Investigation of the Effects of Temperature on Net Driving Pressure and Pressure Drop in Different Configurations of the Reverse Osmosis System Using Computer Simulations

Water treatment using RO is one of the most cost-effective methods. This study investigates how temperature affects pressure drop and NDP in SWRO and BWRO units. For each membrane used in hybrid and simple single-stage configurations of the RO systems, the results showed a reduction in pressure drop and NDP at higher temperatures. Based on the simulations performed, the average pressure drop and NDP of the hybrid single-stage configuration were less than the simple single-stage design of the BWRO system. Besides, the NDP in the hybrid single-stage configuration was lower than in the simple single-stage configuration, and the value of NDP in the two configurations differed by 0.32 bar. Each membrane induced a lower pressure drop at higher temperatures and required less driving pressure. As a result, the total pressure drop of hybrid and simple two-stage configurations was lower at higher temperatures. The average driving pressure of the hybrid two-stage configuration was less than the simple two-stage configuration, and the average driving pressure differed by a minimum of 0.11 bar. At higher temperatures, each membrane induced lower pressure drops in two-stage configurations. Also, a reduction of the driving pressure in each membrane in the SWRO system was observed. According to observations, the simple single-stage configuration of the SWRO system induced higher pressure drops than the hybrid single-stage configuration. Also, the total average driving pressure in the hybrid single-stage configuration was more significant than in the simple single-stage configuration, and the two differed by 0.18 bar. However, the hybrid single-stage configuration experienced smaller total pressure drops than the simple single-stage configuration, and the two differed by a minimum of 0.06 bar. The results of this paper can be used to improve and optimize the design of RO systems based on operating temperatures.