Electricity Power Generation from Co-Gasification of Municipal Solid Wastes and Biomass: Generation and Emission Performance

Global generation of municipal solid waste (MSW) is predicted to reach over 2.2 billion tons/year in 2025. Landfilling and incineration, the two most common conventional techniques for MSW processing, negatively impact public health. This study developed and demonstrated electricity generation by co-gasification of two underutilized resources: MSW and agricultural biomass. A patented design of 60-kW downdraft gasifier and an internal combustion engine with 10 kW generator were used to generate electricity from co-gasification of various ratios of MSW and biomass. The maximum heating values (LHV) of syngas obtained at MSW ratio of 0, 20, and 40 wt.% were 6.91, 7.74, and 6.78 MJ/Nm³, respectively. At all MSW to biomass ratios, the maximum electric load generated was 5 kW, with electrical efficiencies of 22, 20, and 19.5% at MSW ratios of 0, 20, and 40 wt.%, respectively. The engine CO, NO_x, SO₂, and CO₂ emission decreased with increasing load, while HC emission increased with increasing load. CO, NO_x, and CO₂ emissions decreased, while HC and SO₂ emissions increased with increase in MSW ratio. Thus, the co-gasification system provides a basis for future development of small-scale power generation to utilize local wastes.