Effect of fuel particle size and blending ratio on syngas production and performance of co-gasification

Shortage of feedstock supply often happens in biomass gasification. Thus, the co-gasification of blended biomass is a potential option to maintain feedstock supply for continuous gasification operations. The aim of this study is to investigate the effects of biomass blending ratio and biomass particle size on the syngas quality and performance of the co-gasification process. The co-gasification of wood chips/coconut shells was carried out in a downdraft gasifier at a 400 L/min airflow rate. The biomass blending ratio varies at 80/20, 50/50 and 20/80 (w/w) with biomass particle sizes of 5-10, 10-25 and 25-50 mm. The results show that small particle size favours gas composition. The highest H<inf>2</inf> (10.91%), CO (25.60%), and CH<inf>4</inf> (2.79%) levels were obtained from the 5-10 mm particle size at 80/20, 50/50, and 20/80 blending ratios, respectively. Higher HHV and gas yield were obtained at the 20/80 blending ratio with the 5-10 and 10-25 mm particle sizes, respectively. Cold gas efficiency varies from 54.37 to 65.52%. The trend shows that at smaller particle sizes, cold gas efficiency is higher, while in most cases, carbon conversion efficiency was found to be more than 90% during co-gasification. The syngas quality and performance of co-gasification were more sensitive to biomass particle size as compared to the blending ratio.