Special Report: How U.S. ethanol plants are allowed to pollute more than oil refineries

By Leah Douglas of Reuters. Excerpts:

"In 2007, the U.S. Congress mandated the blending of biofuels such as corn-based ethanol into gasoline. One of the top goals: reducing greenhouse gas emissions.

But today, the nation’s ethanol plants produce more than double the climate-damaging pollution, per gallon of fuel production capacity, than the nation’s oil refineries, according to a Reuters analysis of federal data.

The average ethanol plant chuffed out 1,187 metric tons of carbon emissions per million gallons of fuel capacity in 2020, the latest year data is available. The average oil refinery, by contrast, produced 533 metric tons of carbon.

The ethanol plants’ high emissions result in part from a history of industry-friendly federal regulation that has allowed almost all processors to sidestep the key environmental requirement of the 2007 law, the Renewable Fuel Standard (RFS), according to academics who have studied ethanol pollution and regulatory documents examined by Reuters. The rule requires individual ethanol processors to demonstrate that their fuels result in lower carbon emissions than gasoline."

"an EPA requirement that the plants use certain emissions-control processes the agency assumes will result in lower-than-gasoline emissions.

But the agency has exempted more than 95% of U.S. ethanol plants from the requirement through a grandfathering provision that excused plants built or under construction before the legislation passed. Today, these plants produce more than 80% of the nation’s ethanol" 

"the plants freed from regulation produced 40% more pollution per gallon of fuel capacity, on average, than the plants required to comply"

"Other industry observers say the RFS has utterly failed to meet its stated environmental goals. The ethanol mandate was “just a mistake,” said Timothy Searchinger, a senior researcher at Princeton University’s Center for Policy Research on Energy and the Environment. “We created a terrible model.”"

"Ethanol does have a key environmental advantage over gasoline: It burns cleaner in cars. The problem, biofuels researchers have found, is that those gains are offset by the pollution from planting corn and refining it into fuel.

Researchers from industry, government and academia seek to account for all these dynamics in estimating ethanol’s pollution throughout its full “life cycle” -- from farms to processing plants to automobile tailpipes.

The Reuters analysis examined one major part of that cycle - ethanol processing - based on the emissions data that most plants are required to report to the EPA. The data provides the only view of ethanol emissions tied to individual processors, allowing for comparisons among ethanol plants subject to the emissions-reduction regulation, those exempt from it, and their counterparts in oil refining.

Government and academic researchers have also sought to estimate the industry’s overall pollution, but they have come to sharply contrasting conclusions.

A growing consensus of academics has found that, considering all phases of the fuel’s life cycle, ethanol produces more carbon than gasoline - not less. A study published by the National Academy of Sciences in February, for example, estimated that ethanol produces 24% more carbon. read more"

"The [EPA] model greatly underestimates the industry’s pollution from corn agriculture, four academic researchers of ethanol told Reuters.

The EPA methodology relies in part on the work of a researcher from Purdue University in Indiana, whose model the agency selected at the ethanol industry’s suggestion"

"While the small number of ethanol plants subject to regulation produce 40% less pollution than the exempted plants, they still produce more pollution, on average, than oil refineries"

"Some scientists counter that corn planting would have dropped significantly without the government biofuels mandate. In the 25 years before the law’s passage, corn acreage declined nearly 7%, due in part to increasing yields per acre.

Moreover, corn acreage statistics do not account for millions of acres of corn for ethanol being planted on new lands -- the result of another EPA regulation that relaxed restrictions on the industry."

"farmers have planted about 5 million acres of conserved land with corn for ethanol, according to the National Academy of Sciences study. All that planting comes with “a carbon cost,”"

"Given the scientific disputes surrounding ethanol, industry and governmental claims of a major climate benefit are dubious, said Rich Plevin, an environmental consultant and former researcher at the University of California-Berkeley who has studied biofuels emissions.

“Did the policy achieve anything? I think it’s really hard to claim that it did for the environment,” he said."