Effect of combined slow pyrolysis and steam gasification of sugarcane bagasse on hydrogen generation

Abstract

The present work aims at improving the generation of H2 from sugarcane bagasse in steam gasification process by incorporating slow pyrolysis technique. As a bench scale study, slow pyrolysis of sugarcane bagasse is performed at various pyrolysis temperature (350, 400, 450, 500 and 550 °C) and feed particle size (90<DP<212, 212< DP<355, 355<DP<500, 500<DP<850 µm) to determine effective conditions of char generation. In the combined process (slow pyrolysis of biomass followed by steam gasification of char), first slow pyrolysis is carried out at the effective conditions (pyrolysis temperature and particle size) of char generation (determined from bench scale study) and steam gasification is at varying gasification temperature (600, 650, 700, 750 and 800 °C) and steam to biomass (S/B) ratio (1, 2, 3, 4, 5 and 6) to determine the effective conditions of H2 generation. The effect of temperature and S/B on gas product composition and overall product gas volume was also investigated. At effective conditions (gasification temperature and S/B) of H2 generation, individual slow pyrolysis and steam gasification were also experimented to evaluate the performance of combined process. The effective condition of H2 generation in combined process was found to be 800 °C (gasification temperature) and 5 (S/B), respectively. The combined process produced 35.90% and 23.60% more gas volume (overall) than slow pyrolysis and steam gasification process, respectively. With respect to H2 composition, the combined process generated 72.37% more than slow pyrolysis and 17.91% more than steam gasification process.