METHOD OF PURIFYING SULPHUROUS-AMMONIUM WASTE WATER Russian patent published in 2016 - IPC C02F1/00 

FIELD: oil industry.

SUBSTANCE: invention relates to oil refining, petrochemical industry and is intended for separation of ammonia, hydrogen sulphide and mercaptans from sulphurous-ammonium waste water. In method of cleaning and separation of ammonia is carried out in a three-section absorber, equipped with two circulation cooled irrigation systems, located in its upper and lower parts. Liquid phase after absorption is fed into a buffer feedstock tank and further for separation into a column for extraction of sulphur-containing compounds, after which obtained vapour-gas phase - sulphur-containing compounds - is cooled and separated to obtain mercaptans and hydrogen sulphide, and obtained liquid phase is delivered for further separation into a flash tower to produce a vapour-gas phase, containing ammonia and residual sulphur-containing compounds, which is then fed for purification and separation of ammonia, and liquid phase - purified waste water, which is then cooled and part of purified waste water is taken for purification and separation of ammonia, other part - into a column for extraction of sulphur-containing compounds, and remaining part - for further biochemical treatment. Sulphurous-ammonium waste water containing mainly ammonia is fed for purification and separation of ammonia into a three-section absorber, and/or separation into a flash tower, and/or into a buffer feedstock tank for further separation in a column for extraction of sulphur-containing compounds, and sulphurous-ammonium waste water containing mainly sulphides and hydrosulphides is fed into buffer feedstock tank for further separation in column for extraction of sulphur-containing compounds or is preheated and separated in an additional flash tower, wherein formed vapour-gas phase is cooled and fed into buffer feedstock tank for further separation in column for extraction of sulphur-containing compounds.

EFFECT: invention provides efficient, reliable and uninterrupted method of purifying sulphurous-ammonium waste water, enabling extraction of ammonia, hydrogen sulphide and mercaptans from sulphurous-ammonium waste water of different composition, with both high and low concentration of dissolved substances and simultaneously obtain treated waste water of good quality, sufficient for further biochemical treatment.

1 cl, 1 dwg