CN120771683A - Direct air capturing CO by solid-phase rotating wheel concentration and liquid-phase chemical adsorption and desorption relay2System and process - Google Patents

Abstract

The invention discloses a direct air trapping CO ₂ system and a direct air trapping CO ₂ process with solid-phase rotating wheel concentration and liquid-phase chemical adsorption and desorption relay, wherein the direct air trapping CO ₂ system comprises a solid-phase CO ₂ concentration part and a liquid-phase CO ₂ adsorption and desorption part. Aiming at the process of directly capturing carbon dioxide in air, the invention realizes the rapid adsorption of low-concentration CO ₂ in the air through the honeycomb runner loaded with the solid-phase CO ₂ adsorbent, then the CO ₂ adsorbed by the runner is desorbed at a low temperature through hot nitrogen, after the concentration of CO ₂ in the nitrogen is increased to 0.5-10%, the nitrogen enters a filler absorption tower sprayed by a chemical absorption liquid, so that CO ₂ in the nitrogen is captured again, and the CO ₂ is captured and purified to recycle the rotary wheel to desorb the adsorbed CO ₂, thereby completing the adsorption and desorption cycle. The absorption liquid after absorbing CO ₂ enters a desorption tower for desorption, and the desorbed CO ₂ can obtain CO ₂ with purity of more than 99% after cooling and washing. The invention solves the problems of low efficiency, high energy consumption and unstable adsorbent of the traditional DAC trapping process, realizes the efficient trapping of direct air CO ₂ and obtains a high-purity CO ₂ product.

Description

Direct air trapping CO 2 system and process for solid-phase rotating wheel concentration and liquid-phase chemical adsorption and desorption relay

Technical Field

The invention belongs to the field of gas trapping, and particularly relates to a direct air CO ₂ trapping system and a direct air CO ₂ trapping process by solid-phase rotating wheel concentration and liquid-phase chemical adsorption and desorption relay.

Background

Direct air Capture CO ₂ (DIRECT AIR Capture, DAC) is one of the core paths of negative emission technologies, a key support technology to achieve the global carbon peak, carbon neutralization goals. The system breaks through the dependence of the traditional carbon capture technology on a large-scale fixed emission source, does not need to be coupled with industrial facilities or power plants, can directly separate CO ₂ from the atmosphere or a distributed emission source at any place, and remarkably improves the flexibility of a carbon capture scene. In addition, the DAC process avoids erosion of materials by high concentration acid gases (such as SO ₂、NO_x) and heavy metal pollutants in traditional flue gas treatment.

The mature liquid-phase chemical adsorption and desorption method is widely applied in the field of carbon capture due to the high adsorption rate, high adsorption capacity and relatively low desorption temperature. But also face significant limitations when applied to direct air CO ₂ capture. Because the concentration of CO ₂ in the atmosphere is extremely low, a large amount of air needs to be treated in order to capture enough CO ₂, which leads to high solvent volatilization loss and absorbent degradation, and in addition, the low CO ₂ loading rate of the absorption liquid greatly improves the CO ₂ analysis energy consumption, so that the capture cost of unit CO ₂ is greatly improved.

The existing mainstream direct air capture CO ₂ adopts a calcium hydroxide alkaline solution absorption route, the route depends on a high-temperature (> 900 ℃) thermal regeneration process, and severe desorption conditions not only cause a large amount of heat energy consumption, but also cause performance degradation and water resource loss of the hygroscopic absorbent. The temperature/pressure swing adsorption method based on the solid adsorbent has the same disadvantages, and is not only limited by the core challenges of airflow resistance pressure drop, insufficient desorption power, competitive adsorption of water molecules and the like of the adsorption unit, but also has the advantages that the system operation cost is increased jointly due to the power consumption of a fan, thermodynamic loss in a high-temperature/vacuum regeneration process, additional energy consumption for desorption of the water molecules and the problem of blockage of adsorption pore channels caused by condensation of water molecules, which are generated by air flowing through a compact adsorption layer. In addition, the current solid-phase absorbent trapping technology is difficult to obtain high-purity CO ₂, so that the direct recycling utilization of the rear-end CO ₂ is limited.

The CO ₂ trapping cost of the current commercial direct air trapping project is generally higher than 600 dollars/ton, and the large-scale application of the technology is obviously restricted by the high economic cost, so that the realization of cost reduction and efficiency improvement through brand-new process integration optimization and technology upgrading is urgently needed.

Disclosure of Invention

Aiming at the technical problems existing in the prior art, the invention provides a relay direct air CO ₂ trapping technology combining solid phase honeycomb runner adsorbent concentration and liquid phase chemical adsorbent adsorption and desorption, which utilizes the advantages of high flux of a solid adsorbent and high adsorption rate of low concentration CO ₂ and the advantages of high desorption rate of liquid phase absorption liquid CO ₂ and low energy consumption, firstly, realizes the rapid adsorption of low concentration CO ₂ in air through a honeycomb runner loaded with a solid phase CO ₂ adsorbent, then desorbs CO ₂ adsorbed by the runner through hot nitrogen at low temperature, so that the concentration of the desorbed CO ₂ is increased to 0.5% -10%, then 0.5% -10% of CO ₂ enters a liquid phase chemical adsorption spray tower for trapping, purified nitrogen returns to a desorption area of the honeycomb runner for recycling, and the liquid phase absorption liquid loaded with high CO ₂ enters the desorption tower, so that the chemically absorbed CO ₂ is released under the action of heat, and the CO ₂ gas with the concentration reaching more than 99% is obtained. The invention can realize low energy consumption, rapid and continuous trapping of the air CO ₂ by gradual relay trapping and concentration.

The invention adopts the following specific technical scheme:

a direct air CO ₂ capturing system with solid phase rotating wheel concentration and liquid phase chemical adsorption and desorption relay comprises a solid phase rotating wheel concentration system and a liquid phase chemical adsorption and desorption system;

The solid-phase runner concentration system comprises adsorption runner equipment, an air blower, a regenerated gas heater and an air inlet and outlet heat exchanger, wherein a honeycomb runner adsorbent is arranged in the adsorption runner equipment, comprises a honeycomb runner and a solid adsorbent loaded on the honeycomb runner, and comprises an adsorption zone, a cold blowing zone and a desorption zone, wherein the solid adsorbent in the adsorption runner equipment continuously circulates from the adsorption zone to the regeneration desorption zone and then to the cold blowing zone and then to the adsorption zone under the rotation of the adsorption runner equipment;

the air blower is connected with the adsorption area through a pipeline;

The circulating gas carrier gas is blown into the inlet of the cold blowing area after passing through the cold channel of the gas inlet and outlet heat exchanger, the outlet of the cold blowing area is connected with the inlet of the desorption area through a regenerated gas heater by a pipeline, the outlet of the desorption area discharges enriched gas rich in CO ₂, and the enriched gas is sent into the liquid-phase chemical absorption and desorption system to recover CO ₂ therein after passing through the hot channel of the gas inlet and outlet heat exchanger, so that the circulating gas carrier gas desorbed with CO ₂ is recycled, and a circulating loop of the circulating gas carrier gas is formed.

Further, the system of the invention also comprises an air filter, and the air conveyed by the air blower is blown into the adsorption zone after the solid impurities are filtered by the air filter.

The concentration part of the solid-phase CO ₂ is that air is pressurized by an air blower to contact with the honeycomb runner adsorbent in the adsorption zone, carbon dioxide is adsorbed by the solid adsorbent loaded on the honeycomb runner, and the tail gas from which the carbon dioxide is removed is discharged back to the atmosphere again. The honeycomb runner adsorbent loaded with carbon dioxide rotates to a desorption zone under the pushing of the runner, contacts with regenerated gas nitrogen heated by the regenerated gas heater, and the carbon dioxide is desorbed from the solid adsorbent under the action of heat, and the desorbed carbon dioxide is mixed with the nitrogen to form a concentrated gas. The honeycomb runner adsorbent is pushed by the runner to rotate to a cooling area after desorbing carbon dioxide and is cooled by cooling gas. And then rotated again to the adsorption zone, and the above process is repeated.

Further, the liquid-phase chemical adsorption and desorption system comprises a dense gas extraction fan, a spray filler absorption tower, a buffer tank, a rich liquid pump and a rich liquid regeneration system, wherein a hot channel outlet of the gas inlet and outlet heat exchanger is connected with a lower air inlet of the spray filler absorption tower through the dense gas extraction fan, a liquid absorbent is introduced into an upper liquid inlet of the spray filler absorption tower, a circulating gas carrier gas for desorbing CO ₂ is discharged from an air outlet of the top of the spray filler absorption tower and introduced into a cold channel of the gas heat exchanger, a CO ₂ -rich absorbent solution in the bottom of the spray filler absorption tower is firstly discharged into the buffer tank and then pumped out by the rich liquid pump to be fed into the rich liquid regeneration system for heating and desorbing CO ₂ therein, so that the liquid absorbent for desorbing CO ₂ is recycled, and a circulating loop of the liquid absorbent is formed.

Further, the rich liquid regeneration system comprises a lean and rich liquid heat exchanger, a lean liquid cooler, a desorption tower, a tower bottom pump, a flash tank, a lean liquid pump and a compressor, wherein an outlet of the rich liquid pump is connected with an upper liquid inlet of the desorption tower through a cold channel of the lean and rich liquid heat exchanger, a tower bottom reboiler is arranged at the lower part of the desorption tower, an outlet of the bottom of the desorption tower is connected with a middle inlet of the flash tank through the tower bottom pump, an air outlet at the top of the flash tank is connected with a lower air inlet of the desorption tower through the compressor through a pipeline, and negative pressure is kept in the flash tank under the operation effect of the compressor so as to facilitate flash evaporation, and a bottom liquid outlet of the flash tank is connected with an upper liquid inlet of the spray packing absorption tower through a heat channel of the lean liquid pump and the lean and rich liquid cooler.

The absorption and desorption part of the liquid-phase CO ₂ is that the nitrogen of the enriched gas is pressurized by an enriched gas blower and enters a spray filler absorption tower to be in reverse contact with a liquid-phase absorbent so as to finish carbon dioxide absorption. And the nitrogen with carbon dioxide removed is discharged from the top of the spray packing absorption tower and is returned to the adsorption rotating wheel equipment again to be used as regenerated gas. After the liquid phase absorbent is reversely contacted with the enriched gas, the CO ₂ -enriched absorption liquid is discharged into a lean-rich liquid heat exchanger through a rich liquid pump, enters the top of a desorption tower after heat exchange, is heated under the action of a tower bottom reboiler of the desorption tower, and CO ₂ is desorbed along with the temperature rise and is discharged from the top of the desorption tower. And (3) desorbing the CO ₂ -rich absorption liquid, reducing the load of CO ₂ therein to form a CO ₂ -lean absorption liquid, discharging the CO ₂ -lean absorption liquid into a lean-rich liquid heat exchanger through a lean liquid pump, performing heat exchange, entering the top of a spray packing absorption tower, and performing countercurrent contact with concentrated gas nitrogen again to repeat the process.

According to the scheme of the hot gas desorption solid-phase adsorbent, the problem of adsorption performance reduction caused by the blockage of the adsorbent pore canal caused by the traditional steam desorption is avoided, and the water removal and heating energy consumption of the adsorbent is reduced.

The air is concentrated through the solid-phase adsorption rotating wheel, the concentration of the concentrated gas is from 400ppm to 0.5% -10%, the concentration of the concentrated gas with the concentration of 0.5% -10% of carbon dioxide is captured through a liquid-phase chemical absorption method, and the high-purity CO ₂ with the concentration of more than 99% is desorbed from the desorption tower.

The regenerated gas nitrogen is discharged from the spray filler absorption tower and then enters the air inlet and outlet heat exchanger to exchange heat with the enriched gas, and then enters the rotating wheel cooling zone to exchange heat in the cooling zone, so that the load of the regenerated gas heater is greatly reduced.

The utility model provides a direct air entrapment CO ₂ technology of solid phase runner concentration and liquid phase chemisorption desorption relay, sets up honeycomb runner adsorbent in the absorption runner equipment, and honeycomb runner adsorbent includes honeycomb runner and load the solid adsorbent on honeycomb runner, and absorption runner equipment includes adsorption zone, cold blow district and desorption district, the method includes following steps:

S1, sucking and conveying ambient air by an air blower, removing solid impurities by an air filter, enabling the ambient air to enter an adsorption zone at room temperature and fully contact with a solid-phase adsorbent in the adsorption zone, and efficiently adsorbing CO ₂ in the air on the solid-phase adsorbent, and discharging purified gas after removing CO ₂ into the atmosphere;

S2, carrying out heat exchange on recycle gas carrier gas of desorption CO ₂ from a liquid-phase chemical adsorption and desorption system through a cold channel of an air inlet and outlet heat exchanger, blowing into the cold blowing area to cool solid phase adsorbent in the cold blowing area, heating to 180-220 ℃ through a recycle gas heater to form high-temperature recycle gas, introducing the recycle gas into the desorption area to carry out CO ₂ desorption on the solid phase adsorbent in the recycle gas, concentrating CO ₂ in the recycle gas to form concentrated gas, carrying out heat exchange on the concentrated gas through a hot channel of the air inlet and outlet heat exchanger, entering the liquid-phase chemical adsorption and desorption system to carry out chemical adsorption and desorption operation, removing CO ₂ in the concentrated gas through chemical adsorption, and then recycling the concentrated gas into the cold channel of the air inlet and outlet heat exchanger to form a recycle loop of CO ₂ concentration and desorption of the recycle gas carrier gas.

Further, the concentration of CO ₂ in the concentration gas extracted in the step S2 is 0.5% -10%, preferably 1% -5%, the temperature of the circulating gas carrier gas after heat exchange through the cold channel of the gas inlet and outlet heat exchanger is 60-75 ℃, and the temperature of the concentration gas after heat exchange through the hot channel of the gas inlet and outlet heat exchanger is 45-55 ℃.

Further, the operation of chemisorption and desorption comprises the steps of:

1) The concentrated gas enters the lower part of a spray filler absorption tower under the pressure rise of a concentrated gas fan, meanwhile, a liquid phase absorbent is introduced from the upper part of the spray filler absorption tower, the gas phase and the liquid phase are in countercurrent contact, CO ₂ in the concentrated gas is absorbed by the liquid phase absorbent, the circulating gas carrier gas after CO ₂ is removed is discharged from the top of the absorption tower, and the circulating gas carrier gas is reused;

2) The CO ₂ -rich absorption liquid at the bottom of the absorption tower is firstly discharged into a buffer tank, then pumped into a cold channel of a lean-rich liquid heat exchanger by a rich liquid pump for heat exchange and temperature rise, and then enters a desorption tower for heating and desorption, meanwhile, the absorption liquid at the bottom of the desorption tower is pumped into a flash tank by a bottom pump of the tower, the negative pressure in the flash tank is maintained under the action of a compressor, and the CO ₂ -rich desorption gas after flash evaporation is introduced into the lower part of the desorption tower again, and the desorption gas is discharged from the top of the desorption tower and then collected;

3) And (3) carrying out heat exchange and cooling on lean CO ₂ absorption liquid at the bottom of the flash tank through a heat channel from a lean liquid pump to a lean-rich liquid heat exchanger, then further cooling to 30-45 ℃ through a lean liquid cooler, and re-entering the upper part of the spray packing absorption tower to be in countercurrent contact with enriched gas so as to complete absorption and desorption circulation.

Further, the concentration of CO ₂ in the circulating gas carrier gas discharged from the top of the absorption tower in the step 1) is less than 0.5%, the CO ₂ -rich absorption liquid in the step 2) is heated to 75-85 ℃ through heat exchange of a lean-rich liquid heat exchanger and then is sent into a desorption tower for heating and desorption, the temperature of heating and desorption is 90-100 ℃, and the CO ₂ -lean absorption liquid in the step 3) is cooled to 50-60 ℃ through heat exchange of the lean-rich liquid heat exchanger.

Further, the loading capacity of the solid adsorbent on the honeycomb runner is 20% -50%, and the solid adsorbent is one of amino functionalized solid phase adsorbents such as amino functionalized alkaline high polymer porous resin, amino functionalized ionic liquid porous materials and the like. Or the solid adsorbent is one or more of non-amino functionalized solid adsorbents such as zeolite, active carbon, metal Organic Frameworks (MOFs), mesoporous silica, carbon nanomaterial and the like.

Further, the liquid phase absorbent is one or more of organic amine compounds such as monoethanolamine, diethanolamine, methyldiethanolamine, piperazine, 2-amino-2-methyl-1-propanol, triethylene tetramine and the like. Or the liquid phase absorbent is amino functional ionic liquid with the effective component of quaternary ammonium nitrogen heterocyclic ionic liquid and the like.

Compared with the prior art, the invention has the beneficial effects that:

1) The honeycomb solid-phase rotating wheel concentration replaces the traditional solid-phase adsorption, and the adsorption and the thermal regeneration of CO ₂ are simultaneously carried out in different areas, thereby replacing the traditional intermittent solid-phase adsorption method. The characteristic of continuous operation enables the CO ₂ capturing process to be carried out uninterruptedly, and on the premise of keeping high-flux absorption of solid-phase air, the continuous operation greatly increases the efficiency of capturing and concentrating air CO ₂.

2) The low-temperature desorption of the desorption tower by the liquid-phase chemical absorption method replaces the direct steam desorption of solid-phase desorption, avoids the defect that the efficiency of the solid adsorbent is greatly reduced due to the blockage of the pore channels by steam condensate, simultaneously plays the advantages of fast liquid-phase absorption and desorption circulation, high trapping efficiency and high purity of desorption gas, simultaneously reduces the steam consumption, greatly reduces the latent heat of steam condensation, reduces the cycle heating sensible heat, and reduces the comprehensive energy consumption by more than 60 percent compared with the existing direct trapping method of solid-phase air.

3) The novel process of CO ₂ concentration combined with liquid phase chemical absorption relay trapping by adopting the solid phase rotating wheel can gradually increase the concentration of CO ₂ in the air, exert the respective advantages of the solid phase trapping technology and the liquid phase trapping technology, reduce the energy consumption and the cost of air trapping CO ₂, and greatly expand the application scene and the flexibility of carbon trapping.

4) The nitrogen is used as the carrier of the regenerated gas and the enriched gas, so that the solid phase adsorption and the liquid phase absorption of nitrogen are connected in series in an internal circulation manner, the contact of the solid phase adsorbent and the liquid phase adsorbent with oxygen at high temperature is avoided, the oxidative degradation rate of the adsorbent and the adsorbent is reduced, and the loss of the adsorbent is reduced.

5) By adopting the nitrogen circulation technology, nitrogen is fully utilized, volatilization of liquid phase absorption liquid can be greatly reduced, and pollution to the atmosphere caused by volatilization of the absorption liquid in carbon capture is reduced.

Drawings

FIG. 1 is a schematic diagram of a direct air carbon dioxide capturing system with solid phase rotating wheel concentration and liquid phase chemical adsorption and desorption relay;

FIG. 2 is a block diagram illustrating the flow of the direct air carbon dioxide capture process of the present invention with solid phase rotor concentration and liquid phase chemisorption and desorption relay;

In the figure, 1, an air blower, 2, an air filter, 3, an adsorption zone, 4, a desorption zone, 5, a regeneration gas heater, 6, an inlet and outlet heat exchanger, 7, a cooling zone, 8, a dense air blower, 9, a spray packing absorption tower, 10, a buffer tank, 11, a rich liquid pump, 12, a lean and rich liquid heat exchanger, 13, a lean liquid cooler, 14, a desorption tower, 15, a tower bottom pump, 16, a flash tank, 17, a lean liquid pump, 18, a compressor, 19 and an amine escape control tower.

Detailed Description

The invention will be further illustrated with reference to specific examples, but the scope of the invention is not limited thereto.

Examples:

As shown in figures 1-2, the direct air CO ₂ capturing system with solid phase rotating wheel concentration and liquid phase chemical adsorption and desorption relay comprises a solid phase rotating wheel concentration system and a liquid phase chemical adsorption and desorption system.

The solid-phase runner concentration system comprises adsorption runner equipment, an air blower 1, an air filter 2, a regenerated gas heater 5 and an air inlet and outlet heat exchanger 6, wherein a honeycomb runner is arranged in the adsorption runner equipment, and a solid adsorbent is loaded on the honeycomb runner. The adsorption runner device comprises an adsorption zone 3, a cold blowing zone 7 and a desorption zone 4, and the solid phase adsorbent in the adsorption runner device continuously circulates from the adsorption zone to the regeneration desorption zone, then to the cold blowing zone and then to the adsorption zone under the rotation of the adsorption runner device.

The air blower 1 is connected with the adsorption zone 3 through an air filter 2 by a pipeline, and air conveyed by the air blower 1 is blown into the adsorption zone 3 after solid impurities are filtered by the air filter 2.

The circulating gas carrier gas is blown into the inlet of the cold blowing zone 7 after passing through the cold channel of the gas inlet and outlet heat exchanger 6, the outlet of the cold blowing zone 7 is connected with the inlet of the desorption zone 4 through a pipeline by the regenerated gas heater 5, the outlet of the desorption zone 4 discharges the enriched gas rich in CO ₂, and the enriched gas is sent into the liquid-phase chemical absorption and desorption system to recycle the CO ₂ therein after passing through the hot channel of the gas inlet and outlet heat exchanger 6, so that the circulating gas carrier gas for desorbing CO ₂ is recycled, and a circulating loop of the circulating gas carrier gas is formed.

The liquid-phase chemical adsorption and desorption system comprises a dense air blower 8, a spray filler absorption tower 9, a buffer tank 10, a rich liquid pump 11 and a rich liquid regeneration system, wherein a hot channel outlet of the air inlet and outlet heat exchanger 6 is connected with a lower air inlet of the spray filler absorption tower 9 through the dense air blower 8, a liquid absorbent is introduced into an upper liquid inlet of the spray filler absorption tower 9, a circulating gas carrier gas for desorbing CO ₂ is discharged from an air outlet of the top of the spray filler absorption tower 9 and introduced into a cold channel of the air heat exchanger 6, a rich CO ₂ absorbent solution in the bottom of the spray filler absorption tower 9 is firstly discharged into the buffer tank 10 and then pumped into the rich liquid regeneration system through the rich liquid pump 11 to carry out heating desorption of CO ₂ therein, so that a liquid absorbent for desorbing CO ₂ is recycled, and a circulating loop of the liquid absorbent is formed.

The rich liquid regeneration system comprises a lean-rich liquid heat exchanger 12, a lean liquid cooler 13, a desorption tower 14, a tower bottom pump 15, a flash tank 16, a lean liquid pump 17 and a compressor 18, wherein an outlet of the rich liquid pump 11 is connected with an upper liquid inlet of the desorption tower 14 through a cold channel of the lean-rich liquid heat exchanger 12, a heater is arranged in the lower part of the desorption tower 14, an outlet at the bottom of the desorption tower 14 is connected with a middle inlet of the flash tank 16 through the tower bottom pump 15, an outlet at the top of the flash tank 16 is connected with a lower air inlet of the desorption tower 14 through the compressor 18, a negative pressure is kept in the flash tank 16 under the operation effect of the compressor 18 so as to promote desorption, and a bottom liquid outlet of the flash tank 16 is connected with an upper liquid inlet of the spray filler absorption tower 9 through the lean liquid pump 17, a hot channel of the lean-rich liquid heat exchanger 12 and the lean liquid cooler 13.

Referring to fig. 1, the top gas outlet of the desorption column 14 is further connected with an amine escape control column 19 through a pipeline, and the amine escape control column 19 is a condensing device of the absorbent component. The stripping gas is discharged from the top of the desorption tower 14, the temperature is reduced through the amine escape control tower 19, liquid drops of the absorbent component are condensed and refluxed, and uncondensed pure CO ₂ is sent to a storage tank for sealing.

Example 1:

The liquid absorbent in the embodiment 1 of the invention adopts an ionic liquid water-free absorbent, the preparation process is feasible, imidazole (Im) and an equimolar amount of tetramethylammonium hydroxide ([ N1111] [ OH ]) solution are stirred for 24 hours at 60 ℃, OH-ions provided by tetramethylammonium hydroxide and imidazole undergo a proton transfer reaction to generate imidazolium anions ([ Im ] -), and the imidazolium anions ([ Im ] -) and tetramethylammonium hydroxide cations ([ N1111] ⁺) form the amino functional ionic liquid water-free absorbent with the structure of [ N1111] [ Im ].

The honeycomb runner base wheel is a porous honeycomb corrugated medium, is made of ceramic fiber, and is purchased from a tin-free desert dehumidification equipment factory. The solid adsorbent in the embodiment 1 of the invention is an amino functional resin adsorbent, the functional resin is IRA-900 resin, the functional resin is derived from DuPont of U.S.A., the functional resin is an anion exchange resin with quaternary ammonium groups [ -N (CH ₃)₃ OH ] on a styrene-divinylbenzene copolymer with a macroporous structure, the model is IRA-900. The step of loading the solid adsorbent on a honeycomb runner is as follows:

S1, filling IRA-900 resin into a chromatographic column, and using column chromatography, and using an excessive NaOH/ethanol solution with the mass fraction of 5wt% to flow through the chromatographic column for ion exchange to convert the resin into oxyhydrogen resin;

S2, eluting the resin in the chromatographic column by using an excessive imidazole/ethanol solution with the mass fraction of 5wt%, wherein the aim is to introduce an amino group on the resin in an ion exchange mode, and the aim of the excessive imidazole/ethanol solution is to completely exchange the ions of the imidazole and the resin;

s3, repeatedly washing the resin obtained in the step S2 by using ethanol, then drying the resin in vacuum at 80 ℃ for 24 hours, and grinding the adsorbent resin into fine powder of 1-3 nm;

s4, mixing the fine powder obtained in the step S3 with water and inorganic binder acidic silica sol (the mass fraction is 30%) in a mass ratio of 50%/45%/5% to obtain adsorbent slurry;

S5, soaking the honeycomb runner base wheel in the adsorbent slurry obtained in the step S4, then lifting the honeycomb runner base wheel out of the slurry, naturally dropping the non-adhered adsorbent slurry, then soaking the honeycomb runner base wheel in the adsorbent slurry, pouring the honeycomb runner base wheel in the adsorbent slurry for a plurality of times until the mass of the adsorbent slurry loaded on the honeycomb runner base wheel reaches 70% of the mass of the honeycomb runner base wheel, drying by hot air at 120 ℃ to promote gelation, removing water and binder, improving the bonding strength to be more than or equal to 5.0N/cm, and fully exposing pore channels of the material, so as to prepare the solid-phase runner loaded with the amino functional resin, namely the honeycomb runner adsorbent.

A direct air trapping CO ₂ process (see figure 2) with solid phase rotating wheel concentration and liquid phase chemical adsorption and desorption relay, which comprises the following steps:

1) The CO ₂ content in the air is 400ppm, the air flow rate extracted by the air blower 1 is 1000m ³/h, impurities such as dust particles and the like are removed through an air filter, and then the air is blown into an adsorption zone 3 of the adsorption rotating wheel equipment, fully contacts with an amino functional resin adsorbent loaded on a honeycomb rotating wheel, CO ₂ is captured by the amino functional resin adsorbent at 25 ℃ and stored in a pore canal of the adsorbent, and the carbon dioxide load of the amino functional resin adsorbent is increased from 0.3mol/kg to 1.3mol/kg of saturated absorption load.

The concentration of the deacidified purified gas CO ₂ discharged from the adsorption zone 3 was 40ppm, and the purified gas was discharged into the atmosphere, and the absorption efficiency of CO ₂ was 90%.

2) After the amino functional resin adsorbent on the honeycomb runner in the adsorption zone 3 adsorbs CO ₂, the adsorbent rotates to the desorption zone 4 along with the runner. And introducing 200 ℃ regenerated gas from the regenerated gas heater 5 into the desorption zone 4 to purge the adsorbent in the regenerated gas heater, removing CO ₂ from the solid-phase adsorbent, performing heat exchange and desorption combined with heat absorption, swelling the regenerated gas at 80 ℃, and raising the concentration of mixed CO ₂ to 2% to form a concentrated gas, wherein the concentration of CO ₂ is 50 times of that of the concentrated gas. Then the temperature is reduced to 50 ℃ after heat exchange is carried out through a heat channel of the air outlet heat exchanger 6, and the air is introduced into a chemical absorption desorption part.

In the solid-phase rotating wheel concentration process, the rotation of the rotating wheel enables three links of solid-phase absorbent adsorption, desorption and cooling to be carried out simultaneously, so that the continuity of the concentration process is ensured. And the concentration of CO ₂ is improved by concentrating high-flux air, so that the high-efficiency liquid-phase chemical absorption method can be applied, the reaction time is greatly shortened, the circulating load is improved, and the regeneration energy consumption of the chemical absorption method is reduced.

3) The 50 ℃ enriched gas enters the lower part of the spray filler absorption tower 9 at the flow rate of 170m ³/h under the pressure increase of the enriched gas fan 8, meanwhile, 40 ℃ liquid phase absorbent is introduced from the upper part of the spray filler absorption tower 9, the spraying amount of the liquid phase absorbent is 500L/h, and the liquid phase absorbent and the enriched gas are in countercurrent contact in the spray filler absorption tower 9, and the two are subjected to full heat exchange. CO ₂ in the concentrated gas is absorbed by the liquid phase absorbent, and after purification, the circulating gas carrier gas is formed and discharged from the top of the spray packing absorption tower 9, the concentration of CO ₂ in the discharged circulating gas carrier gas is 0.2%, and the absorption efficiency of the absorption tower is 90%. CO ₂ load of 1.5mol/kg of ionic liquid rich liquid at 50 ℃ is formed at the bottom of the spray packing absorption tower 9, is buffered by the buffer tank 10, and is pumped to a cold channel of the lean-rich liquid heat exchanger 12 by the rich liquid pump 11 to perform heat exchange and temperature rise to 85 ℃ to enter the desorption tower 14.

4) Under the action of a tower bottom reboiler of the desorption tower 14, the temperature in the tower of the desorption tower 14 is increased to 95 ℃, CO ₂ is removed from the ionic liquid rich liquid, meanwhile, the tower bottom absorption liquid of the desorption tower 14 is pumped into a flash tank 16 through a tower bottom pump 15, under the action of a compressor 18, the flash tank 16 forms 20kpa negative pressure, the tower bottom absorption liquid is further desorbed in the flash tank, and the lean liquid with the CO ₂ load of 0.5mol/kg is formed after desorption.

The desorption gas is discharged from the top of the desorption tower 14, the temperature is reduced through the amine escape control tower 19, liquid drops of the absorbent component are condensed and reflux, and pure CO ₂ is sent into a storage tank for sealing.

The lean solution with the CO ₂ load of 0.5mol/kg at the bottom of the flash tank 16 is pumped to a hot channel of the lean-rich solution heat exchanger 12 through the lean solution pump 17 to exchange heat and cool to 55 ℃, then is further cooled to 40 ℃ through the lean solution cooler 13, and enters the top of the spray packing absorption tower 9 again to be in countercurrent contact with the enriched gas, so that the absorption and desorption cycle is completed. The ionic liquid low-water absorbent is adopted, and the desorption can be carried out at a low temperature of 90 ℃, so that the desorption energy consumption is greatly reduced.

5) After the concentrated gas is in countercurrent contact with the liquid absorbent in the spray filler absorption tower 9, the circulating gas carrier gas is discharged from the top of the spray filler absorption tower 9 and is used as cooling gas of the honeycomb runner absorbent for recycling. After the circulating gas firstly exchanges heat through a cold channel of the air inlet and outlet heat exchanger 6, the temperature is raised to 70 ℃, then the circulating gas is blown into the cold blowing area 7 to cool the solid phase adsorbent in the cold blowing area, meanwhile, the circulating gas is further raised in temperature, and is heated to 200 ℃ through the gas heater 5, so that the regenerated gas enters the solid phase runner regeneration area to desorb the amino functionalized resin, the regenerated gas is concentrated to form concentrated gas, and the concentrated gas is removed from the liquid phase for absorption again. The whole solid phase desorption area is in the circulation of the circulating gas and nitrogen, so that the problem of amine escape which is generally difficult to treat by the traditional chemical absorption method is greatly reduced, and the problem of degradation of the solid phase adsorbent is also reduced. And through the heat exchange network, the heat supply of the system is greatly reduced, and the high energy consumption of pure solid phase air trapping is realized.

According to the experimental procedure of example 1 of the present invention, when the recycle gas carrier gas was operated with nitrogen gas under the condition of stable operation for 12 hours, no attenuation was detected in the adsorption or absorption performance of the solid phase adsorbent (i.e., amine-based functionalized resin adsorbent carried by the honeycomb runner) and the liquid phase adsorbent (i.e., ionic liquid water-free adsorbent) on CO ₂, wherein the adsorption or absorption performance is based on the trapping performance on CO ₂. For example, the adsorption performance of the solid phase adsorbent on CO ₂ is evaluated as the concentration of CO ₂ in the enriched gas over time. The absorption performance of the liquid phase absorbent on CO ₂ is evaluated as the absorption efficiency of the spray packing absorption tower 9 on CO ₂.

However, according to the experimental procedure of example 1 of the present invention, the adsorption performance of the solid phase adsorbent was attenuated by about 20% to 25% and the adsorption performance of the liquid phase adsorbent was attenuated by about 2% to 5% when the recycle gas carrier gas was operated with oxygen under the stable operation for 200 hours.

Therefore, the nitrogen circulation can greatly inhibit the oxidative degradation rate of the solid-phase adsorbent and the liquid-phase adsorbent, and improve the service lives of the adsorbent and the adsorbent.

In addition, the experimental performance of CO ₂ capturing and desorbing was compared with the experimental data disclosed in prior document "K.Z.House,A.C.Baclig,M.Ranjan,E.A.van Nierop,J.Wilcox,&H.J.Herzog,Economic and energetic analysis ofcapturing CO2 from ambient air,Proc.Natl.Acad.Sci.U.S.A.108(51)20428-20433" under the process conditions of example 1 of the present invention, and the process effects of both of them directly capturing CO ₂ in air and desorbing CO ₂ are shown in table 1.

TABLE 1 comparison of Process effects of direct air capture CO ₂ -Desorption CO ₂

In table 1, total energy consumption and integrated cost refer to total energy consumption for capturing and desorbing and recovering 1 ton of CO ₂ and total cost for capturing and desorbing and recovering 1 ton of CO ₂, respectively.

The calculation formula of the CO ₂ trapping efficiency is shown in formula (1):

Is the carbon dioxide capturing rate in units;

Q _out, the outlet air flow of the DAC trapping system under the standard state is m ³/h;

C _m,out, capturing the mass concentration of carbon dioxide in the air at the outlet of the system under the standard state, wherein the unit is g/m ³;

Q _in, the air flow rate of the DAC trapping system under the standard state is m ³/h;

And C _m,in, the mass concentration of carbon dioxide at the inlet air of the DAC trapping system under the standard state is expressed as g/m ³.

The calculation formula of the total energy consumption of the direct air trapping and the heating desorption regeneration of the CO ₂ is shown as the formula (2):

SE=SE_r+SE_e (2)

SE _e is used for capturing 1 ton of CO ₂, the unit is kW.h/tCO ₂, and specifically in the invention, the energy consumption of SE _e mainly depends on the electric consumption of the air blower 1, the regeneration gas heater 5, the enriched gas blower 8, the lean solution cooler 13 and the lean solution pump 17.

SE _r after 1 ton of CO ₂ is captured by the DAC capturing system, the captured CO ₂ is heated, desorbed and the consumed energy is recovered, and the unit is GJ/tCO ₂. In particular, in the present invention, the energy consumption of SE _r is mainly determined by the electricity consumption of the rich liquid pump 11, the reboiler at the bottom of the desorption column 14, the bottom pump 15, the compressor 18, and the amine escape control column 19.

SE is the total heat consumption of the trapping system per unit carbon dioxide, and is the total energy consumed by trapping and desorbing and recycling 1 ton of carbon dioxide, and the unit is GJ/tCO ₂.

In addition, the liquid phase absorption method in the prior art is utilized for directly capturing air, and because theoretical energy consumption is too high, no implementation case exists, and according to theoretical data estimation, the total energy consumed by capturing and desorbing and recycling 1 ton of carbon dioxide reaches more than 30GJ/t, and the total cost of capturing and desorbing and recycling 1 ton of CO ₂ reaches more than 600$/t.

What has been described in this specification is merely an enumeration of possible forms of implementation for the inventive concept and may not be considered limiting of the scope of the present invention to the specific forms set forth in the examples.

Claims (10)

1. A direct air CO ₂ capturing system with solid phase rotating wheel concentration and liquid phase chemical absorption and desorption relay is characterized by comprising a solid phase rotating wheel concentration system and a liquid phase chemical absorption and desorption system;

The solid-phase rotating wheel concentration system comprises an adsorption rotating wheel device, an air blower (1), a regeneration gas heater (5) and a gas inlet and outlet heat exchanger (6), wherein a honeycomb rotating wheel adsorbent is arranged in the adsorption rotating wheel device, comprises a honeycomb rotating wheel and a solid adsorbent loaded on the honeycomb rotating wheel, and comprises an adsorption zone (3), a cold blowing zone (7) and a desorption zone (4), wherein the solid adsorbent in the adsorption rotating wheel device continuously circulates from the adsorption zone to the regeneration desorption zone, then to the cold blowing zone and then to the adsorption zone under the rotation of the adsorption rotating wheel device;

The air blower (1) is connected with the adsorption area (3) through a pipeline;

the circulating gas carrier gas is blown into the inlet of the cold blowing area (7) after passing through the cold channel of the air inlet and outlet heat exchanger (6), the outlet of the cold blowing area (7) is connected with the inlet of the desorption area (4) through a regenerated gas heater (5) by a pipeline, the outlet of the desorption area (4) discharges the enriched gas rich in CO ₂, and the enriched gas is sent into the liquid-phase chemical absorption and desorption system to recover the CO ₂ therein after passing through the hot channel of the air inlet and outlet heat exchanger (6), so that the circulating gas carrier gas of the desorbed CO ₂ is recycled, and a circulating loop of the circulating gas carrier gas is formed.

2. A direct air carbon dioxide capturing system with solid phase rotating wheel concentration and liquid phase chemical absorption and desorption relay as claimed in claim 1, further comprising an air filter (2), wherein the air conveyed by the air blower (1) is blown into the adsorption zone (3) after the solid impurities are filtered by the air filter (2).

3. The direct air carbon dioxide capturing system with solid-phase rotating wheel concentration and liquid-phase chemical adsorption and desorption relay as claimed in claim 1, wherein the liquid-phase chemical adsorption and desorption system comprises a dense air blower (8), a spray filler absorption tower (9), a buffer tank (10), a rich liquid pump (11) and a rich liquid regeneration system, a hot channel outlet of the gas inlet and outlet heat exchanger (6) is connected with a lower air inlet of the spray filler absorption tower (9) through the dense air blower (8), a liquid absorbent is introduced into an upper liquid inlet of the spray filler absorption tower (9), a circulating gas carrier gas for desorbing CO ₂ is discharged from an air outlet of the top of the spray filler absorption tower (9) and introduced into a cold channel of the gas heat exchanger (6), a CO-rich ₂ absorbent solution in the bottom of the spray filler absorption tower (9) is firstly discharged into the buffer tank (10), and then pumped into the rich liquid regeneration system through the rich liquid pump (11) to carry out heating desorption of CO ₂, so that the liquid absorbent of the CO ₂ is recovered, and a circulating loop of the liquid absorbent is formed.

4. A solid-phase runner concentration and liquid-phase chemical adsorption-desorption relay direct air carbon dioxide capturing system as claimed in claim 3, wherein the rich liquid regeneration system comprises a lean-rich liquid heat exchanger (12), a lean liquid cooler (13), a desorption tower (14), a tower bottom pump (15), a flash tank (16), a lean liquid pump (17) and a compressor (18), an outlet of the rich liquid pump (11) is connected with an upper liquid inlet of the desorption tower (14) through a cold channel of the lean-rich liquid heat exchanger (12) through a pipeline, a tower bottom reboiler is arranged at the lower part of the desorption tower (14), a bottom outlet of the desorption tower (14) is connected with a middle inlet of the flash tank (16) through the tower bottom pump (15), a top air outlet of the flash tank (16) is connected with a lower air inlet of the desorption tower (14) through the compressor (18), a negative pressure is kept in the flash tank (16) under the operation of the compressor (18) so as to facilitate flash evaporation, and a bottom liquid outlet of the flash tank (16) is connected with a filler inlet of the lean liquid cooler (13) through a heat channel of the lean liquid pump (17) and the rich liquid heat exchanger (12) through a pipeline.

5. The direct air carbon dioxide capturing process of solid-phase runner concentration and liquid-phase chemical adsorption and desorption relay is characterized in that a honeycomb runner adsorbent is arranged in adsorption runner equipment, the honeycomb runner adsorbent comprises a honeycomb runner and a solid adsorbent loaded on the honeycomb runner, the adsorption runner equipment comprises an adsorption zone (3), a cold blowing zone (7) and a desorption zone (4), and the method comprises the following steps:

The method comprises the steps that S1, an air blower (1) pumps and conveys ambient air, solid impurities are removed through an air filter (2), the ambient air enters an adsorption zone (3) at room temperature and fully contacts with solid-phase adsorbents in the adsorption zone, CO ₂ in the air is efficiently adsorbed on the solid-phase adsorbents, purified air after CO ₂ is removed is discharged into the atmosphere, and the solid-phase adsorbents in the adsorption zone (3) after CO ₂ are adsorbed rotate along with a rotating wheel to a desorption zone (4);

S2, carrying out heat exchange on circulating gas carrier gas for desorbing CO ₂ from a liquid-phase chemical adsorption and desorption system through a cold channel of an air inlet and outlet heat exchanger (6), blowing the circulating gas carrier gas into a cold blowing area (7) to cool solid-phase adsorbent in the cold blowing area, heating the circulating gas carrier gas to 180-220 ℃ through a regenerated gas heater (5) to form high-temperature regenerated gas, introducing the regenerated gas into a desorption area (4) to desorb CO ₂ on the solid-phase adsorbent in the regenerated gas, concentrating CO ₂ in the regenerated gas to form concentrated gas, carrying out heat exchange on the concentrated gas flow through a hot channel of the air inlet and outlet heat exchanger (6), and then entering the liquid-phase chemical adsorption and desorption system to carry out chemical adsorption and desorption operation, wherein CO ₂ in the concentrated gas is subjected to chemical adsorption and desorption operation to reform the circulating gas carrier gas, and then is reused in the cold channel of the air inlet and outlet heat exchanger (6) to form a circulating loop for concentrating and desorbing the CO ₂ of the circulating gas carrier gas.

6. The process according to claim 5, wherein the circulating gas carrier gas is N ₂, the concentration of CO ₂ of the enriched gas in step S2 is 0.5% -10%, preferably 1% -5%, the temperature of the circulating gas carrier gas after heat exchange through the cold channel of the gas inlet/outlet heat exchanger (6) is 60-75 ℃, and the temperature of the enriched gas after heat exchange through the hot channel of the gas inlet/outlet heat exchanger (6) is 45-55 ℃.

7. The process of claim 5, wherein the operations of chemisorption and desorption comprise the steps of:

1) The concentrated gas enters the lower part of a spraying filler absorption tower (9) under the pressure rise of a concentrated gas fan (8), meanwhile, a liquid phase absorbent is introduced from the upper part of the spraying filler absorption tower (9), the gas phase and the liquid phase are in countercurrent contact, CO ₂ in the concentrated gas is absorbed by the liquid phase absorbent, the circulating gas carrier gas after removing CO ₂ is discharged from the top of the absorption tower (9), and the circulating gas carrier gas is reused;

2) The CO ₂ -rich absorption liquid at the bottom of the absorption tower (9) is firstly discharged into a buffer tank (10), then pumped out by a rich liquid pump (11) to be sent into a cold channel of a lean and rich liquid heat exchanger (12) for heat exchange and temperature rise, and then enters a desorption tower (14) for heating and desorption, meanwhile, the absorption liquid at the bottom of the desorption tower (14) is pumped into a flash tank (16) through a bottom pump (15), the negative pressure in the flash tank (16) is maintained under the action of a compressor (18), the CO ₂ -rich desorption gas after flash evaporation is introduced into the lower part of the desorption tower (14) again, and the desorption gas is discharged from the top of the desorption tower (14) and then collected;

3) And (3) carrying out heat exchange and cooling on lean CO ₂ absorption liquid at the bottom of the flash tank (16) through a heat channel from a lean liquid pump (17) to a lean-rich liquid heat exchanger (12), then further cooling to 30-45 ℃ through a lean liquid cooler (13), and re-entering the upper part of a spray packing absorption tower (9) to be in countercurrent contact with the enriched gas to complete absorption and desorption circulation.

8. The process of claim 5, wherein the concentration of CO ₂ in the circulating gas carrier gas discharged from the top of the absorption tower (9) in the step 1) is less than 0.5%, the temperature of the absorption liquid rich in CO ₂ in the step 2) is raised to 75-85 ℃ through heat exchange of a lean-rich liquid heat exchanger (12), the absorption liquid is sent into a desorption tower (14) for heating and desorption, the temperature of the heating and desorption is 90-100 ℃, and the temperature of the absorption liquid lean in CO ₂ in the step 3) is lowered to 50-60 ℃ through heat exchange of the lean-rich liquid heat exchanger (12).

9. The process of claim 5, wherein the loading of the solid adsorbent on the honeycomb runner is 20% -50%, and the solid adsorbent is one of an amine-functionalized alkaline high molecular porous resin, an amine-functionalized ionic liquid porous material, zeolite, activated carbon, a metal organic framework, mesoporous silica, and a carbon nanomaterial.

10. The process of claim 5, wherein the active ingredient of the liquid phase absorbent is an organic amine compound or an amino-functionalized ionic liquid, the organic amine compound is one or more of monoethanolamine, diethanolamine, methyldiethanolamine, piperazine, 2-amino-2-methyl-1-propanol and triethylenetetramine, and the amino-functionalized ionic liquid is a quaternary ammonium nitrogen heterocyclic ionic liquid.