METHOD FOR OBTAINING MONOCHLORACETIC ACID Russian patent published in 2018 - IPC C07C51/363 C07C51/43 C07C51/44 C07C53/16 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for the chlorination of acetic acid with the formation of monochloroacetic acid, comprising the following stages: a) the interaction of acetic acid with chlorine using acetic anhydride and / or acetylchloride as a catalyst with the formation of the liquid phase and the gas phase, the liquid phase contains at least monochloroacetic acid, acid chlorides, acid anhydrides and optionally unreacted acetic acid, and the gas phase contains HCl, acetic acid, monochloroacetic acid and acid chlorides, b) steaming said liquid phase at a temperature of 120 to 180 °C, and a pressure of from 1 to 7 bar abs., using gaseous HCl to form a stream of gaseous HCl containing acetic acid, acid chlorides, and optionally acid anhydrides and monochloroacetic acid, and a liquid stream containing monochloroacetic acid and dichloroacetic acid; c) cooling the stream of gaseous HCl containing acetic acid, acid chlorides, acid anhydrides and optionally monochloroacetic acid, to a temperature of from 10 to 60 °C (preferably about 35 °C), and d) loading the cooled HCl gas into the acetic acid absorber as an absorbent that absorbs acetic acid, acid chlorides and optionally monochloroacetic acid, to form a stream containing acetic acid and acid chlorides.

EFFECT: method provides efficient dechlorination and is sound from a technical, environmental and economic point of view.

13 cl, 1 dwg