The chemical looping technology applying to waste plastics treatment was developed in this project. The advantages of high conversion of organic species and low energy consumption of chemical looping technology are benefit to treat waste plastics more efficiently. The key techniques including preparation of oxygen carrier, transportation of oxygen carriers between fuel and air reactors and optimal design for waste plastics treatment are essential for development of waste plastic combustion by chemical looping process. The Fe-based composite oxygen carrier was feasible for chemical looping process through preliminary tests by thermogravimetric analysis, fixed-bed reactor and mechanical strength prior to moving bed experiment. Polyurethane (PU) and polypropylene (PP) were used for solid fuels as well as treated plastics in this study. The enthalpies of PU and PP were quite high to employ as fuels for combustion. Besides, gasification of PU and PP particles with empty bed operation were conducted by using CO2/O2 as gasification reactants at 900°C. The components of gaseous fuels were mainly CO and H2. Therefore, PU and PP particles would be decomposed and gasified to be gaseous fuels prior to combustion with oxygen carriers. Finally, PU and PP particles were combusted by the moving bed reactor system developed in this project, and trying to find out the appropriate operation condition in terms of PU and PP combustion and long-term operation to verify the reliability of reactor system. The Fe-based composite oxygen carrier developed for moving bed reactor operation provided with well reactivity, recyclability and strong mechanical strength. The suitable gasification conditions of PU and PP particles were found by empty bed experiments, and applied to the combustion experiments in moving bed experiments. Complete combustion of PU and PP particles were achieved by combusted with Fe-based composite oxygen carrier in moving bed reactor. The combustion performance of moving bed reactor was evaluated for scaling up. Long-term operation for PU and PP particles combustion was last for 24 hours, and 100% of CO2 yield was stably reached.

chemical looping process;waste plastics;oxygen carrier