Keywords
Experimental
Cleaning-in-place
Specific energy consumption
Life cycle cost
How to Cite
Abstract
Fouling reduces the performance of seawater reverse osmosis (SWRO) membranes by causing blockage, which leads to increased differential pressure across the membrane vessels. Over time, this can reduce efficiency and the quality of permeate. The lifespan of an RO membrane depends on the quality of the feed water, the flux the membranes are subjected to (which is influenced by the percentage recovery), and the extent of scaling/fouling the membranes accumulate. Cleaning-in-place (CIP) is a commonly carried-out practice on RO plants to counteract fouling within the membranes. This study evaluates the financial impact of membrane fouling by comparing the effect of membrane replacement and CIP on the specific energy consumption (SEC) of a SWRO plant operated in the Maldives by using operational data collected between January 2018 and January 2024. The water production and energy consumption of the plant were used to calculate the SEC. A life cycle cost analysis was carried out to determine the optimum membrane replacement period. The breakeven point for replacing every 4 years as compared to replacing them in every 5 years is 5 years. The breakeven of 4-year-period membrane replacement against a scenario where only CIP is done is 6.08 years. It was found that the SEC improves by 0.07 kWh/m³ on average after CIP. Replacing the membrane every 4 years results in the lowest energy consumption and consequently the lowest cumulative cost over a 12-year period.
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