Clean Technology 2009
P. Steele, S. Gajjela, F. Yu, G. Gresham
Mississippi State University, US
biomass, pyrolysis, hydrodeoxygenation, hydrocarbon
Bio-oils produced from pyrolysis of biomass are chemically complex compounds. As fuels they have a number of negative properties such as high acidity, water content, variable viscosity and heating values about half that of diesel fuel. These negative properties are related to the oxygenated compounds contained in bio-oils that result in a 45% oxygen content. For production of a viable fuel the raw bio-oils must be upgraded. The bio-oil hydrotreating process has been approached by applying hydrogenation catalysts under heat and pressure. Researchers have reported application of a successful two-stage catalytic hydrodeoxygenation (HDO) process. We have recently developed a single-stage HDO catalysis. The upgraded bio-oil contains hydrocarbons very similar to petroleum diesel. Yields of the upgraded bio-oils are more than 70% by energy capture. Future research on the upgraded product will focus on distillation and introduction into petroleum refineries and investigating the potential for direct blending with current petroleum fuels.