METHOD OF TREATING AN ACID GAS STREAM AND AN APPARATUS THEREFOR

摘要

The present invention provides a method of treating an acid gas stream (820) comprising H2S and CO2 to provide an aqueous ammonium sulphate stream (190) and an apparatus (1) therefor, the method comprising at least the steps of : (a) passing an acid gas stream (820) comprising H2S and CO2 to an incinerator (850) to oxidise H2S to SO2 to provide an incinerator flue gas stream (860) comprising SO2 and CO2; (b) passing the incinerator flue gas stream (860) to a sulphuric acid unit (900) to produce H2SO4 from SO2 in the flue gas stream (860) to provide an aqueous sulphuric acid stream (910) and a sulphuric acid unit off-gas stream (920) comprising CO2; and (c) passing at least a part of the aqueous sulphuric acid stream (910) to an ammonia scrubber (150) which is provided with a first off-gas stream (120) which comprises NH3, H2S and CO2 to separate NH3 to provide a scrubber off-gas stream (180) comprising H2S and CO2 and an aqueous ammonium sulphate stream (190).