天然气净化厂尾气加氢催化剂认识与实践

Recognition and practice of tail gas hydrogenation catalyst used in natural gas purification plant

关键词:  天然气净化  克劳斯  尾气  加氢  催化剂  动力学  水解

Key words:  natural gas purification  Claus  tail gas  hydrogenation  catalyst  kinetics  hydrolysis

摘要:

目的 开发一种高性能的尾气加氢催化剂,以解决硫磺回收装置排放烟气中SO₂质量浓度超标的问题。方法 对天然气净化厂尾气处理装置加氢催化剂活性组分对加氢、水解和变换等主要化学反应的催化性能进行了研究。通过微反应和动态表征技术进行催化剂动力学研究,获取其加氢与水解反应的活化能与反应级数,从而提升催化剂性能。结果 研究结果表明,氢气吸附在钴钼加氢催化剂上后对SO₂加氢有一定的抑制作用,水吸附在催化剂上后对COS水解有很强的抑制和阻碍作用。依托催化剂活性组分和动力学研究结果,开发了一种加氢催化剂。结论 与镍钨和铁钼催化剂相比,该催化剂的SO₂与硫磺加氢性能、有机硫水解性能、CO变换性能均较好,适用于天然气净化厂与炼油厂的操作工况,可实现尾气处理装置排放烟气中SO₂质量浓度低于400 mg/m³的目标。 

Abstract:

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. Conclusion sCompared 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.