(690f) Modeling the Effects of Interfaces on the Nucleation of Gas Hydrates and Ice in Porous Media
AIChE Annual Meeting
Thursday, November 14, 2019 - 1:38pm to 1:55pm
Heterogeneous nucleation takes place during the formation of gas-hydrates and ice in porous media. The presence of surfaces and interfaces within porous media can effectively lower the energy barrier for nucleation. The present work will introduce mathematical models developed in order to describe the effects on energy barriers during heterogeneous nucleation of ice or gas hydrates in porous media. Three different types of interfaces found in these environments will be discussed: a) gas/liquid interfaces, b) solid surfaces, and c) gas/liquid/solid triple boundary lines.
Model predictions suggest that nucleation is more energetically favorable on solid surfaces than at the gas/liquid interface or triple boundary line. In the case of solid surfaces, nucleation is favored within concave surfaces (e.g., inside porous spaces) and to a lesser extent on convex surfaces (e.g., particulates), while flat surfaces act as the behavioral boundary between these two cases. Additionally, hydrophilicity of solid surfaces enhances the positive effect of these surfaces towards nucleation. In the case of gas/liquid interfaces and triple boundary lines, nucleation and crystal growth occur preferentially within the liquid phase rather on the gas phase, and it is favored when the gas/liquid interfaces are present between slightly hydrophobic surfaces.