Biomass treatment and upcycling is attracting considerable critical attention. Upcycling is a converting procedure to alter a valueless or low-value product to another form with higher value, and in this regard, biomass gasification is an upcycling process which converts biomass into a hydrogen-rich syngas. In recent years, researchers have shown an increased interest in biomass gasification; however, there is a lack of a comprehensive and systematic research considering simultaneously various biomass types and gasifying mediums. This study set out to simultaneously consider twenty biomass types and three gasifying mediums and perform a systematic multi-criteria decision analysis to select the best coupling of biomass type/gasifying medium considering nine criteria of syngas compositions and different efficiencies. Biomass types were ranked using the technique for order of preference by similarity to ideal solution method for each gasifying medium, and a sensitivity analysis was performed to select the first and second biomass types with respect to different criteria weights. Performance of gasification processes was multi-objective optimized using response surface methodology. A systematic multi-criteria decision analysis and a sensitivity analysis were conducted to choose the best gasification performance of the best biomass types in their optimum conditions. The findings revealed that gasification with a steam gasifying agent by pine sawdust biomass had the best performance and produced 46.96% of hydrogen and only 4.99% of carbon dioxide and led to energy and exergy efficiencies of 80.91% and 86.03%, respectively. The findings can contribute to a better understanding of the biomass gasification process with different feedstocks and agents.
