Solar-thermal conversion of biomass: Principles of solar concentrators/reactors, reported studies, and prospects for large-scale implementation

Solar-thermal biomass conversion using both direct and indirect concentrated solar thermal energy is an emerging approach that combines two renewable energy sources to enhance energy efficiency and enable sustainable processing. This review paper provides a comprehensive examination of various types of solar concentrators and reactors, showcasing the diversity of available technologies and their roles in enhancing conversion efficiency. The paper focuses on the reported studies on biomass solar-thermal conversion through gasification and pyrolysis processes, critically discussing the integrated process operating conditions and the quality of the products (biofuels). These analyses affirm the technical viability, emphasizing the relatively low energy investment required for pyrolysis compared to the total energy output from biomass feedstock. This points to the substantial promise of solar thermal biomass conversion as a sustainable and efficient renewable energy solution. The conclusion highlights the importance of ongoing research, technological advancements, and policy support to fully realize the potential of solar-thermal conversion of biomass.