Energy recovery by PRO in sea water desalination plant

Chapter 12 - Megaton Water System: High Salinity Pressure Retarded Osmosis

Energy recovery by pressure retarded osmosis (PRO) in SWRO–PRO integrated processes

In this study, three pressure retarded osmosis (PRO) power plants are proposed to be built on the Red Sea–Dead Sea (RSDS) water conveyance project, to generate power from the salinity gradient between two water streams at different salt concentrations. The first two proposed plants are to be built after sea water reverse osmosis (SWRO) desalination plants, where Red Sea water and the rejected brine from SWRO plants are used as feed and draw solutions, respectively. In the third proposed plant, Red Sea water and Dead Sea water will be used. Results showed that the three proposed plants are technically feasible while the third plant is the only one that is economically feasible with a 134.5 MW capacity and a 0.056 $/KWh levelized cost of electricity (LCE). The power generated from the third PRO power plant accounts for about 24.7% of the power needed for the RSDS project that can be used to power SWRO-2 in order to reduce the electricity consumption by 49.3%. If the generated power from the proposed PRO plant is sold to the Jordanian national electricity grid at the current selling price in accordance with Jordanian prices of electricity, a saving of about 21.2% can be attained. It is found that using the power generated by the current proposed plants for desalination project purposes will significantly reduce the price of desalinated water produced from SWRO desalination plants.

Chapter 11 - High-Salinity Pressure Retarded Osmosis Using Seawater Reverse Osmosis Brine

Maximize the operating profit of a SWRO-PRO integrated process for optimal water production and energy recovery

Overview of pressure-retarded osmosis (PRO) process and hybrid application to sea water reverse osmosis process

Energy recovery from two-stage SWRO plant using PRO without external freshwater feed stream: Theoretical analysis

Reverse Osmosis–Pressure Retarded Osmosis hybrid system: Modelling, simulation and optimization

Preface to the special issue on “Pressure Retarded Osmosis in Megaton Water System Project”

Power generation with salinity gradient by pressure retarded osmosis using concentrated brine from SWRO system and treated sewage as pure water

Reverse Osmosis (RO) desalination has gained wide and increasing acceptance around the world as a straightforward undertaking to alleviate the alarming water crisis. An enhanced monitoring of the quality of the water feeding in seawater RO (SWRO) plant through the application of an effective pretreatment option is one of the keys to the success of RO technology in desalination plants. Over the past 10 years, advances in ultrafiltration (UF) membrane technologies in application for water and wastewater treatment have prompted an impetus for using membrane pretreatment in seawater desalination plants. By integrating SWRO plant with UF pretreatment, the rate of membrane fouling can be significantly reduced and thus extend the life of RO membrane. With the growing importance and significant advances attained in UF pretreatment, this review presents an overview of UF pretreatment in SWRO plants. The advantages offered by UF as an alternative of pretreatment option are compared to the existing conventionally used technologies. The current progress made in the integration of SWRO with UF pretreatment is also highlighted. Finally, the recent advances pursued in UF technology is reviewed in order to provide an insight and hence path the way for the future development of this technology.

Role of pressure-retarded osmosis (PRO) in the mega-ton water project

SWRO process simulator

Operation of the RO Kinetic ® energy recovery system: Description and real experiences

A significant amount of energy stored in the form of salinity in seawater reverse osmosis (SWRO) brine can be harvested by a pressure retarded osmosis (PRO) process for power generation. The crucial performance-determining factor of the PRO process is the semi-permeable PRO membrane, which separates the SWRO brine from a lower salinity solution and sustains the salinity difference between the two solutions. However, accumulation of solutes in the support membrane, namely internal concentration polarization (ICP), significantly reduces the effective salinity difference and thus severely limits the efficiency of conventional PRO membranes. In this paper, we report the fabrication and optimization of thin-film nanofiber composite PRO (TNC-PRO) membranes with a unique support membrane structure (inter-connected, low tortuousness and highly porous properties), aiming to facilitate mixing of accumulated solutes with a dilute feed stream and overcome the ICP problem. With such low structure parameter (S) value (150 μm) nanofiber support membranes (NSMs), the optimum water permeability (A) and solute permeability (B) of the TNC-PRO membrane for power generation were determined to be 4.1 L m−2 h−1 bar−1 and 1.74 L m−2 h−1 respectively. This highly efficient TNC-PRO membrane can achieve a power density of 15.2 W m−2 and maximum energy recovery of 0.86 kW h m−3, using synthetic brackish water (80 mM NaCl, π = 3.92 bar) and seawater brine (1.06 M NaCl, π = 51.8 bar) as feed and draw solution, respectively. For a more dilute synthetic river water (0.9 mM NaCl, π = 0.045 bar) feed solution, the same membrane can achieve a higher power density of 21.3 W m−2. The main performance limiting factors in PRO application such as ICP, External Concentration Polarization (ECP) and Reverse Solute Permeation (RSP) are quantified and their values are related to A, B and S values of TNC-PRO membranes.