Siddiqui, Ameen Ahmad (2020-07). Pressure Retarded Osmosis for Energy Recovery from High Salinity Waters. Master's Thesis. Thesis uri icon


  • The demand for energy is increasing every year, with more people being added to the world energy network due to global development. The global access to electricity has increased over the past two decades. The areas previously having little or no access to electricity are rapidly getting access to modes of power consumption. All this and growing world population is putting a heavy toll on already depleting conventional sources of energy. The majority of electricity worldwide is still produced using oil, gas, and coal. But with increased environmental awareness, non-conventional sources of clean energy are being rapidly developed. Osmotic power is one such non-conventional source of power. It uses the saline energy difference between two solutions to produce power. The technology employed to harness osmotic power is known as Pressure Retarded Osmosis or PRO. PRO is a membrane-based technology that uses a semi-permeable membrane to selectively allow water molecules to pass through it but prevents the exchange of solute molecules. It was developed by Sidney Loeb in the year 1973. In this research, PRO utility is experimentally determined using flat sheet membranes. The bench-scale setup was constructed and based on experimental findings on this setup, optimum condition for the efficient performance of a PRO system is predicted i.e. appropriate feed and draw solutions compositions, transmembrane pressure difference, and optimal support and spacers. The membrane selection for the experiment was determined based on the intrinsic transport characteristics A (Pure water permeability, L m?2 h?1 bar?1), B (Salt permeability, L m?2 h?1), and S (Structural parameter, microns). Of the two commercial membranes thin film-composite (TFC) and FTS cellulose tri-acetate (CTA) used in this study, the TFC membranes showed better water permeability but they cannot withstand high-pressure load and failed at 35 bar. The CTA membrane, though having lower water permeability were able to work till 55 bar of pressure. But on using the tricot spacers and modified support plate the CTA membrane produced higher water flux and maximum power density of 19 W/m2 at 30 bar of transmembrane pressure.

publication date

  • July 2020