EUBCE 2026 - Julie MICHEL - Influence of the Inorganics on Catalyst During Supercritical Water Gasification of Biomass

Influence of the Inorganics on Catalyst During Supercritical Water Gasification of Biomass

Short Introductive summary

Biomass gasification allows to convert carbon into biogas by thermal treatment. Supercritical water gasification (SCWG) allows to convert flexible type of feedstock into gases, by heating it immerged in supercritical water. However, due to the significant decrease of its dielectric constant, some inorganic salts naturally present in biomass precipitate, which can clog the reactor pipes and poison the catalyst. In the other hand, some inorganic salts have catalytic properties that favour the gasification and enhance gas selectivity. Hence, it is essential to understand how the salts affects the mechanisms to optimise the process, including a salt separation if needed beforehand. This study focuses on the role of the inorganic salts during the catalytic SCWG. To observe the catalyst efficiency, commercial Raney nickel is used on the SCWG of two model molecules: acetic acid and furfural. Both these molecules are known to be reluctant to SCWG and are consequently often observed as liquid end products when lignocellulosic biomasses are gasified. At last, 4 salts were selected, due to their different behaviour under supercritical water: K2CO3, Na2CO3, K3PO4 and Na3PO4.

J. Michel, CEA, Grenoble, FRANCE
H. Demey, CEA, Grenoble, FRANCE
A. Chappaz, CEA, Grenoble, FRANCE