Recycling chlorine in Caojing

Chlorine is an essential raw material for production of methyl diphenyl diisocyanate (MDI), a chemical used to manufacture polyurethane foam for a variety of products and industrial applications. Chlorine requires an electrolysis process, which requires a large amount of electricity and energy, to convert the chlorine into hydrogen chloride (HCL) gas used in the production process.

In January 2018, Huntsman installed a 120,000-ton chlorine plant at it manufacturing facility in Caojing, China, for MDI production. The plant features an innovative proprietary HCL recycling process in which HCL gas is converted directly back into chlorine, reducing the amount of energy needed in the production process and eliminating 268,000 tons of caustic soda typically created as a byproduct. By converting the HCL back into chlorine to be used as a raw material, the process also substantially reduces CO₂ associated with production.