Hybrid RO MSF: a practical option for nuclear desalination

Abstract

Hybrid RO MSF desalination combines the advantages of the high desalting performance of distillation processes and lower energy requirement of membrane processes. It allows a better match between power and water requirements and enables better utilisation of the power generated from MSF into the RO. Hybrid RO MSF can lead to an optimised feedwater temperature of the RO plant since is possible to use cooling seawater from the reject stage of the MSF plant as feed to the RO plant. Higher feed temperature is advantageous for the RO plant since water flux of the membrane is about 2.5% higher per degree temperature rise at a fixed pressure. Various RO MSF combinations coupled with a nuclear power plant were studied. The optimum hybrid RO MSF scheme will be reviewed in order to illustrate the considerable gain of this option. The potential advantages of RO MSF hybrid desalination systems with nuclear plant will be discussed. The appropriate combinations depend on the local conditions and power/water requirements. The required power to water ratio and product water quality is among the important factors determining the particular RO MSF schemes to be used.