Separated Biochar and Pyrolysis Gas of Biomass via Chemical Looping for Methanol and Ammonia Production

Abstract

In this research, a novel integrated methanol and ammonia production via chemical looping is developed utilizing the separated biochar and pyrolysis gas from fast pyrolysis unit. The proposed system uses biomass as a feedstock due to its huge global potential. Process modelling and evaluation are conducted using a steady-state process simulator. The fixed bed pyrolysis is adopted to separate pyrolysis gas and biochar. The pyrolysis gas is processed in the steam bio-oil reformer for hydrogen production, while the biochar is fed to the chemical looping unit as a reducing agent. Other processes, including hydrogen separation and thermal energy circulation processes for hydrogen production, are proposed and simulated based on the previous studies. The by-produced CO2 from the reducer of the chemical looping unit is processed with H2 produced from a steam bio-oil reformer to produce methanol. In addition, to increase the overall efficiency, ammonia is synthesized using hydrogen and nitrogen produced from the oxidizer and combustor of the chemical looping unit. This novel system is expected to be able to produce both methanol and ammonia from low-rank feedstock with high energy efficiency. The highest methanol and ammonia production efficiency achieved through the simulation was 10.3 % and 29.2 %.