Osmosis powers

Osmosis and Its Applications, Fig. 4 Schematic of power generation principle for a forward osmosis power plant [9]... 

Enomoto, H., Lujitsuka, M Hasegawa, T. et al. (2010) A feasibility study of pressure-retarded osmosis power generation system based on measuring permeation volume using reverse osmosis membrane. Electrical Engineering in Japan, 173 (2), 8-20. 

FIGURE 17,21 Illustration of the principle of pressure-retarded osmosis power generation that is based on the difference in osmotic pressure between saltwater and freshwater. Although it is shown here as a stepwise process, this mode of power generation operates on a continuous basis. 

Some desalination plants combine distillation with reverse osmosis to produce both power and water. Multistage flash (MSF) processes are used to produce both power and distilled water. The combination of RO and MSF and the advantages of such a combination have been reported (111). 

Industrial Wastes. Closely related to seawater concentration is the simultaneous concentration of industrial effluents and recycle of recovered water (see Wastes, industrial). These appHcations are expected to increase as environmental restrictions increase. Examples are the concentration of blowdown from cooling towers in power plants concentration of reverse osmosis blowdown and the processing of metal treatment wastes (11) (see... 

The electrical conductivity of the water is critical to the correct operation of this type of boiler, and the precise level varies with design and power requirements. However, the conductivity is always relatively low (often specifications require a level of below 15-50 p,S/cm), so demineralized or reverse-osmosis (RO) quality FW is usually specified. 

Co-location of a power plant and a seawater reverse osmosis desalination plant allows for the cooling water from a neighbouring power plant to be blended with the waste from a desalination plant before discharge (Voutchkov 2004). In such a process, seawater is used as the cooling water for the condensers in a power plant. This water is then used as both the feed for the desahnation process, and for blending to dilute the concentrate from the desalination plant. 

Co-location is not be suitable for all desalination plants. This process only becomes feasible if the volume of cooling water discharged from the power plant is at least three to four times greater than the capacity of the desalination plant (Voutchkov 2004). Furthermore, corrosion from power plant heat exchangers may elevate the levels of metal in the feed to the desalination plant, which may then damage the reverse osmosis membrane units (Voutchkov 2004). 

K.L. Lee, R.W. Baker, and H.K. Lonsdale, "Membranes for Power Generation by Pressure-Retarded Osmosis," Journal of Membrane Science, in press. 

Fig. 8. Portion of reverse osmosis (ROl desalination plant in a Singapore power station. Capacity is 2.IXX) lons/day. (Toyobn Co., Lot., Osaka. Japan)...

Approximately one-half of the reverse osmosis systems currently installed are desalinating brackish or seawater. Another 40 % are producing ultrapure water for the electronics, pharmaceutical, and power generation industries. The remainder are used in small niche applications such as pollution control and food processing. A review of reverse osmosis applications has been done by Williams et al. [52],... 

Electrical power is the energy source for RO desalination. A reverse-osmosis desalination plant is presented schematically in Figure 10.3. Electricity is used to... 

Perhaps some idea of the power of the gas chromatography-mass spectrometry approach to the analysis of organic micropollutants can be gauged by the work of Coleman et al. [134] on mutagenic extracts of potable water. Samples of the water (1818L) were concentrated to a small volume using reverse osmosis and lyophilisation. The concentrates were then fractionated by sequential extraction with petroleum ether, diethyl... 

In a reverse osmosis unit, how would the purity of the water in the outlet tank be affected if the high-pressure pump lost power ... 

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