Gasification of untreated and pretreated coconut shell (CS) was carried out in a fixed-bed reactor to assess the effect of temperature (600, 650, 700, 750, and 800 C) and holding time (30 and 40 min) on gases composition. The untreated CS was first torrefied in a fixed-bed reactor at different temperatures (200 รข 300 C) and holding times (30 min, 60 min and 90 min). Pretreated CS at the optimal torrefaction temperature (275 C and 60 min) was used for gasification. Under optimal conditions of 750 C and 30 min holding time, gasification contributed the most gas production. At this optimum condition, the gas composition of pretreated CS was 35.03 % of CH4, 24.43 % of CO2, and 40.54 % of H2 + CO. Untreated CS contains 37.63 % of CH4, 24.03 % of CO2, and 38.34 % of H2 + CO gases. The production of CH4 gas was higher when untreated CS was used for gasification rather than pretreated CS. Moreover, when untreated CS was used for gasification, the amount of CO2, H2, and CO produced was minimal. Therefore, for high H2 production, pretreatment prior to gasification is appropriate.
