As a part of its 10th Anniversary celebration, the Iowa Renewable Fuels Association on Tuesday released a list of the ethanol and biodiesel industry's Top 10 efficiency and technology innovations of the past decade. The Top 10 list was compiled through a survey of IRFA's membership.
"Much has been written about the growth of ethanol and biodiesel production … but the untold success story is the corresponding efficiency and technology innovations," stated IRFA Vice President and Absolute Energy CEO Rick Schwarck. "Clearly today's renewable fuels industry is not your father's gasohol plant."
U.S. Renewable Fuels Industry’s Top 10 Efficiency and Technology Innovations From the Past Decade:
1. Corn Production Gains
In 2001, the U.S. harvested 9.5 billion bushels of corn from 69 million acres, for a yield of 138 bushels per acre. Ten years later in 2011, 12.4 billion bushels of corn were harvested from 84 million acres, resulting in a 147 bushels per acre yield.
2. Ethanol Yield Increases
Since 2001, the average ethanol yield in the U.S. has increased 3-5% to roughly 2.8 gallons per bushel. Without this improvement it would have taken an additional 250 million bushels of corn to generate 2011's ethanol production. The improved yield has been fueled by ethanol producers' investments in enhanced enzymes such as alpha amylase, which improves the breakdown of starch in corn to maximize the conversion to ethanol. Similarly, ethanol production has also seen huge improvements in yeast varieties. Today's ethanol plants utilize yeast that have been engineered specifically for the ethanol industry to withstand high concentrations of alcohol, high temperatures, and infections. There are even strains of yeast today that secrete their own enzymes to enhance ethanol production.
3. Water Utilization Improvements
Over the past decade, water use in dry mill ethanol plants has dropped from 4.7 to 2.72 gallons of water per gallon of ethanol produced. This change has been made possible by improved anti-scaling agents, which allow ethanol plants to recycle an increased amount of cooling water as process water prior to discharging.
4. Energy Efficiency Advancements
Compared to 2001, ethanol production today requires 28% less thermal energy (from natural gas or coal) per gallon and 32% less electricity per gallon. One breakthrough was the advent of low cook fermentation. Instead of heating slurry tanks to 230 degrees a new enzyme allows starch to be converted to sugars at only 175 degrees, dramatically reducing the need for steam heat. Additional factors contributing to improved energy efficiency for ethanol production include the increased use of heat exchangers, which allow plants to reuse heat from the production process, and advanced process controls which enable more efficient operations in boilers and dryers.