Towards sustainable biomass gasification: Evolution of bagasse char characteristics throughout gasification

Abstract

The development of a sustainable bagasse gasification system using bagasse as feedstock could be realized if a complete understanding of bagasse gasification was established. In this study, the evolution of the char characteristics throughout the gasification process was deeply investigated. The low ash content, high heating value, and fast char conversion rate highlighted the suitability of bagasse for gasification. The char morphology underwent significant changes with rupture of beehive-like structures that make up the char when conversion X [0, 1] is higher than 0.5. On the contrary, changes in carbon structures were observed more clearly at the beginning of char conversion (X < 0.5). The gasified chars had high porosity made of micro-mesoporous structures, and the maximum value of total specific surface area (SBET = 877 m2 g−1) and total pore volume (VBET = 0.49 cm3 g−1) were observed at X = 0.75. The high values of SBET and VBET - even when gasification is nearing its end - highlighted the potential of using residues after gasification as an alternative to expensive commercial activated carbons. The results of this study would contribute to forming solutions for some challenges for the industrialization of biomass gasification, such as the formation of soot and tar, or the treatment/reuse of post-gasification residues.