GB2532250A - Power generation - Google Patents
Power generation Download PDFInfo
- Publication number
- GB2532250A GB2532250A GB1420177.6A GB201420177A GB2532250A GB 2532250 A GB2532250 A GB 2532250A GB 201420177 A GB201420177 A GB 201420177A GB 2532250 A GB2532250 A GB 2532250A
- Authority
- GB
- United Kingdom
- Prior art keywords
- chamber
- power generator
- salt
- salt solution
- electrical power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000010248 power generation Methods 0.000 title description 10
- 239000012266 salt solution Substances 0.000 claims abstract description 34
- 150000003839 salts Chemical class 0.000 claims abstract description 32
- 230000003204 osmotic effect Effects 0.000 claims abstract description 26
- 239000012528 membrane Substances 0.000 claims abstract description 19
- 239000013535 sea water Substances 0.000 claims abstract description 18
- 238000009434 installation Methods 0.000 claims abstract description 16
- 239000003990 capacitor Substances 0.000 claims abstract description 7
- 239000012530 fluid Substances 0.000 claims abstract description 6
- 239000007787 solid Substances 0.000 claims abstract description 4
- 239000000243 solution Substances 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 14
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 description 9
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 6
- 239000012267 brine Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000013505 freshwater Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 235000015598 salt intake Nutrition 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
- F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
- F03G7/005—Electro-chemical actuators; Actuators having a material for absorbing or desorbing gas, e.g. a metal hydride; Actuators using the difference in osmotic pressure between fluids; Actuators with elements stretchable when contacted with liquid rich in ions, with UV light, with a salt solution
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
- F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
- F03G7/008—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for characterised by the actuating element
- F03G7/015—Actuators using the difference in osmotic pressure between fluids
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/30—Energy from the sea, e.g. using wave energy or salinity gradient
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Analytical Chemistry (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
Abstract
An osmotic power generator 1 comprises a first chamber 2 containing a first salt solution e.g. filtered seawater, and a second chamber 3 containing a second salt solution, with a higher salinity than the first salt solution. The second chamber 3 is separated from the first chamber 2 by a semi-permeable membrane 4. An electrical power generator e.g. turbine 5 is connected to the second chamber 3 and driven by pressurized fluid from the second chamber. Solid salt from a reservoir 8 may be added to the second chamber 3 to maintain the salinity of the second solution. The system may be used to provide power to an underwater installation, e.g. for charging a battery or capacitor.
Description
Power Generation
TECHNICAL FIELD
The present invention relates to the field of power generation, and in particular to power generation by osmosis.
BACKGROUND
There are many subsea applications where electrical power is required, for example in the exploration for and production of oil/gas. In order to provide power, a remote source at the surface may be used, in which case power cables must be connected between a subsea installation and a surface facility. Such power cables are costly to install and maintain.
An alternative is to provide a local power source, such as a rechargeable battery or capacitor. In this this case, power must be generated locally, for example, by generating power from sea currents or waves. A problem with this type of power generation is that it relies on a regular and predictable source of energy to generate the power, and usually requires an expensive installation with many moving parts.
Electrical power may be generated by osmosis. This relies on the osmotic pressure difference between a source of salt water (the sea) and a source of fresh water (typically a river). A typical pressure difference is of the order of 25 bars. The pressure difference forces water through a turbine which generates electrical power. However, power generated in this way can only be generated at a river estuary, and so is not suitable for subsea installations remote from the river estuary as it would still require power cables to connect the turbine to the remote subsea installation.
SUMMARY
It is an object to provide a mechanism for generating power, and in particular a means for generating power usable by a subsea installation.
According to a first aspect, there is provided an osmotic power generator. A first chamber contains a first salt solution. A second chamber contains a second salt solution, the second salt solution having a higher salinity than the first salt solution.
The second chamber is separated from the first chamber by a semi-permeable membrane. An electrical power generator is operatively connected to the second chamber and configured to be driven by pressurized second slat solution from the second chamber.
As an option, the first salt solution is sea water. In this case, the osmotic power generator optionally further comprises a filter disposed upstream of the semipermeable membrane.
The osmotic power generator optionally comprises a salt reservoir containing solid salt and operatively connected to the second chamber, thereby allowing a salinity of the second salt solution to be maintained. As a further option, the osmotic power further comprises a flow control device between the salt reservoir and the second chamber, thereby allowing an operator to control a flow of salt into the second chamber.
As an option, the osmotic power generator further comprises a valve located between the second chamber and the electrical power generator, thereby allowing an operator to control a flow of the second salt solution to the electrical power generator.
The electrical power generator is optionally electrically connected to any of a capacitor, a rechargeable battery, a Peltier element, a condenser and a subsea installation.
As an option, the electrical power generator comprises a turbine.
According to a second aspect, there is provided a subsea installation comprising the osmotic power generator as described above in the first aspect.
According to a second aspect, there is provided a method of generating electrical power. A first chamber containing a first salt solution is provided. A second chamber containing a second salt solution is provided. The second salt solution has a higher salinity than the first salt solution, and is separated from the first chamber by a semipermeable membrane. The second fluid is allowed to flow from the second chamber and through an electrical power generator configured to generate electrical power from a pressure difference.
As an option, the first salt solution is sea water. As a further option, the method comprises the step of filtering the sea water at a location upstream of the semipermeable membrane.
The method optionally comprises adding salt from a salt reservoir to the second chamber. The flow of salt is optionally controlled from the salt reservoir to the second chamber using a flow control device.
As an option, the method further comprises using a valve located between the second chamber and the electrical power generator to control a flow of the second salt solution to the electrical power generator.
The method optionally further comprises connecting the electrical power generator to any of a capacitor, a rechargeable battery, a Peltier element, a condenser and a subsea installation.
An optional example of the electrical power generator is a turbine. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates schematically in a block diagram an exemplary osmotic power generator; and Figure 2 is a flow diagram showing exemplary steps.
DETAILED DESCRIPTION
It has been recognised that osmotic power can be generated using two liquids having different salt concentrations; unlike existing osmotic power generators, it is not necessary for one of the liquids to contain no salt at all.
Turning to Figure 1, there is illustrated an osmotic power generator 1. The osmotic power generator is provided with a first chamber 2 and a second chamber 3 separated by a semi-permeable membrane 4. The semi-permeable membrane 4 allows H2O molecules to pass through it, but does not allow Na or CI ions to pass through it.
The first chamber 2 holds sea water and the second chamber 3 holds liquid having a higher salinity than the sea water. The liquid in the second chamber is typically a saturated NaCI solution (termed brine). Sea water typically contains around 3.5 wt% NaCI, whereas brine typically contains around 26 wt% NaCI. In order to equalise the NaCI concentration across the semi-permeable membrane, H2O molecules will move from the first chamber 2 to the second chamber 3. This creates a differential pressure across the semi-permeable membrane, which can be used to drive an electrical power generator 5. An example of an electrical power generator 5 is a turbine, but it will be appreciated that any other type of device that generates a power using a pressure difference or a fluid flow caused by a pressure difference may be used. . The first chamber has an inlet 6 for sea water. The second chamber has an outlet to the electrical power generator 5, and a further outlet 7 to discharge liquid into the sea.
The operation consumes salt from the second chamber 3, and so the salinity of liquid in the second chamber 3 will reduce over time. In order to address this, the second chamber 3 is connected to a salt reservoir 8 of solid salt (NaCI) crystals in order to maintain the saturated solution in the second chamber. A valve may be provided between the second chamber 3 and the salt reservoir 8 in order to allow an operator to control the addition of salt to the second chamber 3.
The flow of liquid is from the sea (at a pressure determined by the depth of the osmotic power generator) into the first chamber 2. The liquid then flows through the semipermeable membrane into the second chamber 3. This liquid is at a higher pressure than the surrounding sea water, and so is forced through the electrical power generator to generate electrical power which can be used by a subsea installation 9 to which the electrical power generator 5 is connected. Typically, this power may be used to trickle charge a battery or capacitor at the subsea installation 9. The brine is then discharged into the sea through outlet 7.
A valve (not shown) may be provided between the second chamber 3 and the electrical power generator 5 in order to control power generation.
Note that the first chamber may simply be an inlet to the semi-permeable membrane 4, but it is important that the sea water is filtered before reaching the semi-permeable membrane 4 in order to prevent particulates in the sea water from 'blinding' the semipermeable membrane 4.
Figure 2 is a flow diagram illustrating exemplary steps. The following numbering corresponds to that of Figure 2: S1. Sea water flows into the first chamber 2.
S2. Owing to the salinity difference between the sea water and the salt solution in the second chamber, water passes from through the semi-permeable membrane 4 from the first chamber 2 to the second chamber 3. This increases the pressure in the second chamber 3.
S3. Salt solution in the second chamber is allowed to flow out of the second chamber through the electrical power generator 5.
S4. As salt solution flows out of the second chamber 3, the salinity of the salt solution in the second chamber is reduced. In order to address this, salt is added from the salt reservoir 8 to the second chamber.
S5. The electrical power generator 5 generates electricity as the pressurised salt solution flows through it and is discharged into the sea.
S6. The generated electrical power is used to power a subsea installation. There are many ways in which this can be achieved. A subsea installation may be powered directly. However, it is more controllable to use the generated electrical power to charge a battery or a capacity, or to provide power to a condenser or Peltier element.
Example:
Normal sea water, containing 3.5 w% NaCI, has an osmotic pressure of approximately bar, while saturated brine has an osmotic pressure of approximately 500 bar. A pressure difference approaching 475 bars should therefore be available for power generation.
The maximum possible power generated from fluid flowing with a pressure drop is given by the following equation: PH= Ap[Pcd* V[m Where P is power, Ap is pressure difference and V is volumetric flow rate.
The required continuous flow rate of brine to generate a power of 300 W is given by equation 2: 3 (2) V = 300Wen - = 0.0227 in 475 -105Pa s hr This leads to a salt consumption from the reservoir 8 of approximately 8.3 kg/hr. (Saturated brine at 0°C contains approximately 26 w% NaCI.) The efficiency of system and membranes is obviously less than 100%, so the flow rate must be somewhat larger to produce a power of 300 W. Note that where power generation is required for a limited time, the salt reservoir 8 may contain enough salt for the expected lifetime of operation. Alternatively, the salt reservoir 8 may be provided with an inlet to allow it to be recharged with salt when 20 required.
The concept of using an osmotic power generator 1 where the low salinity chamber contains sea water (rather than fresh water) allows local subsea power generation to be used.
It will be appreciated by the person of skill in the art that various modifications may be made to the above-described embodiments without departing from the scope of the present invention. For example, while the above description refers to power generation using a turbine, any other type of generator that generates electrical power from a fluid pressure difference may be used. (1)
Claims (17)
- CLAIMS: 1. An osmotic power generator comprising: a first chamber containing a first salt solution; a second chamber containing a second salt solution, the second salt solution having a higher salinity than the first salt solution, the second chamber being separated from the first chamber by a semi-permeable membrane; an electrical power generator operatively connected to the second chamber and configured to be driven by pressurized second slat solution from the second chamber.
- 2. The osmotic power generator according to claim 1, wherein the first salt solution is sea water.
- 3. The osmotic power generator according to claim 2, further comprising a filter disposed upstream of the semi-permeable membrane.
- 4. The osmotic power generator according to claim 1, 2 or 3, further comprising a salt reservoir containing solid salt and operatively connected to the second chamber, thereby allowing a salinity of the second salt solution to be maintained.
- 5. The osmotic power generator according to claim 4, further comprising a flow control device between the salt reservoir and the second chamber, thereby allowing an operator to control a flow of salt into the second chamber.
- 6. The osmotic power generator according to any one of claims 1 to 5, further comprising a valve located between the second chamber and the electrical power generator, thereby allowing an operator to control a flow of the second salt solution to the electrical power generator.
- 7. The osmotic power generator according to any one of claims 1 to 6, wherein the electrical power generator is electrically connected to any of a capacitor, a rechargeable battery, a Peltier element, a condenser and a subsea installation.
- 8. The osmotic power generator according to any one of claims 1 to 6, wherein the electrical power generator comprises a turbine.
- 9. A subsea installation comprising the osmotic power generator according to any one of claims 1 to 8.
- 10. A method of generating electrical power, the method comprising: providing a first chamber containing a first salt solution; providing a second chamber containing a second salt solution, the second salt solution having a higher salinity than the first salt solution, the second chamber being separated from the first chamber by a semi-permeable membrane; allowing the second fluid to flow from the second chamber and through an electrical power generator configured to generate electrical power from a pressure difference.
- 11. The method according to claim 10, wherein the first salt solution is sea water.
- 12. The method according to claim 11, further comprising filtering the sea water at a location upstream of the semi-permeable membrane.
- 13. The method according to claims 10, 11 or 12, further adding salt from a salt reservoir to the second chamber.
- 14. The method according to claim 13, further comprising controlling a flow of salt from the salt reservoir to the second chamber using a flow control device.
- 15. The method according to any one of claims 10 to 14, further comprising using a valve located between the second chamber and the electrical power generator to control a flow of the second salt solution to the electrical power generator.
- 16. The method according to any one of claims 10 to 13, further comprising connecting the electrical power generator to any of a capacitor, a rechargeable battery, a Peltier element, a condenser and a subsea installation.
- 17. The method according to any one of claims 10 to 16, wherein the electrical power generator comprises a turbine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1420177.6A GB2532250A (en) | 2014-11-13 | 2014-11-13 | Power generation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1420177.6A GB2532250A (en) | 2014-11-13 | 2014-11-13 | Power generation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201420177D0 GB201420177D0 (en) | 2014-12-31 |
| GB2532250A true GB2532250A (en) | 2016-05-18 |
Family
ID=52248292
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1420177.6A Withdrawn GB2532250A (en) | 2014-11-13 | 2014-11-13 | Power generation |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2532250A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021239701A1 (en) * | 2020-05-26 | 2021-12-02 | Saltpower Holding Aps | Brine saturator |
| WO2024028222A1 (en) * | 2022-08-02 | 2024-02-08 | Russwurm Heinz Georg | Salt power plant |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012161663A1 (en) * | 2011-05-25 | 2012-11-29 | Nanyang Technological University | A power generating device, and a method of generating power by forward osmosis |
| US20130160435A1 (en) * | 2010-05-20 | 2013-06-27 | Ohl Medio Ambiente, Inima, S.A.U. | Process for the production of hydraulic energy and production of potable water by direct osmosis |
| US20130318870A1 (en) * | 2013-08-15 | 2013-12-05 | Jae Hyun Lim | Applications of the bittern produced using the evaporation process of the floating salt farm |
| US20140110328A1 (en) * | 2011-06-08 | 2014-04-24 | Nitto Denko Corporation | Forward osmosis membrane flow system and composite semipermeable membrane for forward osmosis membrane flow system |
-
2014
- 2014-11-13 GB GB1420177.6A patent/GB2532250A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130160435A1 (en) * | 2010-05-20 | 2013-06-27 | Ohl Medio Ambiente, Inima, S.A.U. | Process for the production of hydraulic energy and production of potable water by direct osmosis |
| WO2012161663A1 (en) * | 2011-05-25 | 2012-11-29 | Nanyang Technological University | A power generating device, and a method of generating power by forward osmosis |
| US20140110328A1 (en) * | 2011-06-08 | 2014-04-24 | Nitto Denko Corporation | Forward osmosis membrane flow system and composite semipermeable membrane for forward osmosis membrane flow system |
| US20130318870A1 (en) * | 2013-08-15 | 2013-12-05 | Jae Hyun Lim | Applications of the bittern produced using the evaporation process of the floating salt farm |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021239701A1 (en) * | 2020-05-26 | 2021-12-02 | Saltpower Holding Aps | Brine saturator |
| WO2024028222A1 (en) * | 2022-08-02 | 2024-02-08 | Russwurm Heinz Georg | Salt power plant |
| DE102022119377A1 (en) | 2022-08-02 | 2024-02-08 | Georg Béla Husz | SALT POWER PLANT |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201420177D0 (en) | 2014-12-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |