The effect of thermal pre-Treatment on cassava rhizome properties for utilizing as green fuel in gasification

Abstract

Cassava rhizome (CR) was torrefied to provide superior solid fuel quality for further gasification process. The torrefaction was carried out in the absence of oxygen at 220, 240, 260, and 280°C with a fixed residence time. Solid fuel after torrefaction has a higher calorific value from that of reduced volatile matters. The optimum energy yield of torrefied CR is 88.16% at 260°C. The heating value of 20.86 MJ/kg for a torrefied product can be achieved compared to 15.37 MJ/kg for untreated CR. The subsequent gasification of torrefied CR at temperature of 800°C yielded the highest gas product of 65 wt.%. The carbon and hydrogen conversions into CO and H2 were 14.28% and 29.95%, respectively. Synthesis gas (syngas) from the conversion maintained the H2/CO ratio of around 2-2.50, which is suitable for the Fischer-Tropsch process or can be used as the feedstock for petrochemical industry.