Hydrogen chloride purificn. from chlorine and organic cpds. - for dichloro ethane mfr. by passing mixt. with ethylene over active carbon

摘要

In the purificn. of HCl obtd. from the chlorination of org. cpds. and contaminated with Cl2, for the prodn. of CH2Cl. CH2Cl by the oxychlorination process, the impure HCl is passed over active C in conjunction with C2H4 in an amt. corresp. to its Cl2 content or pref. up to 10 times this molar amt. The active C should have a large surface area, pref. of >250 m2/g, and the moist HCl pref. is preheated to 30-180, pref. 120-140 degrees C. The process avoids various costly operations used previously. In an example, HCl from the chlorination of C6H6 contg. 0.5 (vol.)% Cl2, 0.7% C6H6, 0.01% chlorobenzene and 20 ppm H2O, was purified by mixing with C2H4 and passing over an active C filter at 130 degrees C, which removed Cl2 and benzene cpds. Traces of C6H6 were present after 24 hrs. and the filter was then regenerated with steam and dried with hot N2 before re-use.