Limits on supply of advanced biofuels will keep the US from meeting statutory requirements of the controversial Renewable Fuel Standard (RFS), concludes a study by the Government Accountability Office.
The RFS recently came under renewed criticism from oil and gas trade groups when the Environmental Protection Agency, on Nov. 23, published increased quotas for 2017 (OGJ Online, Nov. 23, 2016). Industry representatives say market and technological constraints make the quotas impracticable.
The GAO study responded to a request from a Senate Committee on Homeland Security and Governmental Affairs subcommittee.
It noted that expansion in supply of advanced biofuels is necessary to achievement of RFS targets because conventional biofuel supply has nearly reached the statutory peak of 15 billion gal/year.
Advanced biofuels reduce life-cycle greenhouse gas emissions by at least 50%. For conventional biofuels, mainly ethanol from cornstarch, the threshold is 20%.
From interviews with federal agencies and a meeting of experts convened with the National Academy of Sciences, the GAO said cost and other factors affecting advanced biofuels will “make it challenging to significantly increase production in the next 5-10 years.”
In 2015, production of advanced biofuels totaled 3.1 billion gal of ethanol-equivalent. The year’s statutory target was 5.5 billion gal, which increases yearly to 21 billion gal in 2022.
Limiting expansion potential, GAO said, are:
• The low price of fossil fuels relative to advanced biofuels.
• The high cost of converting cellulosic feedstock.
• The time and cost to bring a new technology to commercial-scale production.
• The time and cost to secure fuel certification and acceptance.
• Uncertainty about government policy.
• An underdeveloped feedstock supply chain.
Within the advanced biofuel category, the only subcategory that exceeded its 2015 target was biomass-based diesel. Output during the year totaled 1.5 billion gal against a goal of 1 billion gal. In addition, production of renewable diesel totaled about 300 million gal.
But growth within even these small subcategories faces limits.
“Experts agreed that expansion potential for these fuels is limited by the availability of feedstocks (fats and oils), for which there are competing uses,” the study noted. “For example, soybean oil is also used as a cooking oil.”
GAO also reported that federal research and development funding, about $1.1 billion during 2013-15, is shifting focus from cellulosic ethanol toward drop-in fuels, which are fully compatible with existing engines and distribution systems.