Use of Hydrophobic Particles as Kinetic Promoters for Gas Hydrate Formation

Abstract

Hydrophobic particles have been tested as kinetic promoters for gas hydrate formation. The experimental results obtained with stationary beds of sands show that methane (CH4) hydrate is more readily formed when the sand particles are hydrophobized by coating the surfaces with octadecyltrichlorosilane (OTS). The induction times decreased steadily with increasing water contact angles (θ) possibly due to the increased propensity of the water molecules in the vicinity of hydrophobic surfaces to form partial clathrates. The kinetics of CO2 hydrate formation has been studied using Teflon and hydrophobic silica particles to disperse either water in gas phase to obtain “dry water” or to disperse gas in water phase to obtain foam. The results show that hydrates are formed instantaneously due to the increased mass transfer rates at the gas/water interface and the formation of partial clathrates in the vicinity of hydrophobic surfaces.