Applicability and limitation of the industrial reverse osmosis system simulators

Abstract

Industrial reverse osmosis (RO) system simulators predict the RO system operation results, and it is used for both RO plant designs and research. The performance of the simulators at various operating conditions (e.g., permeate flux, temperature, pH, and concentration of feed water) was investigated by comparing the projection and experimental results using 4-inch Seawater RO (SWRO) membrane modules. Although the differences between the experimental and projection results at a general feed water condition (25 °C, 32,000 mg/L) were acceptable (<15.3 %), they became larger up to 51.7 % with the changes in feed water temperature and concentration. Interestingly, membrane spec data provided by manufacturers were different from those projected by their simulators in most cases. This is the reason why the simulators from different manufacturers predicted different results at the same operation conditions with the same-spec membrane modules. In addition, some of the simulators did not correctly account for the effects of permeate flux or feed water pH on the salt rejection. Two limitations of the simulators found from this work are (1) membranes from different manufacturers cannot be compared; and (2) the prediction reliability tends to be lower at operation conditions farther from a general one.