Experimental And Simulation Study On The Gasification Of Municipal Polyethylene Plastic In Fluidized Bed

Recycling and gasification of plastic film waste which mainly consists of polyethylene has been developed to one way to solve the increasingly serious environmental issues. This thesis aims at laying a foundation for the designing of bubbling fluidized bed gasifier. The gasification pilot plant and experiments has been introduced and an Eulerian-Eulerian approach for the interaction of gas-solid phase, associated with the Kinetic Theory of Granular Flow model(KTGF model) and a proper gasification reaction model was adopted to simulate the process of gasification. The simulation results are compared with experiment. All of the work has laid a foundation for establishing a better plastic film waste gasification model and the designing, optimization, expansion of the bubbling bed gasifier.Through the cold flow experiments and simulation, principal flow regimes for upward flow of different air artificial velocity trough solid particulate materials was observed and the air artificial velocity for bubbling fluidization was found out. Meanwhile the bubbles' periodically producing, growing up, coalescing and breaking up was observed through the simulations. Besides, the influence of the laminar flow model and turbulent flow model to the simulation results were taken into consideration.Through the gasification simulation and gasification experiments, the influence of different ER ratio to the final gas production has been conducted and discussed. According to the results, A higher ER ratio lead to a lower HHV of gas production, and the proper ER ratio for a high HHV was 0.25. According to analysis of simulation results, an optimized structure model of bubbling fluidized bed gasifier was established and simulated to get access to a better result.