August 11, 2008

Biofuels

Cellulose Direct

Integrated, nonfermentation process simplifies conversion of cellulose into an alternative furan-based fuel

Rachel Petkewich

A streamlined chemical method that permits easier, direct conversion of purified cellulose into a biofuel has been devised by researchers at the University of California, Davis (Angew. Chem. Int. Ed., DOI: 10.1002/anie200801594). The process transforms cellulose into 5-(chloromethyl)furfural (CMF) and then into 5-(ethoxymethyl)furfural (EMF), which is a promising alternative fuel.

Ethanol, currently the most widely produced biofuel, is made via a fermentation process that is relatively slow and expensive and requires simple sugars from food crops as feedstock. To use nonfood cellulose as a fuel source, a conversion method that can efficiently and cost-effectively break down cellulose on a large scale is necessary.

Other researchers have catalytically converted biomass-derived sugars into furan-based compounds that are potentially useful as biofuels. But UC Davis’ Mark Mascal and Edward B. Nikitin advanced this process by eliminating a separate step to break down cellulose.

The researchers use a solution of HCl and LiCl to digest pure cellulose. They continuously extract with recycled dichloroethane to obtain CMF along with minor furan products in 85% yield. This intermediate mixture is combined with ethanol to produce EMF.

Mascal and Nikitin say the process works equally well when starting with sucrose, glucose, or even tough lignocellulosic biomass such as cotton, straw, and wood.

Chemical & Engineering News

ISSN 0009-2347

Copyright © 2009 American Chemical Society