US-20260125303-A1 - SUSTAINABLE DESALINATION PLANT AND SUSTAINABLE METHOD FOR THE DESALINATION OF WATER

Abstract

Some embodiments relate to a sea water desalination process and plant that reacts the input sea water with calcium hydroxide 2 prior to its passage through a reverse osmosis pass 8 to precipitate calcium carbonate and increase the alkalinity of the water prior to its desalination. The calcium carbonate is converted in a regenerator 10 to produce calcium hydroxide and carbon dioxide. This provides for a series of benefits in the overall cost efficiency and sustainability of the process/plant.

Inventors

• Alex DRAK
• Tomer EFRAT

Assignees

• IDE WATER TECHNOLOGIES LTD.

Dates

Publication Date

20260507

Application Date

20231004

Priority Date

20221005

Claims (20)

1. 1 . A process for the desalination of sea water, the process comprising: feeding at least a portion of intake sea water through at least one reactor for the removal of carbonates-based chemical; and filtrating said intake sea water.
2. 2 . The process according to claim 1 , wherein said step of filtrating comprising desalinating said intake sea water to produce permeate product water and brine.
3. 3 . The process according to claim 1 , wherein said step of filtrating comprising at least one process selected from a group consisting of reverse osmosis, forward osmosis, pressure-retarded osmosis, ultrafiltration, microfiltration and nanofiltration any combination thereof.
4. 4 . The process according to claim 1 , wherein the reactor containing therein or is introduced with at least one selected from a group consisting calcium hydroxide (Ca(OH) 2 ), NaOH and any combination thereof to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO 3 ).
5. 5 . (canceled)
6. 6 . (canceled)
7. 7 . The process according to claim 1 , wherein feeding at least a portion of intake sea water through at least one reactor containing calcium hydroxide (Ca(OH) 2 ) increases the pH of the intake water to at least pH 8.3.
8. 8 . (canceled)
9. 9 . The process according to claim 1 , further comprising the step of regenerating at least some of the calcium carbonate precipitant to a calcium-based chemical and carbon dioxide.
10. 10 . The process according to claim 9 , wherein the calcium-based chemical is selected from a group consisting of calcium hydroxide or calcium oxide and any combination thereof.
11. 11 . The process according to any Ge of claims 9 - 19 , wherein regenerating the calcium carbonate to the calcium-based chemical comprises a method selected from at least one of calcinating the precipitated calcium carbonate, hydrolysing the precipitated calcium carbonate and any combination thereof.
12. 12 . The process according to claim 11 , wherein regenerating the calcium carbonate comprises calcination comprising heating the calcium carbonate to a temperature of at least 500° C.
13. 13 . The process according to claim 11 , wherein regenerating the calcium carbonate comprises hydrolysing the calcium carbonate to produce at least one selected from the group consisting of calcium hydroxide, calcium oxide, carbon dioxide and any combination thereof.
14. 14 . (canceled)
15. 15 . The process according to claim 13 , wherein the calcium-based chemical is calcium oxide and the process further comprises mixing at least a portion of the calcium oxide with at least a portion of intake sea water to form calcium hydroxide.
16. 16 . The process according to claim 10 , wherein 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.
17. 17 . The process according to claim 1 , wherein additionally comprising at least one step selected from a group consisting of (a) feeding at least a portion of intake sea water through the at least one reactor containing calcium hydroxide (Ca(OH) 2 ) also precipitates magnesium hydroxide; (b) feeding at least a portion of intake sea water through the at least one second reactor adapted to precipitate magnesium-based chemical selected from a group consisting of magnesium hydroxide, magnesium oxide and any combination thereof; and any combination thereof.
18. 18 . The process according to claim 17 , further comprising the step of regenerating at least some of the magnesium hydroxide precipitant to a magnesium-based chemical.
19. 19 . The process according to claim 18 , further comprising adding at least a portion of the regenerated magnesium-based chemical to the permeate to produce product water.
20. 20 . The process according to claim 1 , wherein feeding at least a portion of intake sea water through the at least one reactor containing calcium hydroxide (Ca(OH) 2 ) 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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national phase filing under 35 C.F.R. § 371 of and claims priority to PCT Patent Application No. PCT/US2023/034443, filed on Oct. 4, 2023, which claims the priority benefit under 35 U.S.C. § 119 of Israeli Patent Application No. 297088, filed on Oct. 5, 2022, the contents of which are hereby incorporated in their entireties by reference. FIELD OF THE DISCLOSURE The presently disclosed subject matter relates generally to a more environmentally sustainable production of desalinated water and to a sustainable desalination plant. BACKGROUND 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 post-treatments, 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. Conventional desalination processes and plants may include a single pass (as shown in FIG. 1) or a double pass (see FIG. 2), depending upon the required product water quality. One desalination process and system operated by the Applicant, IDE Technologies, is the two-pass concept as shown in FIG. 2 where sea water is delivered through an intake channel through a filtration module to a clearwell from which it is passed through a first sea water reverse osmosis pass (SWRO) with the brine then passing through a brackish water reverse osmosis (BWRO) pass. The combined permeate from both passes is then treated to provide final product water quality. This process and system use chemicals which are both very costly and affect the sustainability level of the process/plant. In the current two-pass SWRO process as shown in FIG. 1 the main chemicals used for operation are sodium hydroxide (NaOH), sulphuric acid (H2SO4), calcium carbonate (CaCO3) and carbon dioxide (CO2). The sodium hydroxide and sulphuric acid are used for boron rejection in the BWRO pass while calcium carbonate and carbon dioxide are used for final product remineralization in the post treatment stage. The cost of these chemicals is significant. It is desirable to improve this process to substantially reduce the total cost of the chemicals. Moreover, it would be advantageous to provide a self-sustainable desalination process/plant, or at least one that is partially self-sustainable, to self-produce the required chemicals for its own operation. It is an object of the presently disclosed subject matter to provide an improved desalination process and system that aims to address this issue. SUMMARY OF THE DISCLOSURE It is one object of the presently disclosed subject matter to provide a process for the desalination of sea water, the process comprising: feeding at least a portion of intake sea water through at least one reactor for the removal of carbonates-based chemical; andfiltrating said intake sea water. It is another object of the presently disclosed subject matter to provide the process as defined above, wherein said step of filtrating comprising desalinating said intake sea water to produce permeate product water and brine. It is another object of the presently disclosed subject matter to provide the process as defined above, wherein said step of filtrating comprising at least one process selected from a group consisting of reverse osmosis, forward osmosis, pressure-retarded osmosis, ultrafiltration, microfiltration and nanofiltration any combination thereof. It is another object of the presently disclosed subject matter to provide the process as defined above, wherein the reactor containing therein or is introduced with at least one selected from a group consisting calcium hydroxide (Ca(OH)2), NaOH and any combination thereof to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3). It is another object of the presently disclosed subject matter to provide the process as defined above, wherein the reactor containing therein or is introduced with at least one selected from a group consisting calcium hydroxide (Ca(OH)2), NaOH and any combination thereof to precipitate at least one carbonates-based chemical selected from a group consisting of calcium carbonate (CaCO3), according to the following formula: Ca(OH)2+Ca