As part of a project of Japan’s New Energy and Industrial Technology Development Organization (NEDO), Asahi Kasei Corp. (Tokyo, Japan; www.asahi-kasei.co.jp) verified a newly developed process for diphenyl carbonate (DPC), a monomer used to produce polycarbonate (PC), which is used to make parts for vehicles, home appliances, etc., via dialkyl carbonate (DRC), at its Mizushima Works (urashiki, Okayama, Japan). The stability and operability of the process was confirmed through over 1,000 hours of continuous operation. Compared to the conventional process, the new process successfully reduces energy consumption and CO2 emission while using CO2 as a safe feedstock.
Asahi Kasei will continue to verify the economy and energy efficiency of the new process, and work toward its further optimization as a highly energy-efficient process that utilizes CO2.
The project facilitated production of 1,000 metric tons per year (m.t./yr) of DPC over two years in a site located at Asahi Kasei’s Mizushima Works (Kurashiki, Okayama, Japan).
As part of a NEDO project, in 2015 Asahi Kasei began construction of a validation plant at its Mizushima Works to verify its newly developed process to produce DPC via DRC (the DRC process for DPC) to overcome these issues. Stability and operability as an industrial process was also confirmed through over 1,000 hours of continuous operation. Asahi Kasei has successfully established the non-phosgene process using CO2 as a safe feedstock, enabling not only reduced energy consumption but also reduced CO2 emission.
Asahi Kasei will continue to verify the economy and energy efficiency of the new process, and work toward its further optimization. Specifically, the company aims to achieve commercialization of the new highly energy-efficient process using CO2 with reduced energy consumption through improved yield, and to establish technology for stable production by optimizing operating conditions and equipment. Validation of the new process will strengthen the licensing business Asahi Kasei established with its previously developed non-phosgene process for PC, which is used around the world including in China, Korea, Taiwan, Russia, and Saudi Arabia.
The DRC process for DPC utilizes technology that was developed by Asahi Kasei with the support of a NEDO project, using catalysts to obtain DRC from CO2 and alcohol, and then obtain DPC from DRC and phenol. We have validated the feasibility of the DRC process for DPC through continuous operation to assess catalyst cycling and catalytic performance in both the DRC step, which produces DRC from CO2 and alcohol, and the DPC step, which produces DPC from DRC and phenol, as well as reactor performance and the system to recycle unreacted feedstocks.