Production of low oxygen bio-oil via catalytic pyrolysis of forest residues in a kilogram-scale rotary kiln reactor

Co-processing of pyrolysis bio-oils with fossil feedstock in existing refineries has been identified as a way to introduce renewable carbon in transportation fuels. Significant deoxygenation of bio-oil, which can be achieved by catalytic pyrolysis, is a prerequisite to increase the amount that could be supplied. In this study, following the optimisation of the conversion of eucalyptus residues using calcium oxide catalyst at bench scale, pyrolysis tests have been conducted at kilogram-scale on a rotary kiln reactor to investigate the suitability of produced bio-oils for co-processing. A fractional condensation technique was also employed to reduce the bio-oil water content in a single step. The results evidenced enhanced deoxygenation at kg-scale as a consequence of greater interactions between catalysts and volatiles in the rotary kiln reactor. The combination of enhanced deoxygenation and fractional condensation resulted in the production of an organic rich fraction with an oxygen content of 12.6 wt% and a Higher Heating Value of 35.5 MJ/kg (dry basis). This fraction could be considered for co-processing in a Fluid Catalytic Cracking unit to produce transportation fuels. [Display omitted] •Low oxygen bio-oil via catalytic pyrolysis for renewable transport fuels production.•34% increase in the energy content of bio-oil when scaling up.•Extensive catalyst/biomass contact in semi-continuous reactor.•Bio-oil with oxygen content of 12.6 wt% and energy content of 35.5 MJ/kg.•Fractional condensation to obtain a bio-oil with a water content of 19.7 wt%.