Reliable and Novel Approach Based on Thermodynamic Property Estimation of Low to High Salinity Aqueous Sodium Chloride Solutions for Water-Energy Nexus Applications

Abstract

There is a significant need for reliable and accurate thermodynamic property data of hypersaline solutions to understand the minimum heat and work of separation required and it is quite useful for large-scale desalination and water-energy nexus (WEN) applications. WEN-related technological developments are posed to dominate the scientific pursuits in the coming decade. In this regard, an understanding on the thermoacoustical parameters of hypersaline NaCl−water systems has been obtained in this study, which may lead to a better understanding of WEN. An analysis of thermodynamic properties such as free volume, intermolecular free length, isothermal compressibility, isobaric expansibility, relaxation time, and internal pressures using ultrasonic velocity has assisted us in understanding the various interactions occurring in hypersaline solutions (up to 100 g/kg). A new correlation for internal, osmotic, and vapor pressure determination has been proposed in this work. The evaluation of relaxation time showed a minimum value around a concentration range of 25−40 g/kg, which could explain the observed seawater salt concentrations at ambient temperatures. A linear variation was observed between osmotic pressure and internal pressure, which sheds light on their interdependency. A detailed analysis on the energetics of hypersaline NaCl−water solutions has also been carried out to emphasize the fact that one must work on the extraction of osmotic power from hypersaline solutions. This work presents a comprehensive framework derived from an understanding of thermoacoustical parameters of hypersaline solutions, their critical analysis, and a look into its application in osmotic power generation technologies.

Micromechanism Underlying Wetting Behavior of the Vacuum Membrane Distillation during Desalination

“…During the past decade, the membrane wetting mechanisms induced by surfactants, , organics, solvents and salt precipitation − during the MD process have been proposed. It is generally accepted that inorganic scaling or organic fouling is one of the main factors leading to membrane wetting, , and changes in membrane surface chemistry and operating conditions were also able to cause membrane wetting. , Meanwhile, it is noteworthy that several papers reported − the membrane wetting phenomenon of pure sodium chloride solution during MD; considering local oversaturation is inevitable in membrane distillation, the wetting caused by NaCl cannot be neglected. Therefore, it is necessary to further analyze the wetting processes to clarify the membrane wetting mechanism in the MD process, especially the influences inside the membrane pores.…”

Thermophysical Properties of Alkanone + Aromatic Amine Mixtures at Varying Temperatures

“…The internal pressure (P i ) has been evaluated by Eq. 1 (Marcus, 2013;Almasi, 2020b;Rehman et al, 2020) using the knowledge of two significant parameters, namely, the coefficient (Alonso et al, 2010a;Alonso et al, 2010b;Alonso et al, 2011a). (Alonso et al, 2010a;Alonso et al, 2010b;Alonso et al, 2011a).…”

“…It is a measure of cohesion and degree of interaction in liquid mixtures. presence of attractive forces between the solute and solvent molecules causes an increase in unoccupied space or volume in the liquid mixture (Rehman et al, 2020). Free volume (V f ) is evaluated using Eq 5 (Nain, 2008;Almasi, 2020a;Almasi, 2020b), and the values are recorded in Table 1.…”

“…Free volume (V f ) represents the existing free space between the molecules in the liquid, and it is a measure of cohesion and the degree of interaction in liquid mixtures (Rehman et al, 2020).…”

“…Volumetric, acoustic, and thermophysical properties of nonaqueous binary mixtures provide valuable information about molecular interactions in systems resulting from solute-solute, solvent-solvent, solute-solvent interactions, structural effects, molecular orientation, energy changes, and free volume (Hemmat et al, 2017;Shakila et al, 2020;Jóźwiak et al, 2021). Knowledge of these properties has considerable significance in theoretical and applied areas of research (Rehman et al, 2020;Ezazi et al, 2021;Li et al, 2021;Nain, 2021;Sharma et al, 2021;Wan et al, 2021). Over the past several decades, internal pressure has played a key role in the study of the thermodynamics of liquid mixtures as it provides insights into the internal structure, clustering, structure making, and breaking along with various intermolecular interactions, namely, ionic, dipole-dipole interaction, and dipole-induced dipole attraction.…”