Microwave Chemical Looping Synergistic Gasification of Polypropylene Plastic and Water Hyacinth

The microwave chemical looping synergistic gasification characteristics of municipal solid waste polypropylene plastic and the organic solid waste water hyacinth are experimentally investigated in this study. In addition, the characterizations of oxygen carriers before and after the reaction are combined to analyze the evolution of the microscopic morphology of oxygen carriers and the changes in the relative contents of each valence state of Fe and O elements. The results show that an increase in the water hyacinth mixing ratio presents positive effects on tar cracking and a slight negative effect on syngas yield. At the water hyacinth mixing ratio of 75%, the cold gas efficiency and carbon conversion can reach maximum values of 77.64% and 69.9%, respectively. The H2 yield and H2/CO ratio in syngas can be also improved to 0.34 Nm3/kg and 1.62, respectively. In addition, a minimum tar yield of 0.133 g/g (fuel) can be obtained at this mixing ratio. Moreover, the addition of water hyacinth has a continuous increase effect on monocyclic aromatic hydrocarbon (MAH) products of tar, and a continuous decrease effect on naphthalene and bicyclic aromatic hydrocarbons (NAH) products. This work explores the synergistic properties of organic waste plastics and agroforestry wastes during microwave chemical looping gasification, which is a useful exploration for solving the environmental problems caused by waste materials and agroforestry wastes as well as realizing the resourceful utilization of solid wastes.