WO2011050473A1 - Procédé et système combinés de dessalement de l'eau salée et de production d'électricité - Google Patents

Procédé et système combinés de dessalement de l'eau salée et de production d'électricité Download PDF

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Publication number
WO2011050473A1
WO2011050473A1 PCT/CA2010/001718 CA2010001718W WO2011050473A1 WO 2011050473 A1 WO2011050473 A1 WO 2011050473A1 CA 2010001718 W CA2010001718 W CA 2010001718W WO 2011050473 A1 WO2011050473 A1 WO 2011050473A1
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WIPO (PCT)
Prior art keywords
red
stack
edr
diluent
concentrate
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Application number
PCT/CA2010/001718
Other languages
English (en)
Inventor
Benjamin Stuart Sparrow
Joshua Aniket Zoshi
James Hing Bong Tang
Henry Kwan Keung Tsin
Nicholas Christian Roch
Original Assignee
Saltworks Technologies Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from PCT/CA2010/000537 external-priority patent/WO2010115287A1/fr
Application filed by Saltworks Technologies Inc. filed Critical Saltworks Technologies Inc.
Publication of WO2011050473A1 publication Critical patent/WO2011050473A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
    • C02F1/4693—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis electrodialysis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/22—Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen
    • H01M8/227—Dialytic cells or batteries; Reverse electrodialysis cells or batteries
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • C02F1/46109—Electrodes
    • C02F2001/46119—Cleaning the electrodes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/08—Seawater, e.g. for desalination
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4612—Controlling or monitoring
    • C02F2201/46125—Electrical variables
    • C02F2201/4613—Inversing polarity
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4618—Supplying or removing reactants or electrolyte
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/10—Energy recovery
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/16—Regeneration of sorbents, filters
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y02A20/131—Reverse-osmosis
    • 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
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • 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
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/30—Wastewater or sewage treatment systems using renewable energies

Definitions

  • the present disclosure is directed at a method and system for desalinating saltwater while generating electricity.
  • Saltwater in the form of seawater constitutes about 97% of the water on Earth. Unless seawater is sufficiently desalinated, though, it is not only undrinkable but unsuitable for agriculture. "Desalination” refers to the process of removing anions and cations from saltwater. Seawater typically has a salt concentration of about 3.5% salt by mass; that is, about 35 grams of dissolved salt per liter of water. Another source of saltwater is salty, underground aquifer water, also known as "brackish water". The salt concentration of brackish water typically ranges from less than 1% to more than 18% salt by mass. In contrast, drinkable water typically has a salt concentration of, at most, about 0.04%.
  • a method for desalinating saltwater while generating electricity includes generating electricity using a reverse electrodialysis (RED) stack, and utilizing the electricity to desalinate saltwater in an electrodialysis reversal (EDR) stack.
  • the RED stack may have an output impedance that is matched to an input impedance of the EDR stack.
  • the RED stack may be one of a plurality of separate RED stacks electrically coupled to each other to generate the electricity
  • the EDR stack may be one of a plurality of separate EDR stacks electrically coupled to each other to desalinate the saltwater.
  • the method may also include determining a cost of electricity, and when the cost of electricity is below a low cost threshold, doing one or both of powering at least some of the separate EDR stacks using purchased electricity and converting at least some of the separate RED stacks into the EDR stacks to desalinate the saltwater.
  • the method may include doing one or both of selling electricity generated using at least some of the RED stacks and converting at least some of the separate EDR stacks into the RED stacks to generate the electricity.
  • the method may also include periodically backflushing one or both of the RED and EDR stacks by reversing the direction of fluid flow through at least one of the stacks.
  • the method may also include determining one or more of water volume delivery need and power system need, and based on values for at least one of volume delivery need and power system need, accordingly adjusting at least one of rate at which the electricity is generated and at which the saltwater is desalinated.
  • the RED stack may be one of a plurality of RED stacks and the EDR stack may be one of a plurality of EDR stacks, and the method may also include utilizing a switching network configured to electrically couple any one or more of the RED stacks to any one or more of the EDR stacks. Any one or more of the RED stacks may have an output impedance that is matched to an input impedance of the any one or more EDR stacks.
  • a portion of the electricity generated using the RED stack may be transmitted to a power grid.
  • the RED stack may have an RED concentrate and an RED diluent flowing through it, and the method can also include evaporating water from at least some of the RED concentrate and the RED diluent exiting the RED stack, and harvesting salt that precipitates following evaporation. Substantially all the water may be evaporated from the at least some of the RED concentrate and the RED diluent. Additionally or alternatively, one or both of the RED concentrate and the RED diluent that is recycled may be heated utilizing waste heat from a process plant to facilitate evaporation to air.
  • the EDR stack may also have an EDR diluent and product that is desalinated flowing therethrough, and the method may also include recycling the EDR diluent exiting the EDR stack into the RED diluent entering the RED stack. Additionally or alternatively, the method may also include mixing the EDR diluent exiting the EDR stack with a solution having a concentration less than an EDR diluent threshold to lower the concentration of the EDR diluent, and following mixing, recycling the EDR diluent exiting the EDR stack by using it as the EDR diluent entering the EDR stack.
  • the method may also including mixing the RD diluent exiting the RED stack with a solution having a concentration less than an RED diluent threshold to lower the concentration of the RED diluent, and following mixing, recycling the RED diluent exiting the RED stack by using it as the RED diluent entering the RED stack.
  • the method may also include de-scaling the RED stack by reversing the polarity of the RED stack.
  • a system for desalinating saltwater while generating electricity includes an RED stack configured to generate electricity, and an EDR stack electrically coupled to the RED stack such that the electricity generated by the RED stack is used to desalinate saltwater in the EDR stack.
  • the RED stack may have an output impedance that is matched to an input impedance of the EDR stack.
  • the RED stack may be one of a plurality of separate RED stack electrically coupled to each other to generate the electricity and the EDR stack may be one of a plurality of separate EDR stacks electrically coupled to each other to desalinate the saltwater.
  • the system may also include a switching network electrically coupled between the plurality of RED stacks and the plurality of EDR stacks such that any one or more of the RED stacks can be electrically coupled to any one or more of the EDR stacks.
  • Any one or more of the RED stacks may have an output impedance that is matched to an input impedance of the any one or more EDR stacks.
  • the RED stack may have an RED concentrate and RED diluent flowing through it.
  • the system may also include a salt harvesting device and a reconcentrator fluidly coupled to an outlet of the RED stack through which the RED concentrate and the RED diluent exit the RED stack and to the salt harvesting device.
  • the reconcentrator may be configured to evaporate water from at least some of the RED concentrate and the RED diluent exiting the RED stack to facilitate harvesting of salt from the RED concentrate and RED diluent using the salt harvesting device. Substantially all the water may be evaporated from the at least some of the RED concentrate and the RED diluent.
  • the reconcentrator may be fluidly coupled between an outlet of the RED stack through which one or both of the RED concentrate and RED diluent exit the RED stack and an inlet of the RED stack through which the RED concentrate enters the RED stack such that one or both of the RED concentrate and RED diluent exiting the RED stack can be recycled for use as the RED concentrate that enters the RED stack.
  • the system may also include a process plant comprising a source of waste heat, and a heat exchanger fluidly coupled between the outlet of the RED stack and the reconcentrator configured to heat one or both of the RED concentrate and RED diluent to facilitate evaporation to air.
  • a process plant comprising a source of waste heat, and a heat exchanger fluidly coupled between the outlet of the RED stack and the reconcentrator configured to heat one or both of the RED concentrate and RED diluent to facilitate evaporation to air.
  • the RED stack may have an RED concentrate and an RED diluent flowing through it
  • the EDR stack may have an EDR diluent and product that is desalinated flowing through it.
  • the system may also include piping fluidly coupling an outlet of the EDR stack through which the EDR diluent exits the EDR stack to an inlet of the RED stack through which the RED diluent enters the RED stack such that the EDR diluent exiting the EDR stack can be recycled as the RED diluent entering the RED stack.
  • the system may also include piping fluidly coupling an outlet of the EDR stack through which the EDR diluent exits the EDR stack to an inlet of the EDR stack through the EDR diluent enters the EDR stack such that the EDR diluent exiting the EDR stack can be recycled as the EDR diluent entering the EDR stack; and an EDR diluent mixer disposed along the piping and fluidly coupled to a source of solution having a concentration less than an EDR diluent threshold.
  • the EDR diluent mixer is configured to mix the solution and the EDR diluent being recycled to lower the concentration of the EDR diluent prior to the EDR diluent entering the EDR stack.
  • the system may include piping fluidly coupling an outlet of the RED stack through which the RED diluent exits the RED stack to an inlet of the RED stack through which the RED diluent enters the RED stack such that the RED diluent exiting the RED stack can be recycled as the RED diluent entering the RED stack; and an RED diluent mixer fluidly coupled along the piping and to a source of solution having a concentration less than an RED diluent threshold.
  • the RED diluent mixer can be configured to mix the solution and the RED diluent being recycled to lower the concentration of the RED diluent prior to the RED diluent entering the RED stack.
  • the RED stack can be de-scaled by reversing the polarity of the RED stack.
  • a system for desalinating saltwater while generating electricity includes a first desalination plant for desalinating saltwater and having a brine discharge outlet; and a second desalination plant.
  • the second desalination plant includes a RED stack configured to generate electricity, the RED stack having an RED concentrate and an RED diluent flowing therethrough; and an EDR stack having an EDR diluent and product flowing therethrough, the EDR stack electrically coupled to the RED stack such that the electricity generated by the RED stack is used to desalinate the product in the EDR stack.
  • the brine discharge outlet is fluidly coupled to the EDR stack such that brine discharged from the first desalination plant is desalinated.
  • the brine discharge outlet may be fluidly coupled to the RED stack such that the brine discharged from the first desalination plant is used as the RED concentrate to generate the electricity.
  • the second desalination plant may include a reconcentrator fluidly coupled between the brine discharge outlet and the RED stack.
  • An outlet of the EDR stack may be fluidly coupled to the first desalination plant such that desalinated brine is output to the first desalination plant for further desalination.
  • the RED stack may be de-scaled by reversing the polarity of the RED stack.
  • a method for desalinating saltwater while generating electricity includes obtaining brine discharged from a first desalination plant, and utilizing the brine as product to be desalinated in a second desalination plant configured to desalinate saltwater according to a method including generating electricity using a RED stack, the RED stack having an RED concentrate and an RED diluent flowing therethrough; and utilizing the electricity to desalinate saltwater in an EDR stack having an EDR diluent and the product flowing therethrough, the EDR stack electrically coupled to the RED stack such that the electricity generated by the RED stack is used to desalinate the product in the EDR stack.
  • the brine discharged from the first desalination plant may be used as the RED concentrate.
  • a portion of the brine may be evaporated to air to increase its concentration prior to using it as the RED concentrate.
  • Desalinated brine may be returned from the second desalination plant to the first desalination plant for further desalination.
  • the RED stack may be de-scaled by reversing the polarity of the RED stack.
  • a computer readable medium having encoded thereon statements and instructions to cause a controller to execute any of the foregoing methods.
  • the foregoing allows for electricity to be generated with the RED stacks while product is desalinated using the EDR stacks.
  • a relatively high recovery ratio can be achieved and problems associated with scaling of conventional desalination plants can be mitigated by performing de-scaling on the concentration difference energy plant and by having the concentration difference energy plant remove the relatively large ionic species that are primarily responsible for scaling.
  • Figure 1 is a schematic view of a system for desalinating saltwater while generating electricity according to one embodiment in which a reverse electrodialysis (RED) stack is used to generate electricity to power an electrodialysis reversal (EDR) stack that desalinates the saltwater.
  • RED reverse electrodialysis
  • EDR electrodialysis reversal
  • Figure 2 is a schematic view of a system for desalinating saltwater while generating electricity according to another embodiment in which the RED and EDR stacks form part of a plant.
  • Figure 3 is a schematic view of a system for desalinating saltwater while generating electricity according to another embodiment in which multiple RED and EDR stacks are electrically coupled using a switching network and in which the switching network is electrically coupled to a power grid.
  • Figure 4 is a schematic view of a system for desalinating saltwater while generating electricity according to another embodiment in which the RED and EDR stacks form part of a combined desalination plant that includes a first desalination plant that discharges brine, and in which the brine discharged from the first desalination plant is used to replenish RED concentrate used in the RED stack.
  • Figure 5 is a schematic view of a system for desalinating saltwater while generating electricity according to another embodiment in which the RED and EDR stacks form part of a plant having a salt harvesting device and a reconcentrator that are used in conjunction to substantially reduce the amount of liquid discharged from the plant.
  • Figure 6 is a schematic view of a system for desalinating saltwater while generating electricity according to another embodiment in which the RED and EDR stacks form part of a combined desalination plant that includes a first desalination plant that discharges brine, and in which the brine discharged from the first desalination plant is subsequently desalinated using the EDR stack, and is then subsequently returned to the first desalination plant for further desalination.
  • concentration difference energy Two ionic solutions that differ only in the concentration of the solute dissolved therein have different amounts of chemical energy. This difference in chemical energy is hereinafter referred to as "concentration difference energy".
  • concentration difference energy When equal volumes of solutions of saltwater and freshwater are placed in adjacent chambers and are separated from each other solely by a membrane that is water, but not ion, permeable, the concentration difference energy results in the two solutions seeking concentration equilibrium whereby water from the freshwater chamber flows into the saltwater chamber.
  • Ion exchange membranes include "cation exchange membranes" and “anion exchange membranes”. Cation and anion exchange membranes are those membranes that allow only cations (positively charged ions) and anions (negatively charged ions) to pass therethrough, respectively.
  • Exemplary cation exchange membranes include Neosepta CMX, CM-1; Ralex CMH-PES; Fumasep FKE, FKD; and Selemion CMV membranes.
  • Exemplary anion exchange membranes include Neosepta AM-1, AFN, AMX; Ralex AMH-PES; Fumasep FAD; and Selemion DVS, APS membranes.
  • Concentration difference energy can be used to generate electricity in a reverse electrodialysis (RED) stack.
  • RED stack a series of chambers are separated by an alternating series of anion and cation exchange membranes.
  • the chambers are typically tilled with one of two different ionic solutions: an RED concentrate and an RED diluent.
  • the RED concentrate has a higher ionic concentration than the RED diluent.
  • one of the chambers in the pair contains the RED concentrate and the other of the chambers in the pair contains the RED diluent.
  • the concentration difference energy that results is used to generate a voltage and current at electrodes that sandwich the chambers.
  • Electrodialysis reversal (EDR) stacks use a similar arrangement of chambers to desalinate saltwater.
  • an EDR stack includes a series of chambers separated by an alternating series of anion and cation exchange membranes.
  • the chambers are typically filled with one of two different ionic solutions: an EDR diluent and product feed, which is the saltwater to be desalinated.
  • an EDR diluent and product feed which is the saltwater to be desalinated.
  • one of the chambers in the pair contains the product feed and the other of the chambers in the pair contains the EDR diluent.
  • a DC voltage can be applied across the EDR stack in order to drive cations and anions out of the chambers containing the product feed into the EDR diluent, thus desalinating the product feed.
  • the present disclosure is directed at a method and system that utilizes concentration difference energy to desalinate saltwater.
  • an RED stack is used to generate electricity using concentration difference energy.
  • the electricity is then used to drive an EDR stack to desalinate the saltwater.
  • this method and system are beneficial for several reasons. For example, because RED and EDR stacks are similarly constructed, when economical to do so the RED stack may be converted into an EDR stack and used to desalinate saltwater, or the EDR stack may be converted into an RED stack and used to generate electricity that can be sold to an electrical utility.
  • an EDR stack 110 that is electrically coupled to an RED stack 150 via a conductor 126.
  • an anode 103 and a cathode 104 each of which is adjacent to a different electrolyte chamber 156.
  • Between the electrolyte chambers 156 is an alternating series of RED concentrate chambers 162 and RED diluent chambers 164. Separating adjacent RED concentrate and diluent chambers 162, 164, and separating the RED concentrate and diluent chambers 162, 164 from the electrolyte chambers 156, is either an anion exchange membrane 151 or a cation exchange membrane 153.
  • the anion and cation exchange membranes 151, 153 are also arranged in an alternating series within the RED stack 150.
  • RED concentrate When in operation, RED concentrate is pumped through the RED concentrate chambers 162 via RED concentrate manifolds 152, RED diluent is pumped through the RED diluent chambers 164 via RED diluent manifolds 154, and an electrolyte is pumped through the electrolyte chambers 156 via electrolyte manifolds 108.
  • the RED concentrate and the RED diluent are both ionic solutions, with the RED concentrate having a higher ionic concentration than the RED diluent; in an exemplary embodiment, both the RED concentrate and the RED diluent are saltwater.
  • This movement of cations and anions throughout the RED stack 150 is referred to as an "ionic current", and in the electrolyte chambers 156 oxidation (at the anode 103) and reduction (at the cathode 104) reactions occur that convert this ionic current into an DC electrical current, which allows the RED stack 150 to be used as a voltage source.
  • the voltage that the RED stack 150 generates is applied to the EDR stack 110.
  • the structure of the EDR stack 110 is similar to that of the RED stack 150, although the manner in which the EDR stack 110 is used differs from that of the RED stack 150, and the nomenclature used to describe the EDR stack 110 consequently differs from that used to describe the RED stack 150.
  • product feed to be desalinated is pumped through EDR product chambers 112 via product feed manifolds 102
  • EDR diluent is pumped through EDR diluent chambers 114 via EDR diluent manifolds 105
  • the electrolyte is pumped through the electrolyte chambers 156 via the electrolyte manifolds 108.
  • at the ends of the EDR stack 110 are the anode 103 and the cathode 104.
  • the electrical current applied to the electrodes of the EDR stack 110 is converted into ionic current in the EDR stack 1 10's electrolyte chambers 156.
  • the electric field applied to the EDR stack 110 drives cations and anions out of the EDR product chambers 112 and through cation exchange membranes 153 and anion exchange membranes 151, respectively, and into adjacent EDR diluent chambers 114.
  • a power supply 128 can be placed in the electric circuit if the voltage that the RED stack 150 generates is less than the threshold voltage required to desalinate the product feed.
  • an electrical load (not depicted) can be placed in the electric circuit and operate using electricity generated by the RED stack 150.
  • the same electrolyte can be used in all four of the electrolyte chambers 156.
  • one type of electrolyte can be used in the RED stack 150, while another type of electrolyte can be used in the EDR stack 110.
  • different anolytes and catholytes can be used in any or all of the stacks 110, 150.
  • four different electrolytes may be used in the embodiment of Figure 1.
  • An exemplary list of electrolytes follows in Table 1 :
  • the electrolyte combination in row vi. of Table 1 is beneficial in that two forms of Fe(CN) 6 are stable and stay in solution, and in that the net electrode voltage for the overall redox reaction is zero. More energy can therefore be used for one or both of desalination and electricity generation.
  • the electrolyte in row i. of Table 1 is beneficial in that hydrogen gas can be produced, albeit by utilizing energy that could otherwise be used for one or both of desalination and electricity generation.
  • the stacks 110, 150 may be de-scaled by reversing the polarity of one or both of the stacks 110, 150.
  • the chambers that act as the RED concentrate chambers 162 in a forward polarity are used as the RED diluent chambers 164 in a reverse polarity
  • the chambers that act as the RED diluent chambers 164 in the forward polarity are used as the RED concentrate chambers 162 in the reverse polarity.
  • the chambers that act as the EDR product chambers 112 in the forward polarity are used as the EDR diluent chambers 114 in the reverse polarity, and the chambers that act as the EDR diluent chambers 114 in the forward polarity are used as the EDR product chambers 112 in the reverse polarity.
  • the electrode that acts as the anode 103 in the forward polarity acts as the cathode 104 in the reverse polarity
  • the electrode that acts as the cathode 104 in the forward polarity acts as the anode 103 in the reverse polarity.
  • Reversible electrodes made of materials such as titanium coated with a noble metal, such as platinum, strontium, rubidium or a mixture of any of these noble metals, are used to facilitate reversibility.
  • Figure 1 depicts stacks 110, 150 in which the anion and cation exchange membranes 151, 153 and the anode 103 and cathode 104 are linear
  • the membranes 151, 153 and the anode 103 and cathode 104 may be curved such that the stacks 110, 150 take on a wound spiral shape.
  • the stacks 110, 150 may also be manufactured in the form of other shapes (not depicted), so long as ionic current is able to flow through the stacks 1 10, 150.
  • the CDE plant 201 (“concentration difference energy plant” or “CDE plant” 201) that is able to desalinate saltwater while generating electricity by exploiting concentration difference energy using the RED stack 150.
  • the CDE plant 201 includes a water source 202, which can be the ocean or a brackish water supply, for example.
  • the water source 202 is fluidly coupled to a pre-treatment system 206 that treats the saltwater prior to desalination by removing debris, suspended solids, and organic matter that can foul or plug the equipment used in the CDE plant 201.
  • the pre-treatment system 206 is fluidly coupled to and sends treated saltwater to an EDR product feed vessel 208, an RED diluent vessel 210, and an EDR diluent vessel 212, which respectively store the product feed, and RED diluent, and the EDR diluent for use in the stacks 110, 150 that form part of the CDE plant 201.
  • the EDR diluent vessel 212 and product feed vessel 208 are fluidly coupled to the EDR stack 110, while the RED diluent vessel 210 is fluidly coupled to the RED stack 150.
  • an RED concentrate vessel 214 which stores the RED concentrate for circulation through the RED stack 150.
  • the product feed and EDR diluent are pumped through the EDR stack 1 10 and the RED concentrate and RED diluent are pumped through the RED stack 150.
  • the product feed in the EDR product chambers 112 is maintained at a higher pressure than the EDR diluent in the EDR diluent chambers 114 such that if leakage occurs, the product flows into the EDR diluent chambers 1 14 and not vice-versa. Consequently, if leakage occurs the product is not contaminated.
  • the RED diluent in the RED diluent chambers 164 is maintained at a higher pressure than the RED concentrate in the RED concentrate chambers 162 such that if leakage occurs, the RED diluent flows into the RED concentrate chambers 162 and not vice- versa.
  • This is beneficial in the embodiment of Figure 2, as some of the RED diluent may be routed to a reconcentrator 230 (as discussed in more detail below) and used to generate the RED concentrate after exiting the RED stack 150, whereas the RED concentrate exiting the RED stack 150 is not used to generate the RED diluent.
  • the EDR diluent that exits the EDR stack 110 is routed to any or all of three destinations: back to the EDR diluent vessel 212 via a control valve 234; to the RED diluent vessel 210 via a control valve 236; and back to the water source 202 via a check valve 223.
  • the proportion of the EDR diluent that is diverted to each of these three destinations can be determined by plant designers and operators in order to satisfy energy efficiency, product volume relative to intake water volume (recovery ratio), and discharge concentration requirements.
  • the RED diluent that exits the RED stack 150 is routed to any or all of four destinations: to the reconcentrator 230 that is used to generate the RED concentrate via a control valve 238; to the EDR diluent vessel 212 via a control valve 240; back to the RED diluent vessel 210 via a control valve 237; and back to the water source 202 via a check valve 222.
  • the proportion of the RED diluent sent to any of these destinations can be determined by plant designers and operators in order to satisfy energy efficiency, recovery ratio, and discharge concentration requirements.
  • EDR and RED diluent when used EDR and RED diluent is recycled to the EDR and RED vessels 212, 210, energy efficiency of the CDE plant 201 decreases because the concentration differences within the stacks 1 10, 150 decrease, but recovery ratio increases since less water is taken from the water source 202. Plant designers and operators can balance the benefits offered by reduced saltwater intake and pre-treatment against reduced energy efficiency by adjusting the concentration within the EDR and RED vessels 212, 210.
  • salt that the RED concentrate loses while passing through the RED stack 150 can be replaced; accumulation of precipitated salt in the RED diluent vessel 210 can, to a certain degree, be prevented; and the concentration of the RED diluent in the RED diluent vessel 210 can more easily be kept relatively low.
  • the RED concentrate exiting the RED stack 150 is recycled either directly back to the RED concentrate vessel 214, or back to the RED concentrate vessel 214 via the reconcentrator 230 and control valves 239, 243.
  • the reconcentrator 230 evaporates water to air to maintain or increase the concentration of the RED concentrate. In so doing, the reconcentrator 230 also removes water from the used RED diluent that is diverted to the reconcentrator 230 via the control valve 238.
  • Exemplary evaporative reconcentrators include evaporative ponds, evaporative spray ponds, natural draft evaporative towers, forced draft evaporative towers, and other suitable devices that can evaporate water from a solution to air.
  • the reconcentrator 230 can include an apparatus for capturing and condensing water vapor from the relatively humid air that results from evaporation.
  • This apparatus can be, for example, a cool surface downwind of an evaporative spray pond, or a cool condensing surface internal to an evaporative tower that collects condensed water but that does not allow it to mix with the RED concentrate within the tower.
  • the RED concentrate stored in the RED concentrate vessel 214 can exit the RED concentrate vessel 214 not only by being pumped through the RED stack 150, but by being sent to the reconcentrator 230 via a control valve 241 and by being periodically discharged through a discharge line via a control valve 231 to prevent salt from accumulating within the RED concentrate vessel 214.
  • control valves 241, 243 balance flow rates into and out of the RED concentrate vessel 214 in order to maintain the fluid volume and temperature of the reconcentrator 230 at levels set by the plant operator.
  • the RED concentrate that is periodically discharged via the control valve 231 can be harvested for commercial use using known methods for extracting solid salt from concentrated brines.
  • the EDR diluent vessel 212 acts as an EDR diluent mixer. As mentioned above, the EDR diluent vessel 212 is fluidly coupled, via piping, to the pre-treatment system 206, to the EDR stack 1 10 to receive the EDR diluent that has been used in the EDR stack 1 10, and to the RED stack 150 to receive the RED diluent that has been used in the RED stack 150.
  • the system operator will want to maintain the EDR diluent stored within the EDR diluent vessel 212 at a certain concentration (“EDR diluent threshold") that is above that of the saltwater obtained via the pre-treatment system 206, and below the concentrations of the used EDR and RED diluents.
  • EDR diluent threshold a certain concentration
  • the system operator can accomplish this by controlling the proportion at which used EDR diluent, used RED diluent, and saltwater from the pre-treatment system 206 enter the EDR diluent vessel 212 such that the resulting mixture has a concentration that equals the EDR diluent threshold.
  • the RED diluent vessel 210 is fluidly coupled via piping to the pre-treatment system 206, to the EDR stack 1 10 to receive used EDR diluent, and to the RED stack 150 to receive used RED diluent.
  • the system operator will want to maintain the RED diluent stored within the RED diluent vessel 210 at a certain concentration (“RED diluent threshold") that is above that of the saltwater obtained via the pre-treatment system 206, and far below the concentration of the RED concentrate so as to facilitate electricity generation.
  • the system operator may want to increase the recovery ratio of the system; i.e., the amount of product produced compared to the amount of saltwater drawn from the water source 202. If this is the goal, the RED diluent can be maintained at a concentration higher than that of the EDR diluent through recirculation of the RED diluent exiting the RED stack 150 back to the RED diluent vessel 210 through the control valve 237. This recirculation reduces the amount of make-up saltwater drawn from the pre-treatment system 206, which accordingly reduces the amount of saltwater drawn from the water source 202 and increases the recovery ratio.
  • the system operator can control the concentration of the RED diluent by controlling the proportion at which used RED diluent, used EDR diluent, and saltwater from the pre-treatment system 206 enter the RED diluent vessel 210 such that the resulting mixture has a concentration that equals the RED diluent threshold.
  • the mixers may simply be a series of pipes carrying different fluids meeting at a common junction; the junction may include a mixing element that introduce "swirl” (i.e.: turbulent flow) to the flowing fluids such that the fluids mix downstream of the junction.
  • swirl i.e.: turbulent flow
  • the CDE plant 201 is able to store low grade thermal energy, such as solar energy, in the form of concentrated saltwater; this stored solar energy is harnessed to generate electricity using the RED stack 150 which, in turn, is used to desalinate the product feed in the EDR stack 110.
  • Low grade thermal energy include waste heat (e.g.: from a power plant); exemplary waste heat is between 30 to 80 °C.
  • waste heat e.g.: from a power plant
  • exemplary waste heat is between 30 to 80 °C.
  • Many industries that require desalinated water tend to have low grade heat sources available.
  • low grade heat may be extracted from solar thermal sources such as black bottomed ponds or solar water heaters.
  • the CDE plant 201 depicted in Figure 2 uses only one of the EDR stacks 110, in alternative embodiments (not depicted) more than one of the EDR stacks 1 10 can be used.
  • several of the EDR stacks 1 10 can be fluidly coupled in series, in which case the product feed is partially desalinated in each of the EDR stacks 110.
  • Using several of the EDR stacks 110 in series to desalinate the product feed facilitates a higher reduction in the salt concentration of the product feed.
  • several of the EDR stacks 1 10 may be fluidly coupled together in parallel, which facilitates desalination of a greater volume of the product feed.
  • the CDE plant 201 may be operated in batch mode, in which case discrete batches of product are produced by circulating all or a portion of the product that is output from the EDR stack 110 back to the product feed vessel 208 until the solution in the product feed vessel 208 has the desired salinity content.
  • Figure 3 there is shown a schematic view of a network 301 of multiple RED stacks 150a,b,c and EDR stacks 110a,b,c electrically coupled together such that any one or more of the RED stacks 150a,b,c can be electrically coupled to any one or more of the EDR stacks 1 10a,b,c via an electrical bus 303 and switches 302a-h.
  • the network 301 may be incorporated into the CDE plant 201 in place of the single RED and EDR stacks 150,1 10 depicted in Figure 2.
  • two of the RED stacks 150a,b may power the three EDR stacks 110a,b,c by closing the switches 302a,b,c,d,e,f,h and by opening the switch 302g.
  • This may be done, for example, to set the net impedance of the active RED stacks to be the complex conjugate of the active EDR stacks, or to isolate the RED stack 150c in order to perform maintenance on it.
  • setting the impedance of the active RED stacks to be complex conjugate of the EDR stacks will result in a relatively high amount of power being transferred from the RED stacks to the EDR stacks.
  • the RED stacks 150a,b,c and EDR stacks 110a,b,c may be electrically coupled to a power grid in the form of an AC power system 390 via the electrical bus 303 and one of a controllable inverter 360 and a controllable rectifier 370.
  • the inverter 360 converts DC to AC
  • the rectifier 370 converts AC to DC.
  • switches 302i,k can be closed and switches 302j,l can be opened, and excess electricity can be converted into AC by the inverter 360 and transmitted to the AC power system 390.
  • the switches 302i,k can be opened and the switches 302j,l can be closed, and electricity can be purchased from the AC power system 390, rectified into DC by the rectifier 370, and used by the EDR stacks 110a,b,c.
  • the RED stacks 150a,b,c and EDR stacks 110a,b,c may be electrically coupled to a DC power system. In such an alternative embodiment, the rectifier 370 and inverter 360 are not required.
  • a plant operator can use any or all of the RED stacks 150a,b,c and EDR stacks 110a,b,c to generate a relatively high amount of electricity for delivery and sale to the AC power system 390 for sale at the cost of the ability to desalinate saltwater. This can be accomplished by operating both the RED stacks 150a,b,c and the EDR stacks 110a,b,c as RED stacks. Alternatively, the plant operator can use any or all of the RED stacks 150a,b,c and EDR stacks 110a,b,c to desalinate a relatively high volume of product feed using electricity purchased from the AC power system 390.
  • the decision of whether to produce electricity for sale or to purchase electricity for desalination will be made based on several factors. Examples of these factors include: water volume delivery need (as delivery need increases, more electricity is utilized for desalination); power system needs (if the AC power system 390 requires more electricity, more electricity can be generated for delivery to the AC power system 390); a relative increase in demand for or the price of water relative to demand for or the price of power, which favors increasing the rate at which saltwater is desalinated by purchasing power and using the power for desalination; and a relative increase in demand for or the price of power relative to demand for or the price of water, which favors increasing the rate at which electricity is generated and sold to the AC power system 390.
  • all of the switches 302a-h can be closed, the switches 302 i,k can be opened, the switches 302 j,l can be closed, and all of the stacks 150a,b,c and 110a,b,c can be operated as EDR stacks and used to desalinate product feed by using the electricity from the AC power system 190 that is rectified by the rectifier 370.
  • the RED stacks 150a,b,c can be operated as EDR stacks and used to desalinate product feed by replacing the RED concentrate and RED diluent with product feed and EDR diluent, and by applying a sufficient voltage across the stacks 150a,b,c.
  • the EDR stacks 1 10a,b,c can be operated as RED stacks and used to generate electricity by replacing the product feed and EDR diluent with RED concentrate and RED diluent.
  • operating in the manner as described above allows the plant operator to balance product production and electricity generation in accordance with market conditions.
  • water can be stored more readily than electricity, by using the RED stacks 150,a,b,c and the EDR stacks 110a,b,c to produce product during periods of low cost electricity, electricity can effectively be stored as product.
  • the network 301 may be used to store electrical energy when electricity is relatively inexpensive (“off-peak times") and used to produce electrical energy when electricity is relatively expensive (“peak times").
  • off-peak times electrical energy when electricity is relatively inexpensive
  • peak times electrical energy when electricity is relatively expensive
  • RED concentrate production can be increased by diverting a portion of the RED diluent to the reconcentrator 230, and, conversely, during peak times electricity production can subsequently be increased using the RED stacks.
  • process piping that enables all of the stacks 110a,b,c and 150a,b,c to be used to produce RED concentrate from one or both of the RED and EDR diluents can be added as a way to produce RED concentrate in place of or in addition to running the reconcentrator 230.
  • a combined desalination plant 401 that uses brine discharge from a first desalination plant 402 to replenish the RED concentrate used in a second desalination plant, the CDE plant 201, that incorporates the RED stack 150 and the EDR stack 110.
  • the first desalination plant 402 may utilize technology such as reverse osmosis, multi-stage flash (MSF), multiple effect distillation (MED), electrodialysis, or vapor recompression.
  • the first desalination plant 402 is fluidly coupled to the water source 202 via a flow control mechanism such as a control valve 405; the first desalination plant 402 obtains saltwater from the water source and produces freshwater that it outputs via a freshwater outlet 406 and the brine discharge, which it outputs via a brine discharge outlet 408.
  • a flow control mechanism such as a control valve 405
  • the first desalination plant 402 obtains saltwater from the water source and produces freshwater that it outputs via a freshwater outlet 406 and the brine discharge, which it outputs via a brine discharge outlet 408.
  • the saltwater input to the first desalination plant 402 is about 3.5% salt by mass
  • the freshwater output from the first desalination plant 402 is typically about 0.04% salt by mass
  • the brine discharge is typically between about 6 to 10% salt by mass, more particularly is between about 7 to 8% salt by mass, and more particularly still about 7.5% salt by mass.
  • the brine discharge output by the first desalination plant 402 is diverted to any or all of three destinations: back to the water source 202 via a check valve 412; directly to the RED concentrate vessel 214 via control valve 424; and to the reconcentrator 230 via control valve 420.
  • the brine discharge By diverting the brine discharge to either of the reconcentrator 230 and the RED concentrate vessel 214, the amount of evaporation that the reconcentrator 230 needs to perform in order to generate the RED concentrate can be reduced. Beneficially, this can make use of the brine discharge, which is a waste product that the first desalination plant 402 outputs, while also reducing the energy that the reconcentrator 230 uses.
  • EDR diluent vessel 212 3.5 to 5% salt by mass (concentration increases with increased recirculation through the valve 234);
  • the brine discharge may also contain thermal energy, as occurs when the first desalination plant 402 is a thermal desalination plant such as an MSF or MED plant or if the brine discharge passes through a heat exchanger (not shown) that accepts heat from another energy source (e.g.: waste heat from a process plant) prior to entering the reconcentrator 230.
  • the saltwater discharged from the CDE plant 201 can be adjusted to have a higher or lower concentration than the brine discharge from the first desalination plant 402; this is achieved by adjusting the concentration of the EDR diluent by modulating the valves 234, 240, 236, 237 as described above.
  • the saltwater discharged from the CDE plant 201 has a concentration equal to the average, weighted by volume, of the concentration of the saltwater discharged via the check valves 222, 223; used RED diluent is discharged via the check valve 222, while used EDR diluent is discharged via the check valve 223.
  • the combined desalination plant 401 mitigates concerns related to discharging relatively high concentration saltwater into the environment.
  • the combined desalination plant 401 can be configured to output a higher concentration discharge than the brine discharged from the first desalination plant 402 alone, in which case overall brine volume is decreased.
  • the combined desalination plant 401 can accomplish this by decreasing the amount of make-up saltwater channelled from the water source 202 to the pre-treatment system 206 through control valve 407, and correspondingly increasing the rate at which used RED and EDR diluent is recycled back the RED and EDR diluent vessels 210, 212, respectively, through the control valves 237, 234.
  • locating the CDE plant 201 near the first desalination plant 402 facilitates cost reductions by allowing the two plants 201, 402 to share infrastructure such as post-treatment systems and water storage or distribution systems.
  • Other exemplary shared infrastructure includes saltwater intakes, saltwater outlets, pre-treatment systems, post-treatment systems, power lines, water mains, control systems, and operations staff.
  • ZLD plant a zero liquid discharge plant
  • the exemplary ZLD plant 501 depicted in Figure 5 is substantially similar to the CDE plant 201 depicted in Figure 2, with certain exceptions.
  • One exception is that the RED diluent vessel 210 does not receive water directly from the pre-treatment system 206. No water from the pre- treatment system 206 is directly added to the RED diluent vessel 210 because doing so could dilute the RED diluent such that liquid may have to be discharged from the plant 501 during operation, which is undesirable in a ZLD plant.
  • EDR diluent vessel 212 does not receive any of the used RED diluent. Adding used RED diluent to the EDR diluent vessel 212 would increase the concentration of the EDR diluent, thereby decreasing the concentration gradient between the EDR concentrate and EDR diluent and increasing the energy required to desalinate the product.
  • the concentration of the RED diluent relatively high by not adding water to the RED diluent vessel 210 decreases the amount of electricity that the RED stack 150 generates; beneficially, however, keeping the concentration of the EDR diluent relatively low by not diverting used RED diluent to the EDR diluent vessel 208 decreases the amount of electricity required for desalination.
  • one or both of used RED diluent and water from the pre-treatment system 206 may be diverted to the EDR diluent vessel 208 and the RED diluent vessel 210, respectively.
  • a third exception is that the discharge line and the control valve 231 that are used to discharge RED concentrate from the RED concentrate vessel 214 in the plant 201 are not present. Instead, as discussed in further detail below, a second reconcentrator 506 (“zero liquid discharge reconcentrator” or “ZLD reconcentrator”) is fluidly coupled to the output of the reconcentrator 230 via a control valve 504. By controlling the degree to which the control valves 504, 243 are opened, the fluid leaving the reconcentrator 230 can be divided between the RED concentrate vessel 214 and the ZLD reconcentrator 506, as desired.
  • a fourth exception, related to the ZLD reconcentrator 506, is that neither the used RED diluent nor the used EDR diluent are discharged directly back to the water source 202.
  • the RED stack 150 During normal operation of the ZLD plant 501, the RED stack 150 generates electricity and the EDR stack 110 desalinates the product feed, as described above.
  • the concentration of the RED diluent stored in the RED diluent vessel 210 is maintained by mixing together used EDR diluent (which tends to lower the concentration of the RED diluent stored in the RED diluent vessel 210) and used RED diluent (which tends to raise the concentration of the RED diluent stored in the RED diluent vessel 210).
  • the concentration of the EDR diluent stored in the EDR diluent vessel 212 is maintained by mixing together treated water from the water source 202 (which tends to lower the concentration of the EDR diluent stored in the EDR diluent vessel 212) and used EDR diluent (which tends to raise the concentration of the EDR diluent stored in the EDR diluent vessel 212).
  • Used RED concentrate is routed to the reconcentrator 230 where the concentration of the used RED concentrate is increased through evaporation.
  • the used RED concentrate can be routed to the ZLD reconcentrator 506 where the concentration of the used RED concentrate is further increased, and then to a salt harvesting device in which substantially all the water can be evaporated from the RED concentrate and consequently from which can be harvested precipitated salts; an exemplary salt harvesting device is a sump 508.
  • a salt harvesting device is a sump 508.
  • the reconcentrator 230 may increase the salt concentration of the RED concentrate to less than 18% and then transfer the RED concentrate to the ZLD reconcentrator 506, which increases the concentration of the concentrate to above 18%, and more particularly to concentrations higher than about 24% to achieve salt crystallization. Precipitated salt can then be removed from the sump 508. Beneficially, this lowers the risk that salt precipitation occurs anywhere in the CDE plant 201 aside from the ZLD reconcentrator 506 and the sump 508, and allows salt harvesting to occur in a controlled fashion.
  • either of the reconcentrator 230 and the ZLD reconcentrator 506 may output RED concentrate to an alternative type of salt harvesting device.
  • other exemplary salt harvesting devices are similar to evaporative reconcentrators - evaporative ponds, evaporative spray ponds, natural draft evaporative towers, and forced draft evaporative towers - with the ability to shut down the reconcentrator and collect the precipitated salts.
  • a single one of the salt harvesting devices may be operated in batch mode in combination with sufficient RED concentrate storage volume, or many of the salt harvesting devices may be operated in batch mode at various concentrations approaching precipitation. Salt harvesting is beneficial in that harvested salt can be sold and not discharged into the environment, which may make obtaining regulatory approval for plant construction easier.
  • the ZLD plant 501 can alternatively produce a low volume, high concentration saltwater discharge of 12% salt by mass or greater, and this high concentration saltwater discharge can be discharged back to the water source 202 or otherwise stored or transported away for further treatment.
  • this high concentration saltwater discharge can be discharged back to the water source 202 or otherwise stored or transported away for further treatment.
  • the ZLD plant 501 can be used, for example, to desalinate underground saline aquifers. When ocean water is desalinated, the resulting brine is typically returned to the ocean. When an underground aquifer is desalinated, the brine may be sent back down to the saltwater aquifer; however, this increases the salt concentration of the aquifer, making further desalination from the same aquifer more difficult.
  • the ZLD plant 501 allows saltwater to be desalinated without producing brine discharge. Being able to reduce the volume of saltwater in the aquifer without returning the brine to the aquifer also beneficially creates storage space in the aquifer into which carbon dioxide produced by an external process can be stored, for example.
  • FIG. 6 there is depicted another embodiment of the combined desalination plant 401 that includes the first desalination plant 602 fluidly coupled to the ZLD plant 501 such that brine discharged from the first desalination plant 602 is used as product feed in the CDE plant 201.
  • brine is not directly channelled from the first desalination plant 602 into the reconcentrator 230 of the ZLD plant 501.
  • the ZLD plant 501 uses the brine discharged from the first desalination plant 602 instead of saltwater obtained from the water source 202.
  • the ZLD plant 501 partially desalinates the brine in that it reduces the salt content of the brine, but not to levels suitable for potable, drinking water.
  • the ZLD plant 501 and the first desalination plant 602 are fluidly coupled such that partially desalinated brine leaving the ZLD plant 501 is returned to the first desalination plant 602 for further desalination. Following this further desalination, the first desalination plant 602 outputs the product to the post-treatment system 218 and to the product vessel 220.
  • partially desalinated brine refers to brine that has been desalinated, but not to the extent as ultimately desired by the plant operator.
  • partial desalination refers to desalinating the brine discharged by the first desalination plant 602 to a level above 0.04%.
  • partial desalination may involve desalinating the brine discharged by the first desalination plant 401 to a concentration roughly equal to that of the water source 202, which is typically around 3.5% salt by mass.
  • the combined desalination plant 401 of Figure 6 is beneficial in that it results in a higher recovery ratio than the first desalination plant 602 is capable of alone.
  • the ZLD plant 501 can perform de-scaling by reversing ionic current, as discussed above. Furthermore, the ZLD plant 501 can remove the larger ionic species that are primarily responsible for scaling, such as Ca 2+ or S0 4 2" , efficiently, which is beneficial when partially desalinated brine is returned to the first desalination plant 602 for further desalination.
  • the first desalination plant 602 may be similarly coupled to the CDE plant 201. That is, brine discharged from the first desalination plant 602 may be used as product feed and partially desalinated by the CDE plant 201 depicted in Figure 2, with the partially desalinated brine being returned to the first desalination plant 602 for additional desalination.
  • Any of the foregoing methods that are described as being used in conjunction with any of the foregoing stacks, systems, and plants can be stored on a computer readable medium for execution by a any suitable controller, such as a processor, microcontroller, programmable logic controller, field programmable gate array, or can be implemented in hardware using, for example, an application-specific integrated circuit.
  • exemplary computer readable media include disc-based media such as CD-ROMs and DVDs, magnetic media such as hard drives and other forms of magnetic disk storage, semiconductor based media such as flash media, random access memory, and read only memory.
  • a control system (not shown), communicatively coupled to the components in the foregoing plants and systems, may access and execute the methods stored on the computer readable medium so as to automatically control the operation of any of the foregoing plants and systems.

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Abstract

La présente invention concerne des techniques, des procédés et des systèmes combinés de dessalement de l'eau salée et de production d'électricité. Une pile d'électrodialyse inverse (RED) est utilisée pour la production d'électricité et l'électricité ainsi produite est utilisée pour dessaler l'eau salée dans une pile à inversion d'électrodialyse (EDR). Comme la pile de RED repose sur le principe d'une différence de concentration entre deux fluides ioniques pour produire de l'électricité, une unité de dessalement intégrant des piles de RED et d'EDR comme décrit ici est désignée comme « centrale électrique à différence de concentration ». La saumure évacuée d'une première unité de dessalement, par exemple d'une unité à osmose inverse, peut être partiellement dessalée par la centrale électrique à différence de concentration et la saumure partiellement dessalée peut, éventuellement, être renvoyée vers la première unité de dessalement pour un nouveau dessalement. Cela peut présenter plusieurs avantages. Par exemple, la centrale électrique à différence de concentration peut éliminer des espèces ioniques de grande taille qui, si elles ne l'étaient pas, pourraient être à l'origine d'un entartrage de la première unité de dessalement.
PCT/CA2010/001718 2009-10-30 2010-10-25 Procédé et système combinés de dessalement de l'eau salée et de production d'électricité WO2011050473A1 (fr)

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PCT/CA2010/000537 WO2010115287A1 (fr) 2009-04-09 2010-04-08 Procédé et système de dessalement d'eau salée à l'aide d'une énergie de différence de concentration

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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102610835A (zh) * 2012-03-19 2012-07-25 上海海事大学 一种利用盐差能反电渗析的发电装置
US20130087501A1 (en) * 2011-10-06 2013-04-11 General Electric Compay Seawater desalination process
WO2014080188A1 (fr) * 2012-11-20 2014-05-30 Fujifilm Manufacturing Europe Bv Production d'électricité
WO2014110358A1 (fr) * 2013-01-11 2014-07-17 The General Hospital Corporation Système et procédé de génération d'électricité à partir de la salinisation d'eau douce
US20140255813A1 (en) * 2013-03-11 2014-09-11 BlueCell Energy, LLC Energy generation and storage using electro-separation methods and devices
ITRM20130537A1 (it) * 2013-10-03 2015-04-04 Univ Palermo Metodo di trattamento di acque inquinate e la contestuale generazione di energia elettrica
CN104876372A (zh) * 2014-02-28 2015-09-02 温州大学 一种自脱盐系统
US20150357651A1 (en) * 2014-06-10 2015-12-10 Magna Imperio Systems Corp. Apparatus and methods for treating water and generating electrical power
CN105236631A (zh) * 2015-11-27 2016-01-13 福建创源环保有限公司 一种基于多电极多隔膜电解槽的高盐工业废水处理方法
CN105293642A (zh) * 2015-11-27 2016-02-03 福建创源环保有限公司 一种处理高盐工业废水的多电极多隔膜电解槽
US9322723B2 (en) 2012-07-10 2016-04-26 General Electric Company Energy harvesting survey apparatus and method of detecting thermal energy
CN106977020A (zh) * 2016-01-15 2017-07-25 贾德彬 苦咸水处理系统
CN108601935A (zh) * 2016-01-05 2018-09-28 生物传感器硏究所 安装在面膜上的装置以及包括该装置的面膜和成套工具
WO2019148035A1 (fr) * 2018-01-26 2019-08-01 Walter Jennings John Système intégré de dessalement et de production d'énergie
US10604426B2 (en) 2016-12-23 2020-03-31 Magna Imperio Systems Corp. High efficiency electrochemical desalination system that incorporates participating electrodes
EP3643683A4 (fr) * 2017-12-11 2021-05-26 Korea Institute of Energy Research Appareil de production d'énergie hybride à gradient de salinité/énergie solaire et système de dessalement l'utilisant
GB2589649A (en) * 2020-04-17 2021-06-09 Atom Industries Int Ltd Apparatus and method for production of hydrogen gas
EP3708544A4 (fr) * 2017-11-06 2021-07-14 Korea Institute of Energy Research Appareil de génération d'énergie hybride et procédé permettant de produire simultanément de l'électricité et de la déionisation
IL264680B (en) * 2018-02-07 2022-09-01 Palo Alto Res Ct Inc Electrochemical desalination system
US11502322B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell with heat pump
US11502323B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell and methods of use thereof
US11855324B1 (en) 2022-11-15 2023-12-26 Rahul S. Nana Reverse electrodialysis or pressure-retarded osmosis cell with heat pump

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1746680A1 (fr) * 2005-07-20 2007-01-24 Vlaamse Instelling Voor Technologisch Onderzoek (Vito) Combinaison d'une installation de dessalage avec une centrale d'électricité basée sur l'électrodialyse inversée et exploitant le gradient de salinité et son utilisation
CA2649873A1 (fr) * 2008-06-24 2009-04-08 Saltworks Technologies Inc. Methode, appareillage et usine de dessalement de l'eau salee faisant appel a l'energie tiree de la difference de concentration
CA2699174A1 (fr) * 2009-04-09 2010-10-09 Saltworks Technologies Inc. Methode et dispositif de dessalement de l'eau salee reposant sur l'energie associee a la difference de concentration

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1746680A1 (fr) * 2005-07-20 2007-01-24 Vlaamse Instelling Voor Technologisch Onderzoek (Vito) Combinaison d'une installation de dessalage avec une centrale d'électricité basée sur l'électrodialyse inversée et exploitant le gradient de salinité et son utilisation
CA2649873A1 (fr) * 2008-06-24 2009-04-08 Saltworks Technologies Inc. Methode, appareillage et usine de dessalement de l'eau salee faisant appel a l'energie tiree de la difference de concentration
CA2699174A1 (fr) * 2009-04-09 2010-10-09 Saltworks Technologies Inc. Methode et dispositif de dessalement de l'eau salee reposant sur l'energie associee a la difference de concentration

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130087501A1 (en) * 2011-10-06 2013-04-11 General Electric Compay Seawater desalination process
AU2012319064B2 (en) * 2011-10-06 2016-09-08 Bl Technologies, Inc. Seawater desalination process and apparatus
US9382135B2 (en) 2011-10-06 2016-07-05 General Electric Company Seawater desalination process
CN102610835A (zh) * 2012-03-19 2012-07-25 上海海事大学 一种利用盐差能反电渗析的发电装置
US9322723B2 (en) 2012-07-10 2016-04-26 General Electric Company Energy harvesting survey apparatus and method of detecting thermal energy
WO2014080188A1 (fr) * 2012-11-20 2014-05-30 Fujifilm Manufacturing Europe Bv Production d'électricité
US10177396B2 (en) 2012-11-20 2019-01-08 Fujifilm Manufacturing Europe B.V. Electricity generation
WO2014110358A1 (fr) * 2013-01-11 2014-07-17 The General Hospital Corporation Système et procédé de génération d'électricité à partir de la salinisation d'eau douce
US10084197B2 (en) 2013-01-11 2018-09-25 The General Hospital Corporation System and method of generating electricity from the salinization of freshwater
US20140255813A1 (en) * 2013-03-11 2014-09-11 BlueCell Energy, LLC Energy generation and storage using electro-separation methods and devices
ITRM20130537A1 (it) * 2013-10-03 2015-04-04 Univ Palermo Metodo di trattamento di acque inquinate e la contestuale generazione di energia elettrica
CN104876372A (zh) * 2014-02-28 2015-09-02 温州大学 一种自脱盐系统
US20150357651A1 (en) * 2014-06-10 2015-12-10 Magna Imperio Systems Corp. Apparatus and methods for treating water and generating electrical power
US9666873B2 (en) * 2014-06-10 2017-05-30 Magna Imperio Systems Corp. Apparatus and methods for treating water and generating electrical power
CN105293642A (zh) * 2015-11-27 2016-02-03 福建创源环保有限公司 一种处理高盐工业废水的多电极多隔膜电解槽
CN105236631A (zh) * 2015-11-27 2016-01-13 福建创源环保有限公司 一种基于多电极多隔膜电解槽的高盐工业废水处理方法
CN108601935A (zh) * 2016-01-05 2018-09-28 生物传感器硏究所 安装在面膜上的装置以及包括该装置的面膜和成套工具
CN106977020A (zh) * 2016-01-15 2017-07-25 贾德彬 苦咸水处理系统
CN106977020B (zh) * 2016-01-15 2023-04-18 贾德彬 苦咸水处理系统
US10604426B2 (en) 2016-12-23 2020-03-31 Magna Imperio Systems Corp. High efficiency electrochemical desalination system that incorporates participating electrodes
EP3708544A4 (fr) * 2017-11-06 2021-07-14 Korea Institute of Energy Research Appareil de génération d'énergie hybride et procédé permettant de produire simultanément de l'électricité et de la déionisation
EP3643683A4 (fr) * 2017-12-11 2021-05-26 Korea Institute of Energy Research Appareil de production d'énergie hybride à gradient de salinité/énergie solaire et système de dessalement l'utilisant
WO2019148035A1 (fr) * 2018-01-26 2019-08-01 Walter Jennings John Système intégré de dessalement et de production d'énergie
US10689266B1 (en) 2018-01-26 2020-06-23 John Walter Jennings Integrated desalination-power system
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