Gevo currently operates a biorefinery in Silsbee, Texas, in collaboration with South Hampton Resources Inc., to produce renewable jet fuel, octane, and ingredients for plastics like polyester.
The isobutanol brought to the Silsbee biorefinery is refined into sustainable aviation fuel (ATJ-SPK) and isooctane. To make drop-in alternative fuel from alcohols, the refinery must minimize differences in the alcohol-derived fuels and conventional fuels in physical and chemical properties. The three steps in the process include alcohol dehydration, oligomerization, and hydrogenation. These steps are already in use on a commercial scale.
Through dehydration, isobutanol is turned into isobutylene, a C4 building block, in a chemical process by stripping away the oxygen as water. Oligomerization turns the isobutylene into C8 and C12 olefins. The olefins have only one double bond and are readily hydrogenated to hydrocarbons. The resulting hydrocabons are distilled to ATJ and isooctane products. Isooctane is another marketable product, further diffusing the risk of investment in the process of producing ATJ.