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Dry mill ethanol shows improvement in efficiencies

June 3, 2010, Washington, D.C. - Newly published research in the scientific journal Biotechnology Letters shows tremendous gains in production efficiencies by America’s dry mill ethanol biorefineries.

November 30, 1999  By Renewable Fuels Association

Dry mill facilities represent nearly 90 percent of America’s total ethanol production, estimated to be in excess of 12 billion gallons in 2010.

The research, conducted by Dr. Steffen Mueller at the University of Illinois at Chicago, compared the dry mill production efficiencies in 2008 to those in 2001. The research included responses from approximately 66% of the nation’s installed dry mill ethanol production capacity. Key findings of the research include:

•    Thermal energy use was less than 26,000 BTU/gallon on average, a reduction of 28 percent compared to 2001 data
•    Electricity use was reduced by 32 percent compared to 2001 data
•    Ethanol yields per bushel processed improved 5.3 percent since 2001
•    Total water use was 2.72 gallons per gallon of ethanol produced, down significantly from previous estimates


“America’s ethanol industry is in a constant state of evolution,” said Renewable Fuels Association President and CEO Bob Dinneen. “Existing grain ethanol producers are continuously investing in the latest technologies, retrofitting older facilities and incorporating these technologies in new construction. As a result, the industry is perpetually improving its efficiency and enhancing the environmental benefits it already offers.”

Dinneen continued, “Such demonstrated innovation flies in the face of environmental activists claims that American ethanol producers are simply operating under the status quo. Ethanol production is constantly improving its efficiency, while oil production is going the opposite direction. Drilling in deep waters and mining tar sands require a great deal of energy and cause untold environmental damage.”

By capturing such a large cross-section of the industry, this survey and research are the most comprehensive to date on U.S. ethanol industry efficiencies. This data is important to ongoing efforts to determine the carbon footprint of ethanol as it relates to federal carbon legislation and state efforts on low carbon fuels standards. The report is also an important landmark in larger discussions about the overall environmental and economic sustainability of ethanol.

In particular, this research dovetails with a recent report from Purdue University on corn ethanol’s possible land use impacts. The new Purdue research shows potential land use change impacts being half of what the U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) concluded. These two studies provide the kind of data and analysis needed to make more informed calculations and judgments. They further prove that when the most current data and assumptions are used, there is no doubt that modern ethanol provides significant greenhouse benefits compared to gasoline.

“Taken together, these landmark studies of American ethanol production should re-inform and redirect the current debate about ethanol’s carbon footprint,” said Dinneen. “As more scientists look into the issue, they are finding that ethanol is an increasingly cleaner and greener alternative to oil. I encourage EPA, CARB, and any other entity seeking to evaluate ethanol’s environmental profile to review these studies thoroughly.”

Dr. Mueller’s work also uncovered some additional data points useful to informed debate about ethanol production. Among these points are:

•    Approximately 30 percent of all respondents produce corn oil in addition to livestock feed, known colloquially as distillers grains (in both dry and wet form).
•    The average corn draw circle for respondents was 47.1 miles, demonstrating that a large portion of all corn used in ethanol production is sourced locally.
•    Ethanol distribution from the facilities responding breaks down as follows: 25 percent by truck, 3 by ship or barge, and 72 percent by rail.

The Biotechnology Letters publication by Dr. Mueller can be purchased here. The full report on which the Biotechnology Letters piece was based is availablehere.


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