Gasifier for Plastic Waste Using High-Temperature Superheated Steam

In this study, gasification experiments of polyethylene (PE) samples were conducted under various conditions using superheated steam to produce gas fuel from plastic waste, and the amount of gas produced, gas composition, carbon conversion ratio, and cold gas efficiency were evaluated to clarify the trends. Moreover, a business model was proposed to further extend the research. From the experiments, it was clarified that in the gasification of PE samples under different superheated steam temperatures, the amount of gas produced decreases, the concentration of hydrocarbon components in the gasification gas increases, and the carbon conversion rate decreases with a decrease in temperature. The results suggest that the reason for this change is a decrease in the amount of steam reforming reaction due to the decrease in the temperature of the system. In addition, the effect of residence time in the system on the gasification reaction process under unsteady conditions was clarified by comparing the results of the mol ratio of carbon to water vapour (S/C) change in which the PE sample feed rate was continuously changed with the equilibrium calculations for CH4 and C2H4. Finally, the equipment developed in this study has led to the possibility of developing a thermal energy recovery business for plastics waste that can reduce environmental impact, disposal costs, and energy consumption in islands and coastal areas that have problems with the disposal of drifted garbage.