Effects of watering parameters in a combined seawater desalination process

Abstract

Seawater desalination experiments using patented experimental platform that could recycle cold energy released from LNG (liquefied natural gas) re-gasification process were conducted in laboratory. Combined freezing, watering and centrifugal desalination (FWCD) process was employed. The effects of the key watering parameters, including proportion, temperature and pure water or seawater, on removal efficiencies of salt and measured ions and on ice yield rate were investigated. Results showed that watering process benefits the brine-ice separation through centrifugation and therefore the ice purity can be enhanced. To ameliorate ice product purity, increasing the mass proportion of watering raw seawater is a more feasible method than watering pure water. The desalination effect of adding raw seawater would be better in summer than in winter when other parameters constant. Comparing with combined freezing, gravity-induced and centrifugal desalination (FGCD) method, FWCD is a continuous process that can accelerate the desalination duration, and more ice with the same purity can be yielded within the salt removal efficiency range of FWCD method. Whereas more energy has to be consumed using FWCD process because higher centrifugation rotation rate is also necessary to achieve the same salt removal efficiency. Whereas the total energy consumption for unit ice product is acceptable.