Method for making polycarbonate

摘要

Producing polycarbonate comprises: (a) preparing phosgene; (b) reacting the phosgene formed in (a) with at least one bisphenol to form a polycarbonate and an alkali chloride containing reaction wastewater solution; (c) separating and reprocessing the polycarbonate formed in (b); (e) carrying out osmotic membrane distillation of at least a portion of the remaining alkali chloride containing solution obtained from (c); and (f) electrochemically oxidizing at least a portion of the alkali chloride containing solution obtained from (e) to form chlorine, alkaline lye and optionally hydrogen. Producing polycarbonate comprises: (a) preparing phosgene by reacting chlorine with carbon monoxide; (b) reacting the phosgene formed in (a) with at least one bisphenol in presence of an aqueous alkali containing base to form a polycarbonate and an alkali chloride containing reaction wastewater solution; (c) separating and reprocessing the polycarbonate formed in (b); (e) carrying out osmotic membrane distillation of at least a portion of the remaining alkali chloride containing solution obtained from (c); and (f) electrochemically oxidizing at least a portion of the alkali chloride containing solution obtained from (e) to form chlorine, alkaline lye and optionally hydrogen.