Plastic Waste Upgrading by Coupling Microwave Heating with Catalytic Pyrolysis

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My proposed research focuses on the circular economy wherein process electrification is coupled with catalytic pyrolysis to solve one of the emerging and serious environmental issues: Plastic wastes. The circular economy is a decent alternative to the linear economy of the value chain due to the depletion of conventional and easily processable resources as well as the increasing stringent environmental regulations. By doing so, Canadians would greatly benefit from a better utilization (and valorization) of waste. It would improve Canada's environmental performance, offer new revenue streams for its industries and make its industries more competitive. To utilize and valorize waste, recycling is not always techno-economically possible due to cross-contamination and limitations of waste separation processes. Electrification of the process industries lies in the context of the 4th industrial revolution. Knowing the electricity is a renewable and clean energy resource, its implementation onto the process industries would provide benefits in terms of environment protection, enhanced productivity, and business growth. In this context, there are significant advantages attributed to microwave heating assisted processes. Since microwave heating is correlated with structural characteristics, the physical properties of the target(s), the response of each heated material is different. This creates a local temperature that is totally different from the bulk temperature of multiphase/multi-component systems. I have turned this serious challenge to a significant opportunity for chemical reactions in the past decade, and I would like to extend it to plastic upgrading. Plastics are unavoidable products in the modern life due to their performance at low cost, BUT most of them are only used once! In addition, the global demand for plastics could be tripled by 2050 (probably more plastics than fish in oceans by 2050). On the other hand, a majority of the used plastics are never recovered: about 90% of the plastic waste is landfilled or incinerated in the U.S. and Canada. To avoid production of unfavorable products (e.g. gases and wax), my research program is to develop and scale up a catalytic pyrolysis process wherein a microwave receptor is coupled with an appropriate catalyst. The plastic waste is a mixture of all sorts of plastics (without upstream sorting and separation of individual plastics). The purpose of this research is to transform plastic wastes to original monomers, which consequently closes the loop. In line with this long-term goal, we will investigate the synthesis of core-shell catalysts so that the microwave receptor is the core and the catalyst layer forms the shell. It is expected that this hierarchical structure under microwave heating would prevent the direct contact of plastics with the microwave receptor whereas it motivates selective production of monomers on the heated active sites of the catalyst.