CS207296B1 - Method of cleaning the hydrochloric acid - Google Patents

Description

THE CZECHOSLOVAK SOCIALISTIC DESCRIPTION FOUND 207296 R E PU B LI (1β) A CERTIFICATE OF CERTIFICATE (11) (Bl) v ***! i (22) Registered 14 03 80 (21) (PV 1758-80) 1 (51) Int. Cl.3 C 01 B 7/07 OFFICE AND DISCOVERY OFFICE (40) Published 15 09 80 (45) Published 01 11 82

Author of the invention ŠAULI VLADIMÍR ing., HENKE HEŘMAN ing., BERÁNEK IVAN ing.,

SLÁDEK JAN, ÚSTÍ NAD LABEM aGALLERT MILOSLAV, CHABAŘOVICE (54)

BACKGROUND OF THE INVENTION The present invention relates to a process for the purification of hydrochloric acid resulting from the uptake of hydrogen chloride from chlorinated hydrocarbons into water and containing hydrocarbons of the formula CnH2n + 2 and / or CnH2n wherein n = 1, 2,3 and / or their monochloro derivatives and / or dichloro derivatives of hydrocarbons. CnH2n + 2a / or CnH2n, where n = 1, 2. In the preparation of hydrocarbon chlorinates, hydrogen chloride is formed as a side reaction product, which is separated from the reaction mixture either directly or prior to treatment with water to form hydrochloric acid. However, the hydrochloric acid thus obtained usually contains small amounts of starting hydrocarbons, in the case of mono- or dichloro-derivatives thereof. The content of these components is defective in hydrochloric acid and is often the cause of the unusability of this acid, which is a difficult waste. Chlorinated hydrocarbons contained in the hydrochloric acid interfere with the technical rubber known to be present in wt. concentrations higher than 0.005% in acid, it is then no longer possible to store this acid in containers and transport it in cisterns lined with technical rubber.

Until now, the recovery of hydrochloric acid free of hydrochloric hydrocarbons has been solved by the perfect separation of these substances from hydrogen chloride prior to absorption. However, this process is also highly demanding in terms of energy, since it assumes the rectification of contaminated hydrogen chloride with a high degree of separation of impurities. Moreover, it is usually not possible to prevent the formation of chloro-derivatives in the actual absorption of hydrochloric acid water. There is also described the process of removing undesired chlorinates contained in hydrochloric acid, by avoiding acid-free, obtaining a concentrate of chlorinates in hydrochloric acid, from which the largest part of the chlorinates is separated as a separate liquid phase after absorption in water. for balancing in concentrated salt acid and heat energy consumption.

These disadvantages can be eliminated by the process of purifying hydrochloric acid formed by the uptake of hydrogen chloride from the chlorination of hydrocarbons into water and containing hydrocarbons of the formula CnH2n + 2 and / or C 'H2n, where n = 1,2,3 and / or their monochloride derivatives and / or dichlorohydrocarbons having the formula C n H 2n + 2 and / or C n H 2n wherein n = 1.2 according to the invention. This method consists in blowing out the hydrochloric acid solution! air at 0.01 to 1 m 3 (based on the normal condition) per kg of hydrochloric acid at temperatures from -20 to + 50 ° C.

Claims (1)

The method of purifying hydrochloric acid from undesirable hydrocarbons and their chlorinates can be most conveniently carried out in countercurrent columns where the undesired hydrochloric acid is dispensed into the top of the column and the propelling air is fed to the bottom of the column. Subsequently, the hydrochloric acid is removed from the bottom of the column by a reduced hydrocarbon content, respectively. their chlorinated derivatives. An advantage of the hydrochloric acid purification process according to the invention is the very low cost of purifying the acid, consisting of low energy consumption and relatively low equipment requirements, since conventional construction materials are fully satisfactory in the process of the invention. EXAMPLE 1 To a continuously operating six-tier column, the first tray (counted from above) is supplied with 18 DEG C. hydrochloric acid in an amount of 2000 kg / h and a weight of about 1 kg. 33% HCl containing 0.038% isopropyl chloride. 150 m3 / h of air is fed to the bottom of the sixth floor at -15 ° C. Thereafter, hydrochloric acid of 32.6% by weight, containing 0.0003% isopropyl chloride, is withdrawn from the base of the six-column column. SUBJECT OF THE PRINCIPLE Purification of hydrochloric acid resulting from the uptake of hydrogen chloride from chlorination of hydrocarbons and containing hydrocarbons of the formula CnH2n + 2 and / or CnH2n, where n - 1, 2, 3 and / or their monochloro derivatives and / or dichloro derivatives. (calculated from above) the salt acid supplied by wt. the concentration was 33.6% and the temperature was 22 ° C at 1900 kg / h containing 0.0621% isopropyl chloride, 0.0042% allyl chloride and 0.0020% propylene. At the bottom of the column, the sixth floor is supplied with air of 170 m 3 / hp at a temperature of 31 ° C. The hydrochloric acid is then removed from the bottom of the six-storey column by weight. a concentration of 32.8% HCl containing 0.0006% isopropyl chloride, 0.0003% allyl chloride and a propylene concentration of less than 0.0001%. EXAMPLE 3 To a continuously operating six-tier column, the first tray (counted from above) is supplied with hydrochloric acid at 25 DEG C. in an amount of 0.980 kg / h by weight. a concentration of 33.2% HCl containing 0.0324% ethyl chloride, 0.0037% dichloro. ethane and 0.0042% vinyl chloride. 0.13 m 3 / h at 17 ° C is fed to the column bottom. The hydrochloric acid is removed from the base of the six-tier column by weight. a concentration of 32.3% HCl containing 0.001% dichloroethane and with a content of other constituents below 0.0001%. OF THE INVENTION The hydrocarbons of the formula CnH2n + 2, and / or CnH2n, wherein n = 1, 2, characterized in that the acidic acid is purged with air in an amount of 0.01 to 1 m 3 per 1 kg of hydrochloric acid at temperatures of range -E0 to + 50 ° C.