(752e) Solar Gasification of Organic Solid Waste in an Internally-Circulated Fluidized Bed: Experiment and Modelling

Solar gasification is a promising and efficient approach to convert organic solid waste to high-quality syngas due to solar energy stored. Previous research outcomes of internally circulating fluidized beds have demonstrated that circulating particles inside the reaction bed is able to significantly enhance heat and mass transfer and to mitigate surface hot spots caused by non-uniform concentrated solar fluxes. In this work, a clapboard-type internally-circulating fluidized bed with an indirectly irradiated structure is experimentally studied via Singapore’s first 28-kW_e high-flux solar simulator. Three different kinds of organic solid waste e.g. charcoal, chicken manure, and horticultural waste are tested under CO₂ gasification. Different experimental conditions are considered in experiment: (i) the effect of different radiated power inputs on heating rates, and (ii) the effects of the CO₂/C ratio and the bed mass on the solar upgrade factor and solar conversion efficiency. Since solar gasification operates in high-temperature solar reactors, it is difficult to adopt conventional techniques e.g. magnetic resonance imaging, particle image velocimetry, electrical capacitance tomography, etc. to investigate the fluid dynamic characteristics. Considering non-uniform solar fluxes obtained by optical calibration, a 3D numerical model is developed to indicate granular flow transport and heat transfer behaviors in solar gasification processes. This work contributes a holistic research outcome to the indirectly irradiated solar gasification of organic solid waste.