METHOD AND SYSTEM FOR REDUCING ATMOSPHERIC C0 ₂ USING RENEWABLE ENERGY-POWERED DESALINATION AND IRRIGATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing of U.S. Provisional Patent Application Serial No. 62/155,138, filed on April 30, 2015, and the specification and claims thereof are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR

DEVELOPMENT

[0002] Not Applicable.

INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT

DISC

[0003] Not Applicable.

COPYRIGHTED MATERIAL

[0004] Not Applicable.

BACKGROUND OF THE INVENTION

Field of the Invention (Technical Field):

[0005] The present invention relates to methods and apparatuses employing seawater to beneficial effect. Description of Related Art:

[0006] Desalination of water is at present a very energy intensive affair.

Accordingly, in order for that technology to be employed effectively on a large-scale basis, it needs to be tied to a concomitant renewable energy resource as well as to be provided with large quantities of sea water. The present invention provides such a system.

BRIEF SUMMARY OF THE INVENTION

[0007] The present invention is of a method for desalinating seawater, comprising: pumping seawater to a coastal land region via wave-energy-driven pumps; delivering the seawater to one or more desalination systems in the land region; and operating the one or more desalination systems to create fresh water from the seawater. In the preferred embodiment, the method additionally comprises distributing the resulting fresh water onto the land region to promote growth of green plants, more preferably thereby also reducing atmospheric CO ₂ , and most preferably additionally comprising estimating the amount of CO ₂ absorbed from the atmosphere by estimating carbon content of biomass of green plants grown using the method. Operating preferably employs renewable energy, most preferably selected from wave energy, wind energy, solar energy, and geothermal energy. Pumping comprises employing one or more arrays, each array comprising one or more strings of connected pumps, preferably connected by hoses connected to mooring lines.

[0008] The invention is also of a system for desalinating seawater, comprising: wave-energy-driven pumps pumping seawater to a coastal land region; and one or more desalination systems in the land region connected to said wave-energy-driven pumps and operating to create fresh water from the seawater. In the preferred embodiment, the system additionally comprises irrigation pipes distributing the resulting fresh water onto the land region to promote growth of green plants, preferably also thereby reducing atmospheric CO ₂ . The one or more desalination systems preferably employ renewable energy, most preferably selected from wave energy, wind energy, solar energy, and geothermal energy. The system preferably additionally comprises one or more arrays, each array comprising one or more strings of connected pumps, preferably connected by hoses connected to mooring lines.

[0009] Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the

instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

[0011] Fig. 1 is a schematic diagram of a wave-energy-driven pump system of the invention providing pressurized sea water to an onshore desalination facility;

[0012] Fig. 2 is a schematic diagram of an irrigation system according to the invention with sea water provided by the system of Fig. 1 ; [0013] Fig. 3A is a global map showing coastal deserts adjacent to sources of wave energy;

[0014] Fig. 3B is a global map with aridity index;

[0015] Fig. 3C is a global map showing world population density;

[0016] Fig. 4 shows projections of CO ₂ absorbed for various possible future CO ₂ levels;

[0017] Fig. 5 is a schematic diagram of a system according to the invention with a pattern of eight arrays within one square kilometer; and

[0018] Fig. 6 is a schematic diagram of a system according to the invention placed in an illustrative coastal region near No, Peru.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention relates to a system which pumps seawater from the ocean to land, then receives the seawater in a desalination module which desalinates the seawater, and provides the resulting fresh water to irrigation devices which send the fresh water inland to be widely dispersed, whereby the entire system is located in relatively unoccupied and remote coastal regions of the world. The purpose of the irrigation method is to promote the growth of green plants where few green plants now exist. The green plants may be allowed to grow naturally from existing seed stock, without application of nutrients; ground management such as tilling or other agricultural techniques may be applied to enhance the growth of the plants. These agricultural techniques may include the provision of dissolved fertilizer into the irrigation devices, spreading fertilizer within the region, spreading seeds on the region, and other commonly used agricultural techniques.

[0020] Whether native species or introduced species, the growth of these new green plants will absorb CC from the atmosphere by the process of photosynthesis. When applied across large regions of coastal desert land, the absorbed CO ₂ may be sufficient to reduce overall levels of C0 ₂ in the atmosphere, which will help mitigate the warming of the earth due to buildup of CO ₂ and other greenhouse gases.

[0021] The seawater pumping apparatus preferably comprises an array of wave-driven seawater pumps as described in PCT/US2013/067056 "Hydraulic

Pressure Generating System". In the present invention, multiple arrays are secured within a region of the ocean, the region preferably occupying about one square kilometer, such that the arrays operate independently and generally do not interfere with each other. This arrangement is depicted in Figure 5 as a "checkerboard pattern".

[0022] The desalination module may comprise conventional containerized reverse-osmosis membrane systems such as described by RODI Systems

Corporation at its website (www.rodisystems.com); or may utilize future desalination technologies such as electrochemical mediation as described by Okeanos

Technologies, LLC at its website (www.okeanostech.com); graphene membranes as described in U.S. Patent No. 8,361 ,321 , of Lockheed Martin Corporation; or any other method for obtaining fresh water from seawater.

[0023] The desalination system can be powered by renewable energy such as electricity produced by wave energy, hydro power, solar panels, wind turbines, geothermal systems, ocean thermal energy devices, ocean salinity devices, tidal or water currents power, etc. In addition, the desalination system may incorporate energy recovery devices such as those produced by Energy Recovery, Inc. per its website (www.energyrecovery.com/px-pressure-exchanger-devices).

[0024] The irrigation system preferably comprises pipes with small holes, connected to the desalination system and then connected together in various lengths so as to distribute a relatively steady amount of fresh water across a large region. Systems such as these are exemplified by the website of Netafim Company

(www .netafim.com).

[0025] The current invention differs from various other approaches which have been proposed to reduce the greenhouse gas effects of atmospheric C02. One approach is called solar-radiation-management (SRM). A subset of SRM is to inject reflecting particles high into the atmosphere to reflect sunlight and cool the earth. Another subset of SRM is called cloud-brightening, whereby certain gaseous elements are injected into the lower atmosphere to make the tops of clouds whiter, thus reflecting more solar radiation and cooling the earth. Several approaches involve land-based projects such as planting trees, or reducing the harvesting of tropical rainforests, both of which could maintain or increase the photosynthetic absorption of C02. Spreading iron dust on the oceans has been proposed as this may increase phytoplankton, which absorb dissolved CC from the upper ocean. It is thought that less dissolved CO ₂ in the upper ocean will trigger higher rates of CO ₂ absorption by the oceans from the atmosphere, and as the phytoplankton die they sink to the bottom of the ocean (burying the absorbed CO ₂ in the deep seafloor).

[0026] These other approaches all have various deficiencies. First, is it possible to stop the method if something goes wrong? What are the side effects? Is the time frame for activation soon enough to achieve a meaningful outcome, or does the method take so long that the approach is ineffective? And, what will be the effects of stopping - will temperatures shoot upward, making the situation even worse? Who is in control? Could a rogue actor decide to implement an effort without global knowledge or approval? What is the cost, and who will pay?

[0027] The current invention addresses most of these concerns. The method can be stopped simply by selectively turning off the flow of seawater into one or more of the desalination modules, and allowing that pumped seawater to flow back into the ocean. Side effects are no different than a series of rainstorms naturally causing the desert to bloom. The time frame for activation of a single system is less than six months. The global coastal deserts which extend a total of about 10,000 linear kilometers, can be fully populated with 80,000 offshore arrays (8 per square kilometer arranged in a checkerboard pattern) within a few decades. Once fresh water is reaching these arid lands, it is quite likely to trigger plant growth each growing season, probably in successively greater amounts year by year as the plants die and their decay rejuvenates nutrients in the surface layer. Given this is a natural process, the reduction in atmospheric CO ₂ should be relatively constant once the systems are fully deployed. Immediate control can reside with those countries containing the vast coastal deserts who host these systems - Mexico, Peru, Chile, Australia, Senegal, Morocco, and South Africa - presumably earning some land rental fees to cover any excess governmental costs incurred. Overall control can be a function of international governmental groups such as the United Nations, or the Intergovernmental Panel on Climate Change (IPCC). Given the large areas involved, a rogue actor would not have access or capability to undertake this effort. Finally, the cost is believed to be modest - under $20 per ton of CO ₂ absorbed while in the startup phase, and under $5 per ton once fully deployed.

[0028] Turning to the figures, Fig. 1 is a schematic diagram of a wave-energy- driven pump system of the invention providing pressurized sea water to an onshore desalination facility. The system 10 comprises use of waves 12, strings 14 of one or more (e.g., five) buoys, seawater pumps 16, variable sea anchors 20, preferably connected to seafloor 18, tide-level adjusting mooring system 22, manifold 24, and network hose(s) 26 to onshore desalination module(s) 28.

[0029] Fig. 2 is a schematic diagram of an irrigation system according to the invention with sea water provided by the system of Fig. 1. Network hose(s) 26 provide seawater from one or more offshore wave-driven pump arrays to onshore desalination module(s) 28. Irrigation pipes 30 (e.g., drip irrigation pipes), or other water distribution systems (e.g., irrigation ditches) conduct water to fields to be irrigated with fresh water produced by the desalination module(s).

[0030] Fig. 3A is a global map showing coastal deserts adjacent to sources of wave energy, Fig. 3B is a global map with aridity index, and Fig. 3C is a global map showing world population density. Fig. 4 shows projections of CO ₂ absorbed for various possible future CO ₂ levels.

[0031] Fig. 5 is a schematic diagram of a system according to the invention with a pattern of eight arrays within one square kilometer. This larger system 32 can comprise any number of arrays 34 and concomitant hoses 26. Fig. 6 is a schematic diagram of a system according to the invention placed in an illustrative coastal region near Ho, Peru.

[0032] Note that in the specification and claims, "about" or "approximately" means within twenty percent (20%) of the numerical amount cited.

[0033] Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.