Kinetic enhancement of capturing and storing greenhouse gas and volatile organic compound: Micro-mechanism and micro-structure of hydrate growth
Kinetic enhancement of capturing and storing greenhouse gas and volatile organic compound: Micro-mechanism and micro-structure of hydrate growth
复制标题
捕获和储存温室气体和挥发性有机化合物的动力学增强：水合物生长的微观机制和微观结构
DOI：
10.1016/j.cej.2019.122357
复制
发表时间：
2020-01-01
影响因子：
15.1
通讯作者：
Song, Yongchen
中科院分区：
文献类型：
--
作者：
Zhang, Lunxiang;Kuang, Yangmin;Song, Yongchen
使用基于水合物的技术进行天然气捕获和储存对于缓解环境影响非常有吸引力，因为它需要低能源损失，并提供最大的天然气储存密度和长期储存稳定性。尽管该方法已经进行了广泛的研究，但其发展受到潜在气体捕获微观机制不明确、储存形态微观结构难以捉摸以及水合物膜生长速度不足的限制。本研究采用磁共振成像技术分析了温室气体（以CO2、CH4和CO2-CH4混合气体的不同组分模拟）和挥发性有机化合物（以C2H4和C2H2模拟）捕获和储存的水合物生长微过程。添加288 ppm十二烷基硫酸钠（SDS）可促进水合物膜的生长，在烃类气体中，由于碳酸氢盐和十二烷基硫酸钠离子的竞争吸附，显著促进了水合物膜的生长，而在CO2气体中则没有。使用SDS，烃类气体水合物以65-105 mm/s的速度通过斑块模型生长，65-95%的液态水转化为水合物用于气体捕获和储存。然而，SDS仅将约1.4%的水转化为CO2水合物，速率为10.4 mm/s。因此，建立了一种二次水合物生长的多压力控制机制，以促进二氧化碳的捕获和储存，其基础是溶解的二氧化碳气体比其他所研究的气体多。增强的二氧化碳捕获对优化有害气体封存具有重要意义，因为水合物的形态优先是斑块状的，并且对渗透率有相关影响。
The use of hydrate-based technology for gas capture and storage is highly attractive for environmental mitigation, as it entails low energy penalties and provides gas storage density maximization and long-term storage stability. Although this method has been investigated in extensive researches, its development is restricted by the obscure underlying gas capture micro-mechanisms, elusive micro-structures of stored forms, and insufficient hydrate film growth rates. In this study, the Magnetic Resonance Imaging technique was employed to analyze the hydrate growth micro-processes for greenhouse gas (imitated by CO2, CH4, and various fractions of CO2-CH4 mixed gases) and volatile organic compound (simulated by C2H4 and C2H2 gases) capture and storage. The hydrate film growth was enhanced with the addition of 288 ppm sodium dodecyl sulfate (SDS), which significantly improved the hydrate growth in the cases of hydrocarbon gases, but not CO2 gas due to the competing adsorption of bicarbonate and dodecyl sulfate ions. With SDS, hydrocarbon gas hydrates grew via the patchy model at 65-105 mm/s, and 65-95% liquid water was converted into hydrates for gas capture and storage. However, only about 1.4% water was converted into CO2 hydrates with SDS, at 10.4 mm/s. Thus, a multi-pressure control mechanism for secondary hydrate growth was developed to promote CO2 capture and storage, based on a large amount of dissolved CO2 gas compared to the other investigated gases. The enhanced CO2 capture has important implications for the optimized harmful gas sequestration, due to preferentially patchy hydrate morphologies and associated impacts on permeability.