A solar-powered reverse osmosis system for high recovery of freshwater from saline groundwater


Desalination of groundwater is essential in arid regions that are remote from both seawater and freshwater resources. Desirable features of a groundwater desalination system include a high recovery ratio, operation from a sustainable energy source such as solar, and high water output per unit of energy and land. Here we propose a new system that uses a solar-Rankine cycle to drive reverse osmosis (RO). The working fluid such as steam is expanded against a power piston that actuates a pump piston which in turn pressurises the saline water thus passing it through RO membranes. A reciprocating crank mechanism is used to equalise the forces between the two pistons. The choice of batch mode in preference to continuous flow permits maximum energy recovery and minimal concentration polarisation in the vicinity of the RO membrane. This study analyses the sizing and efficiency of the crank mechanism, quantifies energy losses in the RO separation and predicts the overall performance. For example, a system using a field of linear Fresnel collectors occupying 1000 m2 of land and raising steam at 200 °C and 15.5 bar could desalinate 350 m3/day from saline water containing 5000 ppm of sodium chloride with a recovery ratio of 0.7.

Publication DOI: https://doi.org/10.1016/j.desal.2010.12.010
Divisions: College of Engineering & Physical Sciences > School of Engineering and Technology > Mechanical, Biomedical & Design
College of Engineering & Physical Sciences > Sustainable environment research group
Additional Information: © 2010 Elsevier B.V. Open access under CC BY-NC-ND license.
Uncontrolled Keywords: solar,rankine cycle,reverse osmosis,batch mode,brackish water,General Chemical Engineering,Mechanical Engineering,General Chemistry,General Materials Science,Water Science and Technology
Publication ISSN: 1873-4464
Last Modified: 19 Jul 2024 07:02
Date Deposited: 12 Dec 2011 12:56
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2011-04-15
Authors: Davies, Philip A. (ORCID Profile 0000-0003-4783-1234)

Export / Share Citation


Additional statistics for this record