TREATMENT OF TAIL GAS

摘要

PURPOSE:To thoroughly recover sulfur from a gas contg. sulfur components by converting a tail gas from an apparatus for recovering sulfur from the gas contg. sulfur components into gaseous SO2 in a catalytic oxidation apparatus and by returning the SO2 to the inlet duct of a reduction tower. CONSTITUTION:A gas contg. sulfur components is converted into SO2 in an elimination tower 1, reduced to S and H2S in a reduction tower 2, passed through a condenser 4, and fed to a Claus reactor 5 to produce SO2 once from the H2S and to recover S. After further separating S in a condenser 6, the tail gas is introduced into a main duct 9 at about 200 deg.C, supplied with air from a duct 8, and fed to a catalytic oxidation apparatus 11, where unreacted H2S, COS and vaporous S are oxidized to gaseous SO2. The SO2 is returned to the tower 2 through a duct 14', a damper 15a' and a duct 15. When the tail gas is not sufficiently oxidized, it is fed to a combustion furnace 13 and oxidized by combustion with air and fuel oil fed from ducts 13a, 13b, and the generated gaseous SO2 is returned to the tower 2 through ducts 14, 15.