From Sunlight to Syngas: enabling Solar-enhanced Biomass Gasification through Thermal Energy Storage Integration

Integrating solar energy with biomass gasification presents a promising approach for sustainable fuel production with enhanced efficiency. Concentrated Solar Power (CSP) as an external heat source for biomass gasification offers many advantages, such as reducing the equivalence ratio and fuel gas usage for endothermic reactions, resulting in increased syngas quality in terms of Lower Heating Value and hydrogen content. Thanks to this integration, the net gasification efficiency may increase by 10-24%, depending on the biomass type and composition. Additionally, this integration reduces gas cleaning and separation costs, as combustion-derived pollutants are minimized. This paper presents a novel concept for small-scale solar-assisted biomass gasifiers (SABG), where heat management is achieved through three combined strategies: 1) pre-heating the gasification agent (air) in the CSP receiver and directly supplying it to the gasification reactor, 2) thermal storage in a solid packed bed, and (dry rocks thermal storage DRTES), 3) regulation of the gasification agent flow rate. The paper analyses this configuration with a time-step simulation based on real meteorological data, to evaluate the energy gain obtained with a CSP+DRTES SABG design. The annual thermal-to-syngas conversion efficiency compared to the baseline configuration increases in the range 10.9%-17.5% according to the specific scenario set for the simulation.