Thermodynamic Analysis of Single and Multi-Effect Freeze Desalination

Freezing desalination technology can be used to treat hypersaline brine more. It requires less energy than conventional desalination. A refrigeration CO2 system is used for cooling required in freeze desalination (FD). The suggested CO2 system has a greater COP than traditional systems because it uses two condensers in the place of a gas cooler to chill CO2 and a low-pressure condenser to melt ice. In multi-effect freeze desalination plants, the brine of previous effect is used as feed water for next effect. Analysis was performed for one-effect freeze desalination (1EFD), two-effect freeze desalination (2EFD), and three-effect freeze desalination (3EFD) with different ice ratio fraction (F,) for each effect, and 14 configurations with the lowest specific energy consumption (SEC), and highest recovery were selected and the effects of temperature and salinity of feed water and F, are studied. Multi-effect freeze desalination is more energy efficient than single-effect freeze desalination based on a thermodynamic study of two processes. Compared to a lEFD, a 2EFD used 39 % less energy to function at a recovery of 68 %. Furthermore, the SEC of 3EFD system at the recovery of 76.11 % is 11.63 kJ/kg of product water.