KR102562971B1 - Carbon dioxide absorbent and manufacturing process thereof - Google Patents

Abstract

The present invention relates to a carbon dioxide absorbent and a manufacturing method thereof, and more particularly, to a carbon dioxide absorbent capable of greatly reducing renewable energy in the process of capturing carbon dioxide and consuming less energy because ammonia water can be reused, and a manufacturing method thereof. .
The present invention is a reaction step (S10) of reacting by introducing ammonia water and ethylene oxide into the reactor (11); An ammonia removal step (S20) of removing unreacted ammonia in the reaction step (S10) using an ammonia separation tower (13); A water removal step (S30) of concentrating using an evaporator (14a) and removing water using an evaporation tower (14b); a first carbon dioxide absorbent manufacturing step (S40) utilizing the bottom liquid of the evaporator (14a); and a second carbon dioxide absorbent manufacturing step (S50) of adding other components to the first carbon dioxide absorbent according to the composition of the exhaust gas.

Description

Carbon dioxide absorbent and manufacturing process thereof {Carbon dioxide absorbent and manufacturing process thereof}

The present invention relates to a carbon dioxide absorbent and a manufacturing process thereof, and more particularly, to a carbon dioxide absorbent capable of greatly reducing renewable energy in the process of capturing carbon dioxide and reusing ammonia water, which requires less energy to manufacture the absorbent, and a manufacturing process thereof is about

Due to global warming, the frequency of occurrence of abnormal weather phenomena such as heat waves, heavy snowfalls, typhoons, forest fires, and droughts is increasing, and thus climate problems are becoming serious all over the world. The international community adopted the 'Kyoto Protocol' in 1997 to solve the problem of climate change, and is making active efforts such as adopting the 'Paris Agreement' in 2015. Furthermore, 'carbon neutrality' is being legislated.

In addition, technologies related to greenhouse gas collection and storage are being developed to reduce greenhouse gases, which are the cause of global warming. In particular, various technologies are being researched and developed to reduce carbon dioxide emissions, a representative greenhouse gas. There are energy saving technology to reduce the emission of carbon dioxide, technology to separate and recover carbon dioxide from exhaust gas, technology to use or fix carbon dioxide, and alternative energy technology that does not emit carbon dioxide.

At this time, as a technology for separating and recovering carbon dioxide, an absorption method, an adsorption method, a membrane separation method, and a deep cooling method are being researched and developed. In particular, in the absorption method, a process using ethanolamine is used, and ethanolamine is used in a process of removing CO2 and H2S gas from natural gas or gas from an oil refinery or removing CO2 from ammonia such as a fertilizer plant. Ethanolamine has the property of absorbing acidic gas and releasing it again when heated.

Here, ethanolamine is generally used because monoethanolamine (MEA), a primary amine, has high basicity and low equivalent weight, and diethanolamine (DEA), a secondary amine, and triethanolamine, a tertiary amine Amine (triethanolamine, TEA), N-methyl diethanolamine (MDEA), and triisopropanolamine (TIPA) are also used. At this time, when monoethanolamine or diethanolamine is used as an absorbent, the reaction rate is fast, but a large amount of energy is consumed for carbon dioxide separation, a large amount of absorbent is used, and there is a problem in that the absorbent causes corrosion of the equipment, In the case of using MDEA as an absorbent, it is known that there is a problem in that the absorption rate is low, although the corrosiveness and regeneration heat are low. (Korean Patent Registration No. 10-1350902)

In order to solve this problem, Korean Patent Registration No. 10-1335603 discloses a method for producing a mixed absorbent with excellent absorption ability and fast reaction rate using aqueous ammonia and ethylene oxide, but the risk of explosion There is a problem in that a lot of energy is consumed to remove and recover water not involved in the reaction as an excessive amount of ammonia aqueous solution is added so that ethylene oxide in the reaction does not remain.

Republic of Korea Patent Registration No. 10-1335603 (2013.11.26.) Republic of Korea Patent Registration No. 10-1350902 (2014.01.07.)

The present invention has been made to solve the above problems, and an object of the present invention is to provide a manufacturing process of a carbon dioxide absorbent capable of improving productivity by improving energy efficiency by reducing the energy consumed in manufacturing the carbon dioxide absorbent. .

In addition, another object of the present invention is to provide a carbon dioxide absorbent that can be applied to various processes as the composition of the carbon dioxide absorbent can be adjusted according to the composition of exhaust gas.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention, according to a preferred embodiment of the present invention, the reaction step of reacting by introducing ammonia water and ethylene oxide into the reactor (11) (S10); An ammonia removal step (S20) of removing unreacted ammonia in the reaction step (S10) using an ammonia separation tower (13); A water removal step (S30) of concentrating using an evaporator (14a) and removing water using an evaporation tower (14b); a first carbon dioxide absorbent manufacturing step (S40) utilizing the bottom liquid of the evaporator (14a); and a second carbon dioxide absorbent manufacturing step (S50) of adding other components to the first carbon dioxide absorbent according to the composition of the exhaust gas.

Here, in the reaction step (S10), ammonia gas is introduced into the reactor 11, the ammonia water, the ammonia gas, and the ethylene oxide are reacted at a molar ratio of 1 to 5: 1, so that the unreacted ammonia water It is characterized in that the energy consumed in the recovery process can be reduced.

In addition, in the reaction step (S10), ammonia water and ethylene oxide react in the reactor 11, and a plug flow reactor 12 is additionally provided at the rear of the reactor 11 to secure the residence time required for the reaction It is characterized in that the ethylene oxide is completely reacted.

Here, the ammonia and water removed from the ammonia removal step (S20) to the water removal step (S30) and the evaporator (14a) are supplied back to the absorber (21a) and the third mixer (21b) to produce ammonia water. to be characterized

In addition, the carbon dioxide absorbent prepared in the first carbon dioxide absorbent manufacturing step (S40) is characterized in that it includes MEA, DEA, TEA, MEG, DEG and TEG.

At this time, in the second carbon dioxide absorbent manufacturing step (S50), the bottom liquid of the evaporator 14a is injected into the first nozzle of the second mixer 20, and water is removed from the bottom liquid of the evaporator 14a. MEA produced through the bottom liquid of the dehydration tower 15 through the MEA distillation tower 16, DEA produced through the bottom liquid of the MEA distillation tower 16 through the DEA distillation tower 17, and the DEA distillation tower 17 After the bottom liquid has passed through the EG removal tower 18, the TEA distillation tower 19, and the generated TEA and newly supplied water are injected into the second nozzle by adjusting the component ratio according to the composition of the flue gas, and the input from the first nozzle It is characterized in that the second carbon dioxide absorbent is continuously produced by mixing the liquid and the liquid injected from the second nozzle.

As described above, the carbon dioxide absorbent according to the present invention eliminates the risk of explosion of ethylene oxide by adding gaseous ammonia, thereby saving energy consumption compared to the method of adding an excessive amount of aqueous ammonia. make it an advantage

In addition, the carbon dioxide absorbent manufacturing process according to the present invention has an advantage of providing a carbon dioxide absorbent according to the composition of exhaust gas.

1 is a flowchart of a process for manufacturing a carbon dioxide absorbent according to a preferred embodiment of the present invention.
2 is a schematic diagram schematically showing a process for manufacturing a carbon dioxide absorbent according to a preferred embodiment of the present invention.
3 is a schematic view of a process for measuring carbon dioxide absorbing performance of a carbon dioxide absorbent according to a preferred embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

With reference to the accompanying drawings below, specific details for the practice of the present invention will be described in detail. Like reference numbers refer to like elements, regardless of drawing, and "and/or" includes each and every combination of one or more of the recited items.

Terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements other than the recited elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The present invention is basically an alkanolamine-based carbon dioxide absorbent that separates and captures carbon dioxide contained in exhaust gas generated after combustion.

Specifically, the carbon dioxide absorbent according to the present invention is made of ethanolamine, and ethanolamine contains both an amine group and a hydroxyl group and is used in carbon dioxide capture technology. At this time, ethanolamine can be prepared using ammonia and ethylene oxide.

The carbon dioxide absorbent according to the present invention is manufactured by the ethanolamine process, and MEA (Mono-Ethanol-Amine) is formed by reacting ammonia ('NH3') dissolved in water with ethylene oxide (Ethylene Oxide, C2H4O, 'EO'). , DEA (Di-Ethanol-Amine), and TEA (Tri-Ethanol-Amine) are produced.

1 is a flowchart of a manufacturing method of a carbon dioxide absorbent according to a preferred embodiment of the present invention, and FIG. 2 is a schematic diagram of a manufacturing process of a carbon dioxide absorbent according to a preferred embodiment of the present invention.

Referring to FIG. 1, the manufacturing method of the carbon dioxide absorbent includes a reaction step (S10), ammonia removal step (S20), water removal step (S30), a first carbon dioxide absorbent manufacturing step (S40), and a second carbon dioxide absorbent manufacturing step (S50). ).

First, the reaction step (S10) is a step of reacting ammonia and ethylene oxide, and reacts by introducing ammonia water and ethylene oxide into the reactor 11.

Here, ethylene oxide is highly reactive and reacts well even at low temperatures, and as an explosive material, there is a risk of explosion when handling it when the remaining material remains after reacting with ammonia.

Conventionally, in order to solve this problem, the risk of explosion was removed by adding an excess amount of ammonia water to completely react so that ethylene oxide does not remain. However, when adding an excessive amount of ammonia water to react with ethylene oxide, there is a problem in that unnecessary excess heat energy is used as the water used to produce the ammonia water does not react and is circulated in the process.

In the reaction step (S10) of the present invention, ammonia water and ethylene oxide are introduced into the reactor 11 to react, and at this time, gaseous ammonia is additionally introduced into the first mixer 10 to completely react the ethylene oxide.

Specifically, in the reaction step (S10), ammonia gas is injected into the first mixer 10 into which ammonia water and ethylene oxide are introduced, so that the ammonia water, the ammonia gas, and the ethylene oxide have a molar ratio of 1 to 5: 1 react with

At this time, when the ammonia water, the ammonia gas, and the ethylene oxide are added in an amount greater than the molar ratio of 1 to 5: 1, energy is excessively consumed as the water used for producing ammonia water is circulated in the process, and 1 to 5 : When added in an amount less than the molar ratio of 1, there is a problem in that there is a risk of explosion due to unreacted ethylene oxide.

More specifically, in the reaction step (S10), ammonia water and ethylene oxide are added to the reactor 11, and an excessive amount of ammonia is added to completely react ethylene oxide, but the insufficient ammonia content is directly injected into gaseous ammonia. Minimize the amount of ammonia water input. Accordingly, the amount of water that is used to produce ammonia water but is circulated without reaction and uses excess thermal energy is minimized to reduce energy consumed in the subsequent process of the evaporator (14a), evaporation tower (14b) and dehydration tower (15). can

According to a preferred embodiment, it is appropriate to react the ammonia water, the ammonia gas, and the ethylene oxide at a molar ratio of 3: 1, and at this time, energy is reduced by 50 to 60% compared to reacting by introducing an excess of ammonia water This can have the effect of reducing cost.

On the other hand, in the reaction step (S10), the reactor 11 into which the ammonia water, the ammonia gas, and the ethylene oxide are introduced is a continuous stirred tank reactor (CSTR).

In addition, in the reaction step (S10), it is preferable to provide a plug flow reactor 12 at the rear end of the reactor 11 to completely react ethylene oxide in order to eliminate the risk of explosion of unreacted ethylene oxide remaining .

The plug flow reactor 12 has a structure in which pipes are twisted to form a long structure, so that a reaction between ammonia and ethylene oxide occurs in the flow phase in the plug flow reactor and can be completely reacted by increasing the residence time.

That is, in the reaction step (S10), ammonia water and ethylene oxide are primarily reacted in the reactor 11, and the residence time required for the reaction is secured in the plug flow reactor 12 provided at the rear of the reactor 11 It reacts secondarily to induce a complete reaction of the ethylene oxide, thereby minimizing the risk due to residual ethylene oxide during distillation.

That is, in the reaction step (S10), an excessive amount of ammonia compared to ethylene oxide is added, but by additionally introducing ammonia in the form of gas, the amount of water circulated without reacting is minimized to reduce energy, and a plug flow at the rear end of the continuous stirred tank reactor A reactor was additionally provided to secure the residence time necessary for the reaction so that highly reactive ethylene oxide completely reacted so that ethylene oxide did not remain in the subsequent process.

In the reaction step (S10), ethylene oxide and ammonia water react through the reactor 11, and ethylene oxide remaining unreacted on the flow of the plug flow reactor 12 is completely reacted and transferred to the ammonia separation tower 13.

Next, in the ammonia removal step (S20), unreacted ammonia in the reaction step (S10) is removed using the ammonia separation tower (13).

At this time, the ammonia separation tower 13 is preferably operated under a pressure of 3.2 to 3.5 kg / cmg at a bottom of 140 to 150 ° C and a top of 70 to 90 ° C to separate unreacted ammonia, and the ammonia separation tower ( The bottom liquid from which ammonia and a small amount of water are removed in 13) is transferred to the evaporator 14a.

Next, in the water removal step (S30), the bottom liquid from which ammonia is removed in the ammonia removal step (S20) is concentrated using an evaporator (14a), and water is removed using an evaporation tower (14b).

Here, the evaporator 14a is a gas-liquid separator, and evaporates a small amount of ammonia and a large amount of water using a reboiler.

The evaporator 14a is formed in a flash drum structure, and the liquid under pressure is heated to cause a rapid volume expansion in the container, so that the pressure is reduced and the volatile components are easily vaporized and collected at the top to release the volatile components One liquid is collected at the bottom of the container, and volatile components can be easily separated by evaporation.

In the water removal step (S30) according to the present invention, as the evaporator 14a is formed in a flash drum structure and a lot of droplets of MEA, DEA and TEA are generated, an evaporation tower 14b is additionally provided it is desirable

That is, the evaporation tower 14b is a distillation tower for removing water and is disposed after the evaporator 14a to remove water, thereby supplementing the recovery rate of MEA, DEA and TEA.

At this time, the evaporation tower (14b) is operated under the condition of 105 ~ 110 ℃ under the pressure of 0 ~ 0.1kg / cm2g in the tower, and operated under the condition of 130 ~ 140 ℃ under the pressure of 0.1 ~ 0.4kg / cmg in the bottom of the tower to remove water. It is desirable to remove

In addition, in the water removal step (S30), the bottom liquid from which ammonia is removed is concentrated using an evaporator (14a), water is removed using an evaporation tower (14b), and then dehydration tower (15) is used in vacuum. Water is removed in parts per million.

That is, in the water removal step (S30) according to the present invention, water is removed from the bottom liquid of the ammonia separation tower 13, which is the bottom liquid from which ammonia is removed in the ammonia removal step (S20), and the evaporator (14a) The concentration of MEA, DEA, and TEA is increased and concentrated by removing water using the evaporation tower (14b), and the recovery rate of MEA, DEA, and TEA can be supplemented using the evaporation tower (14b). It is preferred to remove water in parts per million.

On the other hand, in the carbon dioxide absorbent manufacturing process according to the present invention, the water removed through the water removal step (S30) is reused for preparing ammonia water.

Here, the water removed in the water removal step (S30) contains ammonia, which is a toxic substance, and is reused for producing ammonia water without discharging it to the outside, so that ammonia water can be effectively produced and has advantages in terms of environment.

Referring to FIG. 1, in the water removal step (S30), ammonia and water are removed by the evaporator 14a to concentrate MEA, DEA, and TEA. 3 It is preferable to re-supply to the mixer 21b to make ammonia water and reuse it.

In addition, the removed ammonia and water are re-supplied to the absorber 21a and the third mixer 21b to produce ammonia water, and the prepared ammonia water is introduced into the first mixer 10.

As shown in FIG. 1, in the water removal step (S30), water is removed from the evaporator 14a, the evaporation tower 14b, and the dehydration tower 15, and the removed water is passed through the absorber 21a and the third mixer. It is transported to (21b) and mixed with additionally added ammonia to produce ammonia water and reused. In addition, the ammonia purified on the top of the ammonia separation tower 13 is transferred to the absorber 21a and the third mixer 21b and can be used for preparing ammonia water.

Here, the absorber 21a is preferably a tubular heat exchange type absorber for producing ammonia water, and the third mixer 21b is ammonia and water removed from the ammonia distillation column and water removed from the evaporator 14a. Ammonia water is prepared by mixing.

In addition, the present invention is formed in a circulation structure capable of recovering and reusing ammonia and water, and supplies the ammonia water produced through the third mixer 21b to the circulation tank 22, and to the circulation tank 22 The supplied ammonia water is used again to manufacture the carbon dioxide absorbent. Specifically, the ammonia water supplied to the circulation tank 22 is transferred to the first mixer 10, mixed, and then transferred to the reactor 11 to form a circulation structure in the carbon dioxide absorbent manufacturing process according to the present invention. .

That is, in the carbon dioxide absorbent manufacturing process according to the present invention, referring to FIG. 1, the ammonia and water removed from the ammonia removal step (S20) to the water removal step (S30) are absorbed by an absorber 21a and a third mixer 21b. ) and forms a general circulation structure in which it is re-supplied to produce 30 ~ 35 wt% ammonia water.

That is, the ammonia and water removed from the ammonia removal step (S20) to the water removal step (S30) and the evaporator 14a are supplied back to the first mixer 10 to produce ammonia water.

Next, in the first carbon dioxide absorbent preparation step (S40), the bottom liquid of the evaporator 14a is utilized, and the carbon dioxide absorbent prepared according to the manufacturing process of the present invention is a mixture of MEA, DEA, TEA, MEG, DEG, and TEG. is an absorbent.

Referring to FIG. 1, in the carbon dioxide absorbent manufacturing step (S40), the bottom liquid of the evaporator 14a is injected into the first nozzle of the second mixer 20, and the second mixer 20 The carbon dioxide absorbent may be continuously prepared at a constant concentration by mixing MEA, DEA, TEA, and water in a nozzle.

First, the bottom liquid of the dehydration column 15 from which water is removed in the water removal step (S30) is transferred to the MEA distillation column 16 and the DEA distillation column 17, and high-purity MEA is formed on the top of the MEA distillation column 16 produced, and high-purity DEA is produced on the top of the DEA distillation tower (17).

Specifically, DEA is produced on the top of the DEA distillation column 17, and at the bottom of the DEA distillation column 17, there is a bottom liquid remaining after the DEA is produced, and TEA having a relatively high boiling point compared to MEA and DEA. It contains more than 75%, and the by-reactants MEG (Mono-Ethylene-Glycol, DEG (Di-Ethylene-Glycol) and TEG (Tri-Ethylene-Glycol) constitute 1%.

In addition, the bottom liquid of the DEA distillation column 17 is transferred to the EG removal column 18 to remove trace amounts of glycols (MEG, DEG, and TEG) and DEA, and is circulated to the DEA distillation column 17 and reused. At this time, the bottom liquid of the EG removal column 18 from which glycols are removed is composed of DEA and TEA.

The bottom liquid of the EG removal tower (18) is transported to a buffer tank and stored in a buffer tank since the TEA distillation tower (19), which is a subsequent process, is a short distillation batch column, and is stored. produce TEA. In addition, the TEA distillation column 19 produces high-purity TEA by separating, transporting, and recovering the distillate composed of DEA and TEA to the DEA distillation column 17.

Next, in the second carbon dioxide absorbent manufacturing step (S50), other components are added to the first carbon dioxide absorbent according to the composition of the exhaust gas.

The carbon dioxide absorbent prepared in the first carbon dioxide absorbent manufacturing step (S40) is a mixed absorbent of MEA, DEA, TEA, MEG, DEG and TEG, and the second carbon dioxide absorbent manufacturing step (S50) is suitable for the composition of the exhaust gas. A second carbon dioxide absorbent is prepared by adding other components to the first carbon dioxide absorbent in which MEA, DEA, TEA, MEG, DEG, and TEG are mixed.

Here, the other component is one selected from the group consisting of MEA, DEA, TEA, water, and a mixture thereof, and the concentration of MEA, DEA, and TEA is adjusted to optimize the exhaust gas composition by adding the other component to the first carbon dioxide absorbent. A second carbon dioxide absorbent is prepared.

Referring to FIG. 1, the second carbon dioxide absorbent manufacturing step (S50) is manufactured in a second mixer 20, and the second mixer 20 is provided with a first nozzle and a second nozzle and flows into the second mixer. You can control the amount of

In the second carbon dioxide absorbent manufacturing step (S50), the carbon dioxide absorbent specialized for the composition of the exhaust gas may be manufactured by adjusting the first nozzle and the second nozzle of the second mixer 20.

In addition, the second carbon dioxide absorbent manufacturing step (S50) continuously manufactures a process of diluting the carbon dioxide absorbent prepared at a certain concentration to a desired concentration by newly supplying MEA, DEA, TEA, and water according to the composition of the exhaust gas. can do.

At this time, it is preferable that the first nozzle is formed as a motive nozzle and the second nozzle is formed as a suction nozzle.

Specifically, in the second carbon dioxide absorbent manufacturing step (S50), the bottom liquid of the evaporator 14a is injected into the first nozzle of the second mixer 20, and the component ratio is adjusted according to the composition of the exhaust gas to obtain the carbon dioxide absorbent. 2 The second nozzle of the mixer 20 includes MEA generated by passing the bottom liquid of the evaporation column 15 from which water is removed from the bottom liquid of the evaporator 14a through the MEA distillation column 16, and the MEA distillation column ( DEA produced from the bottom liquid of 16) passed through the DEA distillation column 17, and TEA produced through the TEA distillation column 19 after the bottom liquid of the DEA distillation column 17 passed through the EG removal column 18 and newly supplied put in the water A carbon dioxide absorbent according to the composition of the exhaust gas can be continuously produced in one process by adjusting the mixed component ratio of the bottom liquid of the evaporator introduced from the first nozzle and the bottom liquid introduced from the second nozzle according to the composition of the exhaust gas.

Conventional carbon dioxide absorbents require additional time and cost because the amine produced in the amine synthesis process is separated in a distillation tower and the desired components are mixed and used, whereas the carbon dioxide absorbent according to the present invention is MEA, DEA, TEA, MEG , DEG, TEG, and water are mixed as a carbon dioxide absorbent in the form of an aqueous solution. The carbon dioxide absorbent in the form of an aqueous solution can be directly applied to capture carbon dioxide, and can be manufactured appropriately for the composition of exhaust gas in a continuous process during the manufacture of the carbon dioxide absorbent. Can save time and cost.

Hereinafter, the configuration and operation of the present invention will be described in more detail through specific preparation examples, examples, comparative examples, and experimental examples of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

Preparation Example 1

Ammonia water, ammonia gas, and ethylene oxide are introduced into the first mixer 10 at a molar ratio of 3:1 to react ethylene oxide, and ammonia and ethylene oxide are reacted through a continuous stirred tank reactor 11 and a plug flow reactor 12 react completely. Thereafter, ammonia remaining after the reaction was removed in the ammonia separation tower 13, and water was removed in the evaporator 14a and the evaporation tower 14b to prepare a first carbon dioxide absorbent in which MEA, DEA, and TEA were mixed. The mixing ratio of the finally produced absorbent is shown in Table 1 below.

Preparation Example 2

It was prepared in the same manner as in Preparation Example 1, but ammonia water, ammonia gas, and ethylene oxide were added to the first mixer 10 at a molar ratio of 7:1 to react ethylene oxide.

Preparation Example 3

It was prepared in the same manner as in Preparation Example 1, but ammonia water, ammonia gas, and ethylene oxide were added to the first mixer 10 at a molar ratio of 9:1 to react ethylene oxide.

division MEA (wt%) DEA (wt%) TEA (wt%) HO (wt%) MEG (wt%) DEGs (wt%) TEG (wt%) Preparation Example 1 30.55 30.37 17.58 21.32 0.1 0.03 0.05 Preparation Example 2 33.96 29.45 15.24 21.20 0.09 0.04 0.02 Preparation Example 3 35.19 29.53 13.65 21.53 0.04 0.02 0.04

As shown in Table 1, it was confirmed that the carbon dioxide absorbent prepared by adding ammonia water, ammonia gas, and ethylene oxide at a molar ratio of 3:1 according to Preparation Example 1 had increased DEA and TEA components.

Example

An aqueous absorbent solution containing 30 wt% of the carbon dioxide absorbent prepared according to Preparation Example 1 was prepared.

comparative example

An aqueous absorbent solution containing 30 wt% of MEA was prepared.

Experimental example

및 흡수제 농도를 조절하였고, 탈거탑(12)에서 이산화탄소가 탈거되어 재생된 흡수제 흐름의

및 흡수제 농도는 흡수제 보충 흐름(17)을 조절함으로써 2개의 흡수제 흐름(8, 19)이 동일한 값을 가지게 하여 이산화탄소 흡수-탈거 공정의 연속을 운전을 모사하였다. Absorption tower (2) feed absorbent stream (8) by adjusting the flow rate of the absorbent feed stream (5) and the carbon dioxide concentration and flow rate of the water feed stream (4) according to Examples and Comparative Examples to confirm the carbon dioxide absorption-separation performance of

And the absorbent concentration was adjusted, and the carbon dioxide was stripped in the stripping column 12 and the regenerated absorbent flow

and the absorbent concentration by adjusting the absorbent make-up stream 17 so that the two absorbent streams 8 and 19 have the same value to simulate the continuous operation of the carbon dioxide absorption-removal process.

The carbon dioxide absorption-removal process was performed using AspenPlus V11 as a process simulator with respect to the process configuration shown in FIG. 3 . As shown in FIG. 3, the flue gas 1 is supplied to the lower part of the absorption tower 2 and flows upward, and the absorbent 8 is supplied to the upper part of the absorption tower 2 and the inside of the absorption tower 2 It flows downward, wetting the surface of the filling. Inside the absorption tower (2), while wetting the packing, the absorbent (8) flowing downward and the flue gas (1) flowing upward are gas-liquid contact, mass transfer, ionization and acid-flow in a counter-current flow environment. After carbon dioxide is absorbed and separated by a base reaction, the treated gas 3 is discharged to the atmosphere.

The CO2 removal efficiency is the ratio of the CO2 mole absorbed and separated by the absorbent (8) to the CO2 mole contained in the combustion exhaust gas (1), using the process simulation results for the combustion exhaust gas (1) and the processed gas (3). It was calculated as in Equation 1 below.

In addition, in order to indicate the extent to which the absorbent liquid streams 8, 9, 11, 13, 14, 16, and 19 absorbed carbon dioxide, calculation is performed as shown in Equation 2 using the process simulation results for each absorbent liquid stream. One CO2 loading (α) was used.

In the continuous carbon dioxide absorption-separation process, the absorbent reacted with carbon dioxide in the absorption tower 2 is supplied to the stripping tower 12, carbon dioxide is stripped by distillation to remove it from the absorbent, and then supplied to the absorption tower 2 to carbon dioxide By being reused for absorption, it constitutes a continuous process of absorption and removal of carbon dioxide.

로 나타내고 탈거탑(12)에서 흡수탑(2)으로 공급되는 흡수제 액체 흐름(13, 14, 16, 19)의 CO₂loading은

로 나타내었다.The absorbent liquid streams 9 and 11 supplied to the stripping tower 12 from the bottom of the absorption tower 2 are the absorbent liquid streams 13, 14 and 16 supplied to the absorption tower 2 after carbon dioxide is removed in the stripping tower 12 , 19), CO₂loading (α) is relatively high, so it becomes a CO₂rich absorbent, and the CO₂loading at this time is

The CO2 loading of the absorbent liquid streams 13, 14, 16, and 19 supplied from the stripping tower 12 to the absorption tower 2 is

indicated by

= 0이며 흡수제에 의한 이산화탄소의 흡수-분리가 진행될수록 흡수탑(2)에서 탈거탑(12)로 공급되는 흡수제 액체 흐름의 CO₂loading,

는 증가하게 된다. At the beginning of the operation of the continuous carbon dioxide absorption-removal process, CO2loading of the absorbent prior to reacting with carbon dioxide is

= 0, and as the absorption-separation of carbon dioxide by the absorbent progresses, the CO₂loading of the absorbent liquid flow supplied from the absorption tower (2) to the stripping tower (12),

will increase

The CO₂rich absorbent supplied to the stripping tower 12 evaporates water and carbon dioxide by the thermal energy supplied to the reboiler 23 at the bottom of the stripping tower and moves to the upper part of the stripping tower 12. In this process, the internal The surface of the packing and the empty space form a gas-liquid phase equilibrium of the absorbent and carbon dioxide, and the resulting concentration gradient provides a driving force for moving water and carbon dioxide to the upper part of the stripping tower 12. Vapor water and carbon dioxide moved to the top of the stripping column 12 are supplied to the condenser 22, and most of the water condensed by the cooling water is returned to the stripping column 12, and some of it is at the level of maintaining the absorbent concentration. High-concentration carbon dioxide that is discharged as wastewater (21) and is not condensed is separated into a separate stream (20), and carbon dioxide stripping is completed.

은 감소하게 되지만 흡수제-물-이산화탄소의 상평형에 조건에 의해

은

보다는 작아질 수 있으나 0이 될 수는 없다.The evaporation of water and carbon dioxide in the stripping tower (12) reboiler (23) increases CO2 loading of the absorbent,

is reduced, but by the condition of the phase equilibrium of absorbent-water-carbon dioxide

silver

can be less than, but cannot be zero.

인 흡수제 액체 흐름(9)은 Lean-rich absorbent heat exchanger(10)에서 이산화탄소가 탈거되어 온도가 높고 CO₂loading이 낮아 인 흡수제 액체 흐름(13)의 고온으로부터 열교환에 의해

인 흡수제 액체 흐름(11)으로 가열된 다음 탈거탑(12)에 공급됨으로써 리보일러(23) 가열에 필요한 에너지 공급량을 최소화할 수 있다.

흡수제 액체 흐름(13)은 Lean-rich absorbent heat exchanger(10)에서

흡수제 액체 흐름(14)으로 열교환된 다음

흡수제 Cooer(15)에서 냉각된 후 흡수탑(2)으로 공급된다. 도 3에서는 공정 모사 기법상 2개의

흡수제 흐름(8, 19)으로 나타내었으나, 실제 운전에서는 2개의

흡수제 흐름(8, 19)은 동일한 유체 흐름에 해당하며 공정 모사에 사용된 2개의

흡수제 흐름(8, 19) 냉각기(7, 15)의 설정에 의해 이 조건을 충족하였다. High CO₂loading

The phosphorus absorbent liquid stream (9) has high temperature and low CO2 loading as carbon dioxide is removed from the lean-rich absorbent heat exchanger (10). by heat exchange from the high temperature of the phosphorus absorbent liquid stream 13.

By being heated by the phosphorus absorbent liquid stream 11 and then supplied to the stripping column 12, the amount of energy supplied for heating the reboiler 23 can be minimized.

The absorbent liquid flow (13) is in the lean-rich absorbent heat exchanger (10).

After heat exchange with the absorbent liquid stream (14)

After cooling in the absorbent cooer (15), it is supplied to the absorption tower (2). In Figure 3, two process simulation techniques

It is shown as an absorbent flow (8, 19), but in actual operation, two

Sorbent streams (8, 19) correspond to the same fluid streams and are two

The setting of the absorbent streams (8, 19) coolers (7, 15) met this condition.

및 흡수제 농도를 조절하였고, 탈거탑(22)에서 이산화탄소가 탈거되어 재생된 흡수제 흐름의

및 흡수제 농도는 흡수제 보충 흐름(17)을 조절함으로써 2개의 흡수제 흐름(8, 19)이 동일한 값을 가지게 하여 이산화탄소 흡수-탈거 공정의 연속을 운전을 모사하였다. By adjusting the flow rate of the absorbent feed stream (5) and the carbon dioxide concentration and flow rate of the water feed stream (4), the absorption tower (2) feed absorbent stream (8)

And the absorbent concentration was adjusted, and the carbon dioxide was stripped in the stripping column 22 and the regenerated absorbent flow

and the absorbent concentration by adjusting the absorbent make-up stream 17 so that the two absorbent streams 8 and 19 have the same value to simulate the continuous operation of the carbon dioxide absorption-removal process.

Property method - Electrolyte NRTL Combustion flue gas (1) - Keep constant at 40 ^o C, 0.02 barG, 20,000 Nm ³ /hr Absorption tower (2) - Calculation Type : Rate based
-Number of Stages : 10
-Diameter : 2.5m
-Packed Height : 10m
- Packing Type : Pall Ring 1/2“, Generic Metal carbon dioxide absorption rate - CO ₂ removal efficiency: over 90% Lean-rich Absorbent Heat Exchange(10) - Hot Stream Outlet(14) Temperature : 80 ^o C Absorbent Cooler(7, 15) - Hot Stream Outlet(8, 16) Temperature : 30 ^o C Removal tower (12)

조절을 위해 변화- Calculation Type : Rate based
-Number of Stages: 10
- Feed Stram(11) : Above 5 Stage
-Diameter : 2m
-Packed Height : 10m
- Packing Type : Pall Ring 1/2“, Generic Metal
- Reflux Ratio (mole): 0.5, maintaining 95% of the CO ₂ concentration of the stripping CO ₂ flow (20)
- Bottom to Feed Ratio: of absorbent flow (13, 14, 16, 16)

change to control stripping carbon dioxide (20) - Stripping carbon dioxide concentration: 95vol%

)을 0.2로 설정하여 상기 표 2에 기재된 조건으로 공정 모사를 수행하였으며, 그 결과는 표 3에 나타내었다.CO ₂ loading (

) was set to 0.2 to perform process simulation under the conditions described in Table 2 above, and the results are shown in Table 3.

Example comparative example Absorption tower (2) absorbent feed stream (8) flow rate 100 ton/hr = 98.28 m ³ /hr 77 ton/hr = 78 m ³ /hr Absorbent flow rate with absorbent feed stream (8) 448.52 kmoles-example/hr 428.169 kmoles-MEA/hr Stripping column (12) Condenser (22) heat duty -2.67GJ/hr -26.27GJ/hr Stripping tower(12) Reboiler(23) heat duty 19.61GJ/hr 38.46GJ/hr

According to Table 3, in Example, the operating energy of the condenser 22 when removing carbon dioxide is -2.67 GJ/hr, and the operating energy of the reboiler 23 is 19.61 GJ/hr, and the comparative example includes the same 30 wt% carbon dioxide absorbent. Compared to, it can be seen that 50.98% of the energy required for the stripping tower reboiler is reduced.

That is, the carbon dioxide absorbent prepared according to the manufacturing process of the present invention is a mixed absorbent of MEA, DEA, TEA, MEG, DEG and TEG, and it can be seen that less energy is consumed during operation compared to the comparative example, which is a single MEA absorbent. there is.

In addition, the carbon dioxide absorbent manufacturing process according to the present invention can improve energy efficiency by reducing energy during carbon dioxide removal, thereby reducing the environmental impact generated when producing energy supplied to the production process and improving productivity. can

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

S10: reaction step
S20: ammonia removal step
S30: water removal step
S40: first carbon dioxide absorbent manufacturing step
S50: Second carbon dioxide absorbent manufacturing step
10: first mixer
11: Reactor
12: plug flow reactor
13: ammonia separation tower
14a: evaporator, 14b: evaporation tower
15: dehydration tower
16: MEA distillation column
17: DEA distillation column
18: EG removal tower
19: TEA distillation column
20: second mixer
21a: absorber, 21b: third mixer
22: circulation tank

Claims (6)

A reaction step of reacting ammonia water and ethylene oxide by introducing them into the reactor 11 (S10);
An ammonia removal step (S20) of removing unreacted ammonia in the reaction step (S10) using an ammonia separation tower (13);
A water removal step (S30) of concentrating using an evaporator (14a) and removing water using an evaporation tower (14b);
a first carbon dioxide absorbent manufacturing step (S40) utilizing the bottom liquid of the evaporator (14a); and
A second carbon dioxide absorbent manufacturing step (S50) of adding other components to the first carbon dioxide absorbent according to the composition of the exhaust gas; including,
In the reaction step (S10), ammonia gas is separately injected in an amount of 10 to 20% by weight of ammonia water into the reactor 11, and the ammonia water, the ammonia gas, and the ethylene oxide are 1 to 5: 1 It reacts in a molar ratio, and by introducing ammonia in gas form, the amount of ammonia input in the form of an aqueous solution is minimized to use excess heat energy unreacted in the ammonia water and reduce the energy consumed in the recovery process of circulating water,
The other component is one selected from the group consisting of MEA, DEA, TEA, water and mixtures thereof,
In the second carbon dioxide absorbent manufacturing step (S50),
The bottom liquid of the evaporator (14a) is injected into the first nozzle of the second mixer (20),
The bottom liquid of the dehydration tower 15, from which water is removed from the bottom liquid of the evaporator 14a, passes through the MEA distillation tower 16 to produce MEA, and the bottom liquid of the MEA distillation tower 16 passes through the DEA distillation tower 17. The DEA produced through the distillation column 17, the bottom liquid of the DEA distillation column 17 passes through the EG removal column 18, and then the TEA produced through the TEA distillation column 19 and newly supplied water, by adjusting the component ratio according to the composition of the Into the second nozzle,
According to the composition of the exhaust gas, by adjusting the mixed component ratio of the bottom liquid of the evaporator injected into the first nozzle and the bottom liquid introduced into the second nozzle, a carbon dioxide absorbent having a concentration changed according to the composition of the exhaust gas is continuously produced in one process. and
In the reaction step (S10), ammonia gas is separately injected into the first mixer into which ammonia water and ethylene oxide are added, and ammonia water, ammonia gas, and ethylene oxide react in the reactor,
A process for producing a carbon dioxide absorbent, characterized in that a plug flow reactor is additionally provided at the rear end of the reactor to ensure a residence time required for the reaction to completely react the ethylene oxide. delete delete According to claim 1,
The ammonia and water removed from the ammonia removal step (S20) to the water removal step (S30) and the evaporator (14a) are supplied back to the absorber (21a) and the third mixer (21b) to produce ammonia water. Carbon dioxide absorbent manufacturing process. According to claim 1,
The carbon dioxide absorbent produced in the first carbon dioxide absorbent manufacturing step (S40) comprises MEA, DEA, TEA, MEG, DEG and TEG. delete