天然气输送用乙二醇的再生工艺及模拟优化

Regeneration Process of Ethylene Glycol for Natural Gas Transmission and Its Simulation Optimization

天然气开采过程中极易形成水合物,在工业中常采用乙二醇作为水合物抑制剂,为降低天然气开采以及处理成本,乙二醇和水的混合物从天然气中被分离出来后常需精馏再生后循环利用,乙二醇富液再生过程能耗主要来自精馏塔。针对某海上油气开采项目中乙二醇再生装置能耗较大的问题,通过模拟软件Aspen HYSYS对乙二醇再生工艺系统进行分析,考察再生后乙二醇贫液浓度、再生塔进料温度、回流比对乙二醇再生工艺能耗的影响,并结合现场运行的实际情况对原有工艺进行节能优化。结果表明,当再生后乙二醇贫液浓度为89.00%(质量分数)、进料温度为100℃、回流比为0.23时,乙二醇再生工艺能耗相比原设计显著降低,优化后的工艺节能约729.6kW,根据优化工艺对现有设备进行更新后,固定成本增加约10万元,运行成本每年可节省约69.38万元。

Hydrate is easily formed during natural gas extraction,and ethylene glycol is often used as a hydrate inhibitor in industry.In order to reduce the cost of natural gas extraction and treatment,the mixture of ethylene glycol and water separated from natural gas is often recycled after distillation regeneration.The distillation tower is a major energy consumer in the regeneration of ethylene glycol rich liquid.For the high energy consumption problem of ethylene glycol regeneration unit in an offshore oil and gas extraction project,the simulation software Aspen HYSYS was used to analyze the ethylene glycol regeneration process system,the influences of the concentration of ethylene glycol lean liquid after regeneration,the feed temperature of regeneration tower and the reflux ratio on the energy consumption of ethylene glycol regeneration process were investigated,and energy saving optimization was carried out for the existing processes based on the actual operation on site.The results show that when the concentration of ethylene glycol lean liquid after regeneration is 89.00wt%,the feed temperature is 100℃and the reflux ratio is 0.23,the energy consumption of ethylene glycol regeneration process is significantly reduced compared with that of the original design,and the optimized process saves energy by about 729.6kW.After renewing the existing equipment according to the optimized process,the fixed cost is increased by about 100000yuan,and the operating cost can be saved by about 693800yuan per year.