The Influence of Feedstock Variability on Syngas Quality and the Viability of Municipal Solid Waste Gasification in a Developing World Context

Abstract ―​

This research examines the impact of municipal solid waste (MSW) feedstock variability on syngas quality and the overall feasibility of gasification technology in a developing country environment, using Port Harcourt, Nigeria, as a case study. Three unique versions of municipal solid waste feedstock—Biogenic-Rich (Mix A), Plastic-Rich (Mix B), and High-Moisture (Mix C)—were created, characterised, and subjected to gasification in a laboratory-scale reactor under optimised conditions (950°C, Equivalence Ratio=0.30). The findings indicate that feedstock composition significantly influences syngas quality and system efficacy. Mix B, the Plastic-Rich feedstock, generated syngas with the greatest Lower Heating Value (LHV of 7.05 MJ/Nm³), but also resulted in markedly elevated tar levels (5.5 g/Nm³) and caustic HCl (450 mg/Nm³). The High-Moisture feedstock (Mix C) significantly decreased cold gas efficiency to 53.1% because of the energy cost associated with water evaporation. Conversely, the Biogenic-Rich feedstock (Mix A) yielded the most equilibrated and stable performance, achieving a cold gas efficiency of 72.8% and producing more controllable tar by-products. A preliminary techno-economic study estimates a net profit of $75–85 per tonne of municipal solid waste processed and a payback time of 4–5 years, bolstered by dual income streams from energy sales and avoided landfill costs. The environmental study reveals a net decrease of around 1.1 tCO₂e per tonne of municipal solid waste (MSW). The research indicates that while MSW gasification is both technically and economically feasible, its success depends on thorough feedstock characterisation and preparation, with a strong suggestion to focus on the biogenic portion for smaller-scale, dependable deployment in developing areas.