Abstract: In response to the issues of prolonged start-up time during the pre-sulfidation process of the original oxidized-state tail gas hydrogenation catalyst and high SO₂ emissions in the flue gas, a sulfided-state tail gas hydrogenation catalyst was adopted in the hydrogenation reactor of a 40 kt/a sulfur recovery unit at a certain company. This article summarizes the operational procedures and precautions for the sulfided-state tail gas hydrogenation catalyst during start-up, and analyzes its practical application performance and advantages. The results show that the sulfided-state tail gas hydrogenation catalyst can be safely put into operation, the start-up time significantly reduced, saving fuel gas, hydrogen, and electricity consumption, and lowering operational costs by 67 000 yuan. During the start-up period, SO2 emissions were reduced by 98%. The performance of the sulfided-state tail gas hydrogenation catalyst meets the requirements for long-term stable operation of the sulfur recovery unit, demonstrating significant environmental benefits.

Key words: sulfur recovery, tail gas, hydrogenation catalyst, pre-sulfidation, sulfided type, SO2