The per-gallon cost of producing cellulosic ethanol has been reduced from $4.13 to $2.35 over the first year of production at the Scotland, SD, cellulosic ethanol pilot plant utilizing corn cobs. That’s according to Poet, the ethanol company that has the goal of maintaining costs below $2/gallon by the time it starts up its Emmetsburg, IA, commercial cellulosic plant.

Reductions in energy usage, enzyme costs, raw material requirements and capital expenses contributed to the lower cost, says Jeff Broin, CEO of the ethanol company.

"Poet has been working on cellulosic ethanol for close to a decade, and there were some days that I wasn’t sure we’d be successful," Broin says. "While we still have some challenges ahead, I can say unequivocally that Project Liberty will be commercially viable by the time we start up the plant."

Project Liberty is the name of the planned 25-million-gallon-per-year commercials cellulosic ethanol plant.

Several areas of progress in the production process helped the company achieve its overall cost reduction:
* Chemical raw materials required in the process have been reduced, resulting in an operating cost savings of 20 cents per gallon.
* The energy used in the pretreatment process has been reduced by more than half.
* Alternative energy technology has been demonstrated to provide all of the energy for the cellulosic ethanol plant and at least 80% of the adjacent corn-based plant.
* Enzyme cost has been cut in half and is expected to decline by start-up of Project Liberty.
* Through continuous optimization of the process, entire unit operations have been eliminated, reducing overall capital cost by more than 40%.

"There are still several opportunities to make the process more efficient," says Mark Stowers, senior vice president of science and technology for Poet, "particularly in fermentation. Additionally, our enzyme partners have committed to significant additional cost reductions. But significant gains can also be made once we start up the commercial facility and Poet uses its 20+-year history in biorefining to drive cost reductions and efficiency improvements in the process."

The pilot-scale plant has produced about 20,000 gallons of cellulosic ethanol since it started producing in November, 2008. Click here for a documentary on the plant.