Simulation of municipal solid waste gasification in two different types of fixed bed reactors

Simulation of municipal solid waste (MSW) gasification with air in two different types of fixed bed reactors has been carried out by using Aspen plus. One type of the fixed bed reactors is an updraft fixed bed reactor which can be divided into four sections (drying, pyrolysis, gasification, and combustion), and the other type is different in the last two sections that the flue gas from the combustion section is not introduced into the gasification section. The effect of flue gas from the combustion section on the composition and lower heating value (LHV) of syngas, heat conversion efficiency, and carbon conversion at different gasification temperatures and air equivalence ratios are investigated. The results indicate that the introduction of flue gas from combustion section into the gasification section improves the heat conversion efficiency and the LHV of syngas. Carbon conversion increases with the increase of gasification temperature and air equivalence ratio in both reactors. The concentration of each component in syngas is different in the two types of reactors at lower air equivalence ratio, but no difference can be found at higher air equivalence ratio. (C) 2011 Elsevier Ltd. All rights reserved.