Liquid Fuels by Low-severity Hydrotreating of Biocrude

Biocrude (fast pyrolysis oil from wood) was hydrotreated to minimize the negative aspects of this fuel. The instability of the oil was reduced by reaction of the most unstable functional groups. Concurrently, the oxygenated component of the oil was also reduced, resulting in an improved energy density. Changes in the physical handling properties were also modified. All of this change was accomplished at less severe processing conditions (lower temperature, shorter residence time) than that required for the earlier processing for gasoline production. Improved conversion was achieved by the use of a downflow reactor system. The experiments reported include those performed with clean (filtered hot vapor) biocrude just recently available from processing systems in the U.S.