Coulomb force-driven CO2 release by electromagnetic radiation in amine-containing solid adsorbents

Abstract

A method for selectively releasing CO2 from a CO2-supported solid adsorbent includes applying electromagnetic radiation having an intensity of 0.7 watts / square centimeter or more and a frequency of about 400 terahertz to about 70 kilohertz to the CO2-supported solid adsorbent to release CO2, wherein the CO2-supported solid adsorbent includes chemiadsorbed CO2, phytoadsorbed CO2, or a combination thereof, and a solid adsorbent, the solid adsorbent containing at least one amine compound.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims the interests of U.S. Patent Application No. 18 / 316788, filed on 12 May 2023, which is incorporated herein by reference in its entirety. [Background technology]

[0002] This disclosure relates to a method for releasing carbon dioxide from a solid adsorbent, and in particular to a method for releasing carbon dioxide in an energy-efficient manner.

[0003] Carbon dioxide adsorption and separation technology is a cyclical process. After the adsorbent is saturated with CO2, a desorption process, or regeneration, is required. The desorption process is essential for the reuse of the solid adsorbent and for the recovery and storage of CO2. Desorption is also a crucial part of the recovery chain and significantly impacts the overall efficiency of the process.

[0004] Amine-functionalized solid adsorbents are widely used in cyclic adsorption processes for carbon recovery. CO2 recovery from these materials can be achieved through pressure swings, temperature swings, vacuum swings, and / or combinations of these condition changes. In direct air capture (DAC) of CO2 from the atmosphere, strong CO2-adsorbent interactions are necessary to selectively remove CO2 from the air, in preference to other components. Therefore, the application of state-of-the-art processes and solid adsorbent materials for DAC requires thermal swings to provide the majority of the energy needed to release CO2 from the material.

[0005] One of the biggest obstacles to a commercially viable DAC process is the cost of energy-intensive regeneration cycles. Conventional thermal swing approaches require heating both the solid materials used to capture CO2 and the devices within the system (cartridges, piping, etc.), leading to large heat sinks and parasitic energy losses. Furthermore, heating all of these components takes time, increasing cycle times and reducing system productivity.

[0006] Furthermore, many adsorbents are insulating, and therefore heat distribution can be a problem. Consequently, there is a continued need for effective methods to release carbon dioxide from solid adsorbents in an energy-efficient manner. [Overview of the project]

[0007] A method for selectively releasing CO2 from a CO2-supported solid adsorbent includes applying electromagnetic radiation having an intensity of 0.7 watts / cm² or more and a frequency of about 400 terahertz to about 70 kilohertz to the CO2-supported solid adsorbent to release CO2, wherein the CO2-supported solid adsorbent includes a solid adsorbent and chemically adsorbed CO2, physically adsorbed CO2, or a combination thereof, and the solid adsorbent includes at least one amine compound.

[0008] A method for removing carbon dioxide from a gaseous environment or exhaust gas flow includes: exposing a solid adsorbent to a gaseous environment or exhaust gas flow; removing CO2 from the gaseous environment or exhaust gas flow to form a CO2-supported solid adsorbent; and applying electromagnetic radiation having an intensity of 0.7 watts / cm² or more and a frequency of about 400 terahertz to about 70 kilohertz to the CO2-supported solid adsorbent to release CO2 and regenerate the solid adsorbent, wherein the CO2-supported solid adsorbent includes a solid adsorbent and chemically adsorbed CO2, physically adsorbed CO2, or a combination thereof, and the solid adsorbent includes at least one amine compound. [Brief explanation of the drawing]

[0009] The drawings are provided with illustrative and non-limiting descriptions. [Figure 1] Examples of possible compounds that may be present in CO2-supported solid adsorbents are shown below. [Figure 2A] This graph shows the infrared (IR) intensity against wavenumber (reciprocal of centimeter, cm⁻¹), illustrating the Fourier transform infrared (FTIR) characteristics of a CO₂-supported solid adsorbent before and after heating under nitrogen at 100°C in a DRIFT cell. The IR intensity was measured by an IR reflection experiment, and the signal intensity is proportional to the IR absorbance. [Figure 2B] This graph shows the infrared (IR) intensity against wavenumber (reciprocal of centimeter, cm⁻¹), illustrating the Fourier transform infrared (FTIR) characteristics of a CO₂-supported solid adsorbent before and after heating under nitrogen at 100°C in a DRIFT cell. The IR intensity was measured by an IR reflection experiment, and the signal intensity is proportional to the IR absorbance. [Figure 3A] This graph shows the IR absorbance (optical density (OD)) against wavenumber (cm-1), illustrating the FTIR characteristics of a CO2-supported solid adsorbent before and after gradual heating from 28°C to 150°C in a temperature cell. [Figure 3B] This graph shows the IR absorbance (optical density (OD)) against wavenumber (cm-1), illustrating the FTIR characteristics of a CO2-supported solid adsorbent before and after gradual heating from 28°C to 150°C in a temperature cell. [Figure 3C] This graph shows the change in IR absorbance with respect to adsorbent temperature (°C), illustrating the temperature dependence of the IR signal change when a solid adsorbent transitions from a state bound to CO2 to a state where CO2 is released. [Figure 3D] This graph shows CO2 release as a function of adsorbent temperature (°C). It is a graph obtained by integrating the IR signal of CO2 at 2100-2600 cm-1 in the gas phase and plotting it as a function of adsorbent temperature. [Figure 4A]This graph shows the IR absorbance of a CO2-supported solid adsorbent against wavenumber (cm⁻¹) before (black line) and after (gray line) continuous wave (cw) IR irradiation at a power output of 7 milliwatts (mW) for 50 hours. The wavenumber range of the irradiation light was 2670–2350 cm⁻¹ (full width at half maximum, FWHM) as set by the IR bandpass filter. The total energy of the sample investigated was 0.14 joules, and the light intensity at the sample was 0.005 watts / cm². The intensity in the frequency range above 300 GHz is defined as the irradiation power across the irradiation spot size. [Figure 4B] An increase in CO2 IR absorbance was observed in the wavenumber range of 2400–2300 cm⁻¹, and the IR absorbance of CO2 was measured for CO2 emitted from the investigated samples. [Figure 5A] This graph shows the IR absorbance against wavenumber (cm⁻¹) of a CO₂-supported solid adsorbent before (black line) and after (gray line) 5 minutes of irradiation with a short IR pulse of approximately 300 femtoseconds (fs) with a repetition rate of 1 kilohertz (KHz), at an excitation wavenumber of 2650-2400 cm⁻¹ (FWHM) and an output power of 2 mW. The total irradiation energy was 0.0007 joules, and the intensity in the sample was 51 megawatts / cm² (MW / cm²). [Figure 5B] This shows the difference in IR absorbance of CO2 emitted in the wavenumber range of 2300-2400 cm⁻¹ during irradiation as described in Figure 5A. [Figure 5C] This graph shows the IR absorbance of a CO2-supported solid adsorbent before (black line) and after (gray line) irradiation with a short near-infrared (NIR) pulse of approximately 80 fs with a repetition rate of 1 kHz, at 800 nm (12500 cm⁻¹) and an output of 1.97 W for 2 minutes, against wavenumber (cm⁻¹). The total energy was 0.24 joules, and the intensity at the sample was 31 gigawatts / cm² (GW / cm²). [Figure 6]This graph shows the generation of CO2 from a CO2-supported solid adsorbent when excited with a 2.45 gigahertz (GHz) microwave energy under nitrogen gas. The solid line represents the ratio of the volume of released CO2 to the volume of nitrogen gas as a percentage of the irradiation time (seconds, sec), and the dashed line represents the CO2 mass spectrum as a percentage of the irradiation time (seconds). [Figure 7A] The CO2 emission profile under conductive thermal heating using a nitrogen stream is shown. The solid line represents the amount of CO2 released (parts per million, ppm) as a percentage of heating time (minutes, min), and the dashed line represents the heating temperature (°C) as a percentage of heating time (minutes). [Figure 7B] This graph shows the CO2 emission profile when 2.45 GHz microwave energy is applied to a CO2-supported solid adsorbent, representing the amount of CO2 emitted (ppm) as a percentage of irradiation time (minutes, min). [Figure 8] The CO2 emission profiles under two different microwave power levels (700 watts (W) and 1000 watts (W)) are shown, illustrating the dramatic difference in CO2 emission due to small temperature differences (circles). The solid and dashed lines represent the regeneration flow rate (milliliters per minute, mL / min) as a function of irradiation time (minutes) under microwave power levels of 700 W and 1000 W, respectively. The black and white circles represent the local temperature (°C) measured on the solid adsorbent as a function of irradiation time (minutes) under microwave irradiation power levels of 700 W and 1000 W, respectively. The microwave irradiation intensity in the frequency range below 300 GHz was defined as the irradiation power as the square of the wavelength, and since the wavelength was 12.24 cm (size of the sample bed), the intensities used were 4.67 W / cm² (for 700 W output) and 6.67 W / cm² (for 1000 W output). [Modes for carrying out the invention]

[0010] A detailed description of one or more embodiments is provided herein as an example, not an limitation.

[0011] Until now, the release of carbon dioxide from solid adsorbents has relied on conventional heating mechanisms by convection and conduction. The method disclosed herein is non-thermal, and the CO2 release is a result of incident light and / or an electromagnetic field. In particular, the inventors have found that single-photon absorption of an electromagnetic field can directly result in CO2 release. The absorbed photon induces an increase in the vibrational amplitude of bonds in the solid adsorbent, which leads to the release of CO2. As used herein, single-photon absorption is defined as the linear dependence of the adsorbent's effect on the number or intensity of the irradiated photons. Furthermore, an electric field can act on charged groups in a CO2-supported solid adsorbent, causing them to release CO2. The effect of the electric field on the charged groups to release CO2 is independent of the frequency of light. Since it is a direct electric field effect, the CO2 release is non-thermal.

[0012] Compared to thermal swings, the non-thermal methods described herein reduce the energy load required to generate a thermal swing of a solid adsorbent for CO2 capture. For example, the method can increase the amount and / or rate of CO2 release with the same energy consumption. CO2 release can also be at least 1%, 2%, 5%, 10%, or 30% more efficient compared to conventional heating. This provides a pathway for energy savings throughout the process.

[0013] Using non-thermal methods as described herein also requires less process equipment such as piping and ducts, as it requires less equipment to induce electromagnetic radiation compared to heat transfer fluids such as water (conduction) or CO2 (convection).

[0014] A method for selectively releasing CO2 from a CO2-supported solid adsorbent includes applying electromagnetic radiation to the CO2-supported solid adsorbent to release chemisorbed carbon dioxide, phytosorbed carbon dioxide, or a combination thereof.

[0015] Electromagnetic radiation has a frequency of from about 70 kHz to about 400 terahertz (THz), for example, from about 0.005 gigahertz (GHz) to about 400 THz, from about 300 GHz to about 105 THz, or from about 0.3 GHz to 300 GHz, or from about 0.01 GHz to about 2.54 GHz, or from about 0.07 MHz to about 120 THz, or from about 0.07 MHz to about 1 THz, or from about 0.07 MHz to about 95 THz, or from about 0.1 GHz to about 120 THz, or from about 0.01 GHz to about 100 GHz, or from 12 THz (400 cm -1 ) to 120 THz (4000 cm -1 ), or from about 1 THz to 12 THz, or from about 0.2 THz (6.67 cm -1 ) to 5 THz (166 cm -1 ), or from about 17 THz to about 102 THz (3400 cm -1 ), or from about 62.8 THz to about 105 THz, or from 29.9 THz (997 cm -1 ) to about 54 THz (1800 cm -1 ).

[0016] Electromagnetic radiation can have a wave number of from about 400 cm -1 to about 4000 cm -1 , from about 1800 cm -1 to about 3000 cm -1 , from about 1800 cm -1 to about 2800 cm -1 , from about 2200 cm -1 to about 2800 cm -1 , or from about 2350 cm -1 to about 2670 cm -1 .

[0017] CO2 can be released from a solid adsorbent using electromagnetic radiation having an intensity of 0.005 W / cm 2 or more. For an efficient and fast process, the intensity of the electromagnetic radiation must be higher. The electromagnetic radiation has an intensity of about 0.7 W / cm 2 or more, specifically from about 0.7 W / cm 2 to about 500 GW / cm 2 . In the case of continuous radiation, the electromagnetic radiation is from about 0.7 W / cm 2 2]]to about 1500 W / cm2 It has an intensity of approximately 5 W / cm² in the case of pulsed radiation. 2 ~About 500GW / cm 2 It can have that strength.

[0018] In the case of continuous irradiation, the intensity is approximately 0.7 W / cm² in the frequency range of approximately 400 THz to approximately 12 THz. 2 Above, or approximately 1.4 W / cm² 2 That's all. The upper limit is approximately 150 kW / cm². 2 In the case of continuous irradiation in the frequency range of approximately 12 THz to approximately 300 GHz, the intensity is approximately 0.7 W / cm². 2 Above or approximately 1 W / cm² 2 Above, or approximately 1.5 W / cm² 2 Above, or approximately 15 W / cm² 2 Above, or approximately 150 W / cm² 2 Above, or approximately 1500 W / cm² 2 That's all. The upper limit is approximately 150 kW / cm². 2 In the case of continuous irradiation in the frequency range of approximately 300 GHz to approximately 0.07 MHz, the intensity is approximately 0.7 W / cm². 2 Above or approximately 1 W / cm² 2 Above, or approximately 2 W / cm² 2 Above, or approximately 4 W / cm² 2 Above, or approximately 6 W / cm² 2 That's all. The upper limit is approximately 150 kW / cm². 2 That is the case.

[0019] In the case of pulsed irradiation, the intensity is approximately 0.005 kW / cm² in the frequency range of approximately 400 THz to approximately 12 THz. 2 Above, or approximately 0.5 kW / cm² 2 Above, or approximately 50 kW / cm² 2 Above or approximately 5 MW / cm² 2 Above or approximately 50 MW / cm² 2 That concludes the explanation. In the case of pulsed irradiation in the frequency range of approximately 12 THz to approximately 300 GHz, the intensity is approximately 0.005 kW / cm². 2 Above, or approximately 0.5 kW / cm² 2 Above, or approximately 50 kW / cm² 2 Above or approximately 5 MW / cm²2 Above or approximately 50 MW / cm² 2 That concludes the explanation. In the case of pulse irradiation in the frequency range of approximately 300 GHz to approximately 0.07 MHz, the intensity is approximately 1 W / cm². 2 Above, or approximately 2 W / cm² 2 Above, or approximately 4 W / cm² 2 Above, or approximately 6 W / cm² 2 Above, or approximately 8 W / cm² 2 Above, or approximately 10 W / cm² 2 That concludes the explanation. The upper limit of pulse irradiation intensity is approximately 500 GW / cm². 2 That is the case.

[0020] The inventors have found that increasing the intensity of electromagnetic radiation at the same energy and / or temperature level increases CO2 emissions in terms of the amount of CO2 emitted, the rate of CO2 emission, or a combination thereof. This refers to a novel process called Coulomb force-driven CO2 emission.

[0021] Advantageously, electromagnetic radiation can have a single-photon energy lower than the binding energy between carbon dioxide and the solid adsorbent. For example, electromagnetic radiation can have a single-photon energy at least about 100 cm⁻¹ lower than the binding energy between carbon dioxide and the solid adsorbent. -1 Low, at least about 200cm -1 Low, or at least about 300 cm -1 Low, or at least about 600 cm -1 It can have a low single-photon energy.

[0022] Electromagnetic radiation can be continuous radiation, pulsed radiation, non-coherent radiation, or coherent radiation. The pulse length of non-coherent or coherent pulsed radiation can be about 3 fs to about 1 second (s), or about 10 fs to about 1 s, or about 50 fs to about 500 milliseconds (ms), or about 100 fs to about 500 microseconds (μs), or about 0.5 picoseconds (ps) to about 500 nanoseconds (ns), or about 1 ps to about 10 ns, or about 3 fs to about 500 ns, or about 10 ps to about 1 s, or about 50 ps to about 500 ps, ​​or about 1 ns to about 1 μs, or about 1 ms to about 1 s.

[0023] Electromagnetic radiation pulses can be generated by non-coherent light sources. Such non-coherent light sources include, for example, standard infrared lamps, Glover lamps, gas discharge lamps, pulsed lasers, magnetrons, and synchrotron radiation sources such as the Shanghai Synchrotron Radiation Facility (SSRF) generator. Coherent light sources can include continuously emitting lasers or continuous-wave lasers. In the case of continuously emitting lasers (also called continuous-wave lasers), electromagnetic light pulses can be generated by a subsequently placed shutter or equivalent element. Any pulse duration longer than one second is defined as continuous emission.

[0024] The irradiation time can vary from a few femtoseconds to a few seconds or even a few hours, depending on the specific solid adsorbent used. Irradiation can be carried out at room temperature or in a temperature range of approximately 213K to 423K.

[0025] The solid adsorbent comprises an amine compound (also called "amine"), and may further comprise a metal moiety and, optionally, an organic linker. The amine, metal moiety, and organic linker may be the same as those described herein in the context of amine-functionalized metal-organic frameworks (MOFs).

[0026] Solid adsorbents can have pore diameters of about 0.4 nanometers (nm) to about 10 μm, preferably about 0.5 nm to about 2 μm, or about 0.5 nm to 0.1 μm, or about 0.4 nm to about 50 nm, and porosity of about 1% to about 95%, preferably about 15% to about 45% or about 25% to about 40%, more preferably about 30% to about 35%, or at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, or at least about 45%. As used herein, pore diameter refers to the maximum dimension of the pore. In one embodiment, the pore diameter of pores in the solid adsorbent may be in the range of about 5 to about 20 Å, while the pore wall region may be approximately the thickness of a single molecule. The internal specific surface area of ​​the solid adsorbent may be up to about 10,000 square meters / gram (m²). 2 ( / g) more than, for example, about 1m 2 / g~approx. 10,000m 2 / g, preferably about 100m 2 / g~10,000m 2 / g, comfortably for approximately 1,000m 2 / g~approx. 10,000m 2 It could be / g

[0027] Solid adsorbents are not thermally conductive and may have a thermal conductivity of less than approximately 0.1 watts per meter Kelvin (W / mK), less than approximately 0.05 W / mK, less than approximately 0.01 W / mK, or less than approximately 0.005 W / mK.

[0028] In one embodiment, the solid adsorbent is an amine-functionalized MOF. The MOF includes an inorganic node connected by an organic linker. The inorganic node includes a metallic moiety, which may be at least one ion from Mg, Ca, Ba, Al, Sc, Zr, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ti, Cd, or Eu, preferably at least one ion from Mg, Mn, Zn, or Ni. The organic linker may include at least one from carboxylate, triazolate, or imidazolate, preferably a carboxylate. Examples of organic linkers include 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylate, 2,5-dihydroxybenzene-1,4-dicarboxylate, 4,6-dihydroxybenzene-1,3-dicarboxylate, benzene-1,4-dicarboxylate, benzene-1,3,5-tricarboxylate, 3,3',4,4'-benzophenone-tetracarboxylate, benzene-1,2,4,5-tetracarboxylate, trans-1,4-cyclohexanedicarboxylate, 1H,7H-[1,4]dioxyno[2,3-F:5,6-F']bisbenzotriazolate, 1, Examples include, but are not limited to, 5-dihydrobenzo[1,2-d:4,5-d']bis([1,2,3]triazolate, 3,5-dimethyl-1H-pyrazole-4-carboxylate, 5-(pyridine-3-yl)benzene-1,3-dicarboxylate, 1,3,5-tri(1H-tetrazole-5-yl)benzene, 2-methylimidazolate, 2-ethylimidazolate, and 1-benzyl-1H-imidazolate. Other suitable known organic linkers may also be used. Preferably, the organic linker includes 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylate.

[0029] Examples of MOFs include, but are not limited to, MOF-74, MOF-274, HKUST-1, MIL-100, MIL-101, MOF-525, MOF-2, MOF-505, and UiO-66. Further MOFs include, but are not limited to, those described in Chem.Soc.Rev.2020,49,2751-2798. A preferred MOF is Mg2(dobpdc), where the inorganic node contains a Mg ion and the organic linker contains 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylate(dobpdc).

[0030] Amines can be monoamines; diamines such as primary / primary diamines, primary / secondary diamines, primary / tertiary diamines, and secondary / secondary diamines; polyamines such as triamines, tetramines, and aminopolymers; or bifunctional amines.

[0031] Monoamines may be monoalkylamines, dialkylamines, trialkylamines, monoarylamines, diarylamines, triarylamines, and mixed alkyl-arylamines. Examples of monoamines include, but are not limited to, aniline, n-butylamine, n-pentylamine, n-hexylamine, diphenylamine, and triethylamine.

[0032] Examples of diamines include, but are not limited to, ethylenediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-diaminopentane, 2-methylpropane-1,2-diamine, N-ethylethylenediamine, N-isopropylethylenediamine, N-butylethylenediamine, N-pentylethylenediamine, N-hexylethylenediamine, N,N-dimethylethane-1,2-diamine, N,N-diethylethylenediamine, N,N-diisopropylethylenediamine, N,N-dimethylpropylenediamine, N,N'-dimethylethane-1,2-diamine, 2-(aminomethyl)piperidine, and N,N-diethyl-N-methylethylenediamine.

[0033] Suitable polyamines include, but are not limited to, bis(3-aminopropyl)amine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, tetraethylenepentaamine, polyethyleneimine, and polypropyleneimine. Preferably, the functionalizing agent comprises primary / secondary diamines as disclosed herein.

[0034] As used herein, a difunctional amine refers to an amine having an additional functional group other than an amino group. Examples of difunctional amines include, but are not limited to, amino alcohols (also known as alkanolamines).

[0035] The solid adsorbent may be in the form of pellets. The pellets may have a particle size of about 0.1 mm to about 10 mm, preferably about 0.3 mm to about 3 mm, and more preferably about 0.7 mm to about 1.5 mm. The solid adsorbent may also exist in the form of a standalone film, a coating on another substrate, or a self-supporting monolith. The film or coating may have a thickness of about 0.01 mm to about 10 mm, preferably about 0.1 mm to about 1.0 mm.

[0036] Solid adsorbents can be converted into CO2-supported solid adsorbents when exposed to carbon dioxide. In CO2-supported solid adsorbents, carbon dioxide is chemically and / or physically adsorbed onto the solid adsorbent. CO2-supported solid adsorbents may also contain co-adsorbed water.

[0037] CO2-supported solid adsorbents are stable at room temperature. In one embodiment, when a CO2-supported solid adsorbent is stored for one week at 20°C and atmospheric pressure without exposure to electromagnetic radiation, as disclosed herein, less than 30%, less than 10%, less than 3%, less than 2%, or less than 1% of the carbon dioxide in the CO2-supported solid adsorbent is released, and the percentage of released CO2 is a volume percentage based on the total volume of CO2 supported on the solid adsorbent.

[0038] CO2-supported solid adsorbents contain charged or partially charged groups. Because Coulomb forces act on the supported solid adsorbent to displace carbon dioxide, the CO2-supported solid adsorbent may have a partial charge of about 0.1 to less than about 1, preferably about 0.2 to less than about 1, or about 0.5 to about 1. The partial charge is the net charge at an atom within its van der Waals radius.

[0039] In a CO2-supported solid adsorbent, CO2 can react with an amine and optionally with water to form at least one of carbonate ions, bicarbonate ions, ammonium ions, carbamates, or carbamic acid. Figure 1 shows the formation of carbamic acid (a), ammonium carbamate (b), ammonium bicarbonate (c), and ammonium carbonate (d), where R1 and R2 are independently organic groups having at least one heteroatom such as H, or N or O, except that both R1 and R2 are not H. The CO2-supported solid adsorbent may contain at least one of (a), (b), (c), or (d).

[0040] In CO2-supported solid adsorbents, ammonium carbamate has a capacity of approximately 3400 cm³. -1 , about 2800~1800cm -1 , about 1650cm -1 , and approximately 1350cm -1 In this case, it may have a characteristic IR band or marker IR band. Approximately 1800-2800 cm -1 The wide absorption zone is 2500cm -1 It can be described as a broad band in the vicinity.

[0041] Approximately 1800cm -1 ~Approx. 3200cm -1 , or approximately 1800cm -1 ~Approx. 2800cm -1When electromagnetic radiation of a certain wavelength is applied, absorption occurs, and some of the photons are absorbed by vibrational bands that reflect CO2 adsorption. These vibrational bands that reflect CO2 adsorption can be called carbamate groups. The absorption of photons leads to the activation of the absorbed carbamate vibrations. This activation can lead to an increase in the vibrational amplitude. The carbamate groups are partially charged. The increase in amplitude induces a periodic change in the electric field, which in turn induces a Coulomb force that drives CO2 emission. Otherwise, the absorbed energy is redistributed through vibrational energy relaxation channels. In one embodiment, carbon dioxide is selectively emitted by the energy generated by vibrational excitation via a single-photon process.

[0042] The activated vibrations can relax via lower-frequency vibrations on a picosecond timescale until thermal equilibrium is reached. The temperature may rise slightly on a nanosecond timescale. The final temperature rise can be minimal because the photon energy must be redistributed across all degrees of freedom of the light-absorbing material (3N-6 vibrations, where N is the number of atoms). In one embodiment, the temperature difference of the solid adsorbent before and after the selective release of CO2 is less than about 3°C, or less than about 5°C, or less than about 10°C, or less than about 30°C, or less than about 40°C.

[0043] Selective CO2 release can be used in DAC or other applications. A method for removing carbon dioxide from a gaseous environment or exhaust gas flow involves exposing the solid adsorbent described herein to a gaseous environment or exhaust gas flow, removing at least a portion of the carbon dioxide from the gaseous environment or exhaust gas flow to form a CO2-supported solid adsorbent, and 0.7 W / cm² 2 Continuous electromagnetic radiation with an intensity of 1 W / cm² or more. 2 The method includes applying pulsed electromagnetic radiation having the above intensity and a frequency of approximately 400 THz to approximately 70 kHz to a CO2-supported solid adsorbent to release CO2 and regenerate the solid adsorbent. If desired, a vacuum, an inert purge gas, or a combination thereof may be applied when the solid adsorbent is regenerated.

[0044] This method is further illustrated by the figures. Referring to Figures 2A and 2B, an amine-functionalized MOF was exposed to 2,000 ppm of dry CO2 to form a CO2-supported solid adsorbent. The IR spectra of the CO2-supported solid adsorbent are shown in Figures 2A and 2B (black line). The spectra are at 3400 cm⁻¹. -1 , 2800~1800cm -1 , 1650cm -1 , and 1350cm -1 These IR bands are characteristic of the amine-functionalized solid adsorbent, indicating that CO2 was adsorbed on the amine-functionalized solid adsorbent in the form of ammonium carbamate.

[0045] The IR spectrum remains unchanged at room temperature, indicating that the CO2-supported solid adsorbent is stable at room temperature and that carbon dioxide will not be released unless energy is applied to the supporting solid adsorbent. In fact, unless some form of energy is introduced to overcome the binding energy that binds CO2 to the solid adsorbent, CO2 can be permanently bound to the solid adsorbent. The binding energy of CO2 supported on an amine-functionalized solid adsorbent is approximately 70 kJ / mol or 5850 cm⁻¹. -1 It was determined that this is the case. (See RLSiegelmann et al., J.Am.Chem.Soc.2019, 141, 13171~13186.)

[0046] When the CO2-supported solid adsorbent is heated to 100°C, changes in the IR spectrum are observed, as shown in Figures 2A and 2B. All characteristic IR bands attributable to the ammonium carbamate pair disappear or change as the temperature rises, as indicated by the arrows, indicating complete cleavage of the carbamate species bound to the amine-functionalized solid adsorbent.

[0047] After cooling the solid adsorbent to room temperature, the initial spectrum (dark black line) can be recovered by exposing the solid adsorbent to CO2 gas. This result indicates that CO2 adsorption is reversible.

[0048] The release of CO2 due to thermal energy or temperature rise is further shown by the changes in the IR marker band and the CO2 band in FIGS. 3A to 3D. FIGS. 3A and 3B show the FTIR characterization of a CO2-supported solid adsorbent (amine-functionalized MOF) before and after being gradually heated from 28 °C to 150 °C in a temperature cell. Again, all characteristic IR bands (i.e., 3400 cm -1 , 2800 - 1800 cm -1 , 1650 cm -1 , and 1350 cm -1 ) due to the ammonium carbamate pairs in the CO2-supported solid adsorbent disappear or change as the temperature rises, indicating complete cleavage of the carbamate species bound to the amine-functionalized solid adsorbent.

[0049] FIG. 3C shows the temperature dependence of the IR signal change when the solid adsorbent transitions from the state of being bound to CO2 to the state of releasing CO2. Without gas exchange conditions, there is only one transition of heat-induced CO2 release with a peak around 70 - 80 °C. FIG. 3D shows the release of CO2 as a function of the solid adsorbent temperature, and the free CO2 gas concentration increases linearly in the sample cell and becomes constant after exceeding 100 °C.

[0050] Instead of heating, electromagnetic radiation also induces CO2 release, as shown by the changes in the IR marker band and the CO2 band. This method is non-thermal and energy-efficient.

[0051] To demonstrate the release of CO2 during IR irradiation as described herein, an IR globar lamp (2670 - 2350 cm -1A CO2-supported solid adsorbent (amine-functionalized MOF) was irradiated for 50 hours using (FWHM). The CO2-supported solid adsorbent was airtightly placed between two CaF2 windows and a Teflon spacer in a sample cell, i.e., a temperature cell combined with a thermostat for setting the cell temperature. The solid adsorbent filled approximately half of the temperature cell. Absorption was measured at a 0.12 × 0.12 mm spot at the location of the solid adsorbent. Gas inside the cell was measured at a 0.12 × 0.12 mm spot in the location without the solid adsorbent. The light output was 7 mW.

[0052] Figure 4A shows the IR absorption spectra of a CO2-supported solid adsorbent (amine-functionalized MOF) before and after irradiation using an FTIR microscope. The solid adsorbent region investigated was irradiated with a total light energy of 0.14 joules for 50 hours. The light intensity was 0.005 W / cm². 2 As shown in Figure 4B, when irradiated, the concentration of CO2 gas increased within the temperature cell.

[0053] The temperature of the solid adsorbent was tracked with a temperature sensor. During 50 hours of irradiation, the temperature remained constant at 23°C. Therefore, instead of a temperature increase, CO2 release from the solid adsorbent due to IR irradiation was demonstrated.

[0054] The number of photons absorbed by the solid adsorbent is 10 18 It was smaller than that, but the sample area examined was about 10 18 This is because the sample was irradiated with only a few photons, and only about 50% of the photons may have interacted with the sample and been absorbed. This gives approximately one photon for every 1000 absorbing groups, which indicates CO2 release via a single-photon absorption process. These results also indicate that activation of vibrational modes in the electronic ground state of a CO2-supported solid adsorbent, in this case a carbamate, leads to CO2 release.

[0055] This is very rare because, instead of the photon energy being dispersed over the manifold of the vibrational modes of the solid adsorbent, it is used to release CO2. Furthermore, the expected binding energy (about 5850 cm -1 ) is about twice as high as the single photon energy absorbed.

[0056] The release of CO2 from the solid adsorbent by electromagnetic radiation via a single photon process has not been observed previously. In particular, the CO2 release occurs upon interaction with photons having an energy that is extremely low, either 300 cm -1 below or 600 cm -1 below the CO2 binding energy at room temperature, which is surprising and unexpected. The induction of a ground state reaction, i.e., the release of CO2 from the supported solid adsorbent, by interacting with photons having an energy that is extremely low, 300 cm -1 below the binding energy, cannot be explained by using the photon energy to overcome the binding energy. At temperatures lower than room temperature, i.e., a minimum of 213 Kelvin (K) and a maximum of 423 K, the release of CO2 upon interaction with photons having an energy that is extremely low, either 300 cm -1 below or 600 cm -1 below the CO2 binding energy at a given temperature is surprising and unexpected. Suitable temperature ranges can be from about 213 K to about 373 K, or from about 213 K to about 333 K, or from about 233 K to about 313 K, or from about 253 K to about 353 K, or from about 213 K to about 303 K.

[0057] In addition to the photon energy, the intensity of the electromagnetic radiation also promotes the release of CO2 from the solid adsorbent. To demonstrate this effect, a CO2-supported solid adsorbent was irradiated for 5 minutes at an output of 2 mW using short laser pulses of about 300 fs with a repetition rate of 1 kHz and a wave number (FWHM) of 2650 cm -1 ~2400 cm -1 . An intensity of about 50 MW / cm 2 and a total energy of 0.0007 joules were irradiated at the position of the investigated solid adsorbent. Figure 5A, similar to the continuous wave irradiation of Figure 4A, shows at 2500 cm -1This shows a 15% decrease in the carbamate marker band. Here, the irradiation duration in Figure 5A was only 5 minutes, compared to 50 hours in Figure 4A. This demonstrates that even at similar total energy levels, increasing the intensity significantly increases CO2 emissions. Temperature changes during the process were negligible.

[0058] In Figure 5B, irradiation with femtosecond laser pulses is 50 MW / cm². 2 This enables exceptional strength. 12500cm -1 (or 800 nm) used a total energy of 0.24 joules in the observed material region. 2500 cm -1 A change of approximately 8% was observed across a wide absorption band in the vicinity. At 800 nm, the time period of the light pulse is several femtoseconds. This means that the direction of the electric field of the electromagnetic radiation is reversed on this time scale. Since the solid adsorbent does not absorb at 800 nm, the observed change is due to interaction with a strong electric field. Because the direction changes on a very fast time scale, CO2 emission is not observed or is negligible, but a change in the characteristics of the vibration band is seen. In other words, the strong electric field changes the geometry of the solid adsorbent. However, the fast vibration period hinders CO2 emission because the direction of the interaction between the charged groups in the CO2-supported solid adsorbent and the electric field changes too quickly.

[0059] Using lower frequencies results in slower electric field oscillations. This leads to slower changes in the direction of the electric field interacting with matter. Slower electric field oscillations can be achieved using frequencies as low as 2.45 GHz. In this frequency range, the electric field changes on a timescale of 100 picoseconds to nanoseconds. Within this time window, emitted CO2 molecules can leave their insertion site and are no longer affected by the opposite electric field direction.

[0060] Figure 6 shows CO2 emission induced by microwave electromagnetic radiation on a CO2-supported solid adsorbent (amine-functionalized MOF). At constant microwave power and frequency, there are two peaks around 180 seconds and 350 seconds. Figure 7B shows a similar CO2 emission profile when a microwave energy of 2.45 GHz is applied to the CO2-supported solid adsorbent (amine-functionalized MOF). This indicates two CO2 emission channels.

[0061] In contrast, as shown in Figure 7A, CO2 emissions are monitored as the temperature rises, and there is a single peak around 4 minutes when CO2 emissions are induced by heating / temperature rise without electromagnetic radiation.

[0062] Figure 8 shows that increasing microwave power increases CO2 emissions. The CO2 emission profile is shown in Figure 8. This figure shows that at the same temperature, CO2 emissions increased significantly at a power output of 1,000 W compared to 700 W. The overall trend indicates that at the same temperature, higher microwave power results in higher CO2 emissions.

[0063] Various aspects of this disclosure are described.

[0064] Embodiment 1. A method for selectively releasing CO2 from a CO2-supported solid adsorbent, wherein the CO2 release rate is 0.7 W / cm². 2 A method comprising applying electromagnetic radiation having the above intensity and frequency of approximately 400 THz to approximately 70 kHz to a CO2-supported solid adsorbent to release CO2, wherein the CO2-supported solid adsorbent comprises a solid adsorbent, chemically adsorbed CO2, and physically adsorbed CO2, and the solid adsorbent comprises at least one amine compound.

[0065] Apparatus 2. Electromagnetic radiation is approximately 0.7 W / cm² in the case of continuous emission. 2 ~Approx. 1500W / cm 2 It has an intensity of approximately 5 W / cm² in the case of pulsed radiation. 2 ~About 500GW / cm 2 The method according to embodiment 1, having the strength of [the specified value].

[0066] Embodiment 3. The method according to Embodiment 1 or 2, wherein carbon dioxide is selectively emitted by energy generated by vibrational excitation via a single-photon process.

[0067] Embodiment 4. The method according to any one of Embodiments 1 to 3, wherein the CO2-supported solid adsorbent includes charged groups or partially charged groups, and a Coulomb force applied by electromagnetic radiation acts on the charged groups or partially charged groups to release CO2.

[0068] Embodiment 5. The method according to any one of Embodiments 1 to 4, wherein the electromagnetic radiation has a photon energy lower than the binding energy between carbon dioxide and the solid adsorbent.

[0069] Appearance 6. Electromagnetic radiation is approximately 400 cm -1 ~About 4000cm -1 The method according to any one of embodiments 1 to 5, having the wavenumber.

[0070] Embodiment 7. The method according to any one of Embodiments 1 to 6, wherein the temperature difference of the solid adsorbent before and after the selective release of CO2 is less than approximately 10°C.

[0071] Embodiment 8. The method according to any one of Embodiments 1 to 7, wherein the electromagnetic radiation has a frequency of approximately 120 THz to approximately 0.07 MHz.

[0072] Embodiment 9. The method according to any one of Embodiments 1 to 8, wherein the amount of carbon dioxide emitted increases with increasing intensity of electromagnetic radiation at the same temperature and frequency.

[0073] Embodiment 10. The CO2-supported solid adsorbent contains co-adsorbent water, according to any one of Embodiments 1 to 9.

[0074] Embodiment 11. The method according to any one of Embodiments 1 to 10, wherein the CO2-supported solid adsorbent comprises at least one of carbonate ions, bicarbonate ions, ammonium ions, carbamates, or carbamic acid.

[0075] Embodiment 12. The solid adsorbent has a pore size of approximately 0.4 nm to approximately 10 μm, according to any one of Embodiments 1 to 11.

[0076] Embodiment 13. The solid adsorbent having a thermal conductivity of less than 0.1 W / mK, according to any one of Embodiments 1 to 12.

[0077] Embodiment 14. The method according to any one of Embodiments 1 to 13, wherein the solid adsorbent further comprises a metal portion.

[0078] Embodiment 15. The method according to any one of Embodiments 1 to 14, wherein the solid adsorbent further comprises an organic linker.

[0079] Embodiment 16. The method according to any one of Embodiments 1 to 15, wherein the solid adsorbent is a metal-organic structural material functionalized with an amine compound.

[0080] Embodiment 17. The method according to any one of Embodiments 1 to 16, wherein less than 10% of carbon dioxide is released when the CO2-supported solid adsorbent is stored at 20°C and atmospheric pressure for one week without exposure to electromagnetic radiation.

[0081] Embodiment 18. The method according to any one of Embodiments 1 to 17, wherein the solid adsorbent exists in the form of pellets.

[0082] Embodiment 19. The method according to any one of Embodiments 1 to 18, wherein the solid adsorbent exists in the form of a coating.

[0083] Embodiment 20. The method according to any one of Embodiments 1 to 19, wherein the solid adsorbent exists in the form of a self-supporting monolith.

[0084] Embodiment 21. The method according to any one of Embodiments 1 to 20, wherein the temperature of the solid adsorbent is in the range of approximately 213K to approximately 423K, and optionally in the range of approximately 213K to approximately 373K.

[0085] Embodiment 22. A method for removing carbon dioxide from a gaseous environment or exhaust gas flow, comprising: exposing a solid adsorbent to a gaseous environment or exhaust gas flow; removing CO2 from the gaseous environment or exhaust gas flow to form a CO2-supported solid adsorbent; and 0.7 W / cm² 2 A method comprising applying electromagnetic radiation having the above intensity and frequency of approximately 400 THz to approximately 70 KHz to a CO2-supported solid adsorbent to release CO2 and regenerate the solid adsorbent, wherein the CO2-supported solid adsorbent comprises a solid adsorbent and chemically adsorbed CO2, physically adsorbed CO2, or a combination thereof, and the solid adsorbent comprises at least one amine compound.

[0086] Embodiment 23. The method according to Embodiment 22, wherein the CO2-supported solid adsorbent contains charged groups or partially charged groups, and a Coulomb force applied by electromagnetic radiation acts on the charged groups or partially charged groups to release CO2.

[0087] Embodiment 24. The method according to Embodiment 22 or 23, wherein the electromagnetic radiation has a single-photon energy lower than the binding energy between carbon dioxide and the solid adsorbent.

[0088] In the context of this description of the present invention (in particular in the following claims), the terms “a,” “an,” and “the,” and similar reference subjects, should be construed as encompassing both singular and plural unless otherwise indicated herein or unless explicitly contradicted by the context. The terms “about,” “substantially,” and “generally” are intended to include the degree of error relating to the measurement of a particular quantity based on the apparatus available at the time of filing this application. For example, “about” and / or “substantially” and / or “generally” may include a range of ±8%, 5%, or 2% of a given value.

[0089] Unless otherwise defined, technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this invention pertains.

[0090] All references cited herein are incorporated by reference in their entirety. Typical embodiments are described for illustrative purposes, but the foregoing description should not be considered a limitation to the scope of this specification. A person skilled in the art will be able to come up with various modifications, adaptations, and alternatives without departing from the spirit and scope of this specification.

Claims

1. CO ２ CO2 from supported solid adsorbent ２ A method for selectively releasing, Electromagnetic radiation having an intensity of 0.7 watts / square centimeter or more and a frequency of approximately 400 terahertz to approximately 70 kilohertz, the CO ２ When applied to a supported solid adsorbent, CO ２ Characterized by releasing, The aforementioned CO ２ The supported solid adsorbent consists of a solid adsorbent and chemically adsorbed CO2. ２ , physically adsorbed CO ２ , or combinations thereof, The method comprising the solid adsorbent containing at least one amine compound.

2. The method according to claim 1, wherein the electromagnetic radiation has an intensity of about 0.7 watts / cm² to about 1500 watts / cm² in the case of continuous radiation, or an intensity of about 5 watts / cm² to about 500 gigawatts / cm² in the case of pulsed radiation.

3. The method according to claim 1, wherein the carbon dioxide is selectively emitted by energy generated by vibrational excitation via a single-photon process.

4. The CO ２ supporting solid adsorbent contains a charged group or a partially charged group, and the Coulomb force applied by the electromagnetic radiation acts on the charged group or the partially charged group to release CO ２ The method according to claim 1, which is released.

5. The method according to claim 1, wherein the electromagnetic radiation has a photon energy lower than the binding energy between the carbon dioxide and the solid adsorbent.

6. The aforementioned electromagnetic radiation is approximately 400 cm －１ ~Approx. 4000cm －１ The method according to claim 1, having the wavenumber.

7. The aforementioned CO ２ The method according to claim 6, wherein the temperature difference of the solid adsorbent before and after the selective release is less than about 10°C.

8. The method according to claim 1, wherein the electromagnetic radiation has a frequency of about 120 terahertz to about 0.07 megahertz.

9. The method according to claim 1, wherein the amount of carbon dioxide emitted increases with increasing intensity of electromagnetic radiation at the same temperature and frequency.

10. The aforementioned CO ２ The method according to claim 1, wherein the supported solid adsorbent contains co-adsorbed water.

11. The aforementioned CO ２ The method according to claim 1, wherein the supported solid adsorbent comprises at least one of carbonate ions, bicarbonate ions, ammonium ions, carbamates, or carbamic acid.

12. The method according to claim 1, wherein the solid adsorbent has a pore size of about 0.4 nanometers to about 10 micrometers, a thermal conductivity of less than 0.1 watts / meter-Kelvin, or a combination thereof.

13. The method according to claim 1, wherein the solid adsorbent further comprises a metal portion, and optionally further comprises an organic linker.

14. The method according to claim 1, wherein the solid adsorbent is a metal-organic structural material functionalized with the amine compound.

15. A method for removing carbon dioxide from a gaseous environment or exhaust gas flow, Exposing a solid adsorbent containing at least one amine compound to the gaseous environment or the exhaust gas flow, CO from the gaseous environment or the exhaust gas flow ２ Remove CO ２ Forming a supported solid adsorbent, The CO ２ CO2 from supported solid adsorbent ２ A method comprising selectively releasing a substance.

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