Process intensification of seawater reverse osmosis through enhanced train capacity and module size – Simulation on Lanzarote IV SWRO plant

Abstract

Process intensification on seawater reverse osmosis (SWRO) plant can be realized through the increase of both train capacity and module size. The investigations were conducted based on a two-staged medium-sized (capacity of 25,000 m3/day) SWRO plant, Lanzarote IV, Canary Island. Comparison between all-16-inch (first and second stages with GE Osmonics' AE-1600 and AG-1600, respectively) and mixed (only the first stage fitted with 16-inch) pressure vessels (PV) was also discussed herein. Exergy and exergoeconomic analysis was performed to calculate specific energy consumption (SEC), effergy and water costs. ROSA 9.1 (for 8-inch diameter modules) and Winflows 3.2 (for 16-inch diameter modules) were utilized to obtain energetic and technical data. The analysis revealed that the incorporation of all-16-inch modules on Lanzarote IV allowed more versatile train size design. The availability of the train was not the sole determining factor for the total cost of 16-inch PV-based configurations since the membrane capital cost only constitutes 2–3% of the total cost. In fact, the simultaneous increase in both train size and PV diameter can significantly offer operational advantages in term of technical, economical and plant footprint for a medium-size SWRO plant.