Ethanol Burns Clean, But Creates More Emissions Than Gasoline

Ethanol has many uses, including as a fuel for internal combustion engines. According to North Dakota State University, ethanol was first used to power an engine in 1826. Fifty years latter, Nicolaus Otto, the inventor of the modern 4-cycle engine, used ethanol to power one of his first internal combustion prototypes. It also fueled the Ford Model T in 1908. The first ethanol blended with gasoline for use as an octane booster occurred in the 1920s and 1930s, and was in high demand during World War II because of fuel shortages.

During the OPEC oil embargoes in the 1970, it again became a popular substitute for expensive gasoline. Then in 2007, Congress created a Renewable Fuels Standard that mandated corn-based ethanol be blended with gasoline as a way of reducing tailpipe emissions from automobiles.

Ethanol Burns Clean

When used as a motor fuel, ethanol burns cleaner than gasoline. There is no dispute about that. But there is a dispute about the carbon emissions created in the manufacturing process that makes ethanol from corn. According to recent research by Reuters, ethanol plants in the US produce more than double the harmful emissions, per gallon of fuel production capacity, than the nation’s oil refineries.

That research found that ethanol plants created 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 only 533 metric tons of carbon.

The Renewable Fuels Standard

The law requires the ethanol industry to demonstrate that its fuel delivers a 20% reduction in carbon emissions compared with gasoline. The percentage is based on the EPA’s model for estimating emissions from all phases of the fuel’s life cycle, including agricultural and fuel consumption. And that’s where things start to go sideways.

The EPA has exempted more than 95% of all US ethanol plants from the requirement because they were built or under construction before the legislation passed. Today, these plants produce more than 80% of the nation’s ethanol. According to the EPA, about a third of the ethanol plants do meet the law’s environmental standard even though they are not required to do so. But as a group, the plants freed from regulation produced 40% more pollution per gallon of fuel capacity, on average, than the plants required to comply, the Reuters analysis found.

The grandfathered facilities produced 4.8 million tons more carbon emissions than they would have if they had been required to comply with the standard, according to a Reuters calculation based on the average emissions from regulated and unregulated plants. That’s equivalent to the emissions of more than a million cars.

The Congressional mandates for expanding biofuels expire later this year, placing the future of the RFS at the discretion of the EPA. The agency has yet to publicly detail any proposed revisions. The White House declined to comment on the Reuters findings. For its part, the EPA said it has followed the intent of Congress in implementing the biofuels law, including the regulatory exemptions. The agency acknowledged the higher production emissions of ethanol, compared to gasoline, but asserted that ethanol is cleaner overall.

Corn, Ethanol, & Politics

The EPA touts the benefits of ethanol on rural economies and national security. “Renewable fuels help diversify our nation’s energy supply, improving energy independence and security,” it told Reuters, and added that biofuels provide “good paying jobs and income to farming communities.”

For those of you who live on the coast, you may not know much about farming in America’s heartland, but woe betide any politician who dares campaign in a flyover state who does not get photographed eating an ear of corn, a corn dog, or a bowl of corn chowder. Corn is a religion in farming communities and Joe Biden knows it. There will be no action by the EPA that discombobulates rural voters before the next congressional elections in November.

The desire to appeal to those voters has played a central role in the RFS regulations crafted by the EPA. The agency bases its claim that ethanol benefits the climate on calculations made nearly 15 years ago using a handful of scientific models. The models include one that was recommended to the agency by the Renewable Fuels Association, agency documents show.

When Congress passed the RFS, it required the EPA to model ethanol’s emissions profile to verify it could meet the emissions reduction standard. The EPA’s first pass at the calculation in 2009, however, found that ethanol would result in a 5% increase in greenhouse gas emissions over gasoline, which would have barred the fuel from the blending mandates.

Industry groups including the RFA bristled at the calculation and urged the agency to change the formula. The industry recommendations included adopting a model maintained by the Global Trade Analysis Project (GTAP) at Purdue University to estimate the pollution generated by planting corn for ethanol, EPA records of the debate show.

The EPA redid its modeling and used GTAP to test its results, according to a 2010 Congressional Research Service report. It concluded ethanol’s emissions were 21% lower than gasoline, putting the biofuel just barely over the 20% threshold for RFS compliance. The agency told Reuters that it did not make the modeling change solely at the industry’s request, but rather included input from “government, academia, industry, and not-for-profit institutions.”

The Purdue model is led by Dr. Farzad Taheripour, a researcher and professor of agricultural economics. He said the model was modified over time to reflect real world observations of how biofuels production has affected land use. For instance, early scholarship on ethanol regulation suggested the RFS would lead to deforestation, which did not occur.

Taheripour has received research funding from several biofuels industry trade groups since 2012, including the Renewable Fuels Association, National Corn Growers Association, Indiana Corn Soybean Alliance, and National Biodiesel Board, according to a Reuters review of his research funding disclosures.

Reuters was not able to determine the total amount of industry grants Taheripour has collected or the amount he may have received from other sources. Taheripour said his funding sources do not affect his research methods or outcomes.

Follow The Science, But Which Science?

The Purdue model approach to estimating agricultural emissions has been disputed by academics. A growing consensus among them 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, Reuters reports.

That study was funded in part by the National Wildlife Federation and the Department of Energy. Isn’t it interesting how two government agencies can come to such widely divergent views? The ethanol mandate was “just a mistake,” Timothy Searchinger, a senior researcher at Princeton’s Center for Policy Research on Energy and the Environment, told Reuters. “We created a terrible model.”

Geoff Cooper, president of the Renewable Fuels Association, disagrees and said that ethanol is cleaner than gasoline. “Ethanol offers a significant and immediate carbon savings,” he told Reuters. Other industry observers said the RFS has utterly failed to meet its stated environmental goals and that the EPA has used a controversial methodology to estimate the ethanol industry’s life cycle emissions that has effectively ensured the industry’s continuing regulatory compliance. That model greatly underestimates the industry’s pollution from corn agriculture, four academic researchers of ethanol told Reuters.

Researchers cannot even agree on the amount of carbon sequestered by agricultural land. The bulk of ethanol emissions are produced when new land is tilled for corn production, releasing carbon that is stored in soil and roots. Two biofuel experts told Reuters that the team working on the Purdue model has steadily reduced its estimate of how much carbon is released from tilled land over the years, making ethanol appear more climate friendly.

For instance, the model has been adjusted over the past decade to overstate increases in corn yields, resulting in an underestimate of emissions from planting, according to a study published in 2020 by the Journal of Cleaner Production, an academic publication focused on sustainability. The changes raise concerns about the model’s credibility and result in a “really lowball estimate” for agricultural emissions from ethanol, said Stephanie Searle, director of the fuels program at the International Council on Clean Transportation, a nonprofit research organization.

During its initial RFS rulemaking, the EPA allowed new corn planting for ethanol on land enrolled in the US Department of Agriculture’s Conservation Reserve Program, which pays farmers a monthly rent to keep fragile land idle.

Since then, 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,” said Tyler Lark, a scientist at the University of Wisconsin-Madison’s Center for Sustainability and the Global Environment.

Taheripour dismissed the idea that the ethanol industry’s new corn plantings produced much pollution. “CRP land is nothing but unused cropland,” he said. “Unused land does not have the capability to capture lots of carbon.”

The USDA has for years claimed otherwise. It has said unused farmland in its CRP program soaked up massive amounts of carbon. Touting the program as a major solution to climate change, the department estimated between 2006 and 2017 that such lands contained about 1.4 metric tons of carbon per acre, on average. Asked about the climate benefits of CRP land, however, the USDA told Reuters it had recently lowered its estimate of carbon in such lands by nearly half, to 0.8 metric tons per acre, after reviewing updated data.

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. The best we can say is, no one really knows.”

The Takeaway

Great. Now we have the EPA, the DOE, and USDA all disagreeing with each other. Is there anything we can learn from all this controversy? Yes, there is. Biofuels are a charade, a way to keep the internal combustion engine alive and well for a few more decades despite its horrific impact on the environment.

The issue is not that one fuel is cleaner than another. The issue is that burning stuff — any stuff — to power our societies is a negative sum game that endangers every person alive today and all those who will follow in their footsteps.

Guardian columnist George Monbiot wrote recently, “From inception, the incentives and rules promoting biofuels on both sides of the Atlantic had little to do with saving the planet and everything to do with political expediency.”

At a time when catastrophic floods and droughts are threatening millions with starvation, how wise is it to use productive land to grow corn for ethanol to save a few carbon emissions when electric cars produce no tailpipe emissions at all?

Clearly Big Ag has played a major role in crafting the renewable energy standard and pushing for more corn-based ethanol. The biggest producer of ethanol for fuel in the US is agriculture giant Archer Daniels Midland. Ethanol from corn is more about buying votes in the farm belt and less about being good stewards of the Earth. The Biden administration should move on from the RFS, but probably lacks the political will to do so.


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