Reducing specific energy consumption in Reverse Osmosis (RO) water desalination: An analysis from first principles

► First-principles models are developed to analyze SEC in RO desalination. ► The dimensionless models clearly reveal the coupled behavior in RO operation. ► Increasing γ, increasing stages or using an ERD reduces SEC independently. ► These three methods should be combined in RO for the best performance. ► Optimal conditions for SEC below 3 and recovery above 80% are suggested.