The US Environmental Protection Agency (EPA) has proposed lowering the Renewable Fuel Standard (RFS) biofuel blending mandate to 15.21 billion gal. The Institute for Energy Research (IER) has explored the potential impacts of such a change in recent analysis.
However four years ago, when the EPA wrote its final rule on the RFS and released its Regulatory Impact Assessment in 2010, there was little doubt that biofuels produced lower greenhouse gas emissions than gasoline. The Impact Assessment predicted that corn ethanol’s emissions would be 17% lower than gasoline’s by 2022. By setting thresholds that require a certain amount of biofuels to be blended into transportation fuel each year, the EPA sought to cut emissions by 20% using corn ethanol and 50% using advanced biofuels.
More recently, a study by the Environmental Working Group (EWG) concluded that reducing the biofuel target would reduce emissions by the equivalent of taking 580 000 cars off the road.
However, a study conducted by Biotechnology Industry Corporation found that reducing the target would in face add greenhouse gas emissions equivalent to placing 5.9 million cars on the road. This latest research suggests that the impact of using biofuels over petroleum-based fuel is unclear, primarily due to uncertainties in modeling biofuel emissions associated with life cycle production and land use changes.
Land use considerations
The EWG report produced in May concluded that the EPA proposal to cut the 2014 RFS target by 1.4 billion gal. would actually lower US greenhouse gas emissions by 3 million t of carbon dioxide. EWG holds that previous estimates and models dramatically underestimate carbon dioxide emissions associated with land changes, plowing grasslands and wetlands to turn into corn fields for biofuel production, which release carbon locked up in trees and soil into the atmosphere. Therefore, EWG suggests that by taking the full lifecycle of biofuel production, transmission, and tailpipe emissions into account biofuels release more carbon dioxide into the air than gasoline.
In response to EWG’s study, a group of seven scientists conducted their own research and came to similar conclusions as the ones produced by the Biotechnology Industry Corporation. The reports suggested that EWG’s models both exaggerate the total amount of land that has been converted into corn ethanol production and overestimate the carbon released from such land changes. They therefore concluded that reducing the 2014 RFS mandate would increase greenhouse gas emissions.
IER has described this confusion over the effects of the RFS biofuels mandate as ‘a good reminder of the folly of mandates – politicians understand far less of the world than they think they do’.
Adapted from a report by Emma McAleavey.
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/02072014/the_folly_of_mandates_820/