PROCESS FOR PRODUCING AMMONIUM THIOSULPHATE

摘要

A process is provided for removing hydrogen sulphide and ammonia out of a ga s (12), such as sour water stripper gas. The hydrogen sulfide and ammonia- containing gas is fed into a first reactor (38) where only a portion of the hydrogen sulfide and ammonia are sorbed out of the gas into an ammonium sulfite and ammonium bisulfite-containing scrub solution (40), where the sorbed hydrogen sulfide and sorbed ammonia react with the sulfite values within the scrub solution to form ammonium thiofulfate product. The residual , unsorbed hydrogen sulfide and unsorbed ammonia from the gas are fed into a water scrubber (74), where water, ammonia and hydrogen sulfide react to form ammonium bisulfide product and a gas containing residual, unreacted hydrogen sulfide (78). This residual, unreacted hydrogen sulfide may be combusted int o sulfur dioxide. This sulfur dioxide (or sulfur dioxide from another source) (84) is mixed with the scrub solution (58) in a second reactor (82) where it reacts with the ammonia therein to provide the ammonium sulfite and ammonium bisulfite necessary for the production of ammonium thiosulfate product.