Title: Exergy analysis of two-pass reverse osmosis (RO) desalination with and without energy recovery turbine (ERT)

Authors: N. Eshoul; B. Agnew; M.A. Al-Weshahi; F. Latrash

Addresses: School of Mechanical and System Engineering, Newcastle University, Newcastle Upon Tyne, NE1 8ST, UK ' School of Mechanical and System Engineering, Newcastle University, Newcastle Upon Tyne, NE1 8ST, UK ' Shinas College of Technology, Alqr, P.O. Box: 77, PC: 324, Oman ' School of Mechanical and System Engineering, Newcastle University, Newcastle Upon Tyne, NE1 8ST, UK

Abstract: The paper presents the exergy analysis of an actual two-pass RO desalination system considering the seawater solution as a real mixture and not an ideal mixture. The actual 127 ton/h two-pass RO desalination was modelled using IPSEpro software and validated against operating data. The results showed that using the energy recovery turbine (ERT) reduced the seawater RO (SWRO) desalination total power consumption by 30% and specific power consumption for SWRO per m³ water from 7.2 kW/m³ to 5.0 kW/m³. In addition, the exergy efficiency of the RO desalination improved by 49% and exergy destruction was reduced by 40%. The results also showed that the rejected seawater, when the ERT was not in use, accounted for 42% of the total exergy destruction.

Keywords: exergy analysis; two-pass reverse osmosis; reverse osmosis desalination; energy recovery turbines; ERT; exergy destruction; seawater desalination; modelling; power consumption; exergy efficiency.

DOI: 10.1504/IJEX.2016.074264

International Journal of Exergy, 2016 Vol.19 No.1, pp.1 - 14

Received: 08 Aug 2014
Accepted: 17 Dec 2014
Published online: 20 Jan 2016 *

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