Final RFS rule validates corn ethanol

By Susanne Retka Schill | January 04, 2010
Posted Feb. 3, 2010

New, highly-efficient corn ethanol plants are expected to meet the 20 percent greenhouse gas (GHG) threshold required for conventional biofuels used to meet the renewable fuels standard in the final rule for the RFS released Feb. 3, a big change from the proposed rule where corn ethanol was heavily penalized by the inclusion of indirect land use. U.S. EPA Administrator Lisa Jackson said at a Feb. 3 White House press conference that changes to the greenhouse gas (GHG) modeling found all classes of biofuels meet the RFS GHG reduction goals. "We listened to public comment and worked closely with the USDA," said EPA Administrator Lisa Jackson, noting there were three major areas that changed the GHG ratings for corn ethanol. "On crop productivity, the data we used was not right," she said, and when current yield information was incorporated the numbers changed. The EPA also changed the way it considered coproducts and the indirect land use modeling was broadened beyond the initial 40 nations to include 120 nations, which changed the numbers, she said.

Where corn ethanol and soy-based biodiesel fared badly in the proposed rule, which Jackson admitted constricted market investment, the final rule should give investors renewed confidence in biofuels. "Based on what we know now, including indirect land use change, there is no basis to exclude these fuels," Jackson said.

The good news for the ethanol industry is that EPA's final rule finds that production from highly-efficient, natural gas corn ethanol plants will meet greenhouse gas reduction targets of 20 percent, compared to the 2005 gasoline baseline. In the press conference, Jackson said those gallons can be applied to RFS targets above 15 billion gallon. Existing, less efficient corn ethanol plants will still be grandfathered in, and will be held to the 15 billion gallon cap. However, after the press conference, EPA issued a clarification that said: "Administrator Jackson misspoke on today's call. Corn ethanol, based on EPA's updated modeling, meets the 20 percent GHG reduction requirement qualifying it for use as a conventional biofuel - not an advanced biofuel, which must meet a 50 percent reduction requirement." [The original story written here was edited to reflect that correction.]

In releasing the final rule, the EPA said its GHG threshold determinations include an analysis of full lifecycle of various fuels, including emissions from international land use change. In addition to making multiple modifications to the models, the EPA also quantified the uncertainty associated with many components. "EPA is confident that its modeling of GHG emissions associated with international land use is comprehensive and provides a reasonable and scientifically robust basis for making threshold determinations," the background statement to the lifecycle analysis portion of the final rule says.

Based on the analysis EPA determined:

    Ethanol produced from corn starch at a new natural gas, biomass, or biogas-fired facility using advanced efficient technologies will meet the 20 percent GHG emission reduction threshold compared to the 2005 gasoline baseline
    Biobutanol from corn starch also meets the 20 percent threshold
    Ethanol from sugarcane complies with the applicable 50 percent reduction threshold for advanced biofuels
    For cellulosic ethanol and cellulosic diesel, the pathways modeled by EPA for feedstock and production technology would comply with the 60 percent GHG reduction threshold for cellulosic biofuel
    Similarly, biodiesel from soy oil also will meet the 50 percent GHG threshold.

In addition to the feedstocks and fuel pathways that were modeled in the development of the rule, the EPA mentions five categories of feedstock that are expected to have less or no indirect land use changes including:

    Crop residues such as corn stover, wheat straw, rice straw, citrus residues
    Forest material including eligible forest thinning and solid residue remaining from forest product production
    Secondary annual crops planted on existing crop land such as winter cover crops
    Separated food and yard waste including biogenic waste from food
    Perennial grasses including switchgrass and miscanthus

Other feedstocks were not sufficiently modeled, EPA said, but will be included in a rulemaking within six months. Among the crops named were grain sorghum ethanol, woody pulp ethanol and palm oil biodiesel. EPA is also establishing a process were biofuel producers or importers can petition the agency to consider a new fuel pathway for eligibility. "EPA will use the data supplied in the petition to evaluate whether the information for the fuel pathway, combined with information developed in this rulemaking for other fuel pathways, is sufficient to allow EPA to determine whether the new fuel pathway qualifies," the background to the rule says.

The final rule and supporting background and documents can be found on the EPA Web site at