Influence of promoted bimetallic Ni-based catalysts and Micro/Mesopores carbonaceous supports for biomass hydrothermal conversion to H2-rich gas

Abstract

We report herein, a green route of energy generation from lignocellulosic wastes, the production of H2 from catalytic hydrothermal gasification of Iranian canola stalks (CS). Firstly, we performed the non-catalytic tests in a stainless-steel batch micro reactor to determine the impacts of operational parameters (temperature, time and feedstock concentration) and optimize them. The achieved optimized control factors were found to be 440 °C and 20 min, and 2.5 wt% for temperature, reaction time, and feed concentration, respectively. Furthermore, the optimum control factors were used to examine the impacts of Ni catalysts supported on two different supports (activated carbon (AC) and Graphene Nano sheets (GNS)) on the mole fractions and yields of H2 in details. Hence, we investigated the impacts of novel bimetallic catalysts, (Ni-Ru, Ni-Co, and Ni-Cu) supported on GNS for the first time and the optimized catalyst promoter was also impregnated separately on AC to improve and achieve the highest H2 yield possible. Among the prepared catalysts, the Ni-Cu/AC catalyst showed the best performance with the highest H2 gas yield and lowest methane production of 20.96 and 2.19 (mmolgas. g−1CS), respectively. H2 gas production was monitored during the HTG process using gas chromatography and the physiochemical properties of the prepared catalysts were also examined by various techniques.