Seawater phase chemistry and modeling for evaporation and crystallization

Seawater evaporation pathway has been discussed with chemical divide theory and phase diagram of two major five-component systems with industrial importance plotted. Equations for phase equilibrium, density, boiling point elevation, and freezing point depression have been introduced and the calculations carried out with Pitzer model of activity coefficient and osmotic coefficient for electrolyte solutions. The comparisons between the model and experimental data have been shown and the model performance demonstrated with some statistic parameters. Based on the method described in this paper, a computer program has been developed and built. It has been proved that the brine chemistry simulation can be accomplished with the program for industrial evaporation and crystallization process design. • Seawater evaporative pathways with chemical divide. • Phase equilibria/diagrams of seawater systems. • Pitzer model of electrolyte solution for phase equilibrium, density, boiling point elevation and freezing point depression. • Model performance evaluation. • Application for industrial evaporation and crystallization or ZLD (Zero liquid discharge) process design.