Apparatus, method and system for direct air capture using electromagnetically stimulated radiation desorption of solid amine sorbents releasing carbon dioxide

Abstract

One embodiment of the present invention is directed to a method, apparatus, and system that uses a solid amine sorbent to capture carbon dioxide from air and a radio frequency generator to desorb the carbon dioxide by directly exciting the amine-carbon bond, thereby significantly reducing the energy cost of releasing the carbon dioxide. In an alternative embodiment of the present invention, a method, apparatus, and system for capturing carbon dioxide from air uses a solid amine sorbent and a microwave generator to desorb the carbon dioxide by directly exciting the amine-carbon bond, thereby significantly reducing the energy cost of releasing the carbon dioxide.

Description

[Technical Field]

[0001] The present invention relates to methods, compositions and apparatus for efficiently capturing carbon dioxide from the atmosphere and for regenerating sorbents used to capture carbon dioxide. [Background technology]

[0002] Anthropogenic greenhouse gas emissions are the primary cause of global warming, with carbon dioxide being the main contributor from both point and distributed sources. Post-combustion carbon capture is an effective short-term mitigation strategy to combat carbon dioxide emissions, but because one-third of carbon dioxide emissions come from point sources and scaling up post-combustion carbon capture and storage technologies is difficult and progressing slowly, negative carbon dioxide technologies need to be adopted to avoid excess carbon dioxide emissions.

[0003] Net carbon dioxide (CO2) emissions, which include industrial manufacturing as well as energy services, transportation, land use, and domestic demand met by agriculture, are an important factor in stabilizing the global average temperature. Some energy services, such as heating and cooling, whether for domestic or industrial use, could be obtained primarily by generating electricity from renewable energy sources. However, industrial processes that necessarily utilize and release carbon dioxide into the atmosphere present a problem with serious consequences. In addition, carbon dioxide is a product widely used in industry for a wide variety of purposes, such as in the food and beverage and agricultural sectors. Summary of the Invention

[0004] In one embodiment of the present invention, carbon dioxide removal from the atmosphere is carried out using a DAC with a sorbent and release of carbon dioxide using microwave (MW) irradiation to regenerate the sorbent. In one embodiment of the present invention, carbon dioxide removal from the atmosphere is carried out using a DAC with a polyamine sorbent and release of carbon dioxide using microwave (MW) irradiation to regenerate the polyamine sorbent. In one embodiment of the present invention, carbon dioxide removal from the atmosphere is carried out using a DAC with a polyamine sorbent and release of carbon dioxide using radio frequency (RF) irradiation to regenerate the polyamine sorbent. In one embodiment of the present invention, the polyamine sorbent may be polyethyleneimine (PEI). In one embodiment of the present invention, the PEI sorbent may be grafted or loaded onto a solid support. In one embodiment of the present invention, the solid support may be cellulose acetate, gamma alumina, titania, or functionalized cellulose acetate silicon dioxide. In an alternative embodiment of the present invention, the polyamine sorbent may be a branched PEI functionalized cellulose acetate silicon dioxide sorbent material. In one embodiment of the present invention, MW irradiation energy consumption may be monitored to optimize the time required for efficient regeneration of the polyamine sorbent, thereby increasing carbon dioxide removal. In one embodiment of the present invention, MW swing technology utilizes a laminar flow contactor with a solid amine sorbent coupled with a MW swing desorption (MWSD) step. In one embodiment of the present invention, a continuous mechanism may be employed to move the contactor through the MW desorption cavity. In an alternative embodiment of the present invention, a process of moving the resonant cavity and waveguide around the sorbent material may be employed. [Brief explanation of the drawings]

[0005] The present invention has been described with reference to specific embodiments thereof. Additional aspects can be seen from the drawings.

[0006] [Figure 1A]FIG. 1 is a schematic diagram showing one of multiple holders 1040 with associated monolith contactor 1035 with associated adsorbent (not labeled) exposed to laminar air flow 1060 generated by fan 1030, according to one embodiment of the present invention. [Figure 1B] FIG. 1 is a schematic diagram showing a holder 1040 with an associated monolith contactor 1035 with an associated adsorbent (not labeled) inserted through a gas-tight inlet 1045 into a resonant cavity 1015, where a microwave or radio frequency source 1010 and waveguide 1080 are used to irradiate the adsorbent and a vacuum port 1025 is used to evacuate carbon dioxide, according to various embodiments of the present invention. [Figure 1C] Schematic diagram showing a holder 1040 with an associated monolith contactor 1035 with an associated adsorbent (not labeled) inserted through a gas-tight inlet 1045 into a resonant cavity 1015, where a microwave or radio frequency source 1010, a waveguide 1080 and a tuning element 1070 are used to irradiate the adsorbent, a vacuum port 1025, and a vacuum pump 1020 exhausts carbon dioxide, according to various embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0007] definition The transitional term "comprising" is synonymous with "including," "containing," or "characterized by" and is inclusive or open-ended, and does not exclude additional, unrecited elements or method steps.

[0008] The transitional phrase "consisting of" excludes any element, step, or ingredient not specified in the claim, but does not exclude additional ingredients or steps that are extraneous to the invention, such as impurities normally associated with compositions.

[0009] The transitional phrase "consisting essentially of" limits the scope of the claim to those materials or steps specified and those that do not materially affect the basic and novel characteristics of the claimed invention.

[0010] Metals include lithium, beryllium, boron, carbon, nitrogen, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, arsenic, selenium, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, indium, and sulfur. The term "metal oxide" refers to a metal oxide that contains one or more of the elements: zinc, antimony, tellurium, cesium, barium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, bismuth, polonium, francium, and radium.

[0011] The plastics include one or more of polystyrene, high impact polystyrene, polypropylene, polycarbonate, low density polyethylene, high density polyethylene, polypropylene, acrylonitrile butadiene styrene, polyphenyl ether alloyed with high impact polystyrene, expanded polystyrene, polyphenylene ether and polystyrene impregnated with pentane, and blends of polyphenylene ether and polystyrene impregnated with pentane or polyethylene and polypropylene.

[0012] Polymers include styrene, propylene, carbonate, ethylene, acrylonitrile, butadiene, vinyl chloride, vinyl fluoride, ethylene terephthalate, terephthalate, dimethyl terephthalate, bis-beta-terephthalate, naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, 6-hydroxynaphthalene-2-carboxylic acid, monoethylene glycol (1,2 ethanol), cyclohexylene dimethanol, 1,4-butanediol, 1,3-butanediol, polyester, cyclohexanedimethanol, terephthalic acid, isophthalic acid, methylamine, ethylamine, ethanolamine, dimethylamine , hexamethylaminediamine (hexane-1,6-diamine), pentamethylenediamine, methylethanolamine, trimethylamine, aziridine, piperidine, N-methylpiperidine, formaldehyde anhydride, phenol, bisphenol A, cyclohexanone, trioxane, dioxolane, ethylene oxide, adipoyl chloride, adipic acid, adipic acid (hexanedioic acid), sebacic acid, glycolic acid, lactide, caprolactone, aminocaproic acid, aziridine, and / or mixtures of two or more materials synthesized from the polymerization of these reagents.

[0013] A "contactor" is a crucible used to hold or contain the adsorbent. In one embodiment of the invention, the contactor is partially transparent to radio frequencies or microwaves. In an alternative embodiment of the invention, the contactor contains specific covalent groups that allow for specific radio frequency or microwave absorption. In one embodiment of the invention, the contactor is made from polytetrafluoroethylene (PTFE), a polymer with a low dielectric constant, an alumina-based ceramic, corundum, a titanium-based ceramic, a zeolite, fused silica, or the like to minimize absorption at the resonant cavity frequency. In one embodiment of the invention, the contactor is made from a porous ceramic. In one embodiment of the invention, the porous ceramic is silicate, aluminosilicate, diatomaceous earth, carbon, corundum, silicon carbide, or cordierite. In an alternative embodiment of the invention, the contactor may be cellulose acetate. In an alternative embodiment of the invention, the contactor may be mesoporous silica. In an alternative embodiment of the invention, the contactor is made from a glass-coated ferromagnetic material. In an alternative embodiment of the invention, the contactor is made from MnFeO. In an alternative embodiment of the invention, the contactor is PTFE impregnated with a non-aqueous hydroxyl-containing molecule. In another alternative embodiment of the invention, the contactor is PTFE derivatized with hydroxyl groups.

[0014] By resonant cavity is meant a vessel suitable for radio frequency and / or microwave desorption of carbon dioxide.

[0015] A sorbent is a material capable of forming bonds with carbon dioxide molecules present in the air. Carbon dioxide molecules in the feed material to be treated are absorbed or adsorbed by the sorbent. In one embodiment of the present invention, the feed material is atmospheric air. In one embodiment of the present invention, the sorbent is a polyamine sorbent. In one embodiment of the present invention, the sorbent is a plastic impregnated with an amine. In one embodiment of the present invention, the sorbent is selected from the group consisting of linear PEI, branched PEI, linear PEI-functionalized cellulose acetate silicon dioxide, branched PEI-functionalized cellulose acetate silicon dioxide, PAA poly(allylamine), and PPI poly(propyleneimine).

[0016] A gas-tight inlet refers to an opening that separates the outside from the inside (e.g., of a resonant cavity) through which a material, such as a contactor, can pass from one side to the other (e.g., when loading a contactor into the resonant cavity), but which, when sealed, restricts the passage of gas molecules from one side to the other. In one embodiment of the present invention, a gas-tight inlet of a resonant cavity with an attached vacuum pump is capable of maintaining a vacuum differential between the outside and the inside of the gas-tight inlet of about 0.2 bar. In this range, about means plus or minus 30 percent.

[0017] The cavity is tailored to provide uniform heating through design of the geometric dimensions of the processing cavity, and may include active manipulation of electromagnetic standing waves through various methods such as movement of dielectric material through the cavity, stirring or movement of microwave absorbing material through the cavity.

[0018] Deployed means attached, affixed, adhered, inserted, or otherwise associated. A reservoir is a container used to contain one or more liquid, gas, or solid samples.

[0019] In the following description, various aspects of the present invention are described. However, it will be apparent to one skilled in the art that the present invention may be practiced using only some or all aspects of the present invention. For purposes of explanation, specific numbers, materials, and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known features have been omitted or simplified so as not to obscure the present invention.

[0020] Carbon dioxide and CO2 are used interchangeably herein.

[0021] Direct air capture (DAC), which involves the removal and concentration of carbon dioxide from the air and where the carbon dioxide is either sequestered underground or upconverted into materials such as concrete, polymers, and carbon fiber, is considered an attractive and scalable carbon mitigation pathway strategy. DAC has the potential to achieve net-negative emissions on the scale of several GT per year by 2050. However, the technology, costs, and processing steps involved in DAC limit its application to large-scale implementations and are not suitable for market adoption, which requires compression, liquefaction, storage, and transportation of carbon dioxide to commercial customers. On-site production of carbon dioxide from DAC for existing carbon dioxide-using industries could reduce the cost of carbon dioxide to customers and provide a more sustainable supply while meeting emission reduction targets / requirements.

[0022] DAC requires contact of carbon dioxide from air with an adsorbent, followed by desorption of the carbon dioxide to capture the gas. Currently, two leading methods for carbon dioxide capture are commercially or pre-commercially available: aqueous alkali and amines. Each method has a preferred carbon dioxide release or extraction system. "Steam stripping" systems provide the energy needed to break the amine-carbon dioxide chemical bond when amines are used to capture carbon dioxide. Amine systems are generally described in two categories: liquid amine contactors and solid amine contactors (including amine-bound MOFs). However, amines can be degraded under oxidative conditions and high temperatures, or in the presence of humidity or water vapor. Alkaline-liquid systems contact carbon dioxide from air with aqueous alkali to form carbonates, which are then decomposed using heat to produce carbon dioxide, but require significant capital and energy costs and are not suitable for applications that fit into commercial carbon dioxide markets without transportation.

[0023] DAC requires the contact of carbon dioxide from air with an adsorbent and subsequent desorption of the carbon dioxide to capture the gas. Currently, there are two prevalent methods for carbon dioxide capture: (i) absorption via aqueous alkaline solutions and (ii) adsorption via amine chemisorption or zeolite physisorption. Aqueous alkaline systems involve contacting gaseous carbon dioxide (from air) with an aqueous alkaline solution to produce carbonate salts, thereby removing carbon dioxide from the air. The carbonate salts are then decomposed using heat to generate carbon dioxide and regenerate the aqueous alkaline solution. This process requires significant capital and energy costs. It is not suitable for applications that meet the commercial carbon dioxide market without transportation. Amine systems are generally described in two categories: liquid amine contactors and solid (polymeric) amine contactors, including amine-linked metal-organic frameworks (MOFs). Solid polymeric amine systems are typically impregnated or grafted onto porous support structures such as silica, clay, zeolites, and carbon. Polymeric amine DAC systems require CO2 regeneration via heat (TSA, thermal swing adsorption), pressure (VSA, vacuum swing adsorption), or a combination thereof (TVSA, thermal vacuum swing adsorption).

[0024] CO2 is useful to industry, and DAC can enable a lower-cost, more sustainable supply of CO2 to existing and future markets. Furthermore, CO2 from DAC can replace existing CO2 sources used by industry, which ultimately increase the CO2 load in the atmosphere. DAC can be used to meet industry's emission reduction requirements.

[0025] The primary considerations in designing a DAC system are a) the energy cost of contacting the carbon dioxide with the adsorbent, b) the regeneration of the adsorbent, and c) the capital and maintenance costs of the system.

[0026] DAC requires moving large volumes of air through the adsorbent contactor due to the low CO2 concentration in air. Therefore, the energy cost of contacting carbon dioxide via air movement dictates that low-pressure drop contactors, such as laminar flow contactors, are significantly preferable to alternative embodiments. This is because the pressure drop and therefore energy consumption of laminar flow contactors are linearly related to air velocity, whereas turbulence increases with the square of the air velocity and is therefore exponentially costly. In laminar flow contactors, carbon dioxide is driven toward the amine capture sites primarily through a diffusion gradient perpendicular to the airflow and secondarily by shear forces present in laminar flow. Furthermore, the pressure drop of the contactor is sufficiently low that it does not contribute significantly to the overall cost of the process. Extruded monolithic contactors, such as those used in automotive catalytic converters, have superior properties in that they maximize surface area per pressure drop, enabling high mass transfer for carbon dioxide adsorption in a laminar flow configuration.

[0027] Due to the fact that DAC requires contacting low concentrations of carbon dioxide from air at high mass flow rates, higher air velocities are preferred to maximize the amount of CO captured within a given contactor volume. This requires exponentially higher pressure drops and therefore energy costs. In laminar flow configurations within monolithic contactors, carbon dioxide is driven toward the amine capture sites primarily via diffusion gradients perpendicular to the airflow and secondarily by shear forces present in laminar flow. Therefore, contactors in laminar flow configurations maximize mass transfer while minimizing the energy costs associated with active DAC. Laminar flow configurations are even more preferable than turbulent flow because the diffusion forces for carbon dioxide capture occur rapidly and are the driving force that requires no additional energy input beyond the movement of air in laminar flow configurations. Figure 1A is a schematic diagram showing one of multiple holders 1040 with associated monolithic contactors 1035 with associated adsorbent (not labeled) exposed to a laminar flow 1060 of air generated by a fan 1030, according to one embodiment of the present invention.

[0028] Desorption represents the largest energy cost of DAC, and while it can be argued that utilizing waste heat would reduce desorption costs, this approach requires co-location with a waste heat source, limiting the market potential of DAC.

[0029] Commercially available monolithic contactors maximize the surface area per pressure drop, allowing for high mass transfer for carbon dioxide adsorption in laminar flow configurations. For DAC, the carbon dioxide loading of the contactor is a function of air velocity, amine loading, and carbon dioxide breakthrough efficiency. Alternative laminar flow contactor alternatives with sufficient porosity are also suitable. P=v air *A*Pd*1 / Eff fan formula 1

[0030] where P is the power (energy) requirement for moving air through the contactor, v is the air velocity given in m / s, and A is the air flow rate in m 2 is the front surface area of ​​the contactor given by, and Pd is the surface area in Pa (J / m 3 ) and Eff is the fan efficiency.

[0031] In one embodiment of the present invention, by operating in a laminar flow regime, the adsorbent can achieve up to 80% carbon dioxide capture.

number

[0032] The mass flow rate of carbon dioxide is kg / m 3 The density of air at STP is expressed as P air and v is given by m 2 is the air velocity expressed in m / s, and A is the 2 is the cross-sectional area of ​​the contactor, expressed as C co2 is the concentration of carbon dioxide in the air (0.04%).

number

[0033] Here, Eff co2 D ads is 90%. Therefore, the mass of carbon dioxide captured is 6.5 kg / hr, which is 124.5 kWh / MT (448 kJ / kg) of carbon dioxide at 806 W of power. Given the constraints of fan efficiency and carbon dioxide air concentration, the main ways to improve the energy efficiency of carbon dioxide capture via laminar flow contactors are to reduce the pressure drop (unlikely) or to increase the EFF CO2 , D ads or v air The primary goal is to increase the mass transfer of carbon dioxide which may require increasing the

[0034] In one embodiment of the present invention, the polyamine adsorbent may be linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilanes, and aminopropylorganosilanes. In alternative embodiments of the present invention, the polyamine adsorbent may be a linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, a branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, a metal-organic framework-incorporated linear PEI, a metal-organic framework-incorporated branched PEI, and a metal-organic framework-incorporated amine. In another alternative embodiment of the present invention, the polyamine adsorbent may be a mesoporous material selected from the group consisting of polyethylene MCM-41, or an amino-modified M41S, FSM-16, and SBA-15, such as 3-trimethoxysilylpropyldiethylenetriamine SBA-15. In alternative embodiments of the present invention, alternative higher adsorption capacity adsorbents and alternative contactor materials may be used with the MWSD. For example, some amine-silica adsorbent materials that are known to decompose to some extent in the presence of steam may be useful in the present invention if desorption is under sufficiently anhydrous conditions.

[0035] Conventional steam stripping technology employs a desorption mechanism that utilizes a combination of vacuum and low-temperature steam to provide a rapid and reasonably efficient carbon dioxide desorption mechanism while reducing the primary deactivation mechanism, amine oxidation at high temperatures. The adsorption energy for PEI has been measured to be approximately 94 kJ / mol, or 2,350 kJ / kg of carbon dioxide. However, empirical data from commercially designed systems with multiple monoliths has been reported to require approximately 5,000 kJ / kg of carbon dioxide. Cooling of the monoliths for cyclic adsorption is achieved via drying of the wetted contactor surfaces via airflow, through which the thermal mass of the contactor is lost to the environment. As a result, the latent energy of the thermal mass of the desorption system is difficult to recover, limiting the overall energy efficiency and exergy of the system.

[0036] The heat of desorption is given by Equation 4 for a conventional isothermal regeneration process:

number

[0037] Here, the regeneration heat Q r (kJ / kg of adsorbed carbon dioxide), and q w is the adsorbent working capacity in wt% (typically 8-10% for PEI), C p,s is the specific heat of the adsorbent (kJ / kgK), which is approximately 1.81, and T de is the desorption temperature, and T ad is the adsorption temperature (typically a delta around 60), and H a is the heat of adsorption (kJ / kg of carbon dioxide) and is approximately 95, and Q v is the heat of vaporization of water at STP (2257.6 kJ / kg), and F H2O is the moisture absorption from the air in the adsorbent, and the last two depend on the relative humidity present during adsorption and the hydrophilicity of the adsorbent.

[0038] The total head of desorption is given by Equation 5: Q total=(1-α)Q r +(1-β)Q c +(1-γ)Q s formula 5

[0039] Here, Q c is the latent heat of the contactor (C p,c *dT) is the heat energy required, and Q s is the energy required for the remaining wet system components. Heat recovery is considered in the overall system design, and Q r >Q s >Q c However, due to the evaporative cooling of the contactor and polymer, the heat recovery efficiency is Q s >>Q r and Q c This becomes:

[0040] The second law efficiency of the desorption step is H a / Q r and the overall second law efficiency is given by (Ha+RT·ln(P / P o ), where P is the final pressure of pure carbon dioxide and P o is the initial partial pressure, R is the ideal gas constant, and T is the operating temperature.

[0041] Typical adsorbent loadings for contactors are about 30-40 wt. %. In this range, about means plus or minus 20 percent. In conventional VSAs and TVSAs, to provide structural stability against the reduced pressures of desorption, the desorption elements of the system become larger, requiring more mass with increased contactor frontal surface area, increasing thermal mass, reducing thermal efficiency with larger contactor frontal surface area, and increasing overall capital and energy costs.

[0042] Radio Frequency Exposure Radio frequency (RF) radiation includes radio waves and microwaves (MW). RF radiation is oscillating electromagnetic radiation in the frequency range of 20 kHz to 1 GHz. Typically, RF below about 1 GHz heats via ionic conduction, while MW above 1 GHz heats via dipole heating. In an alternative embodiment of the invention, RF radiation at about 27.2 MHz at room temperature will be used to excite carbamate bonds. In another embodiment of the invention, RF radiation at about 42 MHz at room temperature will be used to excite carbamate bonds. In another alternative embodiment of the invention, RF radiation at about 915 MHz at room temperature will be used to excite carbamate bonds. In this range, about means plus or minus 20 percent. In another alternative embodiment of the invention, the substrate is heated indirectly (without directly exciting the bonds), resulting in excitation of the carbamate bonds.

[0043] Microwave irradiation MW radiation is electromagnetic radiation in the frequency range of 1 GHz to 300 GHz. In one embodiment of the present invention, MW radiation of approximately 2.45 GHz is used at room temperature to excite the carbamate bond. In this range, approximately means plus or minus 20 percent. Most domestic "kitchen" MW ovens and dedicated MW reactors for chemical synthesis operate at a frequency of 2.45 GHz (corresponding to a wavelength of 12.24 cm) to avoid interference with telecommunications and cell phone frequencies. The energy of MW photons in this frequency range (0.0016 eV) is generally too low to break chemical bonds and is lower than the energy of Brownian motion. Therefore, 2.45 GHz microwave radiation requires additional energy to induce chemical reactions. Typically, RF below approximately 1 GHz heats via ionic conduction, while MW above 1 GHz heats via dipole heating coupled to the RF field.

[0044] MW heating occurs through the direct interaction of molecules with MW radiation, allowing instantaneous volumetric heating without the heat transfer limitations and heat losses associated with traditional conduction or convection heating modes. Microwaves interact directly with the molecules of the reaction mixture, transferring energy more quickly and efficiently than convection techniques that rely on thermal conductivity, where heat is transferred throughout the reactor assembly until the target desorption temperature is reached. Microwaves interact with molecules through two methods: dipole rotation and icon conduction.

[0045] Microwave-enhanced chemistry is based on the efficient heating of materials through the "microwave dielectric heating" effect. This phenomenon relies on the ability of a particular material (solvent or reagent) to absorb MW energy and convert it into heat. The electric component of an electromagnetic field causes heating primarily through two mechanisms: dipole polarization and ionic conduction. Irradiation of a sample at MW frequencies results in the alignment of dipoles or ions in the applied electric field. When the applied electric field oscillates, the dipoles or ions attempt to realign themselves with the alternating electric field, and in the process, energy is lost in the form of heat through molecular friction and dielectric losses. The amount of heat generated by this process is directly related to the ability of the host material to tune itself to the frequency of the applied electric field. If the dipoles do not have enough time to realign, or if they realign too quickly relative to the applied electric field, no heating will occur. The allocated 2.45 GHz frequency used in all commercial systems lies between these extremes, allowing time for the molecular dipoles to align in the electric field, but not follow the alternating electric field exactly.

[0046] In one embodiment of the present invention, the MW swing technique utilizes a laminar flow contactor with a solid amine adsorbent coupled with an MWSD step. In one embodiment of the present invention, a continuous mechanism for moving the contactor through the MW desorption cavity can be employed. In an alternative embodiment of the present invention, a process of moving the resonant cavity and waveguide around the adsorbent material may be employed.

[0047] The presence of moisture or atmospheric hydration of the amine resonates with the MW energy, thereby adding additional heat energy to the sorbent-CO2 bond.

[0048] In practice, MW heating generates standing waves that correlate with hot / high power spots and cold / low power spots based on the dimensions and frequency of the resonant cavity. In one embodiment of the present invention, uniform heating / power distribution throughout the system can ensure near-complete desorption of carbon dioxide. As the carbamate bonds resonate in the electric field, the loss factor (tan δ) changes until carbon dioxide desorption occurs, affecting the wave pattern.

[0049] In one embodiment of the present invention, the MW irradiation energy may be monitored to optimize the time required for efficient regeneration of the adsorbent, thereby improving the productivity and efficiency of the carbon dioxide removal process. In one embodiment of the present invention, the microwave generator may be coupled to a resonant cavity specifically designed for carbon dioxide desorption, with a class A / B amplifier that receives feedback from the cavity and operates as an oscillator to excite molecular vibrations in the adsorbent. In one embodiment of the present invention, a fan-type electric field agitator (electromagnetic wave agitator or mechanical agitator) is used to modify the molecular vibrations in the carbon dioxide-bound adsorbent generated by the MW irradiation, affecting the standing wave pattern. In one embodiment of the present invention, an electromagnetic wave reflector is used to modify the molecular vibrations in the carbon dioxide-bound adsorbent generated by the MW irradiation. In an alternative embodiment of the present invention, the microwave generator is adapted to allow scanning between variable frequencies to optimize the desorption process. In another alternative embodiment of the present invention, the microwave generator is adapted to allow pulse-width modulation. In one embodiment of the present invention, a microwave generator may be used to ensure uniform heating within the desorption cavity, enabling rapid and complete carbon dioxide desorption with a higher adsorption duty cycle and faster cooling compared to conventional heating. Given a mixture of different dielectrics, microwaves will selectively couple to the higher dielectric loss components. In one embodiment of the present invention, the system may be configured for self-frequency modulation, allowing the device to automatically seek out the frequency that maximizes carbon dioxide desorption and direct MW energy specifically toward desorption binding. As an unexpected result, the MWSD may specifically target the enthalpy of desorption without heating a significant amount of contactor thermal mass, in addition to using the minimum energy required for desorption.1B is a schematic diagram showing a holder 1040 with an associated monolith contactor 1035 with associated adsorbent (not labeled) inserted through a gas-tight inlet 1045 into a resonant cavity 1015, where a microwave or radio frequency source 1010 and waveguide 1080 are used to irradiate the adsorbent and carbon dioxide is evacuated through a vacuum port 1025. In one embodiment of the present invention, the resonant cavity 1015 is adapted to move relative to the holder 1040 to form a gas seal. Furthermore, MW energy utilization requires low capital cost equipment, does not require water for convective heat transfer, and is easily scalable. If water is present, it will couple with the electric field and heat up. 1C is a schematic diagram showing a holder 1040 with an associated monolith contactor 1035 with an associated adsorbent (not labeled) inserted through a gas-tight inlet 1045 into a resonant cavity 1015 where a microwave or radio frequency source 1010, waveguide 1080, and tuning element 1070 are used to irradiate the adsorbent, and a vacuum port 1025 and vacuum pump 1020 exhaust carbon dioxide. FIG. 1A is a schematic diagram showing one of multiple holders 1040 with an exposed, associated monolith contactor 1035 with an associated adsorbent (not labeled).

[0050] When an applied electric field oscillates, the dipoles or ionic fields attempt to realign themselves with the alternating electric field, and in the process, energy is lost in the form of heat through molecular friction and dielectric losses. The amount of heat generated by this process is directly related to the ability of the host material to tune itself to the frequency of the applied electric field. If the dipoles do not have enough time to realign, or if they realign too quickly relative to the applied electric field, no heating will occur. The allocated 2.45 GHz frequency used in most commercial systems falls between these two extremes, allowing molecular dipoles time to align within the electric field, but not exactly following the alternating electric field.

[0051] The heating characteristics of a particular substance (e.g., a solvent) under MW irradiation conditions depend on its dielectric properties. The ability of a particular substance to convert electromagnetic energy into heat at a given frequency and temperature is determined by the so-called loss factor tan δ. This loss factor is expressed as the quotient tan δ = ε'' / ε', where ε'' is the dielectric loss, which indicates the efficiency with which electromagnetic waves are converted into heat, and ε' is the dielectric constant, which describes the ability of molecules to be polarized by an electric field. For efficient absorption and therefore rapid heating, a reaction medium with a high tan δ value is required.

[0052] Maximum Power Point Tracking In one embodiment of the present invention, maximum power point tracking (MPPT) may be used to optimize the structural arrangement of components between the MW source, contactor location, adsorbent location and location on the contactor, microwave power density, and microwave geometry. MPPT has two components: instrument feedback and software control, resulting in the ability to modify microwave power density and / or geometry to provide more efficient heating of the adsorbent. In one embodiment of the present invention, MPPT provides feedback between several sensors within the device that can determine either a) how much energy is being absorbed by the adsorbent or b) that the EM field is providing uniform heating throughout the adsorbent device. In one embodiment of the present invention, MPPT feedback can be used to ensure desorption of bound carbon dioxide between a lower limit of about 40 percent and an upper limit of about 90 percent, optimizing the experimental conditions for the desorption process. In this range, about means plus or minus 20 percent.

[0053] The dominant DAC cost is related to the sensible heat requirements of the contactor. Commercially available extruded parallel channel monolith contactors impregnated with solid amine adsorbents have been shown to be the preferred embodiment for carbon dioxide adsorption from air due to their commercial availability, low pressure drop, high carbon dioxide capacity, and cyclic stability. Key factors in designing a practical, commercial DAC process are (i) adsorption capacity, (ii) adsorption kinetics, (iii) low pressure drop, (iv) practical adsorbent regeneration, and (v) long adsorbent life.

[0054] PEI is currently the preferred amine because it has been found to be very stable, maintaining sufficient carbon dioxide adsorption capacity in the presence of repeated steam cycles up to 120 °C. However, the most commonly used amine-silica adsorbent materials are known to decompose to some extent in the presence of steam. PEI is a widely available commercially available material that can be produced on a large scale, is available in many configurations with various chemical-physical properties, and can be produced by various methods, including MW heating. Significant research has been done showing that parallel-channel, low-pressure-drop monoliths with large mesopore volumes and fully adsorbing walls are preferable to those with washcoats. Many other adsorbents with high amine loadings or carbon dioxide binding efficiencies have been tested and have shown varying results for stability through repeated cycling at high temperatures, making them unsuitable for waste heat utilization.

[0055] Several studies and empirical process data indicate that the dominant contribution in cost to adsorption-based DAC is related to the sensible heat requirements of the monolith and adsorbent, which range from 50 to 70%, and are not easily recovered in steam-regenerated monolith processes.

[0056] Commercially available corderite materials have been shown to contribute significantly (25-45%) to the overall cost of the process, primarily due to their high specific heat capacity. Utilization of other mesoporous materials with lower specific heat capacities, such as gamma-alumina, whose Cp is approximately half that of corderite (0.8 vs. 1.4 J g -1 K -1), it has been the subject of significant development.

[0057] Significant research has been done on the use of alternative materials such as gamma-alumina in mesoporous contactors, MOFs, polymeric hollow fiber adsorbents, and others.

[0058] In one embodiment of the present invention, DAC embodiments utilize low-cost, low-pressure drop mesoporous contactors with commercially available, stable amines for a desorption process that maximizes second-law efficiency and adsorption duty cycle. The proposed technology utilizes commercially available, preferred laminar flow contactors (corderite and extruded mesoporous γ-alumina parallel channel monoliths) with commercially available solid amine sorbents coupled with a microwave-assisted desorption step. Due to the nature of the amine-carbon dioxide carbamate bond, the resulting carbamate exhibits dipole and ionic charges, which are directly excited via the electromagnetic fields present in MW radiation. In addition, the contactor monolith and carbon dioxide-poor sorbent do not possess a strong dipole moment compared to the carbamate or sorbent-CO2 bond and are therefore largely transparent to microwaves. When the sorbent captures carbon dioxide, the resulting carbamate bond assumes a dipole and resonates in the presence of MW frequency electromagnetic fields until carbon dioxide is released. Upon desorption, the adsorbent has a significantly reduced dipole and a significantly reduced capacity to absorb energy. Therefore, systems may be designed such that the energy used during the desorption step is primarily used for desorption, maximizing the second law efficiency of desorption and reducing the primary amine deactivation pathway of oxidation at high temperatures.

[0059] In one embodiment of the present invention, the key design requirements are (i) sufficient mass transfer of carbon dioxide adsorption coupled with efficient desorption energy consumption and cycle time, (ii) a laminar flow configuration that maximizes mass transfer while minimizing the energy costs associated with adsorption, and (iii) carbon dioxide adsorption via diffusion in a high mass air flow. Commercially available monolithic contactors maximize the surface area per pressure drop, allowing for high mass transfer of carbon dioxide adsorption in a laminar flow configuration. This technology employs a desorption mechanism that utilizes a combination of vacuum and low-temperature steam, which together provide a mechanism for carbon dioxide desorption while reducing the primary deactivation mechanism of amine oxidation at regeneration temperatures.

[0060] In one embodiment of the present invention, water may be added to the contactor prior to microwave desorption.

[0061] Other embodiments Embodiments contemplated herein include the following embodiments P1 to P69.

[0062] Embodiment P1. A direct air capture (DAC) device comprising: a contactor; a polyamine sorbent associated with the contactor, wherein a plurality of carbon dioxide molecules in the air that contact the polyamine sorbent form bonds with the polyamine sorbent; a vacuum pump; a resonant cavity comprising: a gas-sealable inlet adapted to allow the contactor to enter the resonant cavity and seal the resonant cavity; a vacuum port, wherein the vacuum pump is in gaseous communication with the vacuum port to evacuate the resonant cavity; and a microwave generator adapted to be electromagnetically coupled to the resonant cavity, wherein the microwave generator selects a microwave frequency that optimizes breaking of the bonds between the polyamine sorbent and the plurality of carbon dioxide molecules and is adapted to release the plurality of carbon dioxide molecules into the vacuum port, wherein the plurality of gaseous carbon dioxide molecules released by the microwave generator are removed from the resonant cavity through the vacuum port.

[0063] Embodiment P2. The DAC apparatus of embodiment P1, wherein the microwave frequency selected at room temperature is between a lower limit of about 0.95 GHz and an upper limit of about 2.5 GHz.

[0064] Embodiment P3. The DAC apparatus of embodiment P1, wherein the microwave generator is adapted to optimize irradiation at frequencies between a lower limit of about 1 GHz and an upper limit of about 3 GHz.

[0065] Embodiment P4. The DAC device of embodiment P1, wherein the microwave generator further includes a variable scanning microwave frequency having a lock-in amplifier that affects desorption of bound carbon dioxide molecules between a lower limit of about 40 percent and an upper limit of about 95 percent.

[0066] Embodiment P5. The DAC device of embodiment P1, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 0.1 bar and an upper limit of about 1 bar, where about means plus or minus 20 percent.

[0067] Embodiment P6. The DAC device of embodiment P1, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silica adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal-organic framework-incorporated linear PEI, metal-organic framework-incorporated branched PEI, metal-organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

[0068] Embodiment P7. A method of capturing carbon dioxide molecules from air, wherein release of the carbon dioxide molecules is inhibited, comprising: (A) exposing a contactor having an associated polyamine sorbent to a stream of air, wherein a plurality of carbon dioxide molecules form bonds with the polyamine sorbent; and (B) introducing the contactor into a resonant cavity, the resonant cavity having: (a) a gas-tight inlet adapted to seal the resonant cavity with the contactor within the resonant cavity; (b) a vacuum port in gaseous communication with a vacuum pump; and (c) an inlet electromagnetically connected to the resonant cavity. (C) sealing the resonant cavity; (D) evacuating the sealed resonant cavity; (E) irradiating the polyamine adsorbent with the selected microwave frequency to release a plurality of carbon dioxide molecules into the resonant cavity; and (F) removing the plurality of carbon dioxide molecules in the resonant cavity through the vacuum port using a vacuum pump.

[0069] Embodiment P8. The method of embodiment P7, wherein the water content of the resonant cavity evacuated in step (D) is between a lower limit of about 10 μg limit of detection (LOD) and an upper limit of about 10 mg LOD.

[0070] Embodiment P9. The air flow rate is approximately 0.5 m 2 / sec lower limit and about 5m 2 The method of embodiment P7, wherein the upper limit of 1 / second is between 1 / second and 1 / second.

[0071] Embodiment P10. A continuous direct air capture (DAC) apparatus, comprising: a moving stage; a plurality of contactors disposed on the moving stage; a polyamine sorbent associated with each of the plurality of contactors; an outlet adapted to pass a laminar flow of air over the polyamine sorbent associated with each of the plurality of contactors, wherein a plurality of carbon dioxide molecules in the air form bonds with the polyamine sorbent; the outlet; a vacuum pump; and a resonant cavity, the resonant cavity including one or more of the plurality of contactors having a sealable inlet and a sealable inlet adapted to allow one or more of the plurality of contactors to enter the resonant cavity and to seal the resonant cavity including one or more of the plurality of contactors. a resonant cavity including one or both of the outlets, a vacuum port in pneumatic connection with a vacuum pump adapted to evacuate the sealed resonant cavity, and a microwave generator adapted to be electromagnetically connected to the resonant cavity, the microwave generator having a microwave frequency selected to optimize breaking of bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules and adapted to release the plurality of carbon dioxide molecules into the vacuum port, and the plurality of gaseous carbon dioxide molecules released by the microwave generator are removed from the resonant cavity through the vacuum port.

[0072] Embodiment P11. The DAC apparatus of embodiment P10, wherein the microwave generator is adapted to vary the microwave frequency to optimize desorption of the plurality of carbon dioxide molecules.

[0073] Embodiment P12. The DAC apparatus of embodiment P10, wherein the microwave generator is adapted to enable pulse width modulation to optimize desorption of a plurality of carbon dioxide molecules.

[0074] Embodiment P13. The DAC apparatus of embodiment P10, wherein the microwave frequency is between a lower limit of about 0.9 GHz and an upper limit of about 2.5 GHz.

[0075] Embodiment P14. The DAC apparatus of embodiment P10, wherein the microwave generator is adapted to optimize irradiation at frequencies between a lower limit of about 0.9 GHz and an upper limit of about 300 GHz.

[0076] Embodiment P15. The DAC device of embodiment P10, wherein the microwave generator further includes a variable scanning microwave frequency with a lock-in amplifier to ensure desorption of carbon dioxide molecules between a lower limit of about 40 percent and an upper limit of about 95 percent.

[0077] Embodiment P16. The DAC apparatus of embodiment P10, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 1 mbar and an upper limit of about 50 mbar.

[0078] Embodiment P17. The DAC device of embodiment P10, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal-organic framework-incorporated linear PEI, metal-organic framework-incorporated branched PEI, metal-organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

[0079] Embodiment P18. A method for continuous capture of carbon dioxide molecules from air, wherein release of the carbon dioxide molecules is inhibited, comprising: (A) exposing a plurality of contactors, each of the plurality of contactors having a polyamine sorbent associated therewith, to a laminar flow of air, wherein the plurality of carbon dioxide molecules form bonds with the polyamine sorbent; (B) introducing one or more of the plurality of contactors into a resonant cavity, wherein: (a) one or both of a gas-sealable inlet and a gas-sealable outlet adapted to allow one or more of the plurality of contactors to (i) enter the resonant cavity, (ii) seal the resonant cavity with one or more of the plurality of contactors inside the resonant cavity, and (iii) exit the resonant cavity; (b) a vacuum port in gaseous communication with a vacuum pump; and (c) electromagnetically connected to the resonant cavity. (C) sealing the resonant cavity; (D) evacuating the sealed resonant cavity; (E) irradiating the polyamine adsorbent with the selected microwave frequency to release a plurality of carbon dioxide molecules into the resonant cavity; (F) removing the plurality of carbon dioxide molecules in the resonant cavity through a vacuum port using a vacuum pump; (G) removing one or more of the plurality of contactors from the resonant cavity; and (H) repeating steps (B) through (G) to continuously capture carbon dioxide molecules from the air while suppressing the release of the carbon dioxide molecules.

[0080] Embodiment P19. The method of embodiment P18 further comprising introducing humidity in one or both of step (A) and step (E).

[0081] Embodiment P20. A DAC device comprising: a contactor; a polyamine adsorbent associated with the contactor, wherein a plurality of carbon dioxide molecules in the air that contact the polyamine adsorbent form bonds with the polyamine adsorbent; a vacuum pump; a resonant cavity comprising a gas-tight inlet adapted to allow the contactor to enter the resonant cavity and seal the resonant cavity; a vacuum port, wherein the vacuum pump is in gaseous communication with the vacuum port to evacuate the resonant cavity; and a radio frequency generator adapted to be electromagnetically coupled to the resonant cavity, wherein the microwave generator selects a radio frequency that optimizes breaking of the bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules and is adapted to release the plurality of carbon dioxide molecules into the vacuum port, and wherein the plurality of gaseous carbon dioxide molecules released by the radio frequency generator are removed from the resonant cavity through the vacuum port.

[0082] Embodiment P21. The DAC device of embodiment P20, wherein the radio frequency is between a lower limit of about 12 MHz and an upper limit of about 14 MHz.

[0083] Embodiment P22. The DAC device of embodiment P20, wherein the radio frequency is between a lower limit of about 27 MHz and an upper limit of about 42 MHz.

[0084] Embodiment P23. The DAC apparatus of embodiment P20, wherein the radio frequency is between a lower limit of about 0.9 GHz and an upper limit of about 1 GHz.

[0085] Embodiment P24. The DAC apparatus of embodiment P20, wherein the radio frequency generator is adapted to optimize irradiation at frequencies between a lower limit of about 100 kHz and an upper limit of about 1 GHz.

[0086] Embodiment P25. The DAC apparatus of embodiment P20, wherein the output power of the radio frequency generator is adjustable between a lower limit of about 50 dBm and an upper limit of about 100 dBm.

[0087] Embodiment P26. The DAC apparatus of embodiment P20, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 1 mbar and an upper limit of about 50 mbar.

[0088] Embodiment P27. The DAC device of embodiment P20, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal-organic framework-incorporated linear PEI, metal-organic framework-incorporated branched PEI, metal-organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

[0089] Embodiment P28. The DAC apparatus of embodiment P20, further comprising a mechanical stirrer disposed within the resonant cavity to stir the electromagnetic field.

[0090] Embodiment P29. A DAC device as described in embodiment P20, further comprising mounting the contactor on a holder affixed to the moving stage to facilitate movement of the contactor and a static component disposed within the resonant cavity that does not move relative to movement of the contactor, wherein movement of the contactor relative to the static component stirs the electromagnetic field.

[0091] Embodiment P30. A DAC device as described in embodiment P20, further comprising mounting the contactor on a holder affixed to the moving stage to facilitate movement of the contactor and a static component disposed within the resonant cavity that does not move relative to the movement of the contactor, wherein movement of the contactor relative to the static component distributes heat uniformly within the resonant cavity.

[0092] Embodiment P31. The DAC apparatus of embodiment P20, wherein the movement of the contactors relative to the static component stirs the electromagnetic field when the contactors are thermally tuned therebetween.

[0093] Embodiment P32. A method of capturing carbon dioxide molecules from air, wherein release of the carbon dioxide molecules is inhibited, comprising: (A) exposing a contactor having an associated polyamine sorbent to a laminar flow of air, wherein a plurality of carbon dioxide molecules form bonds with the polyamine sorbent; and (B) introducing the contactor into a resonant cavity, the resonant cavity having: (a) a gas-sealable inlet adapted to allow the resonant cavity to seal while the contactor is within the resonant cavity; (b) a vacuum port in gas communication with a vacuum pump; and (c) electromagnetically coupling the resonant cavity to the resonant cavity. (C) sealing the resonant cavity; (D) evacuating the sealed resonant cavity; (E) irradiating the polyamine adsorbent with the selected radio frequency to release a plurality of carbon dioxide molecules into the resonant cavity; and (F) removing the plurality of carbon dioxide molecules in the resonant cavity through the vacuum port using a vacuum pump.

[0094] Embodiment P33. The method of embodiment P32, wherein the water content of the sealed resonant cavity after evacuation in step (D) is between a lower limit of about 10 μg LOD and an upper limit of about 10 mg LOD.

[0095] Embodiment P34. A DAC apparatus comprising: a moving stage; a plurality of contactors disposed on the moving stage; a polyamine adsorbent associated with each of the plurality of contactors; an outlet adapted to allow a laminar flow of air to pass over the polyamine adsorbent associated with each of the plurality of contactors, wherein a plurality of carbon dioxide molecules in the air form bonds with the polyamine adsorbent; the outlet; a vacuum pump; and a resonant cavity, wherein one or both of a sealable inlet and a sealable outlet are adapted to allow one or more of the plurality of contactors to enter the resonant cavity and to seal the resonant cavity containing one or more of the plurality of contactors. a resonant cavity including one or both of a closable inlet and a sealable outlet; a vacuum port in gaseous communication with a vacuum pump adapted to evacuate the sealed resonant cavity; and one or more radio frequency generators adapted to be electromagnetically coupled to the resonant cavity, one or more of the one or more microwave generators having a radio frequency selected to optimize breaking of bonds between the polyamine adsorbent and a plurality of carbon dioxide molecules and adapted to release a plurality of carbon dioxide molecules into the vacuum port, wherein the plurality of gaseous carbon dioxide molecules released by the one or more radio frequency generators are removed from the resonant cavity through the vacuum port.

[0096] Embodiment P35. A DAC device as described in embodiment P34, wherein the shape of the resonant cavity is designed based on a particular radio frequency or set of frequencies used by at least one of the one or more radio frequency generators to affect desorption of a plurality of carbon dioxide molecules.

[0097] Embodiment P36. The DAC apparatus of embodiment P34, wherein at least one of the one or more radio frequency generators is adapted to vary the radio frequency to optimize desorption of the plurality of carbon dioxide molecules.

[0098] Embodiment P37. The DAC apparatus of embodiment P34, wherein a mechanical element within the electromagnetic (EM) field is moved relative to the waveguide to affect the distribution of the EM field.

[0099] Embodiment P38. The DAC apparatus of embodiment P34, wherein at least one of the one or more radio frequency generators generates a radio frequency between a lower limit of about 12 MHz and an upper limit of about 14 MHz Torr.

[0100] Embodiment P39. The DAC apparatus of embodiment P34, wherein at least one of the one or more radio frequency generators generates a radio frequency between a lower limit of about 27 MHz and an upper limit of about 42 MHz Torr.

[0101] Embodiment P40. The DAC apparatus of embodiment P34, wherein at least one of the one or more radio frequency generators generates a radio frequency between a lower limit of about 0.9 GHz and an upper limit of about 1 GHz Torr.

[0102] Embodiment P41. The DAC apparatus of embodiment P34, wherein the radio frequency generator is adapted to optimize irradiation at frequencies between a lower limit of about 100 kHz and an upper limit of about 1 GHz.

[0103] Embodiment P42. The DAC apparatus of embodiment P34, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 0.2 bar and an upper limit of about 0.8 bar.

[0104] Embodiment P43. The DAC device of embodiment P34, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal-organic framework-incorporated linear PEI, metal-organic framework-incorporated branched PEI, metal-organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

[0105] Embodiment P44. The DAC apparatus of embodiment P34 further comprising a maximum power point tracking system for optimizing microwave frequency.

[0106] Embodiment P45. A method for continuous capture of carbon dioxide molecules from air, wherein release of the carbon dioxide molecules is inhibited, comprising: (A) exposing a plurality of contactors, each of the plurality of contactors having a polyamine sorbent associated therewith, to a laminar flow of air, wherein the plurality of carbon dioxide molecules form bonds with the polyamine sorbent; (B) introducing one or more of the plurality of contactors into a resonant cavity, the method comprising: (a) one or both of a gas-sealable inlet and a gas-sealable outlet adapted to allow one or more of the plurality of contactors to (i) enter the resonant cavity, (ii) seal the resonant cavity with one or more of the plurality of contactors inside the resonant cavity, and (iii) exit the resonant cavity; (b) a vacuum port in gaseous communication with a vacuum pump; and (c) electromagnetically coupled to the resonant cavity. (C) sealing the resonant cavity; (D) evacuating the sealed resonant cavity; (E) irradiating the polyamine adsorbent with the selected radio frequency to release a plurality of carbon dioxide molecules into the resonant cavity; (F) removing the plurality of carbon dioxide molecules in the resonant cavity through a vacuum port using a vacuum pump; (G) removing one or more of the plurality of contactors from the resonant cavity; and (H) repeating steps (B) through (G) to continuously capture carbon dioxide molecules from the air while suppressing the release of the carbon dioxide molecules.

[0107] Embodiment P46. The method of embodiment P45, wherein the radio frequency comprises pulse width modulation.

[0108] Embodiment P47. The method of embodiment P45, wherein the radio frequency generator is turned off to modulate the frequency.

[0109] Embodiment P48. The method of embodiment P45 further comprising passing the captured carbon dioxide over one or more compounds selected from the group consisting of molecular sieves, zeolites, and activated carbon.

[0110] Embodiment P49. The method of embodiment P45, further comprising using a maximum power point tracking system to optimize the microwave frequency.

[0111] Embodiment P50. The method of embodiment P45, further comprising tuning the contactor to heat within the 2.4 to 2.5 GHz band to conduct thermal energy to the polyamine adsorbent.

[0112] Embodiment P51. An amplifier for a DAC device comprising: a contactor; a polyamine adsorbent associated with the contactor, wherein a plurality of carbon dioxide molecules in the air that contact the polyamine adsorbent form bonds with the polyamine adsorbent; a vacuum pump; a resonant cavity, wherein the resonant cavity has a gas-tight inlet adapted to allow the contactor to enter the resonant cavity and seal the resonant cavity; a vacuum port, wherein the vacuum pump is in gaseous communication with the vacuum port to evacuate the resonant cavity; and a microwave generator adapted to be electromagnetically connected to the resonant cavity, wherein the resonant cavity for carbon dioxide desorption having a Class A / B amplifier is designed such that the resonant cavity operates as an oscillator when receiving feedback from the resonant cavity to excite molecular vibrations in the adsorbent.

[0113] Embodiment P52. The amplifier of the DAC apparatus of embodiment P51, further comprising a microwave generator adapted to scan and vary the frequency.

[0114] Embodiment P53. The amplifier of the DAC apparatus of embodiment P51 further comprising a microwave generator adapted to vary the pulse width modulation.

[0115] Embodiment P54. The amplifier of the DAC apparatus of embodiment P51, further comprising modulating frequency.

[0116] Embodiment P55. The amplifier of the DAC apparatus of embodiment P51, wherein the microwave generator is powered solely by a photovoltaic cell.

[0117] Embodiment P56. The amplifier of the DAC apparatus of embodiment P51, wherein the microwave generator is powered solely by a source of wind energy.

[0118] Embodiment P57. A method for producing carbon dioxide molecules from a continuous DAC apparatus, introducing a laminar flow of air into a resonant cavity comprising an inlet, an outlet, a moving stage, a contactor, and a polyamine adsorbent associated with the contactor, wherein a plurality of carbon dioxide molecules present in the air become covalently bonded to the polyamine adsorbent, and irradiating the polyamine adsorbent with microwave frequencies generated by a microwave generator, the microwave generator adapted to select the microwave frequency to optimize breaking of bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules releasing the carbon dioxide molecules.

[0119] Embodiment P58. The method of embodiment P7, wherein the air flow is laminar.

[0120] Embodiment P59. A continuous DAC apparatus comprising: a contactor; a polyamine adsorbent associated with the contactor; an outlet adapted to allow a flow of air to pass over the polyamine adsorbent associated with the contactor, wherein a plurality of carbon dioxide molecules in the air form bonds with the polyamine adsorbent; and a resonant cavity including one or both of a sealable inlet and a sealable outlet adapted to move through the contactor to allow contact with a microwave generator adapted to electromagnetically contact the resonant cavity, wherein the microwave generator is adapted to select a microwave frequency to optimize breaking of the bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules releasing the plurality of carbon dioxide molecules, and wherein the plurality of gaseous carbon dioxide molecules released by the microwave generator are removed from the resonant cavity.

[0121] Embodiment P60. The DAC apparatus of embodiment P59, wherein the microwave generator is adapted to vary the microwave frequency to optimize desorption of the plurality of carbon dioxide molecules.

[0122] Embodiment P61. The DAC apparatus of embodiment P59, wherein the microwave generator is adapted to enable pulse width modulation to optimize desorption of the plurality of carbon dioxide molecules.

[0123] Embodiment P62. The DAC apparatus of embodiment P59, wherein the microwave frequency is between a lower limit of about 0.9 GHz and an upper limit of about 2.5 GHz.

[0124] Embodiment P63. The DAC apparatus of embodiment P59, wherein the microwave generator is adapted to optimize irradiation at a frequency between a lower limit of about 0.9 GHz and an upper limit of about 3 GHz.

[0125] Embodiment P64. The DAC device of embodiment P59, wherein the microwave generator further includes a variable scanning microwave frequency with a lock-in amplifier to ensure desorption of carbon dioxide molecules between a lower limit of about 40 percent and an upper limit of about 95 percent.

[0126] Embodiment P65. The DAC apparatus of embodiment P59, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 1 mbar and an upper limit of about 50 mbar.

[0127] Embodiment P66. The DAC device of embodiment P59, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal-organic framework-incorporated linear PEI, metal-organic framework-incorporated branched PEI, metal-organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

[0128] Embodiment P67. The DAC apparatus of embodiment P58, further comprising a vacuum pump adapted to evacuate the resonant cavity and / or remove released carbon dioxide from the polyamine adsorbent.

[0129] Embodiment P68. The DAC apparatus of embodiment P67, wherein the vacuum pump reduces the pressure in the resonant cavity to between a lower limit of about 0.2 bar and an upper limit of about 1 bar.

[0130] Embodiment P69 The method of embodiment P7, wherein the water content of the resonant cavity is reduced to between a lower limit of about 10 percent and an upper limit of about 80 percent. In this range, about means plus or minus 30 percent.

[0131] While the systems, methods, and apparatus have been described by way of setting forth illustrative examples, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such details. Of course, for purposes of describing the systems, methods, and apparatus provided herein, it is not possible to describe every conceivable combination of components or methods. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the present invention, in its broader aspects, is not limited to the specific details, representative systems, methods, or apparatus shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicants' general inventive concept. Accordingly, this application is intended to cover such alterations, modifications, and variations that fall within the scope of the appended claims. Moreover, the foregoing description is not intended to limit the scope of the present invention. Rather, the scope of the present invention is to be determined by the appended claims and their equivalents.

Claims

1. 1. A method for capturing carbon dioxide molecules from air with inhibited release of the carbon dioxide molecules, comprising: (A) exposing a contactor (1035) to an air flow, wherein a polyamine sorbent is associated with said contactor (1035), said air flow being laminar, and wherein a plurality of carbon dioxide molecules form bonds with said polyamine sorbent; (B) introducing the contactor (1035) into a resonant cavity (1015), the resonant cavity (1015) comprising: (a) a gas-tight inlet adapted to seal the resonant cavity (1015) while the contactor (1035) is within the resonant cavity (1015); (b) a vacuum port (1025) in gas communication with a vacuum pump (1020); (c) a microwave generator (1010) adapted to be electromagnetically coupled to the resonant cavity (1015), the microwave generator (1010) adapted to select a microwave frequency to optimize bond disruption with the polyamine adsorbent; and (C) sealing the resonant cavity (1015); (D) evacuating the sealed resonant cavity (1015); (E) irradiating the polyamine adsorbent with a selected microwave frequency to release the plurality of carbon dioxide molecules into the resonant cavity (1015); (F) using the vacuum pump (1020) to remove a plurality of carbon dioxide molecules from the resonant cavity (1015) through the vacuum port (1025); A method comprising:

2. The water content of the resonant cavity (1015) in step (D) is A lower limit of 10 percent, An upper limit of 80 percent, The method of claim 1 , wherein the temperature is reduced during

3. The flow rate of the air flow is 0.5 m ２ / second lower limit, 10m ２ / second upper limit, and The method of claim 1 , wherein

4. 1. A continuous direct air capture (DAC) device comprising: a moving stage; a plurality of monolithic contactors (1035) disposed on the moving stage; a polyamine sorbent associated with each of said plurality of monolithic contactors (1035), said polyamine sorbent being capable of forming bonds with a plurality of carbon dioxide molecules in the air; an outlet adapted to pass a laminar flow of air over a polyamine adsorbent associated with each of the plurality of monolithic contactors (1035); A resonant cavity (1015) comprising: a sealable inlet and / or a sealable outlet adapted to allow one or more of the plurality of monolithic contactors (1035) to enter the resonant cavity (1015) and to seal the resonant cavity (1015) containing one or more of the plurality of monolithic contactors (1035); a vacuum port (1025) in gaseous communication with a vacuum pump (1020) adapted to evacuate the sealed resonant cavity (1015); a microwave generator (1010) adapted to be electromagnetically coupled to the resonant cavity (1015), the microwave generator (1010) being adapted to select a microwave frequency to optimize breaking of bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules and to release the plurality of carbon dioxide molecules into the vacuum port (1025), the plurality of gaseous carbon dioxide molecules released by the microwave generator (1010) being removed from the resonant cavity (1015) through the vacuum port (1025); a resonant cavity (1015) including: A continuous DAC device comprising:

5. The continuous DAC apparatus of claim 4 , wherein the microwave generator (1010) is adapted to vary the microwave frequency to optimize desorption of the plurality of carbon dioxide molecules.

6. The microwave frequency is A lower limit of 0.9 GHz; An upper limit of 1 GHz, 5. The continuous DAC device of claim 4, wherein:

7. The microwave generator (1010) A lower limit of 0.9 GHz; An upper limit of 1 GHz, 5. The continuous DAC device of claim 4, adapted to optimize illumination at frequencies between .times. ...

8. The vacuum pump (1020) adjusts the pressure in the resonant cavity (1015) to: A lower limit of 0.2 bar; An upper limit of 0.8 bar; 5. The continuous DAC device of claim 4, wherein the frequency is reduced to between .times. ...

9. 5. The continuous DAC device of claim 4, wherein the polyamine adsorbent is selected from the group consisting of linear polyethyleneimine (PEI), branched PEI, aziridine, diethylenetriamine, triethylenetetramine, diethylenetriaminoorganosilane, aminopropylorganosilane, linear PEI-functionalized cellulose acetate silicon dioxide adsorbent, branched PEI-functionalized cellulose acetate silicon dioxide adsorbent material, metal organic framework-incorporated linear PEI, metal organic framework-incorporated branched PEI, metal organic framework-incorporated amine, polyethylene MCM-41, and 3-trimethoxysilylpropyldiethylenetriamine SBA-15.

10. 1. A method for producing molecular carbon dioxide from a continuous direct air capture (DAC) device, comprising: introducing a laminar flow of air into a resonant cavity, said resonant cavity comprising: The entrance and The exit and a moving stage; a contactor; a polyamine sorbent associated with said contactor, wherein a plurality of carbon dioxide molecules present in the air become covalently bonded to said polyamine sorbent; and irradiating the polyamine adsorbent with microwave frequencies generated by a microwave generator, the microwave generator being adapted to select a microwave frequency to optimize breaking of bonds between the polyamine adsorbent and the plurality of carbon dioxide molecules to release the carbon dioxide molecules; A method comprising:

Images