| abstract |
(57) Abstract: A method and system for producing isocyanate and converting anhydrous hydrogen chloride, a by-product of isocyanate production, to chlorine gas in an electrochemical cell. This chlorine is recycled to the isocyanate step. Any unreacted anhydrous hydrogen chloride can be recycled to the electrochemical cell. The method and system can reduce the cost of isocyanate production by recirculating anhydrous hydrogen chloride and chlorine. In addition, this method and system step eliminates, or at least substantially minimizes, the problems associated with its disposal by converting anhydrous hydrogen chloride to a useful starting material for the isocyanate step. |