Study On MSW Fluidized-Bed Gasification And Melting Technology

Nowadays, environmental pollution and resource shortage are the two serious puzzles for stable development. "Circular Economy" and "Sustainable Development" are advocated by the government. It is a great opportunity to develop municipal solid waste(MSW) gasification and melting technology in China. Drived by the requirments, MSW fluidized-bed gasification and melting technology was proposed and researched.After a general review of MSW characteristics, thermodynamic analysises were carried out. Fluidized-bed gasification and melting process was advanced. In this process, MSW was sieved firstly; the part above the sieve was gasified in a fluidized bed, then the products were combusted and fly ash was melted in a swirl furnace.A lab-scale fluidized-bed gasifier was built to study the gasification characteristics of typical components and simulative MSW. The experiments were fulfilled at 400-800°C when excess air ratio was 0.2-0.8. The characteristics were analyzed detailedly, such as the heat value of gasification products, the efficiency of energy conversion, the heat value of cooled syngas, the gasification efficiency, the carbon conversion efficiency, the yield of gasification and the components in the syngas. Based on the results, an artifical neural networks was built up to forecast the main characteristics of MSW gasification.Experiments were fulfilled in a fixed-bed melting furnace to research the melting point of MSW combustion ash, the decomposed characteristics of dioxins and the fixed efficiency of heavy-metals in slag, which were important data for melting furnace design.The simulation software, Fluent, was used to simulate the combustion of gasification products and the track of slag in melting furnace. According to the results, some advises were brought forward for the design of melting furnace.Based on the researches above, a commercial-scale sketch of fluidized-bed gasification and melting system was proposed.