Chemical free energies, hydration forces

Experimental information on gas hydrate nucleation at a microscopic level is almost nonexistent or at best very limited. Most of the studies on the hydrate nucleation are based on a macroscopic approach. Although there are some differences, gas hydrate nucleation has similarities with salt crystal nucleation. For the nucleation to occur, supersaturation of the aqueous solution with the hydrate former gas is required. The supersaturation is necessary to overcome the free energy barrier for creating a new surface of a solid hydrate nucleus. The degree of supersaturation or the driving force for nucleation may be defined in terms of difference in the chemical potential or the fugacity of a hydrate former in the solution and that at the... 

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