咪唑基离子液体用于天然气脱水过程中的技术-环境评价

利用Aspen Plus建立离子液体天然气脱水的工艺流程模拟，结合灵敏度分析及生命周期评价方法，对该工艺应用不同离子液体产生的技术及环境影响进行比较，并分析离子液体结构对天然气脱水工艺技术及环境评价的影响。结果表明:与烷基链较短的阳离子结合的[BF₄]-离子液体具有较好的脱水性能（[EMIM][BF₄]>[BMIM][BF₄]>[OMIM][BF₄]）；对于生产1 kg甲烷气体而言，[BMIM][PF₆]脱水法的环境影响最大，达到[OMIM][BF₄]脱水法环境影响的5倍；此外，对于具有相同阴离子[BF₄]-的脱水情况，环境影响顺序为[OMIM][BF₄]<[BMIM][BF₄]<[EMIM][BF₄]。该结果从技术和环境评价的角度为筛选或开发天然气脱水过程中选择适当的离子液体提供了指导。

TECHNO-ENVIRONMENTAL ASSESSMENT IN NATURAL GAS DEHYDRATION WITH IMIDAZOLIUM-BASED IONIC LIQUIDS

The process flow simulation of imidazolium-based ionic liquids (ILs) used for natural gas (NG) dehydration was established by Aspen Plus. Technological and environmental impacts of different ILs in the NG dehydration process were compared by using the sensitivity analysis and life cycle assessment (LCA), and the IL structural effect on techno-environmental assessment in NG dehydration was evaluated. The results demonstrated that the ILs with[BF₄]- combined with the cation possessing the shorter alkyl chain exhibited better dehydration performance (the order following[EMIM] [BF₄]>[BMIM] [BF₄]>[OMIM] [BF₄]). For producing 1 kg methane, the largest environmental impact lay in the[BMIM] [PF₆] based dehydration process, and its impact was 5 times the lowest scenario using[OMIM] [BF₄] on average. Furthermore, for the dehydration scenarios with same anions[BF₄]-, the impact order was[OMIM] [BF₄]<[BMIM] [BF₄]<[EMIM] [BF₄]. The results can serve as a significant guidance strategy from both the technical and environmental assessment on screening or developing proper IL candidates for NG dehydration processes.