HYDROPROCESSING OF DIRECTLY LIQUEFIED BIOMASS WITH LARGE-PORE CATALYSTS

Different extracted fractions of directly liquefied biomass were hydroprocessed in order to determine the effects on the products from pore volume distribution of the catalysts used. Desalted, directly liquefied biomass from the PERC process was consecutively extracted with isooctane and xylene. The hydroprocessing was performed in a downflow reactor with sulfided catalysts. Catalysts with larger pore diameters maintained the pore structure better in the experiments, although the amount of coke on the catalyst after the run was equal or higher with the large pore catalysts. The oxygen content is reduced from 8-15% in the feed soils down to 2-6% in the products. The sulfided CoMo catalyst (Ketjen 742) with narrow pores gave the best deoxygenation of the catalysts tested at 350 °C. The oil with the lowest oxygen content (extracted with isooctane) showed the lowest deoxygenation and change in molecular weight distribution. The amount of material with boiling points over that of n-C44 was reduced from 45% down to 4-5% with the Ketjen 742 catalyst at 420 °C. © 1990, American Chemical Society. All rights reserved.