Supercritical water gasification of fruit pulp for hydrogen production: Effect of reaction parameters

Abstract

Supercritical water gasification (SCWG) is a promising technology for converting high moisture biomass into valuable gas products. In this study, SCWG of fruit pulp was carried out in a batch reactor in the presence of KOH catalyst. The effect of reaction parameters such as temperature (400-600 degrees C), reaction time (30-180 min), biomass ratio (2.5-10%, wt. biomass/wt. water) and KOH ratio (0-30%, wt. catalyst/wt. biomass) were inves-tigated in order to determine the suitable reaction conditions for maximizing H-2 yield. The maximum H-2 yield (32.1 mol/kg biomass) was achieved at 600 degrees C, 30 min, 2.5% biomass ratio and 10% KOH loading. The experimental results indicated that KOH could promote biomass decomposition and increase the amount of gas products via the water-gas shift reaction (WGSR) by intermediate formation of salts and suppressing the char and tar formation. KOH also played a sufficient role in capturing CO2 at high temperatures, proceeding the WGSR equilibrium reaction towards the products resulting in the production of more hydrogen.