Desalination at low temperatures and low pressures

A low-temperature phase-change desalination process configuration is presented in this study. This configuration enables saline water to be evaporated at near-ambient temperatures under near-vacuum level pressures created by the barometric head without any mechanical energy input. Thermodynamic advantages and benefits of low-temperature phase-change desalination are discussed and results from a prototype test system are presented to demonstrate the feasibility of the proposed configuration. Results of this study show that a freshwater production rate of 0.25 kg/h (6 L/d) can be sustained at evaporation temperatures as low as 40 degrees C. These results suggest that this process has the potential to be driven by low-grade heat sources such as waste process heat or solar collectors at temperatures as low as 50 degrees C.