METHOD OF PURIFYING INDUSTRIAL SEWAGE FROM SULFIDE SULFUR AND AMMONIUM NITROGEN Russian patent published in 2001 - IPC

FIELD: oil refining industry, more particularly purification of industrial condensate. SUBSTANCE: condensate is admitted into absorption and stripping column. Hydrogen sulfide-enriched water vapors are reacted with circulating cold condensate in layer of packing. Hydrogen sulfide is withdrawn from column top. Ammonia enriched-stillage residue is admitted into rectification column which is sprayed with circulating current of liquid on upper trays. Stillage product which is purified condensate is partially recycled into absorption and stripping column. Upper product of rectification column includes mixture of ammonia, residual hydrogen sulfide and steam and is cooled in packing scrubber. The ammonium hydrosulfide solution is admitted into absorption and stripping column. Pure ammonia is withdrawn from scrubber top. EFFECT: continuous operation of column without deposits of ammonium hydrosulfide salt in columns and pipelines. 14 cl, 3 ex, 2 tbl