While political battles over the Renewable Fuel Stan­dard (RFS) continue to grab headlines, Iowa’s ethanol plants are quietly pushing ahead and becoming more and more efficient.

The 43 corn-based and cellulosic ethanol plants in the state are increasing their yields of biofuels from corn and other feedstocks they purchase from farmers. They are using less water and energy to make fuel. And they have improved processes for extracting oils and making livestock feed from dried distillers grain that remains after the distillation process.

Consistent progress

The incremental gains by Iowa ethanol plants have been consistent and have helped farmers and all of Iowa by creating additional jobs in rural areas and contributing to the local tax base, said Monte Shaw, executive director of the Iowa Renewable Fuels Association.

"It’s not like a grand slam that you hear a lot about. But it’s a lot of singles that add up and make a major difference," Shaw said about the efficiency gains. "It’s really like putting up three new 100 million gallon plants a year, without adding any steel."

Ethanol plants, especially those built about a decade ago, were very efficient. But leadership at the plants have continually found ways to be more efficient.

Added to that, Shaw said, farmers are continually become more efficient at growing corn and corn stover that is used by ethanol plants to make fuel.

Those efficiency gains were documented earlier this year in a U.S. Department of Agriculture (USDA) report on efficiency gains in the country’s ethanol industry. The ethanol industry, the USDA report said, "has made the transition from an energy sink, to a moderate net energy gain in the 1990s, to a substantial net energy gain in the present."

The report, authored by Iowa State University economist Paul Gallagher and others, showed that the entire U.S. ethanol industry had steadily improved its efficiency since the mid-1990s. Now, an average ethanol plant produces more than twice the energy than it consumes.

But many Iowa plants, especially those in the western half of the state, are well above average. They have doubled that efficiency by producing four times the energy they consumed, the report found. These plants were at the top of the efficiency chart because they are close to ample corn supplies and livestock feeding operations, so it is efficient to market distillers grains for feed. The plants also have access to transportation infrastructure and end markets, especially along the I-35 and I-29 corridors.

One contributor to ethanol efficiency has been the use of biotech corn called Enogen that was developed by Syngenta. Ethanol plants pay farmers a premium to raise the corn, which contains a transgene from a bacteria that produces alpha amylase, an enzyme that breaks down corn starch into sugar. That eliminates the need to add enzymes, as ethanol plants have traditional done.

The Enogen technology was pioneered by Quad County Corn Processors in Galva and is now used in nearly 20 ethanol plants. Quad County has also adopted Cellerate, a collaboration between Syngenta and Cellulosic Ethanol Technologies process, which allows it to convert corn kernel fiber to ethanol and further increase efficiency.

Corn oil extraction

Another contributor to the efficiency gains has been the extraction of corn distillers oil by ethanol plants, according to Shaw and others. The oil, which takes relatively little energy to extract, can be sold as a feedstock for biodiesel.

In addition, Shaw said, suppliers to the ethanol industry, such as yeast makers, have contributed to efficiency gains by developing specific products for ethanol makers.

There is still plenty of room for the ethanol industry to increase efficiency and improve its energy balance, according to the USDA report. There is potential in using alternative fuel sources, such as biomass, and improved ways of marketing distillers grains to the livestock industry, the report said.