ROLES OF REACTOR WALL AND SOLVENTS IN THE CARBON DEPOSITION FROM ETHYLENE DICHLORIDE UNDER HEAT-EXCHANGER CONDITIONS OF ITS COMMERCIAL PYROLYSIS

摘要

Carbon deposition on the shell wall of heat-exchanger tube in the commercial EDC pyrolysis process is a practical problem, which lowers the productivity and increases the cost and labors because of lowered heat-transfer and decoking maintenance The deposited carbon has been reproduced by heating EDC under the same pressure to that of the heat-exchanger of commercial process and its origin has been ascribed to the slow but definite pyrolysis of EDC and its reactive impurities contained in the commercial feed. The shell wall which is corroded by HC1 produced through the pyrolysis of EDC was found also influential on the carbon deposition. In the present study, roles of vessel wall and solvents present together with EDC were studied to find ways to suppress the carbon deposition under the heat-exchanger conditions applied commercially in the vinyl chloride manufacture from EDC.