Kinetics of Sodium Chloride Dissolution in Condensates Containing Ammonia and Ammonium Carbonates

Abstract

The kinetics of sodium chloride dissolution under the conditions of gravity deposition in condensates of soda production gas cooling apparatus containing ammonia and ammonium carbonates was studied. The method for calculating the dissolution rate is proposed based on measuring the deposition time of dissolving salt crystals at two points. The method is based on a mathematical model characterizing the change in the particle deposition rate in the dissolution process and taking into account the value of the dissolution rate coefficient. The impact of the temperature and solvent composition, as well as the crystal shape in the solute on the dissolution rate was investigated. It was found out that, with an increase in temperature by 10 °C, the dissolution increases 1.3 times, which indicates that the process is limited by the solute diffusion from the surface of a solid particle into the bulk of the liquid. In addition, it was determined that the dissolution rate coefficient decreases with an increase in the sodium chlorides concentration and the carbonation rate of the solution and increases with increasing ammonia concentration. Testifying the impact of the salt crystal shape on the kinetics of its dissolution showed that it is not crucial within the limits of the experiment accuracy. Using the methodology of experiment planning and regression analysis, an equation was obtained for predicting the dissolution rate of sodium chloride depending on the temperature and composition of the solution.