Cansolv尾气处理装置对天然气净化厂的影响及优化措施探讨

目的为了使天然气净化厂尾气排放满足GB 39728-2020《陆上石油天然气开采工业大气污染物排放标准》的要求,已建天然气净化厂须新建尾气处理装置使尾气排放达标,Cansolv工艺在天然气净化厂陆续应用,实现了尾气较低含量的SO₂排放和经济运行。 方法通过对忠县天然气净化厂新建Cansolv尾气处理装置投产以来的运行调整总结,摸索影响装置正常运行的主要因素,对3种情况进行了统计分析:①废水水质、废气中SO₂排放；②Cansolv尾气处理装置能耗和化工原材料消耗；③影响Cansolv尾气处理装置产生污染物的因素,最终对Cansolv尾气处理装置实施以下优化措施:①优化装置运行参数,达到尾气SO₂排放要求；②合理控制装置DS溶液中热稳定性盐含量,减少废水量；③合理控制DS溶液及烟气温度,减少废水量；④提高湿式电除雾器运行稳定性,减小溶液中热稳定性盐含量；⑤合理调整中和废水水质,提高DTRO处理橇淡水收率；⑥硫磺回收装置开、停车过程中,优化装置操作；⑦调整装置运行,减少能耗及化工原料消耗。 结果Cansolv尾气处理装置运行措施优化后,保证了尾气较低含量的SO₂排放；废水产生量得到有效的减少和控制；同时,在节能方面得到较大的提高。 结论通过Cansolv尾气处理装置对天然气净化厂的影响分析及运行措施优化,使Cansolv尾气处理装置达到了高效、安全、平稳运行的目的,为今后新建的Cansolv尾气处理装置提供运行经验。 

Influence of Cansolv tail gas treatment unit on natural gas purification plant and discussion on optimization measures

ObjectiveIn order to meet the specification requirements of the GB 39728-2020 Emission standard of pollutants for onshore oil and gas exploitation and production industry, a new tail gas treatment unit was needed for the built natural gas purification plant and production. Cansolv process has been successively applied in the natural gas purification plant to realize the low concentration SO₂ emission of tail gas and economic operation. Methods According to the operation adjustment summary of the new Cansolv tail gas treatment unit in Zhongxian Natural Gas Purification Plant since it was put into operation, the main factors affecting the normal operation of the unit were explored. The statistical analysis includes the following contents:(1) wastewater quality and SO₂ emission in waste gas; (2) energy consumption of Cansolv tail gas treatment unit and consumption of chemical raw materials; (3) factors affecting pollutants produced by Cansolv tail gas treatment unit. The following optimization measures are implemented for Cansolv tail gas treatment unit:(1) optimize the operation parameters of Cansolv tail gas treatment unit to meet the requirements of tail gas SO₂ emission; (2) reasonably control the content of thermal stability salt in DS solution of Cansolv tail gas treatment unit to reduce the amount of waste water; (3) reasonably control the temperature of DS solution and flue gas of Cansolv tail gas treatment unit to reduce the amount of waste water; (4) improve the operation stability of wet electric mist eliminator to reduce the thermal stability salt content in the solution; (5) reasonably adjust the quality of neutralization wastewater to improve the yield of fresh water from DTRO treatment skid; (6) optimize the operation of Cansolv tail gas treatment unit during the startup and shutdown of sulfur recovery unit; (7) adjust the energy consumption of Cansolv tail gas treatment unit to reduce the energy consumption of chemical raw materials. ResultsAfter optimizing the operation measures of Cansolv tail gas treatment unit, the low concentration SO₂ emission of tail gas was ensured while wastewater production has been effectively reduced and controlled. Meanwhile, energy saving has been greatly improved. ConclusionsThrough the analysis on the influence of Cansolv tail gas treatment unit on the natural gas purification plant and the optimization of operation measures, the Cansolv tail gas treatment unit can achieve efficient, safe and stable operation, which would provide reference for new Cansolv tail gas treatment in the future.