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.a Dh b2L w j T 0 ;P 0 5 Dl b2I w j T 0 ;P 0 -6011, where 6011 is the enthalpy of ice (J mol 21 ).

This article presents a systematic review on the past developments of Hydrate-Based Desalination process using Cyclopentane as hydrate guest. This is the first review that covers all required fundamental data, such as multiphase equilibria data, kinetics, morphology, or physical properties of cyclopentane hydrates, in order to develop an effective and sustainable desalination process. Furthermore, this state-of-the-art describes research and commercialization perspectives. When compared to traditional applications, cyclopentane hydrate-based desalination process could be a promising solution. Indeed, it operates under normal atmospheric pressure, lower operation energies are required, etc… However, there are some challenges yet to overcome. A decision aid in the form of a diagram is proposed for a new cyclopentane hydrates-based desalination process. Hopefully, concepts reviewed in this study will suggest new ideas to advance technical solutions in order to make commercial hydrate-based desalination processes a reality.

Clathrate hydrates most often grow at the interface between liquid water and another fluid phase (hydrocarbon) acting as a provider for the hydrate guest molecules, and some transfer through this shell is required for the hydrate growth to proceed, thus self-limiting the reaction rate. An optical microscope and a horizontal reaction cell are utilized to capture the shell growth phenomenology and to estimate the hydrate layer growth rates from sequential pictures. Cyclopentane (CP) is chosen as the hydrate-forming molecule to obtain hydrates at low pressure. Experimental hydrate layer growth rates are provided for the CP+brine system, using various combinations of salts and degrees of subcooling.

Cyclopentane hydrates-based salt removal is considered to be a possible promising technology for desalination. In order to optimize such processes, phase equilibrium data of Cyclopentane Hydrates (CPH) in saline solutions are crucial. Lamentably, these data sets are still incomplete.Therefore, earlier we published a limited experimental and modeling study on CPH equilibrium with some salts present.This study extends experimental equilibrium to four more common brine systems: Na 2 SO 4 , MgCl 2 , MgCl 2 -NaCl, or MgCl 2 -NaCl-KCl at various salt concentrations. Importantly, four thermodynamic approaches: the Standard Freezing Point Depression equation based (SFPD), Hu-Lee-Sum (HLS) correlation, and the two van der Waals and Platteuw-based Kihara and Activity-Based Occupancy Correlation (ABOC) methods, are compared to this new set of experimental data. Results show that simulations agree adequately with measured data. Nonetheless, the ABOC method is the best model to reproduce rapid and consistent equilibrium data of CPH in brine, whatever the electrolytes involved.