Japanese firms Mitsui Chemicals and Microwave Chemical Co. have launched an initiative aimed at commercializing the use of microwave technology in the chemical recycling of plastic waste. The project involves directly producing raw monomers from plastics that have conventionally been tricky to recycle, including automotive shredder residue (ASR) – a mixture of principally polypropylene-based plastics – and thermosetting sheet molding compound (SMC), which is used in bathtubs and vehicle parts.
Since entering into a strategic partnership in 2017 to promote joint development of next-generation chemical process technologies, Mitsui Chemicals and Microwave Chemical have built up a solid relationship, including through partial equity investment. The two companies together are looking at leveraging microwave technology for a variety of chemical processes.
This new initiative is an attempt to commercialize a chemical recycling technique that uses the PlaWave microwave-based plastic degradation technology developed by Microwave Chemical to directly break down ASR and SMC products into raw monomers. As it eliminates an intermediate step, direct monomerization is a more efficient means of recycling plastic waste into plastic than the conventional approach, which involves turning the waste into oil before monomerization. The technique also promises to reduce CO2 emissions through the use of electricity generated from renewable energy to power the decomposition process.
With initial deliberations having yielded positive results, the project will proceed to verification using Microwave Chemical’s bench-scale equipment before the end of fiscal 2021. A move to full implementation will then be considered with the objective of promptly commencing demonstration tests.