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 0.4 and 0.66, respectively, which have been tested for the effect of PAT (from 100 to 210°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 17.3% to 26.2%), H2 (from 14.6% to 22.2%), and CH4 (from 1.75% to 1.85%) compared to nonpreheating air. Preheating of air also increased the value of LHV (from 4600 to 6053 kJ/kg). The CGE and CCE were increased from 68 to 69% and 85 to 93%, respectively, at the preheating temperature of 210 °C.
Conclusion: The results of this study can be used to optimize the performance of multistage gasifier using air preheating and multistage air inlets.