Process Design and Economic Study of Seawater Desalination Based on the Reverse Osmosis: Case Study of Neka Power Plant

Nowadays, decreasing access to sustainable water sources has pushed the water shortage to water stress and water crisis in some cases. This phenomenon has led to more and more researchers and craftsmans’ efforts to achieve cost-effective commercial processes for a sustainable supply of water. Reverse osmosis process showed suitable potential for supplying the human’s required drinking water among all the water treatment processes. However, this process needs economic studies in macro-industrial levels. Neka power plants’ reverse osmosis desalination of seawater has been designed for production of 6,000 m3/day desalinated water. Feed water of this plant is supplied from the Caspian Sea with total dissolved solids of 15,000 mg/L and electrical conductivity of 20,000 µS/cm. Based on the results, required capital cost of this plant is $6 million and annual variable cost of $1.232 million is needed for desalination plant operation. Final fixed price of the desalinated water has been calculated $0.684 per cubic meter of desalinated water with the consideration of 20 years’ plant life cycle. Break-even point of the desalination plant has been obtained less than 6 years and less than 2 years with sales price of 1 $/m3 and 2 $/m3 of desalinated water, respectively. Results show that reverse osmosis based desalination systems are a suitable replacement for conventional freshwater sources.