On Tuesday the Environmental Protection Agency (EPA) finalized the Renewable Fuel Standard (RFS) volumetric requirements for 2013, cutting the goal for blending biofuels produced from cellulose by 99.4%. The original 2013 goal for cellulosic biofuel blending was 1 billion gallons, but the EPA was forced to lower this goal because cellulosic biofuel production has not increased fast enough to meet the blending goals envisioned when Congress passed RFS2 in 2007. The table below shows the final 2013 volume blending requirements and the blend percentage (the ratio of renewable fuel to petroleum-based gasoline and diesel consumed in the United States). The final row, Total Renewable Fuel, is inclusive of the three other fuel categories, so just under 10% of liquid transportation fuels in 2013 will come from renewable sources. It should be noted that the overall renewable fuel blending requirement for 2013 remains unchanged at 16.55 billion gallons.
Final 2013 RFS Standards
|Fuel Type||Volumes||Blend Percentage|
|Cellulosic biofuel||6.00 mill gal||0.004%|
|Biomass-based diesel||1.28 bill gal||1.13 %|
|Advanced biofuel||2.75 bill gal||1.62 %|
|Total Renewable fuel||16.55 bill gal||9.74 %|
Cellulosic biofuels are seen as the future of renewable fuels because they have lower lifecycle greenhouse gas (GHG) emissions and do not raise the same food vs. fuel questions that producing corn ethanol does. Cellulose is a polymer, or long chain of linked sugar molecules that is present in the cell walls of all green plants. This means that cellulosic biofuels can be made from waste products such as corn stalks, wood chips, or fast growing plants such as switch grass that require little or no inputs and can grow on marginal lands not suited for traditional agriculture. The sugars in cellulose are not as easy to free from the rest of the plant and the challenge has been scaling up processes to produce commercial volumes cost effectively. Only 20,000 gallons of cellulosic biofuels were produced in 2012, highlighting the difficulty of commercializing the technology.
Despite the low production volumes progress is being made scaling up cellulosic biofuel production. At the end of July Ineos Bio announced that their Indian River BioEnergy Center began producing cellulosic ethanol at commercial scale. The BioEnergy Center uses a gasification and fermentation process to convert cellulosic biomass to ethanol and renewable power. Inputs have included citrus, oak, pine, pallet wood waste, and the facility is permitted to use municipal solid waste (MSW). The plant is expected to produce eight million gallons per year of ethanol and six MW of renewable power. Ineos hopes to use the plant to demonstrate the viability of the technology at the Center with the goal of leasing it to others. The Energy Information Administration summarizes the outlook for cellulosic biofuel production through 2015 here.
In addition to the challenges of ramping up new technologies for cellulosic biofuel production there are political challenges as well. Demand for cellulosic biofuels is primarily created by the RFS2 mandates. The American Petroleum Institute has called on Congress to scrap the Renewable Fuel Standard (API Press Release) because volume blending requirements have not been adjusted to reflect reduced U.S. consumption of gasoline and diesel, and over concern that more than a 10% ethanol blend will harm vehicles. A discussion of the political issues around cellulosic and corn ethanol can be found in a recent Fortune article here.