TWI405606B - A carbon dioxide adsorption system - Google Patents

Abstract

The invention discloses a kind of carbon dioxide absorption system, which can effectively absorb the carbon dioxide in a standby-processing waste gas by using a humidity-modulating device and an absorption device containing absorption material. The absorption material in the absorption device can be reused accordingly by shedding the carbon dioxide in the absorption material via desorption function, therefore, it can effectively reduce the purifying cost of carbon dioxide and at the same time achieve the effect of resources reuse and attain the goal of energy conservation and carbon reduction.

Description

Carbon dioxide adsorption system

The present invention relates to a carbon dioxide adsorption apparatus, and more particularly to an apparatus which can effectively remove carbon dioxide from exhaust gas from a power plant or a factory.

As the greenhouse effect became more and more obvious, the Kyoto Protocol came into force. At the same time, Carbon dioxide Capture and Storage (CCS) was also evaluated as one of the feasible methods by the UN's IPCC in 2005. enumerate. These include the most commonly discussed wet absorption MEA method, dry adsorption method, and thin film method.

After searching for patents related to carbon dioxide adsorption, the Republic of China patent has “method of adsorbing carbon dioxide from a carbon dioxide-containing gas stream, carbon dioxide adsorbent and its manufacturing method (certificate number: 176857)”, and “removal of carbon dioxide from gas flow (announcement) No.: 592788)" and "method and equipment for removing water, carbon dioxide and nitrous oxide from air feed stream, air separation method and equipment (publication number: 455505)", etc., among these three patents The scope of application or the materials used are different from this patent.

In addition, in the Chinese patent, there are "method of preparing carbon dioxide adsorbent by using calcium oxide and rice husk ash (200810156154.4)", "high-temperature carbon dioxide adsorbent containing silicon-sodium-sodium sulphate and a preparation method of the adsorbent, and hydrogen production. The application in the process (application number: 200510060911.4) and "solid carbon dioxide adsorbent and its preparation method (application number: 95119387.2)", the materials used in the three patents are not the same as this patent. The "carbon dioxide recovery unit (application number: 200720034221.6)" is a device that is used in industrial applications such as beer industry equipment, and is not used in power plants or industrial waste gas.

The related patents in the U.S. patent are Gray et al. (2003) "AMINE ENRICHED SOLID SORBENTS FOR CARBON DIOXIDE CAPTURE (Pat. #: US 6,547,854 B1)", which is to treat the adsorbent substrate by acid and alkali treatment, and then The metal oxide, the amine salt and the like are treated to achieve the purpose of functionalization. Although the substrate includes a carbon nanotube and a molecular sieve, the carbon dioxide adsorption amount obtained in the method is low, and the highest is only 0.17 mmole/g (7.48). Mg/g), and this patent only discloses the adsorbent itself and is not further combined with the device.

The "Carbon dioxide capture process with regenerable sobents (Pat. #: US 6,387,337 B1)" by Pennline and Haffman (2002) uses alkali metals or alkaline earth metals as adsorbents. A double-bed reactor reacts with carbon dioxide greenhouse gases, and the adsorbents and devices used are not the same as those disclosed in this case.

In addition, the patent "HIGH CAPACITY IMMOBILIZED AMINE SORBENTS (Pat. #: US 7,288,136 B1)" by Gray et al. (2007) uses a secondary amine as a modifier, and the adsorption substrate used therein can be Nai. The carbon nanotube or molecular sieve, and the scope of its patent disclosure only covers the adsorbent itself, and the optimum adsorption amount of the adsorbent is also lower than that of the device disclosed in the patent, and thus is different from the disclosure of the present invention.

Other relevant literature includes "Comparative study of CO ₂ capture by carbon nanotubes, activated carbon and zeolites (Energy & Fuels, 22, 3050-3056)" by Lu et al. (2008). After treatment of CNTs, activated carbon and zeolite by APTS , showing that CNT (APTS) has the best carbon dioxide adsorption capacity. Su et al. (2009) "CO ₂ Capture from flue gas via multiwalled carbon nanotubes (Science of the Total Environment, 407, 3017-3023)". After the CNTs were modified by APTS, EDA and PEI, the adsorption amount of CO ₂ modified by APTS was the best, and the adsorption amount was better at low temperature (20-60 ° C), but it was not for moisture content. The effects were explored and not combined with the adsorption unit.

Therefore, in the conventional literature or patent, the relevant research results of the effective combination of the adsorbent and the adsorption experimental device have not been found, and the carbon dioxide can be continuously and rapidly adsorbed at low temperature adsorption (<80 ° C), and the adsorbent material is not easily deteriorated. efficacy. Therefore, the present invention provides a carbon dioxide adsorption system which combines a humidity regulator with an adsorption device (containing an adsorption material) to enhance the adsorption capacity of carbon dioxide and reduce energy consumption, and at the same time achieve cost-effective adsorption for effective adsorption. The purpose of carbon dioxide in the exhaust gas.

In order to improve the problems faced by the above-mentioned prior art, it is an object of the present invention to provide a carbon dioxide adsorption system comprising: a humidity regulator for adjusting the humidity of an exhaust gas to be treated; and an adsorption device. It is used to provide a carbon dioxide adsorbing material to adsorb carbon dioxide in the exhaust gas to be treated.

The adsorption system as described above, wherein the adsorbent material may be an APTS modified carbon nanotube, a TEPA modified carbon nanotube or a TEPA modified Y-type zeolite having a yttrium aluminum ratio of 60.

The adsorption system as described above, wherein the adsorption unit is a fixed bed adsorber or a rotary rotary ring adsorber or a rotary wheel adsorber or a fluidized floating adsorber.

The adsorption system as described above further comprises a plurality of carbon dioxide adsorption tanks for filling the carbon dioxide adsorbing material when the adsorption unit is the rotary rotary ring adsorber.

In the adsorption system as described above, when the adsorbent material is an APTS modified carbon nanotube, the humidity range thereof is preferably from 0 to 17%, more preferably from 2 to 5%.

In the adsorption system as described above, when the adsorbent material is a TEPA-modified carbon nanotube, the humidity range thereof is preferably from 0 to 17%, more preferably from 2 to 5%.

In the adsorption system as described above, when the adsorbent material is a TEPA-modified Y-type zeolite having a ruthenium ratio of 60, the humidity is preferably from 2 to 17%, more preferably from 7 to 8%.

The carbon dioxide adsorption system described above is combined with a humidifier and an adsorption device (containing an adsorbent material) to enhance the adsorption capacity of carbon dioxide and reduce energy consumption, and at the same time achieve cost-effectiveness to effectively adsorb carbon dioxide in the exhaust gas. The purpose.

The following experimental design is intended to be illustrative, and is not intended to limit the scope of the invention, and such modifications may be made without departing from the scope of the invention.

In order to fully understand the objects, features and advantages of the present invention, the present invention will be described in detail by the following specific embodiments and the accompanying drawings, which are illustrated as follows: 1 is a schematic diagram of a carbon dioxide adsorption system according to the present invention, wherein the carbon dioxide adsorption system comprises a humidity regulator 10 and an adsorption device 20.

The carbon dioxide-containing waste gas to be treated enters the humidity controller 12 from an exhaust gas outlet A to adjust the moisture content of the waste gas to be treated, and then the exhaust gas to be treated after the moisture is adjusted to flow through the adsorption device 20 After the exhaust gas to be treated enters the adsorption device 20, since the adsorption device contains an adsorbent material capable of adsorbing carbon dioxide, the carbon dioxide in the exhaust gas to be treated is adsorbed by carbon dioxide to adsorb and purify the waste gas to be treated. The carbon dioxide is used to complete the adsorption of carbon dioxide, and finally the purified exhaust gas which is purified by adsorption and purification of carbon dioxide flows out of the adsorption device 20 and flows through the gas outlet B to be discharged.

Example 1:

A carbon dioxide adsorption system 1 according to a first embodiment of the present invention is shown in FIG. 2, wherein the system comprises: a humidity regulator 10 and an adsorption device 20; wherein the adsorption device 20 comprises a plurality of carbon dioxide adsorptions. The unit 11 and the carbon dioxide adsorption unit 11 are filled with a carbon dioxide adsorbing material 13.

When the carbon dioxide adsorption system 1 performs carbon dioxide adsorption purification, the exhaust gas to be treated is blown into the carbon dioxide adsorption system 1 from a gas inlet A via a windmill 5, and first flows through the humidity control device 10, and is adjusted in this embodiment. The wet device 10 is a water spray humidifier having a function of humidifying and cooling, to adjust the moisture of the waste gas to be treated, and then the moisture to be treated to be treated is introduced into the adsorption device 20, and In Fig. 2, the arrow in the adsorption device 10 performs the flow of the gas, and the carbon dioxide in the exhaust gas to be treated is adsorbed by the carbon dioxide adsorbing material 13 in the carbon dioxide adsorbing unit 11, wherein the carbon dioxide adsorbing material 13 is adsorbed by carbon dioxide. a substrate, and the carbon dioxide adsorption substrate may be a low temperature adsorption material such as a carbon nanotube, a zeolite molecular sieve or a pore-adsorbing material in a pure ruthenium, and may be further modified by a modifier, and the modifier in the embodiment It is a modifier containing an amine functional group, and the carbon dioxide adsorbent used is an APTS modified carbon nanotube, a TEPA modified carbon nanotube or a TEPA modified bismuth aluminum ratio of 60 Y type After the exhaust gas flows through the carbon dioxide adsorption unit 11, the carbon dioxide contained therein is adsorbed by the carbon dioxide adsorbing material 13 to complete the adsorption of carbon dioxide, and finally the purified exhaust gas by adsorption and purification of carbon dioxide flows out of the adsorption. Device 20 is discharged through the gas outlet B.

Example 2:

A carbon dioxide adsorption system 2 according to a second embodiment of the present invention is shown in FIG. 3, wherein the system comprises: a humidity regulator 10 and a rotary toroidal adsorber 30; wherein the rotary rotary ring adsorber 30 It is composed of a plurality of carbon dioxide adsorption tanks 22, and the carbon dioxide adsorption tanks 22 are filled with carbon dioxide adsorbing materials, and the carbon dioxide adsorbing tanks 22 facilitate the replacement of carbon dioxide adsorbing materials.

When the carbon dioxide adsorption system 2 performs carbon dioxide adsorption purification, the exhaust gas to be treated is blown into the carbon dioxide adsorption system 2 from a gas inlet A via a windmill 5, and first flows through the humidity control device 10, which is the embodiment. The humidity controller 10 is a combination of a shell-and-tube heat exchanger and a steam humidifier, and has the functions of temperature adjustment and humidification or dehumidification to adjust the moisture and temperature of the waste gas to be treated, and then adjust the humidity. The treated exhaust gas enters the rotary rotary ring adsorber 30, and the gas flows along with the arrow of the rotary rotary ring adsorber 30 in Fig. 3, and the carbon dioxide in the waste gas to be treated is adsorbed by the carbon dioxide adsorption block. The carbon dioxide adsorbing material in the carbon dioxide adsorbing material is a carbon dioxide adsorbing substrate, and the carbon dioxide adsorbing substrate is a low temperature adsorbing material such as a carbon nanotube, a zeolite molecular sieve or a pore adsorbing material in a pure tantalum. Further modified by the modifier, the modifier in this embodiment is a modifier containing an amine functional group, and the carbon dioxide adsorbent used is an APTS modified carbon nanotube, TEP. A modified carbon nanotube or a TEPA-modified yttrium aluminum ratio of 60 Y-type zeolite; and the waste gas to be treated flows through the carbon dioxide adsorption block 22, the carbon dioxide contained therein is a carbon dioxide adsorbing material Adsorption, the adsorption of carbon dioxide is completed, and finally, the purified exhaust gas which is purified by adsorption and purification of carbon dioxide flows out of the rotary rotary ring adsorber 30, and flows through the gas outlet B.

Example 3:

A carbon dioxide adsorption system 3 according to a third embodiment of the present invention is shown in FIG. 4, wherein the system comprises: a humidity regulator 10 and a honeycomb rotor adsorber 40; wherein the honeycomb-shaped rotor adsorption The device 40 is a combination of a plurality of modified multi-channel honeycomb carbon dioxide adsorption substrates.

When the carbon dioxide adsorption system 3 performs carbon dioxide adsorption purification, the exhaust gas to be treated is blown into the carbon dioxide adsorption system 3 from a gas inlet A via a windmill 5, and first flows through the humidity control device 10, which is the embodiment. The humidity controller 10 is a water washing tower having the functions of evaporating humidification and cooling to adjust the moisture of the exhaust gas to be treated, and then the moisture to be treated to be treated is introduced into the honeycomb rotor adsorber 40, and The carbon dioxide in the exhaust gas to be treated is adsorbed by the carbon dioxide adsorbing material in the honeycomb rotor adsorber 40, wherein the carbon dioxide adsorbing material is a carbon dioxide adsorbing substrate, and the carbon dioxide adsorbing substrate may be nano carbon. a low-temperature adsorption material such as a tube, a zeolite molecular sieve or a pore-adsorbing material in a pure ruthenium, and can be further modified by a modifier. In the present embodiment, the modifier is a modifier containing an amine functional group, and the carbon dioxide used. The adsorbent material is an APTS modified carbon nanotube, a TEPA modified nano carbon tube or a TEPA modified yttrium aluminum ratio 60 Y zeolite; and the waste gas to be treated flows through the honeycomb Wheel adsorption After 40, comprising carbon dioxide within the carbon dioxide adsorbent material that is adsorbed by the carbon dioxide adsorption is completed, and finally purifying exhaust gas purifying by adsorption of carbon dioxide then flows out of the honeycomb wheel adsorber 40, the gas flowing through the exhaust outlet B.

Example 4 :

A carbon dioxide adsorption system 4 according to a fourth embodiment of the present invention is shown in FIG. 5, wherein the system comprises: a humidity regulator 10 and a fluidized bed adsorber 50; The fluidized floating bed adsorber 50 comprises a plurality of spherical adsorbing materials 55 which are combined by a fluidized bed or a fluidized bed, and the spherical adsorbing materials 55 are modified spherical or powdery or Cylindrical carbon dioxide adsorbs the substrate.

When the carbon dioxide adsorption system 4 performs carbon dioxide adsorption purification, the exhaust gas to be treated is blown into the carbon dioxide adsorption system 4 from a gas inlet A via a windmill 5, and first flows through the humidity control device 10, which is the embodiment. The humidity controller 10 is a water washing tower having the functions of evaporating humidification and cooling to adjust the moisture of the exhaust gas to be treated, and then the moisture to be treated to be treated is introduced into the fluidized floating bed adsorber 50, and The carbon dioxide in the exhaust gas to be treated is adsorbed by the spherical adsorbing material 55 in the fluidized floating bed adsorber 50, wherein the spherical adsorbing material 55 is a carbon dioxide adsorbing substrate, and the carbon dioxide adsorbing substrate is It is a low-temperature adsorption material such as activated carbon, a carbon nanotube, a zeolite molecular sieve or a pore-adsorbing material in a pure ruthenium (but not limited to the aforementioned adsorption substrate), and can be further modified by a modifier, and is modified in this embodiment. The agent is a modifier containing an amine functional group, and the carbon dioxide adsorbent used is a TEPA-modified yttrium-alumina 60 spherical Y-type zeolite or spherical activated carbon; and the waste gas to be treated flows through Fluidized floating bed After the adsorber 50, the carbon dioxide contained therein is adsorbed by the spherical adsorbing material 55 to complete the adsorption of carbon dioxide, and finally the purified exhaust gas which is adsorbed and purified by carbon dioxide flows out of the fluidized floating bed adsorber 50, and flows through the adsorbent 50. The gas outlet B is discharged.

Adsorption substrate modification:

The modified substrate of the embodiment of the present invention is modified by using a low temperature adsorption material such as a carbon nanotube, a zeolite molecular sieve, a mesoporous pure germanium material, etc. (but not limited to the aforementioned adsorption substrate), and the substrate The forming form may be in the form of powder, granules, flakes, spheres, cylinders, fibers, honeycombs or any combination thereof, and an amine-based solvent such as 3-aminopropyl-Triethoxysilane (APTS), Tetraethylenepentamine (TEPA) or other amine-based compounds are mixed and stirred (but not limited to the aforementioned modifier), and a suitable amount of a binder such as an epoxy resin may be added to enhance the adsorption and desorption efficiency and to heat the substrate surface. It has an amine functional group and is capable of adsorbing carbon dioxide gas. The upgrading steps are as follows:

(1) mixing and adsorbing the adsorption substrate with a specific concentration of an amine-based solvent (which may also be moderately added to the epoxy resin);

(2) heating the mixed solution to boiling for several hours by a closed reflux heating method;

(3) separating the adsorbent material from the solution by filtration after the solution is cooled;

(4) The filtered adsorbent material is dried to obtain a modified adsorbent having an amine functional group.

Results of the examples:

The test of the performance of the device is carried out with CO ₂ -containing exhaust gas, wherein the composition of the CO ₂ -containing exhaust gas is: CO ₂ 10~50% (v/v), water gas content 0~17.5% (v/v), and the rest It is nitrogen gas, and the in-flow adsorption temperature ranges from 20 ° C to 80 ° C; and is filled in the adsorption devices of the carbon dioxide: pure pore material such as MCM-41 (honeycomb or granular or film), zeolite ( Honeycomb (granular or granule or film), carbon nanotubes (honeycomb or granular or film), carbon dioxide adsorption purification test containing CO ₂ waste gas.

Tested for the adsorption of carbon dioxide by amine-modified nanocarbon tubes with known exhaust gas (CO ₂ 15% (v/v), temperature 50-60 ° C), adsorption without known humidity adjustment in the absence of moisture The results are based on APTS and TEPA amine-modified carbon nanotubes. The results are shown in Table 1:

It can be seen from the results in Table 1 that when the humidity of the exhaust gas to be treated is not adjusted, the adsorption amount of the APTS modified carbon nanotubes is 70-90 mg/g, and the adsorption amount by the TEPA-modified carbon nanotubes is 95~120mg/g.

Then, the temperature is adsorbed at a temperature of 50 to 60 ° C, a desorption temperature of 120 ° C, 15% CO ₂ , and an anhydrous gas in a flue gas atmosphere, and after 20 adsorptions and desorptions, the adsorption of each adsorbent is measured. The response rate, the results are shown in Table 2 below:

It can be seen from the above Table 2 that the average adsorption recovery rate of the modified carbon nanotubes can be higher than 90%, thereby knowing that the modified carbon nanotubes have high ability to adsorb CO ₂ , and The adsorption recovery rate after regeneration by APTS modified carbon nanotubes is higher than that of TEPA modified carbon nanotubes.

The modified carbon nanotubes were subjected to CO ₂ adsorption test under the conditions of 50-60 ° C temperature, 15% CO ₂ and water-gas content 0-17%. The adsorption performance is shown in Table 3 below:

It can be proved from Table 3 that after the modified carbon nanotubes are affected by the humidity of the exhaust gas, the adsorption amount increases with the increase of the humidity, and the APTS modified carbon nanotubes can be increased to the adsorption capacity of 85-110 mg/g of carbon dioxide. The TEPA modified carbon nanotubes can be increased to 100~150mg/g carbon dioxide adsorption capacity, which means that the moisture of the exhaust gas to be treated can effectively increase the adsorption amount of carbon dioxide.

After the Y60 zeolite was coated with TEPA, the humidity effect (CO ₂ = 15%, temperature 60 ° C) was tested. The results are shown in Fig. 6. It can be seen from Fig. 6 when the humidity range is 0 to 8%. As the moisture content increases, the amount of carbon dioxide adsorbed increases. When the moisture content is 7 to 8%, the highest adsorption value of carbon dioxide is 190 mg/g or more.

It can be seen from the above results that the carbon dioxide adsorption system provided by the present invention can effectively increase the adsorption amount of carbon dioxide in the exhaust gas to be treated by means of a humidity regulator and an adsorption device.

When the adsorbent material of the adsorption device is an APTS modified carbon nanotube or a TEPA modified carbon nanotube, the preferred humidity range is 0 to 17%, and the better humidity range is 2 to 5%; When the adsorbent material of the adsorption device is TEPA modified by TEPA, the preferred humidity range is 2 to 17%, and the optimum humidity range is 7 to 8%.

It can be seen from the above specific embodiments that the carbon dioxide adsorption system provided by the present invention utilizes a humidity regulator and an adsorption device with an adsorbent material to effectively adsorb carbon dioxide in the exhaust gas to be treated, and at the same time, the adsorbent material in the adsorption device It can also be reused, that is, the removal of carbon dioxide on the adsorbent material by desorption can effectively reduce the cost of carbon dioxide purification, and at the same time effectively achieve the effect of repeated use of resources, and achieve the purpose of energy saving and carbon reduction.

1. . . Carbon dioxide adsorption system

2. . . Carbon dioxide adsorption system

3. . . Carbon dioxide adsorption system

5. . . windmill

10. . . Humidifier

11. . . Carbon dioxide adsorption unit

13. . . Carbon dioxide adsorbent

20. . . Adsorption device

twenty two. . . Carbon dioxide adsorption box

30. . . Rotary toroidal adsorber

40. . . Honeycomb rotor adsorber

50. . . Fluidized floating bed adsorber

55. . . Spherical adsorbent

Figure 1 is a schematic view of a carbon dioxide adsorption system of the present invention.

Fig. 2 is a schematic view showing a carbon dioxide adsorption system according to a first embodiment of the present invention.

Fig. 3 is a schematic view showing a carbon dioxide adsorption system according to a second embodiment of the present invention.

Figure 4 is a schematic view showing a carbon dioxide adsorption system according to a third embodiment of the present invention.

Fig. 5 is a schematic view showing a carbon dioxide adsorption system according to a fourth embodiment of the present invention.

Figure 6 shows the effect of humidity on the carbon dioxide adsorption rate of Y60 (TEPA).

10. . . Humidifier

20. . . Adsorption device

A. . . Gas inlet

B. . . Gas outlet

Claims (3)

A carbon dioxide adsorption system comprising: a humidity regulator for adjusting the humidity of an exhaust gas to be treated; and an adsorption device for supplying a carbon dioxide adsorbing material to adsorb carbon dioxide in the exhaust gas to be treated; The adsorbent material may be an APTS modified carbon nanotube, a TEPA modified carbon nanotube or a TEPA modified yttrium aluminum ratio of 60 Y zeolite; when the adsorbent is APTS modified nanometer When the carbon tube is used, the humidity range is 2~5%; when the adsorbent material is TEPA modified carbon nanotube, the humidity range is 2~5%; when the adsorbent material is TEPA modified When 60 Y zeolite is used, its humidity ranges from 7 to 8%. The adsorption system of claim 1, wherein the adsorption unit is a fixed bed adsorber or a rotary rotary ring adsorber or a rotary wheel adsorber or a fluidized floating adsorber. The adsorption system of claim 2, when the adsorption unit is the rotary toroidal adsorber, further comprising a plurality of carbon dioxide adsorption tanks for filling the carbon dioxide adsorbent.