GB2499992A

GB2499992A - Water mineralization

Info

Publication number: GB2499992A
Application number: GB1203780.0A
Authority: GB
Inventors: Boris Liberman; Yosef Pinhas; Miriam Faigon
Original assignee: IDE Technologies Ltd
Current assignee: IDE Technologies Ltd
Priority date: 2012-03-05
Filing date: 2012-03-05
Publication date: 2013-09-11
Anticipated expiration: 2032-03-05
Also published as: GB2499992B; GB201203780D0; WO2013132399A1; IL234408B

Abstract

Water mineralization is performed by acidifying water, introducing and mixing carbonates in powder form into the acidic water, generating carbon dioxide in the water and adding turbidity to it. The treated water is then delivered through a reactor 80A with granular carbonates, in which the carbon dioxide in the water dissolves additional carbonates. The reactor acts simultaneously to add further minerals as well as alkalinity to the water, and to remove the turbidity out of the water by dissolving residual powder and filtering non-dissolvable particles. Carbon dioxide is recycled 128 by removing carbon dioxide from water exiting the reactor and introducing the removed carbon dioxide into water entering the reactor. A water mineralization system is also claimed. Preferably, the powdered and/or granular carbonates comprise at least one of: dolomite and calcite. The granular dolomite may be partially burnt dolomite. Water exiting the reactor can be mixed with desalinated water. A pH regulating module 118 may be arranged to adjust a pH of the mixed water by adding a base thereto.

Description

WATER MINERALIZATION

BACKGROUND

1. TECHNICAL FIELD

[0001] The present invention relates to post treatment of desalinated water, and more particularly, to water mineralization.

2. DISCUSSION OF THE RELATED ART

[0002] Figures 1A and IB illustrate two prior art systems for water mineralization. The figures illustrate Calcium mineralization by adding CO2 to the water 90, delivering the water through an upflow limestone reactor 80 and regulating the pH and CO2 content of the water. Figure IB illustrates a prior art variation with a CO2 degasifier 131 that removes CO2 from the mineralized water and delivers the CO2 into the entering permeate water 90. A problem in the prior art is that Magnesium has a much lower solubility than Calcium and hence prior art systems are not effective in mineralizing water with Magnesium.

BRIEF SUMMARY

[0003] One aspect of the invention provides a water mineralization system comprising: (i) a carbonates powder unit comprising an acid injection unit arranged to acidify water, a powder silo arranged to introduce carbonates powder into the acidified water, and a mixer arranged to mix the water with powdered carbonates to turn the carbonates into dissolvable mineral compounds and CO2, wherein powder rests are left in the water as turbidity, and (ii) a granular carbonates unit in fluid communication with the carbonates powder unit, arranged to receive the water therefrom and pass the water through a reactor with granular carbonates to dissolve additional mineral compounds and carbonate alkalinity upon reaction of the granular carbonates with the CO2, wherein the reactor is arranged to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through the reactor, the granular carbonates unit further comprising a CO2 recycling unit arranged to remove CO2 from water exiting the reactor and introduce the removed CO2 into water entering the reactor.

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[0004] These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] For a better understanding of embodiments of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding elements or sections throughout.

[0006] In the accompanying drawings:

Figures 2, 3A and 3B are high level schematic block diagrams illustrating a post treatment Magnesium mineralization system according to some embodiments of the invention, and

Figure 4 is a schematic flowchart illustrating a method of adding Magnesium to desalinated water, according to some embodiments of the invention.

[0007] The drawings together with the following detailed description make apparent to those skilled in the art how the invention may be embodied in practice.

DETAILED DESCRIPTION

[0008] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

[0009] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following

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description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0010] Figures 2, 3A and 3B are high level schematic block diagrams illustrating a water mineralization system 100 according to some embodiments of the invention. Figure 2 illustrates schematically the configuration and processes in system 100 and Figures 3A and 3B illustrate schematically two embodiments of system 100. Water mineralization system 100 may be used for mineralizing desalinated water as part of their post treatment, and may be used to replace or enhance prior art systems as illustrated in Figures 1A and IB.

[0011] System 100 comprises a carbonates powder unit 120 and a granular carbonates unit 130 in fluid communication with carbonates powder unit 120. Carbonates powder unit 120 receives a part 93 of water 90 and delivers a treated part 93A to granular carbonates unit 130 for further treatment, as explained below.

[0012] Carbonates powder unit 120 comprises an acid injection unit 117 arranged to acidify part 93 of water 90 and a powder mixing unit 116 comprising a powder silo 110 arranged to introduce carbonates powder into the acidified water and a mixer 115 arranged to mix the water with the powdered carbonates into the acidic water to turn the powdered carbonates into dissolvable mineral compounds and CO2. For example, carbonates may comprise calcite or dolomite, and mixer 115 mixes the water to dissolve CaCC>3 or CaMg(CC>3)2 respectively into Ca and Mg compounds.

[0013] Acid injection unit 117 may inject sulfuric acid, with the reaction in carbonates powder unit 120 being CaMg(C03)2+2H2S04 —> CaS04+MgS04+2C02+2H20. Acid injection unit 117 may inject hydrochloric acid, with the reaction in carbonates powder unit 120 being CaMg(C03)2+4HCl —> CaCl2+MgCl2+2C02+2H20. Both reactions, and generally any acid used in acid injection unit 117, introduce CO2 into the water. This has the advantage of sparing an external addition of CO2, as carried out in the prior art. Alternatively, CO2 may be directly introduced into water 93 to both acidify the water (though to a higher pH) and dissolve CO2 in the water. Acid injection unit 117 may inject any acid equivalent to sulfuric or hydrochloric acid.

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[0014] Using powdered calcite or dolomite has the advantage to effectively dissolving Ca or Ca and Mg (respectively) into the water. In prior art reactors using granular calcite or dolomite the dissolution rate is very low (especially for Magnesium, which has a lower dissolution rate than that of Calcium), and hence much larger reactor and needed. Dolomite powder not only allows loading large amounts of Magnesium into the water in a short period, but is also more cost effective than using granular dolomite.

[0015] A disadvantage in mixing carbonates powder into the water is that carbonates powder rests are left in the water as turbidity, which is not tolerated in the product water. The turbidity is composed of carbonates powder rests as well as non-dissolvable powder rests, for example silica powder. This difficulty is solved in granular carbonates unit 130 as explained below.

[0016] Granular carbonates unit 130 is arranged to receive water 93A from carbonates powder unit 120 and additional water 94, and pass the water through a reactor 80A with granular carbonates to dissolve additional mineral compounds and carbonate alkalinity (e.g. Ca(HCC>3)2, Mg(HCC>3)2) upon reaction of the granular carbonates with the CO2.

[0017] Reactor 80A may comprise one or more reaction chambers (see Figure 3A and 3B) and may configured to pass water through in an upflow or a downflow direction. Reactor 80A is further arranged to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through reactor 80 A, in an upflow or a downflow configuration.

[0018] Hence, the CO2 generated in the water by the reactions in carbonates powder unit 120 is used to dissolve the granular carbonates in granular carbonates unit 130, and granular carbonates unit 130 is used to remove the turbidity that was an unwanted result of powder mixing unit 116.

[0019] In case of the granular carbonates being dolomite, granular carbonates unit 130 reacts CaMg(CC>3)2 with the CO2 to dissolve Ca(HCC>3)2 and Mg(HCC>3)2 in the water and to remove the turbidity with reactor 80A acting as a filter. Granular carbonates may comprise granular calcite (CaCOs) as in prior art reactor 80, with the additional function of filtering non-dissolvable powder residues.

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[0020] Granular carbonates may also comprise granular partially burnt dolomite (MgOCaCOs) which dissolves to Mg at a higher pH than dolomite does (ca. pH=6.5 instead of pH=5.5), requiring less energy for subsequent CO2 removal (see below).

[0021] Granular carbonates unit 130 may further comprise a CO2 recycling unit 128 arranged to remove CO2 from water exiting reactor 80A and introduce the removed CO2 into water entering reactor 80A. CO2 recycling unit 128 regulates CO2 level of the water and its acidity, and recycles C02 produced in carbonates powder unit 120. CO2 recycling unit 128 may comprise a vacuum degasifier 131 arranged to remove residual CO2 from mineralized water 94A. CO2 from degasifier 131 may be pumped by pump 124 and added to the water delivered to reactor 80A (Figure 3B).

[0022] Mineralization system 100 further comprises a plurality of valves (e.g. 121, 122 and 123), arranged to conduct water through system 100. For example, as illustrated in Figures 2, 3A and 3B, valve 121 is arranged to separate a first part 92 of water 90 from a bulk 91 of water. Valve 122 separates a second part 93 of first part 92 and delivers second part 93 to carbonates powder unit 120. Water 93 mixed with the powder is then mixed via valve 123 with a rest 94 of first part 92 to enter granular carbonates unit 130. Water 94A emerging from granular carbonates unit 130 is optionally degasified and then mixed with bulk 91 to yield treated water 90A. The relative amounts of water as first and second parts 92 and 93 respectively are determined to maximize dissolution of powder with a minimal amount of water, in respect to the conditions of the water and characteristics of the carbonates with which it reacts.

[0023] Granular carbonates unit 130 may further comprise a pH regulation unit 128 that adjusts the pH level of the water. Unit 128 may comprise a base adding module 118 arranged to adjust a pH of the mineralized water 91 by adding a base (e.g. NaOH) (Figure 3A). pH regulation unit 128 regulated the pH level of the treated water after it is mixed with bulk 91 of water to control the pH of water 90A produced by system 100.

[0024] Carbonates powder in carbonates powder unit 120 may have a particle size between 5-75|a, e.g. around 25|_i. Granular carbonates in granular carbonates unit 130 may have a particle size of 2-5 mm. Exact characteristic of the carbonates powder and granular carbonates may vary according to the exact composition of the material.

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[0025] Figure 4 is a schematic flowchart illustrating a method 200, according to some embodiments of the invention.

[0026] Method 200 comprises improving the dissolution of carbonate minerals in water (stage 215) by acidifying the water (stage 220), reducing the particle size of carbonates introduced into the water, e.g. to powder (stage 230) and removing and dissolving residual powder particles from the water to remove the turbidity (stage 260). Mixing carbonates powder is a fast process which quickly dissolves minerals into the water but results in turbidity of undissolved and non-dissolvable rests. Removing turbidity is carried out in a reactor with granular carbonates in a slow process, which utilizes CO2 produced in the fast process to add carbonate alkalinity to the water (stage 252).

[0027] For example, method 200 may comprise adding Magnesium to desalinated water (stage 210) by mixing dolomite powder into the water (stage 235) as well as dissolving granular dolomite (stage 250). Reducing dolomite particle size (stage 230) increases the dissolution rate of the minerals in the water, which is particularly important for sparingly soluble Magnesium. The mineralized water is then introduced into the whole bulk of desalinated water. Method 200 also comprises introducing and mixing powdered carbonates into the acidic water to turn the carbonates into dissolvable minerals CaMg(C03>2 into dissolvable Ca and Mg compounds and CO2 (stage 235), possibly leaving dolomite powder rests in the water as turbidity, and contacting the water in at least one upflow reactor with granular dolomite (stage 240) to react CaMg(CC>3)2 with the CO2 to dissolve Ca(HCC>3)2 and Mg(HCC>3)2 in the water (stage 250) and to remove the turbidity (stage 260) by the reactor acting as an upflow or downflow filter.

[0028] Other examples include adding calcite in powder form to the water to enhance Ca compounds dissolution in the water, and using granular partially burnt dolomite (MgOCaCOs) as granular carbonates to elevate a necessary pH level for carbonates dissolution in the sloe process.

[0029] Acidifying the water (stage 220) may be carried out by adding sulfuric acid or hydrochloric acid into the water (stage 223) or by introducing CO2 into the water (stage 226).

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[0030] Method 200 may further comprise adjusting a pH level of the mineralized water (stage 270), e.g. by adding a base to the water (stage 272) and by removing residual CO2 from the water (stage 255). Method 200 may further comprise recycling the CO2 by degasifying CO2 from water exiting the reactor (stage 255).

[0031] In the above description, an embodiment is an example or implementation of the invention. The various appearances of "one embodiment", "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

[0032] Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[0033] Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

[0034] The invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0035] Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.

[0036] While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.

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Claims

CLAIMS What is claimed is:

1. A water mineralization system comprising:

a carbonates powder unit comprising:

an acid injection unit arranged to acidify water,

a powder silo arranged to introduce carbonates powder into the acidified water, and a mixer arranged to mix the water with powdered carbonates to turn the carbonates into dissolvable mineral compounds and CO2, wherein powder rests are left in the water as turbidity, and a granular carbonates unit in fluid communication with the carbonates powder unit, arranged to receive the water therefrom and pass the water through a reactor with granular carbonates to dissolve additional mineral compounds and carbonate alkalinity upon reaction of the granular carbonates with the CO2, wherein the reactor is arranged to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through the reactor, the granular carbonates unit further comprising a CO2 recycling unit arranged to remove CO2 from water exiting the reactor and introduce the removed CO2 into water entering the reactor.

2. The mineralization system of claim 1, wherein the powdered carbonates comprise at least one of: powdered dolomite (CaMg(CC>3)2) and powdered calcite (CaCOs).

3. The mineralization system of claim 1, wherein the granular carbonates comprise at least one of: granular dolomite (CaMg(CC>3)2), granular partially burnt dolomite (MgOCaCOs) and granular calcite (CaCOs).

4. The mineralization system of claim 1, wherein the granular carbonates comprise at least one of: granular dolomite (CaMg(CC>3)2), and granular calcite (CaCOs).

5. The mineralization system of claim 1, wherein the granular carbonates comprises granular partially burnt dolomite (MgOCaCOs).

6. The mineralization system of claim 1, wherein the powdered carbonates comprise powdered dolomite and the granular carbonates comprise granular calcite.

7. The mineralization system of claim 1, further comprising a plurality of valves, arranged to deliver a part of the water to the carbonates powder unit, deliver a the water exiting the carbonates powder unit with additional water into the granular

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carbonates unit, and mix the resulting water with a whole bulk of desalinated water.

8. The mineralization system of claim 6, further comprising a pH regulating module arranged to adjust a pH of the mixed water by adding a base thereto.

9. The mineralization system of claim 1, wherein the dolomite powder has a particle size of 5-75|-i, and the granular dolomite has a particle size of 2-5 mm.

10. The mineralization system of claim 1, wherein the injected acid is H2SO4 or HC1 and the dissolvable mineral compounds are CaSC>4 and MgSC>4 or CaCl2 and MgCl2, respectively.

11. A method comprising:

acidifying water,

introducing and mixing powdered carbonates into the acidic water to turn carbonates into dissolvable mineral compounds and CO2, wherein carbonates powder rests are left in the water as turbidity,

passing the water through a reactor with granular carbonates to dissolve additional mineral compounds and carbonate alkalinity upon reaction of the granular carbonates with the CO2, to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through the reactor, and recycling CO2 by removing CO2 from water exiting the reactor and introducing the removed CO2 into water entering the reactor.

12. The method of claim 10, further comprising using granular partially burnt dolomite (MgOCaCOs) as granular carbonates to elevate a necessary pH level for carbonates dissolution.

13. The method of claim 10, further comprising mixing the water exiting the reactor with a whole bulk of desalinated water.

14. The method of claim 12, further comprising adjusting a pH level of the mixed water by adding a base thereto.

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amendments to the claims have been filed as follows What is claimed is:

1. A water mineralization system comprising:

a carbonate powder unit comprising:

an acid injection unit arranged to acidify water,

a powder silo arranged to introduce carbonate powder into the acidified water, and a mixer arranged to mix the water with powdered carbonate to turn the carbonate into dissolvable mineral compounds and CO2, wherein powder rests are left in the water as turbidity, and a granular carbonate unit in fluid communication with the carbonate powder unit, arranged to receive the water therefrom and pass the water through a reactor with granular carbonate to dissolve additional mineral compounds and carbonate alkalinity upon reaction of the granular carbonate with the CO2, wherein the reactor is arranged to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through the reactor, the granular carbonate unit further comprising a CO2 recycling unit arranged to remove CO2 from water exiting the reactor and introduce the removed CO2 into water entering the reactor.

2. The mineralization system of claim 1, wherein the powdered carbonate comprises one of: powdered dolomite (CaMg(CC>3)2) and powdered calcite (CaCOs).

3. The mineralization system of claim 1, wherein the granular carbonate comprises one of: granular dolomite (CaMg(CC>3)2), granular partially burnt dolomite (MgOCaCOs) and granular calcite (CaCOs).

4. The mineralization system of claim 1, wherein the granular carbonate comprises one of: granular dolomite (CaMg(CC>3)2), and granular calcite (CaCOo.

5. The mineralization system of claim 1, wherein the granular carbonate comprises granular partially burnt dolomite (MgOCaCOs).

6. The mineralization system of claim 1, wherein the powdered carbonate comprises powdered dolomite and the granular carbonate comprises granular calcite.

7. The mineralization system of claim 1, further comprising a plurality of valves, arranged to deliver a part of the water to the carbonate powder unit, deliver the

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water exiting the carbonate powder unit with additional water into the granular carbonate unit, and mix the resulting water with a whole bulk of desalinated water.

11. A method comprising:

acidifying water,

introducing and mixing powdered carbonate into the acidic water to turn carbonate into dissolvable mineral compounds and CO2, wherein carbonate powder rests are left in the water as turbidity,

passing the water through a reactor with granular carbonate to dissolve additional mineral compounds and carbonate alkalinity upon reaction of the granular carbonate with the CO2, to dissolve powder rests and to filter non-dissolvable impurities of the turbidity during the passage of the water through the reactor, and recycling CO2 by removing CO2 from water exiting the reactor and introducing the removed CO2 into water entering the reactor.

12. The method of claim 10, further comprising using granular partially burnt dolomite (MgOCaCOs) as granular carbonate to elevate a necessary pH level for carbonate dissolution.