METHOD OF EXTRACTING AMMONIA AND APPARATUS FOR REALISING SAID METHOD Russian patent published in 2012 - IPC C02F9/00 C02F101/16 

FIELD: chemistry.

SUBSTANCE: CO₂ and H₂S are extracted from ammonia-containing waste water in form of a gas having low moisture content using columns for distilling CO₂ and H₂S, in which pressure higher than atmospheric pressure is maintained. CO₂ and H₂S are extracted from the top part of the column and a solution containing ammonia is extracted from the bottom part of the column. The solution containing ammonia is fed into a column for distilling ammonia, which is kept at pressure lower than pressure in said column for distilling CO₂ and H₂S. Ammonia-rich gas, containing a small amount of CO₂ and H₂S, is extracted from the top part of the column, and water, which is used as process water, is extracted from the bottom part of the column for distilling ammonia. Ammonia-rich gas is fed into a washing column which is kept at pressure lower than pressure in the column for distilling ammonia. Waste water containing a sodium compound is extracted from the bottom part of the washing column while a gas rich in ammonia and not containing H₂S is extracted from the top part of the washing column. Said washing column comprises an upper washing column for washing with water and a lower washing column for washing with NaOH, said columns being connected to each other.

EFFECT: invention enables to extract ammonia from waste water to obtain a mixture of ammonia and water vapour, process water and gas rich in CO₂ and H₂S, which is used to produce sulphuric acid.

5 cl, 1 tbl, 4 dwg, 1 ex