METHOD FOR PURIFICATION OF AN AMMONIA-CONTAINING GAS AND PRODUCTION OF ANHYDROUS LIQUID AMMONIA Russian patent published in 2021 - IPC C01C1/02 C01C1/10 B01D53/14 B01D3/26 

FIELD: chemistry.

SUBSTANCE: invention relates to the chemical industry and can be used to produce liquid technical ammonia from an ammonia-containing gas containing impurities of acid gases, mercaptans, and water vapours in addition to ammonia. The method for purification of an ammonia-containing gas and production of anhydrous liquid ammonia includes a stage of purifying the ammonia-containing gas and a stage of producing anhydrous liquid ammonia. At the stage of purifying the ammonia-containing gas, the ammonia-containing gas interacts with water in an absorber. The part of ammonia water collected on a blind collector plate of the absorber is cooled and supplied to the absorber as reflux. On the signal from the flow analyser installed on the ammonia water discharge pipeline and on the signal from the temperature sensor installed in the upper part of the absorber, the flow rate of water and ammonia water supplied to the absorber is changed. At the stage of producing anhydrous liquid ammonia, ammonia water with a concentration of 15 to 30 wt.% obtained at the stage of purifying is supplied to the middle part of the distillation column and is therein divided into ammonia-enriched vapours and water at a pressure of 1.4 to 2.5 MPa. The ammonia-enriched vapours are removed from the distillation column and condensed. A part of the produced anhydrous liquid ammonia is supplied into the distillation column as reflux and for throttling followed by supplying the cooled gaseous ammonia into the absorber.

EFFECT: invention provides a possibility to increase the efficiency of absorption of polluting substances, such as hydrogen sulphide, carbon dioxide, mercaptans, and the output of anhydrous liquid ammonia.

1 cl, 1 dwg, 4 tbl