WO2015005302A1 - Method for decomposing nitrosated amine, and method for recovering carbon dioxide from gas to be treated - Google Patents

Method for decomposing nitrosated amine, and method for recovering carbon dioxide from gas to be treated Download PDF

Info

Publication number
WO2015005302A1
WO2015005302A1 PCT/JP2014/068109 JP2014068109W WO2015005302A1 WO 2015005302 A1 WO2015005302 A1 WO 2015005302A1 JP 2014068109 W JP2014068109 W JP 2014068109W WO 2015005302 A1 WO2015005302 A1 WO 2015005302A1
Authority
WO
WIPO (PCT)
Prior art keywords
amine
amines
decomposing
carbon dioxide
treated
Prior art date
Application number
PCT/JP2014/068109
Other languages
French (fr)
Japanese (ja)
Inventor
横山　公一
成仁 高本
宮本　英治
島村　潤
Original Assignee
バブコック日立株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by バブコック日立株式会社 filed Critical バブコック日立株式会社
Publication of WO2015005302A1 publication Critical patent/WO2015005302A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
    • C07C213/08—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reactions not involving the formation of amino groups, hydroxy groups or etherified or esterified hydroxy groups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1425—Regeneration of liquid absorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1456—Removing acid components
    • B01D53/1475—Removing carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/20—Organic absorbents
    • B01D2252/204—Amines
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/40—Capture or disposal of greenhouse gases of CO2
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Definitions

  • the present invention relates to a method for decomposing amine nitrosates and a method for recovering carbon dioxide in a gas to be treated. More specifically, the present invention relates to a method for decomposing a nitroso compound derived from amines used for recovery of carbon dioxide in a gas discharged from a combustion apparatus such as a boiler, and a carbon dioxide absorbing liquid containing amines. The present invention relates to a method for recovering carbon dioxide in a gas to be treated with high efficiency by decomposing a nitrosate of amines that may be by-produced therein.
  • the combustion exhaust gas contains acidic gas components such as HCl (hydrogen chloride), NO x (nitrogen oxide), and SO x ; oxygen, nitrogen, water vapor, and the like.
  • acidic gas components such as HCl (hydrogen chloride), NO x (nitrogen oxide), and SO x ; oxygen, nitrogen, water vapor, and the like.
  • HCl hydrogen chloride
  • NO x nitrogen oxide
  • SO x sulfur oxide
  • oxygen, nitrogen, water vapor, and the like oxygen, nitrogen, water vapor, and the like.
  • organic acid salts and inorganic acid salts are thermally stable salts (hereinafter, sometimes referred to as heat stable salts). Thermally stable salts corrode metals and reduce the ability to absorb CO 2 . Such heat stable salts are removed by reclaiming or the like.
  • the absorbent containing amines may be partially nitrosated while being used to recover carbon dioxide from combustion exhaust gas. Since nitrosated products of amines have lower carbon dioxide absorption than amines and reduce the recovery efficiency of carbon dioxide, various studies have been conducted to remove the nitrosated products. For example, Patent Document 2 discloses a method of decomposing by heating nitrosamine.
  • nitrosamines have higher boiling points than the original amines.
  • the boiling point of N-nitrosodimethylamine produced by nitrosation of dimethylamine is 151 to 154 ° C.
  • the boiling point of N-nitrosodiethylamine produced by nitrosation of diethylamine is 177 ° C.
  • thermal decomposition method of amine nitrosates amines, which are the main components of the absorbing solution, are also thermally decomposed together, resulting in a large loss of amines.
  • thermally stable nitrosates of amines need to be heated at a temperature higher than that of conventional reclaimers and reboilers for thermal decomposition, so additional equipment may be required. .
  • the object of the present invention is to provide a nitrosated product of amines produced as a by-product in the absorption liquid (hereinafter referred to as “amines”) without installing any additional equipment and without substantially decomposing amines having CO 2 absorption ability.
  • amines a nitrosated product of nitroso
  • nitroso compound (A) to provide a method for efficiently decomposing it into amines.
  • [10] including heating the liquid to be treated containing a nitrosated product of amines to a pH of less than 3 at a temperature not lower than the boiling point of water and not higher than the boiling point of the amines; A method for decomposing amine nitrosates.
  • Part of the regenerated CO 2 lean absorbent is regenerated in steps (III) and (II) in the presence of hydrohalic acid at a temperature above the boiling point of water and below the boiling point of amines.
  • the nitrosated products of amines by-produced in the absorption liquid can be efficiently obtained without installing new additional equipment and without substantially decomposing amines having CO 2 absorption ability. It can be decomposed to amines.
  • the liquid to be treated containing the nitroso compound (A) is made to have a pH of less than 3 and a temperature not lower than the boiling point of water and not higher than the boiling point of the amines. Heating.
  • the method of making the liquid to be treated be less than pH 3.
  • the pH can be reduced to less than 3 by adding an inorganic acid such as hydrohalic acid, sulfuric acid or nitric acid, or an organic acid such as formic acid, oxalic acid or acetic acid to the liquid to be treated.
  • a method for decomposing amine nitrosates wherein a liquid to be treated containing a nitroso compound (A) is at least the boiling point of water in the presence of hydrohalic acid and the amines. It includes heating at a temperature below the boiling point.
  • amines include primary amines, secondary amines, and tertiary amines.
  • primary amine include monoalkanolamines such as monomethanolamine and monoethanolamine; alkylamines such as methylamine and ethylamine.
  • Secondary amines include dialkylamines such as dimethylamine, diethylamine, methylethylamine, t-butylethylamine and dibutylamine; dialkanolamines such as dimethanolamine and diethanolamine; N-methyl-N- (hydroxyethyl) amine, N N- such as -ethyl-N- (hydroxyethyl) amine, N-ethyl-N- (hydroxybutyl) amine, N-isopropyl-N- (hydroxyethyl) amine, N-methyl-N- (hydroxypropyl) amine Alkyl-N- (hydroxyalkyl) amine; cyclic amines such as heptamethyleneimine, piperazine, piperidine, morpholine, and the like.
  • tertiary amine examples include trialkylamines such as trimethylamine and triethylamine, trialkanolamines such as trimethanolamine and triethanolamine; and cyclic amines such as quinuclidine and pyridine.
  • trialkylamines such as trimethylamine and triethylamine
  • trialkanolamines such as trimethanolamine and triethanolamine
  • cyclic amines such as quinuclidine and pyridine.
  • alkanolamines are preferable, and N-hydroxyalkylamine and N-alkyl-N-hydroxyalkylamine are more preferable.
  • R is an N-substituent such as an alkyl group or a hydroxyalkyl group.
  • these tautomers are also included in the nitroso compound (A).
  • the nitrosoalkane may be a dimer, and in the present invention, this dimer is also included in the nitroso compound (A).
  • this tautomer is also included in the nitroso compound (A).
  • nitroso compound (A) examples include N-nitrosodiethanolamine, N-nitrosoheptamethyleneimine, N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosomethylhydroxyethylamine, N-ethyl-N- (2- Hydroxyethyl) nitrosamine, N-tert-butyl-N-ethylnitrosamine, N-nitrosodibutylamine, N-ethyl-N- (4-hydroxybutyl) nitrosamine, N-butyl-N- (4-hydroxybutyl) nitrosamine, N-nitrosomorpholine etc. are mentioned. Of these, the nitroso compound (A) that is dissolved or mixed in water is preferably used as the decomposition target of the method according to the present invention.
  • an aqueous amine solution used for absorbing carbon dioxide in the combustion exhaust gas (hereinafter sometimes referred to as an absorbing liquid) is preferably used.
  • the absorbing liquid is an aqueous solution containing at least amines as main components and a nitroso compound (A) as impurities.
  • the decomposition method of the present invention is performed after concentrating the nitroso compound (A) by distilling off the amines from the liquid to be treated. It is preferable. If the amount of amines in the liquid to be treated is small, the amount of hydrohalic acid consumed by the reaction with the amines is reduced, and the amount of hydrohalic acid added for decomposition can be reduced. In addition, amines that are unnecessarily decomposed by heating to decompose the nitroso compound (A) can be reduced. It is also preferable to reduce the amount of water in the liquid to be treated. This is because, as will be described later, nitrile halide produced as a by-product reacts with water to produce nitrous acid, and this nitrous acid may nitrosate amines again.
  • the hydrohalic acid used in the present invention is not particularly limited. Examples thereof include at least one selected from the group consisting of hydrochloric acid, hydrobromic acid, and hydroiodic acid.
  • the amount of hydrohalic acid is preferably 100 mol parts or more relative to 100 mol parts of the total amount of amino groups and nitroso groups as the amount of hydrogen halide.
  • the amount of nitroso group includes the amount of tautomers.
  • the amines regenerated from the nitroso compound (A) react with the hydrogen halide to form a heat-stable salt, and the nitroso compound Unnecessary thermal decomposition of amines regenerated from (A) can be prevented.
  • the pH of the liquid to be treated is preferably less than 5, more preferably less than 3, and even more preferably less than 2.
  • the decomposition of the nitroso compound (A) is performed by heating to a temperature not lower than the boiling point of water and not higher than the boiling point of the amines.
  • the details of the decomposition process of the nitroso compound (A) according to the present invention are not clear, but it is assumed that it is decomposed by a chemical reaction as shown in the following formula, for example. By this decomposition, the nitroso compound (A) can be regenerated to the original amines.
  • YNO nitrosyl halide produced as a by-product in this decomposition reaction produces nitrous acid as a by-product by reaction with water. Heating above the boiling point of water vaporizes the water, reducing the opportunity for reaction between water and nitrile halide and suppressing the production of nitrous acid.
  • halogenated nitrosyl has a boiling point, for example, nitrosyl chloride is ⁇ 6.4 ° C., which is often lower than amines. Therefore, by adjusting the heating temperature for decomposing the nitroso compound (A), the nitrosyl halide is reduced. It can be removed by vaporization.
  • the heating temperature is preferably as low as possible.
  • the pressure is set to a pressure below atmospheric pressure, preferably the boiling point of water suppresses the thermal decomposition of amines. It is preferable to heat by lowering the pressure to a sufficient temperature or lower, more preferably to a pressure at which the boiling point of the mixture of the liquid to be treated containing nitrosated amines and hydrohalic acid is 100 ° C. or lower.
  • a method for recovering carbon dioxide in a gas to be treated comprises contacting a gas to be treated containing carbon dioxide with a CO 2 lean absorbing solution containing amines to convert the carbon dioxide into CO 2 lean. is absorbed in the absorbing liquid, to obtain a CO 2 rich absorbent solution (I), the step of carbon dioxide by heating the CO 2 rich absorbent solution desorbed to play CO 2 lean absorbing solution (II), is reproduced A part of the CO 2 lean absorbing solution was regenerated in steps (III) and (II) in which heating was performed in the presence of hydrohalic acid above the boiling point of water and below the boiling point of amines. A step (IV) of supplying the remainder of the CO 2 lean absorbing solution and / or the CO 2 lean absorbing solution heated in the step (III) to the carbon dioxide absorbing step (I).
  • step (I), step (II) and step (IV) are usually performed continuously and simultaneously.
  • the gas 11 to be treated is supplied to the bottom 3 of the absorption tower 1 by the blower 12, rises in the packed bed 2, and is discharged as a treated gas 4 from the top.
  • the gas to be treated 11 may have a pressure equal to or higher than normal pressure, or may be normal pressure.
  • the temperature of the gas to be treated 11 is preferably 100 ° C. or lower.
  • a CO 2 lean absorbing liquid containing amines is poured from the nozzle 6 onto the top of the packed bed 2 and comes into contact with the gas to be treated in the packed bed 2 to absorb carbon dioxide in the gas to be treated, and the bottom of the absorption tower Accumulate at 10.
  • the liquid accumulated in the bottom 10 is rich in carbon dioxide and is called a CO 2 rich absorption liquid.
  • a reboiler 23 is installed at the bottom of the tower. Steam vaporized by the reboiler ascends the packed bed 2 and heats the CO 2 rich absorbent that descends the packed bed 2 to desorb carbon dioxide.
  • the desorbed carbon dioxide is removed by mist in the water washing section 26 and discharged from the top of the desorption tower. Further, water is recovered by the separator 17, carbon dioxide is sent to the next step through the pipe 18, and the recovered water is supplied to the water washing section 26 of the desorption tower or the nozzle 9 at the top of the absorption tower.
  • the step (III) may be performed continuously continuously, but it is preferable from the viewpoint of energy saving that the step (III) is performed temporarily when the CO 2 absorption capacity of the absorbing solution is lowered.
  • the decrease in the CO 2 absorption capacity of the absorbing solution is caused by an increase in the amount of heat-stable salt and / or nitroso compound (A) in the absorbing solution, as already described.
  • the amount of the heat stable salt and the nitroso compound (A) in the absorbing solution can be measured by a known method.
  • the CO 2 lean absorbent extracted from the bottom of the desorption tower 13 is heated by the heat transfer tube of the reclaiming device 24.
  • the amines and water contained in the CO 2 lean absorbent are vaporized and returned to the desorption tower.
  • the heat stable salt and nitroso compound (A) are concentrated. Hydrohalic acid is supplied to the concentrated liquid, and the concentrated liquid is heated in the presence of hydrohalic acid. In this way, the nitroso compound (A) is regenerated into amines before nitrosation.
  • the heating temperature is not lower than the boiling point of water and not higher than the boiling point of the amines.
  • the pressure during heating is preferably not more than atmospheric pressure.
  • the regenerated amines are vaporized and returned to the desorption tower.
  • the amines that cannot be returned react with hydrohalic acid to form heat stable salts.
  • the regenerated amines can be vaporized and returned to the desorption tower.
  • the equipment used in the examples is an example, and does not limit the scope of implementation. For example, similar results can be obtained by using other equipment such as a mantle heater or a ribbon heater for heating the liquid, a round bottom flask as a container, and a Liebig tube as a cooling pipe.
  • the amount of the nitroso compound was measured with a GC (gas chromatograph) -TEA (thermal energy analysis) apparatus (TEA-800 manufactured by Ellutia).
  • the amount of the amine compound was measured by an ion chromatograph (ICS-1500, manufactured by DIONEX).
  • the amount of the amine compound includes an amount obtained by converting amine chloride into an amine compound by weight.
  • Example 1 It implemented using the apparatus shown in FIG. Diethanolamine (C 4 H 11 NO 2 , DEA, molecular weight 105 g / mol, boiling point 268.8 ° C (according to Showa Chemical MSDS)) 8.5 parts by mass (80.95 parts by mole), moisture 1.499 parts by weight, and nitrosodiethanolamine (C 4 H 10 N A mixed solution of 0.001 part by mass (0.007 mol part) of 2 O 3 , NDEA, molecular weight 134 g / mol) was prepared.
  • the flask 103 was immersed in an oil bath 101 in which silicone oil 102 adjusted to a temperature of 140 ° C. was stored, and the prepared solution was heated for 30 minutes.
  • the flask 103 is connected to the cooling pipe 105 via a connecting pipe 107.
  • the upper part of the flask 103 and the connecting pipe 107 are heated by the heater 106 so as not to condense.
  • the gas evaporated in the flask 103 was condensed in a cooling pipe 105 in which 20 ° C. cooling water 108 circulated, and the condensate 109 was collected in a collection bottle (not shown).
  • the amount of the nitroso compound contained in the condensate 109 and the amount of the nitroso compound contained in the liquid remaining in the flask 103 were measured, and the total was calculated.
  • the total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
  • the amount of amine compound contained in the condensate 109 and the amount of amine compound contained in the liquid remaining in the flask 103 were measured, and the total was calculated.
  • the total amount of the amine compound did not change from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Comparative Example 1 The same procedure as in Example 1 was performed except that 8.62 parts by mass of water was added instead of hydrochloric acid. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
  • Comparative Example 2 The same procedure as in Example 1 was performed except that the apparatus shown in FIG. 2 (heating at 280 ° C. with a mantle heater 206 instead of heating with the oil bath 101) was used. The total amount of nitroso compounds was below the detection limit. Moreover, the total amount of amine compounds was reduced to about 70%. That is, although the nitroso compound was completely decomposed, the amine compound useful for CO 2 absorption was also decomposed simultaneously with the decomposition of the nitroso compound.
  • Example 2 The same procedure as in Example 1 was performed except that the temperature of the silicone oil 102 was changed to 110 ° C. and the heating time was changed to 1 hour. The total amount of nitroso compounds was almost below the detection limit. That is, the nitroso compound was almost completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Comparative Example 3 The same procedure as in Example 1 was performed except that the temperature of the silicone oil 102 was changed to 90 ° C. and the heating time was changed to 1 hour. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
  • Comparative Example 4 The same procedure as in Example 2 was performed except that 8.62 parts by mass of water was added instead of hydrochloric acid. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
  • Example 3 It implemented by the same method as Example 2 except having added 14.2 mass parts (84.24 mol parts) of hydrobromic acid (hydrogen bromide concentration 48 mass%) instead of hydrochloric acid.
  • the total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
  • the total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Example 4 It implemented by the same method as Example 2 except having added 19.1 mass parts (85.11 mol parts) of hydroiodic acid (concentration of hydrogen iodide 57 mass%) instead of hydrochloric acid.
  • the total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
  • the total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Example 5 The same procedure as in Example 1 was carried out except that N-din-butylamine was used instead of diethanolamine and N-nitrosodin-butylamine (boiling point 237 ° C.) was used instead of nitrosodiethanolamine.
  • the total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
  • the total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Example 6 Use N-ethylaminoethanol instead of diethanolamine, and N-ethyl-N- (2-hydroxyethyl) nitrosamine (vapor pressure of 3 mmHg at 103 ° C) instead of nitrosodiethanolamine, and the temperature of silicone oil 102 to 103 ° C
  • the same method as in Example 1 was carried out except that the change was made.
  • the total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
  • the total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Example 7 Piperazine (divalent amine compound, molecular weight 86 g / mol) 1.0 part by mass (11.63 mol part), water 8.999 parts by mass, and 1-nitrosopiperazine (molecular weight 115 g / mol, boiling point 265 ° C.) 0.001 part by mass (0.009 mol part)
  • a mixed solution was prepared. The same procedure as in Example 1 was performed except that the mixed solution used in Example 1 was changed to the above mixed solution, and the amount of hydrochloric acid (hydrogen chloride concentration: 36 mass%) was changed to 2.53 parts by mass (25.0 mol parts). The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
  • Example 8 Compared except that the recovery bottle connected to the cooler 105 is connected to an aspirator (Yamato WP-15) and continuously evacuated to change the pressure in the flask 103 to 50 kPa absolute and the temperature of the cooling water to 4 ° C. Performed in the same manner as Example 3. At this time, the boiling point of water was about 82 ° C. The total amount of nitroso compounds was almost below the detection limit. That is, the nitroso compound was almost completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose. It was confirmed that the decomposition of the nitroso compound was promoted by lowering the pressure to the atmospheric pressure or lower even at a low temperature at which the decomposition of the nitroso compound did not proceed under atmospheric pressure (see Comparative Example 3).
  • Example 9 A mixed liquid of 9.999 parts by mass of water and 0.001 parts by mass (0.007 mol parts) of nitrosodiethanolamine was prepared. The same procedure as in Example 1 was performed except that the mixed solution used in Example 1 was changed to the above mixed solution, and the amount of hydrochloric acid (hydrogen chloride concentration: 36% by mass) was changed to 0.0112 parts by mass (0.11 mol part). The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. On the other hand, an amine compound that was not contained in the preparation solution was detected. It was confirmed that the amine compound was produced by decomposition of the nitroso compound.
  • hydrochloric acid hydrogen chloride concentration: 36% by mass
  • Example 10 The reclaiming apparatus shown in FIG. 3 was used.
  • the liquid 13 having the same composition as the prepared liquid prepared in Example 1 was put into the reclaiming container 308 through the supply port 311, and the liquid 13 was heated by supplying steam 301 at 140 ° C. to the heat transfer tube 309. During heating, the gas from the exhaust port 312 was cooled to 20 ° C. to recover the condensate.
  • the liquid remaining in the reclaiming container 308 after reclaiming was extracted from the outlet 310.
  • the amount of the nitroso compound contained in the condensate and the amount of the nitroso compound contained in the solution extracted from the outlet 310 were measured and the total was calculated. The total amount of nitroso compounds was below the detection limit.
  • the nitroso compound was completely decomposed. Further, the amount of the amine compound contained in the condensed liquid and the amount of the amine compound contained in the liquid extracted from the outlet 310 were measured and the total was calculated. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose. It was confirmed that the nitroso compound could be decomposed by the reclaiming device.

Abstract

A method for decomposing a nitrosated amine to regenerate the amine, the method comprising heating a liquid to be treated which contains a nitrosated amine, such as an aqueous amine solution used for absorbing carbon dioxide contained in a combustion discharge gas, at a temperature which is not lower than the boiling point of water and is not higher than the boiling point of the amine, either after the pH of the liquid to be treated is adjusted to a value less than 3 or in the presence of a hydrohalogenic acid such as hydrochloric acid or hydrobromic acid; and a method for recovering carbon dioxide from a gas to be treated, the method comprising using a CO2-absorbing liquid that contains the regenerated amine.

Description

アミン類のニトロソ化物を分解する方法、並びに被処理ガス中の二酸化炭素を回収する方法Method for decomposing amine nitrosates and method for recovering carbon dioxide in gas to be treated
　本発明は、アミン類のニトロソ化物を分解する方法、並びに被処理ガス中の二酸化炭素を回収する方法に関する。より詳細に、本発明は、ボイラなどの燃焼装置から排出されるガス中の二酸化炭素の回収に用いられているアミン類に由来するニトロソ化合物を分解する方法、並びにアミン類を含む二酸化炭素吸収液中に副生することがあるアミン類のニトロソ化物を分解して、高効率で被処理ガス中の二酸化炭素を回収する方法に関する。 The present invention relates to a method for decomposing amine nitrosates and a method for recovering carbon dioxide in a gas to be treated. More specifically, the present invention relates to a method for decomposing a nitroso compound derived from amines used for recovery of carbon dioxide in a gas discharged from a combustion apparatus such as a boiler, and a carbon dioxide absorbing liquid containing amines. The present invention relates to a method for recovering carbon dioxide in a gas to be treated with high efficiency by decomposing a nitrosate of amines that may be by-produced therein.
　火力発電所等においては化石燃料を燃焼させるので、二酸化炭素（CO2）が大量に発生する。二酸化炭素は、温暖化原因物質の一つとして、その排出量の抑制が各国で進められている。二酸化炭素を回収する方法として、現在、最も実用化に近い方法としてアルカノールアミンなどのアミン類を含む液による吸収方法が知られている（例えば、特許文献１など参照）。 In a thermal power plant or the like, fossil fuel is burned, so a large amount of carbon dioxide (CO 2 ) is generated. Carbon dioxide is one of the causes of global warming, and the suppression of its emission is being promoted in each country. As a method for recovering carbon dioxide, an absorption method using a liquid containing amines such as alkanolamine is known as the most practical method (see, for example, Patent Document 1).
　燃焼排ガスは、CO2以外に、HCl（塩化水素）、NOx（窒素酸化物）、SOx等の酸性ガス成分；　酸素、窒素、水蒸気などを含んでいる。この燃焼排ガスをアミン類を含む吸収液に接触させると、CO2の他に酸性ガス成分も吸収液に吸収される。酸性ガス成分がアミン類と結合すると無機酸塩を形成する。例えば、HClは塩酸塩を、NOxは硝酸塩などを、SO2は硫酸塩を形成する。また、アミン類の分解によって副生するギ酸、蓚酸、酢酸などの有機酸がアミン類と結合すると有機酸塩を形成する。このような有機酸塩や無機酸塩などは熱的に安定な塩（以後、熱安定性塩（Heat Stable Salt）ということがある。）である。熱安定性塩は、金属を腐食させたり、CO2の吸収能力を低下させたりする。このような熱安定性塩は、リクレーミングなどによって除去されている。 In addition to CO 2 , the combustion exhaust gas contains acidic gas components such as HCl (hydrogen chloride), NO x (nitrogen oxide), and SO x ; oxygen, nitrogen, water vapor, and the like. When this combustion exhaust gas is brought into contact with an absorbing solution containing amines, an acidic gas component in addition to CO 2 is also absorbed by the absorbing solution. When the acid gas component is combined with amines, an inorganic acid salt is formed. For example, HCl forms a hydrochloride, NO x forms a nitrate, etc., and SO 2 forms a sulfate. Further, when an organic acid such as formic acid, succinic acid, or acetic acid by-produced by decomposition of amines is combined with amines, an organic acid salt is formed. Such organic acid salts and inorganic acid salts are thermally stable salts (hereinafter, sometimes referred to as heat stable salts). Thermally stable salts corrode metals and reduce the ability to absorb CO 2 . Such heat stable salts are removed by reclaiming or the like.
　アミン類を含む吸収液は、燃焼排ガスからの二酸化炭素の回収に使用している間に、アミン類の一部がニトロソ化することがある。アミン類のニトロソ化物は、アミン類に比べて二酸化炭素の吸収が低く、二酸化炭素の回収効率を低下させるので、該ニトロソ化物を除去する検討が種々行われている。例えば、特許文献２は、ニトロソアミンを加熱して分解する方法を開示している。 The absorbent containing amines may be partially nitrosated while being used to recover carbon dioxide from combustion exhaust gas. Since nitrosated products of amines have lower carbon dioxide absorption than amines and reduce the recovery efficiency of carbon dioxide, various studies have been conducted to remove the nitrosated products. For example, Patent Document 2 discloses a method of decomposing by heating nitrosamine.
　多くのニトロソアミン類は元のアミン類に比べて沸点が高い。例えば、ジメチルアミン（沸点7.0℃）のニトロソ化で生成するＮ－ニトロソジメチルアミンの沸点は151～154℃であり、ジエチルアミン（沸点55.5℃）のニトロソ化で生成するＮ－ニトロソジエチルアミンの沸点は177℃である。アミン類のニトロソ化物の熱分解法においては、吸収液の主成分であるアミン類も一緒に熱分解してしまうので、アミン類の損失が多い。また、熱的に安定なアミン類のニトロソ化物は、熱分解のために、従来のリクレーマやリボイラによる加熱温度よりも高い温度で加熱する必要があるので、追加の設備が必要となることがある。 Many nitrosamines have higher boiling points than the original amines. For example, the boiling point of N-nitrosodimethylamine produced by nitrosation of dimethylamine (boiling point 7.0 ° C.) is 151 to 154 ° C., and the boiling point of N-nitrosodiethylamine produced by nitrosation of diethylamine (boiling point 55.5 ° C.) is 177 ° C. In the thermal decomposition method of amine nitrosates, amines, which are the main components of the absorbing solution, are also thermally decomposed together, resulting in a large loss of amines. Also, thermally stable nitrosates of amines need to be heated at a temperature higher than that of conventional reclaimers and reboilers for thermal decomposition, so additional equipment may be required. .
特許第３５２９８５５号Japanese Patent No. 3529855 ＷＯ２０１２／１０４１３７WO2012 / 104137
　本発明の目的は、新たな追加設備を設置すること無く、またCO2吸収能力を有するアミン類をほとんど分解させずに、吸収液中に副生したアミン類のニトロソ化物（以下、「アミン類のニトロソ化物」を「ニトロソ化合物(A)」ということがある。）を効率的に分解してアミン類にするための方法を提供することである。 The object of the present invention is to provide a nitrosated product of amines produced as a by-product in the absorption liquid (hereinafter referred to as “amines”) without installing any additional equipment and without substantially decomposing amines having CO 2 absorption ability. The nitrosated product of nitroso is sometimes referred to as “nitroso compound (A)”) to provide a method for efficiently decomposing it into amines.
　本発明者らは上記目的を達成するために検討した結果、以下の形態を包含する本発明を完成するに至った。 As a result of investigations to achieve the above object, the present inventors have completed the present invention including the following modes.
〔１〕アミン類のニトロソ化物を含む被処理液を、ハロゲン化水素酸の存在下、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む、
アミン類のニトロソ化物の分解方法。 (1) heating a liquid to be treated containing a nitrosated product of amines in the presence of hydrohalic acid at a temperature not lower than the boiling point of water and not higher than the boiling point of the amines;
A method for decomposing amine nitrosates.
〔２〕被処理液はアミン類をさらに含む、〔１〕に記載のアミン類のニトロソ化物の分解方法。
〔３〕ハロゲン化水素の量が、アミノ基及びニトロソ基の合計量100モル部に対して、100モル部以上である、〔２〕に記載のアミン類のニトロソ化物の分解方法。
〔４〕被処理液が、燃焼排ガス中の二酸化炭素を吸収するために用いられたアミン類水溶液である、〔１〕～〔３〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。
〔５〕ハロゲン化水素酸が、塩酸、臭化水素酸、およびヨウ化水素酸からなる群より選ばれる少なくとも一つである、〔１〕～〔４〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。 [2] The method for decomposing a nitrosated product of an amine according to [1], wherein the liquid to be treated further contains an amine.
[3] The method for decomposing amine nitrosates according to [2], wherein the amount of hydrogen halide is 100 mol parts or more with respect to 100 mol parts of the total amount of amino groups and nitroso groups.
[4] The method for decomposing amine nitrosates according to any one of [1] to [3], wherein the liquid to be treated is an aqueous amine solution used to absorb carbon dioxide in combustion exhaust gas. .
[5] The amines according to any one of [1] to [4], wherein the hydrohalic acid is at least one selected from the group consisting of hydrochloric acid, hydrobromic acid, and hydroiodic acid. Method for decomposing nitrosates.
〔６〕前記加熱を、大気圧以下の圧力にて行う、〔１〕～〔５〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。
〔７〕前記加熱を、アミン類のニトロソ化物を含む被処理液とハロゲン化水素酸との混合物の沸点が１００℃以下になる圧力にて行う、〔１〕～〔５〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。
〔８〕アミン類がアルカノールアミン類である〔１〕～〔７〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。
〔９〕ハロゲン化水素酸の存在下での加熱の後、アルカリ成分の存在下で加熱することをさらに含む〔１〕～〔８〕のいずれかひとつに記載のアミン類のニトロソ化物の分解方法。 [6] The method for decomposing a nitrosated product of an amine according to any one of [1] to [5], wherein the heating is performed at a pressure lower than atmospheric pressure.
[7] In any one of [1] to [5], the heating is performed at a pressure at which a boiling point of a mixture of the liquid to be treated containing nitrosated amines and hydrohalic acid is 100 ° C. or lower. A method for decomposing nitrosated compounds of the amines described.
[8] The method for decomposing a nitrosated product of an amine according to any one of [1] to [7], wherein the amine is an alkanolamine.
[9] The method for decomposing a nitrosated product of an amine according to any one of [1] to [8], further comprising heating in the presence of an alkali component after heating in the presence of hydrohalic acid. .
〔１０〕　アミン類のニトロソ化物を含む被処理液を、ｐＨ３未満にして、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む、
アミン類のニトロソ化物の分解方法。 [10] including heating the liquid to be treated containing a nitrosated product of amines to a pH of less than 3 at a temperature not lower than the boiling point of water and not higher than the boiling point of the amines;
A method for decomposing amine nitrosates.
〔１１〕二酸化炭素を含む被処理ガスとアミン類を含むCO2リーン吸収液とを接触させて、二酸化炭素をCO2リーン吸収液に吸収させて、CO2リッチ吸収液を得る工程(I)、
　CO2リッチ吸収液を加熱して二酸化炭素を脱離させてCO2リーン吸収液に再生する工程(II)、
　再生されたCO2リーン吸収液の一部を、ハロゲン化水素酸の存在下に、水の沸点以上で且つアミン類の沸点以下にて、加熱する工程(III)、および
　工程(II)で再生されたCO2リーン吸収液の残部および／または工程(III)で加熱されたCO2リーン吸収液を前記二酸化炭素吸収工程(I)に供給する工程(IV)、
　を有する被処理ガス中の二酸化炭素を回収する方法。 [11] A step (I) in which a gas to be treated containing carbon dioxide is brought into contact with a CO 2 lean absorbing solution containing amines to absorb carbon dioxide in the CO 2 lean absorbing solution to obtain a CO 2 rich absorbing solution. ,
A step of heating the CO 2 rich absorbent to desorb carbon dioxide and regenerating it into a CO 2 lean absorbent (II),
Part of the regenerated CO 2 lean absorbent is regenerated in steps (III) and (II) in the presence of hydrohalic acid at a temperature above the boiling point of water and below the boiling point of amines. A step (IV) of supplying the remainder of the CO 2 lean absorbent and / or the CO 2 lean absorbent heated in step (III) to the carbon dioxide absorption step (I),
A method for recovering carbon dioxide in a gas to be treated.
〔１２〕工程(III)で加熱されたCO2リーン吸収液をアルカリ成分の存在下で加熱する工程(V)をさらに有する〔１１〕に記載の被処理ガス中の二酸化炭素を回収する方法。 [12] The method for recovering carbon dioxide in the gas to be treated according to [11], further comprising a step (V) of heating the CO 2 lean absorbent heated in the step (III) in the presence of an alkali component.
　本発明の方法によれば、新たな追加設備を設置すること無く、またCO2吸収能力を有するアミン類をほとんど分解させずに、吸収液中に副生したアミン類のニトロソ化物を効率的に分解してアミン類にすることができる。  According to the method of the present invention, the nitrosated products of amines by-produced in the absorption liquid can be efficiently obtained without installing new additional equipment and without substantially decomposing amines having CO 2 absorption ability. It can be decomposed to amines.
ニトロソ化合物(A)の分解方法を実施するための装置の一実施形態を示す図である。It is a figure which shows one Embodiment of the apparatus for implementing the decomposition | disassembly method of a nitroso compound (A). ニトロソ化合物(A)の分解方法を実施するための装置の一実施形態を示す図である。It is a figure which shows one Embodiment of the apparatus for implementing the decomposition | disassembly method of a nitroso compound (A). ニトロソ化合物(A)の分解方法を実施するためのリクレーミング装置の一実施形態を示す図である。It is a figure which shows one Embodiment of the reclaiming apparatus for enforcing the decomposition | disassembly method of a nitroso compound (A). 本発明の二酸化炭素回収方法を実施するための装置の一実施形態を示す図である。It is a figure which shows one Embodiment of the apparatus for implementing the carbon dioxide collection method of this invention.
　本発明の一実施形態に係るアミン類のニトロソ化物の分解方法は、ニトロソ化合物(A)を含む被処理液を、ｐＨ３未満にして、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む。被処理液をｐＨ３未満にする手法は特に限定されない。例えば、ハロゲン化水素酸、硫酸、硝酸などの無機酸や、ギ酸、シュウ酸、酢酸などの有機酸を被処理液に添加することによって、ｐＨを３未満にすることができる。 In the method for decomposing amine nitrosates according to one embodiment of the present invention, the liquid to be treated containing the nitroso compound (A) is made to have a pH of less than 3 and a temperature not lower than the boiling point of water and not higher than the boiling point of the amines. Heating. There is no particular limitation on the method of making the liquid to be treated be less than pH 3. For example, the pH can be reduced to less than 3 by adding an inorganic acid such as hydrohalic acid, sulfuric acid or nitric acid, or an organic acid such as formic acid, oxalic acid or acetic acid to the liquid to be treated.
　本発明の別の一実施形態に係るアミン類のニトロソ化物の分解方法は、ニトロソ化合物(A)を含む被処理液を、ハロゲン化水素酸の存在下、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む。 According to another embodiment of the present invention, there is provided a method for decomposing amine nitrosates, wherein a liquid to be treated containing a nitroso compound (A) is at least the boiling point of water in the presence of hydrohalic acid and the amines. It includes heating at a temperature below the boiling point.
　アミン類としては、一級アミン、二級アミン、三級アミンなどが挙げられる。
　一級アミンとしては、モノメタノールアミン、モノエタノールアミンなどのモノアルカノールアミン；メチルアミン、エチルアミンなどのアルキルアミンなどが挙げられる。
　二級アミンとしては、ジメチルアミン、ジエチルアミン、メチルエチルアミン、t-ブチルエチルアミン、ジブチルアミンなどのジアルキルアミン；ジメタノールアミン、ジエタノールアミンなどのジアルカノールアミン；N-メチル-N-（ヒドロキシエチル）アミン、N-エチル-N-（ヒドロキシエチル）アミン、N-エチル-N-（ヒドロキシブチル）アミン、N-イソプロピル-N-（ヒドロキシエチル）アミン、N-メチル-N-（ヒドロキシプロピル）アミンなどのN-アルキル-N-（ヒドロキシアルキル）アミン；ヘプタメチレンイミン、ピペラジン、ピペリジン、モルホリンなどの環状アミンなどが挙げられる。
　三級アミンとしては、トリメチルアミン、トリエチルアミンなどのトリアルキルアミン、トリメタノールアミン、トリエタノールアミンなどのトリアルカノールアミン；キヌクリジン、ピリジンなどの環状アミンなどが挙げられる。
　これらのうち、アルカノールアミン類が好ましく、N-ヒドロキシアルキルアミン、N-アルキル-N-ヒドロキシアルキルアミンがより好ましい。 Examples of amines include primary amines, secondary amines, and tertiary amines.
Examples of the primary amine include monoalkanolamines such as monomethanolamine and monoethanolamine; alkylamines such as methylamine and ethylamine.
Secondary amines include dialkylamines such as dimethylamine, diethylamine, methylethylamine, t-butylethylamine and dibutylamine; dialkanolamines such as dimethanolamine and diethanolamine; N-methyl-N- (hydroxyethyl) amine, N N- such as -ethyl-N- (hydroxyethyl) amine, N-ethyl-N- (hydroxybutyl) amine, N-isopropyl-N- (hydroxyethyl) amine, N-methyl-N- (hydroxypropyl) amine Alkyl-N- (hydroxyalkyl) amine; cyclic amines such as heptamethyleneimine, piperazine, piperidine, morpholine, and the like.
Examples of the tertiary amine include trialkylamines such as trimethylamine and triethylamine, trialkanolamines such as trimethanolamine and triethanolamine; and cyclic amines such as quinuclidine and pyridine.
Of these, alkanolamines are preferable, and N-hydroxyalkylamine and N-alkyl-N-hydroxyalkylamine are more preferable.
　本発明に用いられる被処理液に含まれるニトロソ化合物(A)としては、一級アミン（RNH2）の酸化などで生成するR-N=Oで表されるニトロソ化合物〔ニトロソアルカン類〕、一級アミン（RNH2）または二級アミン（R2NH）と亜硝酸との反応などで生成するRNH-N=OまたはR2N-N=Oで表されるN-ニトロソ化合物〔N-ニトロソアミン類〕などが挙げられる。但し、Rはアルキル基、ヒドロキシアルキル基などのN-置換基である。R-N=Oで表されるニトロソ化合物はRが一級アルキル基または二級アルキル基であるときオキシムに変異していることもあるが、本発明ではこれら互変異体もニトロソ化合物(A)に含める。また、ニトロソアルカンは二量体になっていることもあるが、本発明ではこの二量体もニトロソ化合物(A)に含める。RNH-N=Oで表されるN-ニトロソアミンは不安定な物質で室温において分解しジアゾヒドロキシドに変異するが、本発明ではこの互変異体もニトロソ化合物(A)に含める。 The nitroso compound (A) contained in the liquid to be treated used in the present invention includes nitroso compounds [nitrosoalkanes] represented by RN = O generated by oxidation of primary amine (RNH 2 ), primary amine (RNH 2 ) or N-nitroso compounds [N-nitrosamines] represented by RNH-N = O or R 2 NN = O produced by reaction of secondary amine (R 2 NH) with nitrous acid, etc. . R is an N-substituent such as an alkyl group or a hydroxyalkyl group. The nitroso compound represented by RN = O may be mutated to an oxime when R is a primary alkyl group or a secondary alkyl group. In the present invention, these tautomers are also included in the nitroso compound (A). In addition, the nitrosoalkane may be a dimer, and in the present invention, this dimer is also included in the nitroso compound (A). N-nitrosamine represented by RNH-N = O is an unstable substance and decomposes at room temperature to be mutated to diazo hydroxide. In the present invention, this tautomer is also included in the nitroso compound (A).
　ニトロソ化合物(A)の具体例としては、N-ニトロソジエタノールアミン、N-ニトロソヘプタメチレンイミン、N-ニトロソジメチルアミン、N-ニトロソジエチルアミン、N-ニトロソメチルヒドロキシエチルアミン、N-エチル-N-（2-ヒドロキシエチル）ニトロソアミン、N-tert-ブチル-N-エチルニトロソアミン、N-ニトロソジブチルアミン、N-エチル-N-（4-ヒドロキシブチル）ニトロソアミン、N-ブチル-N-（4-ヒドロキシブチル）ニトロソアミン、N-ニトロソモルホリンなどが挙げられる。これらのうち、本発明に係る方法の分解対象として水に溶解又は混和するニトロソ化合物(A)が好適に用いられる。 Specific examples of the nitroso compound (A) include N-nitrosodiethanolamine, N-nitrosoheptamethyleneimine, N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosomethylhydroxyethylamine, N-ethyl-N- (2- Hydroxyethyl) nitrosamine, N-tert-butyl-N-ethylnitrosamine, N-nitrosodibutylamine, N-ethyl-N- (4-hydroxybutyl) nitrosamine, N-butyl-N- (4-hydroxybutyl) nitrosamine, N-nitrosomorpholine etc. are mentioned. Of these, the nitroso compound (A) that is dissolved or mixed in water is preferably used as the decomposition target of the method according to the present invention.
　このようなニトロソ化合物(A)を含む被処理液としては、燃焼排ガス中の二酸化炭素を吸収するために用いられたアミン類水溶液（以下、吸収液ということがある。）が好適に用いられる。該吸収液は、主成分としてのアミン類と、不純物としてのニトロソ化合物(A)とを少なくとも含む水溶液である。 As the liquid to be treated containing such a nitroso compound (A), an aqueous amine solution used for absorbing carbon dioxide in the combustion exhaust gas (hereinafter sometimes referred to as an absorbing liquid) is preferably used. The absorbing liquid is an aqueous solution containing at least amines as main components and a nitroso compound (A) as impurities.
　ニトロソ化合物(A)の沸点はアミン類の沸点よりも高い場合が多いので、被処理液からアミン類を留去してニトロソ化合物(A)を濃縮しておいてから本発明の分解方法を行うことが好ましい。被処理液中のアミン類が少量であれば該アミン類との反応によって消費されるハロゲン化水素酸量が減り、分解のために添加するハロゲン化水素酸の量を減らすことができる。また、ニトロソ化合物(A)を分解させるための加熱によって無用に分解されるアミン類を減らすことができる。また、被処理液中の水の量も減らしておくことが好ましい。後述するように副生するハロゲン化ニトリシルが水と反応して亜硝酸を生成し、この亜硝酸が再びアミン類をニトロソ化させることがあるからである。 Since the boiling point of the nitroso compound (A) is often higher than the boiling point of the amines, the decomposition method of the present invention is performed after concentrating the nitroso compound (A) by distilling off the amines from the liquid to be treated. It is preferable. If the amount of amines in the liquid to be treated is small, the amount of hydrohalic acid consumed by the reaction with the amines is reduced, and the amount of hydrohalic acid added for decomposition can be reduced. In addition, amines that are unnecessarily decomposed by heating to decompose the nitroso compound (A) can be reduced. It is also preferable to reduce the amount of water in the liquid to be treated. This is because, as will be described later, nitrile halide produced as a by-product reacts with water to produce nitrous acid, and this nitrous acid may nitrosate amines again.
　本発明に用いられるハロゲン化水素酸は、特に制限されない。例えば、塩酸、臭化水素酸、およびヨウ化水素酸からなる群より選ばれる少なくとも一つが挙げられる。ハロゲン化水素酸の量は、ハロゲン化水素の量として、アミノ基及びニトロソ基の合計量100モル部に対して、100モル部以上であることが好ましい。ニトロソ基の量には互変異体の量を含む。ハロゲン化水素の量をアミノ基及びニトロソ基の合計量よりも多めにすることによって、ニトロソ化合物(A)から再生するアミン類がハロゲン化水素と反応して熱安定性塩を生成し、ニトロソ化合物(A)から再生したアミン類の無用な熱分解を防止できる。
　また、被処理液のｐHは、5未満であることが好ましく、3未満であることがより好ましく、2未満であることがさらに好ましい。 The hydrohalic acid used in the present invention is not particularly limited. Examples thereof include at least one selected from the group consisting of hydrochloric acid, hydrobromic acid, and hydroiodic acid. The amount of hydrohalic acid is preferably 100 mol parts or more relative to 100 mol parts of the total amount of amino groups and nitroso groups as the amount of hydrogen halide. The amount of nitroso group includes the amount of tautomers. By making the amount of hydrogen halide larger than the total amount of amino groups and nitroso groups, the amines regenerated from the nitroso compound (A) react with the hydrogen halide to form a heat-stable salt, and the nitroso compound Unnecessary thermal decomposition of amines regenerated from (A) can be prevented.
Further, the pH of the liquid to be treated is preferably less than 5, more preferably less than 3, and even more preferably less than 2.
　ニトロソ化合物(A)の分解は、水の沸点以上で且つ該アミン類の沸点以下の温度に加熱することによって行われる。本発明によるニトロソ化合物(A)の分解過程の詳細は定かでないが、例えば、下式に示すような化学反応で分解されていると推測する。この分解によってニトロソ化合物(A)を元のアミン類に再生することができる。 The decomposition of the nitroso compound (A) is performed by heating to a temperature not lower than the boiling point of water and not higher than the boiling point of the amines. The details of the decomposition process of the nitroso compound (A) according to the present invention are not clear, but it is assumed that it is decomposed by a chemical reaction as shown in the following formula, for example. By this decomposition, the nitroso compound (A) can be regenerated to the original amines.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　この分解反応で副生するYNOハロゲン化ニトロシルは、水との反応によって亜硝酸を副生する。水の沸点以上に加熱すると水が気化し、水とハロゲン化ニトリシルとの反応機会が減り亜硝酸の生成を抑制することができる。また、ハロゲン化ニトロシルは、沸点が、例えば塩化ニトロシルは-6.4℃であり、アミン類より低い場合が多いので、ニトロソ化合物(A)を分解させるための加熱温度を調整することによってハロゲン化ニトリシルを気化させて除去することができる。 The YNO nitrosyl halide produced as a by-product in this decomposition reaction produces nitrous acid as a by-product by reaction with water. Heating above the boiling point of water vaporizes the water, reducing the opportunity for reaction between water and nitrile halide and suppressing the production of nitrous acid. In addition, halogenated nitrosyl has a boiling point, for example, nitrosyl chloride is −6.4 ° C., which is often lower than amines. Therefore, by adjusting the heating temperature for decomposing the nitroso compound (A), the nitrosyl halide is reduced. It can be removed by vaporization.
　被処理液に含まれているアミン類のうちハロゲン化水素と反応して熱安定性塩を生成したものは、ニトロソ化合物(A)を分解させるための加熱によっても分解しない。しかし、熱安定性塩化していないアミン類は、ニトロソ化合物(A)を分解させるための加熱によって多少分解するので、加熱温度はできるだけ低い温度で行うことが好ましい。水の気化とアミン類の分解抑制とニトロソ化合物(A)の分解促進とをバランスしやすくするために、大気圧以下の圧力に、好ましくは、水の沸点がアミン類の熱分解を抑制するに十分な温度以下になる圧力に、より好ましくは、アミン類のニトロソ化物を含む被処理液とハロゲン化水素酸との混合物の沸点が１００℃以下になる圧力に、下げて加熱することが好ましい。 Among the amines contained in the liquid to be treated, those which have reacted with hydrogen halide to produce a heat-stable salt are not decomposed even by heating to decompose the nitroso compound (A). However, the heat-stable non-chlorinated amines are somewhat decomposed by heating for decomposing the nitroso compound (A). Therefore, the heating temperature is preferably as low as possible. In order to easily balance the vaporization of water, the decomposition of amines and the promotion of decomposition of the nitroso compound (A), the pressure is set to a pressure below atmospheric pressure, preferably the boiling point of water suppresses the thermal decomposition of amines. It is preferable to heat by lowering the pressure to a sufficient temperature or lower, more preferably to a pressure at which the boiling point of the mixture of the liquid to be treated containing nitrosated amines and hydrohalic acid is 100 ° C. or lower.
　本発明の一実施形態に係る被処理ガス中の二酸化炭素を回収する方法は、二酸化炭素を含む被処理ガスとアミン類を含むCO2リーン吸収液とを接触させて、二酸化炭素をCO2リーン吸収液に吸収させて、CO2リッチ吸収液を得る工程(I)、CO2リッチ吸収液を加熱して二酸化炭素を脱離させてCO2リーン吸収液に再生する工程(II)、再生されたCO2リーン吸収液の一部を、ハロゲン化水素酸の存在下に、水の沸点以上で且つアミン類の沸点以下にて、加熱する工程(III)、および工程(II)で再生されたCO2リーン吸収液の残部および／または工程(III)で加熱されたCO2リーン吸収液を前記二酸化炭素吸収工程(I)に供給する工程(IV)を有する。 A method for recovering carbon dioxide in a gas to be treated according to an embodiment of the present invention comprises contacting a gas to be treated containing carbon dioxide with a CO 2 lean absorbing solution containing amines to convert the carbon dioxide into CO 2 lean. is absorbed in the absorbing liquid, to obtain a CO 2 rich absorbent solution (I), the step of carbon dioxide by heating the CO 2 rich absorbent solution desorbed to play CO 2 lean absorbing solution (II), is reproduced A part of the CO 2 lean absorbing solution was regenerated in steps (III) and (II) in which heating was performed in the presence of hydrohalic acid above the boiling point of water and below the boiling point of amines. A step (IV) of supplying the remainder of the CO 2 lean absorbing solution and / or the CO 2 lean absorbing solution heated in the step (III) to the carbon dioxide absorbing step (I).
　本発明の一実施形態に係る被処理ガス中の二酸化炭素を回収する方法は、例えば、図４に示すような装置にて行うことができる。
　本発明において、工程(I)、工程(II)および工程(IV)は、通常、連続的に且つ同時に行われる。
　工程(I)：被処理ガス11はブロワ12にて吸収塔1の底部3に供給され、充填層2を上昇し、頂部から処理済みガス4として放出される。被処理ガス11はその圧力が常圧以上になっていてもよいし、常圧であってもよい。被処理ガス11の温度は100℃以下が好ましい。充填層2の上部にアミン類を含むCO2リーン吸収液がノズル6から降り注がれ、充填層2にて被処理ガスと接触し、被処理ガス中の二酸化炭素を吸収し、吸収塔底部10に溜まる。底部10に溜まった液は、二酸化炭素を豊富に含み、CO2リッチ吸収液と呼ばれる。 The method for recovering carbon dioxide in the gas to be treated according to an embodiment of the present invention can be performed by, for example, an apparatus as shown in FIG.
In the present invention, step (I), step (II) and step (IV) are usually performed continuously and simultaneously.
Step (I): The gas 11 to be treated is supplied to the bottom 3 of the absorption tower 1 by the blower 12, rises in the packed bed 2, and is discharged as a treated gas 4 from the top. The gas to be treated 11 may have a pressure equal to or higher than normal pressure, or may be normal pressure. The temperature of the gas to be treated 11 is preferably 100 ° C. or lower. A CO 2 lean absorbing liquid containing amines is poured from the nozzle 6 onto the top of the packed bed 2 and comes into contact with the gas to be treated in the packed bed 2 to absorb carbon dioxide in the gas to be treated, and the bottom of the absorption tower Accumulate at 10. The liquid accumulated in the bottom 10 is rich in carbon dioxide and is called a CO 2 rich absorption liquid.
　工程(II)：底部10から抜き出されたCO2リッチ吸収液は熱交換器22にて加熱されて再生塔（脱離塔）13の充填層15の上部にノズル14から降り注がれる。注がれた液は充填層15を下降し、脱離塔の底部に溜まる。脱離塔の底部に溜まる液は、後述するように、二酸化炭素の含有量が少なく、CO2リーン吸収液と呼ばれる。塔底にはリボイラ23が設置されている。リボイラで気化された蒸気が充填層2を上昇し、充填層2を下降するCO2リッチ吸収液を加熱して二酸化炭素を脱離させる。脱離した二酸化炭素は、水洗部26にてミスト除去され、脱離塔の頂部から排出される。さらに分離器17にて水が回収され、二酸化炭素は管18にて次工程に送られ、回収した水は脱離塔の水洗部26または吸収塔の頂部のノズル9に供給される。 Step (II): The CO 2 rich absorbent extracted from the bottom 10 is heated by the heat exchanger 22 and poured from the nozzle 14 onto the top of the packed bed 15 of the regeneration tower (desorption tower) 13. The poured liquid descends through the packed bed 15 and accumulates at the bottom of the desorption tower. As will be described later, the liquid accumulated at the bottom of the desorption tower has a low carbon dioxide content and is called a CO 2 lean absorbing liquid. A reboiler 23 is installed at the bottom of the tower. Steam vaporized by the reboiler ascends the packed bed 2 and heats the CO 2 rich absorbent that descends the packed bed 2 to desorb carbon dioxide. The desorbed carbon dioxide is removed by mist in the water washing section 26 and discharged from the top of the desorption tower. Further, water is recovered by the separator 17, carbon dioxide is sent to the next step through the pipe 18, and the recovered water is supplied to the water washing section 26 of the desorption tower or the nozzle 9 at the top of the absorption tower.
　工程(IV)：脱離塔の底部に溜まったCO2リーン吸収液は熱交換器22にて冷却されて、吸収塔1に戻される。 Step (IV): The CO 2 lean absorbent stored at the bottom of the desorption tower is cooled by the heat exchanger 22 and returned to the absorption tower 1.
　本発明において、工程(III)は、連続的に常時行ってもよいが、吸収液のCO2吸収能が低下してきた場合に一時的に行うことが、省エネルギの観点から好ましい。吸収液のCO2吸収能の低下は、既に述べたとおり、吸収液中の熱安定性塩および／またはニトロソ化合物(A)の量の増加によって引き起こされる。吸収液中の熱安定性塩およびニトロソ化合物(A)の量は公知の方法で測定することができる。 In the present invention, the step (III) may be performed continuously continuously, but it is preferable from the viewpoint of energy saving that the step (III) is performed temporarily when the CO 2 absorption capacity of the absorbing solution is lowered. The decrease in the CO 2 absorption capacity of the absorbing solution is caused by an increase in the amount of heat-stable salt and / or nitroso compound (A) in the absorbing solution, as already described. The amount of the heat stable salt and the nitroso compound (A) in the absorbing solution can be measured by a known method.
　工程(III)：バルブ30を開くとリクレーミング装置24の伝熱管に水蒸気が送られる。脱離塔13の底部から抜き出されたCO2リーン吸収液がリクレーミング装置24の伝熱管にて加熱される。そして、CO2リーン吸収液に含まれるアミン類および水は気化し脱離塔に戻される。熱安定性塩およびニトロソ化合物(A）は濃縮される。濃縮された液にハロゲン化水素酸を供給して、濃縮液をハロゲン化水素酸の存在下に加熱する。このようにすると、ニトロソ化合物(A)がニトロソ化前のアミン類に再生される。なお、加熱温度は水の沸点以上で且つ該アミン類の沸点以下の温度である。加熱時の圧力は大気圧以下であることが好ましい。再生されたアミン類は気化して脱離塔に戻る。戻り切れなかったアミン類はハロゲン化水素酸と反応して熱安定性塩になる。
　工程(V)：工程(III)で加熱されたCO2リーン吸収液に熱安定性塩が残っている場合はスラッジとしてリクレーミング装置24から取り出すか、またはアルカリ成分（例えば、アルカリ金属水酸化物、アルカリ金属炭酸塩など）を添加し加熱して熱安定性塩をアミン類に再生する。再生されたアミン類は気化させて脱離塔に戻すことができる。 Step (III): When the valve 30 is opened, water vapor is sent to the heat transfer tube of the reclaiming device 24. The CO 2 lean absorbent extracted from the bottom of the desorption tower 13 is heated by the heat transfer tube of the reclaiming device 24. The amines and water contained in the CO 2 lean absorbent are vaporized and returned to the desorption tower. The heat stable salt and nitroso compound (A) are concentrated. Hydrohalic acid is supplied to the concentrated liquid, and the concentrated liquid is heated in the presence of hydrohalic acid. In this way, the nitroso compound (A) is regenerated into amines before nitrosation. The heating temperature is not lower than the boiling point of water and not higher than the boiling point of the amines. The pressure during heating is preferably not more than atmospheric pressure. The regenerated amines are vaporized and returned to the desorption tower. The amines that cannot be returned react with hydrohalic acid to form heat stable salts.
Step (V): If the heat-stable salt remains in the CO 2 lean absorbent heated in step (III), remove it from the reclaiming device 24 as sludge, or use an alkali component (for example, alkali metal hydroxide, Heat-stable salt is regenerated to amines by adding and heating an alkali metal carbonate. The regenerated amines can be vaporized and returned to the desorption tower.
　以下に実施例を示して本発明をより具体的に説明する。なお、本発明はこれら実施例によって限定されるものではない。 Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited by these Examples.
　実施例で使用した装置は一例であり、実施範囲を制限するものではない。例えば、液の加熱用のマントルヒータやリボンヒータ、容器としての丸底フラスコ、冷却管としてのリービッヒ管等、他の機器を使用しても同様の結果を得ることができる。 The equipment used in the examples is an example, and does not limit the scope of implementation. For example, similar results can be obtained by using other equipment such as a mantle heater or a ribbon heater for heating the liquid, a round bottom flask as a container, and a Liebig tube as a cooling pipe.
　ニトロソ化合物の量は、ＧＣ（ガスクロマトグラフ）－ＴＥＡ（熱エネルギ分析）装置（Ｅｌｌｕｔｉａ製　ＴＥＡ－８００）で測定した。
　アミン化合物の量はイオンクロマトグラフ（ＤＩＯＮＥＸ製 ＩＣＳ－１５００）で測定した。なお、アミン化合物の量は塩化アミンをアミン化合物に重量換算した量を含む。 The amount of the nitroso compound was measured with a GC (gas chromatograph) -TEA (thermal energy analysis) apparatus (TEA-800 manufactured by Ellutia).
The amount of the amine compound was measured by an ion chromatograph (ICS-1500, manufactured by DIONEX). The amount of the amine compound includes an amount obtained by converting amine chloride into an amine compound by weight.
実施例１
　図１に示す装置を用いて実施した。
　ジエタノールアミン（C4H11NO2、DEA、分子量105g/mol、沸点268.8℃（昭和化学のＭＳＤＳによる））8.5質量部（80.95モル部）、水分1.499質量部、およびニトロソジエタノールアミン（C4H10N2O3、NDEA、分子量134g/mol）0.001質量部(0.007モル部)の混合液を用意した。 Example 1
It implemented using the apparatus shown in FIG.
Diethanolamine (C 4 H 11 NO 2 , DEA, molecular weight 105 g / mol, boiling point 268.8 ° C (according to Showa Chemical MSDS)) 8.5 parts by mass (80.95 parts by mole), moisture 1.499 parts by weight, and nitrosodiethanolamine (C 4 H 10 N A mixed solution of 0.001 part by mass (0.007 mol part) of 2 O 3 , NDEA, molecular weight 134 g / mol) was prepared.
　フラスコ103に前記混合液を入れ、これに塩酸（塩化水素濃度36質量%）8.62質量部(85.11モル部)を添加した。調製液のpHは1未満であった。
　温度140℃に調整されたシリコーンオイル102を溜めたオイルバス101にフラスコ103を浸けて調製液を30分間加熱した。フラスコ103は連結管107を経由して冷却管105に接続されている。フラスコ103の上部及び連結管107はヒータ106で結露しないように加熱されている。フラスコ103で蒸発した気体は20℃の冷却水108が循環する冷却管105で凝縮させ該凝縮液109を回収瓶（図示せず）で回収した。 To the flask 103, the mixed solution was added, and hydrochloric acid (hydrogen chloride concentration 36% by mass) 8.62 parts by mass (85.11 mol parts) was added thereto. The pH of the preparation was less than 1.
The flask 103 was immersed in an oil bath 101 in which silicone oil 102 adjusted to a temperature of 140 ° C. was stored, and the prepared solution was heated for 30 minutes. The flask 103 is connected to the cooling pipe 105 via a connecting pipe 107. The upper part of the flask 103 and the connecting pipe 107 are heated by the heater 106 so as not to condense. The gas evaporated in the flask 103 was condensed in a cooling pipe 105 in which 20 ° C. cooling water 108 circulated, and the condensate 109 was collected in a collection bottle (not shown).
　凝縮液109に含まれるニトロソ化合物の量およびフラスコ103に残った液に含まれるニトロソ化合物の量を測定しその合計を算出した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。
　また、凝縮液109に含まれるアミン化合物の量およびフラスコ103に残った液に含まれるアミン化合物の量を測定しその合計を算出した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量からの変化は無かった。すなわち、アミン化合物は分解しなかった。 The amount of the nitroso compound contained in the condensate 109 and the amount of the nitroso compound contained in the liquid remaining in the flask 103 were measured, and the total was calculated. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
Further, the amount of amine compound contained in the condensate 109 and the amount of amine compound contained in the liquid remaining in the flask 103 were measured, and the total was calculated. The total amount of the amine compound did not change from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
比較例１
　塩酸の代わりに水8.62質量部を添加した以外は実施例１と同じ方法で実施した。アミン化合物およびニトロソ化合物の合計量は、いずれも、調製液に含まれていたアミン化合物の量およびニトロソ化合物の量から変化が無かった。ニトロソ化合物は全く分解しなかった。 Comparative Example 1
The same procedure as in Example 1 was performed except that 8.62 parts by mass of water was added instead of hydrochloric acid. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
比較例２
　図２に示す装置(オイルバス101による加熱の代わりにマントルヒータ206にて280℃で加熱）を用いた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。また、アミン化合物の合計量は７割程度まで減少していた。すなわち、ニトロソ化合物は完全に分解したが、ニトロソ化合物の分解と同時にCO2吸収に有用なアミン化合物も分解した。 Comparative Example 2
The same procedure as in Example 1 was performed except that the apparatus shown in FIG. 2 (heating at 280 ° C. with a mantle heater 206 instead of heating with the oil bath 101) was used. The total amount of nitroso compounds was below the detection limit. Moreover, the total amount of amine compounds was reduced to about 70%. That is, although the nitroso compound was completely decomposed, the amine compound useful for CO 2 absorption was also decomposed simultaneously with the decomposition of the nitroso compound.
実施例２
　シリコーンオイル102の温度を110℃に変え、加熱時間を１時間に変えた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量はほぼ検出限界以下であった。すなわち、ニトロソ化合物はほぼ完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 2
The same procedure as in Example 1 was performed except that the temperature of the silicone oil 102 was changed to 110 ° C. and the heating time was changed to 1 hour. The total amount of nitroso compounds was almost below the detection limit. That is, the nitroso compound was almost completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
比較例３
　シリコーンオイル102の温度を90℃に変え、加熱時間を１時間に変えた以外は実施例１と同じ方法で実施した。アミン化合物およびニトロソ化合物の合計量は、いずれも、調製液に含まれていたアミン化合物の量およびニトロソ化合物の量から変化が無かった。ニトロソ化合物は全く分解しなかった。 Comparative Example 3
The same procedure as in Example 1 was performed except that the temperature of the silicone oil 102 was changed to 90 ° C. and the heating time was changed to 1 hour. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
比較例４
　塩酸の代わりに水8.62質量部を添加した以外は実施例２と同じ方法で実施した。アミン化合物およびニトロソ化合物の合計量は、いずれも、調製液に含まれていたアミン化合物の量およびニトロソ化合物の量から変化が無かった。ニトロソ化合物は全く分解しなかった。 Comparative Example 4
The same procedure as in Example 2 was performed except that 8.62 parts by mass of water was added instead of hydrochloric acid. The total amount of the amine compound and the nitroso compound was not changed from the amount of the amine compound and the amount of the nitroso compound contained in the preparation solution. The nitroso compound did not decompose at all.
実施例３
　塩酸の代わりに臭化水素酸（臭化水素濃度48質量%）14.2質量部(84.24モル部)を添加した以外は実施例２と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 3
It implemented by the same method as Example 2 except having added 14.2 mass parts (84.24 mol parts) of hydrobromic acid (hydrogen bromide concentration 48 mass%) instead of hydrochloric acid. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
実施例４
　塩酸の代わりにヨウ化水素酸（用化水素濃度57質量%）19.1質量部(85.11モル部)を添加した以外は実施例２と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 4
It implemented by the same method as Example 2 except having added 19.1 mass parts (85.11 mol parts) of hydroiodic acid (concentration of hydrogen iodide 57 mass%) instead of hydrochloric acid. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
実施例５
　ジエタノールアミンの代わりにN-ジn-ブチルアミンを用い、ニトロソジエタノールアミンの代わりにN-ニトロソジn-ブチルアミン（沸点237℃）を用いた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 5
The same procedure as in Example 1 was carried out except that N-din-butylamine was used instead of diethanolamine and N-nitrosodin-butylamine (boiling point 237 ° C.) was used instead of nitrosodiethanolamine. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
実施例６
　ジエタノールアミンの代わりにN-エチルアミノエタノールを用い、ニトロソジエタノールアミンの代わりにN-エチル-N-(2-ヒドロキシエチル)ニトロソアミン（103℃の蒸気圧3mmHg）を用い、シリコーンオイル102の温度を103℃に変えた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 6
Use N-ethylaminoethanol instead of diethanolamine, and N-ethyl-N- (2-hydroxyethyl) nitrosamine (vapor pressure of 3 mmHg at 103 ° C) instead of nitrosodiethanolamine, and the temperature of silicone oil 102 to 103 ° C The same method as in Example 1 was carried out except that the change was made. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
実施例７
　ピペラジン（２価のアミン化合物、分子量86g/mol）1.0質量部(11.63モル部)、　水8.999質量部、および1-ニトロソピペラジン（分子量115g/mol、沸点265℃）0.001質量部(0.009モル部)の混合液を用意した。
　実施例１で用いた混合液を前記混合液に変え、塩酸（塩化水素濃度36質量%）の量を2.53質量部(25.0モル部)に変えた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。 Example 7
Piperazine (divalent amine compound, molecular weight 86 g / mol) 1.0 part by mass (11.63 mol part), water 8.999 parts by mass, and 1-nitrosopiperazine (molecular weight 115 g / mol, boiling point 265 ° C.) 0.001 part by mass (0.009 mol part) A mixed solution was prepared.
The same procedure as in Example 1 was performed except that the mixed solution used in Example 1 was changed to the above mixed solution, and the amount of hydrochloric acid (hydrogen chloride concentration: 36 mass%) was changed to 2.53 parts by mass (25.0 mol parts). The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose.
実施例８
　冷却器105に接続された回収瓶をアスピレータ（Yamato WP-15）に繋ぎ連続的に排気してフラスコ103内の圧力を絶対圧力50ｋPaに変え、冷却水の温度を4℃に変えた以外は比較例３と同じ方法で実施した。この際、水の沸点は約８２℃であった。ニトロソ化合物の合計量はほぼ検出限界以下であった。すなわち、ニトロソ化合物はほぼ完全に分解した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。大気圧下でニトロソ化合物の分解が進行しない低温（比較例３参照）であっても、圧力を大気圧以下に下げることによってニトロソ化合物の分解が促進されることが確認された。 Example 8
Compared except that the recovery bottle connected to the cooler 105 is connected to an aspirator (Yamato WP-15) and continuously evacuated to change the pressure in the flask 103 to 50 kPa absolute and the temperature of the cooling water to 4 ° C. Performed in the same manner as Example 3. At this time, the boiling point of water was about 82 ° C. The total amount of nitroso compounds was almost below the detection limit. That is, the nitroso compound was almost completely decomposed. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose. It was confirmed that the decomposition of the nitroso compound was promoted by lowering the pressure to the atmospheric pressure or lower even at a low temperature at which the decomposition of the nitroso compound did not proceed under atmospheric pressure (see Comparative Example 3).
実施例９
　水9.999質量部、およびニトロソジエタノールアミン0.001質量部(0.007モル部)の混合液を用意した。
　実施例１で用いた混合液を前記混合液に変え、塩酸（塩化水素濃度36質量%）の量を0.0112質量部(0.11モル部)に変えた以外は実施例１と同じ方法で実施した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。一方、調製液に含まれてなかったアミン化合物が検出された。ニトロソ化合物の分解によってアミン化合物を生成したことが確認できた。 Example 9
A mixed liquid of 9.999 parts by mass of water and 0.001 parts by mass (0.007 mol parts) of nitrosodiethanolamine was prepared.
The same procedure as in Example 1 was performed except that the mixed solution used in Example 1 was changed to the above mixed solution, and the amount of hydrochloric acid (hydrogen chloride concentration: 36% by mass) was changed to 0.0112 parts by mass (0.11 mol part). The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed. On the other hand, an amine compound that was not contained in the preparation solution was detected. It was confirmed that the amine compound was produced by decomposition of the nitroso compound.
実施例１０
　図３に示すリクレーミング装置を用いて実施した。
　実施例１で用意した調製液と同じ組成の液13を供給口311からリクレーミング容器308に入れ、伝熱管309に140℃の水蒸気301を供給することにより液13を加熱した。加熱中は排気口312からのガスを20℃に冷却して凝縮液を回収した。リクレーミング後にリクレーミング容器308内に残った液を抜出口310から抜き出した。
　凝縮液に含まれるニトロソ化合物の量および抜出口310から抜き出した液に含まれるニトロソ化合物の量を測定しその合計を算出した。ニトロソ化合物の合計量は検出限界以下であった。すなわち、ニトロソ化合物は完全に分解した。
　また、凝縮液に含まれるアミン化合物の量および抜出口310から抜き出した液に含まれるアミン化合物の量を測定しその合計を算出した。アミン化合物の合計量は調製液に含まれていたアミン化合物の量から変化が無かった。すなわち、アミン化合物は分解しなかった。リクレーミング装置によってニトロソ化合物の分解ができることを確認できた。 Example 10
The reclaiming apparatus shown in FIG. 3 was used.
The liquid 13 having the same composition as the prepared liquid prepared in Example 1 was put into the reclaiming container 308 through the supply port 311, and the liquid 13 was heated by supplying steam 301 at 140 ° C. to the heat transfer tube 309. During heating, the gas from the exhaust port 312 was cooled to 20 ° C. to recover the condensate. The liquid remaining in the reclaiming container 308 after reclaiming was extracted from the outlet 310.
The amount of the nitroso compound contained in the condensate and the amount of the nitroso compound contained in the solution extracted from the outlet 310 were measured and the total was calculated. The total amount of nitroso compounds was below the detection limit. That is, the nitroso compound was completely decomposed.
Further, the amount of the amine compound contained in the condensed liquid and the amount of the amine compound contained in the liquid extracted from the outlet 310 were measured and the total was calculated. The total amount of the amine compound was not changed from the amount of the amine compound contained in the preparation solution. That is, the amine compound did not decompose. It was confirmed that the nitroso compound could be decomposed by the reclaiming device.
　101　オイルバス、　102　シリコーンオイル、　103　フラスコ、　105　冷却管、　106　ヒータ、107　連結管、　108　冷却水、109　凝縮液、　206　マントルヒータ、　308　リクレーミング容器、　309　伝熱管、　301　水蒸気、　302　ドレイン、　310　液抜出口、　311　液供給口、　312　排気口 101 oil bath, 102 silicone oil, 103 flask, 105 cooling tube, 106 heater, 107 connecting tube, 108 cooling water, 109 condensate, 206 mantle heater, 308 reclaiming vessel, 309 heat transfer tube, 301 water vapor, 302 drain, 310 liquid Outlet, 311 liquid supply port, 312 exhaust port

Claims (12)

  1. 　アミン類のニトロソ化物を含む被処理液を、ハロゲン化水素酸の存在下に、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む、
    アミン類のニトロソ化物の分解方法。     Heating a liquid containing a nitrosated product of amines in the presence of hydrohalic acid at a temperature not lower than the boiling point of water and not higher than the boiling point of the amines.
    A method for decomposing amine nitrosates.
  2. 　被処理液はアミン類をさらに含む、請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing a nitrosated product of an amine according to claim 1, wherein the liquid to be treated further contains an amine.
  3. 　ハロゲン化水素の量が、アミノ基及びニトロソ基の合計量100モル部に対して、100モル部以上である、請求項２に記載のアミン類のニトロソ化物の分解方法 The method for decomposing an amine nitrosate according to claim 2, wherein the amount of hydrogen halide is 100 mol parts or more with respect to 100 mol parts of the total amount of amino groups and nitroso groups.
  4. 　被処理液が、燃焼排ガス中の二酸化炭素を吸収するために用いられたアミン類水溶液である、請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing amine nitrosates according to claim 1, wherein the liquid to be treated is an aqueous amine solution used to absorb carbon dioxide in combustion exhaust gas.
  5. 　ハロゲン化水素酸が、塩酸、臭化水素酸、およびヨウ化水素酸からなる群より選ばれる少なくとも一つである、請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing amine nitrosates according to claim 1, wherein the hydrohalic acid is at least one selected from the group consisting of hydrochloric acid, hydrobromic acid, and hydroiodic acid.
  6. 　前記加熱を、大気圧以下の圧力下にて行う、請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing a nitrosated product of an amine according to claim 1, wherein the heating is performed under a pressure equal to or lower than atmospheric pressure.
  7. 　前記加熱を、アミン類のニトロソ化物を含む被処理液とハロゲン化水素酸の混合物の沸点が１００℃以下になる圧力にて行う、請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing amine nitrosates according to claim 1, wherein the heating is performed at a pressure at which the boiling point of the mixture of the liquid to be treated containing the nitrosates of amines and hydrohalic acid is 100 ° C or lower.
  8. 　アミン類がアルカノールアミン類である請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing a nitrosated product of an amine according to claim 1, wherein the amine is an alkanolamine.
  9. 　ハロゲン化水素酸の存在下での加熱の後、アルカリ成分の存在下で加熱することをさらに含む請求項１に記載のアミン類のニトロソ化物の分解方法。 The method for decomposing amine nitrosates according to claim 1, further comprising heating in the presence of an alkali component after heating in the presence of hydrohalic acid.
  10. 　アミン類のニトロソ化物を含む被処理液を、ｐＨ３未満にして、水の沸点以上で且つ該アミン類の沸点以下の温度にて、加熱することを含む、
    アミン類のニトロソ化物の分解方法。     Heating the liquid to be treated containing a nitrosated product of amines to a pH of less than 3 at a temperature not lower than the boiling point of water and not higher than the boiling point of the amines.
    A method for decomposing amine nitrosates.
  11. 　二酸化炭素を含む被処理ガスとアミン類を含むCO2リーン吸収液とを接触させて、二酸化炭素をCO2リーン吸収液に吸収させて、CO2リッチ吸収液を得る工程(I)、
    　CO2リッチ吸収液を加熱して二酸化炭素を脱離させてCO2リーン吸収液に再生する工程(II)、
    　再生されたCO2リーン吸収液の一部を、ハロゲン化水素酸の存在下に、水の沸点以上で且つアミン類の沸点以下の温度にて、加熱する工程（III)、および
    　工程（II)で再生されたCO2リーン吸収液の残部および／または工程(III)で加熱されたCO2リーン吸収液を前記二酸化炭素吸収工程(I)に供給する工程(IV)、
    　を有する被処理ガス中の二酸化炭素を回収する方法。     A step (I) of obtaining a CO 2 rich absorbent by contacting a gas to be treated containing carbon dioxide with a CO 2 lean absorbent containing amines to absorb carbon dioxide in the CO 2 lean absorbent;
    A step of heating the CO 2 rich absorbent to desorb carbon dioxide and regenerating it into a CO 2 lean absorbent (II),
    Step (III) and (II) of heating a part of the regenerated CO 2 lean absorbent at a temperature not lower than the boiling point of water and not higher than the boiling point of amines in the presence of hydrohalic acid. A step (IV) of supplying the remainder of the CO 2 lean absorbent regenerated in step 1 and / or the CO 2 lean absorbent heated in step (III) to the carbon dioxide absorption step (I),
    A method for recovering carbon dioxide in a gas to be treated.
  12. 　工程(III)で加熱されたCO2リーン吸収液をアルカリ成分の存在下で加熱する工程(V)をさらに有する請求項１１に記載の被処理ガス中の二酸化炭素を回収する方法。 The method for recovering carbon dioxide in the gas to be treated according to claim 11, further comprising a step (V) of heating the CO 2 lean absorbent heated in the step (III) in the presence of an alkali component.
PCT/JP2014/068109 2013-07-08 2014-07-08 Method for decomposing nitrosated amine, and method for recovering carbon dioxide from gas to be treated WO2015005302A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-142931 2013-07-08
JP2013142931A JP6151993B2 (en) 2013-07-08 2013-07-08 Method for decomposing amine nitrosates and method for recovering carbon dioxide in gas to be treated

Publications (1)

Publication Number Publication Date
WO2015005302A1 true WO2015005302A1 (en) 2015-01-15

Family

ID=52279982

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/068109 WO2015005302A1 (en) 2013-07-08 2014-07-08 Method for decomposing nitrosated amine, and method for recovering carbon dioxide from gas to be treated

Country Status (2)

Country Link
JP (1) JP6151993B2 (en)
WO (1) WO2015005302A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6442533B2 (en) * 2015-01-07 2018-12-19 三菱日立パワーシステムズ株式会社 Nitroso compound processing method and processing apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0889756A (en) * 1994-09-28 1996-04-09 Tokyo Electric Power Co Inc:The Treatment of carbon dioxide in gas to be treated and liquid absorbent
JP2006527153A (en) * 2003-06-12 2006-11-30 カンソルブ・テクノロジーズ・インコーポレーテツド Method for recovering CO2 from a gas stream
JP2011115724A (en) * 2009-12-03 2011-06-16 Mitsubishi Heavy Ind Ltd Co2 recovery apparatus and method
JP2012520167A (en) * 2009-03-13 2012-09-06 エイカー クリーン カーボン エーエス Method and plant for amine emissions control

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2758151A2 (en) * 2011-09-23 2014-07-30 Dow Global Technologies LLC Reducing nitrosamine content of amine compositions
CN102701989B (en) * 2012-05-24 2013-11-13 山东华阳农药化工集团有限公司 Method for removing nitrosamine from dinitroaniline herbicides

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0889756A (en) * 1994-09-28 1996-04-09 Tokyo Electric Power Co Inc:The Treatment of carbon dioxide in gas to be treated and liquid absorbent
JP2006527153A (en) * 2003-06-12 2006-11-30 カンソルブ・テクノロジーズ・インコーポレーテツド Method for recovering CO2 from a gas stream
JP2012520167A (en) * 2009-03-13 2012-09-06 エイカー クリーン カーボン エーエス Method and plant for amine emissions control
JP2011115724A (en) * 2009-12-03 2011-06-16 Mitsubishi Heavy Ind Ltd Co2 recovery apparatus and method

Also Published As

Publication number Publication date
JP6151993B2 (en) 2017-06-21
JP2015016391A (en) 2015-01-29

Similar Documents

Publication Publication Date Title
EP2621608B1 (en) Co2 scrubbing process with an alkanolamine
JP4878375B2 (en) Carbon dioxide recovery method
JP5659128B2 (en) Acid gas absorbent, acid gas removal method, and acid gas removal apparatus
JP4634384B2 (en) Absorption liquid, CO2 and / or H2S removal method and apparatus
CN109529541B (en) Carbon dioxide absorbent and carbon dioxide separation and recovery device
WO2007075400A2 (en) Reclaiming amines in carbon dioxide recovery
JP7048352B2 (en) Carbon dioxide absorber and carbon dioxide separation and recovery device
JP2012533414A (en) Carbon dioxide and hydrogen sulfide absorber and process of using the same
WO2009110586A1 (en) Aqueous solution and method for absorbing and collecting carbon dioxide in gas efficiently
JP2018122278A (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal device
JP2017035669A (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal device
JP6479543B2 (en) Acid gas absorbent, acid gas removal method, and acid gas removal apparatus
KR20130010253A (en) Method of resource reuse of stripping system for acid gas capture
JP5812847B2 (en) Carbon dioxide recovery apparatus and method
JP6878261B2 (en) Formic acid recovery agent, formic acid removal method, formic acid removal device, carbon dioxide separation and recovery method and carbon dioxide separation and recovery device
JP2015112574A (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal device
US11135544B2 (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal apparatus
JP2020044489A (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal device
JP6151993B2 (en) Method for decomposing amine nitrosates and method for recovering carbon dioxide in gas to be treated
JP6445874B2 (en) Acid gas absorbent, acid gas removal method, and acid gas removal apparatus
JP6442533B2 (en) Nitroso compound processing method and processing apparatus
US10835858B2 (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal apparatus
AU2019201807B2 (en) Acidic gas absorbent, acidic gas removal method and acidic gas removal apparatus
JP7441123B2 (en) Acid gas removal device and acid gas removal method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14823445

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14823445

Country of ref document: EP

Kind code of ref document: A1