Experimental Studies on Synthesis Gas Production from Wood Wastes in a Pilot Downdraft Gasifier

Abstract

Gasification is a green technology, which produces combustible gas mixture from solid biomass by partial oxidation at elevated temperatures. Synthesis gas, the desired product of such technology, has more uses than the solid biomass. In this study, a locally developed pilot scale fixed-bed downdraft biomass gasifier was examined. Several gasification experiments using mixed wood wastes (generated from the utilisation of various wood species for making furniture) as feedstock was carried out under varied operating conditions to ascertain their effects on the syngas produced in the process. The effects of grate temperatures and biomass moisture levels on rate of biomass consumption and produced syngas quality were examined via several gasification experiments. The performance of the biomass gasifier system was evaluated in terms of syngas composition, lower heating value, syngas yield and carbon conversion efficiency. The results obtained revealed an average syngas yield of 1.77Nm3 per kg of wood waste consumed. The averaged molar syngas composition obtained was 28.15% CO, 16.64% H2, 6.19% CO2, 2.54% CH4 and 45.42% N2, while the average syngas LHV was 6.23MJ/Nm3. These results were compared with those published in literature.