FIELD: gas treatment. SUBSTANCE: invention relates to cleaning gas to remove sulfur compounds with liquid absorbents for application in gas and petroleum processing, chemical, and other areas to selectively remove hydrogen sulfide from low-sulfur hydrocarbon and effluent gases and also for cleaning small volumes of high-sulfur gases. Treatment of gas is accomplished in absorption apparatus by bringing gas in contact with aqueous solution containing ethanolaminomethanol and/or diethanolaminomethanol which are prepared in absorption apparatus by interaction of mono- and/or diethanolamine with formaldehyde directly in the gas treatment process. Formaldehyde is advantageously used in the form of 30-40% aqueous solution (formalin) which is fed into absorption apparatus continuously to provide molar ratio of formaldehyde to hydrogen sulfide to be neutralized equal to 3: 1. Mono- and diethanolamine are advantageously used in the form of 50-98% aqueous solution that is periodically or continuously introduced into absorption apparatus to provide molar ratio of ethanolamine to hydrogen sulfide to be neutralized no less than 0.7:1. Preferred gas treatment temperature is 15 to 60 C. EFFECT: increased gas cleaning efficiency. 4 cl
