炼油厂硫磺回收工艺及催化剂的改进和优化

Improvement and optimization of sulfur recovery process and catalyst in a refinery

关键词:  宁夏石化  硫磺回收  尾气  SO₂  达标排放  钛基催化剂  双段吸收

Key words:  Ningxia Petrochemical  sulfur recovery  tail gas  SO₂  up-to-standard discharge  Ti-based catalyst  two-stage absorption

摘要:

中国石油宁夏石化分公司炼油厂5000 t/a硫磺回收装置改造前采用两级克劳斯+低温加氢还原吸收工艺,加氢后的尾气经过MDEA吸收,其排放烟气中SO₂质量浓度为500~800 mg/m³。其中,溶剂再生系统采用集中再生。根据中国石油西南油气田公司天然气研究院的设计工艺,工厂进行了全新的工艺改造,即采用天然气研究院生产的钛基催化剂增强水解和双段吸收工艺,成功解决了硫磺回收装置烟气中SO₂质量浓度达标排放的问题,排放烟气中SO₂质量浓度约50 mg/m³,可为小型硫磺回收装置,尤其是碱液碱渣处理困难的工厂的尾气达标排放提供技术思路及解决方案。 

Abstract:

The 5 000 t/a sulfur recovery unit in the refinery of PetroChina Ningxia Petrochemical Company used two-stage Claus and low temperature hydrogenation-reduction absorption process before improvement. The hydrogenated tail gas was absorbed by MDEA. The mass concentration of SO₂ in flue gas was 500-800 mg/m³. The method of centralized regeneration was adopted in solvent regeneration system. Based on the design process provided by Research Institute of Natural Gas Technology(RINGT), PetroChina Southwest Oil & Gasfield Company, the refinery carried out a new technology improvement. The hydrolysis was enhanced by Ti-based catalyst which was developed by RINGT and two-stage absorption process was applied. The SO₂ mass concentration in flue gas from sulfur recovery unit was about 50 mg/m³ after improvement, which had met the discharge standard. The technology improvement could provide technical ideas and solutions for the tail gas up-to-standard discharge of the small-scale sulfur recovery units, especially for the factories which are difficult to treat lye and alkali residue.