Direct air capture apparatus using dry carbon dioxide absorbent

Abstract

A direct air capture apparatus using a dry carbon dioxide absorbent, according to one embodiment of the present invention, comprises: a dry carbon dioxide absorbent formed in a pebble shape having a predetermined size; and a direct air capture (DAC) reactor that replaceably accommodates the dry carbon dioxide absorbent within a mesh-like structure and absorbs and captures carbon dioxide from air by bringing the dry carbon dioxide absorbent into contact with the air.

Description

Direct air capture device using dry carbon dioxide absorbent

[0001] The present invention relates to a direct air capture device using a dry carbon dioxide absorbent, and more specifically, to a direct air capture (DAC) device that converts the concentration of carbon dioxide in the outdoor or indoor environment to a level harmless to the human body by directly capturing carbon dioxide from the air using a dry carbon dioxide absorbent and then releasing it back outdoors or indoors, thereby maintaining the surrounding air in a pleasant state at all times and contributing to the improvement of the user's health, as well as contributing to the response to global climate crises such as global warming by recycling the captured carbon dioxide for resource production.

[0002] Recently, in response to the climate crisis, there has been an international trend of further strengthening carbon regulations, such as declaring carbon neutrality goals to curb atmospheric emissions of carbon dioxide and capture carbon dioxide that has already been emitted. Korea is also keeping pace with the efforts of the international community by declaring carbon neutrality by 2050 and creating an atmosphere to induce a transition to a low-carbon and eco-friendly economic structure.

[0003] To solve these problems, this corresponds to the technology field of capturing carbon dioxide that has already been emitted into the atmosphere—among the methods currently being pursued as an important reduction means to achieve national greenhouse gas reduction targets—which reduces the concentration of carbon dioxide in the atmosphere and utilizes the captured carbon dioxide as a resource.

[0004] Among these, the latter technology for removing carbon dioxide that has already been emitted into the air is generally referred to as Direct Air Capture (DAC) technology. More specifically, it refers to a technology for mitigating the greenhouse effect by reducing the concentration of carbon dioxide, a greenhouse gas in the air, through various methods such as chemical adsorption using various media like alkaline solutions and physical adsorption using various catalysts.

[0005] Typically, such Direct Air Capture (DAC) technology may consist of carbon dioxide absorbent manufacturing technology, absorbent reaction technology with CO2, and regeneration technology for absorbents saturated with CO2.

[0006] In addition, representative technologies for removing carbon dioxide from the air using the above-mentioned absorbent include the wet alkali method, which produces carbonates through a chemical reaction with carbon dioxide in a solution state, and the wet amine method, which removes carbon dioxide by combining it with nitrogen atoms in a solution state.

[0007] However, as described above, conventional methods for removing carbon dioxide from the air in a solution state had problems in terms of economic feasibility, such as low absorption performance of 2 mmole / g or less, high regeneration temperatures of 300 to 900°C, and degradation of the absorbent due to frequent absorption and regeneration processes. In addition, in terms of environmental feasibility, there were problems such as the possibility of secondary contamination by harmful substances that may occur during the carbon dioxide removal process, such as the evaporation and leakage of alkaline solutions in the case of wet methods and the leakage of alkali or amines during the regeneration process in the case of dry methods.

[0008] Accordingly, the present invention has been devised to resolve the aforementioned problems and aims to provide a Direct Air Capture (DAC) device using a dry carbon dioxide absorbent that can contribute to the improvement of user health by maintaining the surrounding air in a pleasant state at all times, by converting the outdoor or indoor carbon dioxide concentration to a level harmless to the human body through Direct Air Capture (DAC) using a dry carbon dioxide absorbent and then releasing it back outdoors or indoors, while also contributing to the response to global climate crises such as global warming by recycling the captured carbon dioxide for resource production.

[0009] According to one embodiment, a direct air capture device using a dry carbon dioxide absorbent of the present invention for achieving the above-mentioned purpose comprises: a dry carbon dioxide absorbent manufactured in the form of a pebble of a certain size; and a Direct Air Capture (DAC) reactor that replaceably accommodates the dry carbon dioxide absorbent within a mesh structure and absorbs and captures carbon dioxide from the air by bringing the dry carbon dioxide absorbent into contact with air.

[0010] In addition, according to one embodiment, the dry carbon dioxide absorbent is manufactured by the following steps: (S100) preparing a dry absorbent material; (S200) mixing and reacting the dry absorbent material to form a dry absorbent paste; (S300) extruding and molding the dry absorbent paste to form a dry absorbent pebble of a certain size; (S400) firing the dry absorbent pebble in a kiln; and (S500) hydrating the fired dry absorbent pebble to complete the manufacture of the dry absorbent.

[0011] In addition, according to one embodiment, the dry absorbent powder of step (S100) is characterized by being formed by mixing a silicate mineral, a carbonate mineral, water glass, a basic alkali mixture, and an additive.

[0012] In addition, according to one embodiment, the basic alkali mixture comprises: one or more oxides selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3; one or more metals selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; a crystallized synthetic zeolite prepared from an alumina-based raw material, a silica-based raw material, and sodium hydroxide; and one or more liquid compositions selected from the group consisting of sodium tetraborate (Na2B4O7·10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3), potassium hydroxide (KOH), and hydrogen peroxide (H2O2).

[0013] In addition, according to one embodiment, the additive comprises at least one of biochar, lignocellulosic biomass, silica gel, potassium hydroxide (KOH), sodium hydroxide (NaOH), and silicon dioxide (SiO2).

[0014] Additionally, according to one embodiment, the DAC reactor comprises: an inner casing having a mesh-like structural shape and replacingably accommodating the dry carbon dioxide absorbent; and an outer casing that surrounds and protects the periphery of the inner casing while providing an air passage so that air introduced from one side can come into contact with the dry carbon dioxide absorbent accommodating the inner casing and then be discharged to the other side.

[0015] Additionally, according to one embodiment, the inner box comprises: an inner box support installed at a certain distance from the floor surface of an outdoor or indoor space; and an inner box body having a plurality of through holes formed on the entire circumference of a cylindrical or polygonal tube body containing a dry carbon dioxide absorbent, and selectively seated on the inner box support.

[0016] Additionally, according to one embodiment, the outer casing comprises: an outer casing support provided around the circumference of the inner casing support to surround the inner casing support; and an outer casing body integrally formed on the outer casing support and having a plurality of through holes formed so that air can be introduced into or discharged from at least a portion of a cylindrical or polygonal tubular body.

[0017] In addition, according to one embodiment, the top of the enclosure is opened, and an upper cover is further provided on the open top of the enclosure, thereby selectively opening and closing the open top of the enclosure.

[0018] In addition, according to one embodiment, a lower protective cover is further provided at the bottom of the enclosure to completely surround and protect the enclosure support.

[0019] In addition, according to one embodiment, the inner box support comprises: an inner box mounting plate on which the inner box body is supported; and a leg portion that supports the inner box mounting plate so as to be spaced a certain distance from the floor surface of an outdoor or indoor space.

[0020] In addition, according to one embodiment, a cover bracket is further provided on the top of the outer body so that an upper cover can be optionally fitted and seated thereon.

[0021] In addition, according to one embodiment, the upper cover is further equipped with a lighting light, a CO2 sensor, and a communication module.

[0022] In addition, according to one embodiment, the upper cover is further equipped with a photovoltaic power generation module to supply power to the lighting, CO2 sensor, and communication module.

[0023] The present invention, as described above, can achieve the world's highest level of carbon dioxide absorption (capture) performance of 2.4 mmol / g or more (which corresponds to a performance level that is much higher than the current level, meaning that 26.4g of carbon dioxide can be captured per 100g of dry absorbent) by using a dry carbon dioxide absorbent, and at the same time, by desorbing carbon dioxide at a low temperature, there is no degradation of the absorbent, and the energy required is low, thereby improving economic efficiency, and at the same time, no environmentally harmful substances are generated, thus having an eco-friendly effect.

[0024] In addition, the carbon dioxide adsorbed through this invention can be recycled for the production of useful resources, thereby contributing to overcoming the climate crisis related to global warming.

[0025] FIG. 1 is a perspective view of a direct air collection device using a dry carbon dioxide absorbent of the present invention according to one embodiment.

[0026] FIG. 2 is an exploded perspective view of FIG. 1.

[0027] FIG. 3 is a longitudinal section of FIG. 1.

[0028] FIG. 4 is a cable connection diagram of a lighting and communication assembly according to the present invention.

[0029] FIG. 5 is a graph of the carbon dioxide absorption and regeneration cycle operation according to the present invention.

[0030] FIG. 6 is a photographic image of a dry carbon dioxide absorbent pebble manufactured according to one embodiment of the present invention.

[0031] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “having,” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described herein, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] Unless otherwise defined in this specification, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains.

[0033] Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0034] Hereinafter, with reference to the attached drawings, the configuration and operational relationship of a direct air collection device using a dry carbon dioxide absorbent according to one embodiment of the present invention will be examined in detail as follows.

[0035] FIG. 1 is a perspective view of a direct air collection device using a dry carbon dioxide absorbent according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, FIG. 3 is a cross-sectional view of FIG. 1, FIG. 4 is a cable connection diagram of a lighting and communication assembly according to the present invention, FIG. 5 is a graph of the carbon dioxide absorption and regeneration cycle operation according to the present invention, and FIG. 6 is a photographic image of a dry carbon dioxide absorbent pebble manufactured according to one embodiment of the present invention.

[0036] First, according to one embodiment, the direct air capture device using the dry carbon dioxide absorbent of the present invention is largely composed of: a dry carbon dioxide absorbent manufactured in the form of a pebble of a certain size (hereinafter referred to as 'dry KLC'); and a DAC (Direct Air Capture) reactor that replaceably accommodates the dry carbon dioxide absorbent within a mesh structure and absorbs and captures carbon dioxide in the air by bringing the dry carbon dioxide absorbent into contact with air.

[0037] According to one embodiment, the dry carbon dioxide absorbent (dry KLC) is manufactured by the following steps: (S100) preparing a dry absorbent material; (S200) mixing and reacting the dry absorbent material to form a dry absorbent paste; (S300) extruding and molding the dry absorbent paste to form a dry absorbent pebble of a certain size; (S400) calcining the dry absorbent pebble in a kiln; and (S500) hydrating the calcined dry absorbent pebble to complete the manufacture of the dry absorbent.

[0038] In addition, according to one embodiment, the dry absorbent powder of step (S100) is formed by mixing a silicate mineral, a carbonate mineral, water glass, a basic alkali mixture, and an additive.

[0039] In addition, according to one embodiment, the basic alkali mixture comprises: one or more oxides selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3; one or more metals selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; a crystallized synthetic zeolite prepared from an alumina-based raw material, a silica-based raw material, and sodium hydroxide; and one or more liquid compositions selected from the group consisting of sodium tetraborate (Na2B4O7·10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3), potassium hydroxide (KOH), and hydrogen peroxide (H2O2).

[0040] In addition, according to one embodiment, the additive comprises at least one of biochar, lignocellulosic biomass, silica gel, potassium hydroxide (KOH), sodium hydroxide (NaOH), and silicon dioxide (SiO2).

[0041] A dry carbon dioxide absorbent (dry KLC) according to the present invention can be formed as disclosed in FIG. 7 by the steps described above.

[0042] Meanwhile, referring to FIGS. 1 to 4, according to one embodiment, the DAC reactor (1000) comprises: an inner casing (1100) having a mesh-like structural shape and replacingably accommodating the dry carbon dioxide absorbent; and an outer casing (1200) that surrounds and protects the inner casing while providing an air passage so that air introduced from one side can come into contact with the dry carbon dioxide absorbent accommodating the inner casing and then be discharged to the other side.

[0043] Additionally, the inner container (1100) comprises: an inner container support (1110) installed at a certain distance from the floor surface of an outdoor or indoor space; and an inner container body (1120) having a plurality of through holes formed on the entire circumference of a cylindrical or polygonal tube containing a dry carbon dioxide absorbent, and selectively seated on the inner container support (1110).

[0044] Additionally, the outer casing (1200) comprises: an outer casing support (1210) provided around the inner casing support (1110) to surround the inner casing support (1110); and an outer casing body (1220) integrally formed on the outer casing support, having a plurality of through holes, i.e., air inlet holes (1200a), formed so that air can be introduced into at least a part of a cylindrical or polygonal tube.

[0045] Additionally, as the top of the outer body (1220) is opened, an upper cover (1300) is provided on the open top of the outer body (1220). At this time, the upper cover (1300) selectively opens and closes the open top of the outer body (1220).

[0046] Additionally, the upper cover (1300) has an air discharge hole (1300a) formed therein so that air introduced through the air inlet hole (1200a) of the outer body (1220) can be discharged to the outside of the outer body (1200) after coming into contact with the dry carbon dioxide absorbent (dry KLC) contained in the inner body (1100).

[0047] That is, since the air inlet hole (1200a) is located close to the floor surface of the interior or exterior and the air outlet hole (1300a) is located above the air inlet hole (1200a), the air introduced into the air inlet hole (1200a) at the bottom of the enclosure body (1220) comes into contact with the dry carbon dioxide absorbent (dry KLC), removes carbon dioxide, moves upward, and is discharged through the air outlet hole (1300a) by natural convection. Therefore, as in the above-described embodiment, the DAC reactor (1000) of the present invention can be operated by a power-free natural convection method without a fan for forced circulation.

[0048] Additionally, a lower protective cover (1500) is provided at the bottom of the outer casing body (1220) to completely surround and protect the outer casing support (1210). At this time, a hollow (1500a) is formed in the center of the lower protective cover (1500), and when installing the lower protective cover (1500), the installation is completed by inserting the hollow (1500a) from the top of the outer casing body (1220) and lowering it to the bottom of the outer casing body (1220).

[0049] Additionally, the inner box support (1110) comprises: an inner box mounting plate (1111) on which the inner box body (1120) is supported; and a leg portion (1112) that supports the inner box mounting plate so as to be spaced a certain distance from the floor surface of the outside or inside.

[0050] According to one embodiment, a plurality of through holes (1111a) are formed in the inner mounting plate (1111) so that air can pass through the entire surface.

[0051] Additionally, a foundation member (F) may be further provided at the bottom of the DAC reactor (1000) to fix and support the inner support (1110) and outer support (1210) by means of bolts (B), etc. Depending on the indoor or outdoor installation environment, the foundation member (F) may be a concrete structure or a housing containing heavy materials such as sand or water.

[0052] Therefore, if the user wishes to move the DAC reactor (1000), the foundation member (F) can also be moved together. However, in an outdoor environment, if the foundation member (F) is a concrete floor, the foundation member (F) cannot be moved. Therefore, after moving the DAC reactor (1000) excluding the foundation member, the inner support (1110) and outer support (1210) can be fixedly installed on the concrete floor to which they have been relocated.

[0053] Additionally, a cover bracket (1221) is provided on the top of the outer body (1220) so that an upper cover (1300) can be optionally fitted and seated thereon. Accordingly, the inner diameter of the upper cover (1300) can be fitted into the cover bracket (1221) to be detachably fixed.

[0054] In addition, a lighting and communication assembly (1400) is provided on the top of the upper cover (1300).

[0055] Referring to FIGS. 3 and 4, according to one embodiment, the lighting and communication assembly (1400) is equipped with a lighting light (1410), a CO2 sensor and communication module (1420), first and second solar power generation modules (1430-1, 1430-2), an LCD module (1450), etc. Accordingly, power produced by the first and second solar power generation modules (1430-1, 1430-2) supplies power to the lighting light (1410), the CO2 sensor and communication module (1420).

[0056] At this time, the CO2 sensor and communication module (1420) is each equipped with a first sensor and communication module (1420-1) for measuring the carbon dioxide concentration in the outside air and a second sensor and communication module (1420-2) for measuring the carbon dioxide concentration in the air discharged after carbon dioxide is adsorbed.

[0057] Therefore, as described above, the present invention allows air introduced through the air inlet hole (1200a) by natural convection without the application of a separate power source, and then discharged to the outside through the air outlet hole (1300a) after contacting the dry carbon dioxide absorbent (dry KLC) of the inner container (1100). Additionally, the lighting (1410), CO2 sensor, and communication module (1420-1, 1420-2) can be operated independently using the electrical energy produced by the first and second photovoltaic power generation modules (1430-1, 1430-2). Accordingly, the present invention has the advantage of being easy to move and place indoors or outdoors.

[0058] Meanwhile, the method for manufacturing a dry carbon dioxide absorbent, which is a component of the present invention, consists of the following steps.

[0059] Step (S100): Prepare materials for manufacturing a dry absorbent.

[0060] According to one embodiment, in step (S100), silicate mineral (powder), carbonate mineral (powder), water glass, basic alkali mixture (Applicant's trade name: 'KLC'), and other additives are prepared as materials for the dry absorbent according to the present invention.

[0061] The above silicate minerals may include wollastonite, olivine, and serpentine, and the above silicate minerals serve as an inorganic binder that prevents the dry absorbent from being damaged and maintains its shape during the calcination and recycling process of the dry absorbent described later.

[0062] In addition, according to one embodiment, the silicate mineral is reacted with an organic acid to extract a metallic cation.

[0063] For example, the above organic acid may include acetic acid, formic acid, citric acid, and lactic acid.

[0064] In addition, the above organic acid reacts with silicate minerals to extract metallic cations such as Ca2+, Mg2+, etc., as shown in <Reaction Scheme 1> below.

[0065] <Reaction Equation 1>

[0066] CaSiO3+ 2CH3COOH → Ca2+ + 2CH3COO- + H2O + SiO2

[0067] Here, the generated calcium ions and SiO2 act as inorganic binders that promote bonding with other substances during the calcination process.

[0068] The above carbonate minerals may include calcite (CaCO3), limestone (CaCO3), oyster shell (CaCO3), and magnesite (MgCO3). These minerals contain carbonate ions within their crystal structure and capture carbon dioxide from the atmosphere, and then perform the role of re-releasing carbon dioxide during the calcination process for the regeneration of the dry absorbent in the step (S600) described later.

[0069] The above mixture of water glass and basic alkali acts as an inorganic binder that enables the dry absorbent to maintain its shape even when continuous firing proceeds, just like the silicate minerals described above.

[0070] According to one embodiment, the basic alkali mixture ('KLC') comprises: one or more oxides selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3; one or more metals selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; a crystallized synthetic zeolite prepared from an alumina-based raw material, a silica-based raw material, and sodium hydroxide; and one or more liquid compositions selected from the group consisting of sodium tetraborate (Na2B4O7·10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3), potassium hydroxide (KOH), and hydrogen peroxide (H2O2).

[0071] That is, the above basic alkali mixture ('KLC') promotes the capture of carbon dioxide to form carbonate minerals as shown in <Reaction Scheme 2> below, and the carbonate minerals thus formed are firmly bound to the carbonate minerals of the dry absorbent, thereby stably capturing carbon dioxide in the dry absorbent.

[0072] <Reaction Equation 2>

[0073] KLC(CaO) + CO2 → CaCO3

[0074] The above additive may include biochar or lignocellulosic biomass; silica gel; potassium hydroxide (KOH) or sodium hydroxide (NaOH); and silicon dioxide (SiO2).

[0075] The role of each component included in the additive is as follows.

[0076] - Biochar, lignocellulosic biomass: Forms pores inside the dry absorbent as they disappear during the calcination process described later.

[0077] - Silica gel: Utilizes hygroscopic properties to increase the moisture content inside the dry absorbent.

[0078] - KOH, NaOH: Improves hygroscopicity and carbon dioxide absorption performance of dry absorbents

[0079] - SiO2: Strengthening of dry absorbents

[0080] Step (S200): Water is added to the dry absorbent material and mixed to form a dry absorbent paste.

[0081] According to one embodiment, the present step involves first adding silicate minerals and acetic acid to a mixer, and when the pH is 6 or higher, adding carbonate minerals, a basic alkali mixture ('KLC'), water glass, and additives to form a dry absorbent paste by mixing and reacting.

[0082] Step (S300): The dry absorbent paste is extruded to form dry absorbent pebbles of a certain size.

[0083] According to one embodiment, in this step, water is added to the dry absorbent paste to adjust the moisture content, and then extruded and molded through an extruder and a pill-making machine to form a dry absorbent pebble in the shape of a pill having a certain size.

[0084] Step (S400): The above dry absorbent pebbles are fired in a kiln.

[0085] According to one embodiment, the step (S400) comprises: (S410) a step of first drying the dry absorbent pebbles under certain conditions after introducing them into a kiln; and (S420) a step of secondarily firing the first dried dry absorbent pebbles under certain conditions.

[0086] In addition, according to one embodiment, step (S410) performs primary drying for 3 hours at a temperature of 120°C or lower, and step (S420) performs secondary firing for 3 hours at a temperature of 750°C to 900°C.

[0087] Step (S500): The above-mentioned calcined dry absorbent pebbles are hydrated to complete the manufacture of the dry absorbent.

[0088] This step involves adding an appropriate amount of moisture to the calcined dry absorbent pebbles to effectively capture carbon dioxide. Since the basic alkali mixture ('KLC') and the main component of the water glass contained in the dry absorbent pebbles are hygroscopic, they additionally absorb moisture from the atmosphere, allowing carbon dioxide to penetrate effectively into the interior of the dry absorbent.

[0089] According to one embodiment, the hydration process of step (S500) involves cooling the calcined dry absorbent pebbles to 50°C or lower and then placing them in an environment with a relative humidity of 40%RH to absorb moisture from the air.

[0090] Example: Preparation of dry absorbent pebbles for 'Carbon Tree'

[0091] For the manufacture of a dry absorbent according to the present invention, according to one embodiment, 41% by weight of wollastonite powder (silicate mineral), 41% by weight of limestone powder (carbonate mineral), 7% by weight of acetic acid (organic acid), 6% by weight of a basic alkali mixture ('KLC'), 5% by weight of water glass, and a small amount of additives were added to a mixer.

[0092] At this time, silicate minerals and acetic acid were first added to a mixer, and when the pH was 6 or higher, carbonate minerals, a basic alkali mixture ('KLC'), water glass, and additives were added and mixed to obtain a dry absorbent paste.

[0093] Next, water was added to the dry absorbent paste to adjust the moisture content, and then extruded and molded through an extruder and a pill-making machine to produce dry absorbent pebbles in the shape of pills with a diameter of 8 to 12 mm.

[0094] Next, the above dry absorbent pebbles were placed into a kiln, and after removing moisture by primary drying (120°C) for 3 hours, the carbon dioxide contained in the carbonate minerals was completely discharged through secondary calcination (750°C).

[0095] Finally, the dry absorbent pebble calcined as described above was hydrated by leaving it in an environment with a temperature of 40°C and a relative humidity of 40%RH (e.g., an aging chamber equipped with a hygrometer) for a certain period of time, thereby completing the production of a dry absorbent pebble as shown in Fig. 6.

[0096] Meanwhile, the method for regenerating a dry absorbent for carbon dioxide capture according to the present invention comprises the following steps according to one embodiment.

[0097] First, the dry absorbent for carbon dioxide capture according to the present invention is manufactured through the following steps: (S100) forming a dry absorbent powder as described above; (S200) adding water to the dry absorbent powder to form a dry absorbent paste; (S300) extruding the dry absorbent paste to form a dry absorbent pebble of a certain size; (S400) calcining the dry absorbent pebble in a calcination furnace; and (S500) hydrating the calcined dry absorbent pebble to complete the manufacture of the dry absorbent.

[0098] Next, a regeneration step (S600) of the dry absorbent is performed, and in detail, it may proceed through the following steps.

[0099] Step (S610): The dry carbon dioxide absorbent prepared through steps (S100) to (S500) is introduced into the DAC reactor of the present invention (also known as the 'Carbon Tree') to capture carbon dioxide from the atmosphere.

[0100] At this time, since the above basic alkali mixture ('KLC') contains NaOH, the carbon dioxide capture reaction rate is faster compared to CaO or Ca(OH)2; therefore, the actual carbon dioxide capture reaction equation performed in the above DAC reactor is as follows.

[0101] <Reaction Equation 3> 2NaOH + Ca(OH)2 + CO2 → Na2CO3 + Ca(OH)2

[0102] <Reaction Equation 4> Na2CO3 + Ca(OH)2 → CaCO3 + 2NaOH

[0103] Step (S620): After capturing carbon dioxide from the atmosphere using the above DAC reactor, if the carbon dioxide capture performance of the dry absorbent deteriorates, it is fed back into the calcination furnace to calcin and hydrate, thereby restoring the capture performance of the dry absorbent to its manufacturing state.

[0104] In the above calcination process, carbon dioxide can be separated as shown in the following reaction equation.

[0105] <Reaction Equation 5>

[0106] CaCO3 + Heat → CaO + CO2 (carbon dioxide separation)

[0107] According to one embodiment, carbon dioxide separated from the dry absorbent during the calcination process of step (S620) is recaptured using the basic alkali mixture of the present invention (Applicant's trade name: 'KLC') to produce a carbon dioxide reactant, and the carbon dioxide reactant can be utilized in the production of carbonate minerals including sodium carbonate or sodium bicarbonate.

[0108] For example, the carbon dioxide reactant may include sodium carbonate (Na2CO3) or sodium bicarbonate (NaHCO3).

[0109] The above carbon dioxide reactant can be produced by reacting a basic alkali mixture with carbon dioxide as shown in <Reaction Scheme 6> below.

[0110] <Reaction Equation 6>

[0111] 2NaOH + CO2 → Na2CO3 + H2O

[0112] Na2CO3 + H2O + CO2 → 2NaHCO3

[0113] Specifically, carbon dioxide is emitted from the above carbon dioxide reactant during the calcination process in a kiln or calciner, and carbon dioxide is re-emitted when the dry absorbent that has absorbed carbon dioxide is calcined.

[0114] That is, the above-mentioned kiln has a high temperature and a small internal volume, so pressure is naturally generated inside the kiln. Due to this pressure, carbon dioxide naturally escapes through the pipes connected to the kiln, and the present invention can use the carbon dioxide that escapes in this way as itself or utilize it as a raw material for other substances.

[0115] For example, the above-mentioned recaptured carbon dioxide can be used to produce carbon-neutral fuels such as e-SAF (Sustainable Aviation Fuel) or e-MeOH (e-methanol), or chemical raw materials such as DME and olefins. In this case, the said raw materials can be chemically synthesized by reacting the recaptured carbon dioxide with hydrogen.

[0116] Step (S630): The dry carbon dioxide absorbent regenerated in Step (S620) is reintroduced into the DAC reactor (1000) to perform carbon dioxide capture from the atmosphere again.

[0117] Test Example: Performance measurement of dry carbon dioxide absorbent for 'Carbon Tree'

[0118] - Carbon dioxide capture agent (dry absorbent): Use 10kg of dry KLC

[0119] - Replacement cycle: 1 month

[0120] - Insertion Method: Insert into the illuminated Zero C 1K (Carbon Tree) inner cartridge

[0121] - Verification Method: Comparison of carbon dioxide levels before and after capture via TGA analysis one month after capture, and monitoring of real-time carbon dioxide concentration changes through a carbon dioxide sensor.

[0122] - Verification Result: Carbon dioxide sequestration performance of 1.075 kg was confirmed through XRD and TGA data analysis.

[0123] 1) XRD Data: Confirmed that the CaCO3 peak increased before and after the operation of the illumination-type Zero C (i.e., increased CaCO3 production).

[0124] 2) TGA Data: The amount of isolated carbon dioxide was confirmed through TGA (Thermogravimetric Analysis) before and after the operation of the illuminated Zero C.

[0125] 3) Calculation of the amount of CO2 isolated through an increase in CaCO3 content

[0126] Increase in CaCO3 = 39.93% - 15.5% = 24.43%

[0127] CO2 content = 24.45% × 44 / 100 (molecular weight) = 10.75% (i.e., 10.75% of CO2 was sequestered from the total sample)

[0128] Therefore, it was confirmed that the total input amount of dry absorbent pebbles = 10kg × 10.75% = 1.075kg of CO2 was sequestered.

[0129] Figure 5 is a graph of the carbon dioxide absorption and regeneration cycle operation according to the present invention, through which it can be seen that the direct air capture device of the present invention efficiently performs the carbon dioxide absorption and regeneration process.

[0130] At this time, the graph in Figure 5 above represents the regeneration process of the carbon dioxide absorbent using TGA (thermogravimetric analysis), and the mass loss that occurs in the dry carbon dioxide absorbent regeneration section at 550~850℃ represents the amount of CO2 captured.

[0131] Accordingly, by utilizing the above-described configuration, the present invention can achieve the world's highest level of carbon dioxide adsorption performance of 2.4 mmol / g or more by using a dry carbon dioxide absorbent, and by desorbing carbon dioxide at a low temperature, there is no degradation of the absorbent, and the energy required is low, thereby improving economic efficiency, while at the same time, no environmentally harmful substances are generated, thus achieving an eco-friendly effect.

[0132] In addition, by recycling the carbon dioxide adsorbed through the present invention into the production of useful resources, it is possible to achieve the effect of contributing to overcoming the climate crisis related to global warming.

[0133] Furthermore, the present invention is not limited solely to the embodiment described above. Since the same effect can be achieved even when the detailed configuration, number, or arrangement structure of the device is changed, it is hereby specified that those skilled in the art can add, delete, or modify various configurations within the scope of the technical concept of the present invention.

[0134] The present invention can be widely used in the field of direct air capture devices using dry carbon dioxide absorbents.

Claims

1. A dry carbon dioxide absorbent manufactured in the form of a pebble of a certain size; and a Direct Air Capture (DAC) reactor that replaceably accommodates the dry carbon dioxide absorbent within a mesh structure and absorbs and captures carbon dioxide from the air by bringing the dry carbon dioxide absorbent into contact with air; comprising a direct air capture device using a dry carbon dioxide absorbent.

2. In Paragraph 1, The above dry carbon dioxide absorbent is, (S100) Step of preparing dry absorbent material; (S200) A step of mixing and reacting the above dry absorbent materials to form a dry absorbent paste; (S300) A step of extruding and molding the above dry absorbent paste to form a dry absorbent pebble of a certain size; (S400) A step of firing the above dry absorbent pebbles in a kiln; (S500) A direct air capture device using a dry carbon dioxide absorbent manufactured by the step of completing the manufacture of a dry absorbent by hydrating the above-mentioned calcined dry absorbent pebbles.

3. In Paragraph 2, The dry absorbent powder of the above step (S100) is, A direct air capture device using a dry carbon dioxide absorbent characterized by being formed by mixing silicate minerals, carbonate minerals, water glass, a basic alkali mixture, and additives.

4. In Paragraph 3, The above basic alkali mixture is, One or more oxides selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3; One or more metals selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; Crystallized synthetic zeolite prepared from alumina-based raw materials, silica-based raw materials, and sodium hydroxide; and, A direct air collection device using a dry carbon dioxide absorbent comprising one or more liquid compositions selected from the group consisting of sodium tetraborate (Na2B4O7·10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3), potassium hydroxide (KOH), and hydrogen peroxide (H2O2).

5. In Paragraph 3, The above additive is, A direct air capture device using a dry carbon dioxide absorbent comprising at least one of biochar, lignocellulosic biomass, silica gel, potassium hydroxide (KOH), sodium hydroxide (NaOH), and silicon dioxide (SiO2).

6. In Paragraph 1, The above DAC reactor is, A housing having a mesh-like structural shape and capable of replacingably accommodating the dry carbon dioxide absorbent; and, A direct air collection device using a dry carbon dioxide absorbent, comprising: an outer casing that surrounds and protects the periphery of the inner casing and provides an air passage so that air introduced from one side can come into contact with the dry carbon dioxide absorbent contained in the inner casing and then be discharged to the other side.

7. In Paragraph 6, The above inner box is, An inner box support installed at a certain distance from the floor surface of an outdoor or indoor space; and A direct air collection device using a dry carbon dioxide absorbent, comprising: a cylindrical or polygonal tube body containing a dry carbon dioxide absorbent, having a plurality of through holes formed on the entire circumference of the tube body, and an inner box body selectively seated on the inner box support.

8. In Paragraph 6, The above enclosure is, An outer casing support provided around the circumference of the inner casing support to surround the inner casing support; and, A direct air collection device using a dry carbon dioxide absorbent, comprising: an outer casing body integrally formed on the outer casing support and having a plurality of through holes formed in at least a part of a cylindrical or polygonal tube so that air can be introduced or discharged.

9. In Paragraph 6, A direct air collection device using a dry carbon dioxide absorbent, characterized by the fact that the top of the above-mentioned enclosure is opened and an upper cover is further provided on the open top of the above-mentioned enclosure to selectively open and close the open top of the above-mentioned enclosure.

10. In Paragraph 8, A direct air collection device using a dry carbon dioxide absorbent, wherein the bottom of the above-mentioned enclosure is further equipped with a lower protective cover to completely surround and protect the enclosure support.

11. In Paragraph 7, The above inner box support is, A housing mounting plate that supports the housing body on which it is placed; and, A direct air collection device using a dry carbon dioxide absorbent, comprising: a leg portion that supports the above-mentioned inner mounting plate so as to be spaced a certain distance from the floor surface of the outside or inside.

12. In Paragraph 8, A direct air collection device using a dry carbon dioxide absorbent, wherein a cover bracket is further provided on the top of the above-mentioned outer body so that an upper cover can be optionally fitted and seated thereon.

13. In Paragraph 9, A direct air capture device using a dry carbon dioxide absorbent, wherein the upper cover is further equipped with a lighting light, a CO2 sensor, and a communication module.

14. In Paragraph 9, A direct air capture device using a dry carbon dioxide absorbent, characterized in that the upper cover is further equipped with a solar power generation module to supply power to the lighting, CO2 sensor, and communication module.

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