CATALYTIC UPGRADING OF BIOMASS-DERIVED OILS TO TRANSPORTATION FUELS AND CHEMICALS

This paper provides a review of the catalytic upgrading of biomass-derived oils such as wood pyrolytic oils, plant/vegetable oils and tall oil to transportation fuels and useful chemicals. Both zeolite and hydrotreating type catalysts have been found suitable for upgrading which was usually done in fixed bed reactors. The hydrotreatment of pyrolytic oils at 250-450-degrees-C and 15-20 MPa H-2 pressures has been reported to yield up to 55 wt. % of liquid product containing 40-50 wt. % of gasoline range hydrocarbons. In the case of HZSM-5, the upgrading has been carried out at atmospheric pressure and 350-500-degrees-C and over 85 wt. % conversions of plant oils and tall oil have been achieved under optimum conditions. Liquid product yields from these oils were up to 70 wt. % of feed which contained 40-50 wt. % aromatic hydrocarbons. With the high pressure pyrolytic oil, pitch conversions of over 75 wt. % have been observed with HZSM-5 using co-feeds such as tetralin. However, there is only scant information available on the kinetic and mechanistic aspects of upgrading of these oils.