ES2358250B1 - DESALINATION OF SEA WATER BY SEQUENTIAL PRECIPITATION OF SEA SALTS, WITHOUT ENERGY CONSUMPTION AND REUSING REAGENTS. - Google Patents

Abstract

Desalination of seawater by sequential precipitation of sea salts, without energy consumption and reusing reagents. # In Fig. 1 we see how CO {sub, 2} and NH {sub, 3} are introduced into seawater, so that react giving rise to NH {sub, 4} Cl in solution and NaHCO {sub, 3} precipitate see fig.2. # By filtration we pass the NH {sub, 4} Cl to the next tank where it reacts with calcium bicarbonate Ca (HCO {sub, 3}) {sub, 2} see figure 3 to give CaCl {sub, 2} precipitate, CO {sub, 2} and ammonia gas that we will reinsert in the process. And we get fresh water Fig. 5. The precipitated CaCl {sub, 2} is reacted with the NaHCO {sub, 3} that comes from fig.2 in a separate tank with the minimum amount of water possible fig.6, to give a concentrated solution of NaCl, CO {sub, 2} gas that we will reuse and CaCO {sub, 3} precipitate fig. 7 # Filter and evaporate to obtain common salt. Subsequently, the CaCO {sub, 3} will be reacted along with the bicarbonate ion that comes from the addition of CO {sub, 2} to give the calcium bicarbonate solution fig.8 that we will reinsert in our cycle in fig.3.

Description

Desalination of seawater by sequential precipitation of sea salts, without energy consumption and reusing reagents.

Background of the invention

The present invention refers to the desalination of seawater, by a process of precipitation of sea salts that are dissolved in seawater, in different phases or sequences, to obtain fresh water, recovering the reagents used in the process and without energy cost.

This process represents a qualitative advance in the processes known so far, whose improvements affect energy saving and environmental pollution.

Object of the invention

Obtaining fresh water, for human consumption and for agricultural use, is a priority at the scientific level, to prevent the lack of water resources resulting in conflicts between communities and countries. The numerous technological processes that have sought the desalination of seawater as a natural source for obtaining fresh water are known, there are currently desalination processes by reverse osmosis and evaporation and distillation processes that aim at desalination. Investment costs, energy costs desalination. The energy costs of these systems and the economic cost of fresh water that is made available to farmers and users mean that these desalination systems have not been widely applied, especially in societies with few economic resources that are, perhaps , those who most need water resources for their development.

We must also highlight that the most widespread current technology in desalination of seawater, is reverse osmosis, whose process involves a high energy cost and produces significant contamination with the rejection brine, which, when poured into the sea, increases the marine salinity

To avoid the inconveniences of these technologies, the owner of the present invention has developed a process of desalination of seawater, which does not need energy to obtain fresh water, starting from a chemical physical process, which eliminates the ions of the sea salts, by means of a sequential precipitation, which allows to reduce the costs of the fresh water obtained. It does not produce rejection brine, and the dissolved ions in the seawater are removed, converting them into common salt. These characteristics are the object of the present invention.

Description of the invention

In a tower of dishes or reaction tank, we introduce the sea water, which we have previously filtered. In the dish tower or reaction tank, we add carbon dioxide (CO2) and ammonia (NH3), both in the form of gas. The CO2 is diluted in the water forming the bicarbonate ion (HCO3 -) and the ammonia (NH3) when diluted forms the ammonium ion (NH4 +). The reaction with the dissolved ions contained in seawater, and which are chlorine, sodium, calcium and magnesium, mainly react with the bicarbonate ion HCO3 - and ammonium NH4 +, to form ammonium chloride (NH4Cl), sodium bicarbonate (NaHCO3), calcium carbonate (CaCO3) and magnesium carbonate (MgCO3). Sodium bicarbonate NaHCO3, calcium carbonate CaCO3 and magnesium carbonate MgCO3 precipitate, leaving only the ammonium chloride NH4Cl. The sodium bicarbonate NaHCO3, the calcium carbonate CaCl2 and the magnesium carbonate MgCO3 precipitates are removed from the dish tower.

After this first precipitation sequence, only the NH4Cl ammonium chloride is dissolved in the water, which we pass to another reaction tank.

In this second tank we add to the solution calcium bicarbonate Ca (HCO3) 2 in solution, so that it reacts with the NH4Cl ammonium chloride.

In this reaction, the chlorine ion Cl - reacts with the calcium ion Ca2 +, to form the calcium chloride CaCl2 and the ammonia NH3 and the carbon dioxide CO2, after stirring and vacuum, are released in the form of gas, which is recovered and introduced again in the first reactor or dish tower.

The calcium chloride CaCl2 precipitates and is collected for reuse.

In this second sequence of precipitation, seawater has been free of chlorine ions Cl−, sodium Na +, calcium Ca2 + and magnesium Mg2 +, which is the highest concentration of saline ions it contains. Said fresh water, free of salts, is collected for use for agricultural use and for human consumption, prior to purification.

To recover the calcium bicarbonate Ca (HCO3) 2, as one of the reagents that are part of the process, we use two phases, which take place in two successive reaction tanks. In a first tank, we react, in aqueous solution, calcium chloride with sodium bicarbonate, to form:

CaCl2 + 2 NaHCO3 ------------------ 2 NaCl + CO2 + CaCO3

Carbonic anhydride (CO2) is released in the form of gas and we recover it for the next process.

The calcium carbonate (CaCO3) precipitates and is collected for the next phase and the sodium chloride (NaCl) that remains in saturated solution is removed from the tank so that by evaporation common salt is obtained.

In a second tank, the carbonic anhydride (CO2) is introduced into an aqueous solution to form the carbon ion (HCO3 -) and we add the calcium carbonate (CaCO3) obtained previously, to obtain the passage of calcium carbonate CaCO3 to calcium bicarbonate Ca ( HCO3) 2, which is soluble in water, according to the reaction:

CaCO3 + CO2 + H2O ------------- Ca2 + + 2 HCO3 -

Once obtained the calcium bicarbonate Ca (HCO3) 2 that is soluble in water, we will introduce it in the described reaction tank that only contains ammonium chloride (NH4Cl), so that they react in the following way:

Ca (HCO3) 2 + 2NH4Cl ----------- Ca Cl2 + 2CO2 + 2NH3

As we have already indicated, CO2 carbon dioxide and NH3 ammonia, by stirring and vacuum, are recovered as a gas, for the initial phase of the process. The calcium chloride CaCl2 is reused again for the second phase, where we react the sodium bicarbonate NaHCO3 with the calcium chloride CaCl2.

The process allows obtaining fresh water, recovering carbon dioxide CO2, ammonia NH3 and calcium bicarbonate Ca (HCO3) 2 which are the necessary reagents to eliminate dissolved ions in seawater.

Brief statement of the figure

In the fi g. 1 we see the development of the process. Thus (1) we see how CO2 and NH3 are introduced into seawater, so that they react giving rise to NH4Cl in solution and precipitated NaHCO3 (2).

By filtration we pass the NH4Cl to the next tank where it reacts with the calcium bicarbonate Ca (HCO3) 2 (3) to give precipitated CaCl2, CO2 and ammonia gas that we will reinsert in the process (4). And we get fresh water (5).

The precipitated CaCl2 is reacted with the NaHCO3 (2) in a separate tank with the minimum amount of water possible (6), to give a concentrated solution of NaCl, CO2 gas that we will reuse and precipitated CaCO3 (7).

We filter and evaporate to obtain common salt.

Subsequently, the CaCO3 will be reacted together with the bicarbonate ion that comes from the addition of CO2 to give the calcium bicarbonate solution (8) that we will reinsert into our cycle (3).

Description of the preferred embodiment

The desalination of seawater by sequential precipitation of sea salts, consists of two successive processes phases, with the purpose of obtaining fresh water and recovering the reagents used in the process. The first sequential phase is the reaction of carbon dioxide CO2 and ammonia NH3 both in the form of gas, for its reaction with salts that are dissolved in seawater. (one). Sodium bicarbonate NaHCO3, calcium carbonate CaCO3 and magnesium carbonate MgCO3, precipitate. The NH4Cl ammonium chloride, which is transferred to another reaction tank (2), remains in solution. Calcium bicarbonate Ca (HCO3) 2, in solution (3), is introduced into this reservoir so that it reacts by forming calcium chloride NH4Cl, which precipitates and releasing the carbon dioxide CO2 and the ammonia NH3 in the form of gas (4). The water that is in the solution is free of ions and, consequently, is fresh water, available for irrigation or prior purification, for human consumption. It is transferred to a warehouse for storage. (5).

The second phase consists in the recovery of the reagent used in the desalination that is calcium bicarbonate Ca (HCO3) 2. Carbon dioxide anhydride CO2 and ammonia NH3, has already been recovered in the previous phase in the form of NH3, has already been recovered in the previous phase in the form of gas.

For this, in another reaction tank, (6) we introduce the sodium bicarbonate NaHCO3 and the calcium chloride CaCl2, obtained as products resulting in the first process (4 and 2). The reaction of sodium bicarbonate NaHCO3 with calcium chloride CaCl2, produces sodium chloride NaCl and calcium carbonate CaCO3) releasing CO2 carbon dioxide in the form of gas. Said reaction is carried out in concentrated solution, to favor the reaction. The calcium carbonate CaCO3, precipitates and the sodium chloride NaCl is in the saturated solution, which we collect (7), by centrifugation, so that by evaporation it crystallizes as common salt.

We introduce the calcium carbonate CaCO3 into another reaction tank in aqueous solution and introduce the carbon dioxide anhydride obtained in the previous reaction (8). The calcium carbonate CaCO3, reacting with the bicarbonate ion HCO3 -, produced by dissolving the carbon dioxide CO2 in the water, is transformed into calcium bicarbonate that is soluble in water.

The calcium bicarbonate Ca (HCO3) 2, thus obtained, is introduced into the reaction tank (3), where the NH4Cl ammonium chloride, in solution, is found to start the process again.

The fundamental characteristics is that through sequential precipitation, the ions of the dissolved salts are eliminated, by precipitation, leaving the water free of salts. The process would be economically unfeasible if the elements involved in the process were not recycled, such as carbon dioxide CO2, calcium bicarbonate Ca (HCO3) 2 and NH3 ammonia. Therefore, the products obtained in the first phase, such as sodium bicarbonate NaHCO3 and calcium chloride CaCl2, are recycled and, from them, recover the reagents used according to the description already detailed.

The advantages of the system are unquestionable, with respect to current technology, because energy is not consumed as the reverse osmosis process. Common salt NaCl is obtained as a by-product, which crystallizes by evaporation, for use in the market, without polluting the environment, or salinizing the sea with brine. No external energy input is needed, as in the process of distillation or evaporation, so the production cost of the cubic meter of fresh water is much lower with the described system of sequential precipitation, than the systems currently used.

The materials used in the reaction tanks and in the components necessary for the transport of fluids between them, as well as the accessory shapes and dimensions and details, will be independent of the object of the invention, as long as they do not affect the essentiality.

Claims (3)

one.

Desalination of seawater by sequential precipitation of sea salts, without energy consumption and reusing reagents, consisting of the dissolution of carbon dioxide anhydride CO2 and ammonia NH3 in seawater, so that in its reaction with sodium ions Na + and chlorine Cl -, dissolved in seawater, NaHCO3 sodium bicarbonate and NH4Cl ammonium chloride are formed. NaHCO3 sodium bicarbonate precipitates and NH4Cl ammonium chloride remains in solution.

The ammonium chloride NH4Cl in solution is reacted with calcium bicarbonate Ca (HCO3) 2, in solution, so that in its reaction calcium chloride CaCl2 is formed, which precipitates and releases, by stirring and vacuum, the carbon dioxide CO2 and the NH3 ammonia in the form of gas, which is recovered for the previous process. The water is free of ions and consequently it is fresh water for agricultural use or human consumption.

2.

Desalination of seawater by sequential precipitation of sea salts, without energy consumption and reusing reagents, according to the preceding claims, consisting of recovering the reagents used, reacting, in aqueous solution, the sodium bicarbonate NaHCO3 with the calcium chloride CaCl2 , to obtain calcium carbonate CaCO3, sodium chloride NaCl and carbon dioxide CO2 in the form of gas. Said CO2 carbonic anhydride, previously dissolved, is reacted with the calcium carbonate CaCO3 to obtain calcium bicarbonate Ca (HCO3) 2 in solution.

SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 200902086 SPAIN Date of submission of the application: 26.10.2009 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: A61F2 / 54 (2006.01) A61F5 / 01 (2006.01) RELEVANT DOCUMENTS

Category

Documents cited Claims Affected

TO

US 4167044 A (IOWA STATE UNIVERSITY RESEARCH FOUNDATION, INC.) 11.09.1979, 1.16

columns 1-3; figures.

TO

US 2553277 A (ROBINSON et al.) 15.05.1951, columns 1-3; figures. 1.14

TO

JP 2007313093 A (UNIV OF SCIENCE TOKYO) 06.12.2007, summary; figures. one

TO

JP 2002345861 A (HARADA ELECTRONICS IND) 03.12.2002, summary; figures. one

TO

WO 2004021936 A1 (NORTH SIDNEY AREA HEALTH SERV et al.) 18.03.2004, page 18, one

line 17 - page 21, line 13; page 24, lines 9-33; page 40, line 23 - page 41, line 28;

Figures 26-29.41.

TO

WO 9921478 A1 (VIRTUAL TECHNOLOGIES INC) 06.05.1999, page 5, line 1 - page 7, one

line 5; page 10, lines 1-12; Figures 1A-2,12A, 13.

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 29.03.2011

Examiner J. Square Prados Page 1/4

REPORT OF THE STATE OF THE TECHNIQUE Application number: 200902086 Minimum documentation sought (classification system followed by classification symbols) A61F, B25J, A61H. Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC, WPI, PAJ, ECLA, UCLA. State of the Art Report Page 2/4  WRITTEN OPINION Application number: 200902086 Date of Written Opinion: 29.03.2011 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-16 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-16 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base. This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/4  WRITTEN OPINION Application number: 200902086 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 4167044 A 11.09.1979

D02

US 2553277 A 05.15.1951

D03

JP 2007313093 A 06.12.2007

D04

JP 2002345861 A 03.12.2002

D05

WO 2004021936 A1 03/18/2004

D06

WO 9921478 A1 06.05.1999

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The request refers to a drive device for a hand unable to be closed, in particular in a grabbing operation, so that the user of said device can, with the help of this device, close a sick hand to take, grab or grab some object and then reopen it. For this, the application presents a drive device for a disabled hand, of the type comprising means for moving, by means of an impulse from a mobile part of the user's body, one or more fingers of said disabled hand, from a first position in the that the hand is partially open to a second position in which said or said fingers have been retracted in the direction of the thumb, for the purpose of grasping or gripping an object, said actuator device comprising an exoskeleton applicable to the dorsal face of said hand. In the state of the art there are a variety of devices for actuation either for a prosthesis (artificial hand, for example) or for orthoses or external devices that coupled on a user's disabled hand allow or facilitate the movement or functionality of the same. There are also devices of the Continuous Passive Motion-CPM type, which are preferably used for rehabilitative purposes, or even exoskeletons attached to a hand that, sometimes for other purposes, are similar to the device presented in the application. Documents D01 to D06 cited in the Report only show the general state of the art and are not considered of particular relevance. Documents D01 to D04 are of the type provided for operating a disabled hand and ensuring its functionality. Of these, documents D01 and D02 are driven by a pulse from a mobile part of the user's body, as in the case of the request device. Document D05 foresees a possible application for rehabilitative therapy by means of CPM, and also foresees its possible use to provide functionality at the hand of a patient with an impaired function (page 18, lines 16-22). Finally, document D06 is a representative of a type of exoskeleton used with a different function (measuring the position of the fingertips and determining the angles of your joints) that can be applied in areas such as virtual reality , tele-robotics, graphic animation or in the medical assessment of hand functioning. Any of these documents presents some devices that anticipate solutions that can be considered similar to those of the actuation device of a disabled hand that occupies us, or show a structure that has some resemblance to it, but none of them anticipate all the features which limit the object of protection the first main claim. Thus, the documents cited only show the general state of the art, and are not considered of particular relevance. It would not be obvious for a person skilled in the art to apply the features included in the cited documents and arrive at the invention as disclosed in the first claim. Therefore, the object of this main claim meets the requirements of novelty and inventive activity. Dependent claims 2 to 16 delimit additional optional features and as the first general also meet the requirements regarding novelty and inventive activity. State of the Art Report Page 4/4