Biomass gasification in a downdraft fixed-bed gasifier: Optimization of operating conditions

In the present study, a CFD model was developed for the biomass gasification process in a downdraft fixed-bed gasifier. Sugarcane bagasse was used as feedstock in gasification experiments and simulation studies. Several operating parameters, including the velocity and preheating temperature of the inlet air/steam mixture, steam to air ratio (S/A), and biomass moisture content (MC), were investigated to achieve the maximum syngas yield (CO2, H-2, CH4, and CO) and conversion efficiency. Results proposed that the syngas yield and conversion efficiency were maximized at S/A of 0.67 and inlet velocity of 20 m/s. In addition, increasing the preheating temperature of air/steam and decreasing the MC of bagasse had positive impacts on the gasification process. The maximum conversion efficiency was 69.14% at the optimum operating conditions. This study offers an advanced tool for the simulation of gasification process that can be used in primary-stage engineering designs. (C) 2020 Elsevier Ltd. All rights reserved.