Bayer readies HCl process

Bayer will feature new technology for hydrochloric acid electrolysis at plants it is building in Shanghai for the polyurethane raw materials methylene diphenyl diisocyanate and toluene diisocyanate. In the so-called oxygen-depleting cathode technology, developed by Bayer and partners, HCl generated as a by-product of isocyanate production is separated via electrolysis into chlorine and hydrogen, with oxygen as a co-reactant. The chlorine is then reused for isocyanate production. The electrode that depletes the oxygen functions as a cathode, hence the technology's name.