Kinetics of Methane Hydrate Formation in the Presence of Silica Nanoparticles and Cetyltrimethylammonium Bromide

Abstract

Hydrate technology promoted the development of natural gas industry. Nanoparticles showed a broad prospect for hydrate technology because of their excellent mass and heat transfer characteristics. At an experimental temperature of 275.15 K and pressure of 5 MPa, silica nanoparticles and cetyltrimethylammonium bromide (CTAB) were used to investigate the characteristics (pressure drop, gas storage capacity, and formation rate). The experimental results showed that the higher the concentration of silica nanofluid, the shorter the induction time. Among the four silica nanoparticles concentration (0.1, 0.2, 0.3, and 0.5 wt%) tested in this work, the concentration of 0.3 wt% was optimal for the enhancement of CH4 hydrate formation. In the complex system composed of silica nanoparticles and CTAB, the surface of silica nanoparticles was positively charged by hydrolysis. The cationic active groups ionized by surfactants were aggregated to the surface of the particles under the Coulomb force. Methane molecules were gathered to hydrophobic groups by non‐polar adsorption, which was more conducive to hydrate formation. Compared to silica nanofluid, the total time for hydrate formation decreased by 66.2 %.

Effect of Silica Nanoparticles to Span 80 and Cocamidopropyl Dimethylamine in Methane Hydrate Formation and Agglomeration in Water–Oil System

“…In this way, the combination application of CPKO + nanoparticles exhibited promising potential as efficient hydrate AAs and KHI. Zhai et al investigated the hydrate formation kinetics with the presence of silica nanoparticles and a hydrophilic surfactant (cetyltrimethylammonium bromide) at the temperature of 275.15 K and pressure of 5 MPa. Results showed that the hydrate induction time was shortened with the increase of nanoparticle concentration from 0.1 wt % to 0.5 wt %.…”

“…In this work, the hydrate induction time also decreased with the increase of OSN concentration from 0.1 wt % to 0.5 wt %. It was suggested by Zhai et al that the cationic active groups of surfactants will be aggregated to the nanoparticles surface driven by the Coulomb force, and methane molecules will gather to hydrophobic groups by nonpolar adsorption, which may contribute to the hydrate formation than the nanoparticle only system.…”