Study On Dissolving Characteristics Of Mercury In Natural Gas Dehydration And Deacidification Solutions

Mercury in natural gas will dissolve into purification device and its separation fluids during dehydration and deacidification processes.Mercury emission from separation fluids into the environment will not only pose a great health threat to the operators,but also cause mercury pollution to the atmosphere,water and soil.Therefore,studying the dissolving characteristics of mercury in dehydration and deacidification solvents of natural gas and the distribution characteristics of mercury in gas field water and condensate,mastering the distribution law of mercury in the process of dehydration and deacidification of natural gas,mastering the distribution of mercury in natural gas dehydration and deacidification process can clarify the key points of mercury protection in the process of natural gas treatment containing mercury,help to select more efficient methods of mercury removal,and provide theoretical basis for systematic prevention and control of mercury pollution.In this paper,a new experimental device for the determination of mercury solubility was designed.The solubility of mercury in ethylene glycol,triethylene glycol,methanol,MDEA,gas field water and gas condensate was determined by equilibrium method.The results showed that the solubility of mercury in several solvents was significantly different.The properties of functional groups of organic matter and the interaction between mercury and solvent molecules had important effects on the solubility.Within the same temperature range,the order of mercury solubility is gas condensate > methanol > triethylene glycol > ethylene glycol > MDEA > gas field water,which is contrary to the polarity order of several solvents.Compared with ethylene glycol and triethylene glycol,methanol has stronger solubility to mercury and is more likely to be contaminated by mercury during natural gas dehydration.Secondly,according to the physical properties of solvents and the application conditions in natural gas dehydration and deacidification process,the corresponding temperature and pressure ranges were set respectively.The effects of temperature,pressure and solvent concentration on the solubility of mercury in ethylene glycol,triethylene glycol and MDEA were investigated experimentally.The results showed that the solubility of mercury increases with the increase of temperature,and shows a nearly exponential dependence on temperature.Pressure has a significant effect on the solubility of mercury at high temperature,which may be due to the strong volatility of mercury at high temperature,which makes the solubility of mercury increase with the increase of pressure.With the decrease of solvent concentration,the solubility of mercury in solvents decreased obviously.Finally,the solubility data of mercury in dehydration and deacidification solutions of natural gas were fitted by function model,and the solubility prediction equation was established.Thus,the solubility of mercury under the same conditions can be reasonably predicted,which can provide data reference for the study of mercury distribution in natural gas production process and guide the efficient environmental protection development of gas fields containing mercury.