Understanding the effect of moderate concentration SDS on CO2 hydrates growth in the presence of THF.
Understanding the effect of moderate concentration SDS on CO2 hydrates growth in the presence of THF.
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DOI：
10.1016/j.jcis.2023.11.136
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发表时间：
2023-11
影响因子：
9.9
通讯作者：
Xinrui Cai;Joshua Worley;A. Phan;Matteo Salvalaglio;Carolyn Koh;A. Striolo
中科院分区：
文献类型：
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作者：
Xinrui Cai;Joshua Worley;A. Phan;Matteo Salvalaglio;Carolyn Koh;A. Striolo
假设四氢呋喃（THF）和十二烷基硫酸钠（SDS）等添加剂单独使用时可提高二氧化碳（CO2）水合物的热稳定性和生长速率。模拟与实验采用原子分子动力学模拟方法研究了不同温度和浓度下四氢呋喃和十二烷基硫酸钠对CO2水合物生长的影响。模拟的见解进行了实验验证，在环境压力和高压差示扫描量热仪进行悬垂滴张力测定法findingsOur模拟显示，这两种添加剂的组合是协同作用，在低温下，但在274.1 K以上的温度下，由于THF分子诱导的SDS分子的聚集拮抗。这些聚集体有效地从水合物-液体界面去除THF和CO2，从而降低水合物生长的驱动力。实验表明，加入THF后，SDS在水中的临界胶束浓度降低了20%。进一步的实验表明，在THF的存在下，只有少量的SDS是足以增加超过40%的CO2存储效率相比，没有促进剂获得的结果。总体而言，我们的研究结果提供了微观的洞察力的THF和SDS促进剂对CO2水合物的机制，用于确定水合物生长的最佳条件。
HypothesisAdditives like Tetrahydrofuran (THF) and Sodium Dodecylsulfate (SDS) improve Carbon Dioxide (CO2) hydrates thermal stability and growth rate when used separately. It has been hypothesised that combining them could improve the kinetics of growth and the thermodynamic stability of CO2hydrates.Simulations and ExperimentsWe exploit atomistic molecular dynamics simulations to investigate the combined impact of THF and SDS under different temperatures and concentrations. The simulation insights are verified experimentally using pendant drop tensiometry conducted at ambient pressures and high-pressure differential scanning calorimetry.FindingsOur simulations revealed that the combination of both additives is synergistic at low temperatures but antagonistic at temperatures above 274.1 K due to the aggregation of SDS molecules induced by THF molecules. These aggregates effectively remove THF and CO2from the hydrate-liquid interface, thereby reducing the driving force for hydrates growth. Experiments revealed that the critical micelle concentration of SDS in water decreases by 20% upon the addition of THF. Further experiments in the presence of THF showed that only small amounts of SDS are sufficient to increase the CO2storage efficiency by over 40% compared to results obtained without promoters. Overall, our results provide microscopic insights into the mechanisms of THF and SDS promoters on CO2hydrates, useful for determining the optimal conditions for hydrate growth.