Process simulation and analysis of high‐pressure reverse osmosis (HPRO) in the treatment and utilization of desalination brine (saline wastewater)

Abstract

Reverse osmosis (RO) is nowadays considered to be the most dominant desalination technology. Nonetheless, due to osmotic pressure constraints, conventional RO cannot desalinate brine effluents (>70 g/L of total dissolved solids [TDS]). Thus, high-pressure RO (HPRO), that is, RO operating at a pressure of more than 82 bar, has recently attracted the interest of the water and wastewater industry. To this aim, a process simulation for the HPRO process was implemented and several sensitivity analyses were conducted for the first time. The results showed that by increasing the recovery rate by 0.05, energy consumption decreased by 3.5%. An increase in the feed brine temperature from 5°C to 30°C increases the permeate flow rate (up to 0.929 m3/h), the permeate concentration (up to 468 mg/L TDS), and the recovery rate (up to 0.435). A 10-bar pressure increases the permeate flow by approximately 9.8% and decreases the permeate concentration by approximately 6 mg/L TDS. Moreover, the use of an energy recovery device significantly reduces energy consumption by 26% (from 4.93-5.10 to 3.65-3.78 kWh/m3). Overall, HPRO is a promising technology for brine treatment and valorization in zero liquid discharge and minimal liquid discharge systems.