Asahi Kasei will significantly downsize its petrochemical business, withdrawing from the production of polyolefins and styrene at its Mizushima, Japan, site by around 2030.
The company will also stop making acrylonitrile and polycarbonate diol at the site and will shift output to existing facilities in South Korea and China. In addition, Asahi Kasei says it will limit its stake in a planned olefins joint venture with Mitsui Chemicals and Mitsubishi Chemical Group to 10%.
Japan’s petrochemical sector has been hit hard by intensifying competition in East Asia—once a key export market—and by stagnant domestic demand driven by demographic decline.
“Japan’s ethylene crackers have operated below the break-even utilization rate of 90% for 44 consecutive months and most recently remain in the 70% range,” Asahi Kasei president Koshiro Kudo said at a press conference on May 12. “We have set a 4-year transition period to give downstream customers sufficient time to build alternative supply chains before production is halted in 2030. Production capacity for products such as polyolefins that will be suspended or reorganized far exceeds domestic demand, including that of other producers, and the restructuring will help improve industry-wide utilization rates.”
Asahi Kasei’s styrene production capacity stands at 370,000 metric tons (t) per year. According to the Japan Petrochemical Industry Association, domestic capacity totaled 1.61 million t as of December 2024, while demand was only 1.07 million t—highlighting substantial overcapacity. Polyolefins face a supply-demand gap exceeding 1 million t.
For acrylonitrile, the company will shut down its 200,000 t line at Mizushima around 2030 and shift production to Tongsuh Petrochemical, a joint venture in South Korea. Polycarbonate diol production at Mizushima will also cease around the same time, and manufacture will continue at Asahi Kasei’s site in Nantong, China.
Asahi Kasei, Mitsui Chemicals, and Mitsubishi Chemical Group have already agreed to integrate their two ethylene crackers in western Japan under a three-way joint venture. The plan calls for shutting down the Asahi Kasei Mitsubishi Chemical Ethylene Corp. (AMEC) cracker in Mizushima in fiscal 2030 and consolidating ethylene output at Mitsui Chemicals’ plant in Osaka, Japan.
At the press event, Kudo added that although Asahi Kasei’s equity share in the joint venture will be small, the company sees an opportunity to contribute to the project’s decarbonization efforts. He noted that Asahi Kasei’s Revolefin technology—which enables one‑stop production of olefins and aromatics from bioethanol—is now being considered for adoption at the Osaka ethylene center.
Asahi Kasei’s petrochemical business accounted for 12% of sales in fiscal 2025, and the company expects the share to fall to only a few percent by the end of the decade. Asahi Kasei derives most of its revenue from pharmaceuticals, medical devices, residential housing construction, and electronics materials.
The firm announced last May (PDF) that it would cease production of methyl methacrylate, cyclohexyl methacrylate, acrylic resin, styrene-butadiene latex, and acetonitrile at its site in Kawasaki, Japan.
