Performance assessment of municipal solid waste operated modified downdraft gasifier for variations of air input and preheated air temperature

Background: Many municipal solid wastes (MSWs) produced worldwide can be used as an alternative to fossil energy. Synthetic gas produced from gasification of MSW can be used as fuel gas in various applications. Methods: It deals with the performance assessment of a modified downdraft gasifier using MSW RDF pellets as feedstock under different equivalence ratios (ERs), air ratios (ARs), and preheated air temperatures (PATs). The effect of distinct values of ER, AR, and PAT on the cold gas efficiency (CGE), carbon conversion efficiency (CCE), and the concentrations of the syngas components were determined. Results: The optimum values of ER and AR for unheated air were ۰.۴ and ۰.۶۶, respectively, which have been tested for the effect of PAT (from ۱۰۰ to ۲۱۰°C). It was found that air preheating improved the performance of the gasification process, in which the percentage of the flammable gases increased CO (from ۱۷.۳% to ۲۶.۲%), H۲ (from ۱۴.۶% to ۲۲.۲%), and CH۴ (from ۱.۷۵% to ۱.۸۵%) compared to nonpreheating air. Preheating of air also increased the value of LHV (from ۴۶۰۰ to ۶۰۵۳ kJ/kg). The CGE and CCE were increased from ۶۸ to ۶۹% and ۸۵ to ۹۳%, respectively, at the preheating temperature of ۲۱۰ °C. Conclusion: The results of this study can be used to optimize the performance of multistage gasifier using air preheating and multistage air inlets.

Keywords:

MSW , Gasification , RDF , Gasifier , Multistage