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-The correlation of thermodynamic properties of nonaqueous electrolyte solutions is relevant to design and operation of many chemical processes, as in fertilizer production and the pharmaceutical industry. In this work, the Q-electrolattice equation of state (EOS) is used to model vapor pressure, mean ionic activity coefficient, osmotic coefficient, and liquid density of sixteen methanol and ten ethanol solutions containing single strong 1:1 and 2:1 salts. The Q-electrolattice comprises the lattice-based Mattedi-Tavares-Castier (MTC) EOS, the Born term and the explicit MSA term. The model requires two adjustable parameters per ion, namely the ionic diameter and the solvent-ion interaction energy. Predictions of osmotic coefficient at 298.15 K and liquid density at different temperatures are also presented.

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Re´sume´-Proprie´te´s thermophysiques des solutions aqueuses de sels 1:1 avec l'e´quation d'e´tat de re´seau pour e´lectrolytes -L'e´quation d'e´tat, dite e´lectrolattice, est un mode`le qui e´tend l'e´quation d'e´tat de Mattedi-Tavares-Castier a`des syste`mes avec e´lectrolytes. Ce mode`le prend en compte l'effet de trois termes. Le premier terme est base´sur les trous dans le re´seau en conside´rant les effets de la composition locale, e´tude effectue´e dans le cadre de la the´orie ge´ne´ralise´e de Van der Waals : l'e´quation d'e´tat de Mattedi-Tavares-Castier a e´te´choisie pour ce premier terme. Les deuxie`me et troisie`me termes sont les contributions de Born et du MSA. Ils tiennent compte du chargement et du de´chargement des ions, et des interactions ioniques al ongue distance, respectivement. Le mode`le n'ayant besoin que de deux parame`tres d'interaction e´nerge´tique, il mode´lise de manie`re satisfaisante la pression de vapeur et le coefficient d'activiteí onique moyenne pour des solutions aqueuses simples contenant du LiCl, LiBr, LiI, NaCl, NaBr, NaI, KCl, KBr, KI, CsCl, CsBr, CsI, ou du RbCl. Deux me´thodes pour obtenir les parame`tres du mode`le sont pre´sente´es et mises en contraste : une me´thode spe´cifique pour le sel en question et une autre base´e sur les ions. Par conse´quent, l'objectif de ce travail est de calculer les proprie´te´s thermophysiques qui sont largement utilise´es pour la conception, l'exploitation et l'optimisation de nombreux proce´de´s industriels, parmi eux le dessalement de l'eau.Abstract -Thermodynamic Properties of 1:1 Salt Aqueous Solutions with the Electrolattice Equation of State -The electrolattice Equation of State (EOS) is a model that extends the MattediTavares-Castier EOS (MTC EOS) to systems with electrolytes. This model considers the effect of three terms. The first one is based on a lattice-hole model that considers local composition effects derived in the context of the generalized Van der Waals theory: the MTC EOS was chosen for this term. The second and the third terms are the Born and the MSA contributions, which take into account ion charging and discharging and long-range ionic interactions, respectively. Depending only on two energy interaction parameters, the model represents satisfactorily the vapor pressure and the mean ionic activity coefficient data of single aqueous solutions containing LiCl, LiBr, LiI, NaCl, NaBr, NaI, KCl, KBr, KI, CsCl, CsBr, CsI, or RbCl. Two methods are presented and contrasted: the salt-specific and the ion-specific approaches. Therefore, the aim of this work is to calculate thermodynamic properties that are extensively used to design, operate and optimize many industrial processes, including water desalination.

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-This work compares two strategies to fit parameters of equations of state in parallel computers, emphasizing solutions that require few changes to existing sequential programs. One strategy uses the conventional Nelder-Mead algorithm coupled with parallel objective function evaluation (SSPO). The other strategy uses a parallel Nelder-Mead algorithm coupled with sequential objective function evaluation (PSSO). The PSSO strategy, which executes parallel one-dimensional searches during each iteration, is simpler to implement and converged to parameter sets with objective functions smaller than those obtained by the SSPO strategy. The SSPO strategy produced speedups consistent with the number of processes used and is more suitable when many processors are available. Both strategies are potentially useful and choosing between them is a matter of convenience, depending on the problem at hand. With parallel computers increasingly available, the easy implementation and convenience of these two strategies should appeal to developers and users of thermodynamic models.

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