WO2021229585A1

WO2021229585A1 - System and method to replenish a natural salt waterbody

Info

Publication number: WO2021229585A1
Application number: PCT/IL2021/050563
Authority: WO
Inventors: Moshe Gewertz
Original assignee: Fisher Shmuel Holdings Ltd
Priority date: 2020-05-14
Filing date: 2021-05-14
Publication date: 2021-11-18
Also published as: IL274695B; IL274695A

Abstract

A system (100) for replenishing a salt waterbody (102) with salinity greater than seawater (101) while substantially retaining its chemical composition is disclosed. The salt waterbody (102) is at a level below sea level. The system includes a forward osmosis (FO) membrane device (10) in proximity to the salt waterbody (102), a first pipeline (152) channeling the seawater with gravitational flow to a feed side (10a) of the FO membrane device and a second pipeline (154) channeling brine on a feed side (10a) back to the sea (101) in a direction against gravity. A first pump assists overcoming friction of flow in the second pipeline (154). A second circulation pump (120) circulates water from the salt waterbody (102) to a draw side (10b) of said FO membrane device (10). An outlet (156) from the draw side expels the generated flow of treated seawater into the salt waterbody (102).

Description

SYSTEM AND METHOD TO REPLENISH A NATURAL SALT WATERBODY

RELATED APPLICATION/S

This application claims the benefit of priority of Israel Patent Application No. 274695 filed on 14 May 2020, the contents of which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to replenishing natural salt waterbodies and, more particularly, but not exclusively, to a system and method to replenish the Dead Sea while substantially retaining its chemical composition.

The Dead Sea is an example waterbody that is in recession. The water level in the Dead Sea is shrinking at a rate of more than one meter per year, and its surface area has shrunk by about 30% in the last 20 years. This is largely due to the diversion of over 90% of the water of the Jordan River to provide the much needed water for crops and drinking. The decline of the Dead Sea level creates significant environmental problems, including sink holes and receding sea shores.

One known proposal called the Red Sea-Dead Sea Conveyance is to direct water with a high concentration of salts resulting from the desalination process (reject brine) to stabilize the Dead Seawater level, and generate electricity to support the energy needs of the project. For this purpose a channel running between the Red Sea and the Dead Sea is proposed to be built.

An environmental group EcoPeace Middle East have raised opposition to this project and have stated the transfer of mass volumes of water from one sea to another can bear drastic consequences on the unique natural characteristics of each of the two seas. According to EcoPeace Middle East mixing Dead Sea water with Red Sea water or brines created from the process of desalinating Red Sea water may damage the unique natural systems of the Dead Sea. The damage to the Dead Sea may include changes in water salinity, massive formation of gypsum, formation of volatile toxic compounds, change in water evaporation rates, changes in the composition of bacteria and algae which inhabit the sea surface, chemical changes in the rocks which surround the water, and loss of unique health benefits that account for much of the tourist attraction to the Dead Sea area.

Instead EcoPeace Middle East has proposed to replenish the Dead Sea with manufactured water (desalination and/or treated wastewater) together with additional natural water (from the Sea of Galilee and Yarmouk Basin). Economic feasibility related to investment cost, operation cost as well as energy consumption required for such a large scale project is a significant concern. US Patent Publication Application No. 20090250398 entitled “Seawater desalination system and method,” the contents of which are incorporated by reference herein, describes a desalination system that includes a submersible module defining a water-receiving interior and including openings leading from the interior to an exterior, reverse osmosis (RO) membranes arranged in each opening such that the RO membrane is exposed to seawater when the module is submersed, a pump arranged in connection with the interior of module, and a movement system for adjusting the vertical depth at which the module is submersed. The movement system can move the module in vertical and horizontal directions, in any predetermined pattern, or in vertical- horizontal planes defined by the movement system from one location to another location to prevent an elevated salt concentration in an area adjacent the RO membranes and to thereby maintain the osmotic pressure of the seawater in the area adjacent the RO membranes low.

US Patent Publication Application No. 20170232392 entitled “Systems and methods for offshore desalination and/or oil recovery,” the contents of which are incorporated by reference herein, describes a separation system that includes forward osmosis (FO) membranes for offshore desalination and sulfate removal. The system uses submerged FO elements (e.g. operating underwater in the ocean). The system uses FO elements in combination with high-pressure reverse osmosis (RO) elements and processes. The system uses FO elements in combination with membrane distillation elements and processes. The system creates a suction and pressurized flow from a submerged FO membrane process to a reverse osmosis system on a platform, ship, or other offshore or "along shore" structure. The product water is used for enhanced oil recovery.

SUMMARY OF THE INVENTION

According to an aspect of some embodiments of the present invention there is provided a system and method to replenish a natural salt waterbody in recession. In some example embodiments, the salt waterbody is below sea level. In some example embodiments, the natural salt waterbody is the Dead Sea. According to some example embodiments, the method includes extracting water from a sea(other than the salt waterbody), treating the water, transferring the treated water into the natural salt waterbody and recycling brine accumulated from the treating process back into the same sea or other sea body. Energy for operating the system may be harnessed from gravitational flow due to a difference in height between the waterbody in recession (a hydrostatic pressure gradient) and the sea and from an osmosis pressure gradient across one or more FO membrane devices due to the difference in salinity to power operation of the system. In some example embodiments flow of the brine accumulated at a level of the salt waterbody back to the sea based on the use of a pump to overcome friction in the pipeline or based on exchange flow with a pressure exchanger. In some example embodiments, a first pipeline, e.g. an inlet directing seawater toward the salt waterbody and a second pipeline, e.g. an outlet directing the brine accumulated back to the sea are interconnected vessels and the pump is only required to overcome friction of flow through the pipelines. According to some example embodiments, the system may be at least partially self-powered. Optionally, external power may be used to start-up operation of the system and once the system is up and running its operation is at least partially and/or substantially self-powered.

According to an aspect of some example embodiments, the system may be alternatively applied for generating energy for a grid. In some example embodiments, the system includes one or more bypass pipes that are selectively controlled to alternate between directing flow to produce manufactured water and directing flow to produce energy for a grid.

According to an aspect of some example embodiments there is provided a system for replenishing a salt waterbody, the system comprising: a first forward osmosis (FO) membrane device configured to establish an osmotic pressure gradient based on salt waterbody water received on a draw side and seawater from the sea received on a feed side, wherein the salt waterbody water has a salinity level that is higher than that of the seawater and wherein the osmotic pressure gradient generates flow across the first FO membrane device; a first pump configured to circulate the salt waterbody water on the draw side; a first pipeline configured to channel the seawater from the sea to the feed side; a second pipeline configured to recycle brine on the feed side back to the sea; and a first power generator configured to harness energy from a flow generated from at least one of the osmotic pressure gradient and flow through the first pipeline to power assist operation of the system.

Optionally, the salt waterbody is below sea level and wherein the first power generator is configured to harness energy based on a drop in height of the seawater in the first pipeline.

Optionally, the salt waterbody is the Dead Sea.

Optionally, the sea is at least one of the Mediterranean Sea and the Red Sea.

Optionally, the first FO membrane device is at a level of the salt waterbody.

Optionally, the first pump is at least partially powered with power generated with the first power generator.

Optionally, the first pipeline and the second pipeline are communicating vessels that are fluidly connected at the feed side of first FO membrane device.

Optionally, the system comprises at least one bypass pipeline configured to bypass flow of the seawater to the first FO membrane device and instead direct the flow to the first power generator; and a bypass valve configured to selectively control flow through the at least one bypass pipeline.

Optionally, the at least one bypass pipeline includes a first bypass pipeline configured to establish bypass flow from the sea through the first pipeline to the first power generator and a second bypass pipeline configured to establish bypass flow from the sea through the second pipeline to the first power generator.

Optionally, the system comprises a second FO membrane device configured to establish an osmotic pressure gradient based on the brine from the second pipeline received on a draw side of the second FO membrane device and seawater from the sea received on a feed side of the second FO membrane device, wherein the osmotic pressure gradient generates flow across the second FO membrane device; and a second power generator configured to harness energy of the flow generated across the second FO membrane device, wherein the second FO membrane device is positioned at sea level of the sea.

Optionally, the system comprises a hydraulic accumulator in fluid communication with the second power generator.

Optionally, the system comprises a desalination station configured to produce manufactured water from the seawater.

Optionally, the system comprises a third power generator positioned upstream from the first FO membrane device and configured to harness energy of flow through the first pipeline.

Optionally, the system comprises a pressure exchanger configured to drive flow through the second pipeline based on flow generated across the first FO membrane device.

Optionally, the first pipeline is in fluid communication with a first sea and the second pipeline is in fluid communication with a second sea that is other than the first sea.

Optionally, the first power generator is a turbine generator.

According to an aspect of some other example embodiments there is provided another system for replenishing a salt waterbody, the system comprising: a first forward osmosis (FO) membrane device positioned in proximity to a sea and configured to establish an osmotic pressure gradient based on salt waterbody water received on a draw side and seawater from the sea received on a feed side, wherein the salt waterbody water has a salinity level that is higher than that of the seawater and wherein the osmotic pressure gradient generates flow across the first FO membrane device; a first pipeline configured to channel the salt waterbody water to the draw side of the first FO membrane device; a first pump configured to drive the flow of the salt waterbody water through the first pipeline; a second pipeline configured to channel diluted salt waterbody water from the draw side back to the salt waterbody; and a first power generator configured to harness energy from flow generated from at least one of the osmotic pressure gradient and flow through the second pipeline to power assist operation of the system.

Optionally in this other system, the salt waterbody is below sea level and wherein the first power generator is configured to harness energy based on a drop in height of the seawater in the second pipeline.

Optionally in this other system, the salt waterbody is the Dead Sea.

Optionally in this other system, the sea is at least one of the Mediterranean Sea and the Red

Sea.

Optionally in this other system, the first power generator is configured to at least partially actuate operation of the first pump.

Optionally in this other system, the system comprises a hydraulic accumulator in fluid communication with the first power generator.

Optionally in this other system, the system comprises a second FO membrane device configured to establish an osmotic pressure gradient based on brine from the feed side of the first FO membrane device channeled to the draw side of the second FO membrane device and seawater from the sea received on a feed side of the second FO membrane device, wherein the osmotic pressure gradient generates flow across the second FO membrane device; and a second power generator configured to harness energy of the flow generated across the second FO membrane device, wherein the second FO membrane device is positioned at sea level of the sea.

Optionally in this other system, the first power generator is at a level of the sea and is configured to harness energy from flow generated from at least one of the osmotic pressure gradient across the first FO membrane device and further comprising a third power generator at a level of the salt waterbody, wherein the third power generator is configured to harness energy from flow through the second pipeline.

Optionally in this other system, the first power generator is a turbine generator.

According to an aspect of some example embodiments there is provided a method for replenishing a salt waterbody below sea level, the method comprising: channeling seawater from sea level of a sea to a level of salt waterbody through a first pipeline, wherein the salt waterbody water has a salinity level that is higher than that of the seawater; directing the seawater to a feed side of a first forward osmosis FO membrane device; directing water from the salt waterbody to a draw side of the FO membrane device; drawing treated seawater across the FO membrane device based on an osmotic pressure gradient between the seawater and the water from the salt waterbody; directing the salt waterbody water that is diluted with the treated seawater to the salt waterbody; recycling brine formed with the first FO membrane device back to the sea; and harnessing energy of flow with a power generator based on at least one of a drop in height of the seawater in the first pipeline and the osmotic pressure gradient across the first FO membrane device.

Optionally in this method, the salt waterbody is below sea level and the generator is configured to harness energy based on a drop in height of the seawater the first pipeline.

Optionally in this method, the salt waterbody is the Dead Sea.

Optionally in this method, the sea is at least one of the Mediterranean Sea and the Red Sea.

Optionally in this method, the first FO membrane device is positioned at a level of the salt waterbody.

Optionally in this method, comprising pumping water from the salt waterbody to the draw side of the first FO membrane device, wherein the pumping is at least partially powered with the electricity generated.

Optionally in this method, flow of the brine to the sea is actuated based on a principle of communicating vessels.

Optionally, the method comprises selectively bypassing flow of the seawater to the first FO membrane device and instead directing the flow to a first power generator.

Optionally in this method, the recycling of the brine is based on diluting the brine with a second FO membrane device, the second FO membrane device in fluid contact with seawater from the sea on the feed side.

Optionally, the method comprises harnessing energy from pressurized flow of the brine that is diluted.

Optionally, the method comprises producing manufactured water from the seawater and powering assisting the desalination from the energy harnessed.

Optionally, the method comprises boosting flow from the salt waterbody to the sea with a pressure exchanger.

Optionally in this method, the seawater in the first pipeline is channeled from a first sea and the brine is recycled to a second sea that is other than the first sea.

Optionally, the method comprises channeling water from the salt waterbody to sea level; and wherein flow through the first pipeline is configured to direct the water from the salt waterbody diluted with treated seawater back to the salt waterbody.

Optionally in this method, the first FO membrane device is at sea level.

Optionally in this method, the electricity generated is configured to at least partially actuate flow of the water from the salt waterbody to sea level.

Optionally, the method comprises harnessing energy at sea level from pressurized flow of the water from the salt waterbody diluted with treated seawater from the first FO membrane device. Optionally, the method comprises diluting brine formed in the first FO membrane device with a second FO membrane device and directing the diluted brine to the sea.

Optionally, the method comprises harnessing energy from pressurized flow of the diluted brine with a turbine generator.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is a simplified diagram of an example system to replenish a waterbody in accordance with some example embodiments;

FIG. 2 is a simplified diagram of the example system of FIG. 1 including additional bypass pipelines in accordance with some example embodiments;

FIG. 3 is a simplified diagram of an example system to replenish a waterbody, the system harnessing energy both at sea level and at a level of the waterbody in accordance with some example embodiments;

FIG. 4 is a simplified diagram of an example system to replenish a waterbody, the system including a desalination station in accordance with some example embodiments;

FIG. 5 is a simplified diagram of a system including a desalination station and bypass pipelines in accordance with some example embodiments;

FIG. 6 is a simplified diagram another example system to replenish a waterbody, the system including a desalination station in accordance with some example embodiments; FIG. 7 is a simplified diagram of an example system to replenish a waterbody, the system including a pump to actuate flow from the waterbody to sea level, in accordance with some example embodiments;

FIG. 8 is a simplified diagram of an example system to replenish a waterbody, the system in fluid communication with two different sea bodies, in accordance with some example embodiments;

FIG. 9 is a simplified diagram of an example system to replenish a waterbody with seawater desalinated at sea level in accordance with some example embodiments; and

FIG. 10 showing a diagram of an example system for replenishing a body of water where the transfer of water between the waterbody and sea is performed at sea level in accordance with some example embodiments.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to replenishing natural salt waterbodies in recession and, more particularly, but not exclusively, to a system and method to replenish the Dead Sea.

The treating process for treating seawater as described herein includes a process that removes at least a portion of the minerals in seawater. The treating process may provide for example, water with a lower salinity than seawater, saline, brackish water or fresh water, e.g. manufactured water. Optionally, the treating process generates water with a salinity that is at least 90% less than the salinity of the seawater. Treated water as described herein refers to water obtained from the treating process.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

According to some example embodiments, the system is operated with at least one first pipeline directing water from a sea at sea level to a waterbody below sea level, at least one second pipeline directing water from the waterbody below sea level to the sea and at least one FO membrane device configured to extract treated water from the sea and replenish the waterbody below sea level with the treated water.

As used herein an FO membrane device is a device that is configured to perform a FO process. Optionally and preferably the FO membrane device includes an FO membrane, a housing as well as accompanying equipment, e.g. filters, sensors, pumps, valves and dedicated controller configured to actuate and control the FO process.

According to some example embodiments, the system is operated with two forward osmosis (FO) membrane devices. The first FO membrane device provides for extracting treated water from the sea and is optionally positioned at the level of the natural waterbody to be replenished. The second FO membrane device may be positioned at a level of the sea and may provide for recycling the collected brine back to the sea while harnessing flow generated due to the difference in salinity between the brine and seawater. According to some example embodiments, the system includes a power generator, e.g. a turbine generator in association with one or more of the first and second FO membrane devices to harness energy from the generated flow through the membranes. Optionally, a hydraulic accumulator is included in association with the turbine generator to store energy and optionally smooth pulsating flow through the turbine generator.

According to some example embodiments, one or more a pressure exchangers are included in the system to actuate flow in a direction against gravity, e.g. from the level of the waterbody to the level of the sea. Optionally, the system includes one or more pumps to assist in actuating flow in a direction against gravity. In some example embodiments, the system additionally includes a reverse osmosis (RO) membrane device configured to generate manufactured water, e.g. for drinking, agriculture and/or industry with a portion of the seawater flowing through the system.

As used herein an RO membrane device is a device that is configured to perform RO process. Optionally and preferably the RO membrane device includes an RO membrane, a housing as well as accompanying equipment, e.g. filters, sensors, pumps, valves and dedicated controller configured to actuate and control the RO process.

According to some example embodiments, the flow through system may be actuated with little energy expenditure from an external power source, e.g. the flow may be partially and/or substantially self-powered.

According to some example embodiments, the system includes one or more pipelines that selectively bypass a FO membrane device and instead direct the flow to a turbine generator to generate electricity for a grid.

Reference is now made to FIG. 1 showing a simplified diagram of an example system to replenish a waterbody in accordance with some example embodiments. According to some example embodiments, a system 100 is configured to replenish a salt waterbody 102 with treated water extracted from a sea 101. System 100 may replenish a salt waterbody 102 that is below sea level and has a salinity greater than that of sea 101. In some example embodiments, waterbody 102 is the Dead Sea and sea 101 is one of the Mediterranean Sea or the Red Sea. According to some example embodiments, water from sea 101 is channeled through a seawater pipeline toward a feed side 10a of FO membrane device 10 that is at or near a height of waterbody 102 and in fluid communication with waterbody 102. How through pipeline 152 is free flow driven by gravity. The higher salinity water from waterbody 102 provides the draw solution for FO membrane device 10 based on which treated water from sea 101, the feed solution, is extracted through FO membrane device 10 and used to replenish waterbody 102. Draw solution may be directed from waterbody 102 to FO membrane device 10 via a pipeline 151. In some examples, system 100 includes a pump 120 that actively pumps water from waterbody 102 toward FO membrane device 10. Optionally, pump 120 helps maintain a steady osmotic pressure gradient across FO membrane device 10. Operation, pump 120 may be controlled to selectively control flow rate of the feed solution generated with FO membrane device 10.

According to some example embodiments, flow across FO membrane device 10 is driven by the osmotic pressure gradient across FO membrane device 10 as well as by the hydraulic gradient due to a height Ή’ at which water from sea 101 is dropped through water line 152 and directed to FO membrane device 10 at or near a level of waterbody 102. The flow across FO membrane device 10 is pressurized flow of treated water. According to some example embodiments, the flow of treated water dilutes the draw solution directed toward FO membrane device 10 and the diluted draw solution is discharged to replenish waterbody 102.

According to some example embodiments, energy from the generated flow of across FO membrane device 10 is harnessed prior to discharging the diluted draw solution through pipeline 157 to waterbody 102. In some example embodiments, a pipeline 156 directs diluted draw solution from FO membrane device 10 to a power generator, e.g. turbine generator 110 to harness energy from the flow. Optionally, electricity generated by turbine generator 110 is applied to power operation of system 100. For example, pump 120 may be powered and/or may be power assisted with turbine generator 110.

According to some example embodiments, a pipeline 154 directs brine, e.g. concentrated seawater collected from the feed side of FO membrane device 10 back to sea 101. According to some example embodiments, flow through pipeline 154 in a direction against gravity may be driven based on the principle of communicating vessels. The present inventors have found that pipeline 152, pipeline 154 and the feed side 10a of FO membrane device 10 constitute a system of communicating vessels with each of pipelines 152 and 154 being the vessels and the feed side 10a of FO membrane device 10 being the base. Based on the principle of communicating vessels, seawater in pipeline 154 will strive to maintain a same height as the seawater in pipeline 152. Optionally, an outlet 113 of pipeline 154 is defined to be at a same height or lower than an inlet 112 of pipeline 152. Based on the principle of communicating vessels, seawater in pipeline 154 is at a same height as seawater in pipeline 152. Flow of seawater out from outlet 113 is pump assisted as needed to overcome friction of flow in the pipes.

According to some example embodiments, the flow through system 100 may continue with reduced energy expenditure from an external power source, e.g. the flow may be partially and/or substantially self-powered due to harnessing of power produced by system 100. One or more valves 160 may provide for shutting down and starting up operation of system 100. Optionally, one or more valves 160 are partially opened to control the rate at which treated water flow is expelled through pipeline 157 into waterbody 102. Optionally, a controller 800 controls operation of FO membrane device 10, turbine generator 110, valves 160 and pump 120.

In some example embodiments, waterbody 102 is the Dead Sea and sea 101 is the Mediterranean Sea or the Red Sea. In these embodiments, height H is about 400 meters and provides a hydrostatic pressure at FO membrane device 10 of up to 40 bars with some loss due to friction through pipeline 152. In addition to the substantial hydrostatic pressure afforded by the difference in height, the osmosis pressure gradient due to the difference in salinity is significant as well. The salinity of the Dead Sea is approximately 350 g/1 as compared to the salinity of the Mediterranean Sea and the Red Sea that is about 40 g/1. The present inventors have found that the osmosis pressure together with hydrostatic pressure may be used to generate a significant flow of treated water into the Dead Sea. The flow rate of the treated water may depend on properties of FO membrane device and quality of the treated water provided by the FO membrane device.

FIG. 2 is a simplified diagram of the example system of FIG. 1 including additional bypass pipelines in accordance with some example embodiments. According to some example embodiments, a system 150 is configured to be controllably switched from a system configured to replenish waterbody 102 with treated water to a system configured to harness the gravitational flow of water along height H to generate energy. According to some example embodiments, a first bypass pipeline 405 controlled by a valve 409 bypasses FO membrane device 10 and directs flow in pipeline 152 to turbine generator 110. By bypassing FO membrane device 10, energy that would otherwise be expended to overcome resistance to flow across FO membrane device may instead be directed to generate more electricity with turbine generator 110. In some example embodiments, a second bypass pipeline 406 controlled by valve 409 also bypasses FO membrane device 10 and directs flow in pipeline 154 to turbine generator 110. Optionally, flow through pipelines 405 and/or 406 cuts off flow to FO membrane device 10 and therefore pipeline 152 and pipeline 154 seize to be communicating vessels. Instead pipeline 154 may also provide flow in a gravitational direction and the flow may be directed by a bypass pipeline 406 to turbine generator 110. In some example embodiments, electricity generated may supply electricity to a grid. Optionally, the bypass flow line may be operated in a national emergency when power is otherwise not be available. According to some example embodiments, controller 800 selectively control valve 409 and toggling between flow through FO membrane device 10 and bypass pipeline 405 and 406. By directing flow through bypass pipeline 405 and 406, a significant amount of electricity may be immediately generated at the expense of adding seawater from sea 101 in waterbody 102 which may potentially pollute waterbody 102 and/or alter a chemical composition of waterbody 102. Controller 800 may additionally control other components of system 150 including any dedicated pumps, valves, sensors that are associated with and/or included in FO membrane device 10 and/or turbine generator 110.

FIG. 3 is a simplified diagram of an example system to replenish a waterbody, the system harnessing energy both at sea level and at a level of the waterbody in accordance with some example embodiments. According to some example embodiments, a system 200 includes first FO membrane device 10 positioned at or near waterbody 102 and a second FO membrane device 20 positioned at or near sea 101 and in fluid communication with sea 101. According to some example embodiments, seawater from sea 101 is channeled with free flow through pipeline 152 to FO membrane device 10 and flow of brine through pipeline 154 in a direction against gravity may be assisted based on the principle of communicating vessels as described for example in reference to FIG. 1.

According to some example embodiments, second FO membrane device 20 at or near a level of sea 101 is configured to receive flow into a draw side of FO membrane device 20 from pipeline 154 and generate pressurized flow based on the difference in salinity between the brine in pipeline 154 and seawater in sea 101 that is circulated in and out of feed side of FO membrane device 20 through pipeline 252 and 254 respectively. Optionally, flow into and out of one or more of the draw side and feed side of FO membrane device 20 may be actuated with a pump(s) associated with FO membrane device 20 and not shown herein for simplicity purposes. The pressurized flow may then be harnessed to generate energy prior to recycling the brine back to sea 101. In some example embodiments, brine flowing in pipeline 154 provides the draw solution and water from sea 101 provides the feed solution for second FO membrane device 20. Due to the higher salinity of the brine, an osmotic pressure gradient is established and water from sea 101 penetrates through FO membrane device 20 to dilute the brine. According to some example embodiments, the generated flow may be harnessed with a turbine generator 210. In some example embodiments, a hydraulic accumulator 220 stores energy from the generated flow and may also provide for smoothing out pulsating flow. Prior to startup of the system, hydraulic accumulator 220 may be pressurized a selected pressure, e.g. with gas so that flow from FO membrane device 20 is directed to turbine generator 210 whenever the pressure of the flow exceeds the selected pressure in hydraulic accumulator 220. Optionally, hydraulic accumulator 220 is associated with a valve that opens and allows flow into turbine generator 210 based on the pressure rising above the selected pressure. Optionally, energy generated by turbine generator 210 may be used to power one or more devices situated at sea level, e.g. near turbine generator 210. Optionally, energy generated may be used to power a desalination station for generating manufactured water, e.g. for drinking or agriculture.

According to some example embodiments, system 200 may be operated with little energy expenditure from an external power source, e.g. the flow may be partially and/or substantially self- powered. One or more valves 160 may provide for shutting down operation of system 200 and/or controlling the rate at which treated water flow is expelled through pipeline 157 into waterbody 102. Optionally, controller 800 controls operation of FO membrane device 10 including control of valves 160 and pump 120 as well as any valves, sensors and pumps included and/or associated with operation of FO membrane device 20 and RO membrane device 320. Optionally, controller 800 controls operation of hydraulic accumulator 220.

FIG. 4 is a simplified diagram of an example system to replenish a waterbody, the system including a desalination station in accordance with some example embodiments. According to some example embodiments, in a system 250 is similar to system 200 and additionally includes a desalination station 315.

According to some example embodiments, desalination station 315 includes a pump 310, an RO membrane device 320, and optionally a pressure exchanger 330. Pump 351 pumps water from sea 101 into a first side of RO membrane device 320 based on which manufactured water 350 is drawn across RO membrane device 320 to a second opposite side of RO membrane device 320. Outflow from second side of RO membrane device 320 provides manufactured water 350 that may be used as drinking water, water of agriculture and/or for industry. Brine from the first side of RO membrane device 320 maybe directed by free flow through pipeline 353 back into sea 101.

In some example embodiments, pump 310 actively pumps seawater from sea 101 to RO membrane device 320. In addition, pressure exchanger 330 couples downstream flow of brine through pipeline 353 with upstream flow through a pipeline 352 to boost flow of seawater from sea 101 to RO membrane device 320. Pressure exchanger 330 may harness energy of water flow through pipeline 353 flowing in a gravitational direction to actuate pressurized flow of seawater from sea 101 through a pipeline 352 and into RO membrane device 320. Optionally, up to approximately 60%, e.g. 20 %- 70% of the feed solution is provided by pressure exchanger 330 and the rest is actuated with pump 310. In some example embodiments, pressure exchanger 330 is a PX® Pressure Exchanger® manufactured by Energy Recovery in San Leandro, CA.

According to some example embodiments, pump 310 is partially powered with energy harnessed in system 250. Optionally, pump 310 may be at least partially powered by energy generated with turbine generator 210. Optionally, an external power source is applied to operated pump 310 at startup of system 250 and subsequently once flow through system 250 is established, system 250 may switch to power assisted mode with pump 310 controllably actuated as needed based on power from turbine generator 210.

According to some example embodiments, system 250 provides a partially and/or substantially self-powered system that both replenishes waterbody 102 with treated water and produces manufactured water at the level of sea 101 for drinking, agriculture and/or manufacturing. One or more valves 160 may provide for shutting down operation of system 250 and/or controlling the rate at which treated water flow is expelled through pipeline 157 into waterbody 102. Optionally, controller 800 controls operation of valves 160 and pump 120. Optionally, controller 800 controls operation of additional components of system 250 including desalination station 315 and hydraulic accumulator 220. FO membrane device 10, FO membrane device 20, RO membrane device 320, hydraulic accumulator 220, turbine generator 110 and/or turbine generator 210 may be controlled with controller 800.

FIG. 5 is a simplified diagram of a system including a desalination station and bypass pipelines in accordance with some example embodiments. According to some example embodiments, system 300 is similar to system 250 and additionally includes one or more bypass pipelines 405 and 406 that direct seawater from sea 101 in one or more of pipe line 152 and pipeline 154 to turbine generator 110 at a level of waterbody 102. As discussed in reference to FIG. 2, first bypass pipeline 405 controlled by valve 409 may bypass FO membrane device 10 and direct flow in pipeline 152 to turbine generator 110. By bypassing FO membrane device 10, energy that would otherwise be expended to overcome resistance to flow across FO membrane device may instead be directed to generate more electricity with turbine generator 110. Optionally, second bypass pipeline 406 controlled by valve 409 may also bypass FO membrane device 10 and direct flow in pipeline 154 to turbine generator 110. Optionally, flow through pipelines 405 and/or 406 cuts off flow to FO membrane device 10 and therefore pipeline 152 and pipeline 154 seize to be communicating vessels. Instead pipeline 154 may also provide flow in a gravitational direction and the flow may be directed by a bypass pipeline 406 to turbine generator 110. Optionally, controller 800 controls operation of valves 409 as well as other components of system 300. According to some example embodiments, system 300 is configured to be controllably switched from a system configured to replenish waterbody 102 with treated water and to generate manufactured water 350 to a system configured to harness the gravitational flow of water along height H to generate energy as discussed in reference to FIG. 2.

FIG. 6 is a simplified diagram another example system to replenish a waterbody, the system including a desalination station in accordance with some example embodiments. According to some example embodiments, in a system 350 energy in flow through pipeline 152 due to free flow of seawater from sea 101 to a level at or near waterbody 102 is first harnessed with a turbine generator 510 and then outflow from turbine generator 510 is directed to a feed side of FO membrane device 10. According to some example embodiments, flow through pipeline 152 is seawater from sea 101.

Draw solution 151 from waterbody 102 fills the draw side of FO membrane device and the osmosis pressure gradient leads to a flow of treated water across FO membrane device 10 and out through pipeline 156 that is directed to a pressure exchanger 530. In some example embodiments, pressurized flow in pipeline 156 drives flow through pipeline 154 in a direction against gravity. Optionally, pipeline 154 includes a flow of brine from FO membrane device 10 to FO membrane device 20. Due to a difference in salinity between brine in pipeline 154 and seawater in sea 101, treated water from sea 101 is extracted to dilute the brine and a flow through FO membrane device 20 is generated. The generated flow may be harnessed with turbine generator 210 to generate electricity. In some example embodiments, a hydraulic accumulator 220 stores energy from the generated flow and may also provide for smoothing out pulsating flow. As described in reference to FIG. 4, pump 310 of desalination station 315 may be powered with energy generated with turbine generator 210.

According to some example embodiments, system 350 may additionally include one or more bypass pipelines, each controlled with a dedicated valve that is configured to controllably switch operation of system 350 from a system configured to replenish waterbody 102 with treated water to a system configured to harness the gravitational flow of water along height H to generate energy. The bypass pipelines and flow for generating electricity may be as described for example in reference to FIG. 2 and FIG. 5.

According to some example embodiments, system 350 provides a partially and/or substantially self-powered system that both replenishes waterbody 102 with treated water and produces manufactured water 350 at the level of sea 101 for drinking, agriculture and/or manufacturing. Valve 160 may provide for shutting down operation of system 350 and/or controlling the rate at which treated water flow is expelled through pipeline 156 into waterbody 102. Optionally, controller 800 controls operation of valves 160, desalination station 315 and hydraulic accumulator 220 as well as other components included in system 350.

FIG. 7 is a simplified diagram of an example system to replenish a waterbody, the system including a pump to actuate flow from the waterbody to sea level, in accordance with some example embodiments. According to some example embodiments, system 400 may be based on system 200 and additionally include an additional turbine generator 510 along pipeline 152 and a pump 520 along pipeline 154. In example system 400, turbine generator 510 and pump 520 may be used in place of the principle of communicating vessels to drive the cyclic flow of seawater from sea 101 to waterbody 102 and back to sea 101. According to some example embodiments, seawater from sea 101 may freely flow through pipeline 152 down to turbine generator 510 at a level substantially near a level of waterbody 102 at a height H below sea 101. Energy in flow through pipeline 152 due to the drop in height may be harnessed in a turbine generator 510 prior to directing the flow to FO membrane device 10. Optionally, output from turbine generator 510 may be directed to a feed side of FO membrane device 10 with pipeline 153, e.g. free flow through pipeline 153. On a draw side of FO membrane device 10, water from waterbody 102 is introduced. Due to a difference in salinity between sea 101 and waterbody 102, an osmotic pressure gradient across FO membrane device 10 is established and treated penetrates through FO membrane device 10, dilutes draw solution and generates a flow of through pipeline 156. According to some example embodiments, brine formed on a feed side of FO membrane device 10 is recycled back to sea 101 by pumping the brine up to FO membrane device 20 at the level of sea 101 with a pump 520. Optionally, pump 520 may be powered with electricity generated by one or more of turbine generator 110 and turbine generator 510.

According to some example embodiments, system 400 may additionally include one more bypass pipelines, each controlled with a dedicated valve that is configured to controllably switch operation of system 400 from a system configured to replenish waterbody 102 with treated water to a system configured to harness the gravitational flow of water along height H to generate energy. The bypass pipelines and flow for generating electricity may be as described for example in reference to FIG. 2 and FIG. 5.

According to some example embodiments, system 400 provides a partially and/or substantially self-powered system that replenishes waterbody 102 with treated water. Valve 160 may provide for shutting down operation of system 400 and/or controlling the rate at which treated water flow is expelled through pipeline 157 into waterbody 102. Optionally, controller 800 controls operation of valve 160 and hydraulic accumulator 220. Controller 800 may control for example operation of additional components in system 400 including for example, pump 520, turbine generator 510, turbine generator 110, turbine generator 210, FO membrane device 10 and FO membrane device 20.

FIG. 8 is a simplified diagram of an example system to replenish a waterbody, the system in fluid communication with two different sea bodies, in accordance with some example embodiments. A system 450 may be similar to system 400. According to some example embodiments, the difference between system 450 and system 400 is that in system 450, pipeline 152 directs free flow of seawater from a first sea 101 toward an FO membrane device 10 near a waterbody 102 below sea level and recycles the brine generated in FO membrane device 10 to a second sea 103 via a pipeline 154. Optionally, a pump 520 actuates flow of brine toward second sea 103. Optionally, pump 520 may be powered with energy generated in one or more of turbine generators 510 and 110 both positioned near waterbody 102. In some example embodiments, first sea 101 is the Mediterranean Sea and second sea 103 is the Red Sea. In an alternate example embodiments, first sea 101 is the Red Sea and second sea 103 is the Mediterranean Sea.

FIG. 9 is a simplified diagram of an example system to replenish a waterbody with seawater desalinated at sea level in accordance with some example embodiments. According to some example embodiments, a system 500 includes a desalination station 315 at sea level configured to desalinate the seawater that is to be used for replenishing waterbody 102. According to some example embodiments, the desalinated water once generated, freely flows in pipeline 152 down toward level of waterbody 102. Outflow from pipeline 152 may for example be directed to turbine generator 510 to harness energy of flow due to the drop in height H below level of sea 101. Outflow from turbine generator 510 provides a feed solution to FO membrane device 10. On an opposite side of FO membrane device 10 water from waterbody 102 through pipeline 151 provides the draw solution that is diluted with the desalinated water supplied in pipeline 152 and expelled from turbine generator 510.

According to some example embodiments, desalination station 615 includes a pump 310 that pumps seawater from sea 101 into RO membrane device 320. Desalinated water may be extracted through RO membrane device 320 and may flow through pipeline 650. Optionally, a first portion of flow through pipeline 650 is accumulated as manufactured water 350 and a second portion is directed through pipeline 152 to replenish waterbody 102.

According to some example embodiments, system 500 may additionally include one more bypass pipelines, each controlled with a dedicated valve 409 that is configured to controllably switch operation of system 500 from a system configured to replenish waterbody 102 with treated water as well as generate manufactured water to a system configured to harness the gravitational flow of water along height H to generate energy. Energy may be harness with turbine generator 510. The bypass pipelines and flow for generating electricity may be as described for example in reference to FIG. 2 and FIG. 5.

According to some example embodiments, system 500 provides a partially and/or substantially self-powered system that replenishes waterbody 102 with treated water and produces manufactured water 350. Optionally, controller 800 controls operation of pump 310 that drives operation of system 500 as well as other components in system 500. Optionally, pump 310 may be powered or powered assisted with energy generated in turbine generators 621.

Reference is now made to FIG. 10 showing a diagram of an example system for replenishing a body of water where the transfer of water between the waterbody and sea is performed at sea level in accordance with some example embodiments. According to some example embodiments, a system 550 for replenishing waterbody 102 pumps water from waterbody 102 to sea level of sea 101 and uses pumped water to establish an osmotic pressure gradient to actuate a treating process through at least one FO membrane device 11. According to some example embodiments, a pump 120 pumps water through a pipeline 552 up to a level of sea 101 and into a draw side of FO membrane device 11. On a feed side of FO membrane device 11 seawater from sea 101 is provided, e.g. via pipeline 551. Due to the difference in salinity between waterbody 102 and sea 101, an osmotic pressure gradient is established across FO membrane device 11 and treated water is extracted from feed side to dilute the water channeled from waterbody 102. The high pressure flow of diluted water exiting FO membrane device 11 and flowing through pipeline 556 may be harnessed with turbine generator 210 and hydraulic accumulator 220 to generate power. Outflow from turbine generator 210 may freely flow down to waterbody 102 through a pipeline 553. Optionally, energy accumulated due to the drop in height H of the water flowing through pipeline 553 is harnessed with turbine generator 510. In some example embodiments, power generated with turbine generator 510 powers and/or power assists pump 120.

In some example embodiments, further harnessing of energy may be provided based on directing brine formed from FO membrane device 11 through a pipeline 554 to FO membrane device 20 that is configured to dilute the generated brine prior to cycling the brine back to sea 101 and to harness the energy of the flow of the diluted brine with turbine generator 710. Optionally, power generated in turbine generator 210 and 710 is used to power and/or power assist devices operated at sea level.

According to some example embodiments, system 550 may additionally include one more bypass pipelines, each controlled with a dedicated valve that is configured to controllably switch operation of system 550 from a system configured to replenish waterbody 102 with treated water to a system configured to harness the gravitational flow of water along height H to generate energy. The bypass pipelines and flow for generating electricity may be as described for example in reference to FIG. 2 and FIG. 5.

According to some example embodiments, system 550 provides a partially and/or substantially self-powered system that replenishes waterbody 102 with treated water. Optionally, controller 800 controls operation of one or more components of system 550 including pump 120 that drives operation of system 550. Optionally, pump 310 may be powered or powered assisted with energy generated in turbine generator 510.

It is appreciated that certain features of the invention, which are, for clarity described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.

Claims

WHAT IS CLAIMED IS:

1. A system (100) for replenishing a salt waterbody (102) that has a salinity greater than seawater (101) while substantially retaining its chemical composition, wherein the salt waterbody (102) is at a level below sea level, the system comprising: a first forward osmosis (FO) membrane device (10) in proximity to the salt waterbody (102), the FO membrane device (102) configured for generating a flow of treated seawater into the salt waterbody for replenishing the salt waterbody, said FO membrane device including a feed side (10a) and a draw side (10b); a first pipeline (152) extending between at least one sea (101) and the salt waterbody (102) and configured for channeling the seawater from said at least one sea (101) to said feed side (10a) with gravitational flow, wherein said channeling is configured to impose a hydrostatic pressure on said feed side (10a); a second pipeline (154) extending between said at least one sea (101) and the salt waterbody (102) and configured for channeling brine on said feed side (10a) back to said at least one sea (101) in a direction against gravity, a first pump configured to assist overcoming friction of flow in said second pipeline (154); wherein said second pipeline (154) is fluidly connected to said first pipeline (152) at said feed side (10a), said first pipeline (152) and said second pipeline (154) defining communicating vessels and wherein flow through said second pipeline (154) toward said at least one sea is configured to be actuated based on principle of communicating vessels and said second pump; a second circulation pump (120) configured to circulate water from the salt waterbody (102) to said draw side (10b) of said first FO membrane device (10); and an outlet (156) from said draw side configured for expelling said generated flow of treated seawater into the salt waterbody (102), wherein said generated flow is actuated based on an osmotic pressure gradient across said first FO membrane device based on said hydrostatic pressure and based on drop of elevation of the seawater in said first pipeline (152).

2. The system of claim 1, wherein the salt waterbody is the Dead Sea and wherein said at least one sea is selected from a group consisting of the Mediterranean Sea and the Red Sea.

3. The system of claim 1 or claim 2, comprising a first power generator (110) configured to harness energy from said generated flow and to power at least one of said first FO membrane device (10) and said second circulation pump (120) with said first power generator (110).

4. The system of claim 3, wherein said first power generator (110) is a turbine generator.

5. The system of claim 3 or claim 4 comprising: at least one bypass pipeline (405) configured to bypass flow of the seawater to said first FO membrane device (10) and instead direct flow through said first pipeline (152) to said first power generator (110); and a bypass valve (409) configured to selectively control bypassing of said flow through said at least one bypass pipeline (405).

6. The system of claim 5, wherein said at least one bypass pipeline includes a first bypass pipeline (405) configured to establish bypass flow from said first pipeline (152) to the first power generator (110) and a second bypass pipeline (154) configured to establish bypass flow from said second pipeline (154) to said first power generator (110).

7. The system of any one of claims 1-6, comprising: a second FO membrane device (20) at said sea level configured to generate flow therethrough based on an osmotic pressure gradient between said brine expelled from said second pipeline and said seawater; and a second power generator (210) configured to harness energy of said generated flow.

8. The system of claim 7, comprising a hydraulic accumulator (220) in fluid communication with said second power generator, wherein the hydraulic accumulator (220) is configured to be pressurized to a selected pressure and direct flow to said second power generator (210) from said second FO membrane device (20) based on pressure of said flow exceeding the selected pressure.

9. The system of claim 7 or claim 8, comprising a desalination station (315) configured to produce manufactured water from said seawater, wherein said desalination station (315) is configured for being powered by said second power generator (210).

10. The system of any one of claims 1-9, comprising a third power generator (510) positioned upstream from said first FO membrane device (10) and configured to harness energy of flow through said first pipeline (152).

11. The system of claim 10, comprising: a third pipeline (156) connected to said outlet (156); and a pressure exchanger (530) configured for boosting flow through said second pipeline (154) based on flow through said third pipeline (156).

12. The system of any one of claims 1-11, wherein said first pipeline (152) extends to a first sea (101) and said second pipeline (154) extends to a second sea (103) that is other than the first sea.

13. A method for replenishing a salt waterbody that has a salinity greater than seawater while substantially retaining its chemical composition, wherein the salt waterbody is at a level below sea level, the method comprising: providing a first forward osmosis (FO) membrane device in proximity to the salt waterbody, wherein the FO membrane device is configured for generating a flow of treated seawater into the salt waterbody for replenishing the salt waterbody, said FO membrane device including a feed side and a draw side; channeling the seawater with gravitational flow from at least one sea to said feed side through a first pipeline, wherein said channeling is configured to impose a hydrostatic pressure on said feed side due to a drop in height of said seawater through said first pipeline; channeling brine on said feed side to said at least one sea through a second pipeline in a direction against gravity, wherein said first pipeline and said second pipeline are communicating vessels wherein flow through said second pipeline toward said at least one sea is actuated based on the principle of communicating vessels and a first pump at an outlet of said second pipeline; circulating water from the salt waterbody to said draw side of said first FO membrane device with a first circulation pump; and expelling said generated flow of treated seawater into the salt waterbody, wherein said generated flow is actuated based on an osmotic pressure gradient across said first FO membrane device and based on said hydrostatic pressure created by drop of elevation.

14. The method of claim 13, wherein the salt waterbody is the Dead Sea and wherein said at least one sea is selected from a group consisting of the Mediterranean Sea and the Red Sea.

15. The method of claim 13 or claim 14, comprising harnessing energy from said generated flow to power at least one of said first FO membrane device and said first circulation pump.

16. The method of any one of claims 13-15, comprising selectively bypassing flow of the seawater to said first FO membrane device and instead directing the flow through said first pipeline to a first power generator.

17. The method of any one of claims 13-16, comprising recycling said brine into said at least one sea with a second FO membrane device, and harnessing energy of flow generated through said second FO membrane.

18. The method of claim 17, comprising producing manufactured water from the seawater and powering assisting the desalination from said energy harnessed with said second FO membrane device.

19. The method of anyone of claims 13-18 comprising boosting flow from the salt waterbody to the sea with a pressure exchanger.

20. The method of any one of claims 13-19, wherein the seawater in the first pipeline is channeled from a first sea and said brine in said second pipeline is channeled to a second sea that is other than the first sea.