Abstract Hydrate technology is a promising alternative method for carbon dioxide (CO2) capture and storage from flue gas. In order to promote the hydrate growth rate and increase gas storage capacity, CO2 hydrate nucleation and growth induced by iron-based ionic liquid ([BMIM][FeCl4]) was studied with 400 rpm rotation speed at a temperature of 274.15 K and initial pressure of 5.0 MPa in this work. The induction time of CO2 hydrate formation was decreased by 52.8% and the storage capacity of CO2 hydrate was increased by 13.7% in 25.0 g/L [BMIM][FeCl4] solution. The local hydrogen bonds are strengthened by the combination interaction between the complex anion ([FeCl4]−) and water (H2O) molecules, which is favorable to the ordered arrangement and the proton exchange rate of H2O molecules during the hydrate nucleation. Besides, large mass transfer channels are formed by the large molar volume and regular tetrahedral structure of [FeCl4]− during the hydrate growth, which improves the diffusion rate of CO2 and H2O molecules in the solution to promote the hydrate growth. Distribution of lipophilic cation and hydrophilic anion with a large molecular volume of [BMIM][FeCl4] at the gas-liquid interface hinders the formation of cage structure of H2O molecules.

中文翻译：

---

铁基离子液体 ([BMIM][FeCl4]) 作为 CO2 水合物成核和生长的促进剂

摘要 水合物技术是一种很有前景的从烟道气中捕获和储存二氧化碳 (CO2) 的替代方法。为了提高水合物的生长速度和储气能力，研究了铁基离子液体（[BMIM][FeCl4]）在274.15 K和初始压力下，转速为400 rpm时CO2水合物的成核和生长在这项工作中为 5.0 MPa。在 25.0 g/L [BMIM][FeCl4] 溶液中，CO2 水合物形成的诱导时间减少了 52.8%，CO2 水合物的储存容量增加了 13.7%。局部氢键通过复合阴离子 ([FeCl4]-) 和水 (H2O) 分子之间的结合相互作用得到加强，这有利于水合物成核过程中 H2O 分子的有序排列和质子交换率。除了，[FeCl4]-的大摩尔体积和规则四面体结构在水合物生长过程中形成大的传质通道，提高了溶液中CO2和H2O分子的扩散速率，促进了水合物的生长。[BMIM][FeCl4]大分子体积的亲脂性阳离子和亲水性阴离子在气液界面的分布阻碍了H2O分子笼状结构的形成。