About Some Of The Properties Of A Guest Molecule Confined In A Water Network, In Order To Form A Clathrate

• Published in: Recent Developments in Physical Chemistry (AIP Conference Proceedings Volume 979) Vol. 979; pp. 3 - 10
• Main Authors: Perez, G Bravo, Cruz-Torres, A, Romero-Martinez, A
• Format: Journal Article
• Language: English
• Published: 01.01.2008
• ISBN: 9780735404984; 0735404984
• ISSN: 0094-243X
• DOI: 10.1063/1.2901845

At conditions of high pressure and or low temperature, like a sea bottom from even 1 Km deep, hydrates formation may take place. Its presence is facilitated at the water/oil interface inside conducting oil pipelines. Once formed, the hydrates nucleate further to agglomerations, sticking to the inner surface of the tube. This represents a big problem to flow assurance. We present results contributing to a better understanding of the interaction of a guest molecule with a water cage confining it, that give rise to a hydrate formation. The hydrate structure, its formation energy, and the role that the H bond and its cooperative effect in the water network play in the electrostatic dipole moment of the hydrate, are presented. Molecular calculations using the HF/6-311g(d, p), B3LYP/6-311g(d, p), and B3LYP/6-311++g(d,p) methods, have been applied to compare three different hydrates, each one confining one, two CH4 molecules, and a CO2 molecule, requiring respectively n = 14, 35, and 15 water molecules for the confinement.