A concise analytical model for the ideal reverse osmosis desalination processes

Permeate recovery is a key parameter that plays a central role in the performance assessment and optimization of reverse osmosis processes. It remains a great challenge for engineers in the field to determine the recovery conveniently and accurately from the basic parameters of a membrane system. A concise analytical model is presented here that, without the need for the empirical or fitting coefficients and tedious numerical calculation, links the recovery of a reverse osmosis process rigorously to three basic parameters: the feed water salt concentration, the characteristic of membrane process, and the driving pressure. A graphical solution method to the model is also introduced to find out the recovery effortlessly. The concise model and graphical method are demonstrated under various conditions as a powerful tool for the performance simulations and improvement of reverse osmosis processes. PRACTITIONER POINTS: A concise model is presented for permeate recovery in an ideal RO desalination system. The recovery of an RO system is analytically related to a few system parameters. A graphical solution method is introduced to find out the explicit recovery. The ideal RO model can be a powerful tool for simulation of RO processes.