Solar Pyro-Gasification of Biomass: Modelling the Influence of Moisture Content and Sample Height

A comprehensive computational fluid dynamics model was developed to analyse the solar pyro-gasification of thermally thick biomass particles, with particular emphasis on the effects of initial moisture content and sample height on product yields and syngas composition. The model incorporates moisture evaporation, primary pyrolysis reactions, secondary tar cracking, and both homogeneous and heterogeneous gasification reactions. Kinetic parameters for secondary tar cracking reactions were derived using Reactive Molecular Dynamics simulations, improving the accuracy of reaction kinetics predictions at high temperatures. The model was successfully validated against experimental data available in the literature for various final temperatures (800?1600 °C) and heating rates (10 and 50 °C/s). Results demonstrated that higher moisture content promoted steam reforming reactions and increased the syngas yield, particularly hydrogen (H2) and carbon monoxide (CO), while also significantly influencing the pyrolysis kinetics and product distribution. Also, increased sample height intensified intra-particle secondary reactions due to extended residence times, impacting both gas yields and compositions. This model represents a significant step forward in understanding and optimizing the solar pyrolysis process for thermally thick biomass particles. Fil: Soria, Jose Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina Fil: Mazza, German Delfor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina