KR100779618B1 - Apparatus and methode of co2 absorption from flue gas by double vortex tube - Google Patents

Abstract

An apparatus and a method for sucking and removing carbon dioxide are provided to reduce the size of the apparatus and improve the efficiency in suction of carbon dioxide, by using a two-stage vortex tube instead of a suction tower. A first vortex tube(200) exhausts a first suction liquid-mixed exhaust gas generated by mixing suction liquid and exhaust gas. A second vortex tube(300) receives the first suction liquid-mixed exhaust gas to generate a second suction liquid-mixed exhaust gas, and exhausts the second suction liquid-mixed exhaust gas. A suction liquid recovering tank(400) preliminarily stores the second suction liquid-mixed exhaust gas to emit purified gas where carbon dioxide is removed, and collects the suction liquid sucking carbon dioxide. A reproduction tower(160) receives the suction liquid sucking carbon dioxide, and separate the suction liquid sucking carbon dioxide into the carbon dioxide and the suction liquid to discharge the suction liquid and the carbon dioxide.

Description

Apparatus and method of CO2 absorption from flue gas by double vortex tube}

1 is a block diagram showing a CO ₂ absorption removal device using a conventional absorption tower,

2 is a block diagram of a CO ₂ absorption removal apparatus using a two-stage vortex tube according to an embodiment of the present invention,

3 is a schematic diagram showing a process of forming a vortex in the first and second vortex tubes according to the present invention,

4 is a perspective view of a first vortex tube configured to separately supply exhaust gas and absorbent liquid according to the present invention;

5 is a perspective view of a first vortex tube configured to supply exhaust gas and absorbent liquid to the same position according to the present invention.

Description of the main symbols in the drawings

100: absorption tower 120: purified gas

140: Fill

150: regeneration tower 160: storage tank

200: first vortex 300: second vortex

110, 210: flue gas 220: flue gas inlet

230: vortex rotary chamber 231: rotary chamber entrance

240: reaction unit 250: control valve

260: exhaust port 270: exhaust gas outlet

271: primary absorption liquid mixed exhaust gas 130, 280: absorption liquid

371: secondary absorption liquid mixed exhaust gas

400: absorbent liquid recovery tank

T1: Absorbent Storage Tank

P1, P2: Pump

The present invention relates to a CO ₂ absorption removal method using a vortex tube, and more particularly, to a size of a device for removing CO ₂ by removing CO ₂ by mixing an absorbent liquid and an exhaust gas using a two-stage vortex tube. The present invention relates to a CO ₂ absorption removal apparatus using a two-stage vortex tube and a method for minimizing the size, reducing the consumption of the absorbent liquid, and improving the absorption efficiency.

In general, carbon dioxide from the burning of fossil fuels is a major cause of the greenhouse effect that prevents the release of heat from the sun to the atmosphere when released into the atmosphere.

Therefore, many methods of separating and recovering carbon dioxide from exhaust gas and storing or immobilizing it in a concentrated state have been researched and developed. Adsorption, absorption, and membrane separation methods have been developed for separating and recovering carbon dioxide from exhaust gas.

The adsorption method is difficult to commercialize because it requires a lot of energy consumed in large capacity and process operation, and the membrane separation method is a method that can be used for energy saving process or small size, so it is difficult to use for large-scale exhaust gas discharge device.

On the other hand, the absorption method has already succeeded in the completion and commercialization of technology for decades, and is being used to remove carbon dioxide generated from oil and natural gas processing processes, and thousands of units are currently in operation. However, the absorption method has a problem that the economic efficiency depends very much on the type of absorbent liquid.

Representative carbon dioxide absorbents are the most commercially available amine compounds at present.

1 is a view showing a typical process of a conventional CO ₂ absorption method using an amine-based absorbing solution.

As shown in FIG. 1, the exhaust gas 110 including carbon dioxide is blown under the absorption tower 100, and the absorption liquid 130 is supplied above the absorption tower. In the absorption tower, a filler 140 having a large surface area is charged to improve the contact area between the exhaust gas and the absorbent liquid in the absorption tower, and thus, the counter current, that is, the gas flowing in the opposite direction and the liquid contact each other to improve the absorption rate. Absorption liquid containing carbon dioxide is separated only from the carbon dioxide in the regeneration tower 150, the separated carbon dioxide 170 is pressure-cooled and stored in the storage tank 160 in the liquid phase. Then, the regenerated absorbent liquid 130 is repeatedly sent to the absorption tower 100. At this time, the purified gas 120 from which carbon dioxide is removed is discharged to the upper portion of the absorption tower.

However, the packed tower absorption method has a disadvantage in that the size of the absorption tower increases, and the cost of the absorbent liquid is increased by using a lot of the absorbent liquid, and in particular, it requires a lot of energy consumption in regenerating the absorbent liquid, thereby increasing the overall operating cost.

Accordingly, the present invention is to solve the problems of the prior art described above, to install the vortex tube in two stages to apply a two-stage vortex tube in place of the suction stop to improve the exhaust gas suction rate of the absorbent liquid. CO ₂ absorption using two-stage vortex tubes to reduce the size of carbon dioxide absorbers, improve the absorption efficiency, reduce the amount of absorbent used to remove carbon dioxide, and reduce the cost of absorbent feed and energy spent on regeneration of absorbent. It is an object of the present invention to provide a removal device and a method thereof.

An apparatus for removing CO ₂ using a two-stage vortex tube of the present invention for achieving the above object includes: a first vortex tube for discharging a primary absorbent liquid mixed exhaust gas into which exhaust gas and absorbent liquid are introduced; A second vortex tube into which the first absorbent liquid mixed exhaust gas of the first vortex tube flows in and discharges the second mixed absorbent liquid mixed exhaust gas; An absorbent liquid recovery tank configured to temporarily store the secondary absorbent liquid mixed exhaust gas of the second vortex tube to discharge the purified gas from which CO ₂ has been removed, and collect the absorbent liquid absorbing CO ₂ ; And a regeneration tower for separating and discharging the CO ₂ and the absorbent liquid after receiving the absorbent liquid absorbing the CO ₂ of the absorbent liquid recovery tank.

The first vortex tube is characterized in that the inlet of the exhaust gas and the absorption liquid is configured to be separated.

The first vortex tube is characterized in that the inlet of the exhaust gas and the absorption liquid is configured in the same position.

The regeneration tower further comprises an absorbent liquid storage tank for storing and replenishing the absorbent liquid.

CO ₂ absorption removal method using a two-stage vortex tube of the present invention for achieving the above object, the two-stage vortex tube, by mixing the exhaust gas and the absorbent liquid containing CO ₂ into the first vortex tube 1 A primary absorption process of forming and discharging the primary absorption liquid mixed exhaust gas; A second absorption process of receiving the first absorption liquid mixed exhaust gas of the first absorption process into a second vortex tube to form and discharge the second absorption liquid mixed exhaust gas; An absorbent liquid recovery process of separating the purified gas from the secondary absorbent liquid mixed exhaust gas discharged in the second absorption process and recovering the absorbent liquid; It characterized in that it comprises an absorbent liquid collection process for collecting so that the absorbent liquid can be reused by separating and storing the CO ₂ from the absorbent liquid.

The first absorption process may be performed by introducing the exhaust gas and the absorbent liquid at the same position of the first vortex tube.

The first absorption process may be performed by introducing the exhaust gas and the absorbent liquid at different positions of the first vortex tube.

The present invention having the above-described configuration utilizes a first vortex tube and a second vortex tube as an absorption tower to generate a vortex by injecting a combustion exhaust gas and a CO ₂ absorbent liquid in a cocurrent flow into the first vortex tube. performing a first absorption of CO ₂ by having, by forming a vortex in the back after the second vortex tube sikimyeo significantly improved the absorption rate of CO ₂ by performing a number of second intake of CO _2, CO ₂ gas By absorbing the absorbent absorbed liquid into the collected CO ₂ gas and the absorbent liquid to reuse the absorbent liquid, the size of the carbon dioxide absorbing apparatus is reduced, the absorption efficiency is improved, the amount of absorbent liquid is reduced when removing carbon dioxide, the absorbent liquid supply cost and It is possible to reduce the energy cost of absorbing liquid regeneration.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 2 is a view of the configuration of the second stage in accordance with one embodiment of the present invention the vortex tube to remove the CO ₂ absorbent by using an apparatus (hereinafter referred to as "CO ₂ absorption removal device").

As shown in FIG. 2, the CO ₂ absorption removal apparatus of the present invention includes two stages of the first and second vortex tubes 200 and 300 instead of the absorption tower 100 of the prior art. The absorbent liquid recovery tank 400 is provided at the outlet of the second vortex tube 300, and after the purified gas is discharged from the absorbent liquid recovery tank 400, the absorbent liquid absorbing carbon dioxide is recovered. And the regeneration tower 160 is disposed on the outlet side of the absorbent liquid recovery tank 400 is configured to recover the absorbent liquid to be reused by separating and storing carbon dioxide from the absorbent liquid. The recovered absorbent liquid is stored in the absorbent liquid storage tank T1 to enable the supply and replenishment of the absorbent liquid.

In the CO ₂ absorption removal device having the above-described configuration, the exhaust gas 210 and the absorbent liquid 280 flow into the first vortex tube 200 to form a vortex to refine the droplet of the absorbent liquid to form CO _2. After mixing with the exhaust gas in a state in which the contact area with the wider contact area is expanded, the mixture becomes a primary absorbing liquid mixed gas 271, and then flows into the second vortex tube 300 to be remixed to form a secondary absorbing liquid mixed gas 371. By this mixing process, the absorption rate of CO ₂ in the exhaust gas 210 by the absorbent liquid 280 is remarkably improved, thereby miniaturizing the CO ₂ absorption removal apparatus, reducing the consumption of the absorbent liquid, and reducing operating costs. To do it.

FIG. 3 is a schematic diagram illustrating a process of forming a vortex in a first vortex tube according to the present invention. The function of the first vortex tube 200 will be described in more detail with reference to FIG. 3.

As shown in FIG. 3, the first vortex tube 200 communicates with the exhaust gas inlet 220 through which the exhaust gas 210 is injected in a direction orthogonal to the vortex rotation chamber 230, and the vortex rotation chamber. 230 communicates with the reaction unit 240 in the form of a cylinder. At the end of the reaction unit 240 is provided a conical control valve 250 that can be moved back and forth to adjust the size of the exhaust port 260, the cone is installed in the direction toward the vortex rotating chamber 230. The exhaust gas outlet 270 is formed at the end of the vortex rotating chamber in the opposite direction.

At this time, the vortex rotating chamber inlet 231 to which the exhaust gas 210 and the absorbing liquid 280 are supplied is formed to have a smaller diameter than the exhaust gas inlet 220, and the exhaust gas outlet 270 is in contact with the vortex rotating chamber 230. It is formed in a conical shape so that the diameter of the direction toward the outside becomes larger.

The CO ₂ absorption method by the first vortex tube 200 having the configuration as described above is performed as follows.

The exhaust gas 210 including the CO ₂ is injected at a high pressure into the inlet 220 of the vortex tube 200 at a pressure of 3 to 10 atm using a compressor. At this time, the absorption liquid 280 is co-currently supplied with the exhaust gas 210, that is, in the same direction.

In this case, the simultaneous supply method of the absorbent liquid 280 is a method of supplying from a separate inlet, there is a method of supplying through the inlet of the same position.

4 is a perspective view of a first vortex tube configured to supply exhaust gas and absorbent liquid separately according to the present invention, and FIG. 5 is a perspective view of a first vortex tube configured to supply exhaust gas and absorbent liquid according to the present invention to the same position. to be.

In the case of FIG. 4, the exhaust gas inlet 220 and the absorbent liquid inlet 280a are formed at different positions. In the case of FIG. 5, the exhaust gas and the absorbent liquid are simultaneously introduced into the vortex rotating chamber 230. An absorbent liquid inlet 280a is formed at the side of the.

Absorbents that can be used in the carbon dioxide absorption removal apparatus as described above are monoethanolamine (MEA, Monoethanolamine), methyldiethanolamine (MDEA, Methyldiethanolamine), diethanolamine (DEA, diethanolamine), tertiary amine, K ₂ CO ₃ , NH _3, and the like, and monoethanolamine (hereinafter referred to as MEA) was used in the present invention.

The absorbed liquid 280 is mixed with the high-pressure injected flue gas 210 and supplied back to the vortex rotating chamber 230 in the first vortex tube. The exhaust gas 210 and the absorbing liquid 280 injected into the vortex rotating chamber 230 form a strong vortex while rotating the inside of the rotating chamber. At this time, due to the strong vortex of the exhaust gas 210 formed, droplets of the absorbing liquid 280 are finely dispersed. Since the specific surface area of the finely dispersed absorbent liquid 280 increases more rapidly than when the droplet is large, the contact area with the exhaust gas 210 is widened, and even when the same amount of the absorbent liquid is used, the absorbed liquid 280 with the exhaust gas 210 is increased. The reaction effect is further increased and the absorption rate of carbon dioxide is significantly increased. At this time, the gas including the absorbent liquid droplets generated and discharged is referred to as a primary absorbent liquid mixed gas 271.

The exhaust gas 210 and the liquid droplets 280 in which the vortex forms a strong vortex are finely rotated in the reaction part 240 in a vortex shape, and carbon dioxide is absorbed in the absorption liquid 280 and simultaneously compressed. In this case, the chemical formula of MEA used as the absorbent liquid 280 is as follows.

Structure of MEA: NH ₂ -CH ₂ -CH ₂ -OH (hereinafter referred to as RNH ₂ )

In addition, the reaction between the carbon dioxide and the absorbent liquid 280 in the exhaust gas 210 takes place in three forms as follows.

2RNH ₂ + CO ₂ = (RNH ₃ ) ⁺ + (RNHCOO) ^-

_{2RNH 2 + CO 2 + H 2} O = 2 (RNH 3) + + CO 3 2 -

_{^{2RNH 3 + · CO 3 2 -}} + CO 2 + H 2 0 = 2RNH 3 + + 2HCO 3 -

At this time, due to the difference in the constant temperature in the radial direction during the rotation in the reaction unit 240, the temperature is increased because the compression is at a high pressure in the peripheral portion, the temperature is lowered because the pressure is lowered in the central part.

If the cone-shaped control valve 250 is moved forward, the area of the exhaust port 260 is narrowed, it is installed to have a structure that is moved back and widened. The vortices cause an absorption reaction and move up to the control valve 250, in which the gas flows back through the exhaust gas outlet 270 back to the center of the reaction unit 240, which includes the absorption liquid droplets reacted with carbon dioxide in the control valve and cooled and condensed. The absorbed liquid mixed exhaust gas 271 is discharged and the remaining hot exhaust gas is discharged to the exhaust port 260 generated around the control valve 250. In the embodiment of the present invention, the control valve 250 is completely moved forward so that the exhaust port 260 is not formed.

The first absorption liquid mixed exhaust gas 271 discharged from the first vortex tube 200 flows back into the second vortex tube 300. Unlike the first vortex tube 200 of FIG. 3, the second vortex tube 300 except that only the inlet through which the first absorbent liquid exhaust gas 271 discharged from the first vortex tube 200 flows is formed. Since it is the same as the structure of the first vortex tube 200, a detailed description thereof will be omitted. That is, the first absorbent liquid mixed exhaust gas 271 introduced into the second vortex tube 300 reacts with the absorbent liquid and carbon dioxide by the same process as in the first vortex tube 300, and condenses to exhaust gas outlet 270. ) Is discharged to the secondary absorbing liquid mixed exhaust gas 371 further removed carbon dioxide. The discharged secondary absorption liquid mixed gas 371 is recovered, and the exhaust gas excluding carbon dioxide is discharged to the atmosphere or purified through a separate treatment device.

At this time, as the control valve 250 inside the vortex tubes 200 and 300 is moved forward to narrow the area of the exhaust port 260, the temperature of the absorbing liquid and the exhaust gas discharged to the exhaust gas outlet is lowered. 260) was completely closed to maximize the condensation effect.

The cooling and condensation mechanisms and effects in the vortex tubes 200 and 300, the discharge process to the exhaust gas outlet, etc. are known empirically by experiment, but the principle is not clearly defined at present.

The absorbent liquid 280 discharged to the exhaust gas outlet 270 includes carbon dioxide, which is separately recovered and recycled by separating the carbon dioxide through the regeneration tower 150 and supplied back into the vortex tube 200. You will go through the process. In addition, the separated carbon dioxide is stored in a separate storage tank 160 at this time.

<Example 1>

When exhaust gas with 12% carbon dioxide is supplied to the vortex tube with exhaust gas using monoethanolamine having a concentration of 20% as the absorbent liquid, gas and liquid ratios are supplied while supplying gas and liquid from separate inlets as shown in Fig. As a result of the absorption test with the change of, the absorption rate was 28% at 450 gas / liquid ratio and then 70% after passing through the vortex tube in two stages.

<Example 2>

Using the exhaust gas of Example 1 as shown in Fig. 5, the gas and liquid ratios of the gas and liquid experiments while varying the gas and liquid ratios while supplying the gas and liquid at the same supply position are 38%.

This flue gas was passed through a two-stage vortex tube and showed an 80% absorption rate.

Comparative Example 1

In the absorption tower using the exhaust gas of Example 1, a 20% solution of monoethanol amine was supplied to the upper part of the tower and the exhaust gas having the same composition as that of Example 1 was supplied to the lower part of the absorption tower so that the gas and liquid ratio was 35. % And the absorption ratio was about 35% when the gas and liquid ratio were set to 100.

In Examples 1 and 2, the amount of the absorbent liquid used was reduced by about 80% or more compared with Comparative Example 1.

As described above, the apparatus and method for CO ₂ absorption removal using a vortex tube according to the present invention is a method of absorbing and removing carbon dioxide contained in exhaust gas using one vortex tube as an absorption tower. Compared with the two vortex tubes, it was possible to reduce carbon dioxide and reduce carbon dioxide, reduce the size of carbon dioxide absorber and improve absorption efficiency. Compared to the absorption tower method, it can reduce the absorbing liquid by more than 80% and removes more than twice as much carbon dioxide than using one vortex tube.

Claims (6)

A first vortex tube into which the exhaust gas and the absorbent liquid are introduced to discharge the mixed primary absorbent liquid mixed exhaust gas; A second vortex tube into which the first absorbent liquid mixed exhaust gas of the first vortex tube flows in and discharges the second mixed absorbent liquid mixed exhaust gas; An absorbent liquid recovery tank configured to temporarily store the secondary absorbent liquid mixed exhaust gas of the second vortex tube to discharge the purified gas from which CO ₂ has been removed, and collect the absorbent liquid absorbing CO ₂ ; And a regeneration tower for separating and discharging the CO ₂ and the absorbent liquid after receiving the absorbent liquid that absorbs the CO ₂ of the absorbent liquid recovery tank. ₂ . The method of claim 1, wherein the first vortex tube is a carbon dioxide absorption removal device using a two-stage vortex tube, characterized in that the inlet of the exhaust gas and the absorption liquid is separated. The apparatus of claim 1, wherein the first vortex tube is configured to have an inlet of exhaust gas and an absorbent liquid at the same position. A first absorption process of injecting and mixing the flue gas containing CO ₂ into the first vortex tube to form and discharge the first absorbent liquid mixed flue gas; A second absorption process of receiving the first absorption liquid mixed exhaust gas of the first absorption process into a second vortex tube to form and discharge the second absorption liquid mixed exhaust gas; An absorbent liquid recovery process of separating the purified gas from the secondary absorbent liquid mixed exhaust gas discharged in the second absorption process and recovering the absorbent liquid; Carbon dioxide absorption removal method using a two-stage vortex tube, characterized in that it comprises a process for collecting the absorbent liquid so that the absorbent liquid can be reused by separating and storing the CO ₂ from the absorbent liquid. The method of claim 4, wherein the first absorption process is performed by introducing the exhaust gas and the absorption liquid at the same position of the first vortex tube. The method of claim 4, wherein the first absorption process is performed by introducing the exhaust gas and the absorbent liquid at different positions of the first vortex tube.

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