Freeze desalination is based on the solubility difference of salt, liquid water and ice. It enables the recovery of ice crystals form brine, without the addition of chemicals or fresh water to wash the ice with (Mtombeni, n.d.).
The concerns with freeze desalination are the salt content in the ice and the efficiency of vacuum pumps. These pumps are used to lower the temperature of the brine (Van der Merwe et al, 2009). The advantages include the reduction in energy demand in comparison with evaporation processes since the heat of fusion of ice (6.01 kJ/mol) is six times less than the heat of evaporation of water (40.65 kJ/mol) and the reduction in corrosion and scaling problems due to the low temperature (Nathoo, 2009; Van der Merwe et al, 2009).
HybridICE® is a freeze desalination method. This process of desalination is economically feasible in most brine treatment processes. Particularly when the secondary fluid is utilised for cooling purposed and when contaminated fluid can be used as a secondary refrigerant without the need to purchase ethylene glycol.
A significant benefit of this technology is that the cold energy that is generated can be stored, taking advantage of off-peak energy rates and incorporating the recovery of water as part of the cooling process (Mtombeni, n.d.).
