Species transport and reaction characteristics between gas and solid phases for ex-situ catalytic pyrolysis of biomass

Simultaneous reaction and separation in ex-situ catalytic pyrolysis of biomass was proposed to increase product yield and reduce carbon residue in short residence time. A novel cyclone reactor was designed to implement this process. The low cyclonic flow in the upper part of the reactor can efficiently increase gas (biomass pyrolysis vapors)-solid (catalysts) two-phase contact efficiency, and further enhance the catalytic effect. The strong cyclonic flow generated under the action of guide vanes in the lower part can ensure good separation effect between catalysts and gaseous products. The results indicate that the mean residence time of catalysts is 1.2e1.5 s. The effects on backflow and reaction characteristics were investigated for various operating conditions. The yield ratio of the desired product bio-oil is 54.2% under the optimal parameters obtained in this article. This work provides theoretical basis for improvement of biomass high-value utilization technology. (c) 2021 Elsevier Ltd. All rights reserved.