Numerical Simulation of a Serial Composite Gasification Process for Biomass and Coal
This study investigates a serial composite gasification process for biomass and coal using computational particle fluid dynamics (CPFD) modeling. The model comprehensively accounts for bed hydrodynamics, particle dynamics, heat and mass transfer, and homogeneous and heterogeneous chemical reactions. The effects of various operating variables on gas composition, gas yield, and gasification efficiency are examined. Results indicate that increasing gasification temperature is beneficial, and the influence of turbulence within the reactor must be considered. The gasification reaction mechanisms differ under varying steam-to-biomass mass ratios (SBR): at low SBR, gas-solid reactions in the dense phase are promoted, whereas at high SBR, homogeneous reactions at the dilute phase outlet are enhanced. A higher biomass-to-coal mass ratio (BCR) is recommended. The gasification performance of different biomass feedstocks shows minimal variation, demonstrating the substitutability of biomass raw materials in this process. The study provides a theoretical basis for optimizing gasification technology and improving efficiency.