METHOD OF CLEANING PROCESS CONDENSATES FROM HYDROGEN SULPHIDE AND AMMONIA Russian patent published in 2019 - IPC C02F1/04 

FIELD: water and air purification technology.

SUBSTANCE: invention relates to a method of cleaning process condensates from hydrogen sulphide and ammonia. Method of treating waste water from hydrogen sulphide and ammonia includes: feeding untreated effluents as power to a system of columns equipped with mass exchange devices, the system of columns is made in the form of two series-connected columns: columns for extracting hydrogen sulphide and a column for producing purified waste water, with removal of purified waste water from the system, gaseous hydrogen sulphide and ammonia gas mixture with residual hydrogen sulphide and water, returning part of treated waste water to upper part of hydrogen sulphide extraction column, feeding ammonia gas mixture with residual hydrogen sulphide and water for further purification into ammonia purification absorber with ammonia discharge lines from above ammonia purification absorber and saturated absorbent from below ammonia purification absorber, additional purification of ammonia gas mixture with residual hydrogen sulphide and water is carried out in an absorber of ammonia purification by an absorbent. Gas mixture of ammonia with residual hydrogen sulphide and water is cooled in a condenser of vapors of a column for producing purified waste water and then fed into an ammonia purification absorber under a nozzle layer. Said absorbent is obtained by mixing ammonia vapors leaving the ammonia purification absorber with treated waste water from the treated waste water stream from the purified waste water production column. Said absorbent after mixing is cooled in heat exchanger, where partial dissolution of ammonia takes place in water flow with formation of cold flow of absorbent (ammonium water), and after cooling is supplied into absorbent tank. Steam-liquid flow is separated in vessel into gaseous ammonia and liquid absorbent (ammonium water). Saturated absorbent stream is discharged from the ammonia purification absorber separating said stream of saturated absorbent into two portions and feeding one portion of the stream to the upper portion of the purified waste water production column, and the second part is used as a recycle stream into the hydrogen sulphide recovery column below the input of raw waste water.

EFFECT: high degree of purification of process condensates and waste components, as well as reduced operating costs for the process.

4 cl, 1 dwg, 1 tbl