Catalytic Hydroprocessing of Fast Pyrolysis Bio-oil from Pine Sawdust

Catalytic hydroprocessing has been applied to the fast pyrolysis liquid product (bio-oil) from softwood biomass in a bench-scale continuous-flow fixed-bed reactor system. The intent of the research was to develop process technology to convert the bio-oil into a petroleum refinery feedstock to supplement fossil energy resources and to displace imported feedstock. This paper is focused on the process experimentation and product analysis. A range of operating parameters, including temperature from 170 or 250 to 400 degrees C in the two-stage reactor and flow rate of 0.19 liquid hourly space velocity, was tested with bio-oil derived from pine wood. Times on stream of up to 90 h were evaluated, and losses of catalyst activity were assessed. Product yields of 0.35-0.45 g of oil product/g of dry bio-oil feed with hydrogen consumptions from 342 to 669 L/L of bio-oil feed were measured. Analyses determined that product oils with densities of 0.82-0.92 g/mL had oxygen contents of 0.2-2.7 wt % and total acid number (TAN) of <0.01-2.7 mg of KOH/g. In summation, the paper provides an initial understanding of the efficacy of hydroprocessing as applied to the Finnish pine bio-oil.