Membrane research for salinity gradient energy production. Final report

Technical Report · Wed Aug 16 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6749667· OSTI ID:6749667

Lonsdale, H. K.; Baker, R. W.; Lee, K. L.; Smith, K. L.

The results of an initial feasibility study of pressure retarded osmosis (PRO) as a power generation technique from various salinity gradient resources are presented. A number of flat sheet reverse osmosis membranes were evaluated including cellulose acetates, polyamide, polybenzimidazolone, and composite membranes. Reverse osmosis (RO) and direct osmosis (DO) experiments were used to predict the performance of the membranes under PRO conditions. The conclusions are: (1) concentration polarization is a major problem in PRO; (2) internal concentration polarization cannot be overcome by using brines of highly rejected salts such as magnesium sulfate; (3) useful PRO membranes do not require the ultrahigh permselectivity necessary in reverse osmosis, and a trade-off between flux and salt rejection is possible; (4) hollow fiber membranes are likely the most promising membrane geometry for two reasons: they allow control of external concentration polarization by circulation of solution on both sides of the membrane, and they are the cheapest form of membrane currently available; (5) the flux through a direct osmosis membrane using concentrated brine as the salt solution and seawater as the dilute solution is approximately half of the flux obtained when fresh water is used on the dilute side of the membrane; (6) because the operating pressures of PRO systems are lower than those used in RO, compaction of porous membranes due to hydrostatic pressure gradients is reduced; and (7) it appears that PRO is an economically viable power generation technique, provided that asymmetric (Loeb-Sourirajan-type) hollow fibers can be prepared with membrane fluxes comparable to flat sheet membranes. (WHK)

• Research Organization: Bend Research, Inc., OR (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-77ET20364
• OSTI ID: 6749667
• Report Number(s): DOE/ET/20364-T1
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140800* -- Solar Energy-- Ocean Energy Systems
ACETATES
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
AZOLES
BENZIMIDAZOLES
BRINES
CARBOXYLIC ACID SALTS
CHLORIDES
CHLORINE COMPOUNDS
COMPOSITE MATERIALS
DATA
DIFFUSION
EXPERIMENTAL DATA
FEASIBILITY STUDIES
FRESH WATER
GRAPHS
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
IMIDAZOLES
INFORMATION
MAGNESIUM COMPOUNDS
MAGNESIUM SULFATES
MATERIALS
MEMBRANES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
OSMOSIS
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PERMEABILITY
POLARIZATION
POLYAMIDES
POLYMERS
POWER PLANTS
QUANTITY RATIO
SALINITY GRADIENT POWER PLANTS
SALINITY GRADIENTS
SEAWATER
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLAR POWER PLANTS
SULFATES
SULFUR COMPOUNDS
TESTING
THEORETICAL DATA
WATER