Ruming Pan is an Associate Professor at Harbin Institute of Technology, China. He earned his Ph.D. from Toulouse INP in France and focuses on reactive porous media, solid waste valorization, and solar thermochemical processes. An award-winning researcher, he has delivered keynote talks and serves as a Youth Editorial Board Member of Rare Metals. He has authored 34 journal papers and holds three Chinese patents.
The growing global energy demand and increasing environmental challenges have accelerated research into renewable energy utilization technologies. Biomass and solar energy, as promising renewable resources, can be combined through solar-driven pyrolysis/gasification for producing biofuels and biochar. This study reviews comprehensive numerical simulation methods for solar-driven biomass thermochemical conversion, focusing on solar heat source treatment methods, the equivalent porous media model of heat and mass transfer, and common reaction kinetics models. Three principal solar heat source modeling approaches are examined: temperature boundary, heat flux boundary, and Monte Carlo ray tracing (MCRT), with MCRT providing superior accuracy in capturing directional radiation in complex reactor geometries. The thermal analysis incorporates local thermal equilibrium (LTE) and local thermal non-equilibrium (LTNE) approaches within the equivalent porous media model, along with the radiative transfer models including the Rosseland approximation, P1 approximation, and Discrete Ordinates (DO) method. LTNE is crucial for systems with pronounced solid-fluid temperature gradients, while the Rosseland and P1 approximation provide the efficient computational methods for media with high optical thickness. Three fundamental reaction kinetics models are presented for biomass pyrolysis: single-component single-step, single-component multistep, and multicomponent multistep reaction kinetic models. Multistep reaction kinetics models are shown to capture intermediate pathways and product distributions more realistically than single-step approaches. The numerical model coupling multi-physical fields can provide a solid theoretical basis for optimizing reactor design, regulating target products, and enhancing energy conversion efficiency. Future research should integrate high-fidelity simulations with experimental validation to enhance predictive accuracy and support scale-up of solar-driven biomass conversion systems.
Part of the book: Progress on Porous Media Research
Solar energy, as a renewable energy source currently attracting much attention in the energy field, is of great significance for its effective utilization and conversion for environmental protection and energy industry development. This study proposes a solar-driven photothermal reactor and establishes a mathematical model coupled with multi-physical fields. Specifically, the radiative transfer of the numerical model takes into account different wavelengths to improve the simulation accuracy. Further, the effects of operating condition parameters such as xenon lamp power, inlet flow rate, and foam’s porosity and pore diameter on the photothermal field performance in the reactor were comparatively analyzed. The results showed that lower xenon lamp power, higher inlet flow rate, and smaller foam’s porosity and pore diameter could improve the photothermal (fluid) energy conversion rate of the solar reactor. The findings contribute to diversifying solar energy utilization strategies and support future efforts to optimize reactor energy conversion performance.
Part of the book: Advanced Foams for Process Intensification