High-efficiency process for production of sulfur from metallurgical sulfur dioxide gases

Abstract

Process in which sulfur is produced from a gas containing 25–55% SO₂ was studied in order to evaluate the real efficiency of the catalytic post-reduction of sulfur dioxide in a pilot unit with gas flow rate of up to 1.2 nm³ h^–1 at the following temperatures (°C): thermal stage 850–1100, catalytic conversion 350–570, and Claus reactor 219–279. It was found that the conversion at 400–550°C and space velocity of 1600 h^–1 on AOK-78-57 promoted aluminum oxide catalyst provides full processing of organosulfur compounds (CS₂ and COS). The temperature dependence of the conversion/generation of hydrogen sulfide on AOK-78-57 catalyst corresponds to the equilibrium model. It was experimentally confirmed that the homogeneous reduction of sulfur dioxide gas with methane at T ≈ 1100°C, with catalytic post-reduction at 400–550°C and subsequent Claus-conversion of the reduced gas at 230–260°C, provide a sufficiently deep (by 92–95%) general processing of sulfur dioxide gas to sulfur.