Asahi Kasei and Microwave Chemical launched a joint demonstration project in April 2023 with the objective of commercializing a chemical recycling process for polyamide (PA) 66 using microwave technology. The process utilizes microwaves to depolymerize PA66 and directly obtain the monomers hexamethylenediamine (HMD) and adipic acid (ADA). The monomers can then be used to manufacture new PA66. The companies anticipate high yields with low energy consumption. In the demonstration, scraps from manufacturing and post-use waste material of PA66 for airbags and automobile parts are depolymerized.
Asahi Kasei produces fossil fuel–derived HMD and ADA as intermediates to manufacture Leona PA66. The rigid, heat-resistant material is used in various applications, including plastic parts for automotive and electronic products, and yarn for airbag fabric. Global demand is expected to increase, even as industry faces pressure to reduce greenhouse gas (GHG) emissions from chemical products derived from fossil fuels.
Image courtesy of Asahi Kasei
|Chemical recycling of PA66 using microwave-based technology furthers the circular economy.|
Microwave Chemical is promoting carbon neutrality in the industrial sector by focusing on process development using microwaves, which can directly and selectively heat target substances with high energy efficiency. For chemical recycling, Microwave Chemical is advancing its proprietary PlaWave technology platform for decomposing plastic using microwaves.
By combining Asahi Kasei's experience in manufacturing HMD and ADA for more than a half century with Microwave Chemical's industrialization of microwave technology, the two companies aim to commercialize a manufacturing process for PA66 that can reduce GHG emissions. Laboratory-scale studies that began in fiscal 2021 have confirmed the high-yield depolymerization of PA66 using microwaves, as well as the principle of the separation and purification process after depolymerization. Bench-scale equipment will now be assembled at Microwave Chemical’s Osaka factory by the end of fiscal 2023, and a small-scale demonstration trial using this equipment will be performed in fiscal 2024 to collect basic process data for commercialization.
By verifying the process from depolymerization to separation and purification in an integrated manner, this demonstration project aims to enable resource circulation of PA66 for further reduction of GHG emissions. Based on the results of the small-scale demonstration trial, a decision on potential commercialization will be made by fiscal 2025, said the two companies. Concurrently with the demonstration trial, a business model will be drafted that seeks to involve the entire value chain in the chemical recycling of PA66. The objective is to achieve a circular economy in concert with stakeholders in the PA66 value chain.