Gevo starts isobutanol retrofit of Minnesota ethanol plant

By Holly Jessen | June 01, 2011

The retrofit of the Agri-Energy LLC ethanol plant started on May 31, with a groundbreaking ceremony attended by Gevo Inc. executives as well as U.S. Sen. Amy Klobuchar, Minnesota State Sen. Doug Magnus and Minnesota State Rep. Joe Schomacker. The ethanol plant is expected to be converted to full isobutanol production by June 2012. “Isobutanol made from renewable raw materials can be used to make a variety of everyday products such as rubber, plastics and fuel, and is a versatile solution to help displace our country’s dependency on petroleum and create a biobased economy,” said Patrick Gruber, CEO of Gevo. “Through this retrofit, Gevo is providing a high-value product that supports our nation’s agriculture industry.”

Gevo purchased the plant in September 2010. The plant has 27 employees, the majority of which were employees kept on after the transition, said Jack Huttner, executive vice president of corporate development and public affairs for Gevo. In addition to bring on the ethanol plant employees, Gevo has also been expanding the number of employees working at its headquarters in Englewood, Colo. In all the company employs about 100 people, including administration employees, sales, engineering and research and development employees.

An isobutanol separations unit will be built at the plant, next to the existing facility, Huttner told EPM. Another difference between corn ethanol production is the yeast used. Otherwise, the process is the same with corn as the feedstock and isobutanol as the final product. Although it’s not likely the plant will do a lot of switching back and forth, at the end of each batch it is possible to go back to ethanol production simply by changing the yeast used and turning off the valve to the separations unit, he said.

When the retrofit is completed the plant will produce about 18 MMgy isobutanol compared to the 22 MMgy of ethanol it produces today. However, because isobutanol has higher energy content than ethanol, the total Btu produced will be the same, the company says.

The company believes isobutanol is a “frontrunner in the race to end the United States’ dependency on petroleum.” It is a drop-in replacement for a variety of products and can be sold as either a solvent chemical or a fuel blendstock. It can also be converted into four-carbon building blocks called butenes which can be used to make 100 percent of all hydrocarbon fuels and 40 percent of all petrochemicals.