Siderite/Concrete catalysts for H2-enriched gas production from biomass steam gasification

• Main Author: Ruivo, Luis
• Publication Date: 2022
• Other Authors: Oliveira, Hortência, Gomes, Helena, Cruz, Nuno, Yaremchenko, Aleksey, Tarelho, Luís A.C., Frade, Jorge
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10773/35803
• topic: Biomass; Gasification; Catalyst; Siderite; Concrete

In this study, granulated siderite/concrete-based catalysts are proposed for in-situ applications in biomass steam gasification, seeking H2-enrichement by the contribution of water gas shift and CO2 adsorption. A cost-effective procedure has been applied for the preparation of granulated catalysts. Water Gas Shift reaction was studied in a fixed bed reactor and Taguchi experimental design was used to elucidate the relevance of experimental parameters on catalyst performance. The results show that the impact of reaction temperature, concrete/siderite ratio and steam to carbon molar ratio on H2 promotion had the following order: reaction temperature (43.1 %), concrete/siderite ratio (30.2 %) and steam to carbon molar ratio (26.7 %). Additionally, the catalyst exhibited high activity when integrated into the freeboard zone of a bubbling fluidized bed gasifier. Compared to the reference condition, one observed significant impact at 700 ºC on the H2:CO ratio (1.9 to 3.3), H2 production (33.8 to 48.6 g_(H2)∙kg_(dry,fuel)^(-1)), carbon conversion efficiency (54.1 to 58.6 %) and cold gas efficiency (55.0 to 60.9 %). Though the catalyst exhibited resistance to sintering, post-mortem analysis suggests loss of active species after repeated cycles of regeneration due to thermal-induced stresses, which caused gradual decrease in activity.