Pressure-retarded osmosis (PRO) is a concept for power-production. PRO pulls water into a pressurized stream, increasing the volume flow rate and enabling net power production from a turbine-pump combination. Osmotic energy is used to produce mechanical work. Our group has assessed the net power production for several configurations of PRO, and we have also examined the economic viable of PRO technologies. We have also developed effectiveness-MTU models for PRO, in an analogy to heat exchanger theory.
Our conclusions generally suggest that PRO remains far from commercial viability. In particular: performance ratings need to account for net power density; draw streams must have very high salinities, well beyond the river water/seawater pairing; and the membrane power densities need to substantially increase if the economics are to become favorable.
Selected Papers on Pressure-Retarded Osmosis (PRO)
H.W. Chung, J. Swaminathan, and J.H. Lienhard V, “Multistage pressure-retarded osmosis configurations: a unifying framework and thermodynamic analysis,” Desalination, online 28 November 2019, 476:114230, 15 February 2020. (doi link) (preprint)
H.W. Chung, L.D. Banchik, J. Swaminathan, and J.H. Lienhard V, “Economic framework for net power density and levelized cost of electricity in pressure-retarded osmosis,” Desalination, online 28 Sept. 2018, 448:13-20, 15 December 2018. (doi link) (preprint)
H.W. Chung, L.D. Banchik, J. Swaminathan, and J.H. Lienhard V, “On the present and future economic viability of stand-alone pressure-retarded osmosis,” Desalination, online 21 Jan. 2017, 408:133-144, 15 April 2017. (doi link) (preprint)
L.D. Banchik, M.H. Sharqawy, and J.H. Lienhard V, “Limits of Power Production Due to Finite Membrane Area in Pressure Retarded Osmosis,” J. Membrane Sci., 468:81-89, 15 October 2014. (doi link) (preprint)
M.H. Sharqawy, L.D. Banchik, and J.H. Lienhard V, “Effectiveness-Mass Transfer Units (ε-MTU) Model of an Ideal Pressure Retarded Osmosis Membrane Mass Exchanger,” Journal of Membrane Science, 445:211-219, 15 October 2013. (doi link) (preprint)
M.H. Sharqawy, S.M. Zubair, and J.H. Lienhard V, “Second Law Analysis of Reverse Osmosis Desalination Plants: An Alternative Design Using Pressure Retarded Osmosis,” Energy, 36(11):6617-6626, Nov. 2011 (doi link)