Hybrid pressure retarded osmosis–membrane distillation (PRO–MD) process for osmotic power and clean water generation

Abstract

Fueled by non-linear growths in world population and water & energy consumption, global water and energy demands have risen exponentially in tandem with exacerbated environmental issues, necessitating the exploration of alternative clean water and renewable energy resources. By integrating pressure retarded osmosis (PRO) and membrane distillation (MD), this study has demonstrated an advanced PRO−MD hybrid process for sustainable generation of osmotic power and clean water from either freshwater or real wastewater. The proposed hybrid system exhibits unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. We believe this work would provide insightful guidelines for the exploration of alternative green technologies for renewable osmotic energy and clean water production. further reduced by applying a heat exchanger in the hybrid system and using low-grade heat or 34 solar energy to heat up the feed solution. The newly developed PRO−MD hybrid process would 35 provide insightful guidelines for the exploration of alternative green technologies for renewable 36 osmotic energy and clean water production. 37

Performance analysis of reverse osmosis, membrane distillation, and pressure-retarded osmosis hybrid processes

“…In particular, a combination of pressure-retarded osmosis (PRO) and membrane distillation (MD) is thought to be a favorable candidate as a water-energy nexus process. A recent publication by Han et al [6] for instance, experimentally investigated the performance of PRO-D hybrid process through a lab-scale system.…”

Maximum power point tracking (MPPT) control of pressure retarded osmosis (PRO) salinity power plant: Development and comparison of different techniques

“…PRO also shows promising performance in other hybrid processes. In a novel PRO-MD (membrane distillation) hybrid process, the maximum power densities of 31.0 W/m 2 and 9.3 W/m 2 by the PRO using DI water and real wastewater mixing with 2M NaCl concentrate [17]. In another hybrid multi-stage vacuum MD and PRO process, maximum power density of 9.7 W/m 2 is achieved when river water is used as feed solution [18].…”

Membrane Operations for Process Intensification in Desalination

“…The osmotic pressure extracts the fresh water from dilute to the concentrated solution. The pressure generated on the high salinity solution side can be used to run a hydro turbine [27,28].For this process, several combinations of feed and draw solutions have been tested including river and seawater [29], seawater brine and wastewater retentate, freshwater and synthetic NaCl solution [30], and seawater and municipal wastewater [31].…”

“…The authors have concluded that the proposed system can bring the desalination energy demand down to 1 kWh/m 3 . In order to increase the power density of the PRO process, Han et al [30] have proposed the integration of PRO with a closed loop MD process. MD maintains a high concentration of draw solution that extracts freshwater from the The feasibility of an integrated MD-RED depends on several factors affecting the performance of individual system units.…”