The integration of low temperature supercritical water gasification with continuous in situ nano-catalyst synthesis for hydrogen generation from biomass wastewater

A continuous hydrothermal process is demonstrated, for the first time, that can operate at low gasification temperature (430 °C) and residence time (20 s) by combining supercritical water (SCWG) partial oxidation with in situ synthesis of virgin metal oxide nano-catalyst. Using olive wastewater as feedstock, this study experimentally investigated impact multiple variables: (1) COD feed concentration, (2) different nano-catalysts, (3) coefficient (?) (4) nano-catalyst precursor solution concentration. The optimum conditions generation hydrogen methane from were a 38.6 g/L, ? = 0.8, 60 mM concentration Fe2O3 These optimised further using spent lees stillage. efficiency yields reduction order stillage > wastewater. highest molar selectivity, 18.8 %, 17 11.4 mol/(kg biomass) respectively obtained feedstock. Gasification, TOC efficiencies 68.8–71.7 72.6–76.5 % 53.9–55.7 respectively, process. Importantly, novel approach prevents any performance drop or catalyst deactivation during operation. This exemplifies co-generation SCWG promising economically feasible direction large-scale types biomass < 450 °C, whilst lowering its TOC. (249 words)