CO2脱除是天然气预处理等工业过程的重要工序之一,在天然气终端处理厂,特别是海上气田陆上终端,受气田开采周期及产量波动影响,装置通常分期建设,往往导致脱碳单元设计工况与实际工况偏差较大.针对实际工况合理选择操作参数对装置稳定运行、节能降耗及提高经济效益有重要意义.应用Aspen HYSYS软件对某天然气陆上终端一套采用MDEA工艺的脱碳装置进行了模拟及优化.对闪蒸塔压力、贫液及半贫液循环量配比等参数进行工况研究的结果表明:对于该装置,闪蒸塔压力由680 kPa调整为830 kPa,即富液压降为2250 kPa时,回收闪蒸气生产脱碳气,可以解决吸收塔底富液闪蒸气放空的问题;同时,贫液循环量由120 m 3/h调整为100 m 3/h,半贫液循环量调整为470 m 3/h时能够有效降低脱碳工序能耗,增加脱碳气产量.研究结果对现场生产实现降本增效具有参考作用,闪蒸气回收方案在同类型装置中具有一定的推广性.%CO 2removal process occupies an important position in industries such as natural gas pretreatment. In natural gas refining plant,especially for offshore gas field,off design conditions are quite normal in CO 2removal unit due to yield fluctuation. In this paper, function of case studies in Aspen HYSYS was used in simulation of CO 2removal process using MDEA amine to find optimal operation parameters such as flash column pressure,ratio between lean amine and semi lean solution. It was shown that the operating parameters of flash column pressure was adjusted from 680 kPa to 830 kPa,which means when liquid pressure drop was 2 250 kPa, the flash gas was recyclable. As for a further comment, when lean solution circulation was adjusted from 120 m 3/h to 100 m 3/h, and semilean solution circulation adjusted to 470 m 3/h, lower energy consumption and better economic benefit would be achieved in this CO 2removal process. The case study can be used as a guide to realize cost reduction and efficiency enhancement in field production,and the design of flash gas recovery can be promoted in similar unit.
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