Feasibility Study of Maize Cobs as Throatless Gasifier Feedstock

Fuel properties of maize cob and its gasification feasibility in throatless downdraft gasifier were investigated. Performance of the throatless gasifier using producer gas from maize cobs was evaluated in terms of fuel consumption rate, heating value of producer gas and gasification efficiency at different gas flow rates. Gasification efficiency increased with increasing gas flow rate, and was maximum (67.37%) at specific gasification rate (SGR) of 169.95 kg.h⁻¹.m⁻² and gas flow of 33.02 Nm³.h⁻¹. Further increase in gas flow rate reduced gasification efficiency. Energy balance for the run had maximum efficiency. Each unit of energy input to the gasifier in the form of maize cobs was converted to 67.18% chemical energy of producer gas and 16.82% char residue, respectively. Sensible energy of gas and char residue was 6.51% and 0.11%, respectively. The unaccounted losses were 9.38 per cent. Maize cobs could thus be successfully used as feedstock for throatless gasifier.