CO₂ Hydrate Formation Kinetics in the Presence of a Layered Double Hydroxide Nanofluid

Abstract

The effects of a hybrid nanofluid (Cu-Al layered double hydroxide (LDH)) on the CO 2 hydrate formation kinetics was investigated at three different nanofluid concentrations (0.25-1.0 wt %). The Cu-Al LDH nanofluid was prepared using a one-step co-precipitation technique. The addition of the LDH nanofluid reduces the induction time and enhances the hydrate formation kinetics. The maximum reduction in the induction time (by 91.08 %) was observed at the optimal nanofluid concentration of 0.5 wt %, compared to water. A chemical affinity model was implemented to predict the experimental data for CO 2 hydrate formation in the presence of the different LDH nanofluid concentrations. An artificial neural network-based Levenberg-Marquardt model predicts the experimental data with higher accuracy than the scaled conjugate gradient model. The results indicate a strong dependency of the hydrate formation kinetics on the LDH nanofluid concentrations.

Can Aluminum Cations Promote Nucleation for THF Hydrate Growth?

“…The close-to-neutral pH (5 < pH < 8) can lead to the formation of aluminum hydroxide, which may exist as a suspension of nanoparticles . The formation of nanoparticles might reduce induction time by creating more nucleation sites . Sun et al reported that nonanoic acid with THF + water emulsion formed small crystal particles, eventually decreasing the induction time.…”

“…Clathrate hydrates (hereafter hydrates) are a specific category of clathrates, where hosts are hydrogen-bonded with water molecules. 1 The hydrate studies are essential for several technological applications such as gas storage and transportation, 2 water desalination, 3 CO 2 sequestration, 4 and prevention of pipeline plugging. 5−7 Understanding hydrate formation thermodynamics and kinetics is key to the development of hydrate-based technologies.…”

“…The stable thermodynamic conditions of hydrates are primarily dependent on the type of guest molecules and the presence of external additives. 2,4,8 The nucleation kinetics 9 and propagation of the hydrate front dominate gas hydrate formation kinetics. Induction time evaluation captures the nucleation kinetics.…”

“…The hydrate studies are essential for several technological applications such as gas storage and transportation, water desalination, CO 2 sequestration, and prevention of pipeline plugging. − Understanding hydrate formation thermodynamics and kinetics is key to the development of hydrate-based technologies. The stable thermodynamic conditions of hydrates are primarily dependent on the type of guest molecules and the presence of external additives. ,, The nucleation kinetics and propagation of the hydrate front dominate gas hydrate formation kinetics. Induction time evaluation captures the nucleation kinetics…”