CFD-DEM simulations of municipal solid waste gasification in a pilot-scale direct-melting furnace

A multiphase CFD-DEM model was built to simulate the waste-to-energy gasifying and direct melting furnace in a pilot demonstration facility. The characterizations of feedstocks, waste pyrolysis kinetics, and charcoal com-bustion kinetics were first obtained in the laboratory and used as model inputs. The density and heat capacity of waste and charcoal particles were then modelled dynamically under different status, composition, and tem-perature. A simplified ash melting model was developed to track the final fate of waste particles. The simulation results were in good agreement with the site observations in both temperature and slag/fly-ash generations, verifying the CFD-DEM model settings and gas-particle dynamics. More importantly, the 3-D simulations quantified and visualized the individual functioning zones in the direct-melting gasifier as well as the dynamic changes throughout the whole lifetime of waste particles, which is otherwise technically unachievable for direct plant observations. Hence, the study demonstrates that the established CFD-DEM model together with the developed simulation procedures can be used as a tool for the optimisation of operating conditions and scaled-up design for future prototype waste-to-energy gasifying and direct melting furnace.

Automated summary

A multiphase CFD-DEM model was developed to simulate a waste-to-energy gasifying and direct melting furnace. The model used characterizations from laboratory experiments to dynamically simulate the density, heat capacity, and fate of waste and charcoal particles under different conditions. The simulation results matched well with site observations, providing insights into the functioning zones and dynamic changes within the furnace. The study demonstrates the utility of the model for optimizing operating conditions and scaled-up design for future waste-to-energy facilities.