Autocatalytic co-upgrading of biochar and pyrolysis gas to syngas

Abstract

A new strategy is exploited toward dramatically increased carbon utilization efficiency of biomass fast pyrolysis by implementing co-upgrading of by-products (biochar and pyrolysis gas) of fast pyrolysis. Simultaneous autocatalytic conversion of biochar and pyrolysis gas is demonstrated using a fixed-bed reactor and an isothermal thermogravimetric analyzer. The reaction of corncob char with simulated pyrolysis gas reveals the feasibility of producing valuable CO and H2 under suitable reaction temperature (>800 °C). The reactivity of biochar and simulated pyrolysis gas increases with increasing potassium content. The raw corncob biochar exhibits high reactivity owing to its high indigenous potassium content. Furthermore, kinetic analysis demonstrates that the modified random pore model (MRPM) satisfactorily describes the reaction behavior of corncob biochar and CO2. The activation energy calculation verifies that the co-upgrading of raw corncob biochar and pyrolysis gas for the production of syngas is feasible at suitable temperature without further treatment.