Upgrading Technology for Sulfur Removal from Coke Gas

摘要

The coke gas purification technology implemented at the Magnitogorsk Integrated Metallurgical Works incorporates hydrogen sulfide capture with aqueous ammonia solution and its subsequent conversion by the Claus method to obtain sulfur, after which the "tail gas" from the Glaus conversion is returned to the raw coke gas, supplementing the hydrogen sulfide supply [1]. The presence in the tail gas from the hydrogen sulfide conversion section (Claus unit) of elemental sulfur, which is deposited in the gas lines and on the equipment, creates additional operational difficulties [2]. The known methods for complete sulfur extraction employed in the gas industry [3] seem overly cumbersome and capital-intensive in our case. Thermodynamic analysis results [4] lead to the conclusion that another possible way to solve the problem consists in hydrolyzing the tail gas sulfur; the thermodynamic hydrogen sulfide yield at 700-900 K is 99.7 rel. percent ; there is no elemental sulfur or SO_2 in the equilibrium system [4]. The results of commercial-scale trials [5] confirm the feasibility of hydrogen sulfide generation at >550 K. However, the composition of the tail gases from a Claus unit differs substantially from that investigated in publications [4, 5], This necessitated exploratory studies, which were performed at ZAO Russian Metallurgical Company (ZAO RMK).