| 摘要 |
1,266,676. Purification of 1,2-dichloroethane. KNAPSACK A.G. 7 April, 1970 [9 April, 1969], No. 16345/70. Heading C2C. 1,2-Dichloroethane recovered from the incomplete thermal cracking of 1,2-dichloroethane to vinyl chloride and contaminated with low boilers boiling below 83.7‹ C. and high boilers boiling above 83.7‹ C. is purified by reaction with gaseous chlorine in the presence of ferric chloride at 30-85‹ C. to convert low boilers to high boilers, and distillation of 1,2-dichloroethane from the high boilers. The process may be effected by (a) chlorinating contaminated 1,2- dichloroethane simultaneously with the chlorination of ethylene to form 1,2-dichloroethane, and distilling off the 1,2-dichloroethane, or (b) distilling the contaminated 1,2-dichloroethane in a low boiler distillation column, continuously removing a 1,2-dichloroethane-low boiler mixture from the head of the column, chlorinating the mixture, recycling the reaction mixture to the low boiler distillation column, and either (1) removing a 1,2-dichloroethane high boiler mixture from the base of the column and passing it to a high boiler distillation column, or (11) continuously removing 1,2-dichloroethane at a position below the column head and removing high boilers from the column base. A single column may serve as both a low boiler distillation column and a high boiler distillation column. |
