The Higher Alcohols Biorefinery II:

Edwin S. Olson,* Ramesh K. Sharma and Ted R. Aulich

Grand Forks, ND 58202

Phone: (701)777-5000

Fax: (701)777-5181

E-mail: eolson@undeerc.org

A biorefinery for production of higher alcohols via Guerbet condensation reactions of ethanol and methanol over carbon catalysts was demonstrated in the previous (25th) Symposium on Biotechnology for Fuels and Chemicals. For formation of oxygenated high-cetane diesel additives, the concept is to integrate the Guerbet self-condensation of fermentation ethanol with other coupling reactions that produce linear molecules in the molecular weight range of 130 to 180 amu. The self-condensation of ethanol results in the formation of 1-butanol accompanied by smaller amounts of 1-hexanol and minor amounts of many aliphatic and aromatic compounds. Subsequent conversion of these to ethers and other derivatives produces compounds in the desired molecular weight range for diesel additives as well as useful solvents. These oxygenated species have low volatility compared with ethanol, dissolve readily in hydrocarbon fuels, and are immiscible with water. Cetane numbers and viscosities are exceptional.