Investigation of different operational strategies for the variable operation of a simple reverse osmosis unit

Recent studies and projects showed that a combination of a reverse osmosis desalination plant with a wind power supply is technologically feasible if the reverse osmosis plant is operated with fluctuating and intermittent loads and thus follow the energy supply characteristic of the wind turbine. On this background the goal of this paper is to simulate the system behaviour of a simple reverse osmosis plant under changing process parameters (e.g. feed pressure, recovery or feed flow). These variations are systematized within so-called operational strategies. Therefore, four different operational strategies are analysed in detail with regard to given restrictions e.g. by the membrane system. For each of these strategies the specific energy consumption over the total usable load range is computed with the simulated hydraulic characteristics of each operational strategy. The analysis of the gathered data shows that a membrane system should be operated with constant permeate recovery under fluctuating wind power. This operational strategy provides low specific energy consumption over a broad load range. (C) 2009 Elsevier B.V. All rights reserved.