Asahi Kasei and Microwave Chemical have announced the launch of a joint demonstration project for the recycling of PA66 using microwave technology.

Source: SustainablePlastics

According to the partners, the process allows the depolymerisation of PA66 directly into the monomers hexamethylenediamine (HMD) and adipic acid (ADA). It is a high-yield process, say the companies that, moreover, requires relatively little energy.

Asahi Kasei produces fossil fuel–derived HMD and ADA as intermediates to manufacture Leona PA66, an engineering plastic characterised by outstanding heat resistance and rigidity. PA66 is used in various applications, including plastic parts for automotive and electronic products, and yarn for airbag fabric, and its demand is expected to increase worldwide.

Seeking to reduce the level of  greenhouse gas (GHG) emissions associated with the production of fossil-based raw materials, the company is now exploring the use of Microwave Chemical’s PlaWave recycling technology platform as a potential source of a more circular supply of monomers. It is also conducting trials for the commercialisation of PA66 made using biomass-derived intermediates.

In the present project, PA66 manufacturing scraps and post-use waste material from airbags and automobile parts are used to demonstrate the depolymerisation process.

Together, the two companies aim to commercialise a lower-carbon manufacturing process for PA66 based on intermediates derived from the PlaWave depolymerisation process. Laboratory-scale studies have confirmed the high-yield depolymerisation of PA66 using microwaves, as well as the principle of the separation and purification process after depolymerisation. The next step is the installation by the end of fiscal 2023 of bench-scale equipment at Microwave Chemical’s Osaka Factory, followed by a small-scale demonstration trial using this equipment in fiscal 2024 to collect basic process data for commercialisation. A further reduction in GHG emissions could also be achieved through the use of renewable energy to power the process.

Whether or not the companies will move forward towards commercialisation will be decided by fiscal 2025, following a detailed analysis of the results of the small-scale demonstration trial. At the same time, a business model will be developed that brings together the entire PA66 chemical recycling value chain with a view to advancing circularity for PA66.

Microwave Chemical is also working to increase the scale of its equipment and to broaden the scope of application of its PlaWave platform. In the future, the company envisions using the technology to chemically recycle PMMA, automotive shredder residue (ASR), plastic containers and packaging, flexible polyurethane foam, and more.