventional California Air Resources Board (CARB) 

specification diesel fuel. Two rounds of emissions testing have been completed, showing that the filters are 

Chemical Structure of TPGME and DBM

Emission Reductions Using ECD-1 Fuel and Catalyzed 

PM Filters
Fuels for Advanced CIDI Engines FY 2002 Progress Report

9

effective at removing PM, HC, and CO emissions after twelve months of continuous use. Vehicles operating 

on ECD with the filters did not have a significant fuel economy penalty compared to vehicles operating on 

conventional diesel fuel. The filters were effective at reducing unregulated emissions, such as PM10, PM2.5, 

and light olefins. 

SNL Investigates Combustion Characteristics of Advanced Diesel Fuels 

Blending oxygen-containing compounds ("oxygenates") with diesel 

fuel can lead to reduced soot and NOx emissions, as well as reduced fuel 

consumption. The detailed mechanisms that cause such reductions are 

not well understood. SNL used spatially integrated natural luminosity 

(SINL) as a means to estimate in-cylinder soot concentrations. They 

found that the relative amount of soot produced decreases as the oxygen 

content of the fuel increases. Two promising oxygenated fuels were 

tested, and one oxygenated fuel was found to be more effective at 

reducing soot than the other, even though their oxygen content, 

combustion phasing, adiabatic flame temperature, and engine operating 

conditions were matched. Two possible explanations for the difference 

observed are differences in air entrainment and differences in molecularstructure/chemical characteristics of the fuels. Experiments using 

accelerator mass spectrometry diagnostics are currently underway to test 

this hypothesis and to identify improved oxygenate molecules for PM 

reductions. 

SwRI Explores Toxic Emissions from Advanced CIDI Engines and Fuels

The control of NOx emissions is 

probably the greatest technical challenge in 

meeting future emission regulations for 

diesel engines. In this project, lowering 

engine-out emissions of NOx by increasing 

EGR and retarding timing will likely cause 

an increase in PM emissions. In Phase I of 

this project, it was shown that the use of an 

oxygenated diesel fuel additive will lower 

PM emissions. Use of an oxygenated diesel 

fuel additive thereby can minimize the 

increase in PM emissions that accompany 

the techniques used to decrease NOx

emissions. The overall objective of this 

project is to better understand the effects 

of fuels and emission control devices on 

the exhaust emissions of a subset of 

potentially toxicologically relevant 

compounds from an engine operated to minimize NOx emissions. Testing confirmed that oxygenated diesel 

fuels and Fischer-Tropsch diesel fuels made from natural gas have greater capacity to reduce NOx emissions 

without increasing PM emissions. Investigation of the role of fuels in reducing tailpipe exhaust emissions of 

potentially toxicologically relevant compounds, utilizing a diesel oxidation catalyst and a catalyzed particulate 

filter, will be starting in late FY 2002.

NOx and PM Emissions for the Fuels Tested
Fuels for Advanced CIDI Engines FY 2002 Progress Report

10

The Consortium for Fossil Fuel Science (CFFS) Researches Production of Clean Liquid Transportation Fuels from Natural Gas

The Consortium for Fossil Fuel Science (CFFS) is a research consortium with participants from five 

universities - the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia 

University, and Auburn University. The CFFS universities are collaborating in a research program to develop 

C1 chemistry processes to produce clean transportation fuel from resources such as coal and natural gas, which 

are more plentiful domestically than petroleum. The processes under development will convert feedstocks 

containing one carbon atom per molecular unit into ultra clean liquid transportation fuels (gasoline, diesel, and 

jet fuel) and hydrogen, which many believe will be the transportation fuel of the future. The feedstocks include 

syngas, a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas; 

methane; methanol; carbon dioxide; and carbon monoxide. During the past year, CFFS research has 

discovered that small (~1%) additions of probe molecules with carbon-carbon triple bonds dramatically 

enhance the presence of oxygenated products in Fischer-Tropsch diesel fuel which assist in reducing PM 

emissions. In addition, CFFS has developed Pt/W/ZrO2 catalysts that are very effective at increasing the yield 

of Fischer-Tropsch diesel fuel by converting the waxes that are co-produced. 

Honeywell Initiates Development of an Onboard Fuel Sulfur Trap

The objective of this project is to demonstrate at the pilot scale level proof-of-concept for a fuel 

desulfurization filter that is able to reduce sulfur levels in the fuel to tolerable levels which enable the 

implementation of post-combustion NOx adsorber technology. A sulfur removal device can expedite 

implementation of new emission control systems by reducing the need for diesel fuels to attain ultra low sulfur 

levels. It is anticipated the cost of the proposed sulfur-removal device to the consumer will represent no more 

than a low multiple of the current cost of a standard fuel filter. This project began in April 2002. 

Representative fuel samples have been prepared, and sufficient quantities of these are now in place to begin the 

experimental stage of the project. Analytical procedures have been put in place for measuring total sulfur and 

speciation of the sulfur contaminants.

FUTURE INITIATIVES

Our new initiatives for FY 2003 build upon the progress made in FY 2002 and will focus on those areas 

that industry agrees are major technical barriers.

• Honeywell On-Board Desulfurization Fuel Filter: Honeywell will survey all applicable current and 

proposed approaches to fuel desulfurization and rank those suitable for on-board filtering. Following 

the down-select of potential technologies, laboratory screening of them will be conducted prior to 

prototype development and on-vehicle demonstration. 

• Advanced Petroleum-Based Fuels - Diesel Emissions Control: APBF-DEC projects are anticipated to 

complete the activities described in the following:

Effects of Lubricant Composition on Emissions: It will be determined to what extent lubricant related 

emissions species impact the performance and durability of emissions control devices designed to reduce 

NOx and PM emissions from diesel engines. A protocol for rapidly aging emission control devices and 

determining lubricant effects will be developed. This test protocol will then be utilized to determine if 

lubricant sulfur, ash, and certain metals need to be controlled to meet useful life standards placed on 

emission control systems.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

11

Effects of Fuel Composition on SCR/DPF Systems: Emissions testing using System A will be completed, 

and the emissions tests with the fuels matrix will be carried out. Following that, System A will be moved 

to the durability test cell while work will begin on System B to optimize and calibrate that system for 

minimum emissions.

Effects of Fuel Composition on NOx Adsorber/DPF Systems: All three projects (Passenger Car Engine/

Vehicle, SUV/Pick-Up Engine/Vehicle, and Heavy-Duty Line Haul Engine) are being conducted in parallel 

with similar objectives and project activities. In the coming year, these projects will finish baseline tests 

with 8- and 15-ppm sulfur fuels and a low sulfur refinery fuel (called BP15) to characterize engine-out 

emissions (no catalysts) during transient and steady-state operation. Aging tests on complete catalyst 

systems will be initiated with emissions tests conducted every 50 hours up to 300 hours using 8- and 15-

ppm S fuels and BP15 over the FTP, US06, and HFET cycles for the passenger car and SUV/Pick-Up 

projects and the HD FTP and 13-mode steady-state tests for the heavy-duty project. This will be followed 

by extended catalyst system aging and testing every 100 hours for up to 1500 hours depending on the 

project. A limited amount of testing will also be conducted with 30-ppm S fuel to determine the impact of 

misfueling with a higher sulfur fuel. Study of fuel properties other than sulfur to determine their impact on 

the NOx adsorber/DPF systems will then be initiated and assessed more thoroughly during the second 

phase of the APBF-DEC activity.

• Field testing of ECD-1: Additional results, including polycyclic aromatic hydrocarbons (PAH), nitroPAH (n-PAH), and 1,3-butadiene, from the chemical characterization will be published in FY03. 

• Lube Oil Contribution to PM: Southwest Research Institute will measure the contribution of synthetic 

and mineral-based lubricating oil to PM emissions in combination with advanced fuels relative to a 

base fuel representative of those expected in 2007.

• Sandia National Laboratories: SNL will measure test-fuel lift-off lengths in their optical engine and 

compare to results from the Diesel Combustion Simulation Facility (DCSF). They will also study 

multiple-jet and jet-wall interactions and measure test-fuel soot distributions using a quantitative laserextinction diagnostic. They will continue accelerator mass spectrometry experiments with oxygenates 

and expand the scope to include other fuel constituent molecules. Development of in-cylinder NOx

measurement capabilities to study combined effects of fuels and operating conditions on NOx

evolution will be initiated.

• Effect of Oxidation Catalysts on PM: CRC will conduct emissions tests on catalyst 3 (the one with the 

highest metal loading), and chemical analyses will be completed on the exhaust samples. A final 

report will be prepared.

• Emissions Tests of Advanced Diesel Fuels: Southwest Research Institute will test six advanced fuels 

(oxygenated and water emulsion fuels) in a vehicle with a state-of-the-art CIDI engine. The baseline 

fuel will be representative of diesel fuel properties expected in 2007. The vehicle will be equipped 

with advanced emission control devices such as NOx adsorbers and diesel particulate filters. 

• PM Emission Toxicology: Southwest Research Institute will investigate of the role of fuels in 

reducing tailpipe exhaust emissions of potentially toxicologically relevant compounds, from an 

advanced CIDI engine using a diesel oxidation catalyst and a catalyzed particulate filter.

• Impact of Oxygenates on PM and NOx Formation: LLNL will extend its model capabilities to include 

additional oxygenated blending compounds and increase collaborations with projects outside LLNL 

dealing with diesel fuel issues. 

• Systems Emission Reduction (SER) Analysis: NREL will analyze pathways for reducing emissions 

from the three vehicle platforms and investigate specific applications of analysis tools such as the 

effect of compression ratio, EGR, and aftertreatment devices on efficiency, and fuel formulation 

effects on emissions. A process to validate the model at a systems level will be developed, and 

relevant data from research partners will be identified and collected.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

12

• Fuels Property Database: NREL will continue to populate fuels and emissions databases with lightduty engine and vehicle emissions data. The APBF-DEC projects will be a prime source of data, along 

with other DOE-sponsored research projects. 

• Tracing of Fuel Components in PM Emissions Using Accelerator Mass Spectrometry: LLNL will 

determine the contributions of major fuel components to soot production, including selected 

oxygenates. They will also apply tracing techniques to measure the contribution of aromatics and 

cyclo-alkanes to emission products in diesel engines. Carbon-14 labeled lube oil will be obtained to 

determine the contribution of lube oil to soot and CO2 emissions.

SUMMARY

Advanced petroleum-based fuels enable the use of high efficiency prime movers such as CIDI engines to 

create clean and fuel efficient light-duty and heavy-duty vehicles with the attributes that consumers demand. 

Fuel efficient vehicles with very low emissions are essential to meet the challenges of climate change, energy 

security, and improved air quality. The work being conducted on advanced petroleum-based fuels 

complements the efforts to build advanced engines and fuel cells while recognizing that the engine, fuel, and 

emission control system must work together to achieve the maximum benefits possible. As the new fiscal year 

begins, we look forward to on-going and new cooperative efforts with the auto and energy industries to 

develop new and innovative technologies that will be used to make advanced transportation vehicles that are 

fuel-efficient, clean, and safe.

Stephen Goguen

Team Leader

Fuels Technologies

Office of FreedomCAR and 

Vehicle Technologies

Kevin Stork

Fuels Technologies

Development Manager

Office of FreedomCAR and 

Vehicle Technologies

John Garbak

Fuels Technologies

Development Manager

Office of Hydrogen, Fuel Cells and

Infrastructure Technologies
Fuels for Advanced CIDI Engines FY 2002 Progress Report

13

II. FUEL/LUBRICANT EFFECTS TESTING ON ENGINE 

PERFORMANCE

A. Oil Consumption Contribution to CIDI PM Emissions during Transient 

Operation

Edwin A. Frame (Primary Contact) 

Southwest Research Institute

6220 Culebra Road

San Antonio, TX 78238-5166

(210) 522-2515, fax: (210) 522-3270, e-mail: eframe@swri.edu

DOE Technology Development Manager: John Garbak 

(202) 585-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

A. Fuel Property Effects on Engine Emissions and Efficiency

Tasks

2. Fuel & Lubricant Properties - Engine-Out Emissions

Objective

• Quantify the effect of crankcase lubricant type on exhaust emissions measured during transient tests of 

a light-duty vehicle powered by a state-of-the-art CIDI engine.

Approach

• A European Mercedes C 220 D vehicle (OM611 engine) will be tested for transient exhaust emissions 

following the chassis dynamometer portion of the light-duty Federal Test Procedure (FTP-75) and 

US06 test cycles. Synthetic and mineral-based crankcase lubricants will be tested in combination with 

advanced fuels to determine the effect of lubricant composition on PM and other exhaust emissions. 

Accomplishments

• Testing was delayed pending the availability of a special base fuel that is a refinery produced prototype 

of 2007 U.S. ultra-low-sulfur diesel fuel. The test lubricants have all been obtained and conditioned in 

an OM611 test engine to reduce volatile light ends. Testing is currently in progress.

Introduction

The Phase 1 project, "Impact of Consumed Lube 

Oil on Advanced CIDI Engine Emissions," revealed 

a significant impact of consumed oil on particulate 

matter (PM) under low-power steady-state conditions 

and an insignificant impact over the high-power, FTP 

heavy-duty, transient test cycle. However, the impact 

of consumed oil was not investigated for any lightduty transient test cycle. 

In the previous project, it was determined by the 

direct filter injection gas chromatography (DFI/GC) 

technique that the oil-volatile organic fraction (VOF) 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

14

fraction can be reduced from 27% for a petroleumbased SAE 5W30 oil to 8% for a synthetic-based 

SAE 15W50. This illustrated that a PM reduction of 

approximately 19% is obtainable by changing the 

lubricant. This reduction was observed under steadystate, light-duty conditions when using California Air 

Resources Board (CARB) fuel. The fundamental 

question is whether the impact of consumed oil on 

PM emissions over the light-duty transient cycle will 

be similar to the impact observed over the low-power 

steady-state conditions investigated as part of the 

Phase 1 study. 

Approach

A European Mercedes-Benz C220D vehicle will 

be tested for transient exhaust emissions following 

the light-duty FTP-75 and US06 test cycles. 

Synthetic and mineral-based lubricants will be tested 

in combination with advanced fuels to determine the 

effect of lubricant composition on PM. 

The European Mercedes-Benz C220D is 

equipped with the OM611 engine. This advanced 

four-valve-per-cylinder CIDI engine is turbocharged 

and intercooled, and it includes a high-pressure 

common rail fuel injection system with pilot 

injection, exhaust gas recirculation, and intake port 

cut-off. The vehicle is equipped with a closecoupled oxidation catalyst and "lean NOx" catalyst 

technology. 

All evaluations will be conducted in triplicate 

over the chassis dynamometer portion of the FTP-75 

and the US06 driving cycles.

An ultra-low-sulfur baseline fuel (BP15), 

formulated to be representative of expected U.S. 

diesel fuel in 2007, will be used for the initial 

evaluation of lubricant contribution to PM. The 

following lubricants will be included in the test 

matrix: synthetic SAE 5W30, mineral SAE 5W30, 

synthetic SAE 15W50, and synthetic SAE 0W30. In 

addition, FTP 75 and US06 tests will be conducted 

using the same lubricants and a fuel blend of BP15 

Fuel with an advanced oxygenate (tripropylene 

glycol monomethyl ether-TPGME) blended to 

provide 7% oxygen in the fuel. 

Exhaust constituents will be analyzed as 

specified below:

Figure 1 shows a gas chromatogram of the 

volatile organic fraction (VOF) of PM. The VOF is 

fractionated into unburned oil and other volatile 

material.

Appropriate statistical techniques will be used to 

determine differences between the PM and other 

exhaust emissions for each lubricant and each 

lubricant/fuel combination.

Results

The project was delayed pending the availability 

of the BP15 Fuel. Testing is under way, and some 

preliminary results are discussed as follows. 

Figure 1. Gas Chromatogram of the VOF of PM

Constituent Analysis Method

Total Hydrocarbon Heated Flame Ionization 

Detector

Carbon Monoxide Non-Dispersive Infrared

Analysis

Carbon Dioxide Non-Dispersive Infrared 

Analysis

Oxides of Nitrogen Chemiluminescent Analysis

Particulate Matter Gravimetric

Volatile Organic 

Fraction of PM

Direct Filter Injection Gas 

Chromatography

Oil Fraction of VOF Direct Filter Injection Gas 

Chromatography
Fuels for Advanced CIDI Engines FY 2002 Progress Report

15

Triplicate FTP and US06 tests have been completed 

for the mineral SAE 5W30, the synthetic SAE 

15W50 using BP15 fuel, and the blend of BP15 fuel 

with TPGME. Initial FTP results show a 2.5% fuel 

economy penalty for the SAE 15W50 oil as 

compared to the mineral (baseline) SAE 5W30 oil 

when using BP15 fuel. 

The oxygenated fuel blend had a fuel economy 

penalty of approximately 2-3 miles per gallon for 

most test cycles. Over the FTP cycle, the oxygenated 

fuel reduced particulate matter by approximately 

53%, compared to neat BP15 fuel. This effect was 

observed for both oils tested to date. FTP NOx 

emissions with the oxygenated fuel were increased 

by 16 to 25%. Additional tests are continuing.

Conclusions

The project will be completed early in 2003.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

16

III. FUEL & LUBRICANT EFFECTS ON EMISSION CONTROL 

SYSTEM PERFORMANCE

A. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Passenger Car 

Project)

Matthew J. Thornton (Primary Contact), Wendy Clark

National Renewable Energy Laboratory

1617 Cole Blvd., MS 1633

Golden, CO 80401

(303) 275-4267, fax: (303) 275-4273, e-mail: matthew_thornton@nrel.gov

DOE Technology Development Managers: 

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Peter Devlin: (202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Steve Goguen: (202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Kevin Stork: (202) 586-8306, fax: (202) 586-2476, e-mail: Kevin.Stork@ee.doe.gov

Other Participants: American Petroleum Institute (API), Engine Manufacturers Association (EMA), 

Manufacturers of Emissions Control Association (MECA), U. S. Environmental Protection Agency 

(EPA), Oak Ridge National Laboratory (ORNL), California Air Resources Board (CARB)

Subcontractor: FEV Engine Technology, Auburn Hills, MI 

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects on Exhaust Emission Control System Technology

C. Emission Control System Degradation

D. Sulfur Impacts

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Determine the influence of diesel fuel composition on the ability of NOx adsorber technology, in 

conjunction with diesel particulate filters (DPFs), to achieve stringent emissions levels with minimal 

fuel economy impact. 

• Achieve Tier 2 Bin 5 emission standards of 0.07 g/mi NOx and 0.01 g/mi PM. 

• Determine the necessary fuel sulfur level and other fuel properties that will enable high performance of 

these NOx adsorber/DPF systems.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

17

Approach

A model year 2001 Audi A4 Avant with a 1.9 liter TDI engine (100 KW at 4000 rpm) with a Bosch 

common rail second generation fuel injection system, integrated exhaust gas recirculation (EGR) and a 

Garett GT 17 V turbine will be used as the test vehicle for this project. This vehicle will be equipped with 

appropriately designed emission control devices and the necessary regenerative control hardware and 

electronics to meet the project objectives. This project includes three major tasks:

• Task A involves development of the test platform including setup, integration, and optimization of the 

engine, rapid warm-up testing and thermal management; emission control system (ECS), and 

associated electronic controls; and baseline (engine-out) testing of regulated and unregulated (toxic) 

emissions.

• Task B involves system performance and aging tests using fuels with varying sulfur content (8-, 15-, 

30-ppm S) and periodic evaluations of emissions over the FTP, US06, and HFET during aging tests up 

to 1000 hours of operation. Two single-leg ECS architectures will be developed and tested.

• Task C will investigate fuel properties other than sulfur and determine their impact on the NOx

adsorber/DPF system. This testing will include an ultra-low sulfur (<15-ppm S) refinery fuel and up to 

three additional fuels. No aging tests will be conducted in Task C.

Accomplishments

• Acquired test vehicle and four engines and installed one engine in vehicle and two engines in 

emissions test cells

• Designed ECS architecture and competed exhaust system modifications 

• Integrated an external electronic controller with the base engine electronics to control post injection 

and lean and rich cycling conditions necessary for catalyst regeneration

• Developed rapid warm-up procedures and other thermal management approaches

• Developed protocols for sampling and analysis of unregulated toxic emissions

• Completed initial ECS system regeneration and desulfurization strategies

Future Directions

• Complete the development of catalyst regeneration and desulfurization strategies (Task A)

• Conduct durability testing with fuels of varying sulfur content (Task B)

• Conduct testing of other fuel properties (Task C)

Introduction

The Advanced Petroleum Based Fuels – Diesel 

Emission Control (APBF-DEC) activity is a joint 

government/industry research effort to determine the 

best combinations of low-sulfur diesel fuels, 

lubricants, diesel engines, and emission control 

systems to meet projected emission standards for the 

2002 to 2010 time period. The project leverages the 

participation of several multi-industry working 

groups that direct five individual projects.

This project aims to demonstrate the viability of 

combining NOx adsorber catalysts and DPF 

technologies in combination with clean fuels, 

advanced engines and electronic controls to achieve 

stringent emission levels while maintaining high fuel 

economy. Specifically, this project will identify the 

fuels needed to enable these technologies for use in 

light-duty vehicles. The goal for this platform is to 

meet stringent Tier 2 Bin 5 light-duty emission 

standards with limits of 0.07 g/mi NOx and 0.01 g/mi 

PM.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

18

 Another critical focus of this project is the 

characterization of currently unregulated, but 

potentially toxic emissions.

Among the fuel variables to be studied, sulfur 

has been identified as most critical to this research. 

The Diesel Emission Control – Sulfur Effects 

(DECSE) project [1], a predecessor to this effort, 

examined the effect of sulfur on individual emission 

control devices including NOx adsorber catalysts, 

DPFs, diesel oxidation catalysts (DOC), and leanNOx catalysts. This testing showed that efficiency of 

NOx adsorber catalysts is significantly effected by 

sulfur in the diesel fuel [2]. This project provides a 

more thorough investigation of sulfur effects and 

uses modern hardware and robust electronic controls 

with systems incorporating both NOx and PM control 

devices. Emission control system durability, as a 

function of fuel sulfur content, will be examined in 

tests up to 1000 hours in duration.

Approach

The 2001 Audi A4 Avant test vehicle (Figure 1) 

with a 1.9 liter TDI engine (100 KW at 4000 rpm) 

(Figure 2) will be equipped with appropriately 

designed emission control devices and the necessary 

regenerative control hardware and electronics to 

conduct this fuel study. As illustrated in Figure 3, a 

significant reduction in tail pipe emissions over the 

current European calibration for this vehicle will be 

required for this project.

In order to make the goals of this project possible 

and limit the reduction efficiencies required by the 

aftertreatment devices significant modifications have 

been made to the test engine to lower engine-out 

emissions, including: installation of common rail fuel 

injectors, addition of an aluminum cylinder head, and 

engine calibration changes (for lower engine-out 

NOx and more favorable exhaust temperature 

profiles). In addition, dual wall insulated exhaust 

components will be used to retain heat for the ECS. 

MECA has provided emission control devices for 

two different ECS configurations, both single leg 

systems. Figure 4 shows the basic configuration for 

both systems, with the key difference being the 

formulation of the pre-catalyst. In one system the 

pre-catalyst will serve both a NOx adsorbing and 

oxidizing function, while in the second system the 

pre-catalyst will only serve a NOx adsorbing 

function. This project is comprised of three major 

tasks as described in the following.

Figure 1. Audi A4 Avant Test Vehicle

Figure 2. 1.9L TDI Test Engine

Figure 3. Project Emission Reduction Targets
Fuels for Advanced CIDI Engines FY 2002 Progress Report

19

Task A involves development of the test platform 

including setup, integration, and optimization of the 

engine and vehicle, emission control system (ECS), 

associated electronic controls and development of 

thermal management strategies. This task includes 

the design of post injection strategies that will 

provide in-cylinder secondary fuel for NOx adsorber 

catalyst regeneration. This task also includes 

baseline tests to characterize engine-out emissions 

(no catalysts) during transient and steady-state 

operation. Baseline tests will be conducted with 8- 

and 15-ppm sulfur fuels and a low sulfur refinery fuel 

(called BP15).

Task B involves system performance and aging 

evaluations using fuels with varying fuel sulfur 

content. Performance evaluations on the FTP, US06 

and HFET will be conducted every 50 hours up to 

300 hours using 8- and 15-ppm S fuels. Both ECSs 

will be tested with each fuel. Aging will continue on 

one of these systems for an additional 1000 hours 

using the 15-ppm S fuel to determine longer term 

aging impacts. A limited amount of testing will also 

be conducted with 30-ppm S fuel to determine the 

impact of misfueling with a higher sulfur fuel.

Task C is a study of fuel properties other than 

sulfur to determine their impact on the NOx adsorber/

DPF system. This testing will include an ultra-low 

sulfur (<15-ppm S) refinery fuel and up to three 

additional fuels. Each fuel will be tested to 

determine its effect on the regeneration and 

desulfurization strategies developed in Task A. No 

aging tests will be conducted in Task C.

A full suite of emissions will be measured during 

Task A baseline testing and Task B aging tests. They 

include the following:

NOx

CO

HC (hydrocarbons)

CO2 (carbon dioxide)

PM (including detailed compositional analysis)

Benzene

1,3 butadiene

Formaldahyde

Acetaldehyde

N2O (nitrous oxide)

NH3 (ammonia)

SO2 (sulfur dioxide)

H2S (hydrogen sulfide)

Nitroxyalkanes

Results

A majority of the effort to date has been devoted 

to procurement and setup of the testing platforms as 

well as development of strategies for regeneration 

and desulfurization. A limited amount of baseline 

and engine-out data has been collected. Aging and 

evaluations testing will generate a significant body of 

data in FY 2003.

References

1. http://www.ott.doe.gov/decse/

2. U.S. Department of Energy, Engine 

Manufacturers Association, Manufacturers of 

Emission Controls Association, “Diesel 

Emission Control – Sulfur Effects (DECSE) 

Program – Phase I Interim Data Report No. 2: 

NOx Adsorber Catalysts,” October 1999.

Figure 4. Emission Control System Architecture
Fuels for Advanced CIDI Engines FY 2002 Progress Report

20

B. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Pick-up/SUV 

Project)

Matthew J. Thornton (Primary Contact), Shawn Whitacre, Wendy Clark

National Renewable Energy Laboratory

1617 Cole Blvd., MS 1633

Golden, CO 80401

(303) 275-4267; fax: (303) 275-4273; e-mail: matthew_thornton@nrel.gov

DOE Technology Development Managers: 

John Garbak: (202) 586-1723; fax: (202) 586-9811; e-mail: John.Garbak@ee.doe.gov

Stephen Goguen: (202) 586-8044; fax: (202) 586-2476; e-mail: Stephen.Goguen@ee.doe.gov

Kevin Stork: (202) 586-8306; fax: (202) 586-2476; e-mail: Kevin.Stork@ee.doe.gov

Other Participants: American Petroleum Institute (API), Engine Manufacturers Association (EMA), 

Manufacturers of Emissions Control Association (MECA), U. S. Environmental Protection Agency 

(EPA), Oak Ridge National Laboratory (ORNL), California Air Resources Board (CARB)

Subcontractor: Southwest Research Institute, San Antonio, TX 

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects on Exhaust Emission Control System Technology

C. Emission Control System Degradation

D. Sulfur Impacts

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Demonstrate the potential of NOx adsorber technology in combination with diesel particulate filters, 

advanced fuels, and advanced engine controls to achieve stringent emission levels while maintaining 

high fuel economy. Achieve stringent Tier 2 Bin 5 light-duty emission standards with limits of 0.07 g/

mi NOx and 0.01 g/mi particulate matter (PM).

• Determine the necessary fuel sulfur level and other fuel properties that will enable these systems. The 

fuel sulfur levels tested will be representative of those required to be available beginning June 2006 

(<15 ppm S).

Approach

A model year 2002 Chevrolet 2500 Series Silverado with a 6.6 liter Duramax engine (300 HP at 3100 

rpm) with a Bosch common rail fuel injection system, integrated exhaust gas recirculation (EGR), charge 

air cooler, and a center mounted turbine will be used as the test vehicle for this project. This vehicle will 

be equipped with appropriately designed emission control devices and the necessary regenerative control 

hardware and electronics to meet the project objectives. This project includes three major tasks:
Fuels for Advanced CIDI Engines FY 2002 Progress Report

21

• Task A involves development of the test platform including setup, integration, and optimization of the 

engine; thermal management; emission control system (ECS) and associated electronic controls; and 

baseline (engine-out) testing of regulated and unregulated emissions.

• Task B involves system performance and aging tests using fuels with varying sulfur content (8, 15, 30 

ppm S) and periodic evaluations of emissions over the FTP, US06, and HFET driving cycles during 

aging tests up to 1500 hours duration. Two ECS architectures will be developed and tested: a single 

leg system (System A) and a dual leg system (System B).

• Task C will investigate fuel properties other than sulfur and determine their impact on the NOx

adsorber/diesel particulate filter (DPF) system. This testing will include an ultra-low sulfur (<15 ppm 

S) refinery fuel and up to two additional fuels. No aging tests will be conducted in Task C.

Accomplishments

• Acquired test vehicles and engines, and installed two engines in emissions test cells.

• Designed ECS architecture and completed exhaust system modifications. 

• Integrated an external electronic controller with the base engine electronics to control post injection 

and lean and rich cycling conditions necessary for catalyst regeneration.

• Developed and tested rapid warm-up procedures and other thermal management approaches.

• Developed protocols for sampling and analysis of unregulated toxic emissions.

• Completed initial ECS system regeneration and desulfurization strategies.

Future Directions

• Complete the development of catalyst regeneration and desulfurization strategies (Task A).

• Conduct durability testing with fuels of varying sulfur content (Task B).

• Conduct testing of other fuel properties (Task C).

Introduction

The Advanced Petroleum Based Fuels - Diesel 

Emission Control (APBF-DEC) activity is a joint 

government/industry research effort to determine the 

best combinations of low-sulfur diesel fuels, 

lubricants, diesel engines, and emission control 

systems to meet projected emission standards for the 

2002 to 2010 time period. The project leverages the 

participation of several multi-industry working 

groups that direct five individual projects.

This project aims to demonstrate the viability of 

combining NOx adsorber catalysts and DPF 

technologies in combination with clean fuels, 

advanced engines and electronic controls to achieve 

stringent emission levels while maintaining high fuel 

economy. Specifically, this project will identify the 

fuels needed to enable these technologies for use in 

light-duty vehicles. The goal for this platform is to 

meet stringent Tier 2 Bin 5 light-duty emission 

standards with limits of 0.07 g/mi NOx and 0.01 g/mi 

PM. Another critical focus of this project is the 

characterization of currently unregulated, but 

potentially toxic emissions.

Among the fuel variables to be studied, sulfur 

has been identified as most critical to this research. 

The Diesel Emission Control - Sulfur Effects 

(DECSE) project [1], a predecessor to this effort, 

examined the effect of sulfur on individual emission 

control devices including NOx adsorber catalysts, 

DPFs, diesel oxidation catalysts (DOC), and leanNOx catalysts. This testing showed that efficiency of 

NOx adsorber catalysts is significantly affected by 

sulfur in the diesel fuel [2]. This project provides a 

more thorough investigation of sulfur effects and 

uses modern hardware and robust electronic controls 

with systems incorporating both NOx and PM control 

devices. Emission control system durability, as a 

function of fuel sulfur content, will be examined in 

tests up to 1500 hours in duration.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

22

Approach

A model year 2002 Chevrolet 2500 Series 

Silverado (Figure 1) with a 6.6 liter Duramax engine 

(300 HP at 3100 rpm) (Figure 2) will be equipped 

with appropriately designed emission control devices 

and the necessary regenerative control hardware and 

electronics to meet project objectives. A significant 

reduction in tailpipe emissions over the current 

California calibration for this vehicle will be required 

to meet the emissions objectives of this project.

In order to make the objectives of this project 

possible and limit the reduction efficiencies required 

by the aftertreatment devices, significant 

modifications have been made to the test engine to 

lower engine-out emissions. These include 

installation of low pressure EGR, a turbo by-pass 

system, and engine calibration changes (for lower 

engine-out NOx and more favorable exhaust 

temperature profiles). In addition, secondary 

injection and dual wall insulated exhaust components 

will be used to retain heat for the ECS. MECA has 

provided emission control devices for two different 

ECS configurations: a single leg system (System A) 

and a dual leg system (System B). Figures 3 and 4 

show the basic configuration for both systems. 

System A is a simple configuration which will 

minimize the packaging difficulties and catalyst 

costs, while System B will minimize NOx breakthrough as well as fuel consumption penalties 

associated with regeneration, but will be more 

complex and expensive. This project includes three 

major tasks:

Task A involves development of the test platform 

including setup, integration, and optimization of the 

engine and vehicle, emission control system (ECS), 

associated electronic controls, and development of 

thermal management strategies. This task includes 

the design of post injection strategies that will 

provide in-cylinder secondary fuel for NOx adsorber 

catalyst regeneration. This task also includes 

Figure 1. 2002 Chevrolet 2500 Series Silverado 

Figure 2. 6.6 Liter Duramax Engine 

Figure 3. Single-leg ECS Configuration (System A)

Figure 4. Double-leg ECS Configuration (System B)
Fuels for Advanced CIDI Engines FY 2002 Progress Report

23

baseline tests to characterize engine-out emissions 

(no catalysts) during transient and steady-state 

operation. Baseline tests will be conducted with 8 

and 15 ppm sulfur fuels and a low sulfur refinery fuel 

(called BP15).

Task B involves system performance and aging 

evaluations using fuels with varying fuel sulfur 

content. Performance evaluations on the FTP, US06 

and HFET driving cycles will be conducted every 50 

hours up to 300 hours using 8 and 15 ppm sulfur 

fuels. Both ECSs will be tested with each fuel. 

Aging will continue on one of these systems for an 

additional 1500 hours using the 15 ppm sulfur fuel to 

determine longer term aging impacts. A limited 

amount of testing will also be conducted with 30 

ppm sulfur fuel to determine the impact of misfueling 

with a higher sulfur fuel.

Task C is a study of fuel properties other than 

sulfur content to determine their impact on the NOx

adsorber/DPF system. This testing will include an 

ultra-low sulfur (<15 ppm sulfur) refinery fuel and 

up to two additional fuels. Each fuel will be tested to 

determine its effect on the regeneration and 

desulfurization strategies developed in Task A. No 

aging tests will be conducted in Task C.

A full suite of emissions will be measured during 

Task A baseline testing, Task B aging tests, and Task 

C. They include the following:

NOx

CO

HC (hydrocarbons)

CO2 (carbon dioxide)

PM (including detailed compositional analysis)

Benzene

1,3 butadiene

Formaldahyde

Acetaldehyde

N2O (nitrous oxide)

NH3 (ammonia)

SO2 (sulfur dioxide)

H2S (hydrogen sulfide)

Nitroxyalkanes

Results

A majority of the effort to date has been devoted 

to procurement and setup of the testing platforms as 

well as development of strategies for regeneration 

and desulfurization. A limited amount of baseline 

and engine-out data has been collected. Aging and 

evaluations testing will generate a significant body of 

data in FY 2003.

References

1. http://www.ott.doe.gov/decse/

2. U.S. Department of Energy, Engine 

Manufacturers Association, Manufacturers of 

Emission Controls Association, "Diesel Emission 

Control - Sulfur Effects (DECSE) Program - 

Phase I Interim Data Report No. 2: NOx Adsorber 

Catalysts," October 1999
Fuels for Advanced CIDI Engines FY 2002 Progress Report

24

C. Durability of NOx Adsorbers Using Ultra-Low Sulfur Fuels (Heavy-Duty 

Project)

Shawn D. Whitacre (Primary Contact), Wendy Clark

National Renewable Energy Laboratory

1617 Cole Blvd., MS 1633

Golden, CO 80401

(303) 275-4267, fax: (303) 275-4415, e-mail: shawn_whitacre@nrel.gov

DOE Technology Development Managers: 

Stephen Goguen: (202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Kevin Stork: (202) 586-8306, fax: (202) 586-1600, e-mail: Kevin.Stork@ee.doe.gov

Other Participants: American Chemistry Council, American Petroleum Institute (API), Engine 

Manufacturers Association (EMA), Manufacturers of Emissions Control Association (MECA), U. S. 

Environmental Protection Agency (EPA), Oak Ridge National Laboratory (ORNL), California Air 

Resources Board (CARB), South Coast Air Quality Management District (SCAQMD)

Main Subcontractor: Ricardo, Inc., Burr Ridge, Illinois

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects of Exhaust Emission Control System Technology

C. Emission Control System Degradation

D. Sulfur Impacts

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Demonstrate the viability of achieving future emissions standards for heavy-duty engines using 

nitrogen oxides (NOx) adsorber catalyst and diesel particle filter (DPF) technologies without 

significantly compromising fuel economy. 

• Determine the necessary fuel sulfur level and other fuel properties that will enable these systems. The 

fuel sulfur levels tested will be representative of those required to be available beginning June 2006 

(<15 parts per million [ppm] sulfur [S]).

Approach

• A Cummins ISX engine (15L, 475 horsepower [hp]) with integrated exhaust gas recirculation (EGR) 

and variable geometry turbine (VGT) has been supplied to the project. This engine will be equipped 

with appropriately designed emission control devices and the necessary regenerative control hardware 

and electronics to conduct this fuel study, which encompasses three major tasks:

- Task A involves development of the test platform including setup, integration, and optimization of 

the engine, emission control system (ECS), and associated electronic controls; modeling to 

determine appropriate regeneration and desulfurization strategies; and baseline (engine-out) testing 

of regulated and unregulated (toxic) emissions.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

25

- Task B involves system performance and aging tests using fuels with varying sulfur content (8, 15, 

30 ppm S) and periodic evaluations (transient and steady-state) of emissions during aging tests up to 

1500 hours of operation. Two ECS architectures will be developed and tested: a single leg system 

and a twin-bed (dual NOx adsorber catalysts) system.

- Task C will investigate fuel properties other than sulfur and determine their impact on the NOx

adsorber/DPF system. This testing will include an ultra-low sulfur (<15 ppm S) refinery fuel and up 

to three additional fuels. No aging tests will be conducted in Task C.

Accomplishments

• Installed ISX engine in emissions test cell.

• Designed and installed in-cylinder secondary injection system.

• Integrated an external electronic controller with the base engine electronics to control lean and rich 

exhaust conditions necessary for catalyst regeneration.

• Developed operational model of twin-bed NOx adsorber/DPF system.

• Developed protocols for sampling and analysis of unregulated toxic emissions.

• Completed baseline engine-out emissions tests.

Future Directions

• Complete the development of catalyst regeneration and desulfurization strategies (Task A).

• Conduct durability testing with fuels of varying sulfur content (Task B).

• Conduct testing of other fuel properties (Task C).

Introduction

The Advanced Petroleum Based Fuels - Diesel 

Emission Control (APBF-DEC) activity is a joint 

government/industry research effort to determine the 

best combinations of low-sulfur diesel fuels, 

lubricants, diesel engines, and emission control 

systems to meet projected emission standards for the 

2002 to 2010 time period. The project leverages the 

participation of several multi-industry working 

groups that direct five individual projects.

This project aims to demonstrate the viability of 

combining NOx adsorber catalysts and DPF 

technologies in combination with clean fuels, 

advanced engines and electronic controls to achieve 

stringent emission levels while maintaining high fuel 

economy. Specifically, this project will identify the 

fuels needed to enable these technologies for use in 

heavy-duty on-highway engines. For these engines, 

a NOx standard of 0.2 g/bhp-hr and 0.01 g/bhp-hr 

ppm will be phased in between 2007 and 2010. 

These emission levels must be achievable not only 

over the transient HD Federal Test Procedure, but 

also in other modes of operation. Another critical 

focus of this project is the characterization of 

currently unregulated, but potentially toxic 

emissions.

Among the fuel variables to be studied, sulfur 

has been identified as most critical to this research. 

The Diesel Emission Control - Sulfur Effects 

(DECSE) project [1], a predecessor to this effort, 

examined the effect of sulfur on individual emission 

control devices including NOx adsorber catalysts, 

DPFs, diesel oxidation catalysts (DOC), and leanNOx catalysts. This testing showed that efficiency of 

NOx adsorber catalysts is significantly affected by 

sulfur in the diesel fuel [2]. This project provides a 

more thorough investigation of sulfur effects and 

uses modern hardware and robust electronic controls 

with systems incorporating both NOx and PM control 

devices. Emission control system durability, as a 

function of fuel sulfur content, will be examined in 

tests up to 1500 hours in duration.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

26

Approach

The engine selected for this study is a Cummins 

ISX, a 15L, 500 hp inline, 6-cylinder engine with 

dual overhead camshafts. It is equipped with 

integrated EGR and a VGT and is calibrated to meet 

the 2004 HD emission standards (2.5 g/bhp hr NOx, 

0.1 g/bhp hr PM) as received. Additional 

modifications have been made by the subcontractor, 

including: installation of secondary in-cylinder fuel 

injectors (Figure 1), and engine calibration changes 

(for lower engine-out NOx and more favorable 

exhaust temperature profiles). MECA has provided 

emission control devices for two different ECS 

configurations: a single leg system (System A, 

Figure 2), and a twin-bed architecture (System B, 

Figure 3). The project involves three major tasks.

Task A involves development of the test 

platform, including setup, integration, and 

optimization of the engine, emission control system 

(ECS), and associated electronic controls. This task 

includes the design and installation of supplemental 

injectors that will provide in-cylinder secondary fuel 

for NOx adsorber catalyst regeneration. Modeling is 

being conducted to determine the appropriate 

regeneration and desulfurization conditions for 

optimal performance and system durability. This 

task also includes baseline tests to characterize 

engine-out emissions (no catalysts) during transient 

and steady-state operation. Baseline tests will be 

conducted with 8 and 15 ppm sulfur fuels and a low 

sulfur refinery fuel (called BP15).

Task B involves system performance and aging 

evaluations using fuels with varying fuel sulfur 

content. Performance evaluations, including the HD 

Federal Test Procedure and 13-mode steady-state 

tests, will be conducted every 50 hours up to 300 

hours using 8 and 15 ppm S fuels. Both systems (A 

and B) will be tested with each fuel. Aging will 

continue on one of these systems for an additional 

1000-1200 hours using the 15 ppm S fuel to 

determine longer term aging impacts. A limited 

amount of testing will also be conducted with 30 

ppm S fuel to determine the impact of misfueling 

with a higher sulfur fuel.

Task C is a study of fuel properties other than 

sulfur to determine their impact on the NOx adsorber/

DPF system. This testing will include an ultra-low 

sulfur (<15 ppm S) refinery fuel and up to three 

additional fuels. Each fuel will be tested to 

determine its effect on the regeneration and 

desulfurization strategies developed in Task A. No 

aging tests will be conducted in Task C.

Figure 1. Installation of Secondary In-Cylinder Fuel 

Injectors

Figure 2. Emission Control System 'A': Single Leg 

Architecture

Figure 3. Emission Control System 'B': Twin Bed 

Architecture
Fuels for Advanced CIDI Engines FY 2002 Progress Report

27

A full suite of emissions will be measured during 

Task A baseline testing, Task B aging tests, and Task 

C. They include the following:

• NOx

• CO

• HC (hydrocarbons)

• CO2 (carbon dioxide)

• PM (including detailed compositional 

analysis)

• Benzene

• 1,3 butadiene

• Formaldahyde

• Acetaldehyde

• N2O (nitrous oxide)

• NH3 (ammonia)

• SO2 (sulfur dioxide)

• H2S (hydrogen sulfide)

Results

A majority of the effort to date has been devoted 

to procurement and setup of the testing platforms as 

well as development of strategies for regeneration 

and desulfurization. A limited amount of baseline 

(engine-out) data has been collected. Aging and 

evaluations testing will generate a significant body of 

data in FY 2003.

References

1. http://www.ott.doe.gov/decse/

2. U.S. Department of Energy, Engine 

Manufacturers Association, Manufacturers of 

Emission Controls Association, "Diesel Emission 

Control - Sulfur Effects (DECSE) Program - 

Phase I Interim Data Report No. 2: NOx Adsorber 

Catalysts," October 1999
Fuels for Advanced CIDI Engines FY 2002 Progress Report

28

D. Lubricant Property Impact on CIDI Emission Control System Durability

Shawn D. Whitacre (Primary Contact), Wendy Clark

National Renewable Energy Laboratory

1617 Cole Blvd., MS 1633

Golden, CO 80401

(303) 275-4267, fax: (303) 275-4415, e-mail: shawn_whitacre@nrel.gov

DOE Technology Development Managers: 

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Stephen J. Goguen: (202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Other Participants: American Chemistry Council, American Petroleum Institute (API), Engine 

Manufacturers Association (EMA), Manufacturers of Emissions Control Association (MECA), Oak 

Ridge National Laboratory (ORNL)

Main Subcontractor: Automotive Testing Laboratories, Inc., East Liberty, Ohio

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects of Exhaust Emission Control System Technology

C. Emission Control System Degradation

D. Sulfur Impacts

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Determine the impact of lubricant properties and composition on engine-out/catalyst-in emissions.

• Determine if lubricant formulation impacts the performance and durability of diesel engine emission 

control systems (ECS).

• Develop guidelines for the specification of catalyst compatible lubricants required for use in future 

low-emissions diesel engines.

Approach

• Phase 1. Determine the impact of lubricant formulation (additives and basestock) on the emissions of 

a compressed ignition direction injection (CIDI) engine. Conventional and developmental additives 

blended with four different basestocks are tested in a medium-duty diesel engine.

• Phase 2. Develop a rapid catalyst aging protocol to accelerate studies to determine the impact of 

lubricant derived emissions on emission control system durability.

• Phase 3. Perform testing to study lubricant effects on NOx adsorber catalysts and selective catalytic 

reduction in combination with diesel particle filters.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

29

Accomplishments

• An International T444E (7.3L, V8) has been installed in an emissions test cell at ATL. The MY 1999 

engine has been upfit with exhaust gas recirculation (EGR) and closed crankcase ventilation (CCV) 

hardware similar to future base engine designs. 

• Test lubricants ranging in sulfur content between 0 and 6500 parts per million (ppm) and ash between 

0% and 1.85% have been prepared in four basestocks; one each from the four major base oil 

classifications (Group I-IV) as defined by API.

• All Phase I testing, including 12 additives and four basestocks, has been completed.

Future Directions

• The influence of the lubricant derived emission components on catalyst durability will be examined.

• A rapid aging protocol to accelerate lubricant effects testing will be developed and utilized to 

determine if consumed diesel engine oil impacts catalyst life.

Introduction

The Diesel Emission Control - Sulfur Effects 

project [1] quantified the impact of diesel fuel sulfur 

on the performance and short-term durability of 

diesel emission control devices. The acute sensitivity 

of certain of these devices highlighted the need to 

study another source of sulfur and other potential 

poisons - specifically the diesel lubricating oil.

To address this concern, a research project to 

study lubricant formulation (basestocks and 

additives) effects on diesel emission control systems 

is entering its second year. The research is being 

conducted as part of the Department of Energy's 

Advanced Petroleum Based Fuels - Diesel Emission 

Control activity and leverages participation from an 

inter-industry working group that guides the 

research.

It is anticipated that the results of this study will 

be critical in defining the needs of future lubricant 

formulations for both light-duty and heavy-duty 

diesel engines. Should a need for substantial 

lubricant reformulations be identified, industry will 

require significant development time to research 

'catalyst compatible' formulations that are costcompetitive and that continue to deliver superior 

engine protection and long life that engine customers 

demand. In addition, engine manufacturers 

recognize that the lubricant reformulations may drive 

the need for more robust engine hardware that is 

tolerant of modified oil chemistry, an endeavor 

requiring significant development time as well.

Approach

This project is being conducted in three 

consecutive phases. The first phase, which identified 

and characterized lubricant derived emissions 

constituents, has been completed. This testing 

utilized a medium-duty International T444E engine 

that was equipped with EGR and CCV (Figure 1). A 

matrix of conventional and experimental lubricant 

additive packages blended with various petroleumbased and synthetic basestocks was evaluated. 

Twelve additive packages were selected to provide a 

range of various components including ash content, 

sulfur, zinc, phosphorus, etc. The four basestocks 

tested span the available production approaches and 

include products of varying sulfur content, volatility, 

Figure 1. International T444E Engine Installation
Fuels for Advanced CIDI Engines FY 2002 Progress Report

30

and degree of saturation. Emissions were sampled 

during a four mode steady-state operating cycle and 

included: gaseous hydrocarbons, carbon monoxide, 

sulfur dioxide, nitrogen oxides, and particulate 

matter (PM). The PM was further analyzed for 

sulfate and nitrate fractions, soluble organic fraction, 

metals content, and polycyclic aromatic hydrocarbon 

content.

Follow-up work is being conducted to determine 

if and to what extent these lubricant related emissions 

species impact the performance and durability of 

emissions control devices designed to reduce NOx

and PM emissions from diesel engines. A protocol 

for rapidly aging emission control devices and 

determining lubricant effects is being developed. 

This test protocol will then be utilized to determine if 

lubricant sulfur, ash, and certain metals need to be 

controlled to meet useful life standards placed on 

emission control systems.

Results

Mass balances were conducted for each of the 

critical parameters. Predicted emission rates for each 

species were estimated based upon fuel and lubricant 

properties and fuel and lubricant consumption rates. 

Data presented here compares predicted rates with 

the actual measured rates. As evidenced by Figure 2, 

calcium emission rates are directly correlated with 

the concentration of calcium in the oil, independent 

of any given additive formulation. However, only 

46% of the calcium in the oil is emitted and 

measured in the PM. Several theories, including 

deposition in the lube oil filter, have been proposed. 

Clearly, though, the oil is not uniformly consumed.

Figure 3 illustrates the mass balance results for 

zinc. Like calcium, zinc emissions are directly 

correlated to the concentration in the tested 

formulation with 43% estimated recovery; however, 

one formulation showed a measurable deviation, 

suggesting that this oil is consumed by a mechanism 

dissimilar to the rest. Because most of the zinc is 

derived from the very surface active zinc dialkyldithiophosphate (ZDDP) antiwear agent, it is 

believed that a majority of the "missing" zinc has 

been deposited on metal surfaces.

Figure 2. Calcium in PM Emissions

Figure 4. Phosphorus in PM emissions

Figure 3. Zinc in PM Emissions
Fuels for Advanced CIDI Engines FY 2002 Progress Report

31

Phosphorus emissions are shown in Figure 4. 

With the exception of one oil, the recovery of 

phosphorus is consistent with predictions (90%) and 

highly correlated with the phosphorus concentration 

of the oil. The emission rate from "Oil C" was nearly 

four times the predicted rate, suggesting that it is 

preferentially consumed in this formulation. This 

particular formulation contains a very low zinc 

concentration, suggesting that it utilizes nontraditional anti-wear chemistry (i.e. no ZDDP). As 

such, the phosphorus is more volatile and is emitted 

at a higher rate than predicted by the measured total 

oil consumption rate. This is a critical finding 

because it illustrates the danger in specifications 

utilizing chemical limits (e.g. controlling phosphorus 

levels in oils may not have the desired effect).

Because of the well documented impact of sulfur 

(in particular, SO2) on the durability of NOx adsorber 

catalysts [2], particular scrutiny has been given to the 

impact of lubricant derived sulfur on emissions of 

this catalyst poison. Figure 5 shows SO2 emissions 

for the various additive and basestock combinations 

tested here. Additives A-F were tested in each of the 

four basestock groups while additives G-L (and the 

reference oil R) were tested exclusively in the Group 

II stock. Of the four basestocks tested, only the 

Group I stock had significant sulfur content (approx 

5000-ppm S); the others were hydrotreated (II and 

III) or synthetic (IV, poly-alpha olefin). For 

reference, additive B contained almost no sulfur 

while additive E contributed 6590 ppm S in the 

additive system alone. In general, SO2 emissions 

rates do not correlate well with the concentrations in 

the oil. Perhaps the most significant comparisons are 

between the B and E blends. While the total sulfur 

content with E is much greater than B, SO2 emissions 

are quite similar within a given basestock. 

Basestocks do not have a significant effect either, 

although the synthetic (Group IV) basestock tends to 

give the lowest SO2 emissions, independent of the 

additive system.

Conclusions

Sulfur content in the oil is generally related to 

sulfur emissions in the exhaust, but the type of sulfur 

compound in the oil can have a significant impact on 

the SO2 emission rate. This is generally true for 

phosphorus emissions as well.

Some compounds, such as zinc and calcium, may 

be found in the exhaust in lower quantities, on 

average, than predicted by the measured oil 

consumption.

References

1. http://www.ott.doe.gov/decse/

2. U.S. Department of Energy, Engine 

Manufacturers Association, Manufacturers of 

Emission Controls Association, "Diesel Emission 

Control - Sulfur Effects Program - Phase I Interim 

Data Report No. 2: NOx Adsorber Catalysts," 

October 1999

Figure 5. Base Oil and Additive Effects on SO2

Emissions
Fuels for Advanced CIDI Engines FY 2002 Progress Report

32

E. Demonstration of Potential for Selective Catalytic Reduction and Diesel 

Particulate Filters

Ralph McGill (Primary Contact)

Oak Ridge National Laboratory

National Transportation Research Center

2360 Cherahala Boulevard

Knoxville, TN 37923

(865) 946-1228, fax: (865) 946-1248, e-mail: mcgillrn@ornl.gov

DOE Technology Development Manager: Steve Goguen

(202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Main Subcontractor: Southwest Research Institute (SwRI), San Antonio, Texas

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B.Fuel Property Effects on Exhaust Emission Control System Technology

Tasks

3.Fuel & Lubricant Properties - Exhaust Emissions Control and Emissions

Objectives

• Demonstrate the low-emissions performance of advanced diesel engines operating on advanced fuels, 

and equipped with low-pressure-loop exhaust gas recirculation (EGR) plus urea selective catalytic 

reduction (SCR) and diesel particulate filters (DPF).

• Determine the regulated and unregulated emissions with and without emission controls.

• Examine the durability of the emission control systems.

• Determine toxic and unregulated emission levels.

• Evaluate the sensitivities of the emission controls to fuel variables.

Approach

• Set up a heavy-duty engine in an emissions test cell to optimize emission reduction performance of 

two different emission control systems utilizing urea SCR (System A and System B). 

• Apply a low-pressure-loop EGR system to reduce engine-out nitrogen oxides (NOx) to ~ 2.0 - 2.5 

grams per horsepower per hour (g/hp-hr) or less.

• Add emission control system(s) including diesel particulate filters and SCR systems with urea 

injection to reduce tailpipe emissions of both NOx and particulate matter (PM). (Two different 

emission control systems S Systems A and B S both comprised of DPF and SCR catalysts will be 

evaluated.)

• Integrate controls and optimize performance to reach the lowest possible emissions of NOx and PM for 

both systems.

• Perform 6,000 hour durability tests simultaneously with Systems A and B, and measure emissions S

regulated and unregulated S at 2,000 hour intervals.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

33

Accomplishments

• A Caterpillar C-12 engine was installed in an emissions test cell and tested in its as-received 

configuration with D2 diesel fuel containing 350 ppm sulfur. Emissions results for the baseline over 

the U.S. heavy-duty transient cycle were ~ 3.55 g/hp-hr NOx and ~ 0.065 g/hp-hr PM. Results over the 

steady-state European OICA cycle were 4.82 g/hp-hr NOx and 0.031 g/hp-hr PM.

• The engine was fitted with a low-pressure-loop cooled EGR system, provided by STT-Emtech in 

Sweden and a diesel particulate filter (part of System A) provided by MECA, and the systems were 

optimized for low engine-out NOx. Engine-out NOx over the transient cycle with the EGR system and 

using Diesel Emission Control - Sulfur Effects (DECSE) program 3-ppm sulfur fuel was reduced to 

1.5 g/hp-hr. Over the steady-state OICA cycle, NOx emissions were reduced to 2.32 g/hp-hr. 

Particulate emissions for both tests remained below 0.01 g/bhp-hr.

• The urea SCR catalyst of System A was added to the emission control system along with urea injection 

systems provided by Robert Bosch, and the calibration of the SCR system for NOx reductions was 

engineered. Results on the steady-state OICA test showed tailpipe NOx reduced to only 0.17 g/hp-hr. 

The calibration is being optimized at this time for the transient cycle.

• A test cell has been set up at Southwest Research Institute (SwRI) for the durability tests using two 

C12 engines provided by Caterpillar.

Future Directions

• Calibration of System A for low emissions will be completed soon. Then, a matrix of emission tests 

with the different fuels will be carried out before the system is installed on one of the durability 

engines for the beginning of the 6,000-hour durability test.

Introduction

Southwest Research Institute (SwRI) is the 

contractor for this Advanced Petroleum-Based Fuels 

- Diesel Emission Control (APBF-DEC) project, and 

technical guidance is provided by the APBF-DEC 

working groups. Caterpillar has provided 12-liter 

engines for the project, and Manufacturers of 

Emission Controls Association (MECA) has 

provided two exhaust emission control systems. 

Each emission control system includes a diesel 

particulate filter combined with SCR catalysts. 

Low-pressure-loop EGR systems were provided by 

STT-Emtech in Sweden, while Robert Bosch 

Corporation has provided the urea injection systems.

The plan is to optimize emissions performance 

with two different catalyst systems (Systems A and 

B), each comprised of DPF and urea SCR catalysts. 

After optimization, the emissions performance will 

be characterized with 4 different fuels - DECSE fuel 

with sulfur levels of 3, 8, and 15 ppm plus a BP 

refinery fuel with nominally 15 ppm sulfur. A 

limited test will be performed with DECSE 30 fuel 

(30 ppm sulfur). Emissions will be thoroughly 

characterized for these tests, including unregulated 

emissions of interest plus some potentially 

problematic toxics emissions.

Following all the emissions tests with each 

system, the systems will be set up in a durability test 

cell, where they will undergo 6,000 hours of 

durability testing with emissions tests at the 2,000, 

4,000, and 6,000-hour points.

Approach and Results

The first system has been set up in an emissions 

test cell at SwRI; a schematic of the system design is 

illustrated in Figure 1. A dual-leg exhaust system, 

employing two DPFs and SCR catalysts provided by 

the same manufacturer(s) was chosen to minimize 

the increase in back pressure and for other practical 

considerations.

The engine was first baselined for emissions and 

performance in an as-received condition using 

standard D2 fuel (of approximately 350 ppm sulfur 

content). Baselining consisted of running both the 

U.S. transient test cycle and the European OICA 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

34

cycle. Results for these tests are shown in Figures 2 

and 3 respectively. Note that the baseline NOx

emissions are ~ 3.54 g/hp-hr and 4.82 g/hp-hr for the 

transient and steady-state, cycles respectively.

Next, the EGR system (along with the DPF for 

System A) was installed on the engine and calibrated 

for minimum engine-out NOx while maintaining 

other parameters such as fuel consumption. (Note 

that the DPF was used with the EGR system so that 

the gases recirculated would be as free as possible 

from soot. Refer to Figure 1.) Results for the final 

EGR calibration on the transient cycle are shown in 

Figure 4, where engine-out NOx has been reduced to 

1.46 g/hp-hr, and PM (after the DPF) has been 

reduced to 0.007 g/hp-hr. Results for the OICA cycle 

are shown in Figure 5, where engine-out NOx has 

been reduced to 2.32 g/hp-hr.

Figure 1. Test Setup

Figure 2. Transient Emissions - 350 ppm Certified 

2D Fuel - Two Hot Cycles 

* Data labels shown for only one of the cycles

Figure 3. Steady-State Emissions - Hot Cycle - 350 

ppm Certified 2D Fuel

Figure 4. Transient Emissions - EGR* and DECSE 

3 ppm Fuel - Two Hot Cycles 

Data labels shown for only one of the cycles

*

 EGR - Low-Pressure-Loop EGR with CB-DPF

Figure 5. Steady-State Emissions Comparison - as 

Received with Certified 350 ppm Sulfur 

and with EGR*

Data labels shown for EGR case only 

* EGR - Low-Pressure-Loop EGR with CB-DPF
Fuels for Advanced CIDI Engines FY 2002 Progress Report

35

The next step was to add the urea SCR catalyst of 

System A and the urea injection systems. 

Optimization of the entire system, now including the 

SCR system, is still under way, but some promising 

results can be seen on the OICA cycle as shown in 

Figures 6 and 7, where the NOx is reduced to 0.17 g/

hp-hr, and PM is 0.003 g/hp-hr.

Conclusions 

The calibration for System A will be completed 

very shortly at which time the emissions tests with 

the fuels matrix will be carried out. Following that, 

System A will be moved to the durability test cell 

while work will begin on System B to optimize and 

calibrate that system for minimum emissions.

Figure 6. Steady-State Emissions (HC, CO and PM) 

Development and Progress

Figure 7. Steady-State Emissions (NOx) Development 

and Progress
Fuels for Advanced CIDI Engines FY 2002 Progress Report

36

F. Urea SCR System Evaluation with Emphasis on Unregulated Emissions

John Storey (Primary Contact), Norberto Domingo

Oak Ridge National Laboratory

Network Technology Resource Center

2360 Cherahala Boulevard

Knoxville, TN 37932

(865) 946-1232, fax: (865) 946-1248, e-mail: storeyjm@ornl.gov

DOE Technology Development Manager: John Garbak

(202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Industry Participants: OMG-DMC2 Automotive Catalysts Division

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

 B. Fuel Property Effects on Exhaust Emission Control System Technology

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Evaluate the performance of urea selective catalytic reduction/diesel particulate filter (SCR/DPF) 

systems on a sports utility vehicle (SUV)-sized diesel engine

• Investigate the unregulated emissions from these systems utilizing realistic 2007 diesel fuels

Approach

• Tune system for steady-state and modal transient emissions performance

• Measure unregulated emissions during emissions evaluation of the SCR system using methods 

developed at Oak Ridge National Laboratory (ORNL) for the APBF-DEC project

Accomplishments

• Developed methods for measuring urea decomposition products 

• OMG SCR, DPF and ARIS 2000 urea injection system installed

• Installed engine, dynamometer, controls, and data acquisition at the ORNL Network Technology 

Resource Center

• Preliminary data from modal testing obtained to validate measurement techniques

Future Directions

• Continue to evaluate SCR catalyst 1 with ARCO ECD fuel and BP fuel (from APBF-DEC)

• Obtain steady-state regulated and unregulated emissions

• Obtain regulated emissions on modal transients

• Analyze data reduction and communicate results to partners

• Repeat with Catalyst 2
Fuels for Advanced CIDI Engines FY 2002 Progress Report

37

Introduction

Urea SCR has emerged as a promising 

technology for the reduction of oxides of nitrogen 

(NOx) from compressed ignition direct injection 

(CIDI) engines. Several groups have demonstrated 

emissions levels at or near the 2007 heavy-duty 

engine emission standards as well as Tier 2 emission 

levels for light-duty vehicles. The technology uses a 

urea solution injected into the exhaust as a source of 

ammonia, which then reacts with NOx on the catalyst 

to reduce NOx to diatomic nitrogen (N2).

In an ideal case, the urea dissociates completely 

in the exhaust to ammonia and carbon dioxide (CO2), 

as shown in Figure 1.

However, many other urea decomposition 

products are possible; Figure 2 shows a selection of 

compounds that have been detected in exhaust from 

an engine equipped with an SCR system. 

These and other unregulated emissions, such as 

ammonia (NH3) and N2O, are important to 

characterize both for potential health effects issues 

and as an indicator of catalyst system performance.

In this report, we describe an ongoing series of 

experiments to examine the performance and 

unregulated emissions from SCR/DPF systems.

Approach

A combined SCR-DPF system, provided by 

OMG-DMC2, is being investigated at the ORNL 

Fuels, Engines, and Emissions Research Center 

(FEERC). Figure 3 shows a schematic of the system. 

The oxidation catalyst provides heat and helps to 

convert NO to NO2, as the SCR prefers a 50:50 ratio 

of NO:NO2. Unlike another SCR-DPF system 

studied earlier [2], this system has the DPF 

downstream of the SCR catalyst. This arrangement 

allows the exhaust heat to be conserved to keep the 

SCR catalyst at high conversion levels. The engine 

is a Cummins B5.9 that is equipped with exhaust gas 

recirculation (EGR). Although this is a medium-duty 

engine, the exhaust flows and temperatures are 

similar to smaller, high-speed CIDI engines expected 

to be in service in SUVs in the near future. Figure 4 

is a photograph of the engine and system installed at 

the FEERC.

The urea injection system is an ARIS 2000 

system which has been described elsewhere [2]. This 

system can be programmed a priori to follow 

Figure 1. Ideal Formation of NH3 from Urea

Figure 2. Chemical Structures of Several Urea 

Decomposition Products

Figure 3. Schematic of the SCR-DPF System Used in 

this Study
Fuels for Advanced CIDI Engines FY 2002 Progress Report

38

transients, but it is not capable of true transient 

operation. Thus, for these experiments, steady-state 

operation will be used for the majority of unregulated 

emissions testing. In addition, programmed 

transients will be done to see if there are any unusual 

emissions due to transient operation.

 Two SCR formulations provided by OMGDMC2 will be evaluated, operating on two different 

fuels. The fuels were selected to represent possible 

refinery fuels that will be available in 2007. Arco 

ECD-1 is a 15 ppm sulfur fuel representative of a 

hydro-treated fuel. In addition, the BP refinery fuel, 

a hydro-cracked fuel and also 15 ppm sulfur, will be 

used in this study.

Several of the modes from the AVL 8 mode test 

were run. A micro-dilution system was used to dilute 

the exhaust for particulate matter (PM) and 

hydrocarbon (HC) measurements. Bag HCs were 

analyzed using an Entech Preconcentrator coupled to 

a Hewlett-Packard gas chromatography-mass 

spectrometer (GC-MS) system. Raw exhaust was 

collected in impingers containing a 70% solution of 

isopropanol in water for measurement of urea 

decomposition products. The impinger solutions 

were analyzed by capillary electrophoresis equipped 

with ultraviolet (UV) detection. PM samples were 

collected on 70 mm Pallflex Teflon-coated quartz 

fiber filters. A Fourier Transform Infrared (FTIR) 

and photoacoustic analyzer (PAS) were used to 

measure N2O and NH3 slip. An in-house UV 

absorption spectrometer was also implemented to get 

higher speed measurements of NH3.

Preliminary Results

This project is ongoing, so only some 

preliminary results from the first SCR formulation 

using the ARCO ECD-1 fuel are available. It was 

determined after these experiments that a 

malfunction in the urea injection system was causing 

excess reductant injection, so the results represent an 

upset condition, rather than proper operation. 

Unfortunately, our FTIR and PAS were unable to 

detect the excess NH3, so the extent of the problem 

was only realized after implementation of the UV 

system. It is believed that the excess NH3 was being 

retained in the sampling systems for the FTIR and 

the PAS, and thus was not able to be measured by 

these instruments.

Figure 5 shows NOx conversion results for the 

SCR and SCR-DPF combination at both a highspeed, high-load point (Mode 8) and a low-speed, 

high load point (Mode 4.) Note that the lower space 

velocity resulted in better conversion. We now 

believe this was due to the higher NOx level of Mode 

4. More of the excess NH3 was able to react with the 

higher NOx, resulting in better NOx conversion. 

Excess NH3 can often result in poor NOx conversion 

because the NH3 is converted to NOx either by the 

DPF or the internal catalyst in the 

chemiluminescence analyzer used to measure NOx.

After implementation of the UV instrument, the 

urea injection system could be tuned to limit NH3

Figure 4. Photograph of the SCR-DPF System 

Installed on a Cummins B5.9 Engine

Figure 5. NOx in and out of the system for AVL Mode 8 

and Mode 4. Note that 99% NOx conversion 

was achieved for Mode 8 after tuning injection 

system for low NH3 slip.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

39

slip. A re-check of Mode 8 showed 98-99% 

conversion under the low NH3 slip conditions.

Unregulated emissions were collected during this 

preliminary phase of the research. Impinger samples 

showed an excess of cyanic acid (see Figure 2) being 

generated during several of the modes. We believe 

this was due to the excess urea solution being 

injected. Bag HC speciation of the exhaust also 

indicated the formation of some unusual species. 

Figure 6 shows the ion chromatograms of exhaust 

samples taken during Mode 8 with and without urea 

injection. The particular ion chosen, m/z =30, is the 

marker for alkyl nitrate species, and thus each of the 

peaks corresponds to a different alkyl nitrate 

compound. While there is a small amount of alkyl 

nitrate being emitted from the DPF, the third trace 

shows a very large amount of a low molecular weight 

alkyl nitrate being generated by the SCR. This is 

very likely CH3NO3, methyl nitrate. Methyl nitrate 

is significant because it binds NOx such that the 

standard chemiluminescence detector is unable to 

detect NOx, and it is also a very reactive compound. 

As with the previous results, the generation of the 

methyl nitrate is believed to be due to the overinjection of urea solution and subsequent oxidation 

of cyanuric acid or another compound on the SCR 

catalyst.

While the preliminary results were unusual due 

to the excess of urea injected, the methods we have 

developed for unregulated emissions analysis worked 

very well, and we expect to have much better success 

in subsequent experiments with a properly 

functioning urea injection system.

Further work will focus on completion of the 

study using the two SCR formulations and the two 

fuels. Because of the unusual results with excess 

urea injection, we plan to study more mild excursions 

from normal operation. An important finding from 

this work will be the threshold of excess urea 

injection above which the unusual chemistry occurs. 

Summary

An SCR-DPF system has been installed and 

operated on a turbocharged, direct-injected diesel 

engine. Preliminary data on the system has been 

acquired, showing excellent NOx conversion under 

normal operation. Under conditions of excess urea 

injection, unusual species formed in the exhaust. The 

methods developed for the measurement of these 

species proved successful. The study will be 

completed this year.

References

1. Ball, James, “AA Toxicological Evaluation of 

Potential Thermal Degradation Products of Urea”, 

Technical report no. SRR-1999-0134. Ford Motor 

Company, Dearborn, MI. 1999.

2. J.F. Thomas, M.D. Kass, J.M. Storey, N. 

Domingo, R.L. Graves, T. Barber, “Targeting the 

EPA HD-FTP 2007 Emission Standards Using a 

Modern Diesel Engine with EGR and a SCR/CRT 

Aftertreatment System”, Proceedings of the 2002 

Technical Meeting, Central States Section, the 

Combustion Institute, April 2002.

Figure 6. GC-MS ion chromatograms (m/z = 30) of 

exhaust from a) DPF with no urea injection; b) 

DPF with urea injection; c) SCR with urea 

injection. The saturated signal in (c) indicates a

large amount of alky nitrate formation, most 

likely methyl nitrate.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

40

G. The Impact of Oxidation Catalysts on Diesel Engine Emissions

Wendy Clark, Matthew Thornton (Primary Contact)

National Renewable Energy Laboratory

1617 Cole Boulevard.

Golden, CO 80228

(303) 275-4468, fax: (303) 275-4415, e-mail: wendy_clark@nrel.gov

DOE Technology Development Manager: Kathi Epping 

(202) 586-7425, fax: (202) 586-9811, e-mail: Kathi.Epping@ee.doe.gov

Main Subcontractors: Coordinating Research Council, Inc., Alpharetta, Georgia; Southwest 

Research Institute, San Antonio, Texas

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

E. Toxic Emissions

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Assess the impact of diesel oxidation catalysts (DOC) in altering the particulate and gaseous emissions 

characteristics of a state-of-the-art light-duty diesel engine

• Test multiple diesel oxidation catalysts to characterize engine-out and tailpipe diesel emission 

characteristics 

• Evaluate an engine/oxidation catalyst technology combination that with appropriate particulate trap 

technology will meet Tier 2 emission standards, but only explore the effect of the DOC

Approach 

• Task 1 - Catalyst Procurement. Catalyst suppliers will provide diesel oxidation catalysts for 

evaluation. These catalysts will be close-coupled to the engine, and at least three advanced catalysts 

will be obtained for the study.

• Task 2 - Catalyst Degreening and Stabilization. Each catalyst will be installed on a vehicle operated 

for 4,000 miles to achieve stable performance. 

• Task 3 - Equipment Setup and Measurement Repeatability Verification. Theoretical analysis will be 

conducted to determine particle losses that may occur in the particulate sampling system for particle 

sizes ranging from 10 nanometers to 1 micron. Experimental loss analysis will also be performed in 

the micro-dilution tunnel using solid particle standards. Repeatability of all particulate and gaseous 

measurements will be determined in this task.

• Task 4 - Catalyst Evaluations with Low Sulfur Fuel. Evaluate three diesel oxidation catalysts using a 

light-duty 1999 Mercedes Benz C220 CDI vehicle equipped with a diesel-powered 2.2 liter OM611 

engine. The vehicle will use a fuel expected to be representative of the 2007 federal specification. The 

fuel will be procured with a sulfur content of approximately 10 parts per million (ppm). Test cycles 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

41

will be three steady-state conditions, the Federal Test Procedure, and the US06 to achieve exhaust 

temperatures ranging from 150bC to 450bC. 

• Task 5 - Chemical and Physical Characterization of Exhaust Emissions. Regulated gaseous emissions 

will be sampled and measured according to appropriate Environmental Protection Agency protocols as 

identified in the Code of Federal Regulation. In addition to dilute exhaust samples, second-by-second 

raw exhaust concentrations will be recorded prior to the close-coupled catalyst to assure consistent 

operation of the vehicle. Concurrent with the collection of gaseous emissions, a variety of particulate 

samples will be collected for physical and chemical characterization. Total particulate mass; volatile 

organic fraction of particulate; sulfate fraction of particulate; trace metals and inorganic ash; elemental 

and organic carbon particulate content; poly-aromatic hydrocarbons (PAHs), nitro-PAHs, and oxyPAHs; PM2.5 mass fraction, PM10 mass fraction, and particulate matter (PM) size distribution will 

each be measured for characterization of exhaust particulate matter upstream and downstream from the 

diesel oxidation catalyst. Speciation of gaseous emissions will also be determined, including C1 to C4 

species, C5-C12 species, benzene and toluene, and aldehydes and ketones upstream and downstream 

of the catalyst. SO2 to SO3 (sulfur oxides) conversion over the catalyst will also be determined. 

• Task 6 - Statistical Analysis. The experimental design for the project will be established to determine 

significant differences between engine-out and catalyst-out emission levels and characteristics for each 

test cycle on the test fuel.

Accomplishments

• Final test fuel obtained that meets 2007 federal specification of 15 ppm sulfur was obtained

• Experimental design has defined the number of replicates required for each test condition 

• Oven-aged test catalysts provided by Manufacturers of Emissions Controls Association (MECA)

• Catalysts stabilized by vehicle operation 

• Test vehicle (Mercedes Benz C220 CDI vehicle equipped with a diesel-powered 2.2 liter OM611 

engine) procured for the project

• Baseline emissions established and emissions testing on 2 catalysts completed

• Basic PM characterization conducted on baseline catalysts and first two test catalysts

Future Directions

• Conduct emissions tests on third catalyst (highest metal loading) 

• Conduct chemical analyses on exhaust samples

Introduction

Today's advanced technology diesel engines 

typically include four valves per cylinder, common 

rail injection, and turbocharging. However, diesel 

engines have a disadvantage of higher particulate 

emissions compared to gasoline engines. In addition, 

these particulates may contain unburned fuel species 

or products of combustion, which are undergoing 

scrutiny as potential air toxics. Diesel exhaust also 

contains gaseous hydrocarbon species that may be 

potential air toxics.

To reduce particulate emissions from diesel 

engines, aftertreatment manufacturers are developing 

several control technologies, including particulate 

filters, catalytic traps, and oxidation catalysts. In 

addition, technologies employing plasma and 

microwave techniques are being explored. These 

technologies have the potential to not only reduce the 

particulate mass loading, but also to alter the other 

characteristics of diesel exhaust. For example, an 

oxidation catalyst may be effective in oxidizing or 

reducing some of the gaseous organics in the exhaust 

or the liquid organic species deposited on the 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

42

particulate. Therefore, these particulate control 

devices may beneficially alter the overall emissions 

characteristics of the diesel vehicle.

Approach

This project is being conducted with 

collaborative funding and technical support from the 

Advanced Vehicle Fuel Lubricant (AVFL) 

Committee of Coordinating Research Council, Inc. 

(CRC). MECA is providing in-kind technical 

services and catalyst materials to support the work. 

The National Renewable Energy Laboratory is 

coordinating specification and acquisition of the test 

fuel and selection of the catalysts in concert with 

other related DOE research projects. The 

experimental program is being conducted through a 

contract with Southwest Research Institute (SwRI) in 

their Department of Emissions Research. 

The detailed approach for accomplishing the 

project objectives is described in the corresponding 

section above. The emission sampling system used 

by SwRI is depicted in Figure 1. The test vehicle is 

illustrated in Figure 2. A sample of the installed test 

catalyst configuration is shown in Figure 3. 

Conclusions

At the time of this report the test program results 

are considered preliminary and summary conclusions 

have not been defined.

Figure 2. Mercedes Benz C220 CDI Vehicle 

Equipped with a 2.2L OM611 DieselPowered Engine

Figure 1. Sampling System for DOC Emissions 

Characterization

Figure 3. Installed Diesel Oxidation Catalyst 

Configuration
Fuels for Advanced CIDI Engines FY 2002 Progress Report

43

IV. VEHICLE TEST AND EVALUATION

A. The Emissions Impacts of Various Fuels on a CIDI Vehicle

Edwin A. Frame (Primary Contact) 

Southwest Research Institute

6220 Culebra Road

San Antonio, TX 78238-5166

(210) 522-2515, fax: (210) 522-3270, e-mail: eframe@swri.edu

DOE Technology Development Manager: John Garbak 

(202) 585-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects on Exhaust Emission Control System Technology

E. Toxic Emissions

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objective

• Quantify the effects of advanced petroleum fuel oxygenate blends on the emissions of a vehicle 

powered by a state-of-the-art CIDI engine (OM611).

Approach

• Six fuels will be evaluated for tailpipe exhaust emissions from a European Mercedes Benz C220D 

series vehicle following the chassis dynamometer portion of the Federal Test Procedure (FTP) and the 

US06 aggressive driving cycles. 

Accomplishments

• The matrix of test fuels was approved by the U.S. Department of Energy. It includes advanced 

oxygenate blends, advanced fuel containing ethanol, and a fuel blend containing water.

• Testing was delayed pending the availability of a special base fuel that is a refinery produced prototype 

of 2007 U.S. ultra-low-sulfur diesel fuel.

Future Directions

• Evaluate the effects of fuel blends containing oxygenated materials in an advanced CIDI-powered 

vehicle that has advanced emission control devices such as NOx adsorption and diesel particulate filter 

technologies.

Introduction

Exhaust emission reductions have been 

demonstrated in many previous studies using 

alternative and reformulated diesel fuels. In previous 

investigations related to this project, exhaust 

emissions were determined in a Mercedes Benz "C" 

Series European vehicle (C220D) for a series of 

advanced petroleum-based fuels. The vehicle is 

powered by the OM611 engine, which has a 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

44

displacement of 2.2L and the following 

characteristics: direct-injection, four valves per 

cylinder, turbocharging and intercooling, highpressure common rail fuel injection system with pilot 

injection, exhaust gas recirculation, and intake port 

cut-off. According to the vehicle manufacturer, the 

emission control system of the C220D vehicle 

includes one catalytic converter close to the engine 

with a volume of 2.1 L, and an additional underbody 

catalytic converter with a volume of 1.8 L. Both 

converters have a platinum coating on a zeolite 

substrate and provide oxidation of hydrocarbons and 

CO with a slight reduction in NOx (i.e., a "lean-NOx" 

catalyst). The converter closest to the engine has an 

internal by-pass so that the underbody converter is 

supplied with hydrocarbons to assist in an additional 

slight reduction in NOx. Figure 1 is a photograph of 

the Mercedes Benz C220D vehicle.

In the previous investigations, none of the fuels 

tested in the C220D vehicle allowed it to meet EPA 

Tier 2 exhaust emission standards (note: this vehicle 

was not designed to meet the EPA Tier 2 standards). 

With respect to test cycle severity, the US06 was the 

most severe, followed by the FTP and then the 

European cycles. Overall, the results showed the 

benefit in PM reduction for the oxygenated fuel over 

the FTP and European cycles. No statistically 

significant emissions reductions were observed over 

the US06 aggressive driving cycle. The fuel blend 

containing 15% di-methyl maleate (DMM) 

consistently produced the lowest PM emissions; 

however, a slight increase in NOx was observed. 

DMM15 fuel consistently had the lowest levels of 

volatile organic fraction (VOF). Fuel economy for 

the DMM15 fuel ranged from 8 to 11% less than the 

baseline fuel (2D).

Approach

This project will include exhaust emission 

evaluations of a Mercedes-Benz C220D equipped 

with the OM611 engine. This four-valve-percylinder engine is turbocharged and intercooled, and 

includes a high pressure, common rail fuel injection 

system, exhaust gas recirculation, pilot injection and 

intake port cut-off. This vehicle is equipped with 

"lean-NOx" catalyst technology, which relies on lowsulfur fuel to be effective. The vehicle will be tested 

using the following six fuels:

• BP15 Fuel (prototype 2007 U.S. ultra-lowsulfur diesel fuel)

• BP15 Fuel + tripropylene glycol 

monomethyl ether (TPGME) @ 7% oxygen

• BP15 Fuel + TPGME @ 3.5% oxygen

• BP15 Fuel + di-butyl maleate @ 7% oxygen

• BP15 Fuel + 10% ethanol 

• BP15 Fuel based water emulsion 

All six fuels will be evaluated over the chassis 

dynamometer portion of the Federal Test Procedure 

(FTP) and the US06 aggressive driving cycles. All 

test cycles will be conducted in triplicate.

Testing will utilize a Horiba 48-inch single-roll 

chassis dynamometer. This dynamometer 

electrically simulates inertia weights up to 12,000 

pounds over the FTP-75 (up to 7,000 pounds for 

vehicles capable of following the US06 driving 

trace), and provides programmable road load 

simulation of up to 125 hp continuous at 65 mph 

(300-hp momentary duty at 65 mph). Southwest 

Research Institute (SwRI) will use a Mears Model to 

calculate a road load curve for the vehicle. This 

model requires coastdown data from drive and nondrive axles. A total of three coastdowns will be 

conducted on each axle, and the average results will 

be used as input for the Mears Model. The resulting 

calculated road load curve coefficients will be 

entered as the target "a", "b", and "c" values for use 

during the Horiba Road Load Derivation routine. 

With this routine, coastdowns are conducted with the 

Figure 1. Mercedes Benz C220D 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

45

vehicle on the chassis dynamometer to determine 

appropriate chassis dynamometer load coefficient 

settings. Vehicle equivalent test weight will be the 

measured curb weight of the vehicle with a 40 

percent fuel fill plus 300 pounds.

Dilute exhaust emission sampling will utilize a 

positive displacement-type constant volume sampler 

(CVS). An 18-inch diameter by 16-ft. long stainless 

steel dilution tunnel will be used in conjunction with 

the CVS to maintain an average tunnel sampling 

zone temperature of 110oF, with the maximum 

temperature not to exceed 125oF during the standard 

Federal Test Procedure. Nominal CVS flow rate will 

be 600 cubic feet per minute (cfm). A constantspeed cooling fan of 5,000 cfm capacity will be used 

in front of the vehicle during operation.

Regulated exhaust emissions (total 

hydrocarbons, carbon monoxide, oxides of nitrogen, 

and particulate matter) and carbon dioxide will be 

sampled and measured in a manner consistent with 

Environmental Protection Agency protocols for 

light-duty emission testing as given in the Code of 

Federal Regulations. Proportional dilute exhaust gas 

samples will be collected in Tedlar bags for analysis 

of carbon monoxide and carbon dioxide. Total 

hydrocarbons and oxides of nitrogen will be 

measured continuously from the dilution tunnel. 

Concurrently, a proportional sample of the dilute 

exhaust will be drawn through Pallflex T60A20 

fluorocarbon-coated glass fiber filters for 

determination of particulate matter. Filter samples 

will be analyzed by direct filter injection gas 

chromatography (DFI/GC) to determine the 

particulate VOF and lubricating oil contribution to 

VOF. Exhaust constituents will be analyzed as 

specified below:

Appropriate statistical techniques will be used to 

determine differences between the six fuels. 

Analysis of variance will determine whether the 

average response of the six fuels is statistically 

different. All comparison tests will be made at the 

5% level of significance.

Results

The project was delayed pending the availability 

of the BP15 Fuel. Testing will be completed in early 

2003.

Constituent Analysis Method

Total Hydrocarbon Heated Flame Ionization Detector

Carbon Monoxide Non-Dispersive InfraredAnalysis

Carbon Dioxide Non-Dispersive Infrared Analysis

Oxides of Nitrogen Chemiluminescent Analysis

Particulate Matter Gravimetric

Volatile Organic 

Fraction of PM

Direct Filter Injection Gas 

Chromatography

Oil Fraction of VOF Direct Filter Injection Gas 

Chromatography
Fuels for Advanced CIDI Engines FY 2002 Progress Report

46

B. EC-Diesel Technology Validation Project

Teresa L. Alleman (Primary Contact), Keith Vertin

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-4514, fax: (303) 275-4415, e-mail: Teresa_Alleman@nrel.gov

DOE Technology Development Manager: Stephen Goguen

(202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Subcontractors: West Virginia University, WV; Desert Research Institute, Reno, NV

This project addresses the following OTT R&D Plan barriers and tasks:

Barriers

B. Fuel Property Effects on Exhaust Emission Control System Technology

C. Emission Control System Degradation

E. Toxic Emissions

F. Ultra-fine Particles

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objectives

• Compare exhaust emissions from vehicles fueled with EC-Diesel (ECD) and California Air Resources 

Board (CARB) diesel fuels. 

• Evaluate the performance, emissions, and durability of the vehicles retrofitted with catalyzed particle 

filters and fueled with ECD over twelve or more months of service.

• Collect fuel consumption, maintenance, reliability, and operating cost data for the participating vehicle 

fleets and compare to control vehicles fueled with CARB diesel fuel.

• Chemically characterize the emissions from a select subset of vehicles in the fleets to compare the 

effects of ECD and ECD-1, with and without diesel particle filters, to CARB diesel fuel.

Approach

• Work with government-industry working group that was established in FY01 to select vehicle fleets 

for participation in the project.

• Design test matrix for regulated and unregulated emissions testing for the second round of vehicle tests 

in the winter of 2001.

• Compare first and second round of emissions test results.

• Objectively analyze vehicle performance and emissions data for both fuels, and draw conclusions.

• Objectively analyze the unregulated emissions results for the fuel and aftertreatment combinations, 

and draw conclusions.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

47

Accomplishments

• Second round test results were published in an SAE (Society of Automotive Engineers) technical 

paper (2002-01-0433). The results in the paper include emissions and vehicle performance data. A 

technical presentation was made at the 2002 SAE World Congress highlighting the results in the paper.

• A final data report documenting the detailed vehicle performance results from the Ralphs grocery fleet 

was published.

• Results from a portion of the chemical characterization, including particle sizing, inorganic ions and 

elements, benzene, light olefins, toluene, ethyl-benzene, xylene isomers (BTEX), and ethene data, 

have been published in an SAE technical paper (2002-01-0432) and presented at the 2002 SAE World 

Congress.

Future Directions

• Additional results, including polycyclic aromatic hydrocarbons (PAH), nitro-PAH (n-PAH), and 1,3-

butadiene, from the chemical characterization will be published in FY03. 

• Further testing is needed to examine the capabilities and limitations of passive diesel particle filters in 

colder climates and in older vehicles.

Introduction

ARCO, a BP company, has developed two new 

diesel fuels called Emission Control Diesel (ECD) 

and Emission Control Diesel-1 (ECD-1). Both fuels 

have sulfur contents of less than 15 ppm. The ECD 

fuel has an aromatics content of 10% and a cetane 

number of 60. The ECD-1 fuel, BP’s commercial 

product, has an aromatics content of 22% and a 

cetane number of 50.

Catalyzed diesel particle filters have been shown 

to operate more efficiently as diesel fuel sulfur 

content is decreased (1,2,3). Ultra-low sulfur diesel 

fuels expand the filter regeneration temperature 

window, improving particulate matter removal for a 

wide range of engine operating conditions. 

A one-year technology validation project was 

conducted to evaluate ECD and catalyzed diesel 

particle filters on diesel vehicle fleets in Southern 

California. The fuel’s performance, impact on 

engine durability and vehicle performance, and 

emission characteristics were evaluated and 

compared to conventional CARB diesel fuel. 

Several vehicles from the project were selected 

for detailed exhaust chemical characterization. The 

vehicles were operated on CARB and ultra-low 

sulfur diesel fuels, with and without diesel particle 

filters. The results from the exhaust characterization 

were compared, using the CARB diesel fuel as a 

normative baseline.

Approach

Seven Southern California heavy-duty diesel 

fleets were selected to participate in the ECD 

Technology Validation Project. The fleets contained 

a set of nominally identical vehicles that participated 

in the project. Within each fleet, a number of 

vehicles were selected as control vehicles fueled with 

CARB diesel fuel and no aftertreatment. Of the 

remaining vehicles, all were fueled exclusively with 

ECD for the twelve-month project. Several of the 

ECD-fueled vehicles were operated without 

aftertreatment. The final set of ECD fueled vehicles 

were retrofit with either Johnson Matthey’s 

Continuously Regenerating Technology (CRTTM) or 

Engelhard’s catalytic soot filter (DPXTM).

Both the DPX and CRT are passively regenerated diesel particle filters. The filters replaced 

the existing muffler. No engine modifications were 

made to the vehicles with the DPX or CRT filters.

Results 

Two rounds of emission testing were performed 

to evaluate the performance of the filters over the 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

48

twelve-month test period. The fleet vehicles 

operated in typical duty cycles throughout the 

performance period. The filters were not serviced 

between the first and second rounds of emissions 

testing. Emission test results showed the filters were 

effective at removing ~90% of the PM after twelve 

months of operation (4). 

The Ralphs grocery fleet was selected for 

evaluation of operating cost, maintenance, and fuel 

economy. Total operating costs were comparable for 

the fleet, regardless of fuel type or presence of 

aftertreatment (4). Twenty vehicles participated in 

the project, with five vehicles operated on CARB 

diesel fuel (control vehicles). The fifteen remaining 

vehicles were operated on ECD fuel. Five of the 

fifteen were operated without aftertreatment. Ten 

vehicles were retrofit with diesel particle filters, five 

each with the Johnson Matthey CRT and the 

Engelhard DPX. No difference was observed in the 

fuel economy for the vehicles operating with DPFs 

compared to the CARB diesel vehicles (Figure 1). 

One of the Ralphs grocery trucks was selected 

for exhaust chemical characterization. The 

particulate matter was collected with size selective 

cyclones to give a rough approximation of the size. 

The PM was divided into three categories – total 

particulate matter (TPM), PM10 (all PM less than 10 

μm), and PM2.5 (all PM less than 2.5 μm). Results 

show that the TPM, PM10, and PM2.5 emissions are 

similar for the CARB and ECD-1 fuels. The 

aftertreatment reduced the TPM, PM10, and PM2.5

emissions by ~90% (Figure 2). 

The ‘CARB’ and ‘ECD-1’ captions signify the 

grocery truck operating on CARB or ECD-1 diesel 

fuel without aftertreatment, respectively. The 

‘ECD+CRT’ and ‘ECD-1+CRT’ represent the 

grocery truck operating on ECD or ECD-1 fuel and 

retrofit with the CRT particle filter. 

Light olefins are important precursors for ozone 

formation. The CARB and ECD-1 diesel fuels 

without aftertreatment have similar emissions, while 

the CRT reduced the emissions by ~80% (Figure 3).

Figure 1. Average Fuel Economy for Grocery Trucks 

with and without Diesel Particle Filters

Figure 2. TPM, PM10, and PM2.5 Emissions from a 

Grocery Truck Operating on CARB and ECD-1 

without Aftertreatment, and ECD and ECD-1 

with CRT

Figure 3. Light Olefin Emissions from a Grocery Truck 

Operating on CARB and ECD-1 without 

Aftertreatment, and ECD and ECD-1 with CRT
Fuels for Advanced CIDI Engines FY 2002 Progress Report

49

Conclusions

Several heavy-duty diesel fleets have been 

retrofitted with diesel particle filters. Two rounds of 

emissions testing have been completed showing that 

the filters are effective at removing PM, HC, and CO 

emissions after twelve months of continuous use. 

Vehicles operating on the filters did not have a 

significant fuel economy penalty, compared to 

vehicles operating on conventional diesel fuel. The 

filters were effective at reducing unregulated 

emissions, such as PM10, PM2.5, and light olefins. 

References

1. U.S. Department of Energy, Engine 

Manufacturers Association, and Manufacturers of 

Emission Controls Association, “Diesel 

Emissions Control – Sulfur Effects (DECSE) 

Program, Phase I Interim Data Report No. 4: 

Diesel Particulate Filters Final Report”, http://

www.ott.doe.gov/decse, Jan. 2000.

2. Warren, J., Allansson, R., Hawer, P., Wilkins, A., 

“Effects of After-Treatment on Particulate Matter 

when Using the Continuously Regenerative Trap 

(CRTTM)”, IMechE Technical Paper S491/006/98, 

1998.

3. Cooper, B., Thoss, J., “Role of NO in Diesel 

Particulate Control”, SAE Technical Paper No. 

890404, 1989.

4. LeTavec, C., Uihlein, J., Vertin, K., Chatterjee, S., 

Wayne, S., Clark, N., Gautam, M., Thompson, G., 

Lyons, D., Hallstrom, K., Chandler, K., Coburn, 

T., “Year-Long Evaluation of Trucks and Buses 

Equipped with Passive Diesel Particulate Filters”, 

SAE Technical Paper No. 2002-01-0433, 2002.

Publications

1. LeTavec, C., Uihlein, J., Vertin, K., Chatterjee, S., 

Wayne, S., Clark, N., Gautam, M., Thompson, G., 

Lyons, D., Hallstrom, K., Chandler, K., Coburn, 

T., “Year-Long Evaluation of Trucks and Buses 

Equipped with Passive Diesel Particulate Filters”, 

SAE Technical Paper No. 2002-01-0433, 2002.

2. Lev-On, M., LeTavec, C., Uihlein, J., Alleman, T., 

Lawson, D., Vertin, K., Thompson, G., Gautam, 

M., Wayne, S., Zielinska, B., Sagebiel, J., 

“Chemical Speciation of Exhaust Emissions from 

Trucks and Buses Fueled on Ultra-Low Sulfur 

Diesel and CNG”, SAE Technical Paper No. 

2002-01-0432, 2002.

3. Battelle, 2001, “Ralphs Grocery EC-Diesel Truck 

Fleet Final Data Report”, Columbus, OH.

4. Zielinska, B., Sagebiel, J., Lev-On, M., LeTavec, 

C., Alleman, T., Lawson, D., Vertin, K., 

Thompson, G., Gautam, M., Wayne, S., Okamoto, 

R., “Chemical Characterization of Exhaust 

Emissions from Heavy-Duty Vehicles Fueled by 

Ultra-Low Sulfur Fuel and Equipped with Particle 

Filters”, A&WMA Proceedings, 2002.

Presentations

1. Vertin, K., “Year-Long Evaluation of Trucks and 

Buses Equipped with Passive Diesel Particulate 

Filters”, presented at SAE 2002 World Congress, 

March 4-7, 2002.

2. Lev-On, M., “Chemical Speciation of Exhaust 

Emissions from Trucks and Buses Fueled on 

Ultra-Low Sulfur Diesel and CNG”, presented at 

SAE 2002 World Congress, March 4-7, 2002.

3. Zielinska, B., “Chemical Characterization of 

Exhaust Emissions from Heavy-Duty Diesel 

Vehicles Using Low Sulfur Fuel and Equipped 

with Particle Filters”, presented at 12th CRC OnRoad Vehicle Emissions Workshop, April 15-17, 

2002.

4. Zielinska, B., “Chemical Characterization of 

Exhaust Emissions from Heavy-Duty Vehicles 

Fueled by Ultra-Low Sulfur Fuel and Equipped 

with Particle Filters”, Air & Waste Management 

Association 95th Annual Meeting and Exhibition, 

Baltimore, MD, June 23-27, 2002.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

50

V. SUPPORTING RESEARCH

A. Investigation of the Combustion and Soot-Formation Characteristics of 

Oxygenated Diesel Fuels

Chuck Mueller (Primary Contact), Glen Martin, Dennis Siebers, Lyle Pickett

Sandia National Laboratories

7011 East Ave., MS 9053

Livermore, CA 94550-9517

(925) 294-2223, fax: (925) 294-1004, e-mail: cjmuell@sandia.gov

Bruce Buchholz

Lawrence Livermore National Laboratory

P.O. Box 808, CAMS L-397

Livermore, CA 94550-9900

DOE Technology Development Managers: 

Stephen Goguen: (202) 586-8044, fax: (202) 586-1600, e-mail: Stephen.Goguen@ee.doe.gov

Gurpreet Singh: (202) 586-2333, fax: (202) 586-4166, e-mail: Gurpreet.Singh@ee.doe.gov

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Kevin Stork: (202) 586-8306, fax: (202) 586-4166, e-mail: Kevin.Stork@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

A. Fuel Property Effects on Engine Emissions and Efficiency

F. Ultra-fine Particles

Tasks

2. Fuel & Lubrication Properties - Engine-Out Emissions

Objectives

• Enhance fundamental understanding of how diesel fuel oxygenates affect mixing, combustion, and 

emissions-formation processes within the engine cylinder. 

• Determine why some oxygenates are better than others at reducing particulate matter emissions from 

compression ignition direct injection (CIDI) engines.

• Use new knowledge to help identify a "short list" of oxygenate molecules that show particular promise 

for delivering excellent engine performance with minimal emissions.

• Feed back new fundamental knowledge to engine manufacturers, fuel suppliers, and other stakeholders 

so that engine design and fuel formulation can be used together in an optimal manner to meet future 

emissions and efficiency goals.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

51

Approach

• Task 1 Complete detailed natural luminosity (NL) imaging study of combustion of two oxygenated 

fuels and one reference fuel in Sandia/Caterpillar Optical Research Engine (SCORE) laboratory. Fuels 

are formulated such that oxygenate molecular structure is the only significant difference between two 

oxygenated fuels; other properties such as oxygen content, combustion phasing, operating conditions, 

and adiabatic flame temperature are explicitly matched. Oxygenates under study are di-butyl maleate 

(DBM) and tri-propylene glycol methyl ether (TPGME).

• Task 2 Derive a mathematical relationship between NL signal and soot concentration at a point within 

the engine cylinder.

• Task 3 Use mathematical relationship developed in Task 2 along with known properties of soot, fuels, 

and imaging system to determine whether spatially integrated natural luminosity (SINL) can be used to 

rank oxygenates based on their ability to reduce in-cylinder soot concentrations.

• Task 4 Verify results from Tasks 1-3 with laser-induced incandescence (LII) measurements in the 

Diesel Combustion Simulation Facility (DCSF).

• Task 5 Attempt to determine reasons why one oxygenated test fuel produces significantly more soot 

than another, even when all other variables are matched.

• Task 6 Initiate and demonstrate accelerator mass spectrometry (AMS) measurement capabilities in the 

SCORE laboratory. Obtain information about chemical-kinetic pathways underlying enhanced sootreduction potential of one oxygenated fuel relative to another.

• Task 7 Analyze results and report findings to collaborators in industry, academia, and national 

laboratories. Publish in open literature to broadly disseminate results and conclusions.

 Accomplishments

• Completed all tasks. Some highlights: 

- Quantified relationship between NL signal and local soot volume fraction.

- Conducted detailed analysis to show that, under the present conditions, peak SINL can be used as a 

conservative method to rank the test fuels based on their ability to reduce the average in-cylinder 

soot volume fraction.

- Discovered that fuel containing TPGME oxygenate was significantly more effective at reducing incylinder soot than fuel containing DBM oxygenate.

- Found that both oxygenated fuels significantly reduce in-cylinder soot relative to the nonoxygenated reference fuel.

- Observed same rank-ordering of test fuels in LII imaging experiments conducted in DCSF.

- Measured flame lift-off lengths in DCSF to show that differences in air entrainment are not large 

enough to account for observed differences in soot production between the oxygenated fuels.

- Conducted a double-distillation analysis of DBM oxygenate to reveal evidence of polymerization 

and/or thermal decomposition before complete vaporization. This finding may help account for its 

relatively higher soot production and may provide a warning sign for injector deposit formation 

problems with the DBM oxygenate.

- Added capability to use AMS diagnostics in SCORE laboratory to track carbon atoms in specific 

bond positions from the fuel molecule, through the combustion event, to particulate and gaseous 

emissions.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

52

Future Directions

• Measure test fuel lift-off lengths in optical engine and compare to results from DCSF. Multiple-jet and 

jet-wall interactions that are absent in DCSF may be important in engine.

• Measure test fuel soot distributions in DCSF using a quantitative laser-extinction diagnostic. Fuelbound oxygen may be more effective at reducing soot than oxygen entrained from charge air.

• Continue AMS experiments with oxygenates and expand scope to include other fuel constituent 

molecules. Results will help identify links between fuel molecular structure and particulate/gaseous 

emissions from CIDI engines.

• Initiate development of in-cylinder NOx measurement capabilities to study combined effects of fuels 

and operating conditions on NOx evolution. 

Introduction

Blending oxygen-containing compounds 

("oxygenates") with diesel fuel can lead to reduced 

soot and nitrogen oxides (NOx) emissions, as well as 

reduced fuel consumption. The detailed mechanisms 

that cause such reductions are not well understood. 

This project is focused on understanding why certain 

oxygenates are better than others at reducing the 

amount of soot produced by CIDI engines. 

Approach

The SCORE laboratory shown in Figure 1 

features a single-cylinder version of a moderntechnology, Caterpillar 4-stroke DI diesel engine that 

has been modified by Sandia to provide extensive 

optical access into the combustion chamber [1]. The 

optical engine is based on the Caterpillar C-10 

platform used in heavy-duty trucking. A schematic 

of the optical engine is shown in Figure 2. The large 

window in the piston bowl enables combustion 

processes within the engine to be imaged during 

operation. Specifications of the optical engine are 

provided in Table 1. 

In-cylinder images of NL and spray development 

were acquired and coupled with measurements of 

cylinder pressure and injected fuel quantity. The NL 

image sequences show the evolution of regions of 

high soot concentration and temperature throughout 

the combustion event. The spray-development 

images provide verification that the experimental 

fuels do not degrade fuel-injection system 

performance over time. The cylinder pressure and 

injected quantity measurements provide information 

about heat-release rates and engine efficiency, 

respectively.

Three test fuels were formulated for this work: 

one non-oxygenated reference fuel (denoted CN80) 

and two oxygenated fuels. Overall oxygen content 

was matched for the two oxygenated test fuels. The 

two oxygenate molecules used were those identified 

as having the best potential for blending with diesel 

fuel by the DOE Oxygenate Analysis Project [2,3]. 

The first oxygenated fuel (denoted BM88) contains 

the oxygenate DBM; the second (denoted GE80) 

contains the oxygenate TPGME. Compositional 

information for the test fuels is provided in Table 2, 

and the oxygenate molecular structures are shown in 

Figure 3. 

Table 1. Specifications of the Sandia/Caterpillar Optical 

Research Engine

Production engine type 6-cyl. Caterpillar C-10

Research engine type 1-cyl. version of C-10

Cycle 4-stroke CIDI

Valves per cylinder 4

Ignition assist (not used) In-cylinder glow plug

Bore 125 mm

Stroke 140 mm

Peak cylinder pressure 14.0 MPa

Intake valve open 32° BTDC exhaust

Intake valve close 153° BTDC compression

Exhaust valve open 116° ATDC compression

Exhaust valve close 11° ATDC exhaust

Connecting rod length 225 mm

Connecting rod offset None

Bowl diameter 90 mm

Bowl depth 16.4 mm

Swirl ratio 0.59

Displacement per cyl. 1.72 liters

Compression ratio* 11.3:1

Simulated compr. ratio 16.0:1

*TDC temperature, density, and pressure in the 

production engine are matched in the optical engine by 

preheating and boosting the pressure of the intake air.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

53

Figure 1. Sandia/Caterpillar Optical Research 

Engine (SCORE) Laboratory in operation.

Figure 2. Schematic diagram of the SCORE. Inset: 

View of combustion chamber showing 

orientation of fuel sprays with respect to 

glow plug (note glow plug not energized 

during these experiments).

Table 2. Test Fuel Compositions

Fuel Composition 

(by volume)

Oxygen Content

(by weight)

CN80 76.5% C16H34 as NHDa

23.5% C16H34 as HMNb

0%

BM88 88.0% DBMc

7.0% C16H34 as NHDa

5.0% EHNd

26.5%

GE80 80.0% TPGMEe

20.0% C16H34 as HMNb

25.8%

a n-hexadecane

b 2,2,4,4,6,8,8-heptamethylnonane

c di-butyl maleate

d 2-ethylhexyl nitrate

e tri-propylene glycol methyl ether

Figure 3. Molecular structures of oxygenate molecules. 

Dark and light circles represent carbon and 

oxygen atoms, respectively. Hydrogen atoms 

omitted for clarity. a. Di-butyl maleate 

(DBM). b. Tri-propylene glycol methyl 

ether (TPGME).
Fuels for Advanced CIDI Engines FY 2002 Progress Report

54

Results and Conclusions

Previous research conducted in the SCORE 

laboratory suggested that overall oxygen content is 

not the only important parameter governing the sootreduction performance of an oxygenated fuel. 

Research conducted this year has extended our 

understanding by establishing that oxygenate 

molecular structure can play a very important role in 

soot reduction, especially for highly oxygenated 

fuels. 

One of this year's first tasks was to conduct a 

detailed mathematical and physical analysis to 

determine the validity of using SINL as a means to 

estimate in-cylinder soot concentrations. The 

analysis showed that comparing peak SINL values 

provides a conservative method for estimating the 

soot-reduction potential of the test fuels under the 

present operating conditions [4]. Figure 4 shows 

peak SINL values achieved during combustion of the 

test fuels in this work [4], along with a data point for 

neat methanol (M100) from Reference [1]. It is 

evident that the relative amount of soot produced 

decreases as the oxygen content of the fuel increases. 

The shaded region in Figure 4 delineates an envelope 

of results from other studies that have shown that 

computed soot precursor concentrations and engineout smoke emissions go to zero when the oxygen 

content in the fuel reaches 30-40% [5,6]. Note that 

the data points for BM88 and GE80 are at the high 

and low ends of this region, respectively, suggesting 

that TPGME is considerably more effective at 

reducing soot than DBM.

Figure 5 shows LII images that were acquired in 

the constant-volume Diesel Combustion simulation 

Facility (DCSF) at conditions matched to those in the 

optical engine. They yield the same trend as the 

SINL results, namely that BM88 produces 

significantly more in-cylinder soot than GE80. 

Why would one oxygenated fuel be more 

effective at reducing soot than another, even when 

their oxygen content, combustion phasing, adiabatic 

flame temperature, and all engine operating 

conditions are matched? Two possible explanations 

are differences in air entrainment and differences in 

molecular-structure/chemical characteristics of the 

fuels.

One important parameter affecting air 

entrainment is the distance a diesel flame stands off 

from the injector orifice, i.e., the lift-off length [7]. 

The longer the lift-off length, the more air can be 

mixed into the fuel-rich core of the diesel spray 

before combustion begins, and the less soot is 

produced. Figure 6 shows flame lift-off lengths 

measured for the two oxygenated fuels in the DCSF. 

While the lift-off lengths are slightly different, 

analysis has shown that this factor alone cannot 

Figure 4. Variation of spatially integrated natural 

luminosity (SINL) for the test fuels as a 

function of fuel oxygen content. 

Figure 5. Laser-induced incandescence (LII) images 

for a. BM88 and b. GE80 fuels. Injector 

orifice located at center of left edge of 

image. Width of imaged region is 95 mm. 

Camera gain provided in lower-right 

corner of image (lower gain = larger 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

55

account for the large disparity between in-cylinder 

soot concentrations. 

It is not surprising that molecular-structure/

chemical effects could cause the observed difference 

in soot between the two oxygenated fuels. After all, 

great effort was expended to vary only the type of 

oxygenate molecule in the experiments. One 

chemical effect was discovered by conducting a 

double-distillation analysis of DBM, which showed 

evidence of 5-10% polymerization and thermal 

decomposition before complete vaporization. This 

phenomenon was not observed for either of the other 

test fuels. It could lead to increased soot production 

as well as deposit formation in injector tips, and may 

preclude further consideration of DBM as a viable 

diesel oxygenate. Furthermore, chemical-kinetic 

analyses indicate that DBM is more likely to produce 

soot precursors during oxidation than TPGME [8]. 

Experiments using AMS diagnostics are currently 

underway in the SCORE laboratory to test this 

hypothesis [9] and to identify improved oxygenate 

molecules.

References

1. Mueller, C.J. and Musculus, M.P., "Glow Plug 

Assisted Ignition and Combustion of Methanol in 

an Optical DI Diesel Engine," SAE Paper 2001-

01-2004.

2. Natarajan, M., Frame, E., Naegeli, D.W., Asmus, 

T., Clark, W., Garbak, J., Gonzalez, M.A., Liney, 

E., Piel, W., and Wallace, J.P., "Oxygenates for 

Advanced Petroleum-Based Diesel Fuels: Part 1. 

Screening and Selection Methodology for the 

Oxygenates," SAE Paper 2001-01-3631.

3. Gonzalez, M.A., Piel, W., Asmus, T., Clark, W., 

Garbak, J., Liney, E., Natarajan, M., Naegeli, 

D.W., Yost, D., Frame, E., and Wallace, J.P., 

"Oxygenates Screening for Advanced PetroleumBased Diesel Fuels: Part 2. The Effect of 

Oxygenate Blending Compounds on Exhaust 

Emissions," SAE Paper 2001-01-3632.

4. Mueller, C.J. and Martin, G.C., "Effects of 

Oxygenated Compounds on Combustion and Soot 

Evolution in a DI Diesel Engine: Broadband 

Natural Luminosity Imaging," SAE Paper 2002-

01-1631.

5. Miyamoto, N., Ogawa, H., Nurun, N., Obata, K., 

and Arima, T., "Smokeless, Low NOx, High 

Thermal Efficiency, and Low Noise Diesel 

Combustion with Oxygenated Agents as Main 

Fuel," SAE Paper 980506.

6. Curran, H.J., Fisher, E.M., Glaude, P.A., Marinov, 

N.M., Pitz, W.J., Westbrook, C.K., Layton, D.W., 

Flynn, P.F., Durrett, R.P., zur Loye, A.O., 

Akinyemi, O.C., and Dryer, F.L., "Detailed 

Chemical Kinetic Modeling of Diesel Combustion 

with Oxygenated Fuels," SAE Paper 2001-01-

0653.

7. Siebers, D.L. and Higgins, B.S., "Flame Lift-Off 

on Direct-Injection Diesel Sprays Under 

Quiescent Conditions," SAE Paper 2001-01-0530.

8. Westbrook, C.K., "The Impact of Oxygenated 

Blending Compounds on PM and NOx Formation 

of Diesel Fuel Blends," Proc. of CIDI Engine 

Combustion, Emission Control, and Fuels 

Figure 6. Lift-off length images for a. BM88 and b. 

GE80 fuels. Injector orifice located at center 

of left edge of image. Width of imaged 

region is 40 mm. Difference in lift-off length 

is not sufficient to account for difference in 

amount of soot produced.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

56

Program Review, Argonne National Laboratory, 

Argonne, IL (2002).

9. Buchholz, B.A., "Isotopic Tracing of Fuel 

Components in Particulate Emissions from Diesel 

Engines using Accelerator Mass Spectrometry," 

Proc. of CIDI Engine Combustion, Emission 

Control, and Fuels Program Review, Argonne 

National Laboratory, Argonne, IL (2002).

FY 2002 Award

1. Mueller, C.J. and Musculus, M.P., "Glow Plug 

Assisted Ignition and Combustion of Methanol in 

an Optical DI Diesel Engine," SAE Paper 2001-

01-2004, Society of Automotive Engineers, 

Warrendale, PA (2001).

FY 2002 Publications and Presentations

1. Mueller, C.J. and Martin, G.C., "Effects of 

Oxygenated Compounds on Combustion and 

Soot Evolution in a DI Diesel Engine: Broadband 

Natural Luminosity Imaging," SAE Paper 2002-

01-1631.

2. Buchholz, B.A, Cheng, A.S., Dibble, R.W., 

Mueller, C.J., and Martin, G.C., "Isotopic Tracing 

of Fuel Component Carbon in the Emissions 

from Diesel Engines," SAE Paper 2002-01-1942.

3. Mueller, C.J., "Effects of Oxygenated Diesel 

Fuels on In-Cylinder Combustion and SootFormation Processes," Proc. of CIDI Engine 

Combustion, Emission Control, and Fuels 

Program Review, Oak Ridge National 

Laboratory, Oak Ridge, TN (2001). 

4. "Oxygenated Diesel Fuel Research at Sandia 

National Laboratories," PDVSA/Citgo 

Transportation Panel Meeting, Tulsa, OK (June 

20, 2002).

5. "Accelerator Mass Spectrometry: A New Tool for 

Studying Diesel Emissions Formation," Joint 

Heavy-Duty/Alternative Fuels Diesel 

Combustion CRADA Meeting, Detroit, MI (June 

13, 2002).

6. "Oxygenated Diesel Fuel Research at Sandia 

National Laboratories," DOE Office of 

Transportation Technologies Annual Program 

Review, Argonne, IL (May 15, 2002).

7. "Effects of Oxygenated Compounds on 

Combustion and Soot Evolution in a DI Diesel 

Engine: Broadband Natural Luminosity 

Imaging," SAE Spring 2002 Fuels and Lubricants 

Meeting, Reno, NV (May 6, 2002).

8. "Oxygenated Diesel Fuel Research at Sandia 

National Laboratories," DOE Office of 

Transportation Technologies Mid-Year Program 

Review, Livermore, CA (March 27, 2002).

9. "Natural Luminosity Signal Interpretation," Joint 

Heavy-Duty/Alternative Fuels Diesel 

Combustion CRADA Meeting, Livermore, CA 

(January 17, 2002).

10. "Effects of Oxygenated Diesel Fuels on InCylinder Combustion and Soot-Formation 

Processes," 7th Diesel Engine Emissions 

Reduction Workshop, Portsmouth, VA (August 6, 

2001).

11. "Isotopic Tracing by Accelerator Mass 

Spectrometry Shows Fate of Tagged Diesel Fuel 

Oxygenate," CRF News 24: 2 (2002).

12. "Climbing the Emissions Performance Mountain: 

Oxygen Helps," DOE Office of Heavy Vehicle 

Technologies web site at http://

www.trucks.doe.gov/research/fuel/oxygen.html 

(2002).
Fuels for Advanced CIDI Engines FY 2002 Progress Report

57

B. Chemical Characterization of Toxicologically Relevant Compounds from 

Diesel Emissions: A Project of the Fuels/Particulate Matter Initiative; Phase I & 

II

Douglas M. Yost (Primary Contact), Edwin A. Frame, Ed C. Owens

Southwest Research Institute

6220 Culebra Road

San Antonio, TX 78238-5166

(210) 522-3126, fax: (210) 522-3270, e-mail: dyost@swri.org

DOE Technology Development Manager: John Garbak

(202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

E. Toxic Emissions

Tasks

2. Fuel & Lubricant Properties - Engine-Out Emissions

Objectives

• Investigate the role of fuels on tailpipe exhaust emissions of potentially toxicologically relevant 

compounds, utilizing a diesel oxidation catalyst and a catalyzed particulate filter.

• Investigate low-NOx engine operation effects on diesel exhaust emission toxicity.

• Investigate role of high moleculer weight oxygenate on diesel exhaust toxicity.

• Determine polycyclic aromatic hydrocarbon (PAH) content of organic solvent extracts of exhaust 

particulate matter, gaseous exhaust PAH, and other gaseous exhaust "toxics" collected from a diesel 

engine using various fuel compositions.

Approach

• A Daimler-Benz OM611 diesel engine was used to determine the effect of diesel fuel type on 

toxicologically relevant compounds from engine-out exhaust emissions.

• Engine was controlled by SwRI Rapid Prototyping Electronic Control System (RPECS).

• Test matrix to include seven fuels, including two oxygenate blends with tripropylene glycol 

monomethyl ether (TPGME) and one oxygenate blend with dibutyl maleate (DBM), operated over 

four speed/load points.

• Engine to be operated utilizing pilot fuel injection at a low-NOx engine-out calibration specific for 

each fuel and speed/load point.

• Measurements to be taken at engine-out, after the diesel oxidation catalyst, and after the catalyzed 

particulate filter. 

Accomplishments

• Project plan was fully coordinated with DOE and industry. Industry defined NOx emission index 

targets.

• Industry was consulted to define a methodology to achieve low engine-out NOx emission index target.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

58

• Engine-out NOx emission index reduction of 45% is achievable from stock engine modal calibrations.

Future Directions

• Determine fuel effects on emission characterization utilizing a NOx trap.

• Determine fuel effects on emission characterization with NOx and particulate trap regeneration. 

• Determine fuel effects on emission characterization for premixed charge compression ignition 

combustion.

Introduction

The Particulate Matter (PM) Analysis Phase II 

project is part of an overall study that examines the 

effect of oxygenated compounds in diesel fuel on the 

emissions of particulate matter, oxides of nitrogen, 

and fuel economy when emission control devices are 

used. The project will focus on the chemical 

characterization of emissions of compounds with 

known or suspected toxicological properties. 

Exhaust emissions of these compounds will be 

measured before and after emission control devices 

to better understand the effects of emission control 

devices and alternative fuels. 

Objective

The control of NOx emissions is probably the 

greatest technical challenge in meeting future 

emission regulations for diesel engines. In this 

project, lowering engine-out emissions of NOx by 

increasing exhaust gas recirculation (EGR) and 

retarding timing will likely cause an increase in PM 

emissions. In Phase I of this project, it was shown 

that the use of an oxygenated diesel fuel additive will 

lower PM emissions. Use of an oxygenated diesel 

fuel additive thereby can minimize the increase in 

PM emissions that accompany the techniques used to 

decrease NOx emissions. 

The overall objective of this project is to better 

understand the role of fuels and emission control 

devices on the exhaust emissions of a subset of 

potentially toxicologically relevant compounds with 

an engine operated to minimize NOx emissions. The 

three objectives of this project are to measure the 

following pollutants collected from diesel engines 

under a matrix of engine and fuel conditions:

• Polycyclic aromatic hydrocarbon (PAH) 

content of organic solvent extracts of 

particulate matter

• Gas phase polycyclic aromatic hydrocarbons

• Gaseous toxic compounds (formaldehyde, 

acetaldehyde, benzene and 1,3-butadiene)

These measurements will be made on engine-out 

exhaust emissions, and after an oxidation catalyst 

and a diesel particulate filter. 

Approach and Results

PM Analysis II Emission Control System Selection

Discussions were held with Manufacturers of 

Emission Controls Association (MECA) to specify 

component configurations for the diesel oxidation 

catalyst and the diesel particulate filter. The 

component configurations that were selected are a 

1.5L diesel oxidation catalyst and a 2.5L catalyzed 

wall flow particulate filter. The soot loading capacity 

of the particulate filter is a nominal 17 grams. It was 

mentioned that the catalyst “wake-up” temperature 

range, 170°C-200°C, may be of significant interest 

for typical light-duty diesel operation. Exploratory 

engine operation at 1250 and 1500-rpm (1.0 bar- barbrake mean effective pressure [bmep]) were 

evaluated to obtain exhaust stack temperatures; at the 

original equipment manufacturer (OEM) calibration 

condition, exhaust stack temperature was around 

167°C at 1250 rpm, and around 179°C at 1500 rpm. 

Exploratory runs at a Low-NOx operating condition 

with increased EGR and retarded timing increased 

the exhaust stack temperature at 1500-rpm (1.0 

bmep) to 195°C. The Ad Hoc CIDI fuels working 

group agreed that a mode at the catalyst “wake-up” 

temperature, defined as Mode 22, 1500-rpm (1.0 barbmep), would be used in the test project.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

59

The MECA supplier for the emission control 

devices coated, canned, baked, and delivered the 

devices to SwRI. The MECA supplier baked the 

aftertreatment devices in a 600°C oven for 48 hours 

prior to delivery. The baking was performed to degas 

the insulation, packing, and washcoat. The baking 

will reduce the time required to degreen the devices 

on the engine. A 1.5L diesel oxidation catalyst 

(DOC) and a 2.5L catalyzed diesel particulate filter 

(DPF) were received and installed in the OM611 

engine test cell. 

The OM611 engine was operated with both 

emission control devices (ECDs) present to 

determine the effect of the ECDs on backpressure 

and engine control. The engine-out backpressure 

was higher with the ECDs installed; however, control 

of the engine and EGR stability was not affected. 

Efforts were extended to develop a regeneration 

protocol with the DPF. The regeneration target was 

to obtain 550°C at the DPF inlet, while operating the 

engine at Mode 6, 2300-rpm/4.2-bar bmep. The 

typical exhaust stack temperature for Mode 6 is 

395°C. During regeneration, the injection pulse was 

modified such that the pilot duration was extended to 

inject ~70% of the fuel with location of the peak 

pressure of combustion at 7° at top dead center 

(ATDC). The remaining fuel was injected late cycle, 

at ~45°ATDC. The DOC converts the late cycle 

injected hydrocarbons into heat for the DPF. The 

regeneration to a consistent 115 kilopascal (kPa)-

absolute backpressure from a fully loaded DPF takes 

90 minutes to complete. It appears the DOC is 

consuming >90% of the unburned hydrocarbons and 

oxygen, thus resulting in the slow regeneration of the 

DPF. However, the strategy was to regenerate the 

DPF at a condition that would not jeopardize the 

cylinder pressure transducers installed in the engine. 

Efforts are being made to alter the regeneration 

strategy to shorten the burn-off time. The base soot 

pack appears to be consistent, as determined by DPF 

weight, at the 115 kPa-absolute backpressure. Six 

regeneration cycles to 115 kPa-absolute backpressure 

revealed a spread of 3 grams between the maximum 

and minimum DPF weight recorded.

Low-NOx Operating Point Definition

The overall project goal is to define reasonable 

(not fully optimized) low-NOx operating conditions. 

Substantial reductions in nitrogen oxide index 

(NOxEI) are achieved by moving from the conditions 

of Phase I of this project to the stock OEM 

calibrations for the engine. Additional NOxEI 

reductions are obtained by varying the EGR rate and 

injection timing. The objective of this effort is to 

determine the operating points (e.g., injection timing 

and % EGR) to be used for each of the four modes in 

the PM Analysis Project-Phase II. For each mode, an 

attempt to determine the limit between stable and 

unstable engine operation for Low-NOx operating 

conditions was made. New fuel injectors and a fuel 

injection pump were installed in the OM 611 test 

engine. 

An initial methodology for determining the 

operating condition parameters was conducted with 

ECD-1 fuel at the Mode 11 (1500-rpm/2.62-bar 

bmep) operating condition. The approach was to 

start at the electronic control module point and add 

EGR and retard timing, then evaluate NOx reduction 

and fuel consumption increase. Initial data suggested 

EGR is more cost effective for NOx reduction in 

terms of fuel consumption, but leads to high smoke 

levels. Subsequently data sets have been generated 

for Mode 10 (2000-rpm/2.0-bar bmep), Mode 6 

(2300-rpm/4.2 bar-bmep), and Mode 22 (1500-rpm/

1.0 bar-bmep). Auto company participants were 

asked to obtain review/input from their driveability/

calibration staff on the EGR and timing sweeps.

The following summary was given for what type 

of vehicle operation each engine mode represents:

Mode 22: Catalyst Transition Temperature

Mode 11: Low speed cruise

Mode 10: Low speed cruise with slight 

acceleration

Mode 6: Moderate acceleration

The general rules for selecting Low-NOx

operating conditions were revised based on 

driveability and other considerations, and are shown 

in Table 1. The operating condition, which gave the 

largest NOx decrease while meeting the tabulated 

rules, was selected for the specific operating 

condition.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

60

Table 1. Rules for Defining Low-NOx Operating 

Conditions

The Low-NOx operating points and PM results 

for all fuels have been generated. Figure 1 shows the 

OEM and Low-NOx combustion timing and EGR 

windows for each test fuel. The box around the LowNOx points indicates the combustion timing and 

EGR tolerances outlined by the Ad Hoc CIDI 

working group. From Figure 1 it can be noted that all 

fuels fell within the tolerance box for the Low-NOx

operating condition. Manifold pressure constraints 

limited EGR levels, and fuel economy impacts 

limited combustion timing retard for NOx reduction.

Relative weighted emission index values were 

calculated for the test fuels, with the ECD-1 fuel used 

as the base. The relative NOx versus PM index tradeoff is shown in Figure 2. Included in Figure 2 are 

data for the OEM and Low-NOx operating 

conditions, with the results normalized to ECD-1 fuel 

at the OEM condition. Also included in Figure 2 are 

estimates of the 95% confidence intervals for the 

normalized data.

Based on the confidence intervals shown in 

Figure 2, the OEM operating condition NOx index of 

the ECD-1 and Diesel Emission Control-Sulfur 

Effects (DECSE) fuels are similar to all fuels except 

Neat Fischer-Tropsch fuel (FT100). FT100 is 

different from the BP15 and the BP15 based 

oxygenated fuels. The BP15 and BP15 based 

oxygenated fuels show a greater NOx index than 

ECD-1+TPGME at the OEM operating condition. 

The relative PM index results at the OEM operating 

condition suggest FT100 and the oxygenated fuels 

are similar. The ECD-1, BP15, and the DECSE fuels 

have higher PM indices than the other fuels, although 

the variability suggests this result is not significant. 

The BP15 fuel has higher PM response than the 

BP15-based oxygenated fuels for the OEM operating 

condition.

At the Low-NOx operating conditions, with the 

exception of the BP15 fuel, the fuels appear similar 

in regards to the relative NOx index. The PM index 

results at the Low-NOx condition spread apart, with 

the PM index from FT100 being lower than any other 

fuel, yet similar to the BP15+TPGME fuel. The PM 

index for ECD-1+TPGME is lower than the DECSE 

and BP15 fuels. Although the ECD-1+TPGME PM 

index is numerically lower than the ECD-1 fuel, the 

variability of the weighted result suggests they are 

MODE EGR BSFC BOOST SMOKE HC

6 >OEM 

(16%)

3% 

maximum 

increase

50% 

maximum 

decrease

100% 

maximum 

increase

No rule

10 >OEM 

(33%)

3% 

maximum 

increase

50% 

maximum 

decrease

100% 

maximum 

increase

No rule

11 >OEM 

(35%)

3% 

maximum 

increase

>0 100%

maximum 

increase

No rule

22 >OEM 

(51%)

3% 

maximum 

increase

N/A 100% 

maximum 

increase

100% 

maximum 

increase

Figure 2. Relative PM and NOx Emission Indices Trade 

Off for Test Fuels

Figure 1. Modal EGR and Combustion Timing 

Windows for All Fuels
Fuels for Advanced CIDI Engines FY 2002 Progress Report

61

similar. The PM index for the BP15+DBM 

oxygenated fuel is similar to the ECD-1, ECD1+TPGME, and BP15 fuels. The BP15+TPGME 

fuel is lower than the other oxygenated fuels for PM 

index at the Low-NOx operating condition, and only 

greater than FT100.

Conclusions

Overall, all fuels are statistically different for 

relative NOx index between the OEM and Low-NOx

operating conditions. In general, the relative PM 

indices are higher at the Low-NOx condition than the 

OEM condition.

Relative weighted fuel consumption was 

calculated and plotted with respect to relative NOx

index in Figure 3 for the OEM and Low-NOx

operating conditions. Overall, the fuel consumption 

penalty for the Low-NOx operating conditions is on 

the order of 2.5 to 3 percent.

Investigation of the role of fuels on tailpipe 

exhaust emissions of potentially toxicologically 

relevant compounds, utilizing a diesel oxidation 

catalyst and a catalyzed particulate filter, will be 

starting in late FY 2002.

FY 2002 Publication/Presentations

1. D.M. Yost and E.A. Frame, “Particulate Matter 

Analysis from an Advanced Diesel Engine; Phase 

I & II”, CIDI Engine Combustion, Emission 

Control, and Fuels R & D, Merit Review and Peer 

Evaluation, Argonne National Laboratory, 6-8 

June 2002.

2. Yost, et. al., “Impact of Engine Operating 

Conditions on Low-NOx Emissions in a LightDuty CIDI Engine using Advanced Fuels,” SAE 

2002-01-2884.

Figure 3. Relative Fuel Consumption Trade Off with 

NOx Indices for Test Fuels
Fuels for Advanced CIDI Engines FY 2002 Progress Report

62

C. Ultra-low Sulfur Reduction Emission Control Device/Development of an 

On-board Fuel Sulfur Trap

Ron Rohrbach and Rick Berkey (Primary Contacts), Tim Gavin

Honeywell Laboratories

101 Columbia Road

Morristown, NJ 07962-1021

(973) 455-2985, fax: (973) 455-2985, e-mail: Ron.Rohrbach@Honeywell.com

(419) 661-6704, fax: (419) 661-6789, e-mail: Rick.Berkey@Honeywell.com

DOE Technology Development Manager: Kenneth Howden

(202) 586-3631, fax: (202) 586-9811, e-mail: Kenneth.Howden@ee.doe.gov

Main Subcontractors: Honeywell Consumer Products Group Perrysburg, Ohio, Mack Trucks 

Hagerstown, Maryland, Marathon (MAP), Findlay, Ohio, Johnson Matthey, West Deptford, New 

Jersey, American Waste Industries, Maywood, Illinois

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

D. Sulfur Impacts

Tasks

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

Objective

• To develop and demonstrate proof-of-concept for an "on-vehicle" desulfurization fuel filter for heavyand light-duty diesel engines

Approach

• Phase I: Develop a conceptual design and resolve technical barriers concerning removal of sulfurcontaining species in low sulfur fuels

• Phase II: Implement high through-put screening techniques for chemistry selection and dynamic 

testing

• Phase III: Prototype design and testing: adapt research concept into a practical filter module and test 

its efficacy, produce prototype(s)

• Phase IV: Life cycle studies: study life cycle and regeneration options for spent filters

• Phase V: Validation Testing: engine testing with nitrogen oxides (NOx) adsorber and test prototype 

filter on a heavy-duty diesel engine for efficacy, and system performance, and component integration

Accomplishments

• Obtained representative low-sulfur diesel fuels obtained to meet the Environmental Projection Agengy 

(EPA) Tier II standards

• Completed analytical procedures for total sulfur and speciation completed
Fuels for Advanced CIDI Engines FY 2002 Progress Report

63

Future Directions

• Complete conceptual design and initiate analysis and testing

Introduction

The goal of this project is to develop an emission 

control device that can enable engine manufacturers 

to comply with the EPA emission standards including 

EPA Tier II Bin 5 for light-duty engines and the new 

'2007-Rule' for heavy-duty engines. The '2007' rule 

includes a new diesel fuel sulfur limit that has a 

maximum of 15 parts per million. Successful 

integration of the sulfur-removal component into a 

heavy-duty compressed ignition direct injection 

(CIDI) vehicle coupled with a post-combustion NOx

adsorber catalyst device will by default be applicable 

to light-duty CIDI engines. An onboard fuel sulfur 

removal device can expedite NOx adsorber 

technologies by assuring consistently low sulfur 

content and providing protection from misfueling 

and out-of-specification fuels. This should be 

accomplished at relatively modest cost to the enduser because the sulfur-removal device will be an 

add-on to the existing fuel system, and will be 

packaged in a conventional engineering format. It is 

anticipated the cost of the proposed sulfur-removal 

device to the consumer will represent no more than a 

low multiple of the current cost of a standard fuel 

filter. 

Approach

The main objective of this project is to 

demonstrate at the pilot scale level proof-of-concept 

for a fuel desulfurization filter that is able to reduce 

sulfur levels in the fuel to tolerable levels which 

enable the implementation of post-combustion NOx

adsorber technology. The technology developed will 

rely on Honeywell's expertise in reactive filtration 

technology. The targeted design and performance of 

this filter will be developed based on criteria supplied 

by Johnson Matthey (the NOx catalyst manufacturer) 

and Mack Trucks (the CIDI engine manufacturer). 

Development incorporates the following key 

elements: 1) survey of all applicable current and 

proposed approaches, 2) technical evaluation of 

potential technologies, 3) laboratory screening of 

down-selected approaches, 4) packaging of selected 

technologies for on-board configuration, 5) prototype 

design and preparation, 6) pilot scale life-testing and 

efficacy testing of the filter, and, 7) development of 

approaches to recycle/regenerate the spent filters. 

Results

This project began in April 2002. Representative 

fuel samples have been prepared and sufficient 

quantities of these are now in place to begin the 

experimental stage of the project. The analytical 

procedures are also now in place for measuring total 

sulfur and speciation of the sulfur contaminants.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

64

D. C1 Chemistry for Production of Clean Liquid Transportation Fuels and 

Hydrogen

Gerald P. Huffman (Primary Contact)

University of Kentucky, Consortium for Fossil Fuel Science

Suite 107, Whalen Building

533 South Limestone Street

Lexington, Kentucky 40506-0043

(859) 257-4027, fax: (859) 257-7215, e-mail: huffman@engr.uky.edu 

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov 

Main Subcontractors: West Virginia University, Morgantown, West Virginia, University of 

Pittsburgh, Pittsburgh, Pennsylvania, University of Utah, Salt Lake City, Utah, Auburn University, 

Auburn, Alabama

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

G. Advanced Fuel Production and Cost

Tasks

5. Refinery and Fuel Processing Economics

Objectives

• C1 chemistry refers to reaction processes that use feedstocks that consist of molecules containing one 

carbon atom [synthesis gas (a mixture of CO and H2), methane (CH4), carbon dioxide (CO2), carbon 

monoxide (CO), and methanol (CH3OH)]. The major objectives of this project are to develop C1 

technology for the production of ultra-clean, high efficiency, liquid transportation fuels and hydrogen.

Approach

• The Consortium for Fossil Fuel Science (CFFS) is a research consortium with participants from five 

universities - the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia 

University, and Auburn University. The CFFS universities are collaborating on a research project to 

develop C1 chemistry processes to produce clean transportation fuel from resources such as coal and 

natural gas, which are more plentiful domestically than petroleum. The processes under development 

will convert feedstocks containing one carbon atom per molecular unit into ultra clean liquid 

transportation fuels (gasoline, diesel, and jet fuel) and hydrogen. The feedstocks include syngas, a 

mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, 

methane, methanol, carbon dioxide, and carbon monoxide. An Industrial Advisory Board with 

representatives from Chevron, Eastman Chemical, Energy International, the Department of Defense, 

Conoco, and Tier Associates provides guidance on the practicality of the research.

Accomplishments

• Small additions of compounds with carbon-carbon triple bonds to the Fischer-Tropsch synthesis have 

been shown to improve the products by increasing their oxygenate content.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

65

• Operation of Fischer-Tropsch synthesis under supercritical fluid (SCF) solvent conditions increases 

CO conversion, decreases the yield of C1-C3 gases, and increases C7-C24 1-olefin yield.

• New platinum/tungsten/zirconium dioxide (Pt/W/ZrO2) catalysts have been developed that are very 

effective at cracking Fischer-Tropsch wax into diesel fuel.

• Nanoscale, binary, iron-based catalysts containing molybdenum (Mo), palladium (Pd), or nickel (Ni) 

are very active for the decomposition of methane and ethane, producing pure hydrogen and carbon 

nanotubes. The nanotubes derived from ethane exhibit an interesting stacked traffic cone structure.

• A small diesel engine test facility has been established and used to demonstrate the beneficial effects 

of oxygenate additives in reducing particulate matter (PM) emissions. 

Future directions

• The CFFS will continue to work on further improvement in the Fischer-Tropsch synthesis and on 

developments of innovative approaches for producing pure hydrogen.

Introduction

The CFFS C1 chemistry research program has 

produced a number of significant research 

achievements in its first three years. In this report, a 

brief summary is given of some of these 

achievements, with emphasis on Fischer-Tropsch 

synthesis of fuels and hydrogen.

Approach and Results

Novel Approaches to Fischer-Tropsch Synthesis 

Fischer-Tropsch synthesis is the best-known C1 

chemistry process for producing transportation fuel 

from syngas. CFFS research has produced a number 

of innovations on the Fischer-Tropsch process. In 

research conducted at the University of Pittsburgh, it 

has been discovered that small (~1%) additions of 

probe molecules with carbon-carbon triple bonds 

dramatically enhance the presence of oxygenated 

products. This significantly decreases emissions of 

PM, which is a critical issue for diesel and jet fuels. 

Using 1-hexyne as the probe molecule additive, 

much higher yields of Fischer-Tropsch products in 

the C6 to C20 range were obtained. Gas 

chromatography-mass spectroscopy analysis 

detected such oxygenated species as 1-heptanal, 2-

heptanal, 1 heptanol, 1-octanol, 1-undecanol, and 1-

tetradecanol.

Other work at the University of Pittsburgh has 

focused on catalytic hydrocracking of FischerTropsch wax, which is typically 65-75% of the 

Fischer-Tropsch product. Pt/W/ZrO2 catalysts have 

been developed that are very effective at converting 

Fischer-Tropsch wax into a product that is 

approximately 70% diesel fuel, 25% gasoline, and 

5% lube oil.(1,2)

Fischer-Tropsch synthesis in supercritical fluid 

(SCF) solvents is under investigation at Auburn 

University. The SCF media has the advantage of 

gas-like diffusivities and liquid-like solubilities and 

heat transfer properties. In experiments using SCF 

hexane and a commercial cobalt Fischer-Tropsch 

catalyst, total syngas conversion was increased over 

the gas-phase reaction from approximately 50% to 

80%, and selectivity to heavier products and olefins 

was increased.(3,4) The yield of C1-C3 gases was 

decreased by approximately 40% in the SCF 

reaction, while the C7-C24 1-olefin yield was 

Figure 1. The yield of 1-olefins from FT sythesis is 

markedly increased under SCF conditions.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

66

markedly increased (Figure 1). Future research will 

focus on other SCF solvents (propane, pentane, 

carbon dioxide, and mixtures), novel catalyst 

designs, and pressure tuning to alter product 

selectivity and yield.

Hydrogen

Traditionally, hydrogen has been produced by 

partial oxidation of methane or gasification of coal to 

produce synthesis gas, followed by the water-gas 

shift reaction to convert CO to CO2 and produce 

more hydrogen. To achieve the purity required by 

polymer-electrolyte proton exchange membrane fuel 

cells (<10 ppm CO), further purification (reverse 

methanation or catalytic oxidation of CO) and 

separation procedures are required. Research at the 

University of Kentucky is focused on producing pure 

hydrogen in a single step by catalytic 

dehydrogenation of hydrocarbons. Nanoscale, 

binary Fe-based catalysts containing Mo, Pd or Ni 

and supported on high surface area alumina have 

been developed that are very effective for the nonoxidative catalytic decomposition of methane into 

pure hydrogen and carbon nanotubes.(1) The key 

factor influencing catalyst activity is the efficient 

removal of carbon from the catalyst surface in the 

form of multi-walled nanotubes, a valuable byproduct with potential applications in electronics, 

high strength materials, and hydrogen storage. More 

recent experiments on the catalytic dehydrogenation 

of ethane have also produced promising results.(2) 

Yields of 80-90% of pure hydrogen have been 

obtained from both methane and ethane at relatively 

low temperatures of 700-800o

C. The nanotube 

structure produced by ethane exhibits an interesting 

stacked traffic cone structure at low decomposition 

temperatures (500o

C, Figure 2). Such open nanotube 

structures appear promising for hydrogen storage. 

This is being investigated in collaboration with Dr. 

Brad Bockrath, a scientist at the U.S. Department of 

Energy National Energy Technology Laboratory. 

Future research will be focused on catalytic 

dehydrogenation of liquid hydrocarbons, a critical 

problem for fuel cell-powered vehicles, and on 

development of a continuous process for catalytic 

production of pure hydrogen and carbon nanotubes 

from light alkanes. 

Conclusions

Small additions (1%) of compounds with carboncarbon triple bonds to the Fischer-Tropsch synthesis 

improve the product fuels by increasing their 

oxygenate content.

Operation of Fischer-Tropsch synthesis under 

SCF solvent conditions increases both the yield and 

olefin content of the products.

Pure hydrogen and carbon nanotubes, a valuable 

byproduct, are readily produced by catalytic 

decomposition of methane or ethane using nanoscale, 

binary, iron-based catalysts containing molybdenum, 

palladium, or nickel and supported on alumina.

New Pt/W/ZrO2 catalysts have been developed 

that are very effective at cracking Fischer-Tropsch 

wax into diesel fuel.

Other Results of Interest

Interesting results from several additional C1 

research projects are briefly summarized below.

• C1 processes for producing ethylene and 

propylene from methanol are being 

Figure 2. Carbon nanotubes formed by decomposition 

of ethane at 500o

C exhibit an interesting 

nested traffic cone structure.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

67

developed at Auburn University. These 

processes use novel silica-aluminophosphate 

catalysts. 

• Catalytic C1 processes have been developed 

at West Virginia University, Auburn 

University, and the University of Utah to 

produce organic carbonates, higher ethers, 

and higher alcohols for use as additives to 

diesel fuel or gasoline. Tests conducted 

using a small diesel engine test facility 

recently established at the University of Utah 

have established that such additives 

significantly decrease particulate matter 

emissions.

• Binary transition metal carbide catalysts 

developed at West Virginia University are 

found to have excellent activities and 

lifetimes for reforming of methane using 

carbon dioxide.

References

1. S. Zhang, Y. Zhang, J.W. Tierney and I. Wender, 

Fuel Process. Technol., 69, (2001) 59-71.

2. S. Zhang, Y. Zhang, J.W. Tierney and I. Wender, 

Applied Catalysis A: General, 193 (2000) 155-

171.

3. X. Huang, C.W. Curtis, C.B. Roberts, ACS, Fuel 

Chem. Div. Preprints, 47(1), 150-153, (2002).

4. X. Huang, C.B. Roberts, "Supercritical Fluid 

Hexane Based Fischer-Tropsch Synthesis on a 

Cobalt Catalyst" submitted to Ind. Eng. Chem. 

Res. (2002).

5. N. Shah, D. Panjala, and G.P. Huffman, Energy & 

Fuels, 15 (2001) 1528-1534.

6. A. Makuni, D. Panjala, N. Shah, and G.P. 

Huffman, ACS, Fuel Chem. Div. Preprints, 47(2) 

(2002), to be published.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

68

VI. MODELING/DATA ANALYSIS/ASSESSMENTS

A. The Impact of Oxygenated Blending Compounds on PM and NOx Formation 

of Diesel Fuel Blends

Charles K. Westbrook (Primary Contact), William J. Pitz

Lawrence Livermore National Laboratory

P. O. Box 808, L-091

Livermore, CA 94551

(925) 422-4108, fax: (925) 422-2644, e-mail: westbrook1@llnl.gov

DOE Technology Development Manager: John Garbak 

(202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

B. PM Emissions

Tasks

5e. R&D on PM Reducing Technologies

Objectives

• Characterize the role of oxygenated additives in reduction of particulate matter (PM) emissions from 

diesel engines

• Develop detailed chemical kinetics reaction models for oxygenated hydrocarbon fuel additives

• Compare soot reduction potential of different oxygenated additives

Approach

• Identify potential diesel additives and their molecular structures

• Develop kinetic reaction mechanisms for the oxygenated additives

• Compute the ignition of each fuel mixture or model the flame structures for the fuel and additive 

mixtures

• Compare predicted levels of PM and NOx with and without additives and use a detailed chemical 

models to determine the mechanisms for the changes

Accomplishments

• Predicted reductions in PM emissions for mixtures of diesel fuel with addition of biodiesel fuels, 

dibutyl maleate and tripropylene glycol monomethyl ether

• Established that newly proposed oxygenated additives suppressed PM production at approximately the 

same rate as previous additives studied

• Based on kinetic model predictions, determined limits of validity of existing correlation between 

amount of oxygen in diesel/additive fuel mixture and PM reduction that agreed with experimental 

results in diesel engines
Fuels for Advanced CIDI Engines FY 2002 Progress Report

69

Future Directions

• Extend model capabilities to additional oxygenated blending compounds

• Increase collaborations with projects outside Lawrence Livermore National Laboratory (LLNL) 

dealing with diesel fuel issues

Introduction

Experimental diesel engine studies have 

indicated that when oxygen is added to diesel fuel, 

soot production in the engine is reduced. The soot 

reduction appears to be largely independent of the 

way oxygen is incorporated into the reactants, 

including entrainment of additional air into the 

reacting gases or direct inclusion of oxygen atoms 

into the diesel fuel molecules. 

The present study examines possible diesel fuels 

which have incorporated oxygen atoms into the 

molecular structure of the fuel itself. Following past 

studies of oxygenated diesel fuels such as methanol, 

dimethyl ether, and dimethoxy methane, this work 

studies oxygenated fuels which have been selected 

by industry consultants on the basis of potential for 

improving performance in diesel engines.

Approach

Chemical kinetic modeling has been developed 

uniquely at LLNL to investigate combustion of 

hydrocarbon fuels in practical combustion systems 

such as diesel engines. The basic approach is to 

integrate chemical rate equations for chemical 

systems of interest, within boundary conditions 

related to the specific system of importance. This 

approach has been used extensively [1-4] for diesel 

engine combustion, providing understanding of 

ignition, soot production, and NOx emissions from 

diesel engines in fundamental chemical terms.

The underlying concept is that diesel ignition 

takes place at very fuel-rich conditions, producing a 

mixture of chemical species concentrations that are 

high in those species such as acetylene, ethene, 

propene and others which are well known to lead to 

soot production. Some changes in combustion 

conditions reduce the post-ignition levels of these 

soot precursors and reduce soot production, while 

other changes lead to increased soot emissions. The 

LLNL project computes this rich ignition using 

kinetic modeling, leading to predictions of the effect 

such changes might have on soot production and 

emissions.

Kinetic reaction models were developed for the 

oxygenated additives proposed by a DOE/industry 

panel of experts. We then computed diesel ignition 

and combustion using heptane [5] as a reasonable 

diesel fuel surrogate model, mixed with oxygenated 

additives. The impact of the additive on predicted 

levels of soot-producing chemical species was then 

assessed.

Results

Using operational insights derived from recent 

diesel engine experiments by Dec [6], we assumed 

that soot production in diesel combustion occurs 

from reactions of chemical species created in fuelrich ignition near the fuel injection location. Because 

there is insufficient oxygen in this region to burn the 

fuel completely, the hydrocarbon species remaining 

there react instead to produce soot. Our kinetics 

calculations show that when the fuel itself contains 

some oxygen, that oxygen helps convert more of the 

ignition products into chemical species that do not 

contribute to soot production. 

During the past year, the LLNL project has 

examined two important oxygenated hydrocarbon 

species that have been proposed as possible diesel 

fuels. These are dibutyl maleate (DBM) and 

tripropylene glycol monomethyl ether (TPGME), 

both of which include significant amounts of oxygen 

imbedded in the primarily hydrocarbon fuel 

molecule. Schematic diagrams of the structures of 

these two species are shown Figure 1. Detailed 

chemical kinetic reaction mechanisms were 

developed for both of these fuels, and the resulting 

models were used to assess their sooting tendencies. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

70

The model calculations indicate that the 

distribution of oxygen atoms within the fuel 

molecule can have a significant influence on the antisooting effects of the oxygen atoms. Our work 

supports a view that oxygen atoms within a fuel 

molecule form C-O bonds that remove the C atom 

from the pool of species which can eventually 

produce soot. Each O atom removes one C atom 

from the sooting environment, and TPGME is an 

excellent example of a fuel in which this mechanism 

can be seen.

However, in DBM, the available oxygen atoms 

are less well distributed, and in some cases two 

oxygen atoms produce CO2 directly from the 

decomposition of the additive. As a result, the total 

population of O atoms in the fuel are not as effective 

at sequestering carbon atoms as in TPGME, so DBM 

is less effective as a soot reduction fuel additive than 

TPGME. This analysis is consistent with recent 

experimental results from Sandia National 

Laboratories in Livermore. Ongoing kinetic analyses 

are examining the implications of these results and 

may lead to new definitions of potentially important 

diesel fuels for engine combustion. In addition, this 

work may lead to better analyses of the soot 

reduction capacities of other alternative diesel fuels. 

In particular, these kinetic results suggest that 

biodiesel fuels may have the same reduction in 

oxygen additive effectiveness as that noted above for 

DBM. The methyl ester group in biodiesel fuels has 

the potential to produce CO2 directly, making the 

oxygen content of the biodiesel fuel less able to 

capture one C atom for every O atom in the fuel and 

reducing the proportional effectiveness of the fuelbound oxygen.

Conclusions

Kinetic modeling provides a unique tool to 

analyze combustion properties of potential 

alternative fuels for diesel engines. This can provide 

a way to screen proposed new fuel classes or types 

that may be important in applied studies. A kinetic 

model can be very cost-effective as an alternative to 

experimental analyses, and computations can also 

provide a fundamental explanation of the reasons for 

the observed results. 

References

1. Fisher, E. M., Pitz, W. J., Curran, H. J., and 

Westbrook, C. K., "Detailed Chemical Kinetic 

Mechanisms for Combustion of Oxygenated 

Fuels", Proc. Combust. Inst. 28: 1579-1586 

(2000). 

2. Curran, H. J., Fisher, E. M., Glaude, P.-A., 

Marinov, N. M., Pitz, W. J., Westbrook, C. K., 

Layton, D. W., Flynn, P. F., Durrett, R. P., zur 

Loye, A. O., Akinyemi, O. C., and Dryer, F. L., 

"Detailed Chemical Kinetic Modeling of Diesel 

Combustion with Oxygenated Fuels," Society of 

Automotive Engineers paper SAE-2001-01-0653 

(2001).

3. Flynn, P.F., Durrett, R.P., Hunter, G.L., zur Loye, 

A.O., Akinyemi, O.C., Dec, J.E., and Westbrook, 

C.K., "Diesel Combustion: An Integrated View 

Combining Laser Diagnostics, Chemical Kinetics, 

and Empirical Validation", Society of Automotive 

Engineers paper SAE-1999-01-0509 (1999).

4. Curran, H. J., Fisher, E. M., Glaude, P.-A., 

Marinov, N. M., Pitz, W. J., Westbrook, C. K., 

Layton, D. W., Flynn, P. F., Durrett, R. P., zur 

Loye, A. O., Akinyemi, O. C., and Dryer, F. L., 

"Detailed Chemical Kinetic Modeling of Diesel 

Combustion with Oxygenated Fuels," Society of 

Automotive Engineers paper SAE-2001-01-0653 

(2001).

Figure 1. Schematic Chemical Structure Diagrams 

for Proposed oxygenated Diesel Fuel 

Components Tripropylene Glycol 

Monomethyl Ether and Dibutyl Maleate
Fuels for Advanced CIDI Engines FY 2002 Progress Report

71

5. Curran, H. J., Gaffuri, P., Pitz, W. J., and 

Westbrook, C. K., "A Comprehensive Modeling 

Study of n-Heptane Oxidation," Combustion and 

Flame 114, 149-177 (1998).

6. Dec, J.E., "A Conceptual Model of DI Diesel 

Combustion Based on Laser-Sheet Imaging," SAE 

publication SAE-970873 (1997).
Fuels for Advanced CIDI Engines FY 2002 Progress Report

72

B. System Emissions Reduction Analysis for Automobiles, Light Trucks, and 

Heavy-Duty Engines

Matthew Thornton (Primary Contact)

National Renewable Energy Laboratory

1617 Cole Boulevard

Golden, CO 80401

(303) 275-4273, fax: (303) 275-4415, e-mail: matthew_thornton@nrel.gov

DOE Technology Development Managers: 

Stephen Goguen: (202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

Bob Kost: (202) 586-2334, fax: (202) 586-6109, e-mail: Robert.Kost@ee.doe.gov 

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Main Subcontractor: Ricardo, Inc., Belleville, Michigan

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

A. Fuel Property Effects on Engine Emissions and Efficiency

B. Fuel Property Effects on Exhaust Emission Control System Technology

D. Sulfur Impacts

E. Toxic Emissions

F. Advanced Fuel Production and Cost

Tasks

2. Fuel & Lubricant Properties - Engine-Out Emissions

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

4. Develop Empirical Relationships

Objectives

• Establish system emissions reduction (SER) analysis modeling components.

• Develop and use systems level analysis tools that incorporate the empirical emission relationships and 

first principle models to identify the best pathways for achieving the technical targets for compression 

ignition direct injection (CIDI) engines, identified in the Advanced Petroleum-Based Fuels (APBF) 

Multiyear Program Plan.

Approach

• Conduct an analysis comparing the emissions reduction and fuel penalty trade-off of three CIDI 

emissions control technology bundles for the sport utility vehicle (SUV) analysis platform. 

• Develop an array of 1-D engine models to match the APBF activity analysis platforms.

• Augment the Advanced Vehicle Simulator (ADVISOR) with new component data and engine maps 

developed from the 1-D engine models.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

73

• Recommend future analyses and continue to expand input databases, identify gaps in the data required 

for accurate predictions, and use this information as a guide to develop future research and 

development projects. 

Accomplishments

• Initiated an analysis comparing the emissions reduction and fuel penalty trade-off for selective 

catalytic reduction (SCR), nitrogen oxides (NOx) adsorber, and DeNOx catalysts all with diesel 

particulate filters for the SUV platform equipped with a 5.0 liter CIDI engine.

• Developed two of the four planned 1-D engine models using the WAVE software. The 2.2 liter, 5.0 

liter, and 7.3 liter models are complete, and the 11.0 liter model is currently under development.

• Used the 7.3 liter WAVE 1-D engine model to demonstrate the process for developing engine 

emissions and efficiency maps that can be used in ADVISOR.

Future Directions

• Expand component models and refine model integration.

• Analyze pathways for reducing emissions for three platforms and investigate specific applications of 

analysis tools such as the effect of compression ratio, exhaust gas recirculation (EGR), and 

aftertreatment devices on efficiency, and fuel formulation effects on emissions.

• Develop a process to validate the model at a systems level.

• Identify and collect relevant data already existing from research partners.

Introduction

The APBF program seeks to identify and 

establish the ability of advanced petroleum fuels and 

non-petroleum fuel blending components to enable 

light-duty CIDI vehicles and heavy-duty CIDI 

engines to meet future emission standards, while 

continuing to improve engine efficiency and 

durability. 

A component of the APBF program is 

establishing a SER analysis framework for 

automotive, light truck, and heavy-duty engine 

applications. This framework focuses on applying a 

systems approach to analyzing emission reduction 

pathways and fuel options. Establishing the SER 

analysis approach requires analyzing available data 

and developing maps and submodels to add to the 

existing ADVISOR vehicle system model. 

Approach

The National Renewable Energy Laboratory 

(NREL) is using fuel property and emission data 

from Advanced Petroleum Based Fuels - Diesel 

Emissions Control (APBF-DEC) and associated 

empirical data relationships, in conjunction with 

first-principle models to evaluate the most promising 

pathways for reducing emissions using the SER 

approach. The system concept consists of an 

analysis tool that accounts for the interaction of fuel, 

combustion strategy, and aftertreatment. This 

approach is being built around NREL's ADVISOR 

(advanced vehicle simulator). ADVISOR requires a 

detailed map of gaseous emissions, particulate matter 

(PM) emissions (real-time), fuel consumption, 

exhaust and EGR temperatures, at many engine 

speeds and loads. Such maps can be acquired as 

actual datasets from engine testing or generated using 

one-dimensional engine models with a more limited 

(i.e. 10-mode) dataset and various engine parameters 

as input. This work will involve continually 

developing these engine performance maps using 

data acquired from other APBF projects, as well as 

incorporating conversion efficiency data (as a 

function of exhaust temperature and flow 

parameters) for various emission control devices. 

Empirical relationships of emissions and specific, 

targeted fuel properties such as sulfur content, cetane 

number, and aromatic content will be used to 

estimate the impacts of fuel properties. These 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

74

components will be used to evaluate the best 

pathways for achieving the technical targets of the 

overall APBF-DEC program. 

The SER approach is designed around the 

following: 

• Use ADVISOR as an analysis platform to 

link system components (i.e. empirical 

emission relationships, first principle 

models, and parameterized models). Identify 

the best pathways for achieving the technical 

targets on a vehicle level as defined by the 

APBF program.

• Collect data sets from engine laboratories 

and develop empirical relationships linking 

emissions to fuel properties.

• Develop 1-D engine models for vehicle 

platforms for which complete datasets are 

not available. Expand the CIDI engine map 

library in ADVISOR and provide enhanced 

exhaust gas characteristics to be used as 

inputs to aftertreatment submodels.

• Expand the emissions control and 

aftertreatment modeling capabilities in 

ADVISOR in order to enhance emissions 

predictions.

Results

Three primary activities contributed to results in 

FY02. The first was emissions reduction fuel penalty 

trade-off analysis of three CIDI emissions control 

technologies for one vehicle analysis pathway. The 

second was the development of 1-D engine models 

for each of the analysis platforms using the WAVE 

software. The third was the development of engine 

efficiency and emissions maps for ADVISOR using 

the 1-D engine models. 

Emissions Reduction Fuel Penalty Trade-off 

Analysis

The first phase of this effort was to assess the 

emissions reduction and fuel economy trade-offs of 

three emissions control technology bundles that are 

anticipated to be the best approached to meeting Tier 

2 emissions standards for CIDI applications in the 

near term. 

The technologies evaluated included:

• NOx adsorber catalyst with a catalyzed 

particulate filter

• SCR with a catalyzed particulate filter

• Lean NOx catalyst with a catalyzed 

particulate filter

Each of these emissions control systems will be 

evaluated for the SUV or light-duty pick-up CIDI 

(5.0 L) vehicle platforms.

For the purpose of this analysis, it was assumed 

that the analysis vehicle will be equipped with stateof-the-art engine technology, including charge air 

cooler, turbocharger, and EGR. In addition, it will be 

assumed that all systems were used in conjunction 

with ultra low sulfur fuel (< 15 parts per million). 

The emissions reduction estimates and fuel 

consumption trade-off analysis were developed in 

two separate formats. The first format reports the 

fuel consumption relative to achieving the Tier 2 -bin 

5 emission levels (0.07 grams per mile [g/mi] NOx

and 0.01 g/mi PM). The fuel consumption change 

was reported in percent change from a baseline of a 

current production diesel vehicle for each platform. 

That is, simulated emissions and fuel consumption 

baselining was required as part of this effort. The 

second format reports the fuel consumption and 

emissions reduction trade off incrementally, as grams 

of fuel used per gram of emission avoided. Finally, 

the above information is reported graphically, 

showing the maximum simulated reduction 

capabilities of all three, technology bundles and the 

accompanying fuel consumption increases. 

To the highest degree possible, all aspects of the 

emissions control systems will be accounted for in 

this analysis. That is, all reductants (fuel or urea) and 

all electrical or other engine parasitic load 

requirements are converted into equivalent fuel 

consumption units. This effort will require the use of 

a variety of analysis tools including ADVISOR, 

WAVE and MATLABTM. In some cases it will be 

necessary to utilize a variety of modeling and 

analytical tools, as well as empirical information and 

data from published studies in order to fill in gaps in 

simulation capabilities. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

75

To date, baseline engine-out simulations have 

been competed, an SUV vehicle model has been 

developed in ADVISOR, and an SCR model has 

been developed. Details related to the general 

emissions control modeling approach and the SCR 

model follow.

The general framework for all the emissions 

control technology models is built around 

MATLABTM SimulinkTM. These 1-D, quasi-steady 

models are designed for an "intermediate level of 

complexity" and include:

• Mass transfer through the catalyst

• Diffusion of exhaust species to and from the 

monolith

• Heat transfer between the monolith and the 

exhaust stream and between the monolith 

and the ambient

• Global chemical reaction kinetics

• Heat of reaction

The models allow the user to define the number 

of axial segments into which the catalyst is divided. 

All simulations for this study will be performed with 

20 to 25 segments.

The first of the aftertreatment technologies 

modeled was the urea-based SCR. For this study, a 

somewhat simplified model is used. A urea solution 

is injected into the exhaust upstream from the 

catalyst, which ideally, given sufficient time and 

exhaust temperature, decomposes to ammonia. The 

ammonia then reduces the NOx to N2 in the presence 

of the precious metals of the catalyst. Although 

sources report many NOx reduction mechanisms, a 

five reaction set approach was taken to model the 

SCR: 

 4NO + 4NH3 + O2 4N2 + 6H2O

 NH3 + MOx-1 MOx (ammonia storage)

 MOx NH3 + MOx-1 (ammonia release)

 2NO2 + 4NH3 + O2 3N2 + 6H2O

 NO + NO2 + 2NH3 2N2 + 3H2O

More complex reaction sets are difficult to tune, 

especially given the level of detail of data in 

published literature. Likewise, global chemical 

reaction rate equations are difficult to locate. 

Therefore, the following rate mechanisms were 

assumed:

Where:

R = reaction rate (kmol/s)

[x] = mole fraction of species 'x'

T = monolith temperature (K)

To tune the pre-exponential and exponential 

constants in the rate equations, data from Blakeman, 

Chandler, John, and Wilkins was used. Catalyst 'B' 

of this reference exhibits very good performance at 

low temperatures, especially when sufficient NO2 is 

present. Blakeman et al. reports catalyst 'B' results 

with NO only stream and a 50/50 mix of NO and 

NO2, which allowed tuning of both reactions 1 and 5. 

Reaction 4 was assumed to have the same constants 

as Reaction 1. The model achieves a very good 

match with the data between 150 and 275oC. Since 

there is no NO2 in the stream, just NO, this result is 

solely due to Reaction 1. 

Development of 1-D Engine Models

The development of four 1-D engine models 

using the WAVE software was planned under this 

task. The primary objective of this was to develop 

detailed, calibrated WAVE engine models (with 

supporting data) of the following three diesel engine 

types, intended to match the SER analysis platforms.

• Automobile class 2.2 liter turbocharged high 

speed direct injection (HSDI) 

[ ][ ]

[ ] 3

/

1

3

/

1

1 1

1

1 C e NH

A e NO NH

R

D T

B T

−

−

+ =

[ ][ ] 3 3 MO NH 3 R A x =

[ ][ ]

[ ]3

/

4

2 3

/

4

4 4

4

1 C e NH

A e NO NH

R

D T

B T

−

−

+ =

[ ][ ][ ]

[ ]3

/

5

2 3

/

5

5 5

5

1 C e NH

A e NO NO NH

R

D T

B T

−

−

+ =

[ ][ ] 2 2 MO 1 NH 3 R A x− =
Fuels for Advanced CIDI Engines FY 2002 Progress Report

76

• Light-duty truck class turbocharged 7.3 liter

• Light-duty truck class turbocharged scaled 

5.0 liter

• Heavy-duty truck class turbocharged 11.0 

liter

To date, three of the four models have been 

developed. These include the 2.2 liter HSDI engine, 

the Navistar 7.3 liter turbocharged CIDI V8, and the 

5.0 liter engine scaled from the 7.3 liter model. 

Figure 1 shows the WAVE graphical representation 

of the 2.2 liter HSDI engine.

Development of ADVISOR Engine Maps from 1-D 

Engine Models

One of the intended functions of the above 

models is to use them as a pre-processor for 

ADVISOR. In this capacity the WAVE model would 

be used to sweep an array of engine operating points 

in order to produce efficiency and performance maps 

that could then be integrated with ADVISOR. The 

7.3 liter model was used to produce an engine 

efficiency map in the MATLABTM SimulinkTM

environment so that it could be used by ADVISOR. 

This process consists of performing a WAVE 

simulation over ten speed and load points and 

processing then output into an appropriate matrix 

format for ADVISOR. Figure 2 shows the engine 

efficiency map developed from a WAVE simulation 

for the 7.3 liter Navistar engine. This map can be 

compared with the efficiency map for this engine 

based on data from an engine dynamometer over 

eight steady-state points, shown in Figure 3. The 

map developed from simulated data match the 

empirical map reasonably well, with an error range 

of 2-12 percent depending on the operating point.

Conclusions

Progress has been made on developing 

components necessary to enable a system level 

analysis of the emissions pathways for advanced 

engines and vehicles. Relationships between fuel 

and emissions data obtained from testing engines, 

vehicles, and advanced emission control devices are 

being developed in submodels that form the building 

blocks of the SER framework. This framework will 

provide the capability to predict potential emissions 

and efficiency improvements for automobiles, lighttrucks, and heavy-duty engines. 

Figure 1. Graphical Representation of the WAVE 

2.2 L HSDI Engine Model

Figure 2. Engine Efficiency Map Developed with 

WAVE for the 7.3 L Engine

Figure3. Engine Efficiency Map Developed from 

Dynamometer Data for the 7.3 L Engine
Fuels for Advanced CIDI Engines FY 2002 Progress Report

77

Future efforts will focus on: 1) expanding the 

number of parameterized aftertreatment submodels, 

2) enhancing the empirical data relationships 

previously developed, and 3) applying the analysis 

tool. Significant effort will be focused on continuing 

to develop an integrated systems model.

Additional effort will be devoted to developing 

fuel property versus emissions correlations using 

NREL's existing database, enhancing NREL's 

database, and incorporating other fuel property 

emissions databases such as the one being developed 

by the Environmental Protection Agency. The 

project will continue to focus on evaluating three 

technology platforms (automobile, light-duty truck, 

and heavy-duty engine), and will emphasize the 

inclusion of a heavy-duty engine model into 

ADVISOR. The project will also evaluate 

applications related to these platforms as required by 

DOE and the needs of the APBF-DEC program. The 

SER project will provide DOE with analysis of the 

potential effectiveness of different combinations of 

fuel, CIDI engine control strategies, and emission 

control devices on achieving emission reduction 

targets and engine and vehicle performance goals.

References

1. Se H. Oh, and James C. Cavendish, "Transients of 

Monolithic Catalytic Converters: Response to 

Step Changes in Feedstream Temperature as 

Related to Controlling Automobile Emissions," 

Ind. Eng. Chem. Prod. Res. Dev, Vol. 21, 1982, pp 

29-37. 

2. A. Lubeski, "Real-Time Catalytic Converter 

Temperature Estimator In the Powertrain 

Controller," SAE Paper 2000-01-0651.

3. P. G. Blakeman, G. R. Chandler, G. A. John, and 

A. J. J. Wilkins, "Investigations into NOx

Aftertreatment with Urea SCR for Light-Duty 

Diesel Vehicles," SAE Paper 2001-01-3624. 

4. David K. S. Chen, Edward J. Bissett, Se H. Oh, 

and David L. Van Ostrom, "A Three Dimensional 

Model for the Analysis of Transient Thermal and 

Conversion Characteristics of Monolithic 

Catalytic Converters," SAE Paper 880282.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

78

C. Fuel Property Database

Teresa Alleman (Primary Contact), Robert McCormick, Paul Bergeron, Mark Winter, Karen 

Guilbeault

National Renewable Energy Laboratory

1617 Cole Boulevard

Golden, CO 80401

(303) 275-4514, fax: (303) 275-4415, e-mail: teresa_alleman@nrel.gov 

DOE Technology Development Managers: 

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Steve Goguen: (202) 586-8044, fax: (202) 586-2476, e-mail: Stephen.Goguen@ee.doe.gov

This project also addresses the following DOE R&D Plan barriers and tasks:

Barriers

A. Fuel Property Effects on Engine Emissions and Efficiency

B. Fuel Property Effects on Exhaust Emission Control System Technology

D. Sulfur Impacts

E. Toxic Emissions

F. Ultra-fine Particles

Tasks

2. Fuel & Lubricant Properties - Engine-Out Emissions

3. Fuel & Lubricant Properties - Exhaust Emission Control and Emissions

4. Develop Empirical Relationships

Objectives

• Establish and populate a web-based, searchable fuel property database for the Advanced PetroleumBased Fuels (APBF) project which links to available emissions data.

• Utilize the database to develop empirical relationships between emissions and fuel properties.

Approach

• Define the fuel properties, engine and vehicle characteristics, and emissions to be included in the 

database. 

• Build the database, web pages and appropriate web interfaces for the searchable database. 

Accomplishments

• Searchable fuel property database completed and available on World Wide Web at http://

www.ott.doe.gov/fuelprops/.

• Fuel property database linked to existing heavy vehicle emissions database.

• Several new fuels and over 150 emissions records added in the last year.

• Data in the database can be used to examine the trends in exhaust emissions over time.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

79

Future Directions

• Continue to populate fuels and emissions databases as data become available.

• Complete expansion of the emissions database to include light-duty emissions data and engine 

emissions data, particularly from the APBF project.

Introduction

The effect of fuel properties, such as cetane 

number, aromatic content, and sulfur content, on 

exhaust emissions from diesel engines has been 

extensively studied. The use of alternative and 

advanced fuels (i.e. biodiesel, ultra-low sulfur diesel 

[ULSD], and Fischer-Tropsch diesel) in diesel 

engines and the resultant emissions effects have also 

been well documented. The impact of various fuel 

properties on diesel engines affects such systems as 

fuel injectors and exhaust aftertreatment devices. 

Thus, a detailed understanding of the influence of 

fuel properties is imperative to meeting future 

emissions targets without sacrificing operability and 

durability.

The APBF project studies a variety of fuels and 

fuel components and their impacts on exhaust 

emissions. The Liquid Fuel Property Database 

provides a single location for archiving data on fuels 

used in support of APBF research projects. The 

database is utilized to compare fuels, determine the 

effect of fuel properties on exhaust emissions, and 

investigate changes in exhaust emissions over time. 

Approach

Heavy vehicle chassis emissions data is collected 

by West Virginia University (WVU) in support of the 

Department of Energy National Renewable Energy 

Laboratory (NREL) Truck and Bus Evaluation 

projects. The chassis emissions data is stored in a 

separate database maintained by NREL's Alternative 

Fuel Data Center. Results from this database are 

useful for examining trends in diesel emissions and 

comparisons of diesel and alternative fuel emissions 

[1-3]. Previous projects have often included a 

detailed fuel analysis and this analysis is required for 

all future projects. The results of these fuel analyses 

are archived in the Liquid Fuel Property Database, a 

web-based listing of fuels used in APBF research 

projects. Users can search the database and generate 

search results that can be imported into common 

desktop software projects for further analysis. 

Results

The Fuel Property Database includes various 

chemical, physical, and operability property data, in 

addition to environmental health and safety 

information. The database is accessible at http://

www.ott.doe.gov/fuelprops/. The main users of the 

database are technical experts involved in diesel fuel 

and emissions research.

The database is designed to allow the user to 

tailor a search to their need by selecting from a list of 

fuels and properties (Figure 1). The database allows 

the user to select one or more fuels and associated 

properties from these lists. The user can select SI or 

English units for the fuel properties. Optional 

display fields include the test method used in the 

analysis, the literature reference for the fuel, and a 

brief description of the fuel. An alphabetical 

glossary of the key terms is included to facilitate use 

of the database by novice users (Figure 2).

The database is linked to chassis emissions 

provided in support of the NREL Truck and Bus 

Evaluation projects. The user can select from a list of 

fuels and the database returns the chassis emissions 

data for that fuel (Figure 3). The search results 

provide information on the vehicle and engine (i.e. 

Figure 1. Fuel Property Database Selection Page, 

Includes Pull-Down Lists of Fuels and 

Properties
Fuels for Advanced CIDI Engines FY 2002 Progress Report

80

model year, type of vehicle, engine manufacturer, 

aftertreatment), chassis test cycle, the date the testing 

was performed, and the emissions results for the 

testing. 

The chassis emission data in the Fuel Property 

Database can be utilized to determine the 

deterioration of emissions over time. For example, 

the emissions control diesel fuel (EC-Diesel) project 

is a government-industry project to evaluate the use 

of ULSD and diesel particle filters in several diesel 

fleets in the southern California area. Emission 

testing in the EC-Diesel project was conducted by 

WVU at the start of the project and twelve months 

later, at the completion of the project. Fuel analyses 

were performed for the fuels used in the project and 

are available in the Fuel Property Database. The 

associated emissions data can be used to examine the 

particulate matter (PM) emission deterioration over 

the twelve-month project for a subset of vehicles. 

Five Ralphs grocery vehicles were operated on 

California Air Resources Board (CARB) diesel fuel 

for the duration of the EC-Diesel project. Emissions 

test results were extracted from the Fuel Property 

Database and analyzed. Table 1 shows the PM 

emissions results at the start and end of the test 

project for these five vehicles. Over the twelvemonth period, the PM emissions increased by a 

factor of two, showing significant deterioration as a 

function of time. 

The fuel properties from the CARB diesel can be 

extracted from the database to determine if a 

significant change in fuel properties may be 

responsible for the change in PM emissions. Table 2 

compares the CARB diesel fuel used for emission 

testing at the start and end of the EC-Diesel project. 

No significant property changes were recorded, 

indicating that the change in PM emissions is not a 

result of changing fuel properties throughout the 

project.

Conclusions

The Fuel Property Database provides a single 

location for properties of fuels used in support of 

APBF research projects. Fuel properties are archived 

in a user-friendly, web searchable database. In 

addition to fuel property information, the Fuel 

Property Database contains chassis emission data 

from heavy-duty vehicles using many of the fuels in 

the database, including vehicle and engine 

configurations, test cycles, test date, and regulated 

emissions results. The Fuel Property Database 

provides a single site with voluminous information 

on diesel fuels and chassis emissions data associated 

with these fuels and will continue to be a valuable 

resource in support of APBF projects. 

Figure 2. Glossary with Short Descriptions of Test 

Methods Referenced in Database Search Page

Table 1. Initial and Final Emissions of CARB Diesel 

Fueled Grocery Trucks from EC-Diesel Study 

Vehicle Date 

(Round 1)

PM, 

g/mi 

(Round 2)

Date 

(Round 2)

PM, g/mi 

(Round 2)

5915 2/11/2000 0.199 2/13/2001 0.368

5917 1/19/2000 0.146 2/16/2001 0.39

5918 3/9/2000 0.24 3/22/2001 0.66

5919 1/17/2000 0.208 3/27/2001 0.555

5920 1/15/2000 0.192 3/26/2001 0.555

Figure 3. Search Results of Chassis Emissions Data Page
Fuels for Advanced CIDI Engines FY 2002 Progress Report

81

References

1. LeTavec, C., Uihlein, J., Segal, J., Vertin, K., "ECDiesel Technology Validation Program Interim 

Report", SAE Technical Paper No. 2000-01-1854, 

2000.

2. LeTavec, C., Uihlein, J., Vertin, K., Chatterjee, S., 

Wayne, S., Clark, N., Gautam, M., Thompson, G., 

Lyons, D., Hallstrom, K., Chandler, K., Coburn, 

T., "Year-Long Evaluation of Trucks and Buses 

Equipped with Passive Diesel Particulate Filters", 

SAE Technical Paper No. 2002-01-0433.

3. Chandler, K., Norton, P., Clark, N., Dart's LNG 

Bus Fleet, Final Data Report, National Renewable 

Energy Laboratory, Golden, CO, 2000.

Table 2. Fuel Properties for CARB Diesel Fuel Used in 

the EC-Diesel Project

Property

ASTM 

Test 

Method

Units

CARB Diesel Fuel

 Projections

Initial 

Testing

Final 

Testing

Density D4052 kg/m3 844.5 84317

API Gravity D27 oAPI 36 36

Distillation (IBP) D86 oC 177.6 184.1

Distillation (50%) D86 o

C 274.1 269.5

Distillation (90%) D86 oC 328.2 328.4

Distillation (EP) D86 oC 351.6 351.4

Cetane Number D613 -- 54.1 51.4

Sulfur D5453 ppm 121.1 114.5

Olefins D1319 vol % 3.4 1.7

Saturates D1319 vol % 72.8 78.3

Aromatics D1319 vol % 23.8 20

Total Aromatics D5186 wt % 22.5 16.1

 Polyaromatics D5186 wt % 4.1 3.78

Heat of Combustion 

(

*

HHV)

D240 MJ/kg 45.74 45.64

Heat of Combustion 

(

*

LHV)

D240 MJ/kg 42.89 42.76

Flashpoint D93 oC 71.7 70

Cloud Point D2500 oC -9 -12

Pour Point D97 oC -12 -15

*

HHV = Higher Heating Value

*

LHV = Lower Heating Value
Fuels for Advanced CIDI Engines FY 2002 Progress Report

82

D. Isotopic Tracing of Fuel Components in Emissions from Diesel Engines Using 

Accelerator Mass Spectrometry

Bruce A. Buchholz (Primary Contact)

Center for Accelerator Mass Spectrometry, L397

Lawrence Livermore National Laboratory

P.O. Box 808

Livermore, CA 94551

(925) 422-1739, fax: (925) 423-7884, e-mail: buchholz2@llnl.gov

Charles J. Mueller

Combustion Research Facility

Sandia National Laboratories

Livermore, CA 94551

DOE Technology Development Manager: John Garbak 

(202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

A. Fuel Processing Effects on Engine Emissions and Efficiency

Tasks

2. Fuel & Lubrication Properties - Engine-Out Emissions

Objectives

• Determine contribution of specific carbon atoms in fuel components and oxygenates to certain 

emission products.

• Separate volatile and non-volatile fractions of soot.

• Test the effects of fuel molecular structure on combustion product distribution.

• Produce data to validate combustion modeling.

Approach

• Selectively label specific carbon atoms in dibutyl maleate to achieve a carbon-14 (14C) contemporary 

fuel.

• Analyze carbon isotope content of all fuel components and lubrication oil.

• Collect soot and combustion gas from skip fired 1.7 liter optical engine. Complete isotopic analyses of 

soot and determine contributions from available carbon sources.

Accomplishments

• Reconfigured filter assembly and gas collection to improve throughput and cleaning of system.

• Completed preliminary tests to determine engine operation conditions for loading filters with sufficient 

soot for isotopic analyses. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

83

• Reduced and nearly eliminated lubrication oil leakage as contributor of carbon emissions from test 

engine.

• Completed experiments tracing the fate of different maleate-derived carbon atoms from dibutyl 

maleate fuel to emissions products.

Future Directions

• Determine contributions of major fuel components to soot production and test selected oxygenates 

(e.g., tripropylene-glycol monomethyl ether).

• Apply tracing technique to measure contribution of aromatics and cyclo-alkanes to emission products 

in diesel engines. 

• Collect gaseous emissions and separate major components.

• Obtain carbon-14 labeled lube oil and run it in a conventional diesel engine. Determine contribution of 

lube oil to soot and carbon dioxide (CO2) emissions.

• Apply tracing techniques to homogeneously charged compression ignition engines.

Introduction

Accelerator mass spectrometry (AMS) is an 

isotope-ratio measurement technique developed in 

the late 1970s for tracing long-lived radioisotopes 

(e.g., 14C half life = 5760 y). The technique counts 

individual nuclei rather than waiting for their 

radioactive decay, allowing measurement of more 

than 100 low-level 14C samples per day (Vogel et al, 

1995; Buchholz et al, 2002). 

The contemporary quantity of 14C in living 

things (14C/C = 1.2x10-12 or 110 femtomole [fmol] 

14C/ g C) is highly elevated compared to the quantity 

of 14C in petroleum-derived products. This isotopic 

elevation is sufficient to trace the fate of bio-derived 

fuel components in the emissions of an engine 

without the use of radioactive materials. Another 

approach is to purchase 14C-labeled material (e.g., 

dibutyl maleate (DBM)) and dilute it with petroleumderived material to yield a 14C concentration similar 

to a bio-derived fuel. In each case, the virtual 

absence of 14C in petroleum based fuels gives a very 

low 14C background that makes this approach to 

tracing fuel components practical. 

Regulatory pressure to significantly reduce the 

particulate emissions from diesel engines is driving 

research into understanding mechanisms of soot 

formation. If mechanisms are understood, then 

combustion modeling can be used to evaluate 

possible changes in fuel formulation and suggest 

possible fuel components that can improve 

combustion and reduce particulate matter (PM) 

emissions. The combustion paradigm assumes that 

large molecules break down into small components 

and then build up again during soot formation. AMS 

allows us to label specific carbon atoms in fuel 

components, including oxygenates, trace the carbon 

atoms, and directly measure how fuel molecular 

structure affects emissions.

Volatile and non-volatile organic fractions (VOF, 

NVOF) in the PM can be further separated. The 

VOF of the PM can be oxidized with catalysts in the 

exhaust stream to further decrease PM. The 

effectiveness of exhaust stream catalysts to oxidize 

products from tracer fuel components can be 

monitored through AMS measurement of carbon in 

PM.

Approach

The 14C concentration of all fuel components and 

the lubrication oil were checked by AMS and 

confirmed to be of petroleum origin (14C/C ratios 

~10-15). Test fuels containing 88% DBM, 7% nhexadecane (NHD) and 5% ethylhexyl nitrate (EHN) 

were spiked with DBM containing 14C labels in 

different positions in the molecule to obtain fuel 

containing 80-90 fmol 14C/ g C, approximately 70-

80% the 14C found in living things (see Figure 1). 

The high concentration of DBM in the fuel was 

selected to study the combustion of the oxygenated 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

84

hydrocarbon without the complication of high 

dilution in a conventional diesel fuel. Although the 

optical features of the engine are not discussed here, 

combustion of this fuel blend has been examined in 

detail at the Sandia National Laboratory (Mueller and 

Martin, 2002; Mueller, 2002).

Pre-combusted quartz filters were loaded with 

PM drawn from the exhaust manifold of a moderntechnology, 4-stroke, heavy-duty direct injection (DI) 

diesel engine that has been modified to provide 

extensive optical access into the combustion 

chamber. Injection timing was optimized such that 

the engine produced maximum gross indicated 

torque. The engine operated at 1200-revolutions per 

minute and moderate load (8.00 bar gross indicated 

mean effective pressure). Typical optical engine runs 

in skip fire mode (fire every 12th cycle) utilized 48-

84 fires to deposit sufficient soot for isotopic 

analysis.

Some filters were baked at 320o

C for 2 hours to 

remove the VOF soot and unburned lubrication oil 

deposited on the filters during non-fired cycles. The 

remaining carbon on the filters was assumed to be 

NVOF. The procedure was developed using National 

Institute of Standards and Technology standard 

reference material 2975 diesel soot to obtain 

consistent isotope ratios and mass fraction of the 

NVOF. Switching to a poly-isobutylene based 

lubrication oil that cracks to butylene below 300°C 

has significantly improved removal of unburned lube 

oil from filters (see Figure 2). Improvements in the 

oil control system of the engine have also decreased 

oil deposition and improved operations. 

Figure 1. Dibutyl maleate molecule with the 

different labeled carbon positions indicated 

with asterisks: A) 1,4 maleate, B) 2,3 

maleate, and C) 1-butyl. The symmetry of 

the molecule yields two chemically 

identical carbon atoms for each label. 

Figure 2. Mass of carbon deposited on motored only 

filters. Heating Filters E, H, and L to 320°C 

for 2 hours removed almost all carbon 

deposited from lube oil. Analyzing the total 

carbon on filters G, J, and N indicated that 

significant 14C -free carbon was deposited on 

filters during motored runs. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

85

Results

The 14C content of NVOF soot varied 

significantly with the position of the label within the 

DBM molecule (Figure 3). Virtually no14C appeared 

in the soot when the label was placed in the 1,4 

maleate position (double bond to an oxygen atom and 

single bond to another oxygen participating in the 

butyl ester structure [Figure 1a]). The 1,4 maleate 

carbon is completely converted to CO2. It is safe to 

assume that the carbon=oxygen (C=O) bond survives 

combustion. The partitioning of the oxygen in the 

ester bridge between the 1,4 maleate carbon or the 1-

butyl carbon will be determined in the coming 

months. 

DBM with the 14C label in the 2,3 maleate 

position (carbon-carbon double bond (Figure 1b)) 

produced soot with the same isotopic content as the 

fuel (Figure 3). Molecular fragments with carboncarbon double bonds are known soot building blocks 

(Curran, et al., 2001; Westbrook, 2002). The NHD, 

EHN, and butyl groups in DBM are primarily nalkane structures and likely to combust as typical 

diesel fuel. 

Conclusions

Selective labeling of specific carbon atoms in a 

fuel component allows examination of the molecular 

structure effects on the combustion process. It is 

clear that nearest neighbor atoms in DBM influence 

the formation of molecular fragments. The data 

collected here provide direct validation of chemical 

kinetic models. Completion of the [1-butyl 14C] 

DBM runs will likely produce soot with a 14C 

content between the two maleates, providing 

information on partitioning of the oxygen in the ester 

bridge in DBM. Data are applicable to fuel design 

and provide information on the types of fuel 

structures that best reduce formation of PM. 

References

1. Buchholz, B. A., Cheng, A.S., Dibble, R. W., 

Mueller, C. J., Martin, G. C. (2002) Isotopic 

Tracing of Fuel Component Carbon in the 

 Emissions From Diesel Engines. SAE Technical 

Paper 2002-01-1942.

2. Curran, H. J., Fisher, E. M., Glaude, P.-A., 

Marinov, N. M., Pitz, W. J., Westbrook C. K., 

Layton D. W., Flynn, P. F., Durrett, R. P., zur 

Loye, A. O., Akinyemi, O. C., Dryer, F. L. (2001) 

Detailed Chemical Kinetic Modeling of Diesel 

Combustion with Oxygenated Fuels. SAE 

Technical Paper 2001-01-0653.

3. Mueller, C.J. and Martin, G. C. (2002) Effects of 

Oxygenated Compounds on Combustion and Soot 

Evolution in a DI Diesel Engine: Direct 

Luminosity Imaging. SAE Paper 2002-01-1631.

4. Mueller, C. J. (2002) Oxygenated Diesel Fuel 

Research at Sandia National Laboratories. 

Section 5 Report A, this report.

5. Vogel, J. S., Turtletaub, K. W., Finkel, R., Nelson, 

D. E. (1995) Accelerator Mass Spectrometry - 

Isotope Quantification at Attomole Sensitivity. 

Anal. Chem. 67, 353-9A.

Figure 3. Concentration of 14C in fuel and NVOF soot 

collected from [1,4 maleate 14C] DBM 

(Figure 1A) and [2,3 maleate 14C] DBM 

(Figure 1B). The NVOF soot collected with 

the 1,4 maleate label was essentially 14C free 

while the 2,3 maleate label produced soot 

with the isotope content of the fuel. 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

86

6. Westbrook, C. (2002) Diesel Fuel Combustion 

Modeling. Section 6 Report A, this report.

FY 2002 Presentations

1. Bruce Buchholz, Chuck Mueller, and Glen 

Martin. Isotopic Tracing of Fuel Components in 

Particulate Emissions from Diesel Engines Using 

Accelerator Mass Spectrometry. DOE 2002 

Review of OTT CIDI Engine Combustion 

Emission Control, & Fuels R&D National 

Laboratory Program, Argonne, IL, May 14-16, 

2002.

2. Bruce A. Buchholz, A.S. (Ed) Cheng, Robert W. 

Dibble, Charles J. Mueller and Glen C. Martin. 

Isotopic Tracing of Fuel Component Carbon in the 

Emissions from Diesel Engines. DOE & SAE 

Future Car Congress, Arlington, VA, June 3-5, 

2002.

3. Bruce Buchholz and Charles J. Mueller. Isotopic 

Tracing of Fuel Components in Particulate 

Emissions from Diesel Engines Using Accelerator 

Mass Spectrometry. PDVSA/CITGO-Hosted 

Transportation Panel Meeting, Tulsa, OK, June 

20, 2002.

4. Bruce A. Buchholz, Charles J. Mueller, Glen C. 

Martin, A.S. (Ed) Cheng and Robert W. Dibble. 

Tracing Stuff. Ninth International Conference on 

Accelerator Mass Spectrometry, Nagoya, Japan, 

September 9-12, 2002.

5. Buchholz, B.A., Cheng, A.S., Dibble, R. W., 

Mueller, C. J., Martin, G. C. (2002) Isotopic 

Tracing of Fuel Component Carbon in the 

Emissions From Diesel Engines. SAE Technical 

Paper 2002-01-1942.
Fuels for Advanced CIDI Engines FY 2002 Progress Report

87

E. Performance and Properties of Renewable Diesel Fuels

Robert McCormick (Primary Contact), Shawn Whitacre, Wendy Clark, David Johnson, Shaine Tyson

National Renewable Energy Laboratory

1617 Cole Boulevard Advanced Petroleum Based Fuels-Diesel Emissions Control

Golden, CO 80401

(303) 275-4432, fax: (303) 275-4415, e-mail: robert_mccormick@nrel.gov

DOE Technology Development Managers: 

John Garbak: (202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Steve Goguen: (202) 586-8044, fax: (202) 586-1600, e-mail: Stephen.Goguen@ee.doe.gov

Gerson Santos-Leon: (202) 586-1707, fax: (202) 586-9815, e-mail: Gerson.Santos-Leon@ee.doe.gov

Kevin Stork: (202) 586-8306, fax: (202) 586-2476, e-mail: Kevin.Stork@ee.doe.gov

Main Subcontractors and Industrial Partners: AAE Technologies, Inc., Arlington, Virginia, Pure 

Energy Corporation, Paramus, New Jersey, Southwest Research Institute, San Antonio, Texas

This project addresses the following DOE R&D Plan barriers and tasks:

Barriers

 A. Fuel Property Effects on Engine Emissions and Efficiency

Tasks

1. Screening

2. Fuel & Lubricant Properties - Engine-Pit Emissions

Objectives

• Develop a multi-year plan for research & development (R&D) to overcome technical barriers to 

increased utilization of renewable fuels blended into advanced petroleum-based fuels

• Conduct an assessment of technical barriers to increased ethanol use in diesel, including acquisition of 

fuel property, emissions, and performance data

• Perform an analysis of the potential for using ethanol as a feedstock for producing more desirable 

diesel blending components

• Identify other potential renewable diesel blending components that could be produced from 

agricultural and waste products

Approach

• Analyze the potential for diesel fuel produced from renewable resources to displace petroleum diesel

• Acquire data on the performance properties of renewable fuels blended with petroleum-based fuels

• Measure emissions and stability for ethanol-diesel blends

• Review literature and information provided by stakeholders on performance of ethanol-diesel blends, 

ethanol conversion chemistry, technical status of biodiesel, and potential for additional renewable 

diesel options
Fuels for Advanced CIDI Engines FY 2002 Progress Report

88

Accomplishments

• Prepared a strategic plan for renewable diesel development

• Identified ethyl levulinate as a potentially high-quality, low-cost renewable diesel blending component

• Collected fuel property data for blends of ethanol, biodiesel, and ethyl levulinate with conventional 

and ultra-low sulfur diesel

• Assessed the technical barriers to use and commercialization of ethanol-diesel blends and issued a 

summary report

• Completed an analysis of renewable diesel blending components that could be prepared using ethanol 

as a feedstock

• Prepared a multi-year plan for R&D of renewable diesel blending components, based on a common 

fuel development pathway

Future Directions

• Investigate the causes of increased oxides of nitrogen (NOx) emissions from biodiesel using incylinder pressure measurements and instrumented injectors

• Understand how to ensure biodiesel oxidative stability

• Perform R&D to address fuel injection equipment manufacturer issues with biodiesel

• Determine measures required to address the flammability hazards posed by the reduced flash point and 

increased vapor pressure of ethanol-diesel blends

• Obtain more detailed emissions data on ethanol-diesel blends, including emissions of toxic compounds

• Perform more detailed studies of fuel-engine interaction and fuel properties for ethyl levulinate blends 

with diesel fuel

• Assess R&D needs for Fischer-Tropsch (FT)-diesel derived from biomass

Introduction

Development of renewable diesel blending 

components is desirable in order to displace imported 

petroleum and to reduce emissions of global 

warming gases. Many of these fuels contain oxygen 

and therefore offer particulate matter (PM) emission 

reduction benefits for diesel vehicles, relative to 

conventional diesel. This project covers the 

development of strategic and R&D plans for 

renewable diesel fuels, along with assessments of the 

current technical status of these fuels. The results of 

these assessments along with fuel property data and 

the most important aspects of the R&D plan are 

discussed below. 

A strategic plan for renewable diesel 

development was prepared that identified biodiesel 

and renewable-based FT diesel as the highest priority 

renewable diesel fuels. These fuels are strategic 

because of their potential to displace billions of 

gallons of imported petroleum diesel and the high 

level of development of these technologies both in 

terms of fuel production and fuel use. Ethanol diesel 

blends are also important but have a much smaller 

petroleum displacement potential. Other fuels are at 

a basic R&D level but may have the potential to 

become strategic in the near to medium term. Longer 

term R&D should be directed at renewable fuels for 

advanced combustion concepts such as homogeneous 

charge compression ignition.

Approach

Information was collected from a variety of 

sources and evaluated to assess the technical status of 

renewable diesel fuels. Fuel property data, including 

American Society for Testing and Materials (ASTM) 

D975 properties as well as additional cold flow, 

lubricity, and vapor pressure properties were 

acquired under a subcontract with Southwest 

Research Institute. Data on ethanol-diesel emissions 

and blend formulation were obtained under a 

subcontract with Pure Energy Corporation (PEC).
Fuels for Advanced CIDI Engines FY 2002 Progress Report

89

Results

Biodiesel

Biodiesel is produced from various agricultural 

and waste fats and oils and consists of the methyl 

esters of fatty acids. Biodiesel is typically used as a 

20% blend in conventional diesel but lower blending 

levels have recently been considered. Consequently 

several low biodiesel content blends were examined. 

It was found that 2% biodiesel could improve the 

lubricity of conventional and ultra-low sulfur diesels 

(scuffing load ball on cylinder lubricity evaluator 

[SLBOCLE]>4000 grams and high frequency 

reciprocating rig [HFRR]<0.25 millimeter), while up 

to 4% biodiesel had no impact on cloud point, pour 

point, or cold filter plugging point. Previous studies 

suggest that there is no measurable change in 

emissions for biodiesel blends at these levels. Fuel 

utilization R&D issues remain for biodiesel 

including:

• Cause and abatement of increased NOx

emissions at higher blend levels

• Understanding and ensuring oxidative 

stability

• Ensuring compatibility with fuel injection 

equipment at higher blend levels

Ethanol-Diesel Blends

More recently there has been interest in blending 

ethanol into diesel fuel, so called "e-diesel". The 

limited solubility of ethanol requires the inclusion of 

cosolvent or microemulsifier additives for blend 

stability, especially in the presence of water. Cetane 

enhancing additives are also required because of the 

low cetane number of ethanol. Ethanol also imparts 

a low flashpoint to the diesel fuel, a fact that is likely 

to limit the market for this fuel. An assessment of the 

technical barriers to commercialization of e-diesel 

revealed that the main technical barriers are:

• Low flashpoint. E-diesel cannot be safely 

handled like conventional diesel but must be 

handled like gasoline. The fuel tank vapor 

space is also likely to be flammable. This 

may necessitate some modifications to 

storage and handling equipment, as well as 

vehicle fuel systems. 

• Obtaining engine original equipment 

manufacturer warranty acceptance. At 

present engine manufacturers will not 

warrant their engines for use with e-diesel 

because of concerns about safety and 

liability, as well as materials and component 

incompatibility. 

• Environmental Protection Agency (EPA) 

fuel registration requirements. As a nonbaseline diesel fuel, e-diesel will be required 

to undergo Tier 1 and Tier 2 emission and 

health effects testing.

• Stability. The low temperature and storage 

stability of e-diesel, as well as water 

tolerance of these blends, needs to be 

quantified.

Figure 1 presents data on the cloud point, cold 

filter plugging point, and flash point of ethanol diesel 

blends. At 2 and 4 volume percent ethanol there was 

no change in cold flow properties and only a small 

depression in flash point. At these low blend levels 

the fuel blend behaves as a solution rather than as an 

emulsion. When 2000 parts per million (ppm) water, 

was added to the 2 and 4% blends, the cloud point 

increased to -5oC (not shown in figure). The fuel 

grade ethanol used for blending contained 4400 ppm 

water. Identical behavior was observed for 2% 

ethanol blended with an ultra-low sulfur diesel 

Figure 1. Results of Cloud Point (ASTM D2500), Cold 

Filter Plugging Point (ASTM D6371) and 

Flashpoint (ASTM D93) Determination for 

Various Ethanol-Diesel Blends
Fuels for Advanced CIDI Engines FY 2002 Progress Report

90

employed in the Advanced Petroleum Based FuelsDiesel Emissions Control project. At 10% ethanol 

the flashpoint is essentially the same as that of 

denatured ethanol. The cloud point has increased to 

9oC, but the cold filter plugging point is the same as 

that of the baseline diesel fuel. This indicates that the 

high cloud point is caused by the formation of liquid 

micelles large enough to be observed in the cloud 

point apparatus but still able to flow through a fuel 

filter. Addition of 0.6% of a commercial emulsifier 

additive package reduced cloud point for the 10% 

blend by 6o

C and increased the flashpoint from 14 to 

24oC. After addition of 2000 ppm of water, both 

10% ethanol samples (with and without additives), 

exhibited phase separation at room temperature.

Testing performed by PEC has confirmed the 

impact of water on the stability of ethanol-diesel 

blends, showing room temperature phase separation 

for both 10 and 15% ethanol blended into a 

commercially obtained on-road pump diesel in the 

presence 1000 ppm water. Ongoing tests are 

examining the impact of PEC's Puranol additive on 

water tolerance. The PEC tests have also identified 

another stability related issue. Figure 2 shows cloud 

point data for 10% ethanol blended into a 

certification diesel and a pump diesel, including 

various percentages of their Puranol emulsifier 

additive. The certification diesel exhibits much 

lower cloud point (i.e. greater stability) than the 

pump diesel at all Puranol treat rates. PEC believes 

that the pump diesel contains a number of additional 

additives including detergents, corrosion inhibitors, 

anti-microbial agents, and de-emulsifying agents 

added to repel water. These additives may inhibit the 

Puranol additives' ability to form a stable emulsion of 

ethanol in diesel. This suggests that successful 

production of e-diesel will require the use of unadditized diesel blending stock.

Figure 3 shows lubricity measurements for ediesel samples via the HFRR and SLBOCLE 

methods. Addition of up to 10% ethanol had little 

impact on fuel lubricity, although the lubricity of the 

base certification diesel was not particularly high to 

begin with. Addition of 0.6% commercial emulsifier 

additive significantly improved the lubricity of the 

10% ethanol blend (decreased HFRR and increased 

SLBOCLE).

Under the Clean Diesel III program at Southwest 

Research Institute (SwRI) in San Antonio, Texas, 

Pure Energy Corporation performed an engine test 

project using e-diesel. Within the Clean Diesel III 

Consortium, SwRI has developed an engine capable 

of co-injecting mixtures of water and diesel fuel with 

real-time control of the water percentage. In addition 

to this capability, the Real-Time Water Injection 

(RTWI) engine is equipped with a high-pressure loop 

exhaust gas recirculation (EGR) system featuring a 

variable geometry turbocharger. The SwRI and Pure 

Energy team performed a series of tests to investigate 

the potential benefits of water injection plus 

Figure 2. Cloud Point Data (ASTM D2500) for 10% 

Ethanol in Certification Diesel and a Pump 

Diesel at Various Additive Treat Rates

Figure 3. Lubricity results for various ethanol-diesel 

blends via HFRR (ASTM D6079) and 

SLBOCLE (ASTM D6078) tests
Fuels for Advanced CIDI Engines FY 2002 Progress Report

91

oxygenated fuel on emissions from the RTWI engine. 

The test fuels were a baseline diesel fuel and a 10% 

ethanol blend (containing the Puranol additive). 

Testing was conducted over the 13-mode steady-state 

cycle. The concept of using a combination of EGR, 

RTWI, and oxygenated fuel for reduction of NOx and 

PM emissions is shown qualitatively in Figure 4. 

Application of EGR produces a reduction in NOx

from the baseline but a significant increase in PM. 

Injection of water causes a further reduction of NOx

and a reduction in PM. Use of oxygenated fuel 

reduces PM even farther. In this study, emissions of 

1.18 g/brake horsepower-hour (bhp-hr) NOx and 0.05 

g/bhp-hr PM were obtained for the e-diesel blend 

using both EGR and RTWI. Water was injected at a 

rate equivalent to 30% of the mass of fuel consumed 

over the test. At the same engine settings (timing, 

EGR, etc.) and water injection rate the baseline diesel 

fuel (containing no ethanol) produced 1.24 g/bhp-hr 

NOx and 0.07 g/bhp-hr PM. Thus in this test e-diesel 

produced a 5% reduction in NOx and 29% reduction 

in PM. Changes in emissions are significant at 95% 

confidence.

The flashpoint and tank flammability issues for 

e-diesel are the top priority for future R&D. A 

further priority is obtaining emissions data on toxic 

compounds. 

Oxygenates Produced from Ethanol

The flashpoint and stability issues evident for ediesel have spurred interest in the potential of using 

ethanol as a feedstock for production of a higher 

flashpoint renewable blending component. NREL 

has reviewed compounds that could be produced 

from ethanol along with a number of relevant fuel 

properties. Illustrative examples are shown in Table 

1. Diethyl ether is easily prepared from ethanol by 

dehydration over an acid catalyst and exhibits a very 

high cetane number (Bailey, et al., 1997). However, 

the flashpoint of this material is so low that it could 

never be considered as a diesel blending component. 

Diethyl carbonate can be prepared from ethanol and 

carbon monoxide, is highly soluble in diesel fuel, but 

exhibits a low flashpoint and high corrosivity 

(Natarajan, et al., 2001). 2-ethoxy ethyl ether 

exhibits interesting fuel properties and is highly 

soluble in diesel fuel (Natarajan, et al., 2001); 

however, it has been shown to exhibit unacceptable 

toxicological properties (Forest, 1995). The final 

entry in Table 1, diethoxy butane, could be produced 

entirely from ethanol by dehydration to produce 

diethyl ether followed by oxidative coupling to 

produce the desired product. A second potential 

synthesis route employs petroleum derived 

butadiene, but even in this case 50% of the carbon 

content of the product is renewable. While 

flashpoint is slightly below the 52o

C required for No. 

2 diesel, blends with diesel may exhibit an acceptable 

flashpoint. Cetane number is also high. Other 

compounds with good fuel properties are ethyl esters 

of fatty acids and ethyl n-alkyl ethers.

Ethyl Levulinate (EL)

Cellulosic waste materials such as paper sludge, 

sawmill waste, silage, and unrecyclable paper can be 

converted to a chemical called levulinic acid (4-oxopentanoic acid) via a thermochemical conversion 

process. Cellulose is converted to levulinic acid with 

Figure 4. Qualitative Emission Reduction Pathway 

for E-Diesel Testing Under the SwRI Clean 

Diesel III Program

Table 1. Properties of Ethanol and Potential Fuel 

Blending Components that Might Be Made from 

Ethanol

Flashpoint o

C

Cetane 

Number

Ethanol 13 8

Diethyl ether -40 >150

Diethyl carbonate 25 --

2-Ethoxy ethyl ether 54 86

Diethoxy butane 45 97
Fuels for Advanced CIDI Engines FY 2002 Progress Report

92

50% yield. Biofine, Inc. is developing this process 

with support from the New York State Energy 

Research and Development Authority and the DOE 

Office of Industrial Technologies, Forrest Products 

R&D program (Bozell, et al, 2000). Economic 

projections suggest that levulinic acid can be 

produced at a cost of from $0.04 to $0.10/lb. One 

use of levulinic acid is to produce ethyl levulinate 

(EL), the molecule shown in Figure 5. EL has been 

touted as a potential renewable diesel blendingcomponent (Rohde, 2001). Given the high flash 

point of EL (91o

C), the high lubricity imparted by the 

ester group, and the low projected cost of the starting 

material, measurement of the fuel properties of EL 

and EL-diesel blends were undertaken.

Some relevant properties of EL itself are listed in 

Table 2. The boiling point is in the normal diesel 

boiling range, and the high flashpoint indicates that 

the flammability problem that limits the market for ediesel will not apply to this blending component. 

Heating value is on the order of 8,000 British 

Thermal Units/pound (btu/lb), lower than that of a 

conventional diesel fuel and on the order of the 

heating value of ethanol. However, the density of EL 

is 25% higher than that of ethanol, so that a given 

volume of this oxygenate contains significantly more 

energy. The cetane number of EL is low, indicating 

that a cetane-treating additive would also be required 

at higher blending levels.

EL was blended into certification diesel at 5 and 

10 volume percent. Properties of these blends are 

listed in Table 3 and compared with those of the 

blending diesel certification fuel. At 5% and 10% 

EL there was no significant change in fuel properties 

with the exception of lubricity, which improved 

significantly. It is interesting to note that while the 

ignition quality testor (IQT) test predicts a cetane 

number of 5 for EL, the 5 and 10% EL blends 

exhibited no change, or even a small increase in 

cetane number as measured using ASTM D613. The 

results are encouraging for use of this material as a 

diesel blending component, but considerable 

additional data and testing are required. Specifically, 

it must be shown that EL-diesel blends are stable in 

the presence of water, and that EL is compatible with 

fuel system materials. Engine performance and 

emissions data are also required. 

Future Directions

The R&D plan for renewable diesel fuels 

identified a common fuel development pathway 

consisting of the following steps:

• Safety and Environmental Impacts

• Blend Stability

• Fuel Performance Properties

• Material Compatibility and Pump Wear

• Engine Performance and Regulated Pollutant 

Emissions

• Toxic Compound Emissions (Tier 1 Testing)

Table 2. Properties of Ethyl Levulinate 

(Case No. 5339-88-8)

Boiling Point, oC 206

Flashpoint, oC 91

Reid Vapor Pressure, psi <0.01

Higher Heating Value, btu/lb 11241

Lower Heating Value, btu/lb 10459 (88692 btu/gal)

Density, g/ml 1.016 (8.48 lb/gal)

Cetane Number (IQT) <10

Figure 5. Structural Representation of Ethyl Levulinate

Table 3. Properties of Ethyl Levulinate-Certification 

Diesel Blends

Cert Fuel 5% EL 10% EL

Flashpoint, oC 65 76 77

Cetane Number 47 48 52

Cloud Number, oC -17 -16 -14

Pour Point, oC -18 -24 -18

Density, g/ml 0.8440 0.8541 0.8625

Viscosity, mm2/s @ 40oC 2.610 2.527 2.470

Copper Corrosion 1A 1A 1B

SLBOCLE, g 4300 6000 5700

HFRR, mm 0.535 0.405 0.440
Fuels for Advanced CIDI Engines FY 2002 Progress Report

93

• Engine Durability

• EPA Registration and Demonstration Studies

The fuel development pathway defines what 

R&D is needed for a given fuel based on its position 

in the pathway. The R&D plan also identified a 

number of issues critical to the expanded use of 

biodiesel, biomass-derived FT-diesel and to the 

commercialization of ethanol-diesel blends. 

Additionally, new renewable diesel blending 

components that could be produced from either 

ethanol or from cellulosic biomass have been 

identified.

For biodiesel future R&D will focus on 

development of a quantitative and fundamental 

understanding of both the increased NOx emissions 

observed in many engines and oxidative instability of 

the fuel. An additional priority area for R&D is to 

understand the impact of biodiesel on fuel injection 

equipment performance, including materials 

compatibility and fuel pump durability. For ethanoldiesel blends the most important technical barriers 

are the low flashpoint of the fuel and the 

flammability of the tank vapor space. R&D to 

understand the measures that must be taken to safely 

use this fuel is being initiated late in fiscal year 2002 

and will be ongoing in 2003. A second priority area 

for e-diesel is to understand the impact of this fuel on 

fuel injection equipment performance. Research to 

investigate issues associated with use of biomass 

derived FT-diesel and the performance of new 

renewable diesel oxygenates will also be initiated.

References

1. Bailey, B., Eberhardt, J., Goguen, S., Erwin, J. 

"Diethyl Ether as a Renewable Diesel Fuel" SAE 

Technical Paper No. 972978, Society of 

Automotive Engineers, Warrendale, PA (1997).

2. Bozelle, J.J., Moens, L., Elliott, D.C., Wang, Y., 

Neuenscwander, G.G., Fitzpatrick, S.W., Bilski, 

R.J., Jarnefeld, J.L. "Production of Levulinic Acid 

and Use as a Platform Chemical for Derived 

Products" Resources, Conservation and Recycling 

28 227-239 (2000).

3. Forrest, W., "What's in a Name?" Environmental 

Health Perspectives 103 (12) Correspondence 

(1995).

4. Natarajan, M., Frame, E.A., Naegeli, D.W., 

Asmus, T., Clark, W., Garbak, J., Gonzalez, M.A., 

Piel, W., Wallace, J.P. "Oxygenates for Advanced 

Petroleum-Based Diesel Fuels: Part 1. Screening 

and Selection Methodology for the Oxygenates" 

SAE Technical Paper No. 2001-01-3631, Society 

of Automotive Engineers, Warrendale, PA (2001).

5. Rohde, P. "Northeast States Eyeing DieselAdditive Technology Using Cellulose Feedstock" 

New Fuels & Vehicles Report 22 (18) 1 (2001).

FY 2002 Publications and Presentations

1. McCormick, R.L., Parish, R. "Technical Barriers 

to the Use of Ethanol in Diesel Fuel" NREL/MP540-32674, November 2001.

2. McCormick, R.L. "Renewable Diesel: Technical 

Barriers to Fuel Use R&D" presented at National 

Biodiesel Board Meeting, November 6, 2001, 

Washington DC.

3. McCormick, R.L. "DOE Renewable Diesel 

Program" presented at National Biodiesel Board 

Research Brainstorming Meeting, January 23-24, 

2002, New Orleans, LA.

4. McCormick, R.L., Alvarez, J.R., Graboski, M.S., 

Tyson, K.S., Vertin, K. "Fuel Additive and 

Blending Approaches to Reducing NOx Emissions 

from Biodiesel" presented at National Biodiesel 

Board Research Brainstorming Meeting, January 

23-24, 2002, New Orleans, LA.

5. McCormick, R.L. "Renewable Fuels Initiative" 

presented to NREL Fuels Utilization Program 

Task Leaders Meeting, February 26, 2002.

6. McCormick, R.L. "Technical Barriers to the Use 

of Ethanol in Diesel Fuel" invited presentation at 

7th Annual National Ethanol Conference, 

February 27-March 1, 2002, San Diego, CA.

7. McCormick, R.L. "Renewable Diesel Fuels 

R&D" presented to NREL Technology Integration 
Fuels for Advanced CIDI Engines FY 2002 Progress Report

94

and Utilization Group Task Leaders Meeting, 

April 23, 2002.

8. McCormick, R.L., Alvarez, J.R., Graboski, M.S., 

Tyson, K.S., Vertin, K. "Fuel Additive and 

Blending Approaches to Reducing NOx Emissions 

from Biodiesel" presented at SAE Spring Fuels 

and Lubricants Meeting, May 2002, Reno, NV 

and SAE Technical Paper No. 2002-01-1658, 

Society of Automotive Engineers, Warrendale, PA 

(2002).
Fuels for Advanced CIDI Engines FY 2002 Progress Report

95

ACRONYMS AND ABBREVIATIONS

ADMM15 15% by Volume DMM blended in 

ALS Fuel

ADVISOR Advanced Vehicle Simulator

ALS Low Sulfur Diesel Fuel

AMS Accelerator Mass Spectrometry

ANOVA Analysis of Variance

APBF Advanced Petroleum Based Fuels

APBF-DEC Advanced Petroleum Based Fuels – 

Diesel Emissions Control

API American Petroleum Institute

ASTM American Society for Testing and 

Materials

ATDC After Top Dead Center

AVFL Advanced Vehicle Fuel Lubricant

bhp brake horsepower

bhp-hr brake horsepower-hour

BSFC Brake Specific Fuel Consumption

btu British Thermal Units

C Carbon, Centigrade

CA California Reference Diesel Fuel

CARB California Air Resources Board

CCV Closed Crankcase Ventilation

CFFS Consortium for Fossil Fuel Science

CH3OH Methanol

CH4 Methane

CIDI Compression Ignition Direct 

Injection

CO Carbon Monoxide

CO2 Carbon Dioxide

CVS Constant Volume Sampler

DBM Dibutyl Maleate

DECSE Diesel Emissions Control - Sulfur 

Effects

DF-2 EPA Certification Diesel Fuel

DFI/GC Direct Filter Injection/Gas 

Chromatography

DI Direct Injection

DMM Dimethoxymethane

DNPH Dinitrophenylhydrazine

DOC Diesel Oxidation Catalyst

DOE Department of Energy

DPF Diesel Particulate Filter

EC-Diesel Emissions Control Diesel fuel

ECS Emission Control System

EGR Exhaust Gas Recirculation

EHN Ethylhexyl Nitrate 

EL Ethyl Levulinate

EMA Engine Manufacturers Association

EPA Environmental Protection Agency

FE Fuel Economy

FEERC Fuels, Engines, and Emissions 

Research Center

fmol Femtomole

FT-100 Neat Fischer-Tropsch Fuel

FTIR Fourier Transform Infrared

FTP Federal Test Procedure

g grams

g/mi grams per mile

GC-MS Gas Chromatography-Mass 

Spectrometer

HC Hydrocarbon

HCCI Homogeneous Charge Compression 

Ignition

HD Heavy-Duty

HSDI High Speed Direct Injection

HFET Highway Fuel Economy Test

HFRR High Frequency Reciprocating Rig

hp horsepower

hr hour

IMEP Indicated Mean Effective Pressure

IQT Ignition Quality Testor

LPP Location of Peak Pressure

LPPm Location of Peak Pressure of Main 

Combustion

MECA Manufacturers of Emission Controls 

Association 

Mo Molybdenum

MY Model Year

N2O Nitrous Oxide 

NH3 Ammonia

NHD N-Hexadecane 

Ni Nickel

NO Nitric Oxide

NOx Oxides of Nitrogen

NREL National Renewable Energy 

Laboratory

NVOF Non-Volatile Organic Fraction

O Oxygen

o

C degrees Celsius

ORNL Oak Ridge National Laboratory

PAH Poly-cyclic Aromatic Hydrocarbon

PAS Photoacoustic Analyzer

Pd Palladium

PEC Pure Energy Corporation
Fuels for Advanced CIDI Engines FY 2002 Progress Report

96

PM Particulate Matter

ppm parts per million

Pt/W/ZrO2 Platinum/Tungsten/Zirconium 

Dioxide 

RPECS SwRI Rapid Prototyping 

Electronic Control System

RTWI Real-Time Water Injection

SCAQMD South Coast Air Quality 

Management District

SCF Supercritical Fluid

SCR Selective Catalytic Reduction

SER System Emissions Reduction

SLBOCLE Scuffing Load Ball On Cylinder 

Lubricity Evaluator

SUV Sports Utility Vehicle

SwRI Southwest Research Institute

THC Total Hydrocarbons

TPGME Tripropylene Glycol Monomethyl 

Ether

ULSD Ultra-Low Sulfur Diesel

US06 EPA Aggressive Driving Test Cycle

UV Ultraviolet

VGR Variable Geometry Turbine

VOF Volatile Organic Fraction

WVU West Virginia University

ZDDP Zinc Dialkyl-Dithiophosphate