Experimental Investigation of Syngas Production from Co-Gasification of Municipal Solid Waste and Agricultural Residues in Kaduna State

Co-gasification of municipal solid waste and agricultural residues offers a dual waste management and renewable energy opportunity for Kaduna State, North West Nigeria, where both waste streams are generated in substantial quantities. This study experimentally investigates the co-gasification of municipal solid waste from Kaduna North with cotton stalk from Zaria in a downdraft fixed-bed gasifier at blending ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 by weight. Equivalence ratio was varied between 0.20 and 0.35 using air as the gasification agent. Product syngas composition was determined by gas chromatography, and cold gas efficiency, lower heating value, and tar content were measured at each test condition. Municipal solid waste gasification alone produced low hydrogen content (8.4%) and high tar (28 g/Nm3), limiting syngas quality. Co-gasification with 50% cotton stalk significantly improved hydrogen content (14.7%) and reduced tar to 9.4 g/Nm3 at an equivalence ratio of 0.27. Cold gas efficiency peaked at 68.3% for the 50:50 blend at an equivalence ratio of 0.27. Carbon conversion efficiency improved monotonically with cotton stalk content. The study identifies the 50:50 blend at equivalence ratio 0.27 as the optimal operating condition, providing a syngas with a lower heating value of 4.8 MJ/Nm3 suitable for electricity generation via internal combustion engines in Kaduna State. Keywords: co-gasification, municipal solid waste, cotton stalk, syngas, Kaduna State