Experimental measurement and thermodynamic modeling of cyclopentane hydrates with NaCl, KCl, CaCl2, or NaCl-KCl present

Consistent phase equilibrium data for cyclopentane hydrates in presence of salts are vitally important to many industries, with particular interest to the field of hydrate-based water separation via cyclopentane hydrate crystallization such as desalination. However, there are very little experimental equilibrium data, and no thermodynamic prediction tools. Hence, we set up a method to generate a great deal of much needed equilibrium data for cyclopentane hydrates in diverse saline solutions with a wide range of salt concentrations. Our method does furnish verified, reliable and accurate equilibrium data. Plus, three thermodynamic approaches are developed to predict equilibrium, and provide tools for simulations, by considering the kind of salt and concentrations. All three models are in very good accordance with experimental data. One method, using a new correlation between occupancy factor and water activity, might be the best way to obtain consistent, quick, and accurate dissociation temperatures of cyclopentane hydrate in brine. (c) 2018 American Institute of Chemical Engineers AIChE J, 64: 2207-2218, 2018