Natural Gas Dehydration with Ionic Liquids

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• 作者：Gangqiang Yu ; Chengna Dai ; Liang Wu ; Zhigang Lei
• 刊名：Energy & Fuels
• 出版年：2017
• 出版时间：February 16, 2017
• 年：2017
• 卷：31
• 期：2
• 页码：1429-1439
• 全文大小：600K
• ISSN：1520-5029

文摘

The technology of natural gas dehydration with ionic liquids (ILs) as a promising method was proposed and systematically investigated in this work. The IL [EMIM][Tf₂N] was screened out as an appropriate absorbent from 252 IL candidates for the natural gas dehydration process by means of the COSMO-RS model. The σ-profiles and σ-potentials of the CH₄-H₂O-IL system were analyzed at the molecular level to explain the possibility of CH₄ dehydration using [EMIM][Tf₂N] as absorbent. The experiment data of CH₄ solubility in pure IL and in the mixture of IL + H₂O were measured and compared with the predicted results by the UNIFAC–Lei model. Moreover, the CH₄ dehydration experiment was carried out, and the gas product with a low water content (down to 350 ppm in mole fraction) can be obtained. Finally, the conceptual dehydration process was simulated and optimized using the rigorous equilibrium (EQ) stage model, into which the UNIFAC–Lei model parameters were input. It was found that the CH₄ dehydration process with [EMIM][Tf₂N] demonstrates the better separation performance, i.e., no solvent loss, plant miniaturization, and saving energy consumption, when compared to the benchmark triethylene glycol (TEG) process. Thus, ILs can be taken on as a type of promising alternative absorbents to conventional solvents in the field of gas dehydration.