JP3084248B2 - Two-stage adsorption / separation equipment and method for recovering carbon dioxide from flue gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating a cleaning gas and a regeneration gas, a sprinkling dust tower, an activated alumina, for separating and recovering carbon dioxide with high purity from flue gas discharged during fossil fuel combustion. Two-column dehumidifier filled with
A three-column single-stage adsorption separation device filled with synthetic zeolite,
Two-stage or three-stage two-stage adsorption / separation apparatus filled with synthetic zeolite, carbon dioxide adsorption / separation equipment made of a blower and a vacuum pump, and two-stage carbon dioxide adsorption / separation method using the equipment It is.

[0002]

2. Description of the Related Art Carbon dioxide contained in flue gas discharged into the atmosphere is known as a component that contributes most to causing global warming, and efforts to reduce carbon dioxide internationally are being made. And regulations have been made. Therefore, it is necessary to convert the carbon dioxide into another chemical substance to recover the carbon dioxide or to separate and concentrate the carbon dioxide from the flue gas in order to fix the carbon dioxide. On the other hand, high-purity carbon dioxide can be used for welding gas, raw materials for various chemical substances, dry ice, carbonated drinks, and the like.

Hitherto, an absorption process technique has been widely used for separating and concentrating carbon dioxide from a mixed gas. However, in order to recover carbon dioxide from exhaust gas containing oxides and various impurities such as combustion exhaust gas, there were difficulties such as deterioration of the absorbing solution, corrosion, etc. Are known.

In the adsorption step, the step of separating carbon dioxide is generally a one-stage adsorption / separation apparatus composed of 2 to 4 adsorption towers (see Japanese Patent Application Laid-Open No. 3-226911).
There is a two-stage separation device composed of eight adsorption towers (see Japanese Patent Application Laid-Open No. 5-228326). Activated carbon or synthetic zeolite is used as the adsorbent. The adsorption type separation device filled with synthetic zeolite contains about 5-1 water.
When supplying the combustion exhaust gas containing about 2 vol.%, It is possible to prevent a decrease in the adsorption performance of the synthetic zeolite filled in the main adsorption / separation apparatus by supplying the dry exhaust gas from which the moisture has been sufficiently removed in advance. .

[0005]

SUMMARY OF THE INVENTION From a flue gas containing a carbon dioxide concentration of about 8-12 vol.% In a raw material exhaust gas, a single-stage adsorption / separation apparatus comprising 2-4 adsorption towers is used to remove carbon dioxide. When high purity is recovered, the recovery rate is low and a relatively large amount of power is consumed. In such a case, 2
When the carbon dioxide is recovered using a step-type adsorption separation process, the recovery rate can be maintained as high as 80% or more, and the purity is 99 vol.%.
Although the above carbon dioxide can be recovered, the number of adsorption towers is 6
-8 pieces, which increases the equipment investment cost and the adsorbent maintenance cost. In order to improve such a point, an attempt is made to solve the problem by a two-stage adsorption / separation apparatus having a small number of adsorption towers and a high process efficiency.

When high-purity carbon dioxide is produced from a raw material exhaust gas containing a large amount of water using a synthetic zeolite as an adsorbent, a pretreatment dehumidifier is connected to a carbon dioxide adsorption / separation device to perform pretreatment. By increasing the dehumidifying efficiency of the dehumidifying tower, it is possible to prevent a decrease in productivity of the main adsorption / separation apparatus due to water contamination. That is, efficient regeneration of the dehumidification tower can be achieved by exchanging heat between the waste heat of the combustion exhaust gas and the gas discharged from the adsorption step and regenerating the pretreatment dehumidification tower.

[0007] The cleaning gas is exchanged with the high-temperature raw material exhaust gas in the two-stage adsorption separation apparatus and supplied to the adsorption tower where the cleaning process proceeds, thereby making the regeneration of the two-stage adsorption tower efficient and reducing the amount of the raw material exhaust gas. And the overall effect of the process can be improved.

On the other hand, the exhaust gas from the adsorption tower in which the adsorption step and the washing step of the two-stage adsorption apparatus are advanced contains a large amount of carbon dioxide. If this is mixed with the flue gas containing a large amount of water to be supplied to the pretreatment dehumidification tower and supplied to the dehumidification tower again instead of being discarded to the atmosphere, loss of carbon dioxide occurs in the dehumidification tower and the separation process The efficiency of the system decreases. In order to reduce such detrimental effects, the overall efficiency of the separation apparatus is obtained by supplying the entire amount of exhaust gas discharged from the adsorption step and the washing step of the two-stage adsorption apparatus to the one-stage adsorption tower and recovering carbon dioxide. You can measure improvement.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to produce high-purity carbon dioxide from a flue gas containing a large amount of water using a synthetic zeolite as an adsorbent.
An object of the present invention is to prevent a decrease in the productivity of the adsorption / separation apparatus due to water contamination by increasing the dehumidification effect of the pretreatment dehumidification tower by connecting the pretreatment dehumidifier with the carbon dioxide adsorption / separation apparatus.

Another object of the present invention is to regenerate a two-stage adsorption tower by exchanging a cleaning gas with a high-temperature raw material exhaust gas in a two-stage adsorption / separation apparatus and supplying the same to an adsorption tower in which a washing process is performed. And to obtain a double effect of cooling the raw material exhaust gas to improve the overall process efficiency.

Still another object of the present invention is to reduce the total amount of exhaust gas discharged from the adsorption step and the washing step of the two-stage adsorption separation apparatus by one.
The objective is to improve the overall efficiency of the separation device by feeding it to the stage adsorption tower and recovering carbon dioxide.

According to the present invention, the composition of carbon dioxide is preferably 8-15 vo.
In order to recover carbon dioxide with a purity of 95 vol.% or more from the flue gas of a combined heat or thermal power plant that is l.%, a heat exchanger for heating cleaning gas and regeneration gas,
It is characterized by comprising a two-stage dehumidifier, a three-stage one-stage adsorption / separation device, and a two-column two-stage adsorption / separation device.

[0013]

DETAILED DESCRIPTION OF THE INVENTION High-purity carbon dioxide from flue gas discharged when bunker C oil or COM (coal oil mixture) is burned in a combined heat or thermal power plant shown in FIGS. The detailed characteristics and operating method of the two-stage adsorption separation step (I) for recovering the phenol are as follows.

Operation method of the pretreatment step The flue gas is generally released to the atmosphere after passing through the deaeration, denitrification and the above-mentioned dust collector EP. The composition of such flue gas is 8 to 15 vol. .%, Moisture 5-12vol.%,
Oxygen 3-8vol.%, SO _x and NO _X are each 20-30Ppm,
The rest is dust about 125 / M ³ is nitrogen. Temperature 55 −300
After the combustion exhaust gas 41 is supplied to the exchanger 20 by the blower 30 and the cleaning gas 54 of the two-stage adsorption / separation apparatus is heated to an appropriate temperature according to the process operation conditions, the valve 13a is connected to the adsorption tower where the cleaning process proceeds. -C.

The combustion exhaust gas 42 that has passed through the heat exchanger 20 heats the regeneration gas 61 of the pretreatment dehumidification tower in the heat exchanger 21 and then flows into the lower end of the sprinkling dust tower 29 for dust removal and cooling.

In the sprinkling dust removing tower 29, a cooling water 65 is supplied to the upper end of the tower by a water pump 33 to cool the combustion exhaust gas to near normal temperature, and the dust removed and the heated waste water are discharged at the lower end of the tower.

The wet exhaust gas 44 saturated with moisture at the upper end of the sprinkler / dust tower is passed through the filter 22 to remove fine dust, and supplied to the dehumidifiers 23a and 23b filled with activated alumina via the automatic valves 1a and 1b. The drying exhaust gas 46 is obtained through the automatic valves 3a and 3b at the upper end of the dehumidifying tower.

The dried exhaust gas is supplied to the one-stage adsorption / separation device via the raw material exhaust gas storage tank 26 of the one-stage adsorption / separation device.

Operating method of the single-stage adsorption / separation apparatus A three-column single-stage adsorption / separation apparatus filled with synthetic zeolite is composed of a reverse pressure accumulation step, a pressure accumulation step, an adsorption step, a recovery step, a desorption step, and a low pressure washing / desorption step. Investigate one cycle operation.

In the reverse pressure accumulation step, the gas discharged from the outlet of the adsorption tower 24c in which the recovery step of the single-stage adsorption / separation apparatus proceeds proceeds to the end of the adsorption tower 24a placed at a minimum pressure of 100-250 mmHg in one cycle step. To the carbon dioxide concentration front (abso
rbion front) in the direction in which the source gas is supplied.
The composition of the gas used at the reverse pressure is about 0.5 vo of carbon dioxide
l.%, the balance being mainly nitrogen and oxygen.

Since the pressure of the adsorption tower is about 500 mmHg when the back pressure is completed, the dried exhaust gas in the storage tank 26 is automatically valved to the adsorption tower 24a in order to raise the pressure of the adsorption tower to the operating pressure of the adsorption step. When feeding through 5a, the automatic valve 16 closes and adjusts the manual valve 16a to increase the pressure of the adsorption tower to about 800-900 mmHg while uniformly adjusting the gas flow rate flowing into the adsorption tower during the pressure accumulation step.

The pressure 8 is applied to the adsorption tower 24a whose pressure has been completed.
The dry exhaust gas in the storage tank 26 at around 00-900 mmHg is supplied via the automatic valves 16, 5a, at which time carbon dioxide, nitrogen and oxygen are separated. The strongly adsorbed carbon dioxide is adsorbed by the synthetic zeolite, and the weakly adsorbed components of oxygen and nitrogen are discharged through the automatic valve 8a together with a small amount of carbon dioxide (about 0.5-2 vol.%).

While the adsorption tower 24a goes through the reverse pressure accumulation step, the raw material pressure accumulation step, and the adsorption step, the recovery step proceeds in the adsorption tower 24b.

In the recovery step, the gas 48 discharged from the outlet of the adsorption tower in which the adsorption step and the washing step of the two-stage adsorption / separation apparatus proceed is supplied to the adsorption tower 24c after the adsorption step to reduce the amount of carbon dioxide adsorbed. increase.

The exhaust gas 52 in the recovery step via the automatic valve 9c is mixed with the exhaust gas 51 in the adsorption step 61, which is heated while passing through the heat exchanger 21 before being used as the regeneration gas 62 for the dehumidification tower. .

After the recovery step, the adsorption tower 24b goes through a desorption step. Vacuum pump 31 for desorption of one-stage adsorption separation device
Is operated to lower the tower pressure to about 100-250 mmHg to desorb the adsorption tower, and the desorbed gas obtained at this time is supplied to the automatic valve 7b.
And is sent to the storage tank 27 via the storage tank 27 and is used as a raw material gas for the two-stage adsorption / separation apparatus.

After the desorption step, low pressure cleaning desorption is performed. Part of the exhaust gas discharged from the outlet of the adsorption tower 24a in which the adsorption step is performed is partially discharged by the manual valve 18 and the automatic valve 10.
b. As a result, the desorption of carbon dioxide adsorbed at the tail of the tower is increased, and the desorbed gas is sent to the storage tank 27 via the automatic valve 7b and supplied as a raw material gas for the two-stage adsorption separator.

Operation method of the two-stage adsorption / separation apparatus One cycle operation of the two-stage adsorption / separation apparatus includes a raw material gas accumulating step, an adsorption step, a washing step, and a desorption step.

The raw material gas containing about 30-50 vol.% Of carbon dioxide obtained through continuous operation of the two-stage adsorption separation apparatus is stored in the storage tank 27. During the pressure accumulation step, the manual valve 17a and the automatic valve 17a are used. The source gas 53 via the valve 11a is supplied to the adsorption tower 25a. The initial pressure of the pressure accumulation step is about 50 mmHg and the final pressure is 800-880 mmHg.
The manual valve 17a is appropriately adjusted to uniformly adjust the gas supply flow rate during the pressure accumulation process.

After the pressure accumulating step, the raw material gas 53 is supplied to the adsorption tower 25a through the automatic valves 17 and 11a at a constant pressure near 800 to 880 mmHg to selectively separate carbon dioxide and oxygen / nitrogen. During the progress of the adsorption step, the exhaust gas discharged from the outlet of the adsorption tower is passed through the automatic valve 14a to the exhaust valve 1a.
The carbon dioxide is supplied to the adsorption tower in which the recovery step of the step adsorption separation step proceeds, and is recovered.

After the adsorption step is completed, an equilibrium amount of nitrogen and oxygen are adsorbed on the zeolite and the space volume between the adsorbents. It is obtained by producing high-purity carbon dioxide and replacing residual nitrogen and oxygen. This is produced by supplying a part 54 of the product carbon dioxide via the automatic valve 12c to the adsorption tower 25c where the adsorption step has been completed. Can be

The composition of carbon dioxide in the exhaust gas of the washing step varies from about 25 vol.% To 99 vol.% In accordance with the operating conditions. It is supplied to the adsorption tower where the recovery process proceeds.

In the desorption step, the adsorption tower is moved for about 5
The pressure is reduced to 0-70 mmHg, and high-purity carbon dioxide is stored in the product gas storage tank 28 through the automatic valve 12b. A part of the desorbed gas is supplied to the adsorption tower in which the cleaning process is performed.

Description of Two-Stage Adsorption Type Separation Process (II) FIGS. 3 and 4 show adsorption for recovering high-purity carbon dioxide from flue gas discharged during combustion of bunker-C oil or COM in a heat-combination or thermal power plant. The process flow diagram and continuous operation diagram of the separation apparatus (II) are shown.

The operation method of the pretreatment step and the operation method of the single-stage adsorption separation apparatus are the same as those described in the two-stage adsorption separation step (I). Differences in the operation method of the two-stage adsorption separation device in the two-stage adsorption separation process (II) are as follows.

Operation method of the two-stage adsorption / separation apparatus One cycle operation of the two-stage adsorption / separation apparatus is composed of a raw material gas accumulating step, an adsorbing step, a washing step and a desorbing step, and is performed in two adsorption towers 25a and 25b. While the adsorption tower 25a has gone through the raw material pressure accumulation, adsorption step, and washing step, the desorption step proceeds in the adsorption tower 25b.

The gas containing about 30-50 vol.% Of carbon dioxide obtained through continuous operation of the single-stage adsorption separation apparatus is stored in the storage tank 27. During the pressure accumulating process, the raw material gas 53 via the manual valve 17a and the automatic valve 11a is used.
Is supplied to the adsorption tower 25a.

The initial pressure in the pressure accumulation step is about 50-70 mmHg and the final pressure is 800-880 mmHg. The manual valve 17a is adjusted appropriately to keep the accumulated gas flow rate almost constant.

In the adsorption step, the raw material gas 53 is supplied to the automatic valve 1
The gas is supplied to the adsorption tower 25a at a constant pressure near 800 to 880 mmHg via 7, 11a to selectively separate carbon dioxide and oxygen / nitrogen. Exhaust gas from the adsorption step is supplied to the adsorption tower through which the recovery step of the single-stage adsorption / separation step proceeds through the automatic valve 14a to recover carbon dioxide containing the exhaust gas.

After the adsorption step is completed, the equilibrium amounts of nitrogen and oxygen are adsorbed on the volume of air between the adsorbents and the synthetic zeolite. The adsorption gas is supplied at a higher supply flow rate than during the operation of the two-stage adsorption separation process (I), and the same amount of the adsorption gas is treated in a given operation time.

After the adsorption step is completed, the adsorption tower 25a goes through a washing step. High-purity carbon dioxide in the storage tank 28 is supplied to the adsorption tower 25a by adjusting the manual valve 19a. High-purity carbon dioxide obtained by reducing the pressure of the adsorption tower 25a to about 50-70 mmHg in the adsorption tower 25a during the course of accumulating the raw material, the adsorption step, and the washing is sent to the storage tank 28 via the automatic valve 13b.

A part of the desorbed gas is supplied to the adsorption tower where the cleaning process proceeds, but the amount of the cleaning gas is adjusted by the manual valve 19a, and the remainder is produced as product carbon dioxide 60.

Hereinafter, the present invention will be described in detail with reference to embodiments.

[0044]

【Example】

Example 1 When the stage adsorption type separation apparatus (I) of FIG. 1 was applied to flue gas discharged from a boiler in accordance with the one-cycle continuous operation diagram of FIG. 2, FIG. 5 shows the pressure change of the adsorption tower, and FIG. The temperature change according to time at the center of the adsorption tower 24a of the stage adsorption separation device is
FIG. 7 shows the temperature change with time of the center of the adsorption tower 25a of the two-stage adsorption separation apparatus, and FIG. 8 shows the result of continuous operation.

During continuous operation, the pressure in the adsorption tower was 820-830 mmHg during the adsorption step and the recovery step in the single-stage adsorption tower, and the final pressure in the low-pressure washing / desorption step was 110 mmHg.

In the two-stage adsorption separation apparatus, the adsorption step is 800
mmHg, the washing step was operated at a pressure of 790 mmHg, and the final pressure of the desorption step was 65 mmHg.

In FIG. 6, it can be seen that about 85% of the adsorption tower had a temperature rise due to carbon dioxide adsorption during the recovery step of the single-stage adsorption separation apparatus.

It can be seen that the effect of the recovery step for recovering the exhaust gas containing a large amount of carbon dioxide discharged from the outlet of the adsorption step and the washing step tower of the two-stage adsorption separation apparatus is high.

When the composition of carbon dioxide in the dried exhaust gas passed through the dehumidification tower was 9.29 vol.% On average, the results obtained through continuous operation of this development process showed that the purity was 99.70 and 99.42.
, 99.22, and 98.79 vol.% Of product carbon dioxide, but the recovery rate is 80.29, 89.21, 88.76, and 92.4%, respectively.
The product gas production flow rates per packed weight of the synthetic zeolite are 0.457, 0.481, 0.485, and 0.482 N1 / kg / min, respectively, and the cleaning gas flow rates supplied to the washing step of the two-stage adsorption separation apparatus are 0.318, respectively. 0.278 and 0.277 N1 / kg / min.

Example 2 When the two-stage adsorption separation apparatus (II) shown in FIG. 3 was applied to the combustion exhaust gas discharged from the boiler according to the one-cycle continuous operation diagram in FIG. 4, FIG. 9 shows the pressure change in the adsorption tower. And FIG.
FIG. 11 shows a temperature change according to time at the center of the adsorption tower 24a of the two-stage adsorption / separation device, FIG. 11 shows a temperature change according to time at the center of the adsorption tower 25a of the two-stage adsorption / separation device, and FIG.

During continuous operation, during the adsorption step and the recovery step in the single-stage adsorption tower, the pressure in the adsorption tower is 790-810 mmHg, the final pressure in the low pressure washing / desorption step is 150 mmHg, and the final pressure in the desorption step is
It was 30 mmHg. In a two-stage adsorption separation device, the adsorption process
The washing step was operated at a pressure of 780 mmHg, the washing step at 90-800 mmHg, and the final pressure of the desorption step was 55 mmHg.

When the number of adsorption towers in the two-stage adsorption separation apparatus is two, almost the same effect can be obtained in the efficiency of the process.

In FIG. 12, the purity of the product carbon dioxide is 99.2, 9
The recovery rates are 8.45, 96.57 and 95.56 vol.% Respectively.
70.0, 76.42, 75.46, 76.8%, and the product gas production flow rates per synthetic zeolite charge weight were 0.506, 0.540, and 0.540, respectively.
0.511, 0.517 N1 / kg / min, and the washing gas flow rates supplied to the washing step of the two-stage adsorption separation apparatus were 0.279, 0.223, respectively.
, 0.148, 0.119 N1 / kg / min.

[0054]

According to the first and second embodiments of the present invention,
The product carbon dioxide with a purity of 98.79 vol.% When operated with an adsorption-type separation device that supplies the entire amount of exhaust gas discharged from the two-stage adsorption process to the column where the recovery process of the one-stage adsorption column proceeds. With a 92.4% recovery rate.

The two-stage adsorptive separation apparatus (Example 2) is applied to the combustion exhaust gas discharged from the boiler to obtain a purity of 95.56-99.2.
The productivity per unit adsorbent weight, which allows to obtain 2 vol.% Of product carbon dioxide, has been increased to 0.506-0.517 N1 / kg / min. High-purity carbon dioxide could be produced from the combustion exhaust gas by a simpler process than a three-column two-stage adsorption separation apparatus.

The high-purity carbon dioxide recovered by utilizing the present invention removes impurities (SO _X , NO _X moisture, etc.) contained in trace amounts, and then is used for food, welding, urea fertilizer such as dry ice and liquid carbon dioxide. It can be used as a raw material for manufacturing and other industries.

[Brief description of the drawings]

FIG. 1 shows a three-stage one-stage column for recovering carbon dioxide from flue gas.
FIG. 3 is a diagram (I) of a two-stage adsorption / separation process constituted by two stages and three columns.

FIG. 2 shows a three-stage one-stage column for recovering carbon dioxide from flue gas.
FIG. 2 is a one-cycle operation diagram of a two-stage adsorption separation process diagram (I) configured in a two-stage three-column system.

FIG. 3 shows a three-stage one-stage column for recovering carbon dioxide from flue gas;
FIG. 2 is a diagram (II) of a two-stage adsorption / separation process composed of two stages and three columns.

FIG. 4 shows a one-stage, three-stage column for recovering carbon dioxide from flue gas;
FIG. 3 is a one-cycle operation diagram of a two-stage adsorption / separation process diagram (II) configured in a two-stage two-column system.

FIG. 5 is a graph of the pressure change of the adsorption tower during one cycle operation of the two-stage adsorption separation process (I).

FIG. 6 shows a two-stage adsorption separation process (I) during one cycle operation.
It is a graph of the temperature change of the central part of an adsorption tower in a stage adsorption separation process.

FIG. 7 shows a two-stage adsorption separation process (I) during one cycle operation.
It is a graph of the temperature change of the central part of an adsorption tower in a stage adsorption separation process.

FIG. 8 is a graph showing a one-cycle operation result of the two-stage adsorption / separation step (I).

FIG. 9 is a graph showing the pressure change of the adsorption tower during one cycle operation of the two-stage adsorption separation step (II).

FIG. 10 is a graph showing a change in temperature at the center of the adsorption tower in the single-stage adsorption / separation step during one cycle operation of the two-stage adsorption / separation step (II).

FIG. 11 is a graph showing a change in temperature at the center of the adsorption tower in the two-stage adsorption / separation step (II) during one cycle operation.

FIG. 12 is a graph showing the results of one cycle operation of the two-stage adsorption / separation process chart (II).

[Explanation of symbols]

1a, 1b, 3a, 3b, 5a, 8a, 9c, 10b,
11, 12b, 12c, 13b, 14a, 16, 17 ...
Automatic valve, 13c ... Valve, 11a, 16a, 17
a, 18, 19a: manual valve, 21: heat exchanger, 23
a, 23b: dehumidifying tower, 24a, 24b, 24c, 25
a, 25c: adsorption tower, 26, 27, 28: storage tank, 30
... Blower, 31, 32 ... Vacuum pump, 33 ... Water pump,
41, 42: Combustion exhaust gas, 46: Dry exhaust gas, 48: Gas, 51, 52 ... Exhaust gas, 53: Raw material gas, 54: Part of product carbon dioxide, 56: Adsorption process exhaust gas, 60: Product carbon dioxide, 62 ... Regeneration gas

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Jung Seungchul 100-4 Seodong-dong, Dong-gu, Ulsan-si, Gyeongsangnam-do, Republic of Korea JP-A-7-80246 (JP, A) JP-A-62-46911 (JP, A) JP-A-1-176416 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 53 / 62 B01D 53/04 B01D 53/34

Claims (5)

(57) [Claims] 1. A cleaning gas and a regeneration gas heating system for recovering carbon dioxide having a purity of 95 vol.% Or more from the flue gas of a combined heat or thermal power plant having a carbon dioxide composition of 8 to 15 vol. Combustion flue gas characterized by comprising a heat exchanger, a sprinkler / dust tower, a two-tower dehumidifier, a three-tower one-stage adsorption / separation device, a two-tower two-stage adsorption / separation device, a blower and a vacuum pump, -Stage adsorption separation equipment for recovering wastewater. 2. A cleaning gas and a regeneration gas heating system for recovering carbon dioxide having a purity of 95 vol.% Or more from the flue gas of a combined heat or thermal power plant having a carbon dioxide composition of 8 to 15 vol. Adsorption process of a two-stage adsorption / separation device consisting of a heat exchanger, a sprinkler / dust tower, a two-column dehumidifier, a three-column one-stage adsorption / separation device, and a three-column two-stage adsorption / separation device In addition, the exhaust gas from the washing process is supplied to the adsorption tower where the adsorption process of the single-stage adsorption separation device has been completed to improve the recovery rate and productivity of carbon dioxide, and the combustion exhaust gas at a temperature of 55-300 ° C is supplied to the sprinkler dust tower. Before the heat treatment, the entire amount of the adsorption exhaust gas and the cleaning exhaust gas in the two-stage adsorption separation process is exchanged with the high-temperature combustion exhaust gas, and the heated regeneration gas is supplied to the pretreatment dehumidification tower. , 2-stage cleaning gas heat exchanger washed gas adsorption separation apparatus 2, characterized in that heating
Stepwise carbon dioxide adsorption separation method. 3. The exhaust gas discharged from the adsorption step and the washing step of the two-stage adsorption / separation apparatus according to claim 2,
A two-stage carbon dioxide adsorption / separation method characterized in that it is supplied to an adsorption tower in which an adsorption step of a two-stage adsorption / separation apparatus has been completed to improve the recovery rate and productivity of carbon dioxide. 4. The method according to claim 2, wherein before the flue gas having a temperature of 55 to 300 ° C. is supplied to the sprinkler / dust tower, the total amount of the adsorbed exhaust gas and the cleaning exhaust gas in the two-stage adsorption / separation step is exchanged with the high-temperature flue gas. A two-stage carbon dioxide adsorption / separation method for supplying a heated regeneration gas to a pretreatment dehumidification tower. 5. The two-stage system according to claim 2, wherein the cleaning gas is heated by exchanging heat with the cleaning gas of the two-stage adsorption separation apparatus before supplying the flue gas having a temperature of 55 to 300 ° C. to the sprinkler / dust tower. Carbon dioxide adsorption separation method.