Abstract:
Shortage of feedstock supply often happens in biomass gasification. Thus, the cogasification
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 H2
(10.91%), CO (25.60%), and CH4 (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.