UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2565 PLYMOUTH ROAD

ANN ARBOR, MI 48105-2498

 OFFICE OF

AIR AND RADIATION

Memorandum

Date: June 17, 2013

From: Jeff Herzog, Assessment and Standards Divisions, 

Office of Transportation and Air Quality

To: Docket # EPA-HQ-OAR-2011-0135

Subject: Meeting with Representatives of ASTM International on June 13, 2013, 

Regarding In-Use Quality Standards for E51-83

On June 13, 2013, staff from the Office of Transportation and Air Quality (OTAQ) met 

with representatives of ASTM International to discuss in-use fuel quality standards for E51-83 

(i.e. ethanol blends that contain 51 to 83 volume percent ethanol for use in flexible fuel vehicles). 

EPA provided presentation materials on the subject from a June 4, 2013, meeting with the 

California Air Resources Board to help frame the discussion (attached).

The following people participated in person at OTAQ’s facility in Ann Arbor Michigan:

ASTM: Colman Jones, General Motors

Charles Corr, Archer Daniels Midland 

EPA: Chris Brunner, Jeff Herzog, Paul Machiele, Tia Sutton

The following people participated by phone:

EPA: Paul Argyropoulos

Attachments: EPA presentation materials
E51-83 and E16-50

EPA briefing for the California Air Resources Board, June 4, 2013 
The E51-83 Problem

• No specific regulations for in-use E51-83 quality

• CAA 211(f) requires in-use fuels to be subsim to vehicle cert fuel

– FFV cert fuel historically made from denatured ethanol and the 

gasoline used for certification testing with butane trimming. Thus, 

blendstocks used in E51-83 must be subsim to gasoline 

– Regulatory requirements for FFV cert test fuel are proposed in Tier 3

• 2006 guidance that RFG/RBOB must be used to make E51-83 in RFG 

areas

• These have been the only two levers to constrain the blendstocks 

used to make E51-83 

– Prevent dumping of stuff like cheap waste solvents into E51-83

• We have stated that there are no provisions to allow the use of 

natural gasoline in E51-83

– Nevertheless, some ethanol blenders are ignoring the guidance, 

leading to market uncertainty

• Some refiners, terminals, blenders have been asking EPA to clarify 

standards for E51-83

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The E51-83 Problem (continued)

• The fuel & fuel additive (F&FA) registration and health effects testing 

requirements under part 79 have so far only been applied to gasoline and 

highway diesel fuel

• E51-83 is not considered gasoline, & therefore has not yet been subject to 

the F&FA registration and health effects testing under part 79

– Could designate as a transportation fuel in the future and require health 

effects testing

• No deposit control regs for E51-83 other than for the gasoline portion

– Low additive concentration may be exacerbating, rather than helping deposits

• In addition to providing insufficient assurance of E51-83 quality, the 

current situation is creating barriers to the expansion in E51-83

• E85 volatility has been too low for good vehicle startability/performance

– Likely leading to increased emissions and constraining manufacturer options in 

the context of LEVIII/Tier 3

– Allowing use of high-volatility natural gasoline and butane could help to meet 

the minimum ASTM volatility requirements while maximizing ethanol content 

– Use of cheap natural gasoline and butane could make E51-83 more 

economical, thereby furthering the goals of the RFS program 

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Potential for Natural Gasoline and Butane 

Blending to Lower High-Ethanol Blend Prices 

• Push for E30 to optimize use of octane benefits from ethanol

• Opportunity to increase ethanol use and reduce fuel costs through use of lowoctane / inexpensive natural gasoline as a blendstock

• Domestic natural gasoline supply expected to increase substantially with growth in 

natural gas and tight-oil production

– U.S. NGL production projected to increase ~45% from 2012 to 2017 (3,250 Mb/d by 2017) 

• Blending of natural gasoline and butane would help to meet minimum ASTM 

volatility specs while maximizing ethanol content of E51-83

– RVP of natural gasoline and butane substantially higher than RBOB/CBOB

• Price of natural gasoline & butane significantly less than RBOB/CBOB

– NG prices may fall as additional volumes are produced that do not have a clear home

• Much of the natural gasoline will be produced in the midwest coincident with 

ethanol production 

• We conducted a preliminary analysis of how natural gasoline and butane blending 

might help to reduce E51-83 & E30 prices

– Considered octane and distribution costs, but not potential additional natural gasoline & 

butane distribution infrastructure costs

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Preliminary Analysis of Potential Impacts on the Price of 

E51-83 & E30 from Natural Gasoline and Butane Blending 

Blendstock RVP RON MON (R+M)/2 Million BTU / 

BBL

BTU Blendstock /

BTU of CBOB

NGL 12 73 72 72.5 4.69 93%

EtOH 2.4 130 101.6 115.8 3.53 70%

CBOB 9 96 86 83.8 5.02 100%

RBOB 6 96 86 83.8 5.02 100%

nButane 51.6 92.5 88 90.25 4.00 80%

Blendstock Properties

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Preliminary Analysis of Potential Impacts on the Price of 

E51-83 & E30 from Natural Gasoline and Butane Blending 

(cont.) 

Blendstock Wholesale

$ / gallon

Blendstock price 

per gallon / CBOB 

price per gallon

Blenstock price per 

BTU / CBOB price 

per BTU

NGL 2.13 73% 79%

ETOH 2.52 83% 119%

CBOB 2.90 100% 100%

RBOB 2.98 103% 103%

nButane 1.46 50% 63%

Blendstock Wholesale Price

-Does not include additional NGL & butane distribution infrastructure capital costs

- Ethanol price is for Chicago

- NGL and butane prices are for Mt. Belview

- CBOB and RBOB prices are for Gulf Coast

- All prices are for early March 2013

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Preliminary Analysis of Potential Impacts on the Price of 

E51-83 & E30 from Natural Gasoline and Butane Blending 

(cont.) 

Blend NGL % Butane % RVP Octane $ / gal BTU cost 

compared to 

E10

E10 - - 9 87 $2.92 100%

E30 24.5% - 9 90.6 $2.63 98%

E51 49% - 11.2 94.6 $2.33 95%

E51 27%* - 9 $2.50

E70 30% - 9 102.8 $2.40 103%

E80 18.8% 1.2% 9 107.4 $2.43 108%

E85 12.3% 2.7% 9 109.8 $2.44 111%

Ethanol Blend Wholesale Price

* CBOB is remainder of HC blendstock

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E51-83 Discussion in the Tier 3 Rule

• Requested comment on new regulatory provisions to 

ensure E51-83 quality while allowing use of natural 

gasoline, and butane/pentane as blendstocks

• Requested comment on removing requirement that 

gasoline portion contain a deposit control additive

– Would defer setting deposit control requirement for E51-

83 until sufficient data is available

• We are evaluating when it would be appropriate to 

designate E51-83 as a transportation fuel and require 

health effects testing under the F&FA program

• Discussed need to ensure that all fossil fuel blendstocks 

used to make E51-83 incur an obligation under RFS

– Anticipate follow-up action as part of RFS annual rules

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Two Options to Ensure E51-83 Quality

• Under Option 1, E51-83 producer would assume all 

responsibilities of a refiner

– Provides the most flexibility re blendstocks used

– However, the per-batch testing and other requirements would 

be impractical for most E51-83 blenders 

• Under Option 2, “E51-83 blender” would have minimal 

testing burden if they used only certified blendstocks

– Certified gasoline & BOBs (RFG/RBOB in RFG areas) 

– Denatured ethanol that meets requirements proposed in T3 rule

– Butane that meets existing requirements for downstream 

blending into gasoline 

– Pentane that meets requirements similar to those for butane

– Natural gasoline that has been certified by producer for use in 

E51-83

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Envisioned E51-83 Standards 

• Under Option 1, the E51-83 refiner would be 

subject to

– 10 ppm sulfur average, 50 or 80 sulfur cap (depending 

on what refinery-gate cap is finalized in T3)

– 0.20 benzene cap

– C, H, N, O, S

– Maximum RVP requirements for gasoline

– Minimum RVP requirements per ASTM

• Compliance demonstrated on per-batch basis via 

testing 

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Envisioned E51-83 Standards (continued) 

• Under Option 2, the E51-83 “blender” would comply by simply 

blending compliant blendstocks (ethanol, denaturant, gasoline, 

natural gasoline, etc.)

• Would be subject to

– 65 or 95 downstream sulfur cap (depending on what is finalized in T3)

– Anticipate that actual sulfur levels would typically be much lower and 

average at or below 10ppm

• Compliance with sulfur cap and other chemical composition 

requirements could be demonstrated by retaining PTDs for certified 

blendstocks used and other quality control requirements that apply 

to downstream parties

• Demonstration of compliance with envisioned RVP requirements an 

issue

– Evaluating the use of an RVP model in place of per-batch testing

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Blendstock Requirements for E51-83 

Blenders - Denatured Fuel Ethanol 

• Current sulfur cap for DFE is 30 ppm

• Tier 3 rule proposed

– 10 ppm sulfur cap

– Limiting denaturants to gasoline, BOBs, and natural gasoline

– Limiting denaturant concentration to max of 2.0 vol % 

(effectively 2.5% with rounding)

– Believe that proposed denaturant requirements would obviate 

the need for benzene, olefins, and aromatics specifications 

(result in levels similar those under CARB’s requirements)

– Requested comment on whether it is appropriate to adopt 

specifications on denaturants similar to CARB’s (10 ppm max S, 

0.06 v% Bz, 0.5 v% olefins, 1.7 v% aromatics) 

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Blendstock Requirements for E51-83 

Blenders – Butane & Pentane 

• Current sulfur cap for butane blended downstream of 

refiner is 30 ppm

• Tier 3 rule proposed a 10 ppm sulfur cap

• Proposed to maintain the other existing requirements

– Commercial grade butane: 95% pure, <=1.0 vol % olefins, 

<= 2.0 vol % aromatics, <=0.03 vol % benzene

– Non-commercial grade butane: <=10.0 vol % olefins, 

<= 2.0 vol% aromatics, <= 0.03 vol % benzene

– If non-commercial grade butane is used, a quality assurance 

program is required that includes periodic sampling and testing 

of butane from each manufacturer 

• Tier 3 rule proposed to establish similar requirements for 

downstream pentane blending 

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Blendstock Requirements for E51-83 

Blenders – Natural Gasoline 

• Producer of natural gasoline for use as an E51-83 

blendstock would be required to register and conduct 

per-batch tesing similar to requirements for gasoline 

refiner

• Producer would demonstrate compliance with 10 ppm 

sulfur cap, 0.20 vol % benzene cap, CHNOS

• Requested comment on need for other specifications 

(e.g., olefins, aromatics) and need to limit production 

sources (e.g., no drip gas)

• Producer would list RVP on PTD to facilitate blender 

compliance with RVP requirements through modeling

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Path Forward to Address Outstanding 

Issues re Natural Gasoline

• Attempting to get DOE/NREL/ORNL to support 

study of (Details in Appendix #1):

– Natural gasoline production, markets, distribution, 

prices

– In-use natural gasoline quality

– Impacts of natural gasoline on FFV emissions

– Development of RVP blending model to allow terminal 

blending without need for RVP testing

• Seeking input from auto manufacturers, fuel 

producers, and other stakeholders

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The E16-50 Problem

• EPA currently has no specific regulations for in-use E16-

50 quality

• Under the F&FA registration program, the gasoline 

family includes fuels with at least 50% clear gasoline

– Thus, E16-50 is logically subject to gasoline standards

• ~ 300 blender pumps and the number is growing

– Currently, such blenders should be treated as refiners but 

they are unaware

– Such blends are likely violating our standards on F&FA 

registration, RVP, detergents, other?

• Given DOE/USDA support for blender pumps, it makes 

dealing with them difficult

• EPA has been approached to approve a blender pump 

project

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E16-50 Discussion in the Tier 3 Rule

• Treat E16-50 as gasoline (as today), or amend regulations similar to 

the approach for E51-83

• Treating as gasoline would likely make use of blender pumps 

unworkable

– Per-batch gasoline quality requirements impractical

– In non-RFG areas, 1 psi waiver for <=E10 would mean that some E16-

50 blends would exceed 9 psi

• Treating as an alternative fuel could accommodate the use of 

blender pumps

– Would need to allow E16-50 blends to meet 10 psi

• Would need to continue to require that FFVs be certified using 10 psi fuel, so 

evap. emissions effect should be neutral

– All blendstocks used need to be certified upstream

– Would defer the question of health effects testing under the F&FA 

program for the time being

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Appendix #1

Potential Analytical Plan re the use of 

Natural Gasoline as an E51-83 Blendstock

EPA briefing for the California Air Resources Board, June 4, 2013 
Natural Gasoline Market Characterization

• Characterize how domestic natural gasoline production volumes are projected to increase in 

the future.

• What are the potential uses for the increased volume of natural gasoline? (refinery, heavy 

crude oil diluent, petrochemical, export, other)

• Where will natural gasoline be produced and what options are available to transport it to 

various markets?

– What additional transportation infrastructure will be needed?

• How might the ramp up in natural gasoline volume affect its price?

• To what extent would the use of natural gasoline as a blendstock in the manufacture of highlevel ethanol blends be a good market choice?

• Given other competing end-uses for natural gasoline, how much natural gasoline potentially 

might be available for use in high-level ethanol blends?

• What additional fuel distribution infrastructure would be needed to facilitate the use of 

naturual gasoline in high-level ethanol blends?

• How might the use of natural gasoline in high-level ethanol blends tend to reduce the BTUadjusted price of high-level ethanol blends compared to E10?

• What are the issues associated with segregating an existing pool of natural gasoline that 

would be suitable for use in high-level ethanol blends or performing additional processing to 

produce such a segregated pool that would meet necessary specifications for the 

downstream blending of high-level ethanol blends?

– How might the sulfur and benzene standards we establish for such a segregated natural 

gasoline pool impact feasibility and cost? (e.g., 10 ppm sulfur cap, 0.6 benzene cap)

• Would volatility limits for high-level ethanol blends of 9 psi need to limit the volatility of a 

segregated natural gasoline pool to allow for downstream blending?

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Natural Gasoline Quality Evaluation

• Characterize the chemical composition and physical 

properties of natural gasoline that might influence vehicle 

emissions and performance, and how these fuel 

parameters vary depending on the source of natural 

gasoline 

• Sample natural gasoline from the range of possible 

domestic sources

• Measure sulfur, benzene, aromatics (speciated?), chlorine, 

salts, metals, distillation, oxidation stability, wastes and 

other contamination, other? 

- How does quality vary depending on source? 

(well- crude vs. natural gas, fractionator, processor, 

refinery, drip gas). 

- How does quality vary by season?

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Vehicle Emission and Performance Test Program

• Based on consideration of the results from the natural gasoline quality evaluation, conduct exhaust emission 

testing on a range of ethanol blends varying ethanol, natural gasoline, and conventional gasoline composition. It 

is presumed that emissions sensitivity will also provide and assessment of driveability impacts. 

• Based on results of fuel survey, evaluate extent that certain fuel parameters in the natural gasoline test fuel 

blendstock need to be modified to reflect fuel standards that we might expect to finalize

– E.g., sulfur and benzene content in the test fuel blendstock should be limited to ensure that the concentration in the 

blended test fuel is no greater than might be seen in gasoline meeting the proposed Tier 3 specifications)

• Report test fuel characteristics: sulfur, benzene, distillation, aromatics, RON, MON, speciation, blend fraction

– Test at 75F and 20F

– Test for: NOx, NMOG, PM mass, CO2, methane, toxics, and full emissions speciation on a subset 

– 10 FFV test vehicles of high volume to reflect range in in-use FFV vehicles

– Ethanol blends of E10, E30, E51, E70, E83 made with two types of natural gasoline (trimmed with butane as 

necessary to the desired RVP) for 75F testing and one type of natural gasoline for 20F testing to compare to similar 

blends made with CBOB (not adjusted with butane)

– Target 9 RVP natural gasoline blends for 75F testing, 12 RVP natural gasoline blends for 20F testing (CBOB blends at 

whatever RVP results – just measure and report)

– Compare test results from ethanol blend fuel containing natural gasoline to results obtained using ethanol blend fuels 

formulated using CBOB

– Evaluate whether testing other than for exhaust emissions is needed

• Evaporative emissions?

• Additional testing needed to address performance impacts? DI, V/L

• Are there unique concerns that need to be addressed with respect to potential phase separation of ethanol blends made 

with natural gasoline?

– Fuel injector deposit control test using bench rig

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RVP Modeling and Validation

• Develop model to allow E51-83 blenders to 

demonstrate compliance with RVP requirements 

for finished fuel in place of per-batch RVP testing

- Assumes RVP of blend components is 

available to blender (natural gasoline, CBOB. 

RBOB, RFG, CG, butane, pentane, denatured 

fuel ethanol)

• Validate results from model by RVP testing

• How many different samples of natural gasoline 

would need to be used in testing? 

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