Device and method for capturing and storing carbon dioxide from the atmosphere

Abstract

To provide a method for capturing carbon dioxide (CO2) from the atmosphere and an apparatus for carrying out the said method. [Solution] The present invention method comprises a process for obtaining a brine stream 1 and calcium carbonate 7, a process for generating an alkaline stream 5 containing sodium hydroxide (NaOH), and a process for generating an acidic stream 6 containing hydrochloric acid. One of the alkaline stream 5 and the acidic stream 6 is generated by electrochemical treatment of at least a portion of the brine stream 1. The present invention method further comprises a process for obtaining a liquid stream 8 of calcium chloride and a gaseous stream 9 of CO2 by neutralizing the hydrochloric acid by contacting the calcium carbonate 7 with hydrochloric acid in an acid reactor, and a process for generating a sodium carbonate stream 10 by contacting the NaOH from the alkaline stream generation process with CO2 from the neutralization process in a base reactor BR. The present invention method then comprises a process for releasing the sodium carbonate stream 10 into seawater or ocean water to increase the alkalinity of the seawater or ocean water and recovering CO2 from the atmosphere.

Description

[Technical Field]

[0001] The present invention relates to a device and method for capturing and storing carbon dioxide from the atmosphere. [Background technology]

[0002] Human activities have increased the concentration of carbon dioxide (CO2) in the atmosphere. Specifically, this increase is caused by the use of fossil fuels such as oil, gas, and coal, as well as deforestation and cement manufacturing.

[0003] Human activity contributes approximately two-thirds of the increase in atmospheric greenhouse gases due to the accumulation of CO2. For this reason, the impact of other greenhouse gases is conventionally measured in CO2 equivalents. In other words, an increase in CO2 concentration is considered equivalent to an increase in the overall concentration of greenhouse gases in the atmosphere. This increase is exacerbating global warming.

[0004] The concentration of carbon dioxide measured in the atmosphere in 2021 was 421 ppm. This concentration is dramatic, especially considering that it was only around 280 ppm in the mid-18th century. Therefore, the current CO2 concentration is a cause for concern among many scientists who strongly advocate for its negative impact on climate and the environment.

[0005] In recent years, new technologies have been explored to capture and store CO2 from the atmosphere to mitigate its adverse effects on the planet. Among these, introducing alkalinity into the ocean is considered a promising method for capturing and storing CO2.

[0006] European patent EP2024062 (Patent Document 1) discloses a method for recovering carbon dioxide from the atmosphere using an alkaline solution of NaOH.

[0007] Other methods, such as those using tronite (also known as tronite) or sodium sesquicarbonate dihydrate [Na3(CO3)(HCO3)·2(H2O)], are also being considered.

[0008] However, especially when considering applications for suppressing large-scale global warming, the prior art is not effective in terms of the CO2 balance and is unsatisfactory. Moreover, alkaline solutions are typically difficult to prepare, the raw materials for extraction methods are limited, and in those methods, pollutants are generated (especially because transportation is required).

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] The present invention improves this situation.

Means for Solving the Problems

[0011] That is, the present invention relates to a method for recovering carbon dioxide (CO2) in the atmosphere. The method of the present invention i a process of obtaining a salt water stream (1) and calcium carbonate (CaCO3) (7), and ii a process of generating an alkaline stream (5) containing sodium hydroxide (NaOH), and iii a process of generating an acidic stream (6) containing hydrochloric acid (HCl), and comprises.

[0012] In this method, at least one of the process ii of generating the alkaline stream (5) and the process iii of generating the acidic stream (6) includes a step of electrochemically treating at least a part of the salt water stream (1).

[0013] The method of the present invention further iv A process to obtain a liquid flow (8) of calcium chloride (CaCl2) and a gaseous flow (9) of carbon dioxide (CO2) by contacting the hydrochloric acid (HCl) obtained in process iii, which generates an acidic flow (6) to the calcium carbonate (CaCO3) (7) from acquisition process i, in an acid reactor (AR) to neutralize the hydrochloric acid (HCl), v A process to generate a sodium carbonate (Na2CO3) stream (10) by contacting at least a portion of the carbon dioxide (CO2) obtained in neutralization process iv with the sodium hydroxide (NaOH) from alkaline stream generation process ii in a base reactor (BR), vi A process to recover carbon dioxide (CO2) from the atmosphere by releasing the sodium carbonate (Na2CO3) stream (10) generated in the above process v into saltwater selected from seawater or ocean water to increase the alkalinity of the saltwater, It is equipped with.

[0014] In one embodiment, the saltwater stream in process i is obtained by taking in water selected from seawater or ocean water.

[0015] In one preferred embodiment, the electrochemical treatment is selected from the group consisting of electrodialysis and chlorine-alkali electrolysis.

[0016] In another preferred embodiment, the step iv of neutralizing the hydrochloric acid (HCl) further includes the recovery of the liquid stream (8) of calcium chloride (CaCl2).

[0017] In another preferred embodiment, the method further comprises steps upstream of steps ii and iii, which generate the alkaline flow (5) and the acidic flow (6). i.1 A process of obtaining a desalinated brine stream (1') on the one hand and a concentrated brine stream (2) on the other hand by desalting the brine stream (1) by reverse osmosis (RO), i.2 At least a portion of the concentrated brine stream (2) derived from reverse osmosis (RO) is received and purified (F), preferably selected from filtration and precipitation, from the concentrated brine stream (2) to Mg 2+Ions and Ca 2+ By removing ions, Mg 2+ Ions and Ca 2+ To obtain a purified water stream (2′) substantially free of ions and Ca ions, and Comprises.

[0018] In another preferred embodiment, the method further comprises, upstream of process ii for generating an alkaline stream (5) and process iii for generating an acidic stream (6), i.3 To obtain a purified water stream (2′) substantially free of Mg ions and Ca ions, and 2+ Ions and Ca 2+ To obtain a purified water stream (2′) substantially free of ions, and i.4 For generating the alkaline stream (5) of process ii for generating an alkaline stream (5) and the acidic stream (6) of process iii for generating an acidic stream (6), to perform electrodialysis by applying at least one electric field to the purified water stream (2′) substantially free of Mg ions and Ca ions, and 2+ Ions and Ca 2+ To perform electrodialysis by applying at least one electric field to the purified water stream (2′) substantially free of ions, and Comprises.

[0019] In this embodiment, the method further comprises, upstream of the electrodialysis process i.4, i.5 To obtain a desalinated water stream (1′, 11), preferably a filtered desalinated water stream (1′′), and to apply the electric field of the electrodialysis to the desalinated water stream (1′, 11), preferably the filtered desalinated water stream (1′′), to contribute to the generation of the alkaline stream (5) of process ii for generating an alkaline stream (5) and the acidic stream (6) of process iii for generating an acidic stream (6), May be provided.

[0020] Alternatively, the method of the present invention further comprises, upstream of process ii for generating an alkaline stream (5) and process iii for generating an acidic stream, i.6 Receiving the salt water stream (1) and removing Mg ions and Ca ions from the salt water stream (1) by purification (F), preferably selected from filtration and precipitation, to remove Mg ions and Ca ions, and 2+ Ions and Ca 2+ By removing ions, Mg 2+ Ions and Ca2+ The process of obtaining a purified water stream (2′) that contains virtually no ions, i.7 In order to generate the alkaline flow (5) in process ii and the acidic flow (6) in process iii, Mg 2+ Ions and Ca 2+ A process of electrodialysis in which at least one electric field is applied to the purified water stream (2′) which is substantially free of ions, and more preferably to the desalted water stream (11), It may also be equipped with.

[0021] In another alternative embodiment of the method of the present invention, the method further extends upstream of process ii, which generates the alkaline flow (5), and process iii, which generates the acidic flow. i.8 A process to obtain a desalinated water stream (1') and a concentrated salt water stream (2) by desalting the brine stream (1) by reverse osmosis (RO), i.9 A process of electrodialysis in which at least one electric field is applied to the desalinated water stream (1') and the concentrated brine stream (2) in order to generate the alkaline stream (5) in process ii and the acidic stream (6) in process iii, It may also be equipped with.

[0022] In some embodiments, in order to contribute to the generation of the alkaline flow (5) in process ii, which generates the alkaline flow (5), and the acidic flow (6) in process iii, which generates the acidic flow (6), a partially demineralized water flow (4) is also generated by electrodialysis and the partially demineralized water flow (4) is subjected to a second electrodialysis.

[0023] In another alternative embodiment, step ii of the method of the present invention for generating the alkaline flow (5) is: A sub-process by chlorine-alkali (CA) electrolysis generates the alkaline stream (5) containing sodium hydroxide (NaOH), a gaseous stream of dihydrogen (H2) (13), and a gaseous stream of chlorine (Cl2) (14). Process iii, which includes and generates an acidic flow (6), A side process to obtain a concentrated acidic stream (15) containing hydrochloric acid (HCl) and electricity and / or heat by injecting the gaseous stream (13) of dihydrogen (H2) and the gaseous stream (14) of chlorine (Cl2) into an H2 / Cl2 fuel cell (FC), and A sub-process to obtain the acidic stream (6) containing hydrochloric acid (HCl) is obtained by mixing the concentrated acidic stream (15) in a dilution tank (D) with a liquid, preferably saline liquid (16). Includes.

[0024] The present invention further relates to a device for recovering carbon dioxide (CO2) from the atmosphere, A means for taking in a saltwater stream (1), preferably seawater or ocean water, A means of preparing calcium carbonate (CaCO3) (7), The present invention relates to an apparatus that includes the following: An electrochemical processing unit (ED,U-CA) capable of generating an alkaline stream (5) containing sodium hydroxide (NaOH) and an acidic stream (6) containing hydrochloric acid (HCl) from at least a portion of the saltwater stream (1), An acid reaction apparatus (AR) that receives hydrochloric acid (HCl) by being in fluid communication with the electrochemical processing unit (ED,U-CA) and also receives calcium carbonate (CaCO3) (7) by being connected to the means that supplies calcium carbonate (CaCO3) (7), and generates a liquid flow (8) of calcium chloride (CaCl2) and a gaseous flow (9) of carbon dioxide (CO2) by bringing them into contact and neutralizing the hydrochloric acid (HCl), A base reactor (BR) that receives sodium hydroxide (NaOH) by being in fluid communication with the electrochemical unit (ED,U-CA) and receives carbon dioxide (CO2) by being in fluid communication with the acid reactor (AR), and generates a sodium carbonate (Na2CO3) flow (10) by bringing them into contact with each other, A means for recovering carbon dioxide (CO2) from the atmosphere by releasing the sodium carbonate (Na2CO3) stream (10) generated by the base reaction apparatus (BR) into saltwater selected from seawater or ocean water to increase the alkalinity of the saltwater, It is equipped with.

[0025] In one embodiment, the electrochemical processing unit (ED,U-CA) is selected from the group consisting of an electrodialysis machine and a salt electrolysis plant.

[0026] The apparatus of the present invention further, A reverse osmosis (RO) section is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2), The reverse osmosis (RO) section is in fluid communication with the concentrated brine stream (2) to receive at least a portion of the concentrated brine stream (2), and Mg 2+ Ions and Ca 2+ By removing ions, Mg 2+ Ions and Ca 2+ A purification section (F) is provided to obtain a purified water stream (2′) that is almost free of ions, It may also be equipped with.

[0027] In another embodiment, the apparatus further, Mg 2+ Ions and Ca 2+ A means of supplying a purified water stream (2′) that basically does not contain ions, The electrochemical processing unit comprises Mg 2+ Ions and Ca 2+ The electrodialysis apparatus (ED) is configured to generate the alkaline flow (5) and the acidic flow (6) by applying at least one electric field to the purified water flow (2'), which basically does not contain ions, through fluid communication with the means that supplies the purified water flow (2').

[0028] In this embodiment, the device further, Means for supplying a desalination water stream (1′,11), preferably a filtered desalination water stream (1′′), The electrodialysis apparatus (ED) may be configured to be in fluid communication with the means for supplying the desalinated water flow (1′,11,1′′), thereby applying the electric field to the flow to generate the alkaline flow (5) and the acidic flow (6).

[0029] Alternatively, the apparatus of the present invention may further include: A reverse osmosis (RO) section is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2). The electrodialysis apparatus (ED) may be equipped with such an electrochemical processing unit, which is in fluid communication with at least a portion of the desalinated water flow (1') and at least a portion of the concentrated brine flow (2), and is configured to generate the alkaline flow (5) and the acidic flow (6) by applying at least one electric field to them.

[0030] In another alternative embodiment of the present invention, the apparatus further comprises: A reverse osmosis (RO) section is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2), The reverse osmosis (RO) section is in fluid communication with the concentrated brine stream (2) to receive at least a portion of the concentrated brine stream (2), and Mg 2+ Ions and Ca 2+ By removing ions, Mg 2+ Ions and Ca 2+ A purification section (F) is provided to obtain a purified water stream (2′) that is almost free of ions, The electrochemical processing unit is equipped with, By being in fluid communication with the reverse osmosis section (RO), it receives at least a portion of the desalination water flow (1'), and by being in fluid communication with the purification section (F), it receives Mg 2+ Ions and Ca 2+A chlor-alkali reactor (CA) receives at least a portion of the purified water stream (2′) which is substantially free of ions, and applies at least one electric field to these streams (1′,2′) to generate the alkaline stream (5) containing sodium hydroxide (NaOH) (5), a gaseous stream (13) of dihydrogen (H2), and a gaseous stream (14) of chlorine (Cl2). By being in fluid communication with the salt electrolytic reactor (CA), the H2 / Cl2 fuel cell (FC) receives the gaseous flow (13) of dihydrogen (H2) and the gaseous flow (14) of chlorine (Cl2), thereby generating a concentrated acidic flow (15) containing hydrochloric acid (HCl) and electricity and / or heat, and A dilution tank (D) is provided to receive a liquid flow (1,16), preferably a brine flow, and to be in fluid communication with the H2 / Cl2 fuel cell (FC), thereby mixing the concentrated acidic flow (15) with the liquid flow (1,16) to generate the acidic flow (6) containing hydrochloric acid (HCl). It may also be a salt electrolysis plant that includes salts.

[0031] Other advantages and features of the present invention will become apparent upon consideration of the detailed description below and examination of the accompanying drawings. [Brief explanation of the drawing]

[0032] [Figure 1] This is a flowchart of a method according to a preferred embodiment of the present invention. [Figure 2] This is a flowchart of the method according to the second embodiment of the present invention. [Figure 3] This is a flowchart of the method according to the third embodiment of the present invention. [Figure 4] This is a flowchart of the method according to the fourth embodiment of the present invention. [Figure 5] This is a flowchart of the method according to the fifth embodiment of the present invention. [Figure 6] This is a flowchart of the method according to the sixth embodiment of the present invention. [Figure 7] This is a flowchart of the method according to the seventh embodiment of the present invention. [Figure 8] This is a flowchart of a method according to an alternative embodiment of the present invention. [Figure 9] This is a flowchart of a method according to another alternative embodiment of the present invention. [Modes for carrying out the invention]

[0033] Almost the entirety of the drawings, tables, and descriptions described below contains components of a particular nature. Each figure and table is an important part of the description, and thus may, as appropriate, contribute not only to understanding the present invention but also to defining it.

[0034] Generally speaking, the present invention can increase the alkalinity of inland seawater and / or ocean water. By increasing the alkalinity of a body of water, it becomes possible to better capture CO2 from the atmosphere and to better permanently store that CO2.

[0035] In short, the present invention relates to a device designed to increase the alkalinity of the sea or ocean. More specifically, in the present invention, an alkaline flow is released into seawater or ocean water (hereinafter referred to as seawater). This release promotes the return of the chemical properties of the seawater, such as its acidity (pH), to pre-industrial levels. This increases the capacity of the sea or ocean to capture, store, and sustainably retain CO2.

[0036] The present invention further relates to a method for obtaining an alkaline sodium carbonate solution and a neutralized solution using seawater and / or ocean water, electricity, and minerals (e.g., calcium carbonate). Both of these alkaline and neutralized solutions can be released into the sea and / or ocean to increase the alkalinity of the sea and / or ocean, thereby enabling the capture of CO2. The method of the present invention involves the intermediate formation of CO2, but the method controls this formation and reuses this gas at least partially within the method. In other words, one of the advantages of the present invention is that the overall problem of the method does not result in the generation of CO2 harmful to the environment or the generation of polluting waste.

[0037] Another advantage is that the raw materials used in the method of the present invention are abundant in nature. Specifically, these are seawater (more broadly, brine) and CaCO3. As a result, the work involved in carrying out the method of the present invention is simplified.

[0038] The seawater that this invention particularly targets is the seawater of the Baltic Sea and / or the Antarctic Ocean and / or the Indian Ocean and / or the Atlantic Ocean and / or the Pacific Ocean and / or the Mediterranean Sea and / or the Red Sea. For informational purposes only, 1 kg of seawater typically contains about 964.8 g of water (H2O) and 35.2 g of ionic compounds (mainly salts). Generally, these 35.2 g of ionic compounds contain approximately 19.352 g of chloride ions (Cl). - ), 10.784g sodium ions (Na + ), 2.712g sulfate ions (SO4 2- ), 1.284g magnesium ions (Mg 2+ ), 0.108g of bicarbonate ions (HCO3) - ), 0.412g calcium ions (Ca 2+ ), 0.399g potassium ions (K +), and the remainder consisting of other ions (see Zeebe and Wolf-Gladrow, 2001, CO2 in Seawater: Equilibrium, Kinetics, Isotopes, Gulf Professional Publishing).

[0039] In recent years, techniques for increasing the alkalinity of seawater by adding sodium carbonate (Na2CO3) have been investigated (see Hartmann et al., Stability of alkalinity in Ocean Alkalinity Enhancement (OAE) approaches - consequences for durability of CO2 storage, Biogeosciences Discuss., 2022 - DOI: 10.5194 / bg-2022-126). However, there are many challenges that must be overcome before large-scale methods using Na2CO3 can be implemented. In particular, the synthesis of Na2CO3 remains difficult. For this reason, prior art has focused more on methods using alkaline solutions such as sodium hydroxide (NaOH) solutions.

[0040] Despite the known difficulties, the applicants of this application focused their research on Na2CO3. One reason for this is that Na2CO3 is routinely used in industry for environmental hygiene purposes and is therefore not considered to pose a safety risk (see Brockmann and Janse, 2008, Calcium and carbonate in closed marine aquarium systems, Advances in coral husbandry in public aquariums, pages 133–142, chapter 14, Burgers' Zoo, Arnhem, The Netherlands).

[0041] Therefore, the applicant of this application has developed a method comprising multiple steps for capturing carbon dioxide (CO2) from the atmosphere. Specifically, the method of the present invention begins with a first group of steps for obtaining products essential to the technical effects of the present invention. That is, on the one hand, there is a step for obtaining a brine stream, and on the other hand, there is a step for obtaining calcium carbonate (CaCO3). In obtaining the brine stream, for example, brine may be taken in, or a brine solution may be produced by adding salts to water. Preferably, the brine is intended to be taken in directly from seawater, for example by a pump. In particular, when the apparatus of the present invention is to be installed in an already established plant structure, the brine stream may be derived from a mine or plant brine (industrial brine stream). CaCO3 is easy to obtain because it is one of the most abundant minerals on Earth. More specifically, CaCO3 makes up about 4% of the Earth's crust. Specifically, CaCO3 is found in rocks, mainly chalk, limestone, and marble.

[0042] The method further comprises a step of generating an alkaline stream, the alkaline stream generated in this step containing sodium hydroxide (NaOH). The method also further comprises a step of generating an acidic stream, the acidic stream in this step containing hydrochloric acid (HCl). In this invention, these generation processes can be carried out by electrochemical treatment. For this purpose, electrochemical treatment is performed on at least a portion of the brine stream pre-supplied in the acquisition step.

[0043] The method of the present invention further comprises a step of neutralizing the hydrochloric acid (HCl) produced in the step of generating the acidic flow. The hydrochloric acid (HCl) is neutralized by contacting it with calcium carbonate (CaCO3) obtained in the first step group of the method in an acid reactor (AR). As a result, a liquid flow of calcium chloride (CaCl2) and a gaseous flow of carbon dioxide (CO2) are obtained in the method according to this embodiment of the present invention.

[0044] In another embodiment, step iv, which neutralizes hydrochloric acid (HCl), involves the formation of CO2 from calcium carbonate (CaCO3) in the acidic solvent.2+ Ions, CO3 - This process is carried out in a manner that does not result in a superiority over simple dilution to ions.

[0045] The method further includes a step of generating a sodium carbonate (Na2CO3) stream. In the method according to the present invention, for this purpose, carbon dioxide (CO2) obtained by neutralization (or, in some cases, another gas from another source containing CO2 (see below)) is brought into contact with sodium hydroxide (NaOH) generated in the step of generating an alkaline stream in a base reactor (BR). This generates a sodium carbonate (Na2CO3) stream.

[0046] Finally, in the method of the present invention, this sodium carbonate (Na2CO3) stream is released into brine. The brine is seawater or ocean water. This increases the alkalinity of the water. This increases the capture of carbon dioxide (CO2) from the atmosphere.

[0047] The discharge into seawater may be direct or indirect. Specifically, indirect discharge involves discharging into a given flow within the plant, which is then carried to the sea where the discharge occurs.

[0048] Figure 1 is a flowchart of a method according to one embodiment of the present invention.

[0049] In this embodiment, the method begins with the inflow of seawater, ocean water, or more typically, brine 1 into a reverse osmosis (RO) system. This yields a desalinated water stream 1' and a concentrated brine stream 2. This concentrated brine stream 2 is sometimes referred to as a "rejected" stream containing the concentrated brine. It is possible to use reverse osmosis equipment from the FilmTec product range marketed by DuPont.

[0050] Part of waste flow 2 is Ca 2+ Ions and Mg 2+The ions are then sent to filter F, which removes most of the ions. This filter could be, for example, the PRO-XS2 nanofiltration membrane filter from Hydranautics or the FilmTec NF270 from Dupont. This removes the filtration residue 2' and the remaining Ca 2+ Ions and Mg 2+ A residue stream 3 containing a large amount of ions is obtained. When this residue stream 3 is discarded, Ca 2+ Ions and Mg 2+ Ions are removed.

[0051] In another embodiment, the filter is Ca 2+ Ions and Mg 2+ It may be replaced with a precipitation apparatus that removes most of the ions.

[0052] The filtered stream 2' flows into the electrodialysis machine ED. Optionally, if required by the specifications of the electrodialysis machine ED as in this embodiment, a portion of the desalinated water also flows in. Specifically, a three-circuit electrodialysis machine (EDBM) from PCCell GmbH or Eurodia can be used.

[0053] Three streams are discharged from the electrodialysis machine ED: (i) a partially demineralized water stream 4, (ii) an alkaline stream 5 containing NaOH, and (iii) an acidic stream 6 containing HCl. The partially demineralized water stream 4 can be removed or optionally repurposed for various uses, such as steam generation. If necessary, in one embodiment, a portion of the partially demineralized water stream 4 originating from the electrodialysis machine ED may be partially or entirely recirculated back into the electrodialysis machine ED.

[0054] Acidic flow 6 flows into reactor AR, referred to as the "acid reactor." CaCO3 is introduced into the acid reactor via supply path 7, neutralizing the HCl contained in acidic flow 6. Neutralization is carried out according to the following reaction equation: 2HCl + CaCO3 → CO2 + CaCl2 + H2O

[0055] In addition to this reaction, calcium carbonate can undergo a dissolution reaction (and acid neutralization) according to the following equation, either without forming CO2 or while consuming CO2: CaCO3 + CO2 + H2O(aq) → Ca 2+ +2HCO3 -

[0056] The aforementioned acid reaction apparatus and other neutralization equipment are specifically described in Maree and Plessis, 1993 (Kinetics of Calcium Carbonate Neutralization First-Order Case of the Cube-Root Law).

[0057] This yields a liquid stream 8 of calcium chloride (CaCl2) and a gaseous stream 9 of carbon dioxide (CO2). The CO2 stream 9 is carried to a reactor BR, referred to as the "base reactor." The alkaline stream 5 originating from the electrodialysis apparatus flows into the base reactor BR and reacts with the CO2 stream 9. A sodium carbonate (Na2CO3) stream 10 is obtained. The main reactions occurring in this reactor are substantially represented by the following reaction equation: 2NaOH + CO2 → Na2CO3 + H2O (partial neutralization of NaOH) and dilution in some cases.

[0058] NaOH can be partially neutralized using a CO2 injector available from Air Liquide. Dilution can be performed in a standard retention tank. In this way, the alkaline stream 5 can be diluted using the base reactor BR to obtain a stream 10 containing a high concentration of NaOH instead of Na2CO3.

[0059] In subsequent processes, this sodium carbonate (Na2CO3) flow 10 is released into seawater. More generally, this is done either directly or indirectly into brine.

[0060] This method can be implemented in either a continuous or batch manner, depending on the most appropriate method based on the available resources (e.g., seawater or brine, electricity, CaCO3, etc.).

[0061] Alternatively, the conditions of the steps for setting the residence time in the acid reactor AR may be controlled for the purpose of adjusting the generation of CO2. That is, the residence time is selected according to the concentration of the acidic flow 6 and the particle size of the calcium carbonate (CaCO3) particles 7.

[0062] The applicant of this application has considered several alternative embodiments to the preferred embodiments described above. These alternative embodiments are described below. Components (equipment, apparatus, etc.), and reaction formulas and / or chemical formulas and / or elements and / or flows that are given the same numerical, alphabetical or alphanumeric reference numerals refer to the same or similar elements.

[0063] Figure 2 is a flowchart of the method according to the second embodiment of the present invention.

[0064] This second embodiment of the method of the present invention does not involve reverse osmosis. In this case, the electrodialysis apparatus ED is configured to perform electrodialysis with the initial NaCl concentration of the brine stream (1) obtained at the beginning of the method. In this embodiment, the electrodialysis apparatus ED does not require a demineralized water stream (1'). Alternatively, a demineralized water stream (11) from another source may be obtained externally. From the step including electrodialysis onward, the method of this second embodiment is the same as the method described with reference to Figure 1.

[0065] Figure 3 is a flowchart of the method according to the third embodiment of the present invention.

[0066] This third embodiment of the method of the present invention does not include filtration. In this case, the salt-concentrated waste stream 2 or at least a portion thereof is subjected directly to electrodialysis, i.e., flows directly into the electrodialysis apparatus ED. This is because the electrodialysis apparatus ED is subjected to higher Ca 2+ Salt concentration and Mg 2+This means that it is designed to operate at a specific salt concentration. In all other respects, the method of this third embodiment is identical to the method described with reference to Figure 1.

[0067] Figure 4 is a flowchart of the method according to the fourth embodiment of the present invention.

[0068] In this fourth embodiment of the method of the present invention, the demineralized water 1' delivered from the reverse osmosis (RO) system is filtered by an additional filtration system F'. This additional filtration system F' filters out trace amounts of remaining Ca after reverse osmosis. 2+ Ions and Mg 2+ It is designed to remove all or almost all of the ions. That is, the demineralized water 1′ after reverse osmosis is transported to an additional filtration unit F′. This yields a filtered demineralized water stream 1′′, which is transported to the electrodialysis unit ED. The additional filtration unit F′ generates a waste demineralized water stream 12, which is typically disposed of. Alternatively, the waste demineralized water stream 12 may be recirculated to the base reactor BR, as shown in Figure 4, for the purpose of diluting the basic stream 10. In all other respects, the method of this third embodiment is the same as the method described with reference to Figure 1.

[0069] Figure 5 is a flowchart of the method according to the fifth embodiment of the present invention.

[0070] In this fifth embodiment of the method of the present invention, an electrochemical treatment step is provided in which a salt electrolysis (CA) type treatment is carried out. For this purpose, an electrochemical apparatus is used that outputs an alkaline stream 5 containing NaOH, a first gas stream 13 of dihydrogen (H2), and a second gas stream 14 of chlorine (Cl2). The alkaline stream 5 is delivered to a base reactor BR, as in the embodiment described with reference to Figure 1. The first gas stream 13 of H2 and the second gas stream 14 of Cl2 are injected into an H2 / Cl2 fuel cell FC. This yields a concentrated acidic stream 15 containing HCl, as well as electricity and / or heat (optionally used in this method). Alternatively, the H2 / Cl2 fuel cell FC may be replaced with a reactor that produces HCl without generating electricity.

[0071] Specifically, in this embodiment, it is possible to use a Chlor-pack type electrochemical apparatus manufactured by 3V-tech, a salt electrolysis electrode manufactured by De Nora, and a salt electrolysis membrane manufactured by Nafion.

[0072] The concentrated HCl acidic stream 15 is transported to a dilution tank D, where it is mixed with a liquid stream 16 (e.g., seawater, brine, etc.). This yields an acidic stream 6 that can be diluted with seawater. The dilution tank is a general-purpose tank designed to receive and dilute one or more liquids.

[0073] More generally, the dilution tank (D) is configured to receive a liquid stream (1,16), preferably a brine stream, more preferably a seawater stream. In another embodiment, the liquid stream may contain fresh water from, for example, a waterway, a river, or even a water supply.

[0074] Figure 6 is a flowchart of the method according to the sixth embodiment of the present invention.

[0075] In a sixth embodiment of the method of the present invention, electrodialysis is performed using a two-chamber bipolar membrane apparatus. Specifically, it is possible to use two-circuit EDBM apparatuses marketed by MEGA or Eurodia. Furthermore, it is possible to use CPM-CEM cell pairs marketed by REDstack BV and "spacers" marketed by Aqua Battery BV.

[0076] The electrodialysis machine generates an alkaline stream 5 containing NaOH and an acidic stream 6 containing HCl.

[0077] In this embodiment, unlike the other embodiments described above which include a different electrodialysis apparatus, a partial demineralized water flow 4 is not generated.

[0078] Figure 7 is a flowchart of the method according to the seventh embodiment of the present invention.

[0079] This seventh embodiment of the method of the present invention includes a step of introducing a liquid stream 17 (e.g., partially desalted seawater, brine, etc.) into the base reactor BR and the acid reactor AR. This allows for additional control over the two reactors (BR and AR).

[0080] In the above embodiment, each filter may be replaced with a precipitation device that removes most, if not all, of the target ions.

[0081] Furthermore, the calcium chloride (CaCl2) (flow 8) produced by the method of the present invention can be particularly repurposed for agricultural and food-related industries.

[0082] Furthermore, the present invention allows for scaling up the implementation because the acidic flow (HCl) from the electrochemical treatment process is neutralized. This is because if the acid is not neutralized in this way according to the present invention, a large amount of acid will be generated, making the method unsustainable when implemented at high capacity and / or in many geographical locations. If the acidic flow is not neutralized, it needs to be recovered or disposed of, but the amount of HCl present and the options for HCl disposal may limit the implementation of the method. In addition, to reduce transportation costs, a concentration process may be required before transporting HCl. Such a concentration process will increase the energy requirements of the method and CO2 emissions (particularly related to HCl transport). This will affect the efficiency of the method. Moreover, the transport of acids is typically a hazardous activity and is subject to restrictions by safety standards.

[0083] One of the further advantageous effects of the method and apparatus of the present invention is that it can be applied to various industrial fields (e.g., chemical, food, and pharmaceutical fields) that produce sodium carbonate and, more specifically, sodium bicarbonate.

[0084] In certain embodiments, the applicant has also provided the method and apparatus to recover at least partially carbon dioxide from the acid reactor AR.

[0085] Figure 8 is a flow chart of a method according to an alternative embodiment of the present invention. In this embodiment, the CO2 stream 9 is transported to its final destination and reused. What makes this embodiment particularly interesting is the purity of the CO2 produced in the acid reactor AR. As a result, the base reactor BR of this embodiment is supplied with CO2 by another gas stream 12. The gas stream 12 containing CO2 can be a pure stream containing 100% CO2 or a stream of lower purity (e.g., air, industrial fumes, etc.). The base reactor BR then produces a sodium carbonate (Na2CO3) stream 10, accompanied in parallel by a stream 13 corresponding to the emissions of the remaining elements in the gas stream 12.

[0086] Figure 9 is a flow chart of a method according to another alternative embodiment of the present invention, in which the CO2 stream 9 from the acid reactor branches off and is partially carried to the base reactor (BR) and partially carried to its final destination for reuse. Optionally, a portion of the stream 9 that is carried to the base reactor (BR) may be merged with a gaseous stream 12 (air) of lower purity CO2. The base reactor BR then generates a sodium carbonate (Na2CO3) stream 10, accompanied in parallel by a stream 13 corresponding to the exhaust of the remaining elements in the gaseous stream 12.

[0087] In other words, this alternative embodiment of the present invention can be defined as follows:

[0088] In methods for capturing carbon dioxide (CO2) from the atmosphere, a) The process of obtaining a saltwater stream (1) and calcium carbonate (CaCO3) (7), b) The process of generating an alkaline stream (5) containing sodium hydroxide (NaOH), c) The process of generating an acidic stream (6) containing hydrochloric acid (HCl), The method further comprises, wherein at least one of the steps b) for generating the alkaline flow (5) and c) for generating the acidic flow (6) includes a sub-step of electrochemically treating at least a portion of the brine flow (1), and the method further comprises, d) A process to obtain a liquid flow (8) of calcium chloride (CaCl2) and a gaseous flow (9) of carbon dioxide (CO2) by contacting the hydrochloric acid (HCl) obtained in process c) in an acid reactor (AR) to neutralize the hydrochloric acid (HCl), which is obtained in process a) from the calcium carbonate (CaCO3) (7) obtained in process a), e) A process to generate a sodium carbonate (Na2CO3) stream (10) by contacting the sodium hydroxide (NaOH) from the alkaline stream generation process b) with carbon dioxide (CO2), which may or may not be obtained in the neutralization process d), in a base reactor (BR), f) A process to recover carbon dioxide (CO2) from the atmosphere by releasing the sodium carbonate (Na2CO3) stream (10) generated in the above process e) into saltwater selected from seawater or ocean water to increase the alkalinity of the saltwater, A method characterized by comprising"

[0089] This description generally discloses that a sodium carbonate (Na2CO3) stream (10) can be released into brine selected from seawater and ocean water. Naturally, in each embodiment described, the sodium carbonate (Na2CO3) stream (10) may be released directly into the brine or indirectly. That is, the release may be carried out into brine contained in a tank provided for this purpose. Any brine can be modified by the apparatus and / or method of the present invention to capture carbon dioxide (CO2) from the atmosphere. The present invention can be implemented on land or within territorial waters (particularly on fixed or movable platforms).

[0090] This invention uses calcium carbonate (CaCO3). More specifically, within the scope of this invention, CaCO3 is a source independent of the method for capturing carbon dioxide (CO2) from the atmosphere. This is a so-called "third-party source." As mentioned above, the third-party source of CaCO3 can be rock, chalk, limestone, or marble. CaCO3 is one of the most abundant minerals on Earth, so it is easy to supply. The fact that the source of this component in this method is external is particularly advantageous from the standpoint of energy balance. This is because the method of this invention takes in CaCO3 from a natural source. Therefore, there is no need to synthesize CaCO3 by methods such as conversion or chemical synthesis, which typically produce CO2, which further degrades the atmosphere and is harmful to the energy balance.

[0091] In particular, the method of the present invention makes it possible to use marble without necessarily involving the storage solution of CO2 and / or the use of CO2. Specifically, thanks to the physical link between the acid reactor (AR) and the base reactor (BR), it becomes possible to transport a gaseous flow of carbon dioxide (9) and to use marble directly.

[0092] There are further advantages to using marble minerals, as they possess a high level of purity. Marble minerals contain iron (Fe, Fe + Fe 2+ These rocks have low levels of ) and typically do not contain heavy metals (especially nickel) that have adverse effects on ecosystems, such as those commonly found in silicate minerals.

[0093] In particular, the configuration of this method, which increases the alkalinity of seawater (referred to as "increased ocean alkalinity"), results in an energy balance that is superior to existing approaches. Prior art mainly concerns methods for directly recovering CO2 from seawater (referred to as "direct ocean recovery"). Direct CO2 recovery methods are fundamentally different from the present invention in that they release CO2 from seawater rather than directly treating it in situ in seawater. Therefore, direct recovery methods have problems with the storage and / or conversion of the recovered CO2. The present invention overcomes these problems.

Claims

1. Carbon dioxide (CO2) in the atmosphere ２ In a method for recovering ), i. Saltwater flow (1) and calcium carbonate (CaCO2) ３ The process of obtaining (7) and ii. The process of generating an alkaline stream (5) containing sodium hydroxide (NaOH), iii The process of generating an acidic stream (6) containing hydrochloric acid (HCl), The method further comprises, wherein at least one of the process ii for generating the alkaline flow (5) and the process iii for generating the acidic flow (6) includes a sub-step of subjecting at least a portion of the brine flow (1) to electrochemical treatment, and the method further comprises, iv. The calcium carbonate (CaCO3) obtained from the acquisition process i. ３ (7) The hydrochloric acid (HCl) obtained in the process iii of generating the acidic flow (6) is brought into contact with the acid reactor (AR) to neutralize the hydrochloric acid (HCl), thereby producing calcium chloride (CaCl ２ ) liquid flow (8) and carbon dioxide (CO ２ The process of obtaining the gas flow (9) of ) v The carbon dioxide (CO2) obtained in the neutralization process iv from the sodium hydroxide (NaOH) from the alkaline flow generation process ii. ２ By contacting at least a portion of ) in a base reactor (BR), sodium carbonate (Na) ２ CO ３ The process of generating the flow (10), vi The sodium carbonate (Na ２ CO ３ ) stream (10) generated in the above process v is discharged into salt water selected from seawater or ocean water to increase the alkalinity of the salt water, thereby recovering carbon dioxide (CO ２ ) in the atmosphere, and A method characterized by comprising:

2. A method according to claim 1, wherein the brine stream in process i is obtained by taking in water selected from seawater, ocean water or industrial brine.

3. A method according to claim 1 or 2, wherein the electrochemical treatment is selected from the group consisting of electrodialysis and salt electrolysis.

4. In the method according to any one of claims 1 to 3, the step iv of neutralizing hydrochloric acid (HCl) is further comprising calcium chloride (CaCl ２ A method comprising a sub-step of recovering the liquid flow (8) of the above.

5. The method according to any one of claims 1 to 4, further upstream of the process ii that generates the alkaline flow (5) and the process iii that generates the acidic flow, i. 1 A process to obtain a desalinated water stream (1') and a concentrated salt water stream (2) by desalting the brine stream (1) by reverse osmosis (RO), i.

2. At least a portion of the concentrated brine stream (2) derived from reverse osmosis (RO) is received, and the concentrated brine stream (2) is purified (F), preferably selected from filtration and precipitation, by which Mg ２＋ Ions and Ca ２＋ By removing ions, Mg ２＋ Ions and Ca ２＋ The process of obtaining a purified water stream (2') that contains virtually no ions, A method that includes [a certain feature].

6. The method according to any one of claims 1 to 5, further upstream of the process ii that generates the alkaline flow (5) and the process iii that generates the acidic flow, i. 3 Mg ２＋ Ions and Ca ２＋ The process of obtaining a purified water stream (2') that contains virtually no ions, i.

4. In order to generate the alkaline flow (5) in process ii, and the acidic flow (6) in process iii, Mg ２＋ Ions and Ca ２＋ A process of performing electrodialysis by applying at least one electric field to the purified water stream (2') which contains virtually no ions, A method that includes [a certain feature].

7. The method according to claim 6, further, upstream of the electrodialysis process i.4, i. 5 A process to obtain a demineralized water stream (1', 11), preferably a demineralized water stream (1'') after filtration, and to contribute to the generation of the alkaline stream (5) in process ii, and the acidic stream (6) in process iii, by applying the electric field of electrodialysis to the demineralized water stream (1', 11), preferably the demineralized water stream (1'') after filtration, A method that includes [a certain feature].

8. The method according to any one of claims 1 to 4, further upstream of the process ii that generates the alkaline flow (5) and the process iii that generates the acidic flow, i. 6 The brine stream (1) is received and purified (F), which is preferably selected from filtration and precipitation, to remove Mg ２＋ Ions and Ca ２＋ By removing ions, Mg ２＋ Ions and Ca ２＋ The process of obtaining a purified water stream (2') that contains virtually no ions, i. 7 In order to generate the alkaline flow (5) in process ii, and the acidic flow (6) in process iii, Mg ２＋ Ions and Ca ２＋ A process of electrodialysis in which at least one electric field is applied to the purified water stream (2') which contains virtually no ions, and optionally to the desalted water stream (11), A method that includes [a certain feature].

9. The method according to any one of claims 1 to 4, further upstream of the process ii that generates the alkaline flow (5) and the process iii that generates the acidic flow, i. 8 A process to obtain a desalinated water stream (1') and a concentrated salt water stream (2) by desalting the brine stream (1) by reverse osmosis (RO), i. 9 A process of electrodialysis in which at least one electric field is applied to the desalinated water flow (1') and the concentrated brine flow (2) in order to generate the alkaline flow (5) in process ii and the acidic flow (6) in process iii, A method that includes [a certain feature].

10. A method according to any one of claims 5 to 9, wherein a partially demineralized water flow (4) is also produced by electrodialysis and the partially demineralized water flow (4) is subjected to a second electrodialysis in order to contribute to the generation of the alkaline flow (5) in process ii for generating the alkaline flow (5) and the acidic flow (6) in process iii for generating the acidic flow (6).

11. In the method according to any one of claims 1 to 4, the process ii for generating the alkaline flow (5) is, By salt (C-A) electrolysis, the alkaline stream (5) containing sodium hydroxide (NaOH), dihydrogen (H) ２ ) gas flow (13), and chlorine (Cl ２ A sub-process that generates a gas flow (14) of ) Process iii, which includes and generates an acidic flow (6), H ２ / Cl ２ Fuel cells (FCs) use dihydrogen (H ２ ) the gas flow (13) and chlorine (Cl ２ By injecting the aforementioned gas stream (14) of ), a side process is obtained in which a concentrated acidic stream (15) containing hydrochloric acid (HCl) and electricity and / or heat are obtained, and A sub-process to obtain the acidic stream (6) containing hydrochloric acid (HCl) by mixing the concentrated acidic stream (15) with a liquid, preferably a saline solution (16), in a dilution tank (D). Methods that include...

12. Carbon dioxide (CO2) in the atmosphere ２ A device for recovering ) A means for taking in a saltwater current (1), preferably seawater or ocean water, Calcium carbonate (CaCO3) ３ ) (7) means to prepare, In a device comprising, An electrochemical processing unit (ED, U-CA) capable of generating an alkaline stream (5) containing sodium hydroxide (NaOH) and an acidic stream (6) containing hydrochloric acid (HCl) from at least a portion of the saltwater stream (1), By being in fluid communication with the electrochemical processing unit (ED, U-CA), it receives hydrochloric acid (HCl) and calcium carbonate (CaCO3). ３ (7) is connected to the means that supplies calcium carbonate (CaCO3). ３ ) (7) is received and brought into contact with each other to neutralize the hydrochloric acid (HCl), thereby producing calcium chloride (CaCl ２ ) liquid flow (8) and carbon dioxide (CO ２ An acid reactor (AR) that generates a gas flow (9) of ) By being in fluid communication with the electrochemical processing unit (ED, U-CA), it receives sodium hydroxide (NaOH), and by being in fluid communication with the acid reaction unit (AR), it receives carbon dioxide (CO2). ２ By receiving ) and bringing them into contact with each other, sodium carbonate (Na ２ CO ３ A base reaction apparatus (BR) that generates a flow (10), The sodium carbonate (Na) produced by the base reaction apparatus (BR) ２ CO ３ By releasing the (10) stream into saltwater selected from seawater or ocean water, the alkalinity of the saltwater is increased, thereby reducing the amount of carbon dioxide (CO2) in the atmosphere. ２ ) means of recovering, An apparatus characterized by comprising:

13. The apparatus according to claim 12, wherein the electrochemical processing unit (ED, U-CA) is selected from the group consisting of an electrodialysis machine and a salt electrolysis plant.

14. In the apparatus according to claim 12 or 13, further, A reverse osmosis (RO) section is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2), The reverse osmosis (RO) section is in fluid communication with the concentrated brine stream (2) to receive at least a portion of it, and Mg ２＋ Ions and Ca ２＋ By removing ions, Mg ２＋ Ions and Ca ２＋ A purification section (F) is provided to obtain a purified water stream (2') that is almost free of ions, A device equipped with the following features.

15. The apparatus according to any one of claims 12 to 14, further, Mg ２＋ Ions and Ca ２＋ A means for supplying a purified water stream (2') that contains virtually no ions, The electrochemical processing unit comprises Mg ２＋ Ions and Ca ２＋ An electrodialysis apparatus (ED) is configured to generate the alkaline flow (5) and the acidic flow (6) by applying at least one electric field to the flow (2') through fluid communication with the means that supplies the purified water flow (2') which is substantially free of ions.

16. In the apparatus according to claim 15, further, Means for supplying a desalination water stream (1', 11), preferably a filtered desalination water stream (1''), The apparatus is provided such that the electrodialysis apparatus (ED) is in fluid communication with the means for supplying a desalinated water stream (1', 11, 1''), and the electric field is applied to the stream to generate the alkaline stream (5) and the acidic stream (6).

17. In the apparatus according to claim 12, further, A reverse osmosis (RO) unit is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2). An electrodialysis apparatus (ED) comprising the electrochemical processing unit being in fluid communication with at least a portion of the desalination water flow (1') and at least a portion of the concentrated brine flow (2), thereby generating the alkaline flow (5) and the acidic flow (6) by applying at least one electric field to them.

18. In the apparatus according to claim 12, further, A reverse osmosis (RO) section is provided to receive the brine stream (1) and desalinate it to generate a desalinated brine stream (1') and a concentrated brine stream (2), The reverse osmosis (RO) section is in fluid communication with the concentrated brine stream (2) to receive at least a portion of it, and Mg ２＋ Ions and Ca ２＋ By removing ions, Mg ２＋ Ions and Ca ２＋ A purification section (F) is provided to obtain a purified water stream (2') that is almost free of ions, The electrochemical processing unit is equipped with, By being in fluid communication with the reverse osmosis (RO) section, it receives at least a portion of the desalination water flow (1'), and by being in fluid communication with the purification section (F), it receives Mg ２＋ Ions and Ca ２＋ By receiving at least a portion of the purified water stream (2') which is substantially free of ions, and applying at least one electric field to these streams (1', 2'), the alkaline stream (5) containing sodium hydroxide (NaOH) (5), dihydrogen (H) is converted. ２ ) gas flow (13), and chlorine (Cl ２ A salt electrolytic reactor (C-A) that generates a gas flow (14) of ) By being in fluid communication with the aforementioned salt electrolytic reactor (C-A), dihydrogen (H ２ ) the gas flow (13) and chlorine (Cl ２ By receiving the aforementioned gas stream (14) of ), a concentrated acidic stream (15) containing hydrochloric acid (HCl) is generated, and H generates electricity and / or heat. ２ / Cl ２ Fuel cell (FC), and It receives a liquid flow (1, 16), preferably a saltwater flow, and the H ２ / Cl ２ A dilution tank (D) is provided to be in fluid communication with a fuel cell (FC) and to generate an acidic flow (6) containing hydrochloric acid (HCl) by mixing the concentrated acidic flow (15) with the liquid flows (1, 16). A salt electrolysis plant containing (Na), or the equipment itself.

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