Computation of the Dissociation Temperature of TBAB Semi-Clathrate in an Aqueous Solution Using Molecular Simulations.

Quaternary ammonium salts such as tetra-n-butyl ammonium bromide (TBAB) are known to form semi-clathrate hydrates. Since they form at much milder conditions compared to gas hydrates, they have evoked much interest in development of new technologies for gas storage and gas separations. In this work we present a method to compute the phase equilibrium of TBAB semi-clathrate. The TBAB molecule is modeled using OPLS-AA and GAFF forcefield and the results from simulations are compared with experimental data to determine the ability of the forcefield to accurately predict the semi-clathrate phase equilibria. It was observed that the OPLS-AA forcefield outperforms the GAFF forcefield in predicting the experimental phase equilibrium data.