C O M P L E T E D   P R O J E C T S

Increasing the Value of Corn by Fermenting Corn Fiber to Butanol
Submitted by Nasib Qureshi and Hans P. Blaschek, University of Illinois

Qureshi: Nasib.Qureshi@ARS.USDA.gov
Purpose

During the late seventies and early eighties there was considerable international interest among various governmental, business, and scientific groups to pursue the production of alcohol fuels from easily and widely produced renewable resources.

A mixed degree of success was achieved in various countries with the bioconversion of alcohol fuels. Oil shortages emphasized the need for, and potential of, alcohol fuels such as ethanol. But depressed crude oil market prices led to diminished interest in higher-priced alcohol fuels. Production of alcohol fuels is not inexpensive.

Butanol (the focus of this project) is a chemical that has excellent fuel characteristics. It has a higher calorific value than ethanol and a low freezing point. There has been recent interest in the research on the production of butanol using the physiologically diverse genus Clostridium.

Economic studies suggest that fermentation of by-products such as corn fiber will significantly improve the economics of butanol production from corn. It is suggested that studies be carried out to hydrolyze and ferment corn fiber to maximize production of butanol (acetone butanol ethanol [ABE]) from corn using Clostridium beijerinckii BA101, and that butanol be recovered in situ to further economize the process.

Objectives

  • Objective 1: Hydrolysis of corn fiber by dilute acid treatment.
  • Objective 2: Optimization of concentration of hydrolyzed corn fiber to produce butanol using C. beijerinckii BA101 and P2 medium.
  • Objective 3: Optimization of light corn steep water (CSW) concentration for maximal production of butanol in batch reactor 1-2 L bioreactor.
  • Objective 4: In situ recovery of butanol from optimized corn fiber (hydrolyzed) fermentation.
Impact

These studies in combination with efficient butanol recovery would significantly reduce butanol price. It is anticipated that with these developments, butanol price would range from $0.18/lb to $0.20/lb. Bioconversion of corn to butanol has reached a stage (nearing commercialization) that U.S. farmers would reap benefits.

It is expected that butanol commercialization would create a market for 200 million bushels of corn per year.