The Bioethanol Binge

Fuel made from corn is expensive, inefficient—and undrinkable.

Aberdeen, South Dakota—“I’ve always wanted to know, can you drink what you guys make?,” I asked, sitting in Jim Lane’s office at the Advanced Bioenergy ethanol plant in Aberdeen, South Dakota. After all, ethanol plants ferment corn just like bourbon distilleries do. Lane smiled, pointed to a small jar of water-clear fluid on the table at which we were sitting, and said, “Open it up. Give it a smell.” I did. It felt like several layers of the cells lining my nostrils were being burned off. Lane smiled some more. The obvious answer was no. He explained that toxic stench in fuel ethanol emanates from fusel oil, a mixture of alcohols and fatty acids, which is used industrially to remove lacquer and enamel—that explains the eau de paint thinner—and is retained in fuel ethanol because it provides some extra energy. It also limits any temptation that a plant worker might have to take sip while on the job. In addition, to avoid paying beverage alcohol taxes the plant denatures its ethanol by adding two percent gasoline before shipping it.

Lane, a chemical engineer who is in charge of regulatory affairs at Advanced Bioenergy, generously agreed to give me a tour of the Aberdeen facility so that I could learn more about the process of producing fuel ethanol or bioethanol from corn. Last year, the country produced just over 11 billion gallons of bioethanol. In contrast, only about 1.2 billion gallons of ethanol were produced to drink in the form of wine, beer, and distilled spirits. The Energy Independence and Security Act of 2007 [PDF] mandates that the country will use 36 billion gallons of ethanol for fuel by 2022, which is equal to about a quarter of the 138 billion gallons of gasoline consumed domestically last year.

distillers grains

Upon arriving at the Advanced Bioenergy facility, a pleasant, familiar smell pervaded the environs of the Aberdeen plant. As I later learned, what I was smelling was distillers grains, a close cousin to the sweet cattle feed we used to get from the Southern States mill when I was a farm kid. Distillers grains is the term for what is left over after alcohol has been extracted. As Lane explained, roughly about one-third of the corn is starch (converted to sugar) that is fermented into ethanol; another third, mostly proteins, becomes feed; and the last third is carbon dioxide produced by fermentation and which is vented into the atmosphere. Lane hastened to explain that the facility’s carbon dioxide emissions were recycled carbon dioxide captured by corn plants and did not add to the greenhouse gas content of the atmosphere. The livestock feed is an additional revenue stream for the plant (currently $147 per ton for wet and $120 per ton for dry distillers grains), but ethanol production always provides the larger share of the revenues.

The Aberdeen plant began as a small facility in 1992 producing just 3.5 million gallons annually. In 2008, the plant was expanded at a cost of about $100 million, and now produces about 50 million gallons of bioethanol per year. This is achieved by grinding up 51,000 bushels of corn (2.8 million pounds) per day 355 days per year for a total of more than 18 million bushels annually. Each bushel yields about 3 gallons of ethanol. The plant employs 45 full-time employees.

ethanol vatLane gave me a thorough tour of the plant, showing me where the corn was ground up, softened using enzymes into a mash, and dosed with brewers yeast. We climbed up to peer into one of the fermentation tanks in which the yellowish mash appeared to be boiling furiously, but was actually bubbling away carbon dioxide. It generally takes about 50 hours for one of the giant tanks to finish fermentation. Lane showed me how alcohol was distilled and stored.

After the alcohol has been extracted, the distillers grains are processed through centrifuges which remove water containing some solubles. An evaporator reduces them to a syrup that can be added later to enhance the nutritional value of the distillers grains. The solids leave the centrifuge and are dried to produce, yes, dry distillers grains. Lane also showed me the labs in which samples from the fermentation tanks are constantly tested to make sure that they have not become infected with bacteria. If an infection occurs, the tanks are treated with penicillin.

Lane is an earnest believer in the benefits of ethanol and was eager to persuade me that ethanol was good for the country and the economy. Like many others whom I’ve met in the renewable fuels sector, he forcefully argued that ethanol helped free us from foreign oil, provided good jobs, boosted the economies of rural communities, and helped reduce our greenhouse gas emissions. When I asked Lane about the $6 billion in tax credits given to the ethanol industry by the federal government last year, he retorted that oil companies get subsidies too. In fact, The New York Times reported in July that the oil industry got $4 billion in tax breaks last year. Many of the tax breaks, however, are standard ones like deducting interest expenses that nearly every industry enjoys.

Currently, corn-based ethanol producers receive a tax credit of 45 cents per gallon. The tax credit offsets some of the production costs of bioethanol making it more competitive to gasoline. In July, boosters of corn ethanol were dismayed by a Congressional Budget Office (CBO) report [PDF] that found after adjusting for the difference in energy content between ethanol and gasoline plus adding in the amount of petroleum fuels burned to produce ethanol that actually the “the producers of ethanol made from corn receive 73 cents to provide an amount of biofuel with the energy equivalent to that in one gallon of gasoline.” The CBO further estimated that without the tax break bioethanol production would be about one-third lower than it is, which means that the “costs to taxpayers of using a biofuel to reduce gasoline consumption by one gallon are $1.78 for ethanol made from corn.” Historically, ethanol prices have generally been higher than gasoline prices [PDF], so ethanol has only been competitive with gasoline because of the tax subsidy.

And what about greenhouse gas reductions? The CBO cited life cycle calculations by the Argonne National Laboratory that found that a gallon of gasoline produces 12 kilograms of greenhouse gases whereas an energy equivalent amount of bioethanol produces 10 kilograms, about 20 percent less. So corn bioethanol would need to displace 424 gallons of gasoline in order to reduce greenhouse gas emissions by 1 metric ton. Multiplying this figure by the $1.78 cost to taxpayers of displacing one gallon of gasoline by bioethanol yields a cost of $754 to cut one metric ton of carbon dioxide. At the moment, carbon emission permits in the European market are going for just under $20 per metric ton.

In fact, whether or not producing corn ethanol actually reduces carbon emissions is still a hotly contested scientific question. Some researchers argue that land clearing to grow additional corn releases more carbon dioxide than bioethanol displaces by reducing the consumption of gasoline. Let's not forget the issue of how turning one-third of America’s corn crop into fuel impacts food prices, especially the prices of corn-fed beef and pork.

It’s past time for the ethanol industry (and all other energy supply industries) to stand on their own. Although this is probably a pipe dream, all energy subsidies should be ended and the market allowed to determine which fuels win. The ethanol tax credit expires at the end of this year. Congress should let it die.

Note: I am traveling back to the East Coast over the next couple of weeks from a summer in Montana spent working on a new book. Along the way I am visiting various energy production facilities. The goal of this circuitous trip is for me to get a better understanding of energy production and to geek out on technological marvels.

Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books. This column first appeared at

Ronald Bailey is Science Correspondent