Tail gas treatment
Natural Gas Treatment

On leaving the Claus unit, after conversion of the H₂S in the acid gas into sulfur, the gas cannot be released into the atmosphere or sent to the incinerator without additional treatment, due to the residual H₂S content and the presence of SO₂ from the first stage of the Claus reaction, which converts H₂S into SO₂ by oxidation. H₂S and SO₂ contents are a few hundred ppmv, although these can be reduced by implementing Superclaus-type technology. The standard relating to the limitation of discharges into the atmosphere imposes a limit value of 35 mg/m³ of sulfur oxides (value expressed in SO₂ equivalent). A treatment of this gas must therefore be carried out before it can be sent to the incinerator in order to eliminate the SO₂ and also the residual H₂S, which would lead to a formation...