PROCESS FOR PREPARING METHANIC CHLOROHYDROCARBONS Russian patent published in 1999 - IPC

FIELD: chemical technology, more particularly manufacture of fluorochlorohydrocarbons. SUBSTANCE: in the claimed process for preparing methanic chlorohydrocarbons, at least some portion of hydrogen chloride, before being treated with methanol, is subjected to isothermal absorption with 27-32% hydrochloric acid to obtain 35-45% hydrochloric acid which is directed for purification of methyl chloride to remove dimethyl ether which results from treating hydrogen chloride with methanol, 35-45% hydrochloric acid thus formed is further treated with methanol, and hydrogen chloride containing abgases resulting from preparation of hydrochloric acid are subjected to adiabatic absorption with azeotropic hydrochloric acid to obtain 27-32% hydrochloric acid which is then subjected to isothermal absorption. Vapor- gas mixture formed in adiabatic absorption stage is subjected to absorption with precooled methanol, and the absorbate thus formed is further directed to stage where hydrogen chloride is treated with methanol. Said stage is carried out in boiling azeotropic hydrocarbon acid. The azeotropic acid thus formed is subjected to purification to remove methanol and subsequently directed to adiabatic absorption stage, and after purification, method chloride, before being chlorinated, is condensed. EFFECT: smaller amounts of sulfuric acid, formation of weak hydrochloric acid free from admixtures, improved ecological parameters and greater economic production efficiency. 100 cl, 13 dwg