Design and experimental study of solar-driven biomass gasification based on direct irradiation solar thermochemical reactor

Abstract

Solar-driven biomass steam gasification is a promising technology to produce H₂-rich syngas, meanwhile achieve flexible storage of renewable energy. However, the solar gasification application also faces numerous challenges, due to its involved complex chemical reaction characteristics and the inherent the multi-physics energy conversion processes. This work designs a novel direct irradiation solar gasification reactor, with the improved optical acceptance structure and reasonable test module, and the wheat straw particle is selected as experimental sample. Employing a 9 kW_e high flux solar simulator, the maximum temperature of reaction bed in this prototype reactor reaches to 1260 °C, with the average solar flux of 1171.3 kW/m². With adjustable radiation flux as experiment factor, under the highest total radiation of 3.35 kW, the molar fraction of H₂ in the produced syngas is 47.1 % with the energy upgrade factor of 1.15, and the cellulose component completes decomposition. Increasing the mass flow rate of steam reduces the syngas output while raising the H₂/CO ratio of the syngas. In addition, smaller biomass particle size facilitates the reaction, thereby improving the conversion efficiency of direct irradiation gasification. The investigation results provide a meaningful reference for the efficient utilization of abundant solar and biomass energy.