| abstract |
Isocyanate in the present inventionn n n (a) reacting chlorine with carbon monoxide to form phosgene,n n n (b) reacting the phosgene with the organic amine to form isocyanate with hydrogen chloride,n n n (c) separating the isocyanate and hydrogen chloride,n n n (d) optionally purifying hydrogen chloride,n n n (e) preparing an aqueous solution of hydrogen chloride,n n n (f) optionally purifying an aqueous solution of hydrogen chloride,n n n (g) electrochemically oxidizing the aqueous hydrogen chloride solution to form chlorine,n n n (h) at least a portion of the chlorine produced in (g) is circulated to (a). |