FIELD: gas treatment. SUBSTANCE: liquid absorption method is applied for selectively removing hydrogen sulfide from gas containing both hydrogen sulfide and carbon dioxide. In the first process stage, gas 3 in tank 1 is brought into contact in at least one step with carbonate-containing alkaline solution with pH controlled during absorption period by addition of alkali such as sodium hydroxide. In the second stage, gas is burned out in combustion device 32 to convert remaining hydrogen sulfide into sulfur dioxide that is then absorbed by solution containing alkali such as sodium hydroxide in scrubbing apparatus 36. Combining hydrogen sulfide absorption with carbonate-containing solution in the first stage and burning remaining hydrogen sulfide and absorption of resulting sulfur dioxide by alkali solution in the second stage gives rise to complete separation of hydrogen sulfide with high selectivity. EFFECT: enhanced process and economical efficiency. 13 cl, 2 dwg, 1 ex
