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WO2025010402A1 - Sustainable desalination plant and sustainable method for the desalination of water - Google Patents

Sustainable desalination plant and sustainable method for the desalination of water Download PDF

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Publication number
WO2025010402A1
WO2025010402A1 PCT/US2024/036881 US2024036881W WO2025010402A1 WO 2025010402 A1 WO2025010402 A1 WO 2025010402A1 US 2024036881 W US2024036881 W US 2024036881W WO 2025010402 A1 WO2025010402 A1 WO 2025010402A1
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WIPO (PCT)
Prior art keywords
hydroxide
calcium
combination
fluids
naci
Prior art date
Application number
PCT/US2024/036881
Other languages
French (fr)
Inventor
Alex DRAK
Tomer EFRAT
Original Assignee
IDE Americas, Inc.
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Filing date
Publication date
Application filed by IDE Americas, Inc. filed Critical IDE Americas, Inc.
Publication of WO2025010402A1 publication Critical patent/WO2025010402A1/en

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    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
    • B01D61/362—Pervaporation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • C01D1/04—Hydroxides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00—Compounds of calcium, strontium, or barium
    • C01F11/02—Oxides or hydroxides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F5/00—Compounds of magnesium
    • C01F5/14—Magnesium hydroxide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F5/00—Compounds of magnesium
    • C01F5/24—Magnesium carbonates
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F11/00—Treatment of sludge; Devices therefor
    • C02F11/18—Treatment of sludge; Devices therefor by thermal conditioning
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/04—Specific process operations in the feed stream; Feed pretreatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/12—Addition of chemical agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/26—Further operations combined with membrane separation processes
    • B01D2311/263—Chemical reaction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/26—Further operations combined with membrane separation processes
    • B01D2311/2642—Aggregation, sedimentation, flocculation, precipitation or coagulation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/025—Reverse osmosis; Hyperfiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/027—Nanofiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14—Ultrafiltration; Microfiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B01D61/52—Accessories; Auxiliary operation
    • 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
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
    • 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
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
    • 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
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • 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
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/445—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by forward osmosis
    • 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
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/448—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by pervaporation
    • 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
    • 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
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • 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
    • C02F1/68—Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water
    • 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
    • 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

Definitions

  • the present invention relates generally to a more environmentally sustainable production of desalinated water and to a sustainable desalination plant.
  • Desalination is a process that removes mineral components from sea water to provide water that is suitable for human consumption or irrigation.
  • the by-product of the desalination process is brine, a super concentrated solution.
  • a conventional seawater desalination plant delivers sea water, via an intake channel, through various pre-treatment sites such as filters before being pumped under pressure through multiple reverse osmosis passes to form desalinated product water and concentrated sea water or brine.
  • other minerals in addition to salt are removed from the water which must be re-introduced to provide an acceptable product water and therefore the water is also subjected to posttreatments, such as pH adjustment and the addition of minerals such as magnesium before being held in a holding tank for later consumption.
  • the brine may be discharged back into the sea via a discharge channel or subjected to a further desalination process to create additional product water.
  • Drinking water that leaves the desalination plant must have a certain concentration of minerals.
  • the required minerals are purchased, delivered to the plant, and added to the reverse osmosis product in the final remineralization treatment stage of the desalination plant.
  • the purchase and delivery of the chemicals make the operation problematic especially in places where those chemicals are unavailable.
  • delivery / transportation of chemicals affects the environment, increasing the emission of carbon dioxide to the atmosphere. It is desirable to be able to produce the required chemicals onsite as this would significantly improve the sustainability of the desalination plant. It is an object of the present invention to provide an improved desalination process and system that aims to address this issue.
  • a method of treating fluids comprising: feeding at least a portion of said fluids through at least one reactor for the removal of carbonates-based chemicals by precipitation; regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and utilizing at least a portion of at least one selected from a group consisting of said calcium based chemical and carbon dioxide and any combination thereof, to remineralize said fluids; thereby treating the same.
  • the method may treat fluids selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
  • the reactor may contain calcium hydroxide (CafOH ) for the precipitation of calcium-based chemicals.
  • CafOH calcium hydroxide
  • CafOH calcium hydroxide
  • CaCOs calcium carbonate
  • feeding at least a portion of said fluids through at least one reactor containing calcium hydroxide (Ca(OH)2) increases the pH of said fluids to at least pH 8.3.
  • Ca(OH)2 calcium hydroxide
  • the fluids comprise seawater and the method further comprises the step of desalinating said seawater.
  • the method may include the additional step of delivering said seawater to at least one pass comprising at least one reverse osmosis membrane to produce permeate water and brine.
  • the regeneration step produces a calcium-based chemical selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof.
  • the regeneration step may comprise the steps of: a. at least partially dissolving said calcium carbonate; and, b. at least partially precipitating calcium-hydroxide.
  • the said step of dissolving said calcium-based chemical is preferably performed by adding at least one acid.
  • Said acid may be selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof.
  • the acid is hydrochloric acid (HCI) and its addition results in the generation of calcium chloride (CaCI) and carbon dioxide gas, (CO2).
  • HCI hydrochloric acid
  • CaCI calcium chloride
  • CO2 carbon dioxide gas
  • Said carbon dioxide gas, (CO2) is preferably generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas, CO2, extraction method.
  • At least a portion of the carbon dioxide is used in a post treatment process for remineralization of said fluids.
  • the step of at least partially precipitating calcium-hydroxide is preferably performed by increasing the pH to a level of at least 10, for example by the addition of sodium hydroxide (NaOH), to result in sodium chloride (NaCI) and calcium hydroxide (Ca(OH)2).
  • the method may further comprise the additional step of regenerating sodium hydroxide (NaOH).
  • Said step of regeneration of sodium hydroxide may be performed by feeding said sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM, preferably wherein said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
  • the step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
  • NaCI sodium chloride
  • HCI hydrochloric acid
  • at least a portion of the calcium hydroxide formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process; (c) any combination thereof.
  • the method of treating fluids according to the first aspect of the invention may also precipitate magnesium hydroxide during the step of feeding at least a portion of said fluids through at least one reactor containing calcium hydroxide (CafOH ).
  • the method may further comprise the step of regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
  • the step of regenerating at least some of the magnesium hydroxide precipitant may comprise steps of: a. at least partially dissolving said magnesium hydroxide; and, b. at least partially precipitating magnesium-hydroxide.
  • said step of dissolving said magnesium hydroxide is performed by adding at least one acid, more preferably wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof. It is preferable for the addition of hydrochloric acid (HCI), to result in the generation of magnesium chloride (MgCk).
  • HCI hydrochloric acid
  • MgCk magnesium chloride
  • said step of at least partially precipitating magnesium-hydroxide is performed by increasing the pH to a level of at least 8, more preferably at least 10.
  • the increase in pH is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and magnesium hydroxide (MgOHz).
  • the method may further comprise the step of regeneration of sodium hydroxide (NaOH).
  • Said step of regeneration of sodium hydroxide may be performed by feeding said sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM.
  • Said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
  • said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
  • At least a portion of the magnesium hydroxide formed by regeneration is at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process; (c) any combination thereof.
  • the method may further comprise adding at least a portion of the regenerated magnesium- based chemical to the permeate to produce product water.
  • the step of feeding at least a portion of water through the at least one reactor containing calcium hydroxide Ca(OH)2 according to the method of the first aspect of the invention also precipitates magnesium hydroxide; and the process further comprises the steps of (i) regenerating at least some of the calcium carbonate and magnesium hydroxide precipitants to produce a calcium- based chemical, a magnesium-based chemical and carbon dioxide; and, (ii) mixing at least some of the regenerated chemicals and carbon dioxide with the permeate product water to produce drinking water.
  • the method according to the first aspect of the present invention preferably excludes a calcium carbonate contactor in the post-treatment of the permeate water.
  • the method may further comprise the optional step of utilizing nanofiltration to generate a solution comprising at sodium chloride (NaCI) and sodium sulfate (NazSC ), and any combination thereof; from at least one selected from a group consisting of seawater, brine and any combination thereof.
  • the method may further comprise a step of feeding said solution comprising at least one of sodium chloride (NaCI), and sodium sulphate (Na2SO 4 ) and any combination thereof, through at least one electrodialysis bipolar membranes EDBM to regenerate sodium hydroxide (NaOH), hydrochloric acid (HCI), and sulfuric acid (H2SO4) and any combination thereof.
  • a second aspect of the present invention provide a self-sustainable system for treating fluids, the system comprising: at least one conduit for delivering at least a portion of fluids to at least one reactor for the removal of at least one carbonates-based chemical by precipitation; at least one regeneration module for regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and at least one remineralization module utilizing at least a portion of at least one selected from a group consisting of said calcium based-chemical and carbon dioxide and any combination thereof, to remineralize said fluids.
  • the fluids are selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
  • the at least one reactor contains calcium hydroxide (CafOH ) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO 3 ), more preferably wherein the reactor contains calcium hydroxide (Ca(OH)2) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO 3 ), according to the following equation: Ca(OH)2 + Ca(HCO 3 ) 2 --> 2CaCO 3 + 2H 2 O.
  • the system further comprises at least one conduit for introducing calcium hydroxide (Ca(OH)2) into the at least one reactor.
  • Ca(OH)2 calcium hydroxide
  • the fluids are seawater; further wherein said system additionally comprises at least one reverse osmosis pass comprising at least one reverse osmosis membrane.
  • the regeneration module of the system produces a calcium-based chemical selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof.
  • Said regeneration module of the calcium carbonate to said calcium-based chemical may comprise: a. at least one module for dissolving at least partially said calcium carbonate; and, b. at least one module for precipitating at least partially calcium-hydroxide.
  • Said module for dissolving said calcium-based chemical may comprise at least one conduit for introducing acid into the same, preferably wherein the acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO 4 ),and any combination thereof.
  • HCI hydrochloric acid
  • H2SO 4 sulfuric acid
  • the conduit introduces hydrochloric acid (HCI), to result in the generation of calcium chloride (CaCL), and carbon dioxide gas (CO2).
  • HCI hydrochloric acid
  • CO2 carbon dioxide gas
  • the carbon dioxide gas (CO2) may be generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas (CO2), extraction method. At least a portion of the carbon dioxide is preferably used in a post treatment process for remineralization of said fluids.
  • the module for precipitating at least partially calcium-hydroxide is configured to increase the pH to a level of at least 10, more preferably wherein increasing the pH to a level of at least 10 is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and calcium hydroxide (Ca(OH)2).
  • At least a portion of the calcium hydroxide formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process; (c) any combination thereof.
  • the system according to the second aspect of the invention may further comprise a regeneration module for regeneration of sodium hydroxide (NaOH).
  • Said regeneration module for sodium hydroxide may comprise feeding sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM. Feeding said sodium chloride, NaCI, through said at least one EDBM may additionally result in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas. Preferably, this step also results in generating sodium hydroxide (NaOH), hydrochloric acid (HCI).
  • the at least one reactor containing calcium hydroxide (CafOH ) of the system according to the second aspect of the invention may also precipitate magnesium hydroxide from at least a portion of the fluids passed therethrough.
  • the system may further comprise a regeneration module for regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
  • the regeneration module may comprise: a. at least one module for dissolving at least partially said magnesium hydroxide; and, b. at least one module for precipitating at least partially magnesium-hydroxide.
  • Said module for dissolving said magnesium hydroxide may include adding at least one acid, preferably wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof. More preferably, said addition of hydrochloric acid (HCI), results in the generation of magnesium chloride (MgCL).
  • HCI hydrochloric acid
  • H2SO4 sulfuric acid
  • MgCL magnesium chloride
  • said module for precipitating magnesium-hydroxide is configured to increase the pH to a level of at least 8, more preferably increasing the pH to a level of at least 10, optionally by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and magnesium hydroxide (MgfOH ).
  • NaOH sodium hydroxide
  • CaCI sodium chloride
  • MgfOH magnesium hydroxide
  • At least a portion of the magnesium hydroxide formed by the system is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process; (c) any combination thereof.
  • the system preferably includes a module for regeneration of sodium hydroxide (NaOH).
  • Said regeneration module for regenerating sodium hydroxide may comprise at least one electrodialysis bipolar membranes, EDBM, wherein said sodium chloride (NaCI) is fed through the membrane.
  • EDBM electrodialysis bipolar membranes
  • feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
  • feeding said sodium chloride (NaCI) through said at least one EDBM may result in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
  • the system may also be configured to add at least a portion of the regenerated magnesium- based chemical to the permeate to produce product water.
  • system may further comprise a nanofiltration module to generate a solution comprising at least one of sodium chloride (NaCI), sodium sulfate (NajSC ), and any combination thereof; from at least one selected from a group consisting of seawater, brine and any combination thereof.
  • NaCI sodium chloride
  • NajSC sodium sulfate
  • the system includes at least one conduit for feeding said solution comprising at least one of sodium chloride (NaCI), sodium sulphate (NajSC ) and any combination thereof, through said at least one EDBM to generate at least one of sodium hydroxide (NaOH), hydrochloric acid (HCI), and sulfuric acid (H2SO4) and any combination thereof.
  • NaCI sodium chloride
  • NajSC sodium sulphate
  • H2SO4 sulfuric acid
  • Figures 1A-1K is a schematic diagram illustrating different stages of a sustainable desalination plant and process according to an embodiment of the present invention.
  • the present invention is concerned with improving a sea water desalination process and plant by increasing their sustainability. This is achieved by the self-generation of most of the chemicals used in the desalination process/plant, thus reducing the need to deliver chemicals to the plant.
  • the invention allows the production of the required chemicals onsite without the need to purchase and deliver the chemicals to the plant.
  • the chemicals required for remineralization may vary from plant to plant and can be (1) calcium carbonate and carbon dioxide or (2) calcium hydroxide and carbon dioxide. In addition, magnesium hydroxide may also be required.
  • the ability to provide onsite production of these chemicals provides (1) high availability of the plant; and (2) an environmentally friendly approach.
  • input sea water are reacted with lime (calcium hydroxide, CafOH ) prior to its passage through the reverse osmosis passes to precipitate calcium carbonate.
  • lime calcium hydroxide, CafOH
  • concentrated fluids e.g., brine, wastewater etc.
  • lime calcium hydroxide, Ca OH
  • the calcium carbonate is then subsequently regenerated (by e.g., calcination/hydrolysis, as will be detailed hereinbelow, of the calcium carbonate) for reuse in the process/plant.
  • This provides for a series of benefits in the overall cost efficiency and sustainability of the process/plant as detailed below.
  • Figures 1A to IE illustrate the different stages in the desalination process and plant of the present invention.
  • the process can be divided into four stages/modules (figures 1A-1D) (i) a seawater/brine softening stage; (ii) a chemical preparation for remineralization stage; (iii) a remineralization stage; and (iv) an acid and base preparation stage, with an optional additional fifth stage/module (Figure IE).
  • Figure 1A illustrates the first seawater/brine softening stage comprising precipitation of calcium carbonate alone or together with magnesium hydroxide from the fluids (seawater/brine/wastewater etc.).
  • the precipitation is done in a precipitation unit, for example a fluidized bed reactor.
  • calcium hydroxide (Ca OH ) is added to the precipitation unit. Addition of calcium hydroxide increases the pH, converts part of bicarbonates in the water to carbonates and increases the saturation potential of calcium carbonate and magnesium hydroxide.
  • the fluids (seawater/brine/wastewater etc.)are passed through the precipitation unit (such as a fluidized bed reactor) prior to filtration. Optionally, the filtered water may then be delivered to a clearwell.
  • Calcium hydroxide is introduced into the precipitation unit raising the pH of the water to at least 8.3 or higher and precipitating out calcium carbonate (and, optionally, magnesium hydroxide), according to the following equation:
  • the desalination process and plant of the present invention may not require any calcium carbonate contactors.
  • the calcium carbonate pellets produced as a by-product from the precipitation unit are delivered to a regenerator (hydrolysis or calcinatory, see also details in Fig. II) for the production of calcium-based chemicals, such as calcium hydroxide, calcium oxide, and carbon dioxide in the second chemical preparation stage of the process (see Figure IB).
  • the calcium-based chemicals will be reused in the precipitation unit (or in the post treatment process) and the carbon dioxide may be used in the post treatment process (to produce drinking water), as detailed in relation to Figure 1C below.
  • the second stage/module of the process/plant as shown schematically in Figure IB comprises a remineralization chemicals preparation stage to prepare chemicals required for the remineralization stage.
  • a remineralization chemicals preparation stage to prepare chemicals required for the remineralization stage.
  • calcium carbonate (with or without magnesium hydroxide) produced in stage one is dissolved by adding hydrochloric acid in a calcium carbonate (and optionally magnesium hydroxide) dissolution unit.
  • hydrochloric acid causes production of calcium chloride / magnesium chloride solution and carbon dioxide gas: CaCO3 + 2HCI -> CaCI2 + CO2 + H2O; and/or
  • carbon dioxide is extracted from the obtained solution in the carbon dioxide extraction unit, for example by using pervaporation membranes.
  • the magnesium hydroxide is precipitated by addition of sodium hydroxide in the magnesium hydroxide precipitation unit.
  • Magnesium hydroxide precipitation is done at pH levels above 9.0.
  • the calcium hydroxide is precipitated by addition of sodium hydroxide in the calcium hydroxide precipitation unit (Calcium hydroxide precipitation is done at pH levels above 11.0), see Fig. IB.
  • Excess sodium chloride solution produced in this stage of the process can be used for sodium hydroxide and hydrochloric acid preparation in the optional fifth stage (see below, Fig. IE).
  • the intake water may pass through the precipitation reactor to increase the pH of the water and form calcium carbonate. According to one embodiment, only a portion is passed through the reactor.
  • the third remineralization stage of the process/plant is illustrated schematically in Figure 1C.
  • Calcium hydroxide, carbon dioxide and potentially magnesium hydroxide produced during the second stage is added to the reverse osmosis product water in a remineralization unit to produce drinking water that meets regulation requirements.
  • the fourth acid and base preparation stage prepares the hydrochloric acid and sodium hydroxide for use in the second stage.
  • Various methods may be used to produce these chemicals on site from sea water or brine, with one example using nanofiltration illustrated in Figure ID. Their preparation may be done using electrodialysis with bipolar membranes (EDBM). Seawater or brine should be treated to meet EDBM feed water quality requirement.
  • EDBM bipolar membranes
  • Seawater or brine should be treated to meet EDBM feed water quality requirement.
  • seawater and/or brine concentrate are first treated with NF membrane to produce a NF brine and NF product (containing NaCI).
  • the NF product (containing NaCI) is then transferred to the EDBM to produce hydrochloric acid and sodium hydroxide.
  • FIG. IE An additional, optional fifth acid and base preparation stage is illustrated schematically in Figure IE.
  • This stage also provides for the onsite preparation of hydrochloric acid and sodium hydroxide (NaOH) required in the second stage. Any excess sodium chloride solution remaining from the second part can be utilized for hydrochloric acid and sodium hydroxide preparation.
  • the solution will contain calcium residuals which must be removed, for example in a calcium removal/polishing unit. Carbon dioxide may be added to precipitate calcium carbonate, providing a pure sodium chloride solution. This is then fed through bipolar membranes (EDBM) to split the solution into the acid (hydrochloric acid) and the base (sodium hydroxide).
  • EDBM bipolar membranes
  • the present invention increases the self-sustainability of the process/plant by the on- situ production of calcium-based chemicals and carbon dioxide from the calcium carbonate precipitated which can be used for the post-treatment of the permeate to form product water, as well as being fed back to the reactor.
  • the process enables a much lower chemical consumption overall and allows for the use of smaller reactors.
  • the materials for providing these remineralization products can also be formed on site.
  • the process is also environmentally friendly because it reduces the amount of carbonates in the seawater as compared with standard desalination processes. This enables an increase in carbon capture by the sea, reducing the carbon footprint of the plant. More specifically, the desalination process of the present invention, by enabling the precipitation as disclosed above, removes carbon dioxide from seawater (and hence reduces the amount thereof) thereby facilitating carbon dioxide capture from the atmosphere.
  • the present invention provides a number of overall benefits, including energy saving, cost savings, self-manufacture of the required chemicals resulting in a chemical cost saving, additional profit from selling excess chemicals and carbon capture credits with a significant reduction in total operating costs.
  • the precipitation unit may also precipitate magnesium hydroxide (Mg(OH)z) from the sea water intake. This also enhances the sustainability of the process/plant because this chemical may also be required to provide satisfactory drinking water from permeate water, in addition to calcium hydroxide.
  • the magnesium hydroxide may be delivered to the permeate water to provide drinking water.
  • the magnesium hydroxide may be regenerated to form a magnesium-based chemical, such as magnesium oxide or magnesium hydroxide, which may be added to the permeate water, with any excess being sold for additional income.
  • Fig IF illustrating similarly to Fig. ID acid and base preparation utilizing EDBM.
  • sea water or brine are fed to nanofiltration membrane, NF membrane, to produce a NF brine and NF product.
  • the NF product is then transferred to the EDBM to produce hydrochloric acid and sodium hydroxide.
  • the Sodium Carbonate can be used in a dedicated reactor (e.g., fluidized bed reactor) to precipitate Magnesium Carbonate, MgC03 (see Fig. 1G, where the Magnesium Carbonate precipitation unit is essentially a fluidized bed reactor).
  • a dedicated reactor e.g., fluidized bed reactor
  • MgC03 The Magnesium Carbonate, MgC03, can be then introduced into a calcination unit to produce MgO:
  • the MgO can be added in the post treatment to the produced water (drinking water); or, it can be sold externally to any 3 rd party.
  • Fig. II illustrates the regeneration process of the calcium- based chemicals.
  • calcium carbonate, CaCO3 is introduced into a calciner to produce CO2 and CaO (or CaOH):
  • Fig. 1J illustrates the uses of the produced MgCO3, CO2 and the CaCO3 in the remineralization of the product water (post treatment).
  • the water coming out of the RO membrane is introduced with MgCO3 and CaCO3.
  • the water is introduced with CO2.
  • Fig. IK illustrates another embodiment of the present invention, where use of the acid generated by the EDBM is provided.
  • the hydrochloric acid produced is used to produce CO2 by dissolving MgCO3:
  • the CO2 can, as disclosed above, be used in the post treatment to produce the product water.
  • isotopic variants of compounds disclosed herein are intended to be encompassed by the disclosure.
  • any one or more hydrogens in a molecule disclosed can be replaced with deuterium or tritium.
  • Isotopic variants of a molecule are generally useful as standards in assays for the molecule and in chemical and biological research related to the molecule or its use. Methods for making such isotopic variants are known in the art. Specific names of compounds are intended to be exemplary, as it is known that one of ordinary skill in the art can name the same compounds differently.
  • ranges specifically include the values provided as endpoint values of the range.
  • ranges specifically include all the integer values of the range. For example, a range of 1 to 100 specifically includes the end point values of 1 and 100. It will be understood that any subranges or individual values in a range or subrange that are included in the description herein can be excluded from the claims herein.
  • the term "about” refers to any value being lower or greater than 20% of the defined measure.

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Abstract

A self-sustainable process and system for treating water wherein at least a portion of the water is fed through a reactor for the removal of carbonates-based chemical by precipitation and at least some of the calcium carbonate precipitant is regenerated to a calcium-based chemical and carbon dioxide which is at least partially utilized to remineralize said fluids in a post-treatment process.

Description

Sustainable Desalination Plant and Sustainable Method for the Desalination of Water
Field of the Invention
The present invention relates generally to a more environmentally sustainable production of desalinated water and to a sustainable desalination plant.
Background of the Invention
Desalination is a process that removes mineral components from sea water to provide water that is suitable for human consumption or irrigation. The by-product of the desalination process is brine, a super concentrated solution. A conventional seawater desalination plant delivers sea water, via an intake channel, through various pre-treatment sites such as filters before being pumped under pressure through multiple reverse osmosis passes to form desalinated product water and concentrated sea water or brine. During this process, other minerals in addition to salt are removed from the water which must be re-introduced to provide an acceptable product water and therefore the water is also subjected to posttreatments, such as pH adjustment and the addition of minerals such as magnesium before being held in a holding tank for later consumption. The brine may be discharged back into the sea via a discharge channel or subjected to a further desalination process to create additional product water.
Drinking water that leaves the desalination plant must have a certain concentration of minerals. Generally, the required minerals are purchased, delivered to the plant, and added to the reverse osmosis product in the final remineralization treatment stage of the desalination plant. The purchase and delivery of the chemicals make the operation problematic especially in places where those chemicals are unavailable. In addition, delivery / transportation of chemicals affects the environment, increasing the emission of carbon dioxide to the atmosphere. It is desirable to be able to produce the required chemicals onsite as this would significantly improve the sustainability of the desalination plant. It is an object of the present invention to provide an improved desalination process and system that aims to address this issue.
Summary of the Invention
According to a first aspect of the present invention there is provided a method of treating fluids, the process comprising: feeding at least a portion of said fluids through at least one reactor for the removal of carbonates-based chemicals by precipitation; regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and utilizing at least a portion of at least one selected from a group consisting of said calcium based chemical and carbon dioxide and any combination thereof, to remineralize said fluids; thereby treating the same.
The method may treat fluids selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
The reactor may contain calcium hydroxide (CafOH ) for the precipitation of calcium-based chemicals. Preferably, calcium hydroxide (CafOH ) is added to the at least one reactor to precipitate at least one carbonates-based chemical, more preferably wherein the at least one carbonates-based chemical is calcium carbonate (CaCOs), according to the following equation: Ca(OH)2 + CafHCOsh --> ZCaCOs + 2H2O.
Preferably, feeding at least a portion of said fluids through at least one reactor containing calcium hydroxide (Ca(OH)2) increases the pH of said fluids to at least pH 8.3.
In a preferred embodiment, the fluids comprise seawater and the method further comprises the step of desalinating said seawater. The method may include the additional step of delivering said seawater to at least one pass comprising at least one reverse osmosis membrane to produce permeate water and brine. Preferably, the regeneration step produces a calcium-based chemical selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof. The regeneration step may comprise the steps of: a. at least partially dissolving said calcium carbonate; and, b. at least partially precipitating calcium-hydroxide.
The said step of dissolving said calcium-based chemical is preferably performed by adding at least one acid. Said acid may be selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof.
In a preferred embodiment, the acid is hydrochloric acid (HCI) and its addition results in the generation of calcium chloride (CaCI) and carbon dioxide gas, (CO2).
Said carbon dioxide gas, (CO2), is preferably generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas, CO2, extraction method.
Preferably, at least a portion of the carbon dioxide is used in a post treatment process for remineralization of said fluids.
The step of at least partially precipitating calcium-hydroxide is preferably performed by increasing the pH to a level of at least 10, for example by the addition of sodium hydroxide (NaOH), to result in sodium chloride (NaCI) and calcium hydroxide (Ca(OH)2). The method may further comprise the additional step of regenerating sodium hydroxide (NaOH). Said step of regeneration of sodium hydroxide may be performed by feeding said sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM, preferably wherein said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas. The step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI). Preferably, at least a portion of the calcium hydroxide formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process; (c) any combination thereof.
The method of treating fluids according to the first aspect of the invention may also precipitate magnesium hydroxide during the step of feeding at least a portion of said fluids through at least one reactor containing calcium hydroxide (CafOH ). The method may further comprise the step of regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
The step of regenerating at least some of the magnesium hydroxide precipitant may comprise steps of: a. at least partially dissolving said magnesium hydroxide; and, b. at least partially precipitating magnesium-hydroxide.
Preferably, said step of dissolving said magnesium hydroxide is performed by adding at least one acid, more preferably wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof. It is preferable for the addition of hydrochloric acid (HCI), to result in the generation of magnesium chloride (MgCk).
In one embodiment, said step of at least partially precipitating magnesium-hydroxide is performed by increasing the pH to a level of at least 8, more preferably at least 10. Preferably the increase in pH is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and magnesium hydroxide (MgOHz). The method may further comprise the step of regeneration of sodium hydroxide (NaOH). Said step of regeneration of sodium hydroxide may be performed by feeding said sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM. Said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas. Preferably, said step of feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
It is preferable for at least a portion of the magnesium hydroxide formed by regeneration to be at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process; (c) any combination thereof.
The method may further comprise adding at least a portion of the regenerated magnesium- based chemical to the permeate to produce product water.
Preferably, the step of feeding at least a portion of water through the at least one reactor containing calcium hydroxide Ca(OH)2 according to the method of the first aspect of the invention also precipitates magnesium hydroxide; and the process further comprises the steps of (i) regenerating at least some of the calcium carbonate and magnesium hydroxide precipitants to produce a calcium- based chemical, a magnesium-based chemical and carbon dioxide; and, (ii) mixing at least some of the regenerated chemicals and carbon dioxide with the permeate product water to produce drinking water.
The method according to the first aspect of the present invention preferably excludes a calcium carbonate contactor in the post-treatment of the permeate water.
The method may further comprise the optional step of utilizing nanofiltration to generate a solution comprising at sodium chloride (NaCI) and sodium sulfate (NazSC ), and any combination thereof; from at least one selected from a group consisting of seawater, brine and any combination thereof. Preferably, the method may further comprise a step of feeding said solution comprising at least one of sodium chloride (NaCI), and sodium sulphate (Na2SO4) and any combination thereof, through at least one electrodialysis bipolar membranes EDBM to regenerate sodium hydroxide (NaOH), hydrochloric acid (HCI), and sulfuric acid (H2SO4) and any combination thereof. A second aspect of the present invention provide a self-sustainable system for treating fluids, the system comprising: at least one conduit for delivering at least a portion of fluids to at least one reactor for the removal of at least one carbonates-based chemical by precipitation; at least one regeneration module for regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and at least one remineralization module utilizing at least a portion of at least one selected from a group consisting of said calcium based-chemical and carbon dioxide and any combination thereof, to remineralize said fluids.
Preferably, the fluids are selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
Preferably, the at least one reactor contains calcium hydroxide (CafOH ) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3), more preferably wherein the reactor contains calcium hydroxide (Ca(OH)2) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3), according to the following equation: Ca(OH)2 + Ca(HCO3)2 --> 2CaCO3 + 2H2O.
Preferably, the system further comprises at least one conduit for introducing calcium hydroxide (Ca(OH)2) into the at least one reactor.
In a preferred embodiment, the fluids are seawater; further wherein said system additionally comprises at least one reverse osmosis pass comprising at least one reverse osmosis membrane.
Preferably, the regeneration module of the system produces a calcium-based chemical selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof. Said regeneration module of the calcium carbonate to said calcium-based chemical may comprise: a. at least one module for dissolving at least partially said calcium carbonate; and, b. at least one module for precipitating at least partially calcium-hydroxide.
Said module for dissolving said calcium-based chemical may comprise at least one conduit for introducing acid into the same, preferably wherein the acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4),and any combination thereof.
More preferably, the conduit introduces hydrochloric acid (HCI), to result in the generation of calcium chloride (CaCL), and carbon dioxide gas (CO2). The carbon dioxide gas (CO2), may be generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas (CO2), extraction method. At least a portion of the carbon dioxide is preferably used in a post treatment process for remineralization of said fluids.
In a preferred embodiment, the module for precipitating at least partially calcium-hydroxide is configured to increase the pH to a level of at least 10, more preferably wherein increasing the pH to a level of at least 10 is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and calcium hydroxide (Ca(OH)2).
Preferably, at least a portion of the calcium hydroxide formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process; (c) any combination thereof.
The system according to the second aspect of the invention may further comprise a regeneration module for regeneration of sodium hydroxide (NaOH). Said regeneration module for sodium hydroxide may comprise feeding sodium chloride (NaCI), through at least one electrodialysis bipolar membranes, EDBM. Feeding said sodium chloride, NaCI, through said at least one EDBM may additionally result in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas. Preferably, this step also results in generating sodium hydroxide (NaOH), hydrochloric acid (HCI). The at least one reactor containing calcium hydroxide (CafOH ) of the system according to the second aspect of the invention may also precipitate magnesium hydroxide from at least a portion of the fluids passed therethrough. In this embodiment, the system may further comprise a regeneration module for regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical. The regeneration module may comprise: a. at least one module for dissolving at least partially said magnesium hydroxide; and, b. at least one module for precipitating at least partially magnesium-hydroxide.
Said module for dissolving said magnesium hydroxide may include adding at least one acid, preferably wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof. More preferably, said addition of hydrochloric acid (HCI), results in the generation of magnesium chloride (MgCL).
Preferably, said module for precipitating magnesium-hydroxide is configured to increase the pH to a level of at least 8, more preferably increasing the pH to a level of at least 10, optionally by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI), and magnesium hydroxide (MgfOH ).
At least a portion of the magnesium hydroxide formed by the system is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process; (c) any combination thereof.
The system preferably includes a module for regeneration of sodium hydroxide (NaOH). Said regeneration module for regenerating sodium hydroxide may comprise at least one electrodialysis bipolar membranes, EDBM, wherein said sodium chloride (NaCI) is fed through the membrane. Preferably, feeding said sodium chloride (NaCI), through said at least one EDBM additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas. Additionally, feeding said sodium chloride (NaCI) through said at least one EDBM may result in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI). The system may also be configured to add at least a portion of the regenerated magnesium- based chemical to the permeate to produce product water.
Additionally, the system may further comprise a nanofiltration module to generate a solution comprising at least one of sodium chloride (NaCI), sodium sulfate (NajSC ), and any combination thereof; from at least one selected from a group consisting of seawater, brine and any combination thereof.
Preferably, the system includes at least one conduit for feeding said solution comprising at least one of sodium chloride (NaCI), sodium sulphate (NajSC ) and any combination thereof, through said at least one EDBM to generate at least one of sodium hydroxide (NaOH), hydrochloric acid (HCI), and sulfuric acid (H2SO4) and any combination thereof.
Brief Description of the Drawings
For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which:
Figures 1A-1K is a schematic diagram illustrating different stages of a sustainable desalination plant and process according to an embodiment of the present invention.
Detailed Description Of The Invention
The present invention is concerned with improving a sea water desalination process and plant by increasing their sustainability. This is achieved by the self-generation of most of the chemicals used in the desalination process/plant, thus reducing the need to deliver chemicals to the plant. The invention allows the production of the required chemicals onsite without the need to purchase and deliver the chemicals to the plant. The chemicals required for remineralization may vary from plant to plant and can be (1) calcium carbonate and carbon dioxide or (2) calcium hydroxide and carbon dioxide. In addition, magnesium hydroxide may also be required. The ability to provide onsite production of these chemicals provides (1) high availability of the plant; and (2) an environmentally friendly approach.
According to one embodiment of the present invention input sea water are reacted with lime (calcium hydroxide, CafOH ) prior to its passage through the reverse osmosis passes to precipitate calcium carbonate. Alternatively, concentrated fluids (e.g., brine, wastewater etc.) are reacted with lime (calcium hydroxide, Ca OH ) passes to precipitate calcium carbonate.
The calcium carbonate is then subsequently regenerated (by e.g., calcination/hydrolysis, as will be detailed hereinbelow, of the calcium carbonate) for reuse in the process/plant. This provides for a series of benefits in the overall cost efficiency and sustainability of the process/plant as detailed below.
Figures 1A to IE illustrate the different stages in the desalination process and plant of the present invention. The process can be divided into four stages/modules (figures 1A-1D) (i) a seawater/brine softening stage; (ii) a chemical preparation for remineralization stage; (iii) a remineralization stage; and (iv) an acid and base preparation stage, with an optional additional fifth stage/module (Figure IE).
Figure 1A illustrates the first seawater/brine softening stage comprising precipitation of calcium carbonate alone or together with magnesium hydroxide from the fluids (seawater/brine/wastewater etc.). The precipitation is done in a precipitation unit, for example a fluidized bed reactor.
To precipitate calcium carbonate alone or together with magnesium hydroxide, calcium hydroxide (Ca OH ) is added to the precipitation unit. Addition of calcium hydroxide increases the pH, converts part of bicarbonates in the water to carbonates and increases the saturation potential of calcium carbonate and magnesium hydroxide. The fluids (seawater/brine/wastewater etc.)are passed through the precipitation unit (such as a fluidized bed reactor) prior to filtration. Optionally, the filtered water may then be delivered to a clearwell. Calcium hydroxide is introduced into the precipitation unit raising the pH of the water to at least 8.3 or higher and precipitating out calcium carbonate (and, optionally, magnesium hydroxide), according to the following equation:
Figure imgf000013_0001
This stage leads to operating at a higher pH, converts part of the biocarbonates to carbonates and increases the saturation potential of calcium carbonate and magnesium hydroxide. In turn, this leads to better biofouling resistance, better boron rejection and enables post treatment reactors to be free from calcium carbonate reactors. Instead, the post treatment reactors are replaced with the simple addition of lime (calcium hydroxide) and carbon dioxide to form the final product.
Thus, the desalination process and plant of the present invention may not require any calcium carbonate contactors. Additionally, the calcium carbonate pellets produced as a by-product from the precipitation unit are delivered to a regenerator (hydrolysis or calcinatory, see also details in Fig. II) for the production of calcium-based chemicals, such as calcium hydroxide, calcium oxide, and carbon dioxide in the second chemical preparation stage of the process (see Figure IB). The calcium-based chemicals will be reused in the precipitation unit (or in the post treatment process) and the carbon dioxide may be used in the post treatment process (to produce drinking water), as detailed in relation to Figure 1C below.
The second stage/module of the process/plant as shown schematically in Figure IB comprises a remineralization chemicals preparation stage to prepare chemicals required for the remineralization stage. Firstly, calcium carbonate (with or without magnesium hydroxide) produced in stage one is dissolved by adding hydrochloric acid in a calcium carbonate (and optionally magnesium hydroxide) dissolution unit.
The addition of hydrochloric acid causes production of calcium chloride / magnesium chloride solution and carbon dioxide gas: CaCO3 + 2HCI -> CaCI2 + CO2 + H2O; and/or
Mg(0H)2 + 2HCI -> MgCI2 + 2H2O
According to one embodiment, carbon dioxide is extracted from the obtained solution in the carbon dioxide extraction unit, for example by using pervaporation membranes.
According to another embodiment, if magnesium exists in the solution, the magnesium hydroxide is precipitated by addition of sodium hydroxide in the magnesium hydroxide precipitation unit. Magnesium hydroxide precipitation is done at pH levels above 9.0. After magnesium hydroxide precipitation, the calcium hydroxide is precipitated by addition of sodium hydroxide in the calcium hydroxide precipitation unit (Calcium hydroxide precipitation is done at pH levels above 11.0), see Fig. IB.
Excess sodium chloride solution produced in this stage of the process can be used for sodium hydroxide and hydrochloric acid preparation in the optional fifth stage (see below, Fig. IE).
It is to be appreciated that some or all of the intake water may pass through the precipitation reactor to increase the pH of the water and form calcium carbonate. According to one embodiment, only a portion is passed through the reactor.
The third remineralization stage of the process/plant is illustrated schematically in Figure 1C. Calcium hydroxide, carbon dioxide and potentially magnesium hydroxide produced during the second stage is added to the reverse osmosis product water in a remineralization unit to produce drinking water that meets regulation requirements.
The fourth acid and base preparation stage prepares the hydrochloric acid and sodium hydroxide for use in the second stage. Various methods may be used to produce these chemicals on site from sea water or brine, with one example using nanofiltration illustrated in Figure ID. Their preparation may be done using electrodialysis with bipolar membranes (EDBM). Seawater or brine should be treated to meet EDBM feed water quality requirement. As illustrated in the figure seawater and/or brine concentrate are first treated with NF membrane to produce a NF brine and NF product (containing NaCI). The NF product (containing NaCI) is then transferred to the EDBM to produce hydrochloric acid and sodium hydroxide.
An additional, optional fifth acid and base preparation stage is illustrated schematically in Figure IE. This stage also provides for the onsite preparation of hydrochloric acid and sodium hydroxide (NaOH) required in the second stage. Any excess sodium chloride solution remaining from the second part can be utilized for hydrochloric acid and sodium hydroxide preparation. The solution will contain calcium residuals which must be removed, for example in a calcium removal/polishing unit. Carbon dioxide may be added to precipitate calcium carbonate, providing a pure sodium chloride solution. This is then fed through bipolar membranes (EDBM) to split the solution into the acid (hydrochloric acid) and the base (sodium hydroxide).
Thus, the present invention increases the self-sustainability of the process/plant by the on- situ production of calcium-based chemicals and carbon dioxide from the calcium carbonate precipitated which can be used for the post-treatment of the permeate to form product water, as well as being fed back to the reactor. The process enables a much lower chemical consumption overall and allows for the use of smaller reactors. The materials for providing these remineralization products can also be formed on site.
Furthermore, the process is also environmentally friendly because it reduces the amount of carbonates in the seawater as compared with standard desalination processes. This enables an increase in carbon capture by the sea, reducing the carbon footprint of the plant. More specifically, the desalination process of the present invention, by enabling the precipitation as disclosed above, removes carbon dioxide from seawater (and hence reduces the amount thereof) thereby facilitating carbon dioxide capture from the atmosphere.
Thus, the present invention provides a number of overall benefits, including energy saving, cost savings, self-manufacture of the required chemicals resulting in a chemical cost saving, additional profit from selling excess chemicals and carbon capture credits with a significant reduction in total operating costs. As noted above, the precipitation unit may also precipitate magnesium hydroxide (Mg(OH)z) from the sea water intake. This also enhances the sustainability of the process/plant because this chemical may also be required to provide satisfactory drinking water from permeate water, in addition to calcium hydroxide. Thus, the magnesium hydroxide may be delivered to the permeate water to provide drinking water. Again, the magnesium hydroxide may be regenerated to form a magnesium-based chemical, such as magnesium oxide or magnesium hydroxide, which may be added to the permeate water, with any excess being sold for additional income.
According to another embodiment of the present invention CO2 capture from the air to facilitate MgC03 precipitation.
Reference is n ow made to Fig IF, illustrating similarly to Fig. ID acid and base preparation utilizing EDBM. As discussed, sea water or brine, are fed to nanofiltration membrane, NF membrane, to produce a NF brine and NF product. The NF product is then transferred to the EDBM to produce hydrochloric acid and sodium hydroxide.
Next the sodium hydroxide, NaOH, is let to be exposed to air thereby to capture CO2 from the air to produce Na2CO3:
2NaOH + CO2 -> Na2CO3 + H2O.
The Sodium Carbonate can be used in a dedicated reactor (e.g., fluidized bed reactor) to precipitate Magnesium Carbonate, MgC03 (see Fig. 1G, where the Magnesium Carbonate precipitation unit is essentially a fluidized bed reactor).
The Magnesium Carbonate, MgC03, can be then introduced into a calcination unit to produce MgO:
MgC03 -> MgO + CO2 (see Fig. 1H).
Needless to say that the MgO can be added in the post treatment to the produced water (drinking water); or, it can be sold externally to any 3rd party. Reference is now made to Fig. II which illustrates the regeneration process of the calcium- based chemicals. As seen in the figure, as one example, calcium carbonate, CaCO3, is introduced into a calciner to produce CO2 and CaO (or CaOH):
CaCO3-> CaO + CO2.
Reference is now made to Fig. 1J, which illustrates the uses of the produced MgCO3, CO2 and the CaCO3 in the remineralization of the product water (post treatment). As illustrated, the water coming out of the RO membrane is introduced with MgCO3 and CaCO3. Next, to produce the product water (drinking water), the water is introduced with CO2.
Reference is now made to Fig. IK which illustrates another embodiment of the present invention, where use of the acid generated by the EDBM is provided.
As illustrated in Fig. IK, the hydrochloric acid produced is used to produce CO2 by dissolving MgCO3:
2HCI + MgCO3 -> MgCI2 + CO2.
The CO2 can, as disclosed above, be used in the post treatment to produce the product water.
It is to be appreciated that modifications to the aforementioned process and systems may be made without departing from the principles embodied in the examples described and illustrated herein.
All references cited throughout this application, for example patent documents including issued or granted patents or equivalents; patent application publications; and non-patent literature documents or other source material; are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in this application.
The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments, exemplary embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. The specific embodiments provided herein are examples of useful embodiments of the present invention and it will be apparent to one skilled in the art that the present invention may be carried out using a large number of variations of the devices, device components, and method steps set forth in the present description. As will be obvious to one of skill in the art, methods and devices useful for the present methods can include a large number of optional composition and processing elements and steps.
When a group of substituents is disclosed herein, it is understood that all individual members of that group and all subgroups, including any isomers, enantiomers, and diastereomers of the group members, are disclosed separately. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and sub-combinations possible of the group are intended to be individually included in the disclosure. When a compound is described herein such that a particular isomer, enantiomer or diastereomer of the compound is not specified, for example, in a formula or in a chemical name, that description is intended to include each isomer and enantiomer of the compound described individually or in any combination. Additionally, unless otherwise specified, all isotopic variants of compounds disclosed herein are intended to be encompassed by the disclosure. For example, it will be understood that any one or more hydrogens in a molecule disclosed can be replaced with deuterium or tritium. Isotopic variants of a molecule are generally useful as standards in assays for the molecule and in chemical and biological research related to the molecule or its use. Methods for making such isotopic variants are known in the art. Specific names of compounds are intended to be exemplary, as it is known that one of ordinary skill in the art can name the same compounds differently.
It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to "a cell" includes a plurality of such cells and equivalents thereof known to those skilled in the art, and so forth. As well, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. It is also to be noted that the terms "comprising", "including", and "having" can be used interchangeably. The expression "of any of claims XX- YY" (wherein XX and YY refer to claim numbers) is intended to provide a multiple dependent claim in the alternative form, and in some embodiments is interchangeable with the expression "as in any one of claims XX- YY."
Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.
Whenever a range is given in the specification, for example, a range of integers, a temperature range, a time range, a composition range, or concentration range, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. As used herein, ranges specifically include the values provided as endpoint values of the range. As used herein, ranges specifically include all the integer values of the range. For example, a range of 1 to 100 specifically includes the end point values of 1 and 100. It will be understood that any subranges or individual values in a range or subrange that are included in the description herein can be excluded from the claims herein. The term "about" refers to any value being lower or greater than 20% of the defined measure.
As used herein, "comprising" is synonymous and can be used interchangeably with "including," "containing," or "characterized by," and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. As used herein, "consisting of" excludes any element, step, or ingredient not specified in the claim element. As used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. In each instance herein any of the terms "comprising", "consisting essentially of" and "consisting of" can be replaced with either of the other two terms. The invention illustratively described herein suitably can be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein.
One of ordinary skill in the art will appreciate that starting materials, biological materials, reagents, synthetic methods, purification methods, analytical methods, assay methods, and biological methods other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such materials and methods are intended to be included in this invention. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed can be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

Claims

1. A method of treating fluids, the process comprising: feeding at least a portion of said fluids through at least one reactor for the removal of carbonates-based chemical by precipitation; regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and utilizing at least a portion of at least one selected from a group consisting of said calcium-based chemical and carbon dioxide and any combination thereof, to remineralize said fluids; thereby treating the same.
2. The method according to claim 1, wherein said fluids are selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
3. The method according to claim 1 or claim 2, wherein the reactor contains calcium hydroxide (Ca(OH)2) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3), according to the equation Ca(OH)2 + Ca(HCO3)2 --> 2CaCO3 + 2H2O.
4. The method according to any one of claims 1-3, further comprising introducing calcium hydroxide (Ca(OH)2) into the at least one reactor.
5. The method according to claim 3 or claim 4, wherein feeding at least a portion of said fluids through at least one reactor containing calcium hydroxide (Ca(OH)2) increases the pH of said fluids to at least pH 8.3.
6. The method according to any one of claims 1-5, wherein at least one of the following is held true (a) said fluids are provided from a filtration process; said filtration being selected from a group consisting of desalination of seawater, reverse osmosis, forward osmosis, pressure-retarded osmosis, ultrafiltration, microfiltration and nanofiltration any combination thereof; optionally wherein said reactor is positioned in at least one location selected from a group consisting of prior to said filtration, post said filtration and any combination thereof; (b) said fluids are seawater; further wherein said method additionally comprises a step of desalinating said seawater; and any combination thereof.
7. The method according to claim 6, further comprising a step of delivering said seawater to at least one pass comprising at least one reverse osmosis membrane to produce permeate water and brine.
8. The method according to claim 1, wherein the calcium-based chemical is selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof.
9. The method according to any one of claims 1 - 8, wherein regenerating the calcium carbonate to said calcium-based chemical comprises steps of: a. at least partially dissolving said calcium carbonate; and, b. at least partially precipitating calcium-hydroxide.
10. The method according to claim 9, wherein said step of dissolving said calcium-based chemical is performed by adding at least one acid.
11. The method according to claims 10, wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof.
12. The method according to claim 11, wherein the acid is hydrochloric acid (HCI) and results in the generation of calcium chloride (CaCL) and carbon dioxide gas (CO2).
13. The method according to claim 12, wherein said carbon dioxide gas (CO2), is generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas (CO2) extraction method.
14. The method according to any one of claims 12-13, wherein at least a portion of the carbon dioxide is used in a post treatment process for remineralization of said fluids.
15. The method according to claims 9-14, wherein said step of at least partially precipitating of calcium-hydroxide is performed by increasing the pH to a level of at least 10.
16. The method according to claim 15, wherein said increasing the pH to a level of at least 10 is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI) and calcium hydroxide (Ca(OH)2).
17. The method according to claim 16, additionally comprising a step of regenerating sodium hydroxide (NaOH).
18. The method according to claim 17, wherein said step of regenerating sodium hydroxide is performed by feeding said sodium chloride (NaCI) through at least one electrodialysis bipolar membranes (EDBM).
19. The method according to claim 18, wherein said step of feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
20. The method according to claim 19 or 20, wherein said step of feeding said sodium chloride (NaCI) through said at least one EDBM additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
21. The method according to any one of claims 1-20, wherein at least a portion of the calcium- based chemical formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process;
(c) any combination thereof.
22. The method according to any one of claims 1-21, wherein feeding at least a portion of fluids through the at least one reactor containing calcium hydroxide (CafOH ) also precipitates magnesium hydroxide.
23. The method according to claim 22, further comprising the step of regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
24. The method according to claim 17, where said NaOH is used to capture CO2 from the air to produce Na2CO3.
25. The method according to claim 24, where said Na2CO3 is adapted to precipitate Mg2CO3.
26. The method according to claim 25, where said Mg2CO3 is precipitated in a precipitation reactor being a fluidized bed reactor.
27. The method according to claim 26, additionally comprising step of calcinating said Mg2CO3 to produce at least one selected from a group consisting of MgO, Mg(OH)2, CO2 and any combination thereof.
28. The method according to claim 20-27, wherein said hydrochloric acid is used to dissolve MgCO3 to MgCI2 and CO2.
29. The method according to claim 23, wherein said step of regenerating at least some of the magnesium hydroxide precipitant comprises the steps of: a. at least partially dissolving said magnesium hydroxide; and, b. at least partially precipitating magnesium-hydroxide.
30. The method according to claims 29, wherein said step of dissolving said magnesium hydroxide is performed by adding at least one acid.
31. The method according to claims 30, wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4),and any combination thereof.
32. The method according to claim 41, wherein said acid is hydrochloric acid (HCI) resulting in the generation of magnesium chloride (MgCL).
33. The method according to claims 29-32, wherein said step of at least partially precipitating magnesium-hydroxide is performed by increasing the pH to a level of at least 8, preferably at least 10.
34. The method according to claim 33, wherein said increasing the pH level is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI) and magnesium hydroxide (MgOHj).
35. The method according to any one of claims 29-34, wherein at least a portion of the magnesium hydroxide formed is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process; (c) any combination thereof.
36. The method according to claim 34, further comprising a step of regenerating sodium hydroxide (NaOH).
37. The method according to claim 36, wherein said step of regenerating sodium hydroxide is performed by feeding said sodium chloride (NaCI) through at least one electrodialysis bipolar membranes (EDBM).
38. The method according to claims 37, wherein said step of feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
39. The method according to claims 37-38, wherein said step of feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
40. The method according to claims 23-39, further comprising adding at least a portion of the regenerated magnesium-based chemical to the permeate to produce product water.
41. The method according to claim 1, wherein the fluids comprise sea water, brine, effluent, wastewater or any combination thereof and feeding at least a portion of the fluids through the at least one reactor containing calcium hydroxide Ca(OH)2 also precipitates magnesium hydroxide; the process further comprising the steps of (i) regenerating at least some of the calcium carbonate and magnesium hydroxide precipitants to produce a calcium- based chemical, a magnesium-based chemical and carbon dioxide; and, (ii) mixing at least some of the regenerated chemicals and carbon dioxide with permeate product water to produce drinking water.
42. The method according to any one of claims 1-41, wherein the process excludes a calcium carbonate contactor in the remineralization of the fluids.
43. The method according to any one of claims 1-42, additionally comprising step of utilizing nanofiltration to generate a solution comprising at least one of sodium chloride (NaCI) and sodium sulfate (NajSC ), and any combination thereof; from at least one selected from a group consisting of seawater, brine and any combination thereof.
44. The method according to claim 43, further comprising feeding said solution comprising at least one of sodium chloride (NaCI) and sodium sulphate (NajSC ) and any combination thereof, through at least one electrodialysis bipolar membranes (EDBM) to generate at least one of sodium hydroxide (NaOH), hydrochloric acid (HCI), and Sulfuric acid (H2SO4), and any combination thereof.
45. A self-sustainable system for treating fluids, comprising: at least one conduit for delivering at least a portion of fluids to at least one reactor for the removal of carbonates-based chemical by precipitation; at least one regeneration module for regenerating at least some of the calcium carbonate precipitant to a calcium- based chemical and carbon dioxide; and at least one remineralization module utilizing at least a portion of at least one selected from a group consisting of said calcium-based chemical and carbon dioxide and any combination thereof, to remineralize said fluids.
46. The system according to claim 45, wherein said fluids are selected from a group consisting of seawater, brine, effluent, wastewater and any combination thereof.
47. The system according to claim 45 or 46, wherein the reactor contains calcium hydroxide (Ca(OH)2) therein to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3).
48. The system according to claim 47, wherein the reactor containing calcium hydroxide (Ca(OH)2) therein precipitates at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3), according to the following equation: Ca(OH)2 + Ca(HCO3)2 --> 2CaCO3 + 2H2O.
49. The system according to any one of claims 45-48, further comprising at least one conduit for introducing calcium hydroxide (Ca(OH)2) into the at least one reactor.
50. The system according to any one of claims 45-49, wherein at least one of the following is held true (a) said fluids are provided from a filtration process; said filtration being selected from a group consisting of desalination of seawater, reverse osmosis, forward osmosis, pressure-retarded osmosis, ultrafiltration, microfiltration and nanofiltration any combination thereof; optionally wherein said reactor is positioned in at least one location selected from a group consisting of prior to said filtration, post said filtration and any combination thereof; (b) said fluids are seawater; further wherein said system additionally comprises at least one reverse osmosis pass comprising at least one reverse osmosis membrane; and any combination thereof.
51. The system according to claims 45-50, wherein the calcium-based chemical is selected from a group consisting of calcium hydroxide, calcium oxide and any combination thereof.
52. The system according to any one of claims 45 - 51, wherein said regeneration module of the calcium carbonate to said calcium-based chemical comprises: a. at least one module for dissolving at least partially said calcium carbonate; and, b. at least one module for precipitating at least partially calcium-hydroxide.
53. The system according to claim 52, wherein said module for dissolving said calcium-based chemical comprises at least one conduit for introducing acid into the same.
54. The system according to claims 53, wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof.
55. The system according to claim 54, wherein said acid is hydrochloric acid (HCI) resulting in the generation of calcium chloride (CaCL) and carbon dioxide gas (CO2).
56. The system according to claim 55, wherein said carbon dioxide gas (CO2) is generated in at least one pervaporation membrane, degasification, super cavitation and/or any other carbon dioxide gas (CO2) extraction apparatus.
57. The system according to claim 55 or claim 56, wherein at least a portion of the carbon dioxide is used in a post treatment process for the remineralization of said fluids.
58. The system according to claims 52-57, wherein said module for precipitating at least partially calcium-hydroxide is configured to increase the pH to a level of at least 10.
59. The system according to claim 58, wherein said increasing the pH to a level of at least 10 is performed by adding sodium hydroxide (NaOH) to result in sodium chloride (NaCI) and calcium hydroxide (Ca(OH)2).
60. The system according to claim 59, further comprising at least one regeneration module for regenerating sodium hydroxide (NaOH).
61. The system according to claim 60, wherein said regeneration module for sodium hydroxide comprises at least one electrodialysis bipolar membranes (EDBM) through which sodium chloride (NaCI) is fed.
62. The system according to claim 61, wherein feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in electrolysing water to provide oxygen (02) gas and hydrogen (H2) gas.
63. The system according to claim 61 or claim 62, wherein feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in re-generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
64. The system according to any one of claims 45-63, wherein at least a portion of the calcium- based chemical formed by regeneration of the calcium carbonate is at least one selected from (a) recycled for use in the at least one reactor; (b) used in a post treatment process for remineralization; (c) any combination thereof.
65. The system according to any one of claims 45-64, wherein feeding at least a portion of fluids through the at least one reactor containing calcium hydroxide (Ca OH ) also precipitates magnesium hydroxide.
66. The system according to claim 65, further comprising at least one regeneration module for regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
67. The system according to claim 60, where said NaOH is used to capture CO2 from the air to produce Na2CO3.
68. The system according to claim 67, where said Na2CO3 is adapted to precipitate Mg2CO3.
69. The system according to claim 68, where said Mg2CO3 is precipitated in a precipitation reactor being a fluidized bed reactor.
70. The system according to claim 69, additionally comprising step of calcinating said Mg2CO3 to produce at least one selected from a group consisting of MgO, Mg(OH)2, CO2 and any combination thereof.
71. The system according to claim 63-70, wherein said hydrochloric acid is used to dissolve MgCO3 to MgCI2 and CO2.
72. The system according to claim 71, wherein said regeneration module comprises: a. at least one module for dissolving at least partially said magnesium hydroxide; and, b. at least one module for precipitating at least partially magnesium-hydroxide.
73. The system according to claim 72, wherein said module for dissolving said magnesium hydroxide is configured to receive at least one acid.
74. The system according to claim 73, wherein said acid is selected from a group consisting of hydrochloric acid (HCI), sulfuric acid (H2SO4), and any combination thereof.
75. The system according to claim 74, wherein said acid is hydrochloric acid (HCI) to generate magnesium chloride (MgCL).
76. The system according to claims 72-75, wherein said module for precipitating of magnesium-hydroxide is configured to increase the pH to a level of at least 8.
77. The system according to claim 76, wherein said increasing the pH to a level of at least 8 is performed by adding sodium hydroxide (NaOH) to result in generation of sodium chloride (NaCI) and magnesium hydroxide (MgfOH ).
78. The system according to claim 77, further comprising at least one module for regenerating sodium hydroxide (NaOH).
79. The system according to claim 78, wherein said module for the regeneration of sodium hydroxide includes at least one electrodialysis bipolar membranes (EDBM) for receiving said sodium chloride (NaCI).
80. The system according to claim 79, wherein said feeding said sodium chloride, (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in electrolysing water to provide oxygen (O2) gas and hydrogen (H2) gas.
81. The system according to claim 79 or claim 80, wherein said feeding said sodium chloride (NaCI) through said at least one electrodialysis bipolar membranes (EDBM) additionally results in generating sodium hydroxide (NaOH) and hydrochloric acid (HCI).
82. The system according to any one of claims 72-81, wherein at least a portion of the magnesium hydroxide formed is at least one selected from (a) recycled for use in the at least one reactor; (b) used in the post treatment process for remineralization; (c) any combination thereof.
83. The system according to any one of claims 45-82, further comprising at least one nanofiltration module to generate a solution comprising at least one of sodium chloride (NaCI) and sodium sulfate (Na2SO4), and any combination thereof; from at least one fluid selected from a group consisting of seawater, brine and any combination thereof.
84. The system according to claim 83, further comprising at least one conduit for feeding said solution comprising at least one of sodium chloride (NaCI) and sodium sulphate (Na2SO4) and any combination thereof, through said at least one electrodialysis bipolar membranes (EDBM) additionally results in generating at least one of sodium hydroxide (NaOH), hydrochloric acid (HCI), sulfuric acid (H2SO4) and any combination thereof.
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