Cansolv尾气处理装置关键工艺参数对达标排放的影响及控制措施

Effects of key process parameters of Cansolv tail gas treatment unit on up-to-standard emission and control measures

关键词:  Cansolv  有机胺  尾气处理  SO₂  达标排放

Key words:  Cansolv  organic amine  tail gas treatment  SO₂  up-to-standard emission

摘要:

目的 确定Cansolv尾气处理装置关键工艺参数对尾气达标排放的影响,实现尾气中SO₂达标排放。方法 通过分析尾气SO₂排放的影响因素,认为排放尾气中SO₂质量浓度主要受进入Cansolv装置尾气中总硫含量、有机胺中热稳定盐含量、贫液pH值和DS溶液循环量等操作因素的影响。结果 通过以下措施优化了装置的工艺操作:①稳定脱硫装置操作,减少酸气、闪蒸气组成及流量的波动；②严格按照H₂S与SO₂体积比为2∶1进行配风控制；③控制进入SO₂吸收塔过程气的SO₃酸雾等杂质体积分数在10×10-6以下；④优化胺液净化装置的运行；⑤严格控制DS溶液系统中热稳定盐与DS有机胺物质的量之比为1.1~1.3；⑥控制DS贫液质量分数和贫度。结论 采取以上措施后,装置排放尾气中SO₂质量浓度≤400 mg/m³,满足GB 39728-2020《陆上石油天然气开采工业大气污染物排放标准》中硫磺回收装置总规模≥200 t/d时的SO₂质量浓度排放限值要求。 

Abstract:

Objective To determine the effect of key process parameters of Cansolv tail gas treatment unit on the tail gas emission, and achieve SO₂ in tail gas up-to-standard emission. MethodBy analyzing the factors affecting SO₂ mass concentration in tail gas, it is concluded that the SO₂ mass concentration in tail gas is mainly influenced by the operating factors such as total sulfur content in tail gas entering the Cansolv device, thermal stabilization salt content in organic amine, lean liquid pH value and DS solution circulation. Results The following measures have been taken to optimize the operation of the device:(1) The stable operation of the desulfurization device can be achieved by reducing the component and flow fluctuation of acid gas and flash gas; (2) The air distribution must be strictly controlled according to the volume ratio of H₂S to SO₂ is 2∶1; (3) The volume fraction of impurities must be controlled,such as SO₃ acid mist in the process gas entering the SO₂ absorption tower less than 10×10-6; (4) The operation of the amine purification device was optimized; (5) The molar ratio of thermally stable salt to organic amine in the DS solution system of 1.1~1.3 must be controlled strictlly; (6) The mass fraction and poverty of poor DS organic amine must be controlled. Conclusion sAfter taking above measures, the mass concentration of SO₂ in the exhaust gas was not greater than 400 mg/m³, which could meet the emission limit requirement in GB 39728-2020 Emission Standard of Air Pollutants for Onshore Oil and Gas Exploitation and Production Industry aiming at the total size of sulfur recovery unit greater than or equal to 200 t/d.