Keywords: seawater reverse osmosis, large-scale reverse osmosis, cogeneration, contiguous reverse osmosis, feeds preheat, membrane manufacturers, permeability coefficient, membrane characteristics, membrane operating limits, seawater desalination
Cogenerative seawater reverse osmosis. Part 1: elements characteristics
This work is a part of an extensive study performed in the area of cogenerative seawater Reverse Osmosis (RO) design, appraisal and rehabilitation. It is concerned with large-scale contiguous seawater RO systems, focusing on the 8040-type membranes of high-flow and high-salt rejection ranging in area from 300 to 400 ft². Seventeen types of membranes are selected between large- and medium-sized spiral-wound membranes (FilmTec, Fluid Systems (Koch), Hydranautics, Osmonics, Toray, Trisep and CSM). The equations describing the above-mentioned membrane permeability coefficients are deduced; using the manufacturer-associated software for each membrane. A study of the leading element of the array shows that there are constraints that must be considered. These constraints include maximum membrane flux, maximum applied feed pressure, maximum feed flow rate, and maximum feed temperature. In order to attain a maximum membrane flux, the applied feed pressure must be lowered as the feed temperature is increased. The results from the present study (for the different operating conditions), highlighted promising membranes that could be adapted for the cogenerative contiguous membranes RO process. It should be pointed out that other studies must be carried out for the RO system designed for the aforementioned membrane to confirm these findings.