Hydrates for Cold Storage: Formation Characteristics, Stability, and Promoters

Abstract

The potential of hydrates formed from R141b (CH3CCl2F), trimethylolethane (TME), and tetra-n-butylammonium bromide/tetra-n-butylammonium chloride (TBAB/TBAC) to be used as working substances for cold storage was investigated to provide a solution for unbalanced energy grids. In this study, the characteristics of hydrate formation, crystal morphology of hydrates, and the stability of hydrate in cyclic formation under 0.1 MPa and at 5 °C were carried out. It found that the ice had a positive effect on the hydrate formation under same conditions. Upon the addition of the ice cube, the induction time of R141b, TME, and TBAB/TBAC hydrates decreased markedly, and significantly high formation rates were obtained. Under magnetic stirring, the rate at which TBAB/TBAC formed hydrates was significantly lower than that when ice was used. In microscopic experiments, it was observed that the TBAB/TBAC mixture formed hydrates with more nucleation sites and compact structures, which may increase the hydrate formation rate. In the multiple cycle formation of TBAB/TBAC hydrates, the induction time gradually decreased with the increasing number of formation cycles and finally stabilized, which indicated the potential of the TBAB/TBAC hydrates for application in cold storage owing to their good durability and short process time for heat absorption and release.

Energy Storage in Hydrates: Status, Recent Trends, and Future Prospects

“…Cold energy storage in hydrates is also perceived as a form of energy storage in hydrates; however, as mentioned in the first paragraph of the introduction, the scope of this review excludes the thermal based energy storage aspects. Several comprehensive reviews on cold energy storage in hydrates are found in literature. − Readers can refer to them to gather insight and knowledge about the research progress in this domain. Before examining methane and hydrogen storage in hydrates, a brief introduction on gas hydrates, their structures, and other applications is discussed.…”

Review on Cooperative Effect of Compound Additives on CO2 Hydrate Formation: Recent Advances and Future Directions

“…Research has shown that CO 2 emissions are an important cause of global warming and climate change. , To mitigate global warming and reduce CO 2 emissions, the capture and storage of CO 2 from the atmosphere and industrial production has attracted global attention. , Hydrate-based CO 2 sequestration (HCS) is a hot topic in hydrate utilization research and is an effective method to reduce CO 2 emissions . In addition, gas hydrate technology has been applied to seawater desalination, − mixed gas separation, , hydrate cooling storage, − and CO 2 –CH 4 replacement. − …”

Hydrate Phase Equilibrium Data of Dimethyl Ether in the Presence of Tetrahydrofuran, Tetra-n-butylammonium Bromide, and Cyclopentane

“…) − and a nongas hydrate (such as semi-clathrate hydrate TBAB, TBAAc, etc. ). − A Gas hydrate, compared with a nongas hydrate, has a high cold storage density . However, it needs to provide a higher pressure to meet a suitable phase transition temperature, which limits its application.…”

“…11−13 A Gas hydrate, compared with a nongas hydrate, has a high cold storage density. 14 However, it needs to provide a higher pressure to meet a suitable phase transition temperature, which limits its application. Some studies have pointed out that thermodynamic additives can be used to alleviate the harsh phase equilibrium condition of a gas hydrate, thus, making it close to a region of low pressure and high temperature.…”