High-fidelity simulation and parametric analysis of static indirect freeze desalination process

Attaining water sustainability is crucial, while the failure to address challenges of the current desalination processes, i.e. high energy demand and cost negatively affects the global development goals. Freeze desalination (FD) technology has a great potential to overcome such challenges as it needs only 20% of energy required by the conventional thermal processes. FD is a crystallization-based technology where freshwater is separated from the saline water mixture in forms of ice crystals by cooling. In this work, high-fidelity numerical simulation of indirect FD process in a rectangular crystallizer is done using computational fluid dynamics (CFD) modeling of incompressible multispecies flow with solidification/melting. The model was used to perform parametric studies considering the effect of (i) initial brine salinity, (ii) freezing temperature, and (iii) initial brine temperature. Results showed that brines with lower salinities tends to provide better process performance. Lower freezing temperature will obviously provide larger ice block; however, it is associated with lower removal efficiency of salt. Similarly, decreasing the initial temperature seems to be highly affecting the growth rates and ice purity. Nevertheless, static layer indirect FD seems to be less productive when compared to other dynamic indirect freezing methods as progressive and falling film. Overall, more insight was given into the FD process using the CFD modeling in which it can be used as a prefect supporting tool for further experimental design and development.