1. Kinetic enhancement of capturing and storing greenhouse gas and volatile organic compound: Micro-mechanism and micro-structure of hydrate growth.
- Author
-
Zhang, Lunxiang, Kuang, Yangmin, Dai, Sheng, Wang, Jiaqi, Zhao, Jiafei, and Song, Yongchen
- Subjects
- *
VOLATILE organic compounds , *METHANE hydrates , *SODIUM dodecyl sulfate , *BICARBONATE ions , *GREENHOUSE gases , *GAS hydrates , *HYDRATES , *GAS storage - Abstract
Kinetic enhancement for capturing and storing harmful gases into hydrates simultaneously to achieve low energy penalties and environmental mitigations. • Kinetic surfactants accelerate gas captures in pore spaces. • Oscillated pressure controls are first proposed to enhance CO 2 gas captures. • Enhanced gas capture processes change microstructural features. • The hydrate technology is a safely long-term storages of harmful gases. 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 CO 2 , CH 4 , and various fractions of CO 2 -CH 4 mixed gases) and volatile organic compound (simulated by C 2 H 4 and C 2 H 2 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 CO 2 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 CO 2 hydrates with SDS, at 10.4 mm/s. Thus, a multi-pressure control mechanism for secondary hydrate growth was developed to promote CO 2 capture and storage, based on a large amount of dissolved CO 2 gas compared to the other investigated gases. The enhanced CO 2 capture has important implications for the optimized harmful gas sequestration, due to preferentially patchy hydrate morphologies and associated impacts on permeability. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF