An Alternative Approach to Estimate Solute Concentration: Exploiting the Information Embedded in the Solid Phase

The solute concentration in crystallization processes is generally estimated by observing properties of the liquid phase. Here, a novel method for online estimation of the change in the solute concentration caused by seeded batch crystallization or dissolution of a population of crystals in suspension is presented. The method is based on multiprojection imaging to track variations in the total solid volume of the population, thus enabling inference of the solute concentration through the mass conservation constraint. The solute concentration estimates obtained in this way are validated by using them to measure the solubilities of β l-glutamic acid and vanillin in water within certain temperature ranges and comparing them to literature data. The presented method shows promise in estimating the solute concentration reliably under circumstances where employing conventional techniques is challenging.