Anti-Agglomerator of Tetra-n-Butyl Ammonium Bromide Hydrate and Its Effect on Hydrate-Based CO2 Capture

Abstract

Tetra-n-butyl ammonium bromide (TBAB) was widely used in the research fields of cold storage and CO 2 hydrate separation due to its high phase change latent heat and thermodynamic promotion for hydrate formation. Agglomeration always occurred in the process of TBAB hydrate generation, which led to the blockage in the pipeline and the separation apparatus. In this work, we screened out a kind of anti-agglomerant that can effectively solve the problem of TBAB hydrate agglomeration. The anti-agglomerant (AA) is composed of 90% cocamidopropyl dimethylamine and 10% glycerol, which can keep TBAB hydrate of 19.3-29.0 wt. % in a stable state of slurry over 72 h. The microscopic observation of the morphology of the TBAB hydrate particles showed that the addition of AA can greatly reduce the size of the TBAB hydrate particles. CO 2 gas separation experiments found that the addition of AA led to great improvement on gas storage capacity, CO 2 split fraction and separation factor, due to the increasing of contact area between gas phase and hydrate particles. The CO 2 split fraction and separation factor with AA addition reached up to 70.3% and 42.8%, respectively.

Review of Ionic Semiclathrate Hydrates as Thermal Energy Storage Materials: Properties and Applications

“…Zhou et al reported that the maximum solid fraction required to keep a slurry pumpable was about 0.40 in mass fraction . Their conclusion was consistent with the theoretical relationship between the viscosity and solid fraction of the slurry reported by Graham et al The addition of an inhibitor of hydrate formation, such as a surfactant, is effective in suppressing the viscosity of a slurry. − Most recently, it was found that adding amino acids to a hydrate slurry reduces its viscosity, thereby reducing the pumping power consumption . Although representative surfactants such as sodium dodecyl sulfate and Span 80, which are not encapsulated in hydrate cages, serve as kinetic promoters for hydrate formation, the phase equilibrium temperature of hydrates undergoes very little change when adding the above surfactants to hydrate formation systems. , Conversely, adding additional guest compounds such as tetrahydropyran alleviate the phase equilibrium conditions …”

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

“…Although TBAB can considerably improve the phase equilibrium conditions for the CO 2 hydrate, the hydrate formed in the TBAB system easily agglomerates and deposits. Therefore, Li et al 165 added an antiagglomeration agent (AA) composed of 90% cocamide propyl dimethyl amine and 10% glycerol to the TBAB solution to improve the hydrate formation. The results indicated that AA can effectively prevent both the agglomeration of the TBAB-CO 2 hydrate and blockage of the separation equipment and improve the gas transfer in the hydrate phase, which considerably increases the hydrate separation efficiency.…”

A chromatographic approach for studying the adsorption of polar small molecules on tetrabutylammonium bromide semiclathrate hydrate

“…5 However, agglomeration of CHs is likely to occur in flow lines and industrial apparatus, and is a serious problem to be addressed. 6,7 A promising solution to this problem is injecting low-dosage hydrate inhibitors (LDHIs), which adsorb on a CH surface and interfere with the hydrate agglomeration. 8 To design more effective and environment-friendly synthetic inhibitors than the conventional substances, it is crucial to determine the mechanism of LDHI adsorption on CH surfaces.…”