Leverkusen, Germany -- Bayer MaterialScience announced 17 Nov that it plans to build another chlorine recycling plant at its site in Shanghai, to ensure adequate chlorine supply for the 250 kilotonnes per annum (ktpa) toluene diisocyanate (TDI) facility it has just broken ground on.
The process for this new unit is based on the catalytic oxidation of hydrogen chloride using oxygen, which is new technology developed by Sumitomo Chemical Co. Ltd, licensed by the Japanese group to BMS.
Bayer MaterialScience recently started building the TDI unit, which will use the company's innovative gas phase phosgenation process and is scheduled to come on stream in 2010.
Sumitomo's chlorine recycling technology was awarded the prestigious Green & Sustainable Chemistry Award in Japan for being both energy-efficient and environmentally friendly, said the BMS announcement. It cuts energy consumption by more than half compared with the conventional process, the company said.
The hydrogen chloride co-produced during making isocyanates will, said BMS, be "converted very efficiently," to chlorine, which is re-used as a raw material. Sumitomo Chemical has constantly enhanced the process and verified its technical viability at working plants, the statement added.
In Shanghai, BMS said, it has just started a plant for electroysis of hydrochloric acid to supply its recently started up 350 ktpa methylene diphenyl diisocyanate (MDI) train with chlorine. This uses an energy-saving Oxygen Depolarised Cathode technology, developed by Bayer and
"By combining these two innovative technologies, we will strengthen our cost leadership in the isocyanate production. We will also be able to significantly reduce energy consumption and by that contribute to climate protection," commented Peter Vanacker (pictured), head of the Polyurethanes Business Unit of Bayer MaterialScience, in the statement.