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RFS Implementation & 

Lifecycle Analyses

Farm, Ranch, Rural Communities 

Meeting

February, 2009
Office of Transportation & Air Quality

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Renewable Fuels Standard

 Final rule signed April 9th

 Requires Growing Renewable Use 

 From 4 billion gallons per year beginning in 2006 to 7.5 billion 

gallons per year by 2012

 Renewable values based on volumetric energy content in comparison 

to corn ethanol

 Corn-ethanol: 1.0

 Cellulosic biomass ethanol: 2.5

 As specified in EPAct

 Biodiesel (alkyl esters): 1.5

 Renewable diesel: 1.7

 Biobutanol: 1.3

 Sought comment on life cycle energy, petroleum, GHG emissions

 Program officially started on September 1, 2007

 Passage of the Energy Independence and Security Act significantly

expanded volumes, extended the timeframes, and added GHG 

thresholds...
Office of Transportation & Air Quality

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EISA of 2007: New Challenges and Direction

 Volumes increase to 9 

Bgal/yr in 2008 –

escalating to 36 Bgal/year 

by 2022

 Establishes new

renewable fuel categories 

and eligibility 

requirements, including 

GHG reduction 

thresholds!

 Provides new waivers 

and paper credit 

provisions

 Includes new obligation 

for fuels

 Includes new studies and 

reports

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10.0

15.0

20.0

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30.0

35.0

40.0

20062007200820092010201120122013201420152016201720182019202020212022

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RFS1

RFS2

RFS2: Much Higher Volumes

Modifies Current RFS program beginning in 2008
Office of Transportation & Air Quality

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RFS2: Four Separate Volume Mandates
Office of Transportation & Air Quality

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Rulemaking Status

 FR Notice for 2008: Completed

 Volume changed from 5.4 to 9.0 bill gal

 Proposal is complete and awaiting OMB approval

 Also continuing to meet with various stakeholders 

(e.g. industry, academic experts, CA/EU, 

environmental organizations, federal and state 

agencies), particularly with regards to lifecycle 

analyses...
Office of Transportation & Air Quality

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Other Issues

 Ethanol Blendwall

 Cellulosic Production

 Cropland / Rangeland 

 Waivers
Office of Transportation & Air Quality

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EISA Requires Lifecycle Assessment

 Each fuel category required to meet mandated GHG performance 

thresholds (reduction compared to baseline petroleum fuel replaced)

 Conventional Biofuel (ethanol derived from corn starch) 

 Must meet 20% lifecycle GHG threshold

 Only applies to fuel produced in new facilities

 Advanced Biofuel

 Essentially anything but corn starch ethanol

 Includes cellulosic ethanol and biomass-based diesel

 Must meet a 50% lifecycle GHG threshold

 Biomass-Based Diesel

 E.g., Biodiesel, “renewable diesel” if fats and oils not co-processed with 

petroleum

 Must meet a 50% lifecycle GHG threshold

 20-50% still counts as renewable fuel

 Cellulosic Biofuel

 Renewable fuel produced from cellulose, hemicellulose, or lignin

 E.g., cellulosic ethanol, BTL diesel

 Must meet a 60% lifecycle GHG threshold

 EISA language permits EPA to adjust the lifecycle GHG thresholds by as 

much as 10%

 Baseline fuel for comparison is gasoline and diesel fuel in 2005
Office of Transportation & Air Quality

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Definition of Lifecycle GHG Emissions

‘‘(H) LIFECYCLE GREENHOUSE GAS EMISSIONS.—The 

term ‘lifecycle greenhouse gas emissions’ means the 

aggregate quantity of greenhouse gas emissions 

(including direct emissions and significant indirect 

emissions such as significant emissions from land use 

changes), as determined by the Administrator, related to 

the full fuel lifecycle, including all stages of fuel and 

feedstock production and distribution, from feedstock 

generation or extraction through the distribution and 

delivery and use of the finished fuel to the ultimate 

consumer, where the mass values for all greenhouse 

gases are adjusted to account for their relative global 

warming potential.
Office of Transportation & Air Quality

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Overview of What We Need

 Need to develop life cycle GHG values for each potential 

fuel and production pathway, for example:

 Corn ethanol (dry mill, wet mill, coal, natural gas, etc.)

 Biodiesel / Renewable Diesel

 Soybean oil

 Waste grease

 Cellulosic Ethanol (enzymatic, thermochemical)

 Agricultural residue (e.g., corn stover)

 Forest wastes

 Switchgrass / other energy crops

 Imports

 Sugarcane ethanol

 The components of the analysis are generally the same 

for all biofuels, but each has own set of assumptions and 

issues
Office of Transportation & Air Quality

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Methodology

 EISA definition requires the use of a number of models and tools

 Including direct and indirect impacts such as land use change 

requires analysis of markets

 Typical life cycle analysis tools are based on process modeling

 To capture market impacts need to use economic models

 Conducting our own process and emissions modeling as part of 

rulemaking

 Scenario Comparison: Run models with different volume scenarios to 

isolate the impact of specific fuel

 Consider change between baseline projected fuel volume in 2022 

(i.e., without RFS2) and projected RFS2 mandated volume.

 Held volumes of other fuels constant at RFS2 mandated levels

 For areas of uncertainty, we have tested our primary approach and key 

assumptions with sensitivity analyses and different methods
Office of Transportation & Air Quality

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EPA Lifecycle Analysis Uses Several Models
Office of Transportation & Air Quality

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Key Factors in Land Use Assessment

 This analysis has revealed which factors have the most 

significant impact on the final results

 What Type of Land is Converted?

 For example, historic satellite data suggests that in some countries significant 

amounts of forest would be converted to cropland

 However, we are looking at sensitivities around these assumptions that would 

show varying degrees of forestry impact

 Treatment of Time Related Land Use Changes?

 Land use change results in stream of emissions that are changing over time

 We need to define a life cycle GHG value that is applicable to all gallons 

across time

 We are looking at a range of approaches for treating the land use changes 

over time

 We are conducting additional sensitivity analyses around these 

factors
Office of Transportation & Air Quality

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International Agriculture & Land Use Change

 Questions we need to address in this analysis:

 How much land is converted internationally?

 What are the emissions trends from international crop 

production?

 Where does land use change occur?

 What types of land are converted?

 What are the GHG factors from that land conversion?

 How do we account for the time dimension of GHG 

releases?

 In order to address uncertainty around these factors, 

we are performing sensitivity analyses and 

examining two approaches
Office of Transportation & Air Quality

14 EPA Staff Deliberative Draft: Do not cite, quote, or distribute

Accounting for the Time Dimension of Land 

Conversion GHG Releases

 Land use change results in stream of emissions that are changing over time

 Need to define a life cycle GHG value that is applicable to all gallons across 

time

 Aspects to consider

• Length of program • Discount rate

Time

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Gasoline Baseline Biofuel w/o Land Use Biofuel Land Use

Land Converted

ILLUSTRATIVE 

EXAMPLE
Office of Transportation & Air Quality

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Biofuel Production Modeling

 Corn ethanol

 Working with USDA and industry

 Considering different configurations (fuel source, 

technologies, carbon capture)

 Cellulosic ethanol

 Looking at modeling by NREL & GREET that projects 

use of biomass lignin for process energy, enabling 

plants to sell electricity to the grid

 Offsets grid electricity production and results in GHG 

benefits

 Imported Sugarcane Ethanol Production

 Like cellulosic, can produce excess electricity from 

burning bagasse
Office of Transportation & Air Quality

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Petroleum Baseline

 We use updated version of GREET and EIA data

 Energy efficiency of refining and crude extraction 

(GREET)

 Assuming 2005 mix of crude

 Tar Sands

 Included Venezuela extra heavy and heavy crude

 Developed emissions factors for those crude types (not 

currently included in GREET)

 Also considering new DOE/NETL report

 Similar overall results within 2% of EPA estimates

 Also working to include energy sector impacts
Office of Transportation & Air Quality

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Summary and Next Steps

 In developing the lifecycle methodology, our approach has been to use the best 

models, tools, and resources available

 Using sensitivity analysis and examining multiple approaches to address key 

areas of uncertainty

 The notice of proposed rule-making (NPRM) provides an important opportunity 

for EPA to present our work and to seek comment on proposed approaches and 

alternative approaches

 Planning to hold workshops on lifecycle analysis following release of the 

NPRM

 Engage experts between proposal and final to ensure expert-level feedback

 Consulting EPA’s Science Advisory Board (SAB) 

 Plan to conduct formal external peer-reviews of key components

 This input, along with the additional analysis we will be conducting between now

and the final rule, will further improve our methodology

 Anticipate 3-5 year cycles for updating the analysis