天然气净化装置胺液系统中杂质成分及来源分析

Analysis of the impurity composition and source in the amine liquid system of the combined unit of the purification plant

普光气田净化装置已经运行超过10年,该厂采用醇胺溶剂法脱除天然气中的酸性气体。随着时间的增加,胺液中累积的各种杂质导致脱硫选择性下降,悬浮物、黏泥等杂质附着在换热器管壁,导致换热器运行效率下降,严重影响胺液吸收。利用XRF、XRD、SEM、ICP-AES和离子色谱仪等技术手段分别对换热器管壁的黏泥、胺液中的有机成分和热稳定盐进行了分析,并探究了各种杂质成因和来源。胺液中的Fe^(3+)来源于设备腐蚀,SO_(4)^(2-)和S_(2)O_(3)^(2-)来自H_(2)S的氧化,有机酸根离子HCOO-和CH_(3)COO^(-)来自MDEA氧化降解。为解决胺液吸收能力减弱,改善换热器设备腐蚀及溶液发泡等问题提出了相应的技术优化措施。

The Puguang gas field purification plant has been in operation for more than 10 years.The plant uses the alcohol amine solvent method to remove acid gases from natural gas.With the increase of time,various impurities accumulated in the amine liquid lead to a decrease in desulfurization selectivity.Impurities such as suspended solids and slime adhere to the tube wall of the heat exchanger,resulting in a decrease in the operation efficiency of the heat exchanger and seriously affecting the absorption of the amine liquid.The components of the sludge on the tube wall of the heat exchanger,the organic components in the amine solution and the heat stable salts were analyzed by using XRF,XRD,SEM,ICP-AES and ion chromatogragh,and the causes and sources of various impurities were explored.Fe^(3+)in the amine solution comes from equipment corrosion,SO_(4)^(2-)and S_(2)O_(3)^(2-)from H_(2)S oxidation,and organic acid ions HCOO^(-)and CH_(3)COO^(-)from MDEA oxidative degradation.In order to solve the problem of weakening of the amine liquid absorption capacity,improve the corrosion of heat exchanger equipment and solution foaming,corresponding technical optimization measures are proposed.