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Journal of Non-Equilibrium Thermodynamics

Founded by Keller, Jürgen U.

Editor-in-Chief: Hoffmann, Karl Heinz

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Ed. by Michaelides, Efstathios E. / Rubi, J. Miguel

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Volume 41, Issue 4


Multistage Pressure-Retarded Osmosis

Devesh Bharadwaj / Thomas M. Fyles / Henning Struchtrup
Published Online: 2016-07-12 | DOI: https://doi.org/10.1515/jnet-2016-0017


One promising sustainable energy source is the chemical potential difference between salt and freshwater. The membrane process of pressure-retarded osmosis (PRO) has been the most widely investigated means to harvest salinity gradient energy. In this report, we analyse the thermodynamic efficiency of multistage PRO systems to optimize energy recovery from a salinity gradient. We establish a unified description of the efficiencies of the component pumps (P), turbines (T), pressure exchangers (PX), and membrane modules (M) and exploit this model to determine the maximum available work with respect to the volume of the brine produced, the volume of the sea water consumed, or the volume of the freshwater that permeates the membrane. In an idealized series configuration of 1–20 modules (PMT), the three optimization conditions have significantly different intermediate operating pressures in the modules, but demonstrate that multistage systems can recover a significantly larger fraction of the available work compared to single-stage PRO. The biggest proportional advantage occurs for one to three modules in series. The available work depends upon the component efficiencies, but the proportional advantage of multistage PRO is retained. We also optimize one- and two-stage PX–MT and PMT configurations with respect to the three volume parameters, and again significantly different optimal operating conditions are found. PX–MT systems are more efficient than PMT systems, and two-stage systems have efficiency advantages that transcend assumed component efficiencies. The results indicate that overall system design with a clear focus on critical optimization parameters has the potential to significantly improve the near-term practical feasibility of PRO.

Keywords: pressure-retarded osmosis; renewable energies; pressure exchangers


  • [1] B. E. Logan and M. Elimelech, Membrane-based processes for sustainable power generation using water, Nature 488 (2012), no. 7411, 313–319.Google Scholar

  • [2] R. E. Pattle, Production of electric power by mixing fresh and salt water in the hydroelectric pile, Nature 174 (1954), no. 4431, 660–660.Google Scholar

  • [3] S. Loeb, Production of energy from concentrated brines by pressure-retarded osmosis: I. Preliminary technical and economic correlations, J. Membr. Sci. 1 (1976), 49–63.Google Scholar

  • [4] S. Loeb and R. S. Norman, Osmotic power plants, Science 189 (1975), no. 4203, 654–655.Google Scholar

  • [5] R. S. Norman, Water salination: A source of energy, Science 186 (1974), no. 4161, 350–352.Google Scholar

  • [6] A. Achilli and A. E. Childress, Pressure retarded osmosis: From the vision of Sidney Loeb to the first prototype installation – review, Desalination 261 (2010), no. 3, 205–211.Google Scholar

  • [7] J. W. Post, J. Veerman, H. V. M. Hamelers, G. J. W. Euverink, S. J. Metz, K. Nymeijer, et al., Salinity-gradient power: Evaluation of pressure-retarded osmosis and reverse electrodialysis, J. Membr. Sci. 288 (2007), no. 1–2, 218–230.Google Scholar

  • [8] F. Helfer, C. Lemckert and Y. G. Anissimov, Osmotic power with pressure retarded osmosis: Theory, performance and trends – A review, J. Membr. Sci. 453 (2014), 337–358.Google Scholar

  • [9] K. L. Lee, R. W. Baker and H. K. Lonsdale, Membranes for power generation by pressure-retarded osmosis, J. Membr. Sci. 8 (1981), no. 2, 141–171.Google Scholar

  • [10] K. Gerstandt, K. V. Peinemann, S. E. Skilhagen, T. Thorsen and T. Holt, Membrane processes in energy supply for an osmotic power plant, Desalination 224 (2008), no. 1–3, 64–70.Google Scholar

  • [11] A. P. Straub, A. Deshmukh and M. Elimelech, Pressure-retarded osmosis for power generation from salinity gradients: Is it viable?, Energy Environ. Sci. 9 (2016), 31.Web of ScienceGoogle Scholar

  • [12] S. Lin, A. P. Straub and M. Elimelech, Thermodynamic limits of extractable energy by pressure retarded osmosis, Energy Environ. Sci. 7 (2014), no. 8, 2706–2714.Google Scholar

  • [13] K. K. Reimund, J. R. McCutcheon and A. D. Wilson, Thermodynamic analysis of energy density in pressure retarded osmosis: The impact of solution volumes and costs, J. Membr. Sci. 487 (2015), 240.Google Scholar

  • [14] S. Loeb, Large-scale power production by pressure-retarded osmosis, using river water and sea water passing through spiral modules, Desalination 143 (2002), no. 2, 115–122.Google Scholar

  • [15] J. Kim, J. Lee and J. H. Kim, Overview of pressure-retarded osmosis (PRO) process and hybrid application to sea water reverse osmosis process, Desalin. Water Treat. 43 (2012), no. 1–3, 193–200.Google Scholar

  • [16] C. F. Wan and T. S. Chung, Osmotic power generation by pressure retarded osmosis using seawater brine as the draw solution and wastewater brine as the feed, J. Membr. Sci. 479 (2015), 148–158.Google Scholar

  • [17] K. Saito, M. Irie, S. Zaitsu, H. Sakai, H. Hayashi and A. Tanioka, Power generation with salinity gradient by pressure retarded osmosis using concentrated brine from SWRO system and treated sewage as pure water, Desalin. Water Treat. 41 (2012), no. 1–3, 114–121.Google Scholar

  • [18] R. L. McGinnis, J. R. McCutcheon and M. Elimelech, A novel ammonia–carbon dioxide osmotic heat engine for power generation, J. Membr. Sci. 305 (2007), no. 1–2, 13–19.Google Scholar

  • [19] S. Lin, N. Y. Yip, T. Y. Cath, C. O. Osuji and M. Elimelech, Hybrid pressure retarded osmosis–membrane distillation system for power generation from low-grade heat: Thermodynamic analysis and energy efficiency, Environ. Sci. Technol. 48 (2014), no. 9, 5306–5313.Google Scholar

  • [20] G. Han, J. Zuo, C. F. Wan and T. S. Chung, Hybrid pressure retarded osmosis-membrane distillation (PRO-MD) process for osmotic power and clean water generation, Environ. Sci. Water Res. Technol. 1 (2015), 507–515.Google Scholar

  • [21] G. Han, Q. C. Ge and T. S. Chung, Conceptual demonstration of novel closed-loop pressure retarded osmosis process for sustainable osmotic energy generation, Appl. Energy 132 (2014), 383–393.Google Scholar

  • [22] M. F. Naguib, J. Maisonneuve, C. B. Laflamme and P. Pillay, Modeling pressure-retarded osmotic power in commercial length membranes, Renew. Energy 76 (2015), 619.Google Scholar

  • [23] W. He, Y. Wang and M. H. Shaheed, Enhanced energy generation and membrane performance by two-stage pressure retarded osmosis (PRO), Desalination 359 (2015), 186–199.Web of ScienceGoogle Scholar

  • [24] A. P. Straub, S. Lin and M. Elimelech, Module-scale analysis of pressure retarded osmosis: Performance limitations and implications for full-scale operation, Environ. Sci. Technol. 48 (2014), no. 20, 12435–12444.Google Scholar

  • [25] W. He, Y. Wang and M. H. Shaheed, Energy and thermodynamic analysis of power generation using a natural salinity gradient based pressure retarded osmosis process, Desalination 350 (2014), 86–94.Google Scholar

  • [26] L. D. Banchik, M. H. Sharqawy and J. H. Lienhard, Limits of power production Due To finite membrane area in pressure retarded osmosis, J. Membr. Sci. 468 (2014), 81.Google Scholar

  • [27] N. Y. Yip and M. Elimelech, Thermodynamic and energy efficiency analysis of power generation from natural salinity gradients by pressure retarded osmosis, Environ. Sci. Technol. 46 (2012), no. 9, 5230–5239.Google Scholar

  • [28] A. Seppälä and M. J. Lampinen, Thermodynamic optimizing of pressure-retarded osmosis power generation systems, J. Membr. Sci. 161 (1999), no. 1–2, 115–138.Google Scholar

  • [29] H. Struchtrup, Thermodynamics and Energy Conversion, Springer-Verlag, Heidelberg, 2014.Google Scholar

  • [30] E. Michaelides, Entropy production and optimization of geothermal power plants, J. Non-Eq. Thermodyn. 37 (2012), no. 3, 233–246.Google Scholar

  • [31] K. Wagner and K. H. Hoffmann, Endoreversible modeling of a PEM fuel cell, J. Non-Eq. Thermodyn. 40 (2015), no. 4, 283–294.Google Scholar

  • [32] P. Geisler, W. Krumm and T. A. Peters, Reduction of the energy demand for seawater RO with the pressure exchange system PES, Desalination 135 (2001), no. 1–3, 205–210.Google Scholar

  • [33] Y. Du, L. Xie, Y. Wang, Y. Xu and S. Wang, Optimization of reverse osmosis networks with spiral-wound modules, Ind. Eng. Chem. Res. 51 (2012), no. 36, 11764–11777.Google Scholar

  • [34] G. Migliorini and E. Luzzo, Seawater reverse osmosis plant using the pressure exchanger for energy recovery: A calculation model, Desalination 165 (2004), 289–298.Google Scholar

  • [35] V. G. Gude, Energy consumption and recovery in reverse osmosis, Desalin. Water Treat. 36 (2011), no. 1–3, 239–260.Google Scholar

  • [36] Personal Communication, Rodney B. Clemente, VP, Technical Service & Aftermarket, Energy Recovery PX Device.

  • [37] A. F. Mills, Heat Transfer, 2nd ed., Prentice Hall, Boston, 1998.Google Scholar

  • [38] C. F. Wan and T. S. Chung, Energy recovery by pressure retarded osmosis (PRO) in SWRO–PRO integrated processes, Appl. Energy 162 (2016), 687–698.Google Scholar

About the article

Received: 2016-03-07

Revised: 2016-05-18

Accepted: 2016-05-27

Published Online: 2016-07-12

Published in Print: 2016-10-01

This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) grants DG 1113 (TMF) and DG 03679 (HS).

Citation Information: Journal of Non-Equilibrium Thermodynamics, Volume 41, Issue 4, Pages 327–347, ISSN (Online) 1437-4358, ISSN (Print) 0340-0204, DOI: https://doi.org/10.1515/jnet-2016-0017.

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