WO1995000443A1 - Process for the desalinization of sea water and for obtaining the raw materials contained in sea water - Google Patents

Process for the desalinization of sea water and for obtaining the raw materials contained in sea water Download PDF

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Publication number
WO1995000443A1
WO1995000443A1 PCT/CA1994/000350 CA9400350W WO9500443A1 WO 1995000443 A1 WO1995000443 A1 WO 1995000443A1 CA 9400350 W CA9400350 W CA 9400350W WO 9500443 A1 WO9500443 A1 WO 9500443A1
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Prior art keywords
flow
water
sea water
sodium
ions
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PCT/CA1994/000350
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French (fr)
Inventor
Irving W. Devoe
Original Assignee
Devoe Irving W
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Priority to US8144793A priority Critical
Priority to US08/081,447 priority
Application filed by Devoe Irving W filed Critical Devoe Irving W
Publication of WO1995000443A1 publication Critical patent/WO1995000443A1/en

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    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/4604Treatment of water, waste water, or sewage by electrochemical methods for desalination of seawater or brackish water

Abstract

A process and device for desalinating sea water is disclosed. The process first produces a stream of NaCl rich water by using a cascading flow through media. The second phase of the process is an electrozone which applies a voltage across this stream. NaOH produced in the electrozone regenerates the media in the first phase.

Description

PROCESS FOR THE DESALINIZATION OF SEA WATER AND FOR OBTAINING THE RAW MATERIALS CONTAINED IN SEA WATER

FIELD OF THE INVENTION

The invention relates to a process and a device for the desalination of sea water and for obtaining energy and the raw materials contained in sea water.

BACKGROUND OF THE INVENTION

According to the prior art, there are three basic methods for the desalination of sea water:

(1) obtaining water by changing its state, i.e. by evaporation or crystallization;

(2) desalination by electrolytic processes; and

(3) reverse osmosis.

The evaporation and distillation of water, for example, requires an energy input of approximately 25 to 30 kWh/m3 water~ and hence involves a high energy input, with the heat supplied being at least largely lost in the process. Distillation plants also have the disadvantage that they are exposed to a high risk of corrosion, making it necessary to replace the surfaces coming into contact with the sea water after 1 to 2 years. The productivity of these distillation plants is restricted to a maximum of 1000 3 per day.

The freezing process is based on the formation and growth of individual crystals on which only chemically homogeneous substances agglomerate, whereas foreign particles find no place in the lattice. The formation of inter-crystalline zones in which foreign particles can settle takes place in aqueous solutions when approximately 50% of the salt solution has changed into the solid state. The refrigeration units required for freezing in this way also operate at a low efficiency, and yet are very complex in terms of process technology. In any event, in practice the options described are relatively costly.

In the case of electrodialysis, the ions are extracted directly from the salt solution: the ions give up their charge and the metal atoms formed in this way settle on the cathode. This process is in principle applicable only for weak solutions,

SUBSTITUTE SHEET but not for the desalination of sea water, since the ion concentration is 105 per liter of solution. Attempts to reduce the ion concentration by using ion filters are unsuitable since these filters become unusable after a short time because of the ions deposited there. The problem of corrosion is also prominent in the case of electrolytic processes.

The reverse osmosis process also has technical disadvantages, since the water quantities produced in the largest experimental plants barely exceeds 1000 liters per day. In reverse osmosis, the salt solution is pressed through cellulose acetate membranes at pressures of 50 bar, or sometimes up to 100 bar. The mechanical stress on the membranes is correspondingly high. A disadvantage of this desalination method is that the membranes become unusable after a long period of use for various reasons, e.g. bacterial attack. Reverse osmosis admittedly has the advantage over the previously described methods that only small quantities of energy are used, by this cannot outweigh the disadvantages of low productivity and the danger of damage to the membranes.

Furthermore, the problems of energy supply in the future can by no means be regarded as solved. The combustion of fossil fuels produces carbon dioxide, of which the increasing proportions in the atmosphere bring the danger of very serious climatic consequences. The obtaining of energy by nuclear fission has created problems concerning the elimination of the radioactive waste. Obtaining energy from solar sources or by wind power devices admittedly has the advantage of producing no waste, but has to be regarded as a failure in economic terms.

Hence, there is still an urgent need for the creation of new sources of energy which can be used economically and without pollution of the environment.

In United States Patent No. 5,124,012, there is disclosed a process and device for the desalination of sea water and obtaining energy and the raw materials contained in sea water.

SUBSTITUTESHEET This invention is based on the principle of separating the ions contained in sea water using an electrostatic field into two separate solutions, each with ions of a given polarity, and conveying these to a conductor on which they are neutralized. The neutralized atoms are then further processed chemically to obtain hydrogen, alkaline lyes, earth alkaline lyes, earth alkaline metals and halogens.

In United States Patent No. 5,124,012, it is stated that according to the basic concept of the patented invention, oppositely charged ions are separated in an electrostatic field, without being neutralized. Studies by the present inventor indicates that counter-ions flow with the charged ions. For example, in the case of sodium, the counter ion is generally hydroxide, and in the case of chlorine, the counter ion is generally the hydrogen ion. Moreover, in the patented invention, extremely high voltages are applied to the plates. This requires the application of insulation onto the electrodes in order to prevent drawing arcs and discharging the electrodes through the water.

In United States Patent No. 4,176,023, there is disclosed a combined desalinization and extraction process for brinewater having a salinity of 7^% to 9%. The brinewater is introduced to a concentrator basically similar to a shell-and- tube type heat exchanger vertically arranged with upper and lower chambers above and below the tube section and communicating with each other through the tubes. A heating element in the lower chamber causes the brinewater to be heated until it reaches its boiling temperature. Vapors are removed from the upper chamber and are externally compressed so as to create a partial vacuum in the upper chamber. The compressed vapors are passed from the compressor to the concentrator into the spaces on the outside of the tubes where the vapors are condensed as liquid water. The condensed fresh water on the outside of the tubes is removed. The remaining brinewater within the tubes, which is concentrated at 28% salinity, is conducted to a plurality of electrolytic cells having positively charged anodes and negatively charged

SUBSTITUTE SHEET cathodes. The concentrated brine is electrolyzed with low voltage direct current to release chlorine gas, caustic alkali containing primarily sodium hydroxide, hydrogen gas, and an inert material containing calcium, nitrogen, and magnesium oxide. The chlorine gas is conducted to a mist extractor separator to remove any impurities and then compressed to form liquid chlorine. The hydrogen gas is conducted to a mist extraction separator to remove any impurities.

In United States Patent No. 4,176,023, a main disadvantage is that the system produces waste in the form of concentrated metals. A further disadvantage is that the water is produced essentially from a still which consumes high amounts of energy. The invention is also limited to solutions having 7%% salinity.

In United States Patent No. 4,233,134, there is disclosed the extraction of polar substances, such as pure water, from a solution containing such substances carried out in an electrical process that closely resembles natural evaporation. By exposing the solution to a closely spaced, electrically charged surface, the liquid molecules of the substance become sufficiently excited and attracted to break through the surface tension and migrate to the charged surface where they accumulate. Alternative embodiments disclose modified means for conveying the extracted substance from the treating area.

In United States Patent No. 4,510,026, there is disclosed the process of electrolysis of aqueous alkali metal halide solutions to produce hypohalite, halogen, halate and/or perhalate, the improvement comprising operating the electrolysis at least intermittently at a pressure less than 0.7 atmosphere, preferably sodium chloride solutions.

According to United States Patent No. 4,510,026, the electrolysis process or the desalinization of sea water presents many problems. First, the inventors state that both sea water and brine contain, in addition to chloride, other ions such as calcium and magnesium which tend to deposit on the cathode as hydroxides or carbonates during the hydrolysis. This presents

SUBSTITUTESHEET a problem in that scale formation around the electrodes hampers the process. The patent also remarks that the possibility of "softening" sea water or brine entering the system is not economically valid due to the large quantity of water which is treated. Still further, the patent requires that the electrolysis be conducted at least intermittently at a pressure of less than atmospheric pressure, i.e. less than 0.7 atmosphere.

There is, therefore, a great need in the art for a method and device for desalinating sea water, for producing deionized water for obtaining the raw materials contained in the sea water.

SUMMARY OF THE INVENTION

Accordingly, there is now provided with this invention an improved process and device for effectively overcoming the aforementioned difficulties and longstanding problems inherent in desalination. These problems have been solved in a simple, convenient, and highly effective way by which to desalinate sea water and to obtain the raw materials contained in the seawater. More particularly, a device is provided which desalinates sea water using electrodes having a high voltage yet which has a low energy utilization. Additional objects of the present invention will become apparent from the following description.

According to one aspect of the invention, a process is disclosed for desalinating a flow of sea water and for recovering raw materials contained therein. The process comprises removing non-sodium ions from the seawater flow thereby creating a flow of sodium chloride rich water. The process also comprises applying a voltage potential across the flow of sodium chloride rich water thereby creating a flow of sodium hydroxide rich water, a flow of hydrogen chloride rich water, and a flow of deionized water. The flow of sodium hydroxide rich water and the flow of hydrogen chloride rich water flows counter to the flow of the sodium chloride rich water and the flow of deionized water. The process further comprises recovering the flow of sodium hydroxide rich water, the flow of hydrogen chloride rich water, and the flow of deionized water.

SUBSTITUTESHEET As will be appreciated by those persons skilled in the art, a major advantage provided by the present invention is an economical method by which to desalinate water. It is, therefore, an object of the present invention to produce deionized water.

It is another object of the present invention to recover a flow of hydrogen chloride rich water from sea water.

It is still another object of the present invention to recover a flow of sodium hydroxide rich water from sea water.

It is a further object of the present invention to provide an economical and simple device for removing non-sodium ions from sea water.

It is a still further object of the present invention to provide an economical and simple device for producing deionized water from a flow of water which has been enriched in sodium chloride.

The method and apparatus of the present invention will be better understood by reference to the following detailed discussion of specific embodiments and the attached figures which illustrate and exemplify such embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

A specific embodiment of the present invention will be described with reference to the following drawings, wherein:

FIGURE 1 is a schematic representation of the water flow according to the present invention;

FIGURE 2 is an orthographic depiction of the troughs from which the water cascades for the removal of non-sodium ions from the sea water;

FIGURE 3 is an orthographic illustration of the structural building for housing the device illustrated in FIGURE 2;

FIGURE 4 is a side view of the trough from which the water cascades for the removal of non-sodium ions from the sea water;

SUBSTITUTESHEET FIGURE 5 is an orthographic illustration of the structural building for housing the device illustrated in FIGURE

4;

FIGURE 6 is a side view of the electrostatic device of the present invention;

FIGURE 7 is a top view of the electrostatic device of the present invention;

FIGURE 8 is an orthographic illustration of the preferred type of structure for having the cascading trough of the present invention;

FIGURE 9 is a plan view of the structure of FIGURE 8; and

FIGURE 10 is a section view of the structure of FIGURE 8 taken along section lines A-A of FIGURE 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The following preferred embodiment as exemplified by the drawings is illustrative of the invention and is not intended to limit the invention as encompassed by the claims of this application.

In FIGURE 1, the sea water 10 is shown drawn by a pipe 12 with a pump 14 connected thereto. The pump 14 pumps the sea water 10 to an elevation 16. From the elevation 16, the sea water may preferably pass through the entire process under gravity flow due to its hydraulic head, or alternatively, be pumped at different positions through the various stages of the process.

In the process schematically depicted in FIGURE 1, the first process step is generally illustrated by a cascading flow of water 18. The seawater first falls from the elevation 16 into a trough 20 located in the farthest upstream position. The trough 20 and the entire series of trough 22 are fixedly attached to an endless belt 24. Typically, the endless belt is chain- driven and has from about 5 to about 15 troughs positioned thereon. The troughs 22 are preferably about 2 feet deep and about 4 feet in diameter. The endless belt 24 is adapted to slowly rotate in a direction which is counter to the cascading

SUBSTITUTESHEET flow 18 and which is indicated by arrows 26. The endless belt 24 rotates in a direction of the arrows 26 much more slowly (for example, a few inches per minute) than the speed of the cascading flow 18.

The troughs 22 are more particularly illustrated in FIGURES 2 and 4 which illustrate a slotted screen 28 attached to each trough 22 and affinity medium 30 positioned therein. The affinity medium 30 is selected for preferentially binding with the non-sodium ions contained in the sea water 10. It has been found that such an ion exchange resin may be found as known by those skilled in the art as ClOO-Na as manufactured by Purolite Corporation. The slotted screen 28 is positioned on the troughs so that as the troughs rotate around the apex of the endless belt 24 and descend rightside up but in the same direction of the cascading water flow as shown by an arrow 32, the media positioned in the troughs does not fall out. One end of the trough is tipped downward for discharging the remainder of the water but for retaining the media. As shown generally in the FIGURES, each trough is preferably rounded at its bottom and the slotted screen 28 is preferably positioned at the leading edge 34 of the trough so as to retain the media 30 in the troughs.

As the water descends from above and cascades downward from an upstream trough to a downstream trough, the acceleration energy of the water keeps the particulate resins in suspension. By keeping the media in suspension, metals and other non-sodium ions are more efficiently removed from the sea water. The slotted screen which acts as a filter, keeps the media in the trough as the water flows through the screens and onto the next ascending downstream trough. The media are held in suspension of each step of the cascade. The turbulence of the water as it cascades downstream has been found to act as a self-cleaning mechanism for the screens. Alternatively, or in conjunction with the above described flow, and as shown in FIGURE 4, the water can be made to wash upward over the undersurface of the screens.

As an alternative to rotating the belt counter current to the sea water flow, one could also rotate the belt so that the

SUBSTITUTESHEET troughs move co-current with the direction of the sea water flow and in an opposite direction to the arrows 26 and 32. If the troughs are made to move in this alternative direction, the speed of the rotation of the troughs should preferably be slower than the speed of the cascading sea water flow. In this way, each trough will receive water from the trough above.

The resin media entering a trough is introduced by means of a pipe at the end of the trough. The media proceeds down the length of the trough during which times the resin is binding with and is preferably capturing metals or non-sodium ions, prior to exiting out a pipe at the opposite end of the trough. The residence times of the resins in the trough is determined by the pipe size and the flow rate through the pipes at the ends of the troughs. The metals, non-sodium ions, and other contaminants are removed from the sea water as the sea water flows downstream from an upstream trough to a downstream trough. The amounts of contaminants absorbed by the media is greatest if it is the lowermost or downstream most trough.

In either case, on the side 36 of the belt 24 where the troughs are inverted, the media can be preferably regenerated so that it will be fresh to remove metals, non-sodium ions, and other contaminants when the troughs next reach the sea water flow.

In a preferred mode of operation, the media can be washed continuously or at specific intervals using a sodium solution. The regeneration wash may be delivered to the inverted trough 36 by a line 38 as shown in FIGURE 1. As the sodium wash is delivered to the media, Ca++ and Mg++ are displaced therefrom due to the high Na+ concentration. Such a regenerative wash cycle is described in United States Patent No. 5,089,123, which is incorporated herein by reference.

The displaced Ca++, Mg++, metals, and other contaminants are then discharged by a pipeline 40. Alternatively, some of these discharged materials may be recaptured for another subsequent use of discharge if not practicable or desired. The water which is removed from the

SUBSTITUTE SHEET upstream most trough when the trough goes over the apex of the belt is redirected back into the sea water flow to elevation 16.

As illustrated in FIGURES 3 and 5, the series of troughs 22 positioned on the endless belt 24 are preferably constructed so as to simulate a Mayan pyramid, having from 1 to about 6 sides. The series of troughs thereby provide a series of spillways over which the water cascades from a central reservoir 42 as the top 44 of the pyramid.

The removal of magnesium, calcium, and potassium from sea water (and other metals of minor concentration in the cascading process is carried out in the following way. The ion exchange resin is first placed in the sodium form by applying sodium hydroxide or NaOH and HC1 to yield sodium chloride. (The sodium hydroxide is preferentially produced by the subsequent electrozone process as described below) .

The medium, in appropriate amounts [98 liters per 1000 liters of sea water] , is introduced into the downstream most trough 46 which represents the bottom step of the cascading system. As the sea water cascades down through the medium, magnesium and calcium are removed from the sea water by the medium.

If the sodium in the incoming sea water then displaces the magnesium or the calcium from its site on the medium, they are then freed to bind on other sites. However, the sodium ion, because it is in great excess, displace a sodium from the medium, the retardation of sodium downstream is only negligible because one sodium replaces another during the displacement. Therefore, the rate at which the magnesium and calcium will move downstream will necessarily be slower than the downstream rate of the water. When the movement of the medium in a counter flow direction is adjusted so that the net effect is that sodium and calcium are moved with the media upward on the cascading system while sodium chloride is allowed to cascade downward. The chloride in the sea water as a counter ion to magnesium and calcium remains in the downward stream and becomes the counter ion of sodium released from the medium.

SUBSTITUTESHEET The result, therefore, is a water stream exiting of the cascading system containing only sodium chloride.

Continuing to follow the flow of water downward, as illustrated in FIGURE 1, the cascading water eventually reaches the downstream-most trough 46, as explained above, the water at this point has been purged of the maximum amount of non-sodium ions, metals, and other contaminants.

In this way, a flowing stream has been produced which comprises a flow of sodium chloride rich water. After flowing over the downstream - most trough 46, the sodium chloride rich water reaches a collection basin 48.

The collection basin 48 may be positioned at an elevation so as to continue the gravitational flow of the sodium chloride rich water or be at another more convenient elevation, to which the sodium chloride rich water may be pumped. The sodium chloride rich water then flows out of the collection basin 48 through a pipe line 50 and into that stage in the process which is constructed for producing deionized water 52. This stage 52 is commonly referred to as an electrozone.

Generally, the electrozone 52 exposes the sodium chloride rich water flow to an electrical voltage. The stream is passed between plates, one of which is positive and one of which is negative, so that the sodium ion is attracted toward the negative electrode while the chloride ion is attracted towards the positive electrode. In practice, the sodium ion is followed by a hydroxyl ion which causes the pH immediately surrounding the cathode to go alkaline, whereas the pH surrounding the anode goes acid because chloride follows the hydrogen ion to that electrode.

The electrozone 52 is preferably constructed as an inverted trapezoid. The widest parallel side of the trapezoid 54 is the inlet side. The opposite side 56, that is, the smaller parallel side of the trapezoid is the outlet. The other two sloping sides of the trapezoid 58 and 60 are constructed so as to have electrodes 62 and 64. The electrozone 52 is constructed for providing a path for the sodium chloride rich water having maximum exposure to the electrodes 62 and 64. The electrodes 62 and 64 have opposite polarity and, as shown, electrode 62 is the cathode and electrode 64 is the anode. Of course, the side 58 could alternatively house the anode and side 60 could similarly house the cathode. The electrodes 62 and 64 have a high voltage potential therebetween. This potential may vary, but in practice, it has been found to be preferably in the range of from about 10 volts about 110,000 volts.

The voltage causes a "stacking" of ions near the electrode plates. For example, the sodium ion will concentrate around the cathode [negative plate] 62, whereas the chloride ion will concentrate around the anode [positive plate] 64. The sodium ion, although zoned with a higher concentration near the cathode 62, in response to its negative potential, is "followed" by the hydroxyl ion from the water. As a result, the pH at the anode 64 becomes very high, exceeding the ability of a standard pH electrode to measure the alkalinity [i.e. pH greater than 14].

Conversely, as the chloride ion is attracted to the anode 64 and concentrates there, it is followed by a proton from the water resulting in a drastic drop in pH (below 0) .

The result of this activity is the removal of salt from the water and the production of sodium hydroxide at one side 58 of the electrozone and hydrochloric acid at the other side 60 of the electrozone. In addition, some chlorine gas may be evolved as a product when the salt separated is a chloride anion. Exiting the electrozone 52 at the outlet of the trapezoid 56 is substantially deionized water 66.

As explained above, hydrogen chloride (hydrochloric acid) is produced at the anode side 60 of the electrozone. This is collected for possible future use in a collector 68. Similarly, the sodium hydroxide which is produced by the cathode side 62 of the electrozone is collected in a collector 70.

Preferably, not all of the sodium hydroxide that is produced is stored in the collector 70. A portion 72 of the NaOH stream is redirected. One portion of the redirected NaOH stream may be piped into the regeneration line 38 for regenerating the affinity media 30 in the troughs 22 on the inverted side 38 of the endless belt 24. Another portion 74 of the redirected NaOH stream 72 may be directed to a process 76 for regenerating previously used affinity media. The media regenerated in this process 76 may then be used to supplement or to replace the affinity media 30 in the troughs. The water stream 78 for the regeneration process 76 can then be discharged through a discharge line 78.

HC1 from the electrozone may also be combined with NaOH to make NaCl. A second anion exchange medium is therefore recycled when the chloride ion replaces other anionic species, for instance, A-100 medium as manufactured by Purolite Corporation. The chloride ion displaces the other anions and puts the medium in a chloride form (A-100-C1) .

In practice, other salts besides sodium chloride may be removed from sodium chloride rich water by the electrozone 52. For example, a sodium sulphate solution may be separated into Na+, on the other hand, and S04 " on the other. However, if divalent cations such as Mg++ or Ca++, were present in the entering water flow 50, they would precipitate at the higher pH's as hydroxide sludges on or around the cathode causing spalling of the apparatus.

It has been found that to facilitate the recovery of NaOH and HC1, the electrical potential on the plates is turned off for a short period of time [0.5 to 10 seconds] during which time the liquid around the plates is removed by pumping. It has been found that preferably the electrical potential on the plates is turned on and off [on - 5 to 10 seconds; off - 0.5 to 10 seconds] . This facilitates removal of sodium hydroxide and hydrochloric acid which would tend to stay in the area near the high voltage potential even with rapid movement of water during pumping.

The electrode plates are preferably spaced to minimize current through the electrolytic solution. Using the equation I=ER, where E is voltage, I is current, and R is resistance. The objective during electrozoning process is for I to approach O and R and E to approach equality. The ions and solutions are circulated in the electrozoning apparatus so that they are brought repeatedly in close proximity to the potential on the electrode plates. This may be accomplished by vigorous stirring or by lamellar flow as indicated by arrows 80 and 82.

The electrodes are maintained inside permeable membranes 84 and 86 or in a "stilling" compartment to avoid disturbing zoned ions with the agitation of the salt solution.

The objective in the case of sea water may be primarily to produce fresh water. The objective with industrial salt solutions which result from various industrial processes may be to recycle the acids and bases used in the process itself.

The electrode plates are preferably angled to keep E, R, and I constant as the electrolyte is depleted during its passage through the electrozoning apparatus.

Thus, the invention described herein provides a simple means to remove the salt from sea water resulting in deionized water and NaOH and HC1, plus Cl2, that can be used as final products for sale and for the production of all reagents required in the process of desalination of sea water.

For practical reasons, any mechanism for the desalination of sea water must be able to process large volumes of water, i.e. hundreds of millions of gallons per day. A prophetic example is as follows:

100,000 gp 144,000,000 gpd

144,000 x 62 gallons of media/1000 gallons of sea water

8,928,000 gallons of media per day.

892,800 gallons of media required if recycled lOx/day [2.4 hrs. per cycle]

892,800 x 3.785 L/gallons = 3,379,248 L media

1 acre = 4047 square meters [43,563 feet squared] 43563 feet cubed = 1233 meters cubed 1 acre foot = 1233 cubic meters [325,792 gallons/acre foot]

In the example, there are 422 acre feet per day produced at 100,000 gpm.

SUBSTITUTE SHEET TABLE 1

A. General Characteristics of Sea Water

0.4 M NaCl 0.05 M MgCl2 0.01 M CaCl2 0.01 M KC1

B. Molecular Waste

NaCl 48 Na = 23

MgCl2 94 Mg ■= 24

CaCl2 110 Ca = 40

KC1 75 K = 40 - Sea Water ΓKG/1000 L]

Na = 9.2 Kg

Mg = 1.2 Kg

Ca = 0.4 Kg

K = 0.4 KG D. Equivalents/1000L

Na =■ 400

Mg = 100

Ca = 20

K = 10

The preferred, but certainly not the only affinity medium in this process is C100-NA as manufactured by Purolite Corporation. ClOO-Na has 1.9 equivalents per liter in its most expanded condition. It is assumed that the sea water contains approximately 130 equivalents of metals other than sodium per 1000 liters. Therefore, 68.42 liters of C100 Na are required to remove the total amount of other cations from 1000 liters of sea water. To recycle C100 for regenerating the medium requires 130 equivalents of sodium. Assuming the medium is 70% efficient (i.e. as 70% of its sites occupied by Mg, Ca, and K, then 186 equivalents will be required to recycle the medium) . Therefore, the difference between 400 equivalents of sodium less then 186 equivalents required for recycling results in 215 equivalents remaining for the production of sodium hydroxide or hydrochloric acid for the subsequent electrozoning process.

SUBSTITUTE SHEET Although the particular embodiment shown and described above will prove to be useful in many industrial and municipal applications in the desalinating and ion recovery art to which the present invention pertains, further modifications of the present invention herein disclosed will occur to person skilled in the art. All such modifications are deemed to be within the scope and spirit of the present invention as defined by the appended claims.

SUBSTITUTESHEET

Claims

I CLAIM :
1. A process for desalinating a flow of sea water and recovering raw materials contained therein and for producing deionized water, comprising:
(a) removing non-sodium ions from the sea water flow thereby creating a flow of sodium chloride rich water;
(b) applying a voltage potential across said flow of sodium chloride rich water thereby creating a flow of sodium hydroxide rich water, a flow of hydrogen chloride rich water, and a flow of deionized water, wherein said flow of sodium hydroxide rich water and said flow of hydrogen chloride rich water flows counter to said flow of sodium chloride rich water and said flow of deionized water; and
(c) recovering said flow of sodium hydroxide rich water, said flow of hydrogen chloride rich water, and said flow of deionized water.
2. The process of Claim 1 wherein said removal of non- sodium ions comprises mixing the sea water flow with an affinity medium, wherein said affinity medium preferentially bonds with non-sodium ions.
3. The process of Claim 2, further comprising regenerating said affinity medium with said flow of sodium hydroxide rich water.
SUBSTITUTESHEET
4. A device for removing non-sodium ions from a flow of sea water, comprising:
(a) an endless rotating belt having a series of troughs positioned thereon, wherein said series of troughs move with said rotating belt between a sea water receiving position for sequentially receiving and discharging the flow of sea water from one trough to another and an inverted discharged position, and wherein said series of troughs have media positioned therein for preferentially binding with non-sodium ions as the sea water sequentially flows through said troughs when said troughs are in said sea water receiving position; and
(b) regeneration means for displacing the non-sodium ions bound to said media when said troughs are in said inverted position.
5. The device of Claim 4, wherein said belt rotates counter to the sea water flow, from downstream to upstream so that as said troughs move upstream, the sea water flows downstream from one trough to another.
6. The device of Claim 5, wherein said belt rotates co-current with the sea water flow and slower than the sea water flow so that as said troughs move downstream, the sea water flows downstream from one trough to another.
7. The device of Claim 4, wherein said regeneration means comprises a sodium solution and a pump for pumping said sodium solution through said troughs for regenerating said media.
8. The device of Claim 7, further comprising a non- sodium ion collecting device for collecting the displaced non- sodium ions.
SUBSTITUTESHEET
9. The device of Claim 7, further comprising means for collecting the sea water from the furthest upstream trough and for recycling the sea water from said upstream trough into the sea water flow before said regeneration means regenerates said media.
10. A device for producing deionized water from a flow of sodium chloride rich water, comprising:
(a) an inverted trapezoidal chamber having a wide parallel side positioned at the top of said chamber, a first angled side, and a second angled side depending from said wide parallel side, and a narrow side positioned on the bottom, wherein said narrow side is opposite and parallel to said wide parallel side and is connected to said first and said second angled sides, wherein said wide parallel side is the input to said chamber and said narrow parallel side is the exit of said chamber;
(b) a first electrode plate positioned proximate said first angled side of said chamber thereby creating a first channel therebetween;
(c) a second electrode plate positioned proximate said second angled side of said chamber thereby creating a second channel therebetween;
(d) a voltage source for applying voltage between said first electrode plate and said second electrode plate for creating a voltage potential therebetween and thereby creating a flow of sodium ions from the flow of sodium chloride rich water in said first channel and a flow of chloride ions in said second channel so that when the sodium chloride rich water enters said chamber and said voltage source is applied, said flow of sodium ions together with hydroxyl ions flow through said first channel counter to the flow of the sodium chloride rich water and said flow of chloride ions together with hydrogen ions flows through said second channel counter to the flow of the sodium chloride rich water thereby creating the flow of deionized water flowing out of said exit of said chamber.
11. A device of Claim 10, further comprising a first device for collecting said flow of sodium ions together with the hydroxyl ions for storing caustic product, and a second device for collecting said flow of chloride ions together with hydrogen ions for storing hydrochloric acid.
SUBSTITUTESHEET
PCT/CA1994/000350 1993-06-22 1994-06-22 Process for the desalinization of sea water and for obtaining the raw materials contained in sea water WO1995000443A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2262346A1 (en) 2009-06-10 2010-12-15 Nexans Use of oxide ceramic materials or metal ceramic compounds for electrical applications likes heaters
US8287710B2 (en) 2010-08-17 2012-10-16 King Fahd University Of Petroleum And Minerals System for electrostatic desalination

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT175215B (en) * 1950-12-11 1953-06-25 Ludwig Seibold Fa A process for desalination of liquids, in particular water
DE2559037A1 (en) * 1975-12-29 1977-07-07 Hermann Dr Behncke Desalting saline solns. - by electrolysing the soln. and removing purified water from the inter-electrode zone
US4772369A (en) * 1984-08-24 1988-09-20 Dominique Mercier Electromagnetic treatment of water
EP0291330A2 (en) * 1987-05-14 1988-11-17 Anglian Water Authority Ground-water treatment
US5089123A (en) * 1989-09-14 1992-02-18 Metanetix, Inc. Apparatus for continuous removal of materials from a liquid

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT175215B (en) * 1950-12-11 1953-06-25 Ludwig Seibold Fa A process for desalination of liquids, in particular water
DE2559037A1 (en) * 1975-12-29 1977-07-07 Hermann Dr Behncke Desalting saline solns. - by electrolysing the soln. and removing purified water from the inter-electrode zone
US4772369A (en) * 1984-08-24 1988-09-20 Dominique Mercier Electromagnetic treatment of water
EP0291330A2 (en) * 1987-05-14 1988-11-17 Anglian Water Authority Ground-water treatment
US5089123A (en) * 1989-09-14 1992-02-18 Metanetix, Inc. Apparatus for continuous removal of materials from a liquid

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2262346A1 (en) 2009-06-10 2010-12-15 Nexans Use of oxide ceramic materials or metal ceramic compounds for electrical applications likes heaters
US8287710B2 (en) 2010-08-17 2012-10-16 King Fahd University Of Petroleum And Minerals System for electrostatic desalination

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