Plastic Waste Upgrading by Coupling Microwave Heating with Catalytic Pyrolysis

我提出的研究重点是循环经济，其中过程电气化与催化热解相结合，以解决一个新兴的和严重的环境问题：塑料废物。由于传统和易于处理的资源的枯竭以及日益严格的环境法规，循环经济是价值链线性经济的一个不错的替代方案。通过这样做，加拿大人将大大受益于废物的更好利用（和增值）。它将改善加拿大的环境表现，为其工业提供新的收入来源，并使其工业更具竞争力。为了利用和增值废物，由于交叉污染和废物分类过程的限制，回收并不总是在技术和经济上可行的。

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.