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EP-4739631-A1 - SUSTAINABLE DESALINATION PLANT AND SUSTAINABLE METHOD FOR THE DESALINATION OF WATER

EP4739631A1EP 4739631 A1EP4739631 A1EP 4739631A1EP-4739631-A1

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.

Inventors

  • DRAK, Alex
  • EFRAT, Tomer

Assignees

  • IDE WATER TECHNOLOGIES LTD.

Dates

Publication Date
20260513
Application Date
20240705

Claims (20)

  1. 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. 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. 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 (CaCO 3 ), according to the equation Ca(OH) 2 + Ca(HCO 3 ) 2 --> 2CaCO 3 + 2H 2 O.
  4. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 17. The method according to claim 16, additionally comprising a step of regenerating sodium hydroxide (NaOH).
  18. 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. 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. 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).

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),