CPS+SCOT组合工艺停产尾气SO2减排措施探讨

Study on emission reduction measures of overhaul tail gas SO2 of CPS+SCOT combination process

关键词:  CPS+SCOT  SO₂排放  硫磺回收  尾气处理  除硫  减排措施  环保

Key words:  CPS+SCOT  sulfur dioxide emission  sulfur recovery  tail gas treatment  sulfur removal  emission reduction measures  environmental protection

摘要:

中石油遂宁天然气净化有限公司拥有国内大型天然气净化厂,硫磺回收和尾气处理采用CPS+SCOT组合工艺,硫回收率达99.8%,日常生产排放尾气中SO₂质量浓度低于300 mg/m³,远低于GB 16297-1996《大气污染物排放标准》中规定的960 mg/m³。为进一步减少检修停产过程中的SO₂排放量,对尾气管线进行优化改造。同时,在4列相同装置分列停产实例中,探索酸气除硫和燃料气除硫的最优方式,并对停产除硫过程中的问题进行总结探讨。结果 表明:在酸气除硫阶段,最好选择除一级甩开一级的方式,既不影响后续尾气处理装置正常运行,又保证了每一级反应器中硫磺去除更彻底；在燃料气除硫阶段,为确保SO₂排放达标,在时间允许的情况下,最好选择逐级甩开的方式。 

Abstract:

PetroChina Suining Natural Gas Purification Co., Ltd. posses a large natural gas purification plant in China, which uses CPS sulfur recovery + SCOT tail gas treatment combination process, and the sulfur recovery rate is 99.8%. The mass concentration of sulfur dioxide in tail gas is below 300 mg/m³ in daily production, far below the requirement of 960 mg/m³ in the national standard GB 16297-1996 Integrated Emission Standard of Air Pollutants. In order to further reduce sulfur dioxide emission during the maintenance and shutdown process, the tail gas pipelines optimization was carried out. At the same time, the optimal method of sulfur removal by acid gas and fuel gas was explored in the case of shutdown of the same four units, and the problems in the process of shutdown were summarized. The results showed that in the stage of sulfur removal by acid gas, it was better to choose the way of removing the stage of sulfur one by one, which will not only unaffect the normal operation of the following tail gas treatment units, but also ensure the sulfur removal in each stage of the reactor more thoroughly. In the stage of sulfur removal by fuel gas, in order to fully ensure the sulfur dioxide discharge to reach standard, it was better to choose the way of removing sulfur step by step if time is permitted.