Objective A good performance tail gas hydrogenation catalyst was developed to solve the problem of excessive SO₂ mass concentration in flue gas discharged from sulfur recovery unit.

Methods The catalytic performance of active components of hydrogenation catalyst in tail gas treatment unit of natural gas purification plant for the main chemical reactions such as hydrogenation, hydrolysis and transformation was studied. The catalyst kinetics was studied by micro-reaction and dynamic characterization techniques to obtain the activation energy and reaction order of hydrogenation and hydrolysis reactions, so as to improve the catalyst performance.

Results Hydrogen adsorption on Co-Mo hydrogenation catalyst could inhibit the hydrogenation of SO₂, and water adsorption on the catalyst could strongly inhibit and hinder the hydrolysis of COS. A hydrogenation catalyst was developed based on the research results of catalyst active components and kinetics.

Conclusions Compared with Ni-W and Fe-Mo catalysts, the new developed catalyst has better SO₂ and sulfur hydrogenation performance, organic sulfur hydrolysis performance and CO conversion performance. It is suitable for the operating conditions of natural gas purification plant and refinery, and can achieve the goal of SO₂ mass concentration less than 400 mg/m³ in the flue gas discharged from tail gas treatment unit.