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

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SO_(2)达标排放。方法通过分析尾气SO_(2)排放的影响因素,认为排放尾气中SO_(2)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H_(2)S与SO_(2)体积比为2∶1进行配风控制;(3)控制进入SO_(2)吸收塔过程气的SO_(3)酸雾等杂质体积分数在10×10^(-5)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SO_(2)质量浓度≤400 mg/m^(3),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SO_(2)质量浓度排放限值要求。

Objective To determine the effect of key process parameters of Cansolv tail gas treatment unit on the tail gas emission,and achieve SO_(2)in tail gas up-to-standard emission.Method By analyzing the factors affecting SO_(2)mass concentration in tail gas,it is concluded that the SO_(2)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 H_(2)S to SO_(2)is 2∶1;(3)The volume fraction of impurities must be controlled,such as SO_(2)acid mist in the process gas entering the SO_(2)absorption tower less than 10×10^(-5);(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.Conclusions After taking above measures,the mass concentration of SO_(3)in the exhaust gas was not greater than 400 mg/m^(3),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.