JP2871335B2 - Method for removing carbon dioxide in flue gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing CO ₂ (carbon dioxide) contained in flue gas. More specifically, the present invention relates to a method for removing CO ₂ in flue gas at atmospheric pressure using a mixed aqueous solution of a specific amine.

[0002]

2. Description of the Related Art In recent years, the greenhouse effect of CO ₂ has been pointed out as one of the causes of the global warming phenomenon, and countermeasures have been urgently required internationally to protect the global environment. CO ₂
As a source of the occurrence, all human activity fields burning fossil fuels tend to be increasingly demanded for emission control. Along with this, a method and method for contacting boiler flue gas with an alkanolamine aqueous solution and removing and recovering CO ₂ in flue gas for power generation facilities such as thermal power plants that use large amounts of fossil fuels Methods for storing the released CO ₂ without releasing it to the atmosphere are being vigorously studied.

Examples of the alkanolamine include monoethanolamine, diethanolamine, triethanolamine, methyldiethanolamine, diisopropanolamine, and diglycolamine.
Usually, monoethanolamine (abbreviated as MEA) is preferably used.

However, even if the above-mentioned alkanolamine aqueous solution represented by MEA is used as an absorbing solution for absorbing and removing CO _{2 in} combustion exhaust gas, the absorption of CO ₂ per a predetermined amount of the aqueous amine solution having a predetermined concentration can be achieved. The amount of CO ₂ absorbed per unit amine mole of the aqueous amine solution of the predetermined concentration, the absorption rate of CO _{2 at} the predetermined concentration, and the heat energy required for regeneration of the aqueous alkanolamine solution after absorption, which is not always satisfactory. is not.

There are many known techniques for separating an acidic gas from various mixed gases using an amine compound. JP-A-53-100180 discloses that (1) at least one secondary amino group or tertiary carbon atom which is part of a ring and bonded to either a secondary carbon atom or a tertiary carbon atom. An amine mixture consisting of at least 50 mol% of a sterically hindered amine containing a primary amino group bound to a tertiary amino alcohol and at least about 10 mol%, and (2) said amine mixture which is a physical absorbent for acidic gases A method for removing acidic gases comprising contacting a gaseous mixture with an amine-solvent liquid absorbent comprising a solvent for use is described. Sterically hindered amines include 2-piperidineethanol [2- (2-hydroxyethyl group) -piperidine] and 3-amino-3-methyl-
1-butanol or the like is used as a tertiary amino alcohol;
-Dimethylamino-1-propanol, etc .; a solvent, a sulfoxide compound which may contain up to 25% by weight of water; etc .; Hydrogen sulfide, eg 3
Normally gaseous mixture with 5% CO ₂ and 10-12% of H ₂ S "is illustrated, also in the embodiment CO ₂ itself is used.

Japanese Patent Application Laid-Open No. 61-71819 discloses a composition for scraping an acidic gas containing a non-aqueous solvent such as a sterically hindered amine and sulfolane. Examples of the sterically hindered primary monoamino alcohol include 2-amino-2-methyl-1-propanol (abbreviated as AMP) and the like,
Also used. In the embodiment, CO ₂ and nitrogen, and CO ₂ and helium are used as the gas to be treated. Further, an aqueous solution of an amine and potassium carbonate or the like is also used as the absorbent. It also describes the use of water. Further, the publication describes the advantage of the sterically hindered amine with respect to the absorption of CO ₂ using a reaction formula.

Chemical Engineering Science (C)
chemical Engineering Science), Vol. 41, No. 4, 99
Pages 7 to 1003 disclose the carbon dioxide absorption behavior of an aqueous AMP solution that is a hindered amine. As the gas to be absorbed, atmospheric pressure CO ₂ and a mixture of CO ₂ and nitrogen are used.

Chemical Engineering Science (C)
chemical Engineering Science), Vol. 41, No. 2, 40
On pages 5 to 408, the absorption rates of hindered amines such as AMP and linear amines such as MEA for CO ₂ and H ₂ S are reported at around normal temperature. According to this, when the partial pressure of CO ₂ is 1 atm, there is no significant difference between the two at an aqueous solution concentration of 0.1 to 0.3M. But,
Using an aqueous solution having a concentration of 0.1 M, the partial pressure of CO ₂ was adjusted to 1.0.
5. If the pressure is reduced to 0.05 atm,
MP has a much lower absorption rate than MEA.

US Pat. No. 3,622,267 uses an aqueous mixture containing methyldiethanolamine and monoethylmonoethanolamine and uses a high partial pressure of CO ₂ contained in a synthesis gas such as a partially oxidized gas such as crude oil. 40
A technique for purifying synthesis gas containing 30% CO _{2 at} atmospheric pressure is disclosed.

[0010] German Patent Publication No. 1,542,415 discloses a technique of adding a monoalkylalkanolamine or the like to a physical or chemical absorbent in order to improve the absorption rate of CO ₂ , H ₂ S and COS. Similarly, German Offenlegungsschrift 1,904,428 discloses a technique in which monomethylethanolamine is added for the purpose of improving the absorption rate of methyldiethanolamine.

US Pat. No. 4,336,233 discloses that a 0.81-1.3 mol / l aqueous solution of piperazine is used as a washing liquid for refining natural gas, synthesis gas and gasified coal gas, and that piperazine is methyldiethanolamine. There is disclosed a technique used as a washing solution in an aqueous solution together with a solvent such as triethanolamine, diethanolamine, and monomethylethanolamine.

Similarly, Japanese Patent Application Laid-Open No. Sho 52-63171 discloses a CO containing a tertiary alkanolamine, a monoalkylalkanolamine or the like, and a piperazine derivative such as piperazine or hydroxyethylpiperazine added as an accelerator.
_Two absorbents are disclosed.

[0013]

As described above, there is a need for a method for efficiently removing CO ₂ from combustion exhaust gas.
In particular, when treating flue gas with an aqueous solution containing a certain concentration of CO ₂ absorbent, an absorbent having a large CO ₂ absorption amount per unit mol of the absorbent, a large amount of CO ₂ absorbed per unit volume of the aqueous solution, and an absorption rate. The choice is a major challenge for the time being. Furthermore after absorption of CO _2, separating the CO _2,
An absorbent that requires less heat energy when regenerating the absorbent is desired. In particular, it is desired to improve the absorption rate of an absorbent having a small absorption rate despite its high CO ₂ absorption capacity.

[0014]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies on an absorbent used for removing CO _{2 in} combustion exhaust gas, and as a result, a specific amine compound (X1 ) , (X2), (X3) or (X4)
Relatively small amounts of specific amine compounds (Y1 ), (Y
The use of a mixture of (2), (Y3) or (Y4) can result in specific amine compounds (X1 ), (X2), (X3) and the like.
The present invention has been found to be particularly effective in improving the absorption rate of (X4 ), thereby completing the present invention.

That is, the present invention relates to (1) (A)
It has one rucholic hydroxyl group and a primary amino group,
Primary amino groups are tertiary having two unsubstituted alkyl groups
A compound bonded to a carbon atom, and (C) a die
Amine compound selected from the group consisting of tanolamine
(X1) 100 parts by weight, (D) piperazine, (E)
Peridine, (F) morpholine, (G) glycine,
(H) 2-piperidinoethanol, and (I) in the molecule
Having one alcoholic hydroxyl group and a secondary amino group;
Secondary amino groups are those having 2 or more carbon atoms, including the bonding carbon atom.
N atom bonded to a group having a chain and unsubstituted with 3 or less carbon atoms
From the group consisting of compounds having an alkyl group
Mixed water of 1 to 25 parts by weight of selected amine compound (Y1)
The feature is to contact the solution with the flue gas under atmospheric pressure
A method for removing carbon dioxide in combustion exhaust gas,
(2) (B) one alcoholic hydroxyl group in the molecule
A tertiary amino group having at least three amino groups;
And two or more groups each have a carbon atom including its bonding carbon atom.
Having a chain of several or more and further bonding to the tertiary amino group
Two of those groups are compounds that are unsubstituted alkyl groups.
100 parts by weight of an amine compound (X2) selected from the group
And (D) piperazine, (E) piperidine, (F) mol
Folin, (G) glycine, and (H) 2-piperidino
Amine compounds (Y2) 1 to 1 selected from the group of ethanol
Contacting 25 parts by weight of the mixed aqueous solution with flue gas at atmospheric pressure
The carbon dioxide in the flue gas,
(3) 2-amino-2-methyl-1,3
-Propanediol, 2-amino-2-methyl-1-prop
Lopanol, 2-amino-2-ethyl-1,3-propa
Diol and 2-amino-2-hydroxymethyl-
Amine compound selected from the group of 1,3-propanediol
(X3), 100 parts by weight of piperazine, piperidine,
Morpholine, glycine, 2-methylaminoethanol
2-piperidinoethanol and 2-ethylaminoethyl
Amine compounds (Y3) 1-2 selected from the group of tanols
Contacting 5 parts by weight of mixed aqueous solution with flue gas under atmospheric pressure
Carbon dioxide in flue gas
(4) t-butyldiethanolamine
100 parts by weight of an amine compound (X4) consisting of
Gin, piperidine, morpholine, glycine and 2-pi
Amination compound selected from the group consisting of piperidino ethanol (Y
4) 1 to 25 parts by weight of the mixed aqueous solution and the exhaust gas under atmospheric pressure
Diacid in combustion exhaust gas characterized by contact with
This is a method for removing carbonized carbon.

[0016]

The specific amine compound (X ) used in the present invention
1), (X2), (X3) or (X4) (hereinafter, this
(The four are collectively referred to as (X)), (Y1), (Y2),
(Y3) or (Y4) (hereinafter, these four types are combined
(Referred to as (Y)) is as described above,
Each of the amine compounds (X) and (Y) may be used in combination with a single compound, or two or more of each may be used in combination.

The amine compound (X1) used in the present invention is
Min compounds (A) and (C), of which
(A) is an alcoholic hydroxyl group and a 1 and a primary amino group, said primary amino group is a compound that binds to a tertiary carbon atom having two unsubstituted alkyl groups, the (A )
In the above, the unsubstituted alkyl groups may be the same or different and each is exemplified by a methyl group, an ethyl group or a propyl group, and both are preferably a methyl group. Compounds belonging to this (A) include 2-amino-2-methyl-1-propanol, 3
-Amino-3-methyl-2-pentanol, 2,3-dimethyl-3-amino-1-butanol, 2-amino-2
-Ethyl-1-butanol, 2-amino-2-methyl-
3-pentanol, 2-amino-2-methyl-1-butanol, 3-amino-3-methyl-1-butanol, 3
-Amino-3-methyl-2-butanol, 2-amino-
2,3-dimethyl-3-butanol, 2-amino-2,
Examples thereof include 3-dimethyl-1-butanol, 2-amino-2-methyl-1-pentanol and the like, and preferred is 2-amino-2-methyl-1-propanol (AMP). (C) which is another amine compound (X1) is a diethanol
Ureamine.

The amine compound (X2) used in the present invention
The amine compound (B) has one alcoholic hydroxyl group and a tertiary amino group, and at least two or more groups bonded to the tertiary amino group have 2 carbon atoms including the bonding carbon atom. In the compound having the above-mentioned chain and two of the groups bonded to the tertiary amino group are unsubstituted alkyl groups, the two unsubstituted alkyl groups may be the same or different from each other, and Group, ethyl group, propyl group, isopropyl group and the like. Such compounds, 2 - di Mechiruami Noe pentanol, 2 - di et <br/> Chiruami Noe pentanol, 2 - d Chirumechiruami Noe Tano <br/> Lumpur, 1 - di Mechiruami Noe pentanol, 1 - di Echirua <br/> Mi Noe pentanol, 1 - d Chirumechiruami Noe pentanol,
2 - di-isopropyl amine Noe pentanol, 1 - di Echirua <br/> Mi Bruno - 2-propanol, 3 - di ethylamine Bruno - 1-propanol or the like can be exemplified, among others 2 - diethylcarbamoyl <br/> Ruami Noe ethanol [DEAE abbreviated] is preferred. Book
The amine compound (X3) used in the present invention is 2-amino-2-
Methyl-1,3-propanediol, 2-amino-2-
Methyl-1-propanol, 2-amino-2-ethyl-
1,3-propanediol and 2-amino-2-hydro
Selected from the group of xymethyl-1,3-propanediol
Amine compound. In addition, the amination used in the present invention
Compound (X4) is t-butyldiethanolamine.

Combination with the amine compound (X1) in the present invention
The amine compound (Y1) used is (D) piperazine
(E) piperidine, (F) morpholine, (G)
Lysine, and (H) 2-piperidinoethanol and amino
Compound (I). Among them, (I) has one alcoholic hydroxyl group and a secondary amino group, and the secondary amino group has an N atom and a carbon atom bonded to a group having a chain of 2 or more carbon atoms including a bonding carbon atom. An amine compound having an unsubstituted alkyl group having the number of 3 or less , and the amine compound (I)
In the above, the chain having 2 or more carbon atoms including the bonding carbon atom is, for example, usually a hydroxyl-substituted alkyl group having 2 to 5 carbon atoms, preferably a hydroxyl-substituted alkyl group having 2 to 3 carbon atoms. The compounds belonging to this (I), 2 - an ethyl <br/> Ami Noe pentanol, 2 - main Chiruami Noe pentanol, 2 -
Flop Ropiruami Noe pentanol, 2 - b Sopuropiruami Noe <br/> pentanol, 1 - d Chiruami Noe pentanol, 1 - main Chirua <br/> Mi Noe pentanol, 1 - flop Ropiruami Noe pentanol, 1 -
Can be exemplified b Sopuropiruami Noe pentanol, etc., among them 2 - d Chiruami Noe pentanol, 2 - is preferably used main Chirua <br/> Mi Noe methanol [MAE abbreviated]. In the present invention, a combination with the amine compound (X2) or (X4)
Amine compound (Y2) or (Y4) used in combination
Is (D) of the amine compound (Y1),
They are the same as (E), (F), (G) and (H).
In the present invention, the compound is used in combination with the amine compound (X3).
Amine compound (Y3) is the same as amine compound (Y1)
(D), (E), (F), (G), (H),
2-methylaminoethanol contained in (I) and 2-methylaminoethanol
Ethylaminoethanol.

The mixing ratio of the amine compound (X) and (Y), when the amine compound (X) is composed of (A) or other (B), per 100 parts by weight of (X), an amine compound (Y )
Is in the range of 1 to 25 parts by weight, more preferably 1 to 10% by weight. When (X) is (C) diethanolamine, the amine compound (Y) is in a range of 1 to 25% by weight, more preferably 1 to 25% by weight, based on 100 parts by weight of (X).
It is in the range of 0 to 25% by weight. The concentration of the amine compound (X) in the mixed aqueous solution (also referred to as an absorbing solution) is usually 15 to 65% by weight, though it depends on the type of (X). The temperature of the mixed aqueous solution at the time of contact with the combustion exhaust gas is usually in the range of 30 to 70 ° C.

The mixed aqueous solution used in the present invention may optionally contain a corrosion inhibitor, an amine compound deterioration inhibitor, and the like.

The term "atmospheric pressure" in the present invention includes a pressure range near atmospheric pressure at which a blower or the like acts to supply combustion exhaust gas.

The process that can be employed in the method of the present invention for removing CO ₂ from flue gas is not particularly limited, but one example thereof will be described with reference to FIG. In FIG. 1, only the main equipment is shown, and the auxiliary equipment is omitted.

In FIG. 1, reference numeral 1 denotes CO 2 removal_TwoTower, 2 at the bottom
Filling unit, 3 is the above filling unit or tray, 4 is CO 2 removal_TwoTower
Combustion exhaust gas supply port, 5 de-CO_TwoFlue gas outlet, 6
Is an absorption liquid supply port, 7 is a nozzle, and 8 is provided as necessary.
9 is a nozzle, 10 is a filling part, 1
1 is a humidification cooling water circulation pump, 12 is a makeup water supply line,
13 is CO_TwoPump for absorbing liquid absorbed
Exchanger 15 is an absorbent regeneration (hereinafter also abbreviated as "regeneration")
Tower, 16 is a nozzle, 17 is a lower filling section, 18 is regeneration heating
Vessel (reboiler), 19 is the upper filling part, 20 is the reflux water port
Pump, 21 is CO _TwoSeparator, 22 is recovered CO_TwoDischarge line
, 23 is a regenerator cooling condenser, 24 is a nozzle, and 25 is a regenerator.
Live tower reflux water supply line, 26 is a combustion exhaust gas supply blower,
27 is a cooler, and 28 is a regeneration tower reflux water supply port.

In FIG. 1, the flue gas is pushed into the flue gas cooler 8 by the flue gas supply blower 26 and comes into contact with the humidified cooling water from the nozzle 9 at the filling section 10.
Is fogging, is directed through a de-CO ₂ tower combustion exhaust gas feed port 4 to the de-CO ₂ column 1. The humidified cooling water in contact with the combustion exhaust gas accumulates in the lower part of the combustion exhaust gas cooler 8 and is circulated to the nozzle 9 by the pump 11. Since the humidified cooling water is gradually lost by humidifying and cooling the combustion exhaust gas, it is replenished through the makeup water supply line 12. To further cool the combustion exhaust gas from the humidified cooling state, a heat exchanger is placed between the humidified cooling water circulation pump 11 and the nozzle 9 to cool the humidified cooling water and supply it to the combustion exhaust gas cooler 8. It becomes possible.

The combustion exhaust gas pushed into the CO ₂ removal tower 1 is supplied with a certain concentration of an absorbing solution supplied from a nozzle 7 and a filling section 2.
In brought into contact countercurrently, CO ₂ in the combustion exhaust gas is absorbed and removed by the absorbing solution, removing CO ₂ combustion exhaust gas upper filling portion 3
Go to. Absorbing liquid supplied to de-CO ₂ tower 1 absorbs CO _2, because of the heat of reaction due to the absorption becomes a temperature higher than the temperature in the normal supply port 6, the heat exchanger by absorbing solution discharge pump 13 that has absorbed CO ₂ It is sent to the vessel 14, heated and led to the absorbent regeneration tower 5. The temperature of the regenerated absorbent is controlled by the heat exchanger 14 or the heat exchanger 1 as necessary.
The cooling can be performed by a cooler 27 provided between the cooling liquid supply port 4 and the absorbing liquid supply port 6.

In the regeneration tower 15, the heating by the regeneration heater 18 is performed.
The absorption liquid is regenerated in the lower filling section 17 by heat, and the heat exchanger
14 to remove CO_TwoReturned to Tower 1. Absorbent
In the upper part of the raw tower 15, CO separated from the absorbing solution_Two
Is the reflux water supplied from the nozzle 24 and the upper filling section 19
And is cooled by the regenerator reflux condenser 23, _Two
CO in the separator 21_TwoReflux of water vapor condensed with water
Separated from water and recovered CO_TwoCO from the discharge line 22_TwoTimes
Guided to the collection process. A part of the reflux water is returned to the reflux water pump 20
To return to the regeneration tower 15 and partly to the regeneration tower reflux water supply line.
De-CO through in 25_TwoRegeneration tower reflux water supply port 28 of tower 1
Supplied to This regenerating tower reflux water contains a small amount of absorbent.
Because it is rare, CO removal_TwoExhaust gas at upper filling section 3 of tower 1
Traces of CO contained in the exhaust gas_TwoFor elimination
Offer.

[0028]

The present invention will be described below in detail with reference to examples. (Example A, Comparative Example A) In a glass-made reaction vessel (flask) installed in a thermostat, 2-amine was used as the amine compound (X).
Amino-2-methyl-1-propanol (AMP), diethanolamine (DEA) and monoethanolamine (MEA), and the amine compound (Y) is a compound selected from 2- (methylamino) ethanol (MAE) and piperazine, respectively. Was mixed at the concentration shown in Table 1 as an absorbing solution, and a mixed gas (test gas) was passed through the flask at atmospheric pressure at a flow rate of 1 liter / min while stirring at a temperature of 40 ° C. The test gas was CO ₂ 10 mol%, O
₂ 3 mol% were used 40 ° C. model combustion exhaust gas having a composition of N ₂ 87 mole% (LNG-fired or equivalent). Continued throughout the test gas, at the time when the concentration of CO ₂ out gas become equal, the CO ₂ contained in the absorbing solution was measured using a CO ₂ analyzer (total organic carbon meter), CO ₂ saturated absorption amount (Nm ³ C
O ₂ / m ³ solution, molar CO ₂ / mol solution). Further, from the graph of the relationship between the CO ₂ concentration in the gas at the outlet of the flask and the aeration time, the tangent slope at the start of aeration was determined,
The initial absorption rate of CO _{2 in the} absorbing solution was determined by the ratio of the concentration of the amine compound (X) to the initial absorption rate in the MEA aqueous solution having the same concentration. The same test as above was performed at a temperature of 60 ° C. As a comparative example, the amine compound (X) alone, that is,
The absorption test of each aqueous solution of MEA, DEA and AMP
C., 60.degree. C. and 80.degree.

The obtained results are shown in Tables 1 to 3 and FIG.
FIG. 2 shows the effect of adding amine compound (Y) at a temperature of 40 ° C., using DEA as amine compound (X), taking the concentration of MAE and piperazine as the amine compound (Y) on the horizontal axis and the absorption reaction rate ratio on the vertical axis. showed that.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

Further, the CO ₂ absorption amount (Nm ³ CO ₂ / m
FIG. 3 shows the relationship between ( ³ absorbents) and temperature. From FIG. 3, AM
It can be seen that when P is mixed with 2-methylaminoethanol and used, the decrease in the amount of CO ₂ absorption due to an increase in the temperature of the absorbing solution is greater than when MEA is used. This indicates that thermal energy can be saved more in the regeneration of the absorbing solution than in the case of using the MEA.

(Example B, Comparative Example B) The effect of the reaction accelerator was measured using a wet-wall type absorption tower having a diameter of 15 mm and a length of 7.5 m , which is a model of an absorption tower used in actual processes. Tested. Absorbent is 30% by weight of DEAE
The solution was used, and the actual flue gas of the boiler (9 mol% of CO _{2, 2} mol% of O ₂ , the saturated amount of water vapor was contained, and the remaining mol% of N ₂ ) was used as the combustion exhaust gas, and L / G = 2.0 liters / M ³ N, the temperature of the liquid and the gas were both kept at 40 ° C., and the test was performed at a gas flow rate of 3.1 m / sec. FIG. 4 shows the results. The vertical axis in FIG. 4 indicates the CO ₂ absorption rate from the supplied combustion exhaust gas,
The horizontal axis shows the concentration of piperazine added to the absorption solution. FIG. 4 clearly shows the effect of piperazine on DEAE for promoting the absorption reaction.

As is evident from the above results, the use of the amine compound (X) in a relatively small amount mixed with the amine compound (X) according to the present invention makes it possible to obtain an earlier reaction than when the amine compound (X) is used alone. A significant increase in the absorption rate is achieved. In addition, the CO ₂ absorption amount per unit mol of (X) of the mixed absorption liquid is larger than that in the case of using MEA.

[0036]

As described above in detail, by using a mixed aqueous solution of a specific amine compound (X) and a specific amine compound (Y) as an absorbing solution in flue gas under atmospheric pressure by the method of the present invention, than that using amine compound (X) alone, a significant improvement in terms of the absorption rate of CO ₂ is achieved. Further, as compared with the case of using the MEA, it was decided that the CO ₂ can be efficiently removed even in terms of absorption and regeneration energy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a process that can be employed in the present invention.

FIG. 2 shows the effect of adding an amine compound (Y) in an absorbent using DEA.

FIG. 3 shows the absorption amount of the absorbing solution (Nm ³ CO ₂ / m ³ absorbing solution,
4 is a chart showing the relationship between the vertical axis) and temperature (° C., horizontal axis).

FIG. 4 shows the effect of adding piperazine to an absorbent using DEAE.

[Explanation of symbols]

1 CO ₂ removal tower 15 Absorbent regeneration tower 18 Regeneration heater

Continued on the front page (72) Inventor Shigeru Shimojo 3-3-22 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Inside Kansai Electric Power Co., Inc. (72) Inventor Mutsunori Karasaki 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Heavy Industries, Ltd. Company headquarters (72) Inventor Masaki Iijima 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Heavy Industries, Ltd.Headquarters (72) Inventor Toru Seto 4-622 Kannonshinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. (72) Inventor Kaoru Mitsuoka 4-62-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (56) References JP-A-53-100171 (JP, A) Hei 2-5044367 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B01D 53/62

Claims (4)

(57) [Claims] (A) A molecule having one alcoholic hydroxyl group and a primary amino group in the molecule, and the primary amino group is bonded to a tertiary carbon atom having two unsubstituted alkyl groups. compounds were those, and 及 beauty (C) an amine compound selected from the group consisting of diethanolamine (X 1) 100 parts by weight, (D) piperazine, (E) piperidine, (F) morpholine, (G) glycine, (H) 2-piperidinoethanol, and (I) having one alcoholic hydroxyl group and a secondary amino group in the molecule, wherein the secondary amino group has 2 or more carbon atoms including a bonding carbon atom. N bonded to a group having a chain
An amine compound selected from the group consisting of compounds having an atom and an unsubstituted alkyl group having 3 or less carbon atoms (Y
1 ) A method for removing carbon dioxide in flue gas, which comprises bringing 1 to 25 parts by weight of a mixed aqueous solution into contact with flue gas at atmospheric pressure. (B) an alcoholic hydroxyl group in the molecule.
Has one and a tertiary amino group, and is bonded to the tertiary amino group.
And at least two or more groups each include its bonding carbon atom.
At least a chain having at least 2 carbon atoms, further comprising a tertiary amino group
Two of the groups bonded to are unsubstituted alkyl groups
Compound (X2) 100 selected from the group consisting of
Parts by weight, (D) piperazine, (E) piperidine,
(F) morpholine, (G) glycine, and (H) 2-
Amine compound selected from the group of piperidinoethanol
(Y2) 1 to 25 parts by weight of a mixed aqueous solution and combustion under atmospheric pressure
Contacting with the exhaust gas.
How to remove carbon dioxide. 3. 2-amino-2-methyl-1,3-pro
Pandiol, 2-amino-2-methyl-1-propano
, 2-amino-2-ethyl-1,3-propanedio
And 2-amino-2-hydroxymethyl-1,3-
An amine compound selected from the group of propanediol (X
3) 100 parts by weight, piperazine, piperidine, morph
, Glycine, 2-methylaminoethanol, 2-
Piperidinoethanol and 2-ethylaminoethanol
1 to 25 parts by weight of an amine compound (Y3) selected from the group consisting of
Contact with the flue gas at atmospheric pressure
For removing carbon dioxide in flue gas, characterized by the following:
Law. 4. Consisting of t-butyldiethanolamine
100 parts by weight of the amine compound (X4), piperazine,
Peridine, morpholine, glycine and 2-piperidino
Amine compounds (Y4) 1 to 1 selected from the group of ethanol
Contacting 25 parts by weight of the mixed aqueous solution with flue gas at atmospheric pressure
The carbon dioxide in the flue gas,
How to remove.