(373k) Progress in the Development of Membranes for Pressure Retarded Osmosis Process

Progress in the development of membranes for pressure retarded osmosis process

Haleema Saleem, Syed Javaid Zaidi

Center for Advanced Materials (CAM), Qatar University, Qatar

E-mail address: szaidi@qu.edu.qa

Abstract

Pressure retarded osmosis (PRO) has a huge possibility to develop into a viable process for converting the osmotic pressure of a salt solution into hydraulic pressure. It is an osmotically-driven membrane-based process that uses the energy of mixing between low- and high-salinity streams for producing mechanical energy. In this sustainable power generation process, water permeates across a semipermeable membrane from a feed stream of low concentration into a high concentration. Most of the proposed applications of the PRO process are established on the usage of the osmotic pressure of the brine solution obtained from the seawater reverse osmosis process. The PRO process is an effective way of brine management as it helps to dilute the brine to seawater salinity and could be directly discharged to the sea and also it produces energy at the same time. The current study analyzed the latest advances as well as utilization of this process, and possible energy that can be generated from salinity gradient sources in a multistage and single stage PRO processes. A main challenge in the PRO process is obtaining a commercially available membrane that blends the features of the reverse osmosis membrane (for withstanding higher hydraulic pressure) and forward osmosis membrane (to reduce the concentration polarization phenomenon). To address this challenge, facts regarding the commercially available PRO membranes along with the advanced lab-prepared PRO membranes are presented in the current study. The capability of the PRO process is shown by explaining the process design, salinity gradient resources, the energy required for pretreatment, the dual-stage PRO (DSPRO) process, and the PRO desalination systems. It is expected that this study could support in extensively understanding the PRO process and therefore provide significant information to simulate future research as well as development.

Keywords: Membrane, Dual-stage pressure retarded osmosis, Salinity gradient

Acknowledgement

The authors gratefully acknowledge the support of NPRP13S-0205-200263 project and the findings of the study are solely the responsibility of the author[s].