Prediction of Rice Husk Gasification on Fluidized Bed Gasifier Based on Aspen Plus

Abstract

A biomass gasification model was developed using Aspen Plus based on the Gibbs free energy minimization method. This model aims to predict and analyze the biomass gasification process using the blocks of the RGibbs reactor and the RYield reactor. The model was modified by the incomplete equilibrium of the RGibbs reactor to match the real processes that take place in a rice husk gasifier. The model was verified and validated, and the effects of gasification temperature, gasification pressure, and equivalence ratio (ER) on the gas component composition, gas yield, and gasification efficiency were studied on the basis of the Aspen Plus simulation. An increasing gasification temperature was shown to be conducive to the concentrations of H2 and CO, and gas yield and gasification efficiency reached peaks of 2.09 m3/kg and 83.56%, respectively, at 700 °C. Pressurized conditions were conducive to the formation of CH4 and rapidly increased the calorific value of syngas as the gasification pressure increased from 0.1 to 5 MPa. In addition, the optimal ER for gasification is approximately 0.3, when the concentrations of H2 and CO and the gasification efficiency reach peaks of 23.65%, 24.93% and 85.92%, respectively.