Conventional wisdom has long been that the inferiority of recycled material compared with virgin product is caused by chemical or physical deterioration taking place in the material recycling process. More specifically, the understanding is that polymer chains are broken by UV rays or heat during processing, or that physical properties deteriorate on account of contamination.
Professor Shigeru Yao of Fukuoka University has verified that physical deterioration is the cause – finding that this phenomenon occurs when processing pellet-form recycled materials, resulting in internal structural changes. This then led to the discovery that recycled material can exhibit performance akin to that of virgin product depending on the conditions, such as by having the plastic kept in a molten state for a long period of time before rapidly cooling it. Technological development efforts are now moving forward between Fukuoka University and a number of companies that make up the plastic value chain, including Asahi Kasei Corp. (TYO:3407), Kao Corp. (TYO:4452), DIC Corp. (TYO:4631), Toppan Printing Co. Ltd. (TYO:7911) and Mitsubishi Electric Corp. (TYO:6503).
Then there is the matter of contamination, with substances like food residue, colorants and inks all potentially posing high barriers to the successful material recycling of packaging. For these purposes, chemical recycling methods – such as chemical recycling to monomer (CRM) or oil conversion – are considered to be the ultimate technology given the usefulness of obtaining chemical raw materials to be obtained without any quality degradation.
Mitsubishi Chemical Corp. and Eneos Corp. are currently in talks about integrating their respective petrochemical operations in view of implementing chemical recycling. Sekisui Chemical Co. Ltd. (TYO:4204) and Sumitomo Chemical Co. Ltd. (TYO:4005), meanwhile, are working on new technology for obtaining polyolefins from combustible household waste. This project will see Sekisui Chemical decompose the waste into carbon monoxide and hydrogen by way of gasification melting before converting this into ethanol with microorganisms from U.S. biotech company LanzaTech Inc. Sumitomo Chemical will then use a dehydration reaction to purify the ethanol into ethylene and produce polyolefins, making for a process where there is no need to separate out any raw material waste. Aims are to get the project ready for commercialization by 2025.
Elsewhere, there are efforts being made for the chemical recycling of polystyrene trays and other such monomaterial containers. Toyo Styrene Co. Ltd., PS Japan Corp. and DIC are working here with numerous domestic container manufacturers for a project that will see demonstration equipment set up for 2021–2022.
Then for the recycling of polyethylene terephthalate (PET), the increasing amount of activity taking place among beverage makers has seen Suntory Holdings Ltd. and other major suppliers establish a JV to utilize the technology of U.S. biochemical venture company Anellotech Inc. The JV is being targeted for launch with a Japanese plant in 2027. And in a separate effort, Mitsubishi Chemical plans to launch a joint project with Kirin Holdings Co. Ltd. (TYO:2503), with aims here being to achieve practical application of PET chemical recycling that same year.
Part 6 in this series coming soon.