KR20200114027A - Method of absorbing and separating acid gas and apparatus for absorbing and separating acid gas - Google Patents

Abstract

Disclosed are a method of absorbing/separating acid gas and an apparatus for absorbing/separating acid gas. The method of absorbing/separating acid gas includes the steps of: (a) manufacturing a sulfur oxide absorbent (S2) which absorbs sulfur oxide (SOx) from exhaust gas (G1) by contacting the exhaust gas (G1) with a sulfur oxide absorbent (S1), and an exhaust gas (G2) from which the sulfur oxide is separated; (b) manufacturing a carbon dioxide absorbent (C2) which absorbs carbon dioxide (CO_2) from the exhaust gas (G2) by contacting the exhaust gas (G2) with a carbon dioxide absorbent (C1), and an exhaust gas (G3) from which the carbon dioxide is separated; and (c) manufacturing a carbon dioxide absorbent (C3) from which a gas (CG1) containing carbon dioxide and the gas (CG1) containing carbon dioxide are separated by removing carbon dioxide from the carbon dioxide absorbent (C2). According to the method and apparatus for absorbing/separating acid gas of the present invention, it is possible to significantly reduce the volume of equipment and the installation site by using a small, highly efficient membrane contactor. In addition, according to the method and apparatus for absorbing/separating acid gas of the present invention, sulfur oxides and carbon dioxide can be selectively absorbed and separated from the exhaust gas, and sulfur oxides can be recycled by making ammonium sulfate ((NH_4)_2SO_4), which is a fertilizer as a byproduct.

Description

Acid gas absorption/separation method and acid gas absorption/separation device {METHOD OF ABSORBING AND SEPARATING ACID GAS AND APPARATUS FOR ABSORBING AND SEPARATING ACID GAS}

The present invention relates to an acid gas absorption/separation method and an acid gas absorption/separation apparatus, and more particularly, to a method and apparatus for selectively absorbing and separating sulfur oxides and carbon dioxide from exhaust gas using a membrane contactor.

As the use of fossil fuels increases due to industrial development and improved living standards, air pollution by nitrogen oxides (NOx), sulfur oxides (SOx) and carbon dioxide (CO ₂ ) in exhaust gases emitted after fuel combustion, causing acid rain, photochemistry in the atmosphere The suffering of ordinary citizens is extreme due to the ultrafine dust generated secondary by the reaction and global warming. Existing general exhaust gas scrubber methods include a packed tower, a spray tower, a venturi scrubber, and a bubble column. However, even if the above conventional technologies are advanced, it is difficult to expect improvement in removal efficiency and miniaturization of the device size, and furthermore, there are many problems such as flooding and channeling of fluid in the device. Exhaust gas post-treatment facilities used in existing power plants, oil refineries and petrochemical plants, and ships are severely restricted by the area and height occupied by the facilities.

Currently, the process of producing gypsum (CaSO ₄ ) using slaked lime (CaO) is mainly used to remove sulfur oxides (SOx) from exhaust gas. However, high-quality limestone (CaCO ₃ ) and slaked lime, which are sulfur oxide absorbents, are depleted by continuous mining, so it is expected that it will be difficult to obtain high-quality gypsum any more.

An object of the present invention is to provide a method and apparatus for absorbing/separating acid gas that can significantly reduce the volume of equipment and the installation site by using a small, highly efficient membrane contactor.

In addition, an object of the present invention is to selectively absorb and separate sulfur oxides and carbon dioxide from flue gas, and in particular, sulfur oxides are ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), that is, acid gas absorption/ It is to provide a separation method and apparatus.

According to an aspect of the present invention, (a) a sulfur oxide absorbent (S2) which absorbs sulfur oxide (SOx) from the exhaust gas (G1) by contacting the exhaust gas (G1) with a sulfur oxide absorbent (S1), and the sulfur oxide Producing the separated exhaust gas (G2); (b) preparing a carbon dioxide absorbent (C2) absorbing carbon dioxide (CO ₂ ) from the exhaust gas (G2) by contacting the exhaust gas (G2) with a carbon dioxide absorbent (C1), and an exhaust gas (G3) from which the carbon dioxide is separated step; And (c) removing carbon dioxide from the carbon dioxide absorbent (C2) to prepare a carbon dioxide absorbent (C3) from which a gas containing carbon dioxide (CG1) and the gas containing carbon dioxide (CG1) are separated. A method of absorption/separation of acidic gases is provided.

In addition, in the absorption/separation method of the acidic gas, the gas containing carbon dioxide (CG1) is a gas additionally containing ammonia (CG2), and (d) the gas (CG2) is mixed with the sulfur oxide absorbent (S2). It may further include preparing a sulfur oxide absorbent (S3) in which the ammonia is absorbed from the gas (CG2) by contacting, and a gas (CG3) containing carbon dioxide from which the ammonia is separated.

In addition, the sulfur oxide absorbent (S3) absorbing the ammonia in step (d) may be used as the sulfur oxide absorbent (S1) in step (a).

In addition, the absorption/separation method of the acidic gas may further include the step (e) of preparing ammonium sulfate by separating ammonium sulfate from the sulfur oxide absorbent (S3) absorbing the ammonia in step (d). .

In addition, one or more of the steps (a), (b) and (c) may be performed using a membrane contactor.

Further, the steps (a), (b) and (c) may be performed using a membrane contactor.

In addition, the membrane contactor may include at least one selected from the group consisting of polypropylene, polyethylene, polyester, polyamide, polyimide, polyvinyl chloride, polyurethane, and polypropylene oxide.

In addition, the sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH), sodium sulfite (Na ₂ SO ₃ ), water, potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), and may include at least one selected from the group consisting of a mixture thereof.

In addition, the sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH), sodium sulfite (Na ₂ SO ₃ ), potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), and may be an aqueous solution containing at least one selected from the group consisting of a mixture thereof at a molar concentration of 0.001M to 4M.

In addition, the carbon dioxide absorbent (C1) may include at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), amines, amino acids or salts thereof, and ionic liquids.

In addition, the carbon dioxide absorbent (C1) is at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), amines, amino acids or salts thereof, and ionic liquids in a concentration of 1 to 30 wt% It may be an aqueous solution containing.

According to another aspect of the present invention, in the acid gas absorption/separation apparatus for absorbing/separating sulfur oxides (SOx) and carbon dioxide (CO ₂ ) from exhaust gas, the acid gas absorption/separating apparatus 10 absorbs sulfur oxides Including / separation device 100 and carbon dioxide absorption / separation device 200,

The sulfur oxide absorption/separation device 100 receives the exhaust gas G1 from the upper side and the sulfur oxide absorber S1 from the lower side, and absorbs the sulfur oxide from the exhaust gas G1. ) To the upper side and the sulfur oxide absorption tower 120 for discharging the exhaust gas (G2) from which the sulfur oxide is separated to the lower side; including,

The carbon dioxide absorption/separation device 200 receives the exhaust gas G2 from the sulfur oxide absorption tower 120 from the upper side and the carbon dioxide absorbent C1 from the lower side, and absorbs carbon dioxide from the exhaust gas G2 A carbon dioxide absorption tower 220 for discharging one carbon dioxide absorbent (C2) to an upper portion and exhaust gas (G3) from which the carbon dioxide is separated to a lower portion; And a carbon dioxide absorbent from which the carbon dioxide absorbent (C2) is supplied to remove carbon dioxide from the carbon dioxide absorbent (C2) to discharge a gas containing carbon dioxide (CG1) to the upper side, and the gas containing carbon dioxide (CG1) is separated ( An acid gas absorption/separation apparatus 10 is provided that includes; a carbon dioxide stripping tower 230 for discharging C3) to the bottom.

In addition, the sulfur oxide absorption tower 120 may be connected to the carbon dioxide absorption tower 220 in series.

In addition, the acidic gas absorption/separation device 10 further includes an ammonia absorption/separation device 300, the ammonia absorption/separation device 300 includes an ammonia absorption tower 310, and the carbon dioxide The containing gas (CG1) additionally contains ammonia, and the ammonia absorption tower 310 receives the carbon dioxide and the gas containing ammonia (CG2) from the carbon dioxide stripping tower 230 from the top, and the sulfur oxide The absorbent (S2) is supplied from the bottom, the sulfur oxide absorbent (S3) absorbing the ammonia from the gas (CG2) is discharged to the upper portion, and the gas (CG3) containing carbon dioxide from which the ammonia is separated is discharged to the lower portion can do.

In addition, the sulfur oxide absorption/separation device 100 further includes a storage tank 110 for storing the sulfur oxide absorbent S1, and the sulfur oxide absorbent S1 stored in the storage tank 110 is converted into the sulfuric acid. It can be supplied to the lower portion of the cargo absorption tower 120.

In addition, the carbon dioxide absorbing/separating device 200 further includes a reboiler 210 storing the carbon dioxide absorbing agent C1, and the carbon dioxide absorbing agent C1 stored in the reboiler 210 It may be supplied to the lower portion of the carbon dioxide absorption tower 220.

In addition, the carbon dioxide absorption/separation device 200 may further include a chiller above the carbon dioxide stripping tower 230 to cool the top of the carbon dioxide stripping tower 230.

In addition, the carbon dioxide absorbing/separating device 200 further includes a pipe for supplying the carbon dioxide absorbent C1 to a lower portion of the carbon dioxide absorption tower 220, and the carbon dioxide absorbing agent ( A chiller for cooling C1) may be additionally included.

The present invention can provide a method and apparatus for absorbing/separating acid gas that can significantly reduce the volume of equipment and the installation site by using a small, highly efficient membrane contactor.

In addition, the acid gas absorption/separation method and apparatus of the present invention can selectively absorb and separate sulfur oxides and carbon dioxide from exhaust gas, and in particular, sulfur oxides are ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), that is, fertilizers as by-products. It has the effect of making it possible to recycle it.

1 is a schematic diagram schematically showing an acid gas absorption/separation apparatus of the present invention.
2 is a photograph of a membrane contactor used in a sulfur oxide absorption tower, a carbon dioxide absorption tower, or an ammonia absorption tower of the acid gas absorption/separation apparatus of the present invention.
3 is a graph showing the SO ₂ removal rate over time during the absorption of SO ₂ performed according to Examples 1 to 5. FIG.
4 is a graph using 3wt% aqueous ammonium hydroxide solution as a CO ₂ absorbent showing a CO ₂ removal rate of the CO ₂ absorption during the time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention.

However, the following description is not intended to limit the present invention to a specific embodiment, and in describing the present invention, when it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. .

The terms used herein are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, elements, or combinations thereof described in the specification, but one or more other features or It is to be understood that the possibility of the presence or addition of numbers, steps, actions, elements, or combinations thereof is not preliminarily excluded.

Hereinafter, an acid gas absorption/separation method for absorbing/separating sulfur oxide (SOx) and carbon dioxide (CO ₂ ) from the exhaust gas of the present invention will be described. At this time, x of sulfur oxide (SOx) is a real number determined according to the oxidation number of S.

first, Exhaust gas (G1) Sulfur oxide By contacting with the absorbent (S1) From flue gas (G1) Absorbing sulfur oxide (SOx) Sulfur oxide An absorbent (S2), and Sulfur oxide Separate Exhaust gas (G2) To prepare (step a).

The sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH), sodium sulfite (Na ₂ SO ₃ ) , Water, potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), and may include one or more selected from the group consisting of a mixture thereof, preferably may include ammonium hydroxide (NH ₄ OH) .

The mixture may be a mixture of hydrogen peroxide (H ₂ O ₂ ) and sodium hydroxide (NaOH).

In addition, according to another embodiment, the sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH) , Sodium sulfite (Na ₂ SO ₃ ), potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), and a mixture thereof, it may be an aqueous solution containing at least one selected from the group consisting of 0.001M to 4M molar concentration have.

Next, above Exhaust gas (G2) The carbon dioxide absorbent (C1) From flue gas (G2) Carbon dioxide (CO ₂ ) To prepare a carbon dioxide absorbent (C2) absorbing and the exhaust gas (G3) from which the carbon dioxide is separated (step b).

The carbon dioxide absorbent (C1) may include at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), an amine, an amino acid or a salt thereof, and an ionic liquid.

The amine may be monoethanolamine (MEA) or piperazine.

The amino acid may be glycine.

The ionic liquid may be 1-ethyl-3-methylimidazolium tetrafluoroborate.

In addition, according to another embodiment, the carbon dioxide absorbent (C1) is at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), an amine, an amino acid or a salt thereof, and an ionic liquid. It may be an aqueous solution containing in a concentration of 1 to 30wt%.

Next, carbon dioxide from the carbon dioxide absorbent (C2) Removed A carbon dioxide absorbent (C3) from which the gas containing carbon dioxide (CG1) and the gas containing carbon dioxide (CG1) are separated is prepared (step c).

The gas containing carbon dioxide (CG1) is a gas containing additional ammonia (CG2), and sulfuric acid which absorbs the ammonia from the gas (CG2) by contacting the gas (CG2) with the sulfur oxide absorbent (S2) It may further include a step (d) of producing a cargo absorbent (S3) and a gas (CG3) containing carbon dioxide from which the ammonia is separated.

In addition, the sulfur oxide absorbent (S3) absorbing the ammonia in step (d) may be used as the sulfur oxide absorbent (S1) in step (a).

In addition, the step (e) of preparing ammonium sulfate by separating ammonium sulfate from the sulfur oxide absorbent (S3) absorbing the ammonia in step (d) may be further included.

At least one of the steps (a), (b) and (c) may be performed using a membrane contactor.

In addition, according to another embodiment, the steps (a), (b) and (c) may be performed using a membrane contactor.

The membrane contactor may include at least one selected from the group consisting of polypropylene, polyethylene, polyester, polyamide, polyimide, polyvinyl chloride, polyurethane, and polypropylene oxide.

1 is a schematic diagram schematically showing an acid gas absorption/separation apparatus of the present invention. Hereinafter, an acid gas absorption/separation apparatus of the present invention will be described with reference to FIG. 1.

In the acid gas absorption/separation apparatus for absorbing/separating sulfur oxide (SOx) and carbon dioxide (CO ₂ ) from the exhaust gas of the present invention, the acid gas absorption/separation apparatus 10 is a sulfur oxide absorption/separation apparatus 100 And a carbon dioxide absorption/separation device 200,

The sulfur oxide absorption/separation device 100 receives the exhaust gas G1 from the upper side and the sulfur oxide absorber S1 from the lower side, and absorbs the sulfur oxide from the exhaust gas G1. ) To the upper side and the sulfur oxide absorption tower 120 for discharging the exhaust gas (G2) from which the sulfur oxide is separated to the lower side; including,

The carbon dioxide absorption/separation device 200 receives the exhaust gas G2 from the sulfur oxide absorption tower 120 from the upper side and the carbon dioxide absorbent C1 from the lower side, and absorbs carbon dioxide from the exhaust gas G2 A carbon dioxide absorption tower 220 for discharging one carbon dioxide absorbent (C2) to an upper portion and exhaust gas (G3) from which the carbon dioxide is separated to a lower portion; And a carbon dioxide absorbent from which the carbon dioxide absorbent (C2) is supplied to remove carbon dioxide from the carbon dioxide absorbent (C2) to discharge a gas containing carbon dioxide (CG1) to the upper side, and the gas containing carbon dioxide (CG1) is separated ( It may include a; carbon dioxide stripping tower 230 for discharging C3) to the bottom.

The sulfur oxide absorption tower 120 may be connected to the carbon dioxide absorption tower 220 in series.

The acid gas absorption/separation apparatus 10 further includes an ammonia absorption/separation apparatus 300, and the ammonia absorption/separation apparatus 300 includes an ammonia absorption tower 310, and includes the carbon dioxide. The gas (CG1) further contains ammonia,

The ammonia absorption tower 310 receives the gas (CG2) containing carbon dioxide and ammonia from the carbon dioxide stripping tower 230 from the upper side, the sulfur oxide absorbent (S2) is supplied from the lower side, the gas (CG2) ), the sulfur oxide absorbent S3 absorbing the ammonia may be discharged to the upper portion, and the gas CG3 including carbon dioxide from which the ammonia is separated may be discharged to the lower portion.

The sulfur oxide absorption/separation device 100 further includes a storage tank 110 for storing the sulfur oxide absorbent S1, and absorbs the sulfur oxide absorbent S1 stored in the storage tank 110 It can be supplied to the lower portion of the tower 120.

The carbon dioxide absorption/separation device 200 further includes a reboiler 210 for storing the carbon dioxide absorbent C1, and the carbon dioxide absorbent C1 stored in the reboiler 210 is transferred to the carbon dioxide absorption tower ( 220) can be supplied.

The carbon dioxide absorption/separation device 200 may further include a chiller above the carbon dioxide stripping tower 230 to cool the top of the carbon dioxide stripping tower 230.

The carbon dioxide absorption/separation device 200 further includes a pipe supplying the carbon dioxide absorbent (C1) under the carbon dioxide absorption tower 220, and the carbon dioxide absorbent (C1) on part or all of the pipe It may further include a chiller (Chiller) for cooling.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples. However, this is for illustrative purposes, and the scope of the present invention is not limited thereby.

Example 1

(a) sulfur dioxide (SO ₂ ) absorption

Referring to Figure 1, the sulfur dioxide absorption tower 120 at a flow rate of 100ml/min in an aqueous solution of 0.01M ammonium hydroxide (NH ₄ OH), which is a sulfur dioxide absorbent (S1) stored in a storage tank 110 at room temperature (20°C). It was injected into the shell side of the phosphorus hollow fiber membrane contactor.

The sulfur oxide absorption tower (G1) with a volume ratio of SO ₂ :CO ₂ :N ₂ =0.2%:15%:84.8% using a mass flow controller at ₂ L/min based on the flow rate of CO ₂ ( 120) was injected into the lumen side of the hollow fiber membrane contactor to prepare a sulfur oxide absorbent (S2) that absorbed SO ₂ from the exhaust gas (G1), and was moved to the upper portion of the sulfur oxide absorption tower 120.

(b) carbon dioxide (CO ₂ ) absorption

Referring to Figure 1, a carbon dioxide absorbent (C1) stored in the reboiler 210, a 3wt% ammonia aqueous ammonium hydroxide (NH ₄ OH) aqueous solution at a flow rate of 100ml / min 80 ℃ carbon dioxide absorption tower 220, a hollow fiber membrane It was injected into the shell side of the membrane contactor.

The exhaust gas (G2) from which the SO ₂ discharged from the sulfur oxide absorption tower 120 is separated is injected into the lumen side of the hollow fiber membrane contactor, which is the carbon dioxide absorption tower 220, and absorbs CO ₂ from the exhaust gas G2. One carbon dioxide absorbent (C2) was prepared and moved to the top of the carbon dioxide absorption tower 120.

(c) CO ₂ Separation

Referring to FIG. 1, the carbon dioxide absorbent (C2) is supplied to the carbon dioxide stripping tower 230 and heated to 80° C. to remove carbon dioxide from the carbon dioxide absorbent (C2) to remove the carbon dioxide-containing gas (CG1). It was moved to the top of the tower 230. Here, a chiller was installed outside the upper portion of the carbon dioxide stripping tower 230, and the temperature of the chiller was set to 20°C.

In addition, the carbon dioxide absorbent (C3) from which the gas containing carbon dioxide (CG1) is separated is moved to the lower portion of the carbon dioxide stripping tower (230), moved to the reboiler (210) and stored. The carbon dioxide absorbent (C3) stored in the reboiler 210 is supplied to the lower portion of the carbon dioxide absorption tower 220 to be used as a carbon dioxide absorbent (C1), and the temperature of the reboiler 210 is set to 80°C. Thus, the carbon dioxide absorbent (C3) can be heated. Here, a chiller may be installed in the supply pipe before being supplied to the carbon dioxide absorption tower 220, and the temperature of the chiller may be set to 20°C.

(d) carbon dioxide and ammonia recovery

Referring to FIG. 1, a sulfur oxide absorbent (S2) discharged from the upper portion of the sulfur oxide absorption tower 120 was injected into the shell side of a hollow fiber membrane contactor, which is an ammonia absorption tower 310.

Gas (CG2) including carbon dioxide and ammonia discharged from the carbon dioxide stripping tower 230 is injected into the lumen side of the hollow fiber membrane contactor, which is the ammonia absorption tower 310, and absorbs the ammonia from the gas (CG2). One sulfur oxide absorbent (S3) was moved to the upper portion of the ammonia absorption tower 310, discharged, and stored in the storage tank 110. The ammonia-separated carbon dioxide-containing gas (CG3) was moved to the lower portion of the ammonia absorption tower 310 and moved to an external carbon dioxide tank (not shown) for storage, and the purity of carbon dioxide in the gas (CG3) was It was more than 95wt%.

The sulfur oxide absorbent S3 stored in the storage tank 110 may be supplied to the lower portion of the sulfur oxide absorption tower 120 to be used as a sulfur oxide absorbent S1.

Example 2

In the sulfur dioxide absorption (a), it was carried out in the same manner as in Example 1, except that 0.01M sodium carbonate (NaHCO ₃ ) aqueous solution was used instead of using 0.01M aqueous ammonium hydroxide (NH ₄ OH) aqueous solution as the sulfur oxide absorber. Became.

Example 3

In the sulfur dioxide absorption (a), the same as in Example 1, except that 0.01M sodium sulfite (Na ₂ SO ₃ ) aqueous solution was used instead of using 0.01M aqueous ammonia aqueous ammonium hydroxide (NH ₄ OH) as the sulfur oxide absorber. Was done by the method.

Example 4

In the sulfur dioxide absorption (a), it was carried out in the same manner as in Example 1, except that water was used instead of an aqueous solution of ammonium hydroxide (NH ₄ OH), which is 0.01M aqueous ammonia as the sulfur oxide absorber.

Example 5

In the sulfur dioxide absorption (a), it was carried out in the same manner as in Example 1, except that 0.01M aqueous sodium hydroxide (NaOH) solution was used instead of using 0.01M aqueous ammonium hydroxide (NH ₄ OH) aqueous solution as the sulfur oxide absorber. Became.

Table 1 below summarizes the types of sulfur oxide absorbents and carbon dioxide absorbents used in Examples 1 to 5.

Sulfur oxide absorbent Carbon dioxide absorbent Example 1 0.01M ammonium hydroxide (NH ₄ OH) aqueous solution 3wt% ammonium hydroxide (NH ₄ OH) aqueous solution Example 2 0.01M sodium carbonate (NaHCO ₃ ) aqueous solution 3wt% ammonium hydroxide (NH ₄ OH) aqueous solution Example 3 0.01M sodium sulfite (Na ₂ SO ₃ ) aqueous solution 3wt% ammonium hydroxide (NH ₄ OH) aqueous solution Example 4 water 3wt% ammonium hydroxide (NH ₄ OH) aqueous solution Example 5 0.01M sodium hydroxide (NaOH) aqueous solution 3wt% ammonium hydroxide (NH ₄ OH) aqueous solution

[Test Example]

Test Example 1: SO ₂ SO depending on the type of absorbent ₂ Removal rate

The SO ₂ removal rate of the SO ₂ absorber types were measured. The specifications of the membrane contactor for testing the performance of the SO ₂ absorbent are shown in Table 2, and the photograph of the membrane contactor is shown in FIG. 2.

Kinds value External diameter of hollow fiber (μm) 840 Hollow fiber inner diameter (μm) 600 Hollow fiber porosity (%) 67 Hollow fiber length (mm) 270 Number of hollow fibers 100 Average pore size (μm) 0.15 Module packing density (%) 45

After 20 minutes, 40 minutes, and 60 minutes from the time when the SO ₂ absorbent is introduced into the sulfur oxide absorption tower 120, the SO ₂ removal rate (%) was calculated by the following calculation equation 1 and shown in Table 3 and FIG.

[Calculation 1]

SO ₂ removal rate (%)= ((S ₁ -S ₂ )/S ₁ )x100

SO ₂ in the above formula _1, S 1 is an SO ₂ concentration in the exhaust gas (G1) introduced into Lumen side of the membrane contactor sulfur oxide absorber (120), S ₂ is the exhaust gas (G2) discharged from the membrane contactor Is the concentration of

Time (minutes) Example 1 Example 2 Example 3 Example 4 Example 5 20 99.93 99.385 99.7 55.89 99.76 40 98.745 95.885 75.135 44.56 96.745 60 95.46 90.53 68.99 37.98 83.05

Referring to Table 3 and FIG. 3, it was confirmed that the SO ₂ removal rate of Example 1 using a 0.01M ammonium hydroxide (NH ₄ OH) aqueous solution as a sulfur oxide absorber was the best. Ammonium hydroxide was selected as the absorbent for the fertilizer production process, but it shows a higher removal rate than other absorbents, so it can be said to be an excellent absorbent for removing sulfur oxides.

Test Example 2: Analysis of carbon dioxide removal rate

Calculating a 3wt% aqueous ammonia in CO ₂ removal rates after 20 minutes, 40 minutes, 60 minutes from the time that is input to the CO ₂ absorber is carbon dioxide absorption tower 220 by using aqueous ammonium hydroxide solution as a CO ₂ absorbent (%) by following Formula 2 And shown in FIG. 4.

[Calculation 2]

CO ₂ removal rate (%)= ((C ₁ -C ₂ )/C ₁ )x100

In the above calculation formula 2, C ₁ is the concentration of CO ₂ in the exhaust gas G2 introduced into the Lumen side of the membrane contactor, which is the carbon dioxide absorption tower 220, and C ₂ is the CO ₂ in the exhaust gas G3 discharged from the membrane contactor. Concentration.

Referring to FIG. 4, the CO ₂ removal rate was 79.8% in 20 minutes, 77.067% in 40 minutes, and 77.267% in 60 minutes, and a constant CO ₂ removal rate was maintained when using an aqueous ammonium hydroxide solution of 3 wt% aqueous ammonia as a CO ₂ absorber. I could confirm that.

Test Example 3: Effect test by adding ammonia absorption tower

Since ammonia is highly volatile, the volatilization loss is large even at room temperature, but in the case of Examples 1 to 5, it was confirmed that almost no volatilization loss occurred as a result of volume measurement of the absorbent solution after the end of the test despite the long operation.

In the above, preferred embodiments of the present invention have been described, but those of ordinary skill in the relevant technical field can add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. Various modifications and changes may be made to the present invention by addition or the like, and it will be said that this is also included within the scope of the present invention. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

10: acid gas absorption/separation device
100: sulfur oxide absorption/separation device
110: storage tank
120: sulfur oxide absorption tower
200: carbon dioxide absorption/separation device
210: reboiler
220: carbon dioxide absorption tower
230: carbon dioxide stripping tower
300: ammonia absorption/separation device
310: ammonia absorption tower

Claims (18)

(a) a sulfur oxide absorbent (S2) in which sulfur oxide (SOx) is absorbed from the exhaust gas (G1) by contacting the exhaust gas (G1) with a sulfur oxide absorbent (S1), and an exhaust gas (G2) from which the sulfur oxide is separated. Manufacturing steps;
(b) preparing a carbon dioxide absorbent (C2) absorbing carbon dioxide (CO ₂ ) from the exhaust gas (G2) by contacting the exhaust gas (G2) with a carbon dioxide absorbent (C1), and an exhaust gas (G3) from which the carbon dioxide is separated step; And
(c) preparing a carbon dioxide absorbent (C3) from which a gas containing carbon dioxide (CG1) and a gas containing carbon dioxide (CG1) are separated by removing carbon dioxide from the carbon dioxide absorbent (C2);
Absorption/separation method of containing acid gas. The method of claim 1,
The absorption/separation method of the acid gas
The gas containing carbon dioxide (CG1) is a gas additionally containing ammonia (CG2),
(d) a gas (CG3) comprising a sulfur oxide absorbent (S3) in which the gas (CG2) is brought into contact with the sulfur oxide absorbent (S2) to absorb the ammonia from the gas (CG2), and carbon dioxide from which the ammonia is separated. ) Producing a; absorption/separation method of acid gas, characterized in that it further comprises. The method of claim 2,
The absorption/separation method of acid gas, characterized in that the sulfur oxide absorbent (S3) absorbing the ammonia in step (d) is used as the sulfur oxide absorbent (S1) in step (a). The method of claim 2,
The absorption/separation method of the acid gas
The absorption/separation method of acid gas, characterized in that it further comprises the step (e) of preparing ammonium sulfate by separating ammonium sulfate from the sulfur oxide absorbent (S3) absorbing the ammonia in step (d). The method of claim 1,
At least one of the steps (a), (b) and (c) is carried out using a membrane contactor. The method of claim 1,
Steps (a), (b) and (c) are carried out using a membrane contactor. The method of claim 5,
Absorption/separation method of acid gas, characterized in that the membrane contactor comprises at least one selected from the group consisting of polypropylene, polyethylene, polyester, polyamide, polyimide, polyvinyl chloride, polyurethane and polypropylene oxide . The method of claim 1,
The sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH), sodium sulfite (Na ₂ SO ₃ ) , Water, potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), and absorption/separation method of an acidic gas, characterized in that it comprises at least one selected from the group consisting of a mixture thereof. The method of claim 1,
The sulfur oxide absorbent (S1) is ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium carbonate (NaHCO ₃ ), sodium hydroxide (NaOH), sodium sulfite (Na ₂ SO ₃ ) , Potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ) and a mixture thereof, and absorption/separation of acid gas, characterized in that it is an aqueous solution containing at least one selected from the group consisting of 0.001M to 4M molar concentration Way. The method of claim 1,
The carbon dioxide absorbent (C1) is an acidic gas, characterized in that it contains at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), amine, amino acid or salt thereof, and ionic liquid. Absorption/separation method. The method of claim 1,
The carbon dioxide absorbent (C1) contains at least one selected from the group consisting of ammonium hydroxide (NH ₄ OH), ammonia (NH ₃ ), amines, amino acids or salts thereof, and ionic liquids in a concentration of 1 to 30 wt% Acid gas absorption/separation method, characterized in that it is an aqueous solution. In the acid gas absorption/separation apparatus for absorbing/separating sulfur oxides (SOx) and carbon dioxide (CO ₂ ) from exhaust gas,
The acid gas absorption/separation apparatus 10 includes a sulfur oxide absorption/separation apparatus 100 and a carbon dioxide absorption/separation apparatus 200,
The sulfur oxide absorption/separation device 100
The exhaust gas (G1) is supplied from the top, the sulfur oxide absorbent (S1) is supplied from the bottom, the sulfur oxide absorbent (S2) absorbing the sulfur oxide from the exhaust gas (G1) is discharged to the top, and the sulfur oxide is separated. Including; sulfur oxide absorption tower 120 for discharging the exhaust gas (G2) to the bottom,
The carbon dioxide absorption/separation device 200
The exhaust gas (G2) is supplied from the upper side from the sulfur oxide absorption tower (120), the carbon dioxide absorbent (C1) is supplied from the lower side, and the carbon dioxide absorbent (C2) absorbing carbon dioxide from the exhaust gas (G2) is discharged to the upper side. A carbon dioxide absorption tower 220 for discharging the exhaust gas G3 from which the carbon dioxide is separated; And
The carbon dioxide absorbent (C3) from which the carbon dioxide absorbent (C2) is supplied to remove carbon dioxide from the carbon dioxide absorbent (C2) to discharge a gas containing carbon dioxide (CG1) to the upper side, and the gas containing carbon dioxide (CG1) is separated The acid gas absorption/separation device (10) that includes; The method of claim 12,
Acid gas absorption/separation apparatus (10), characterized in that the sulfur oxide absorption tower (120) is connected in series with the carbon dioxide absorption tower (220). The method of claim 12,
The acid gas absorption/separation device 10 further includes an ammonia absorption/separation device 300,
The ammonia absorption/separation device 300 includes an ammonia absorption tower 310,
The gas containing carbon dioxide (CG1) further contains ammonia,
The ammonia absorption tower 310 receives the gas (CG2) containing carbon dioxide and ammonia from the carbon dioxide stripping tower 230 from the upper side, the sulfur oxide absorbent (S2) is supplied from the lower side, the gas (CG2) ) Discharging the sulfur oxide absorbent (S3) absorbing the ammonia from the upper side, and discharging the gas (CG3) containing carbon dioxide from which the ammonia is separated from the lower side. The method of claim 12,
The sulfur oxide absorption/separation device 100 further includes a storage tank 110 for storing the sulfur oxide absorbent S1,
Acid gas absorption/separation apparatus, characterized in that supplying the sulfur oxide absorbent (S1) stored in the storage tank (110) to the lower portion of the sulfur oxide absorption tower (120). The method of claim 12,
The carbon dioxide absorption/separation device 200 further includes a reboiler 210 for storing the carbon dioxide absorbent C1,
Acid gas absorption/separation apparatus, characterized in that for supplying the carbon dioxide absorbent (C1) stored in the reboiler (210) to a lower portion of the carbon dioxide absorption tower (220). The method of claim 12,
The carbon dioxide absorption/separation device 200 further includes a chiller at the top of the carbon dioxide stripping tower 230 to cool the top of the carbon dioxide stripping tower 230. Separation device. The method of claim 12,
The carbon dioxide absorption/separation device 200 further includes a pipe supplying the carbon dioxide absorbent C1 to a lower portion of the carbon dioxide absorption tower 220,
An acid gas absorption/separation device, characterized in that it further comprises a chiller for cooling the carbon dioxide absorbent (C1) on part or all of the pipe.

Images