Volume 5: Innovative Solutions for Energy Transitions: Part IV

Experimental and Numerical Investigation of Desalination by Indirect Directional Freezing Khadije El Kadi, Isam Janajreh, Sherien Elagroudy

Abstract

Only 20% of energy consumed by conventional thermal desalination processes is needed for a successful freeze desalination process. Freeze desalination (FD) is a freezing-melting technology where freshwater in form of ice blocks is separated by cooling from salt-water solution. Freezing in directional configuration found to be advantageous for better relocation of impurities away from ice crystals. In this work, desalination of artificial seawater using radial freezing at the side walls of cylindrical crystallizer is assessed experimentally and numerically. A 2-D axisymmetric computational fluid dynamics model of multispecies flow with solidification and melting model is utilized to simulate the experimental apparatus. Results showed a successful radial freezing where salt diffusion towards the center is observed. Removal efficiency and effective partition coefficient were investigated experimentally and numerically with a very good agreement. Nonetheless, higher efficiencies are achievable when optimum freezing temperature and stirring at ice front are present.

Keywords freeze desalination, CFD, directional freezing, indirect freeze crystallization, removal efficiency