CN107158895B

CN107158895B - Carbon dioxide absorbent

Info

Publication number: CN107158895B
Application number: CN201710572449.9A
Authority: CN
Inventors: 斯养武
Original assignee: Individual
Current assignee: Liu Shengming
Priority date: 2017-07-13
Filing date: 2017-07-13
Publication date: 2020-07-28
Anticipated expiration: 2037-07-13
Also published as: CN107158895A

Abstract

The invention provides a carbon dioxide absorbent, which consists of an alcohol amine main absorbent, piperazine serving as an absorption auxiliary agent, an organic auxiliary agent, activated carbon, a carbon nano tube and deionized water, wherein the organic auxiliary agent is a mixture of dimethyl sulfoxide (DMSO) and Dimethylformamide (DMF); the dosage ratio is as follows: 30-50 parts of main alcohol amine absorbent and piperazine, 10-15 parts of organic auxiliary agent, 50-70 parts of deionized water and 3-8 parts of activated carbon and carbon nano tube. The carbon dioxide absorbent has good absorption rate, absorption capacity and regeneration rate, particularly good stability, and is suitable for various scene applications.

Description

Carbon dioxide absorbent

Technical Field

For absorbing dioxygenCarbon conversion of CO₂And related methods.

Background

Carbon dioxide emissions from industrial sources to the atmosphere are the main cause of the greenhouse effect. In the prior art, particular attention has been paid to the absorption removal of carbon dioxide from flue gas streams. For example, aqueous solutions of hindered amines of aqueous monoethanolamine MEA or methyldiethanolamine MDEA and 2-amino-2-methyl-1-propanol AMP are used as solvents for absorption/scrubbing type regeneration processes for carbon dioxide absorption from coal-fired power plants and gas turbines.

CN1127156A of Kansai electric power Co Ltd and Mitsubishi heavy industry Co Ltd discloses a method for removing carbon dioxide in a gas by using a catalyst containing a compound represented by the general formula R¹NHC(CH₃)₂CH₂OH，R¹An aqueous solution of an amine compound represented by C1-4 alkyl or an aqueous solution containing an amine compound represented by the general formula R²CHR³NHCH₂CH₂OH，R²Is H or C1-4 alkyl, R³An aqueous solution of a compound represented by H or methyl and a piperazine compound selected from piperazine, 2-methylpiperazine, 2, 3-dimethylpiperazine and 2, 5-dimethylpiperazine, or an aqueous solution of a mixed amine solution having a concentration of each of secondary and tertiary amines in the range of 10 to 45% by weight, or an aqueous solution of a piperazine derivative, for example, by contacting with combustion exhaust gas at atmospheric pressure to remove CO in the combustion exhaust gas₂. Treatment of atmospheric combustion exhaust gas to increase CO levels over previously used amine absorption solutions₂The absorption capacity of (1).

CN1608712A of China eastern science and technology university discloses an improved N-methyldiethanolamine decarburization solution, which consists of an N-methyldiethanolamine aqueous solution and an activating agent, wherein the weight ratio of the activating agent to the N-methyldiethanolamine is 0.05-0.20, and the improved N-methyldiethanolamine decarburization solution is characterized in that the activating agent consists of morpholine and piperazine or diethanolamine. The decarbonization solution can be used for removing carbon dioxide in mixed gas such as synthesis gas, city gas or natural gas and the like, and can also be used for removing sulfides. The decarbonizing liquid has the advantages of large absorption capacity, high purification degree, low regeneration energy consumption and the like.

Chengdu Huaxi chemical research place CN1887407A disclosesRemoving CO from mixed gas₂The solvent of (2) is to add a diazacyclo compound and an organic amine with steric hindrance effect as an activating agent into an N-Methyldiethanolamine (MDEA) solution to remove carbon dioxide from a mixed gas. Diazacyclo compounds include piperazine, imidazole, 2-methylimidazole, 2, 5-dimethylimidazole, 4-methylimidazole, and the like, and sterically hindered amines include: tert-butylamine ethyl alcohol (TBE), tert-butylamine ethoxyethyl alcohol (TBEE), 1,2- (di-tert-butylamine ethoxy) ethane (BIS-TB), 2-Piperidineethanol (PE), 1, 8-p-menthane diamine (MPA), 2-amino-2-methyl-1-propanol (AMP), and the like. The solution formula is adopted to purify CO in gas₂The content can be reduced to a very low level, which is obviously reduced compared with the conventional MDEA decarburization method.

Shell in CN101970081A discloses a method for removing CO from a gas₂The method of (2), the method comprising the steps of: (a) obtaining CO enrichment by contacting the gas with an absorption liquid in an absorber₂And purifying the gas to remove CO from the gas₂(ii) a (b) Heating rich in CO₂The absorbing liquid of (4); (c) make the heated CO rich₂Is contacted with a stripping gas in a regenerator at an elevated temperature to obtain a regenerated absorption liquid and a rich CO₂The hot gas stream of (a); wherein at least part is enriched in CO₂Through the absorption liquid rich in CO₂The hot air flow is heated by external heat exchange. The method enables simple and more energy-efficient removal of CO using an absorption liquid₂Because of the use for warming CO-rich₂By partial heat demand of the absorption liquid from the rich CO₂Is provided by the hot gas flow of (a). By making the CO rich₂At least partially condensing the steam in the hot gas stream to transfer the heat demand. The process results in an increase in the overall energy efficiency of 5-25%, preferably 10-25%.

CN103596662A of asahi chemical company discloses a carbon dioxide absorbent and a method for separating and recovering carbon dioxide using the same, which comprises an amine compound, a weak acid compound and water, wherein the amine compound has a pKb of 4.0 to 7.0 in an aqueous solution at 30 ℃, the weak acid compound is boric acid or a boric acid ester having a pKa of 7.0 to 10.0 in an aqueous solution at 30 ℃, and the amount of the weak acid compound is in the range of 0.01 to 1.50 equivalents relative to the amino group of the amine compound; the amine compound includes an amine compound represented by the following general formula (I):

wherein R1 and R2 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

The enfriedel systems company, CN103648612A, discloses a sorbent for the reduction of carbon dioxide from indoor air comprising a solid support; and an amine-based compound carried by the carrier, wherein the amine-based compound is configured to capture at least some of the CO in the room air of the enclosed space₂And releasing at least a portion of the captured CO by flowing outdoor air through the sorbent₂. The carrier is selected from: gels, molecular sieves, nanotube-containing materials, porous materials, sponges and sponge-like materials, electromagnetically charged objects, porous organic polymers, ion exchange resins, polymeric absorbent resins, acrylate polymers, polystyrene divinyl benzene, polymethyl methacrylate (PMMA), polystyrene, Styrene Divinyl Benzene (SDB), fly ash, activated carbon, carbon nanotubes, alumina nanoparticles, synthetic zeolites, porous alumina, porous minerals, porous silica, silica nanoparticles, fumed silica, activated carbon, aluminum phyllosilicates, bentonite, ball clay, fuller's earth, montmorillonite, attapulgite, hectorite, palygorskite, saponite, sepiolite metal, organic frameworks, and one or more combinations thereof. The amine-based compound is selected from: monoethanolamine (MEA), ethanolamine, methylamine, Polyethyleneimine (PEI), Diethanolamine (DEA), dimethylamine, diethylamine, Diisopropanolamine (DIPA), Tetraethylenepentamine (TEPA), Methyldiethanolamine (MDEA), methylethanolamine, and one or more combinations thereof. Can be used for reducing CO from gas₂Comprising a solid support formed from a plurality of particles, wherein the particles are formed substantially in the range of 0.1-10 mmDiameter. The support may be impregnated with an amine-based compound comprising at least 25% secondary amines and is operable for capturing CO₂For the purpose of self-contained 100-2000ppm CO₂CO reduction of concentrated gases₂。

The general electric company, CN103764258A, discloses a composition for absorbing carbon dioxide and related method and system, wherein the carbon dioxide absorbent comprises a) a liquid non-aqueous silicon-based material consisting of a polymer with CO₂Reversibly reacting and/or having a reaction towards CO₂High affinity functionalization of one or more groups; and b) at least one amino alcohol compound. The aminoalcohol compound is selected from the group consisting of diethanolamine, triethanolamine, tripropanolamine, dimethylethanolamine, methyldiethanolamine, diethylethanolamine, di- (3-hydroxypropyl) amine, N-tris (3-hydroxybutyl) amine, N-tris- (4-hydroxybutyl) amine, N-tris- (2-hydroxypropyl) amine, N-diisopropylethanolamine, N-diethylpropanolamine, N-diethyl- (2, 3-dihydroxypropyl) amine, N-ethyldiethanolamine, N-propyldiethanolamine, and combinations thereof. The functionalized silicon-based material is selected from the group consisting of linear, branched, star-shaped or cyclic aminopropyl-, aminobutyl-or aminoisobutyl-substituted siloxanes.

The traditional Chinese medicine is CN104548903A, which discloses an organic amine solvent for capturing carbon dioxide, and is characterized in that the organic amine solvent comprises 10-40% of a main absorption component, 5-20% of an absorption-assisting component, 0.05-1.0% of a corrosion inhibitor, 0.05-1.0% of an antioxidant and 30-84% of a mixed solvent by mass. The main absorption component is one or more of glycinate, polyether amine, morpholine and derivatives thereof, and polyethylene glycol dimethyl ether. The absorption-aiding component is one or more of diethylaminoethanol, 2-amino-2-methyl-1-propanol, N-methyldiethanolamine and hydroxyethyl ethylenediamine. The corrosion inhibitor is one or more of sodium metavanadate, sodium chromate and hexamethylenetetramine. The antioxidant is one or more of sodium sulfite, potassium sodium tartrate and antimony sodium tartrate. The mixed solvent is one or more of deionized water, methyl pyrrolidone and propylene carbonate. The initial degradation time reaches 226min at the longest, which shows that the formula of the decarburization solution has the best oxidation degradation resistance which is far higher than that of the comparative example, and the initial degradation time is prolonged by 4 to 7 times.

China petrochemical is CN105561756A, which discloses a compound solvent for capturing carbon dioxide and application thereof, wherein the solvent comprises a solvent containing amino ether oxy, alcohol amine and water. Wherein, the content of the solvent containing amino ether oxyl is 5 to 85 weight percent, the content of alcohol amine is 1.5 to 70 weight percent, and the content of water is 5 to 80 weight percent. The structural formula of the solvent containing amino and ether oxygen groups is NH₂-R1-(O-CHR3-CH₂) And x-R2, wherein R1 and R2 are independently selected from alkyl, alkyl substituted by hydroxyl, alkyl substituted by amino, or alkyl substituted by both amino and hydroxyl, R3 is alkyl or hydrogen, and x is 1-6. The carbon dioxide collecting device can be used for collecting carbon dioxide discharged by various low-concentration carbon dioxide discharge sources such as coal-fired boiler discharge gas of a power plant, cement and lime kiln gas, blast furnace gas, catalyst regeneration discharge gas of a refinery FCC device and the like at the temperature of 10-80 ℃. The method has the advantages of large absorption capacity, high absorption rate, high regeneration rate, high stability and the like, and has good prospect in the field of large-scale carbon dioxide capture. The alcohol amine is one or more of monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, and 2-amino-2-methyl-1-propanol.

At present, the mixed alcohol amine absorbent has characteristics in the aspects of carbon dioxide absorption capacity, absorption rate, analysis performance and regeneration energy consumption, but needs to further improve the comprehensive performance and stability of the absorbent in the aspects of carbon dioxide absorption capacity, absorption rate, analysis performance and regeneration energy consumption.

Disclosure of Invention

The technical problem to be solved by the invention is to provide an absorbent for carbon dioxide, which has better absorption rate, absorption capacity and regeneration rate, and particularly has better stability.

The technical scheme adopted by the invention is as follows: a carbon dioxide absorbent is characterized by comprising an alcohol amine main absorbent, piperazine serving as an absorption aid, an organic aid, activated carbon, carbon nanotubes and deionized water, wherein the organic aid is a mixture of dimethyl sulfoxide (DMSO) and Dimethylformamide (DMF); the dosage ratio is as follows:

30-50 parts of alcamines main absorbent and piperazine

10-15 parts of organic auxiliary agent

50-70 parts of deionized water

3-8 parts of activated carbon and carbon nanotubes.

Preferably, the molar ratio of DMSO to DMF is between 3:1 and 1:3, preferably 3: 2.

Preferably, the mass ratio of the activated carbon to the carbon nanotubes is 10-20:1, preferably 15: 1.

Preferably, the main alcohol amine absorbent is one or more of N-methyldiethanolamine, hydroxyethyl ethylenediamine and triethylene diamine.

Preferably, the mass ratio of the main alcohol amine absorbent to the piperazine is 10: 2-8.

Preferably, the organic adjuvant is used in an amount of 12 parts by weight.

Preferably, the absorbent has an absorption capacity of 0.85 or more and an absorption capacity of 0.80 or more after standing for 6 months.

Preferably, the degree of regeneration of the absorbent is 90% or more.

Preferably, the absorbent has an absorption temperature of 20 to 60 ℃ and an operating pressure of 0 to 0.2 MPa.

Preferably, the regeneration temperature of the absorbent is 80-110 ℃ and the operating pressure is 0-0.5 MPa.

Tests prove that the carbon dioxide absorbent can achieve better absorption rate, absorption capacity (more than 0.85) and regeneration degree, particularly has better stability, and the absorption capacity after being placed at room temperature for 6 months is kept above 0.80.

Wherein the absorption rate, absorption capacity and degree of regeneration are measured according to the method disclosed in CN 105080326A.

Detailed Description

Example 1:

a carbon dioxide absorbent is characterized by comprising an alcohol amine main absorbent, piperazine serving as an absorption aid, an organic aid, activated carbon, carbon nanotubes and deionized water, wherein the organic aid is a mixture of dimethyl sulfoxide (DMSO) and Dimethylformamide (DMF); the dosage ratio is as follows:

40 parts of main alcohol amine absorbent and 40 parts of piperazine, wherein the MDEA accounts for 30 parts by weight, and the piperazine accounts for 10 parts by weight; 10 parts of organic auxiliary agent, wherein the mol ratio of DMSO to DMF is 3: 1;

50 parts by weight of deionized water;

3 parts of activated carbon and carbon nano tubes by weight, wherein the mass ratio of the activated carbon to the carbon nano tubes is 10: 1.

All examples and comparative examples measure the average absorption rate, absorption capacity and regeneration degree of the carbon dioxide absorbent, and the absorption capacity after being left for 6 months, and the results are recorded in table 1. Wherein the absorption temperature is 20 ℃ and the regeneration temperature is 80 ℃.

Example 2:

otherwise as in example 1, the molar ratio of DMSO to DMF was 1: 3.

Example 3:

otherwise as in example 1, the molar ratio of DMSO to DMF was 3: 2.

Example 4:

otherwise, as in example 1, the mass ratio of the activated carbon to the carbon nanotubes was 20: 1.

Example 5:

otherwise, as in example 1, the mass ratio of activated carbon to carbon nanotubes was 15: 1.

Example 6:

in the same manner as in example 1, the alkanolamines as the main absorbent were N-methyldiethanolamine, hydroxyethylethylenediamine and triethylenediamine each in 10 parts by weight.

Example 7:

the rest of the organic auxiliary was 12 parts by weight as in example 1.

Example 8:

otherwise as in example 1, the primary alkanolamine absorbent is hydroxyethylethylenediamine.

Example 9:

otherwise, as in example 1, the primary alkanolamine absorbent is triethylenediamine.

Comparative example 1:

the procedure is as in example 1 except that no organic auxiliary is used.

Comparative example 2-a:

the organic adjuvant was only DMSO, and the procedure was otherwise the same as in example 1.

Comparative example 2-b:

the organic auxiliary agent is DMF only, and the rest is the same as example 1.

Comparative example 2-c:

the organic auxiliary was 20 parts by weight, and the rest was the same as in example 1.

Comparative examples 2-d:

the organic auxiliary was 5 parts by weight, and the rest was the same as in example 1.

Comparative example 3:

the same procedure as in example 1 was repeated, except that activated carbon and carbon nanotubes were not used.

Comparative example 4:

the same procedure as in example 1 was repeated, except that no organic auxiliary was used, and no activated carbon or nanotubes were used.

Comparative example 5-a:

the same procedure as in example 1 was repeated except that 3 parts by weight of activated carbon was used alone.

Comparative example 5-b:

the same procedure as in example 1 was repeated except that 3 parts by weight of carbon nanotubes were used.

Comparative example 5-c:

the amount of activated carbon and carbon nanotubes used was 10 parts by weight, and the rest was the same as in example 1.

Comparative examples 5-d:

the amount of activated carbon and carbon nanotubes used was 2 parts by weight, and the rest was the same as in example 1.

TABLE 1

As can be seen, the organic auxiliary had a greater effect on the stability in example 1 compared to comparative example 1. In example 1 compared to the four groups of comparative example 2, the choice of organic adjuvant has an impact on both capacity and stability.

Example 1 compared to comparative example 3, activated carbon and carbon nanotubes all have an impact on the rate of absorption, capacity and stability. Example 1 in comparison to comparative example 4, the use of an organic solvent with activated carbon and carbon nanotubes may act synergistically. Meanwhile, the stability and the capacity are improved.

In example 1, compared with the four groups of comparative example 5, stability and capacity are affected by using activated carbon or carbon nanotubes alone or by excessively large or small mixing ratio of the activated carbon or the carbon nanotubes.

Further, in comparison of example 1 with examples 2-3, the molar ratio of DMSO to DMF is optimally 3: 2. the mass ratio of activated carbon to carbon nanotubes is optimally 15:1 for example 1 versus examples 4-5.

Compared with the examples 6 and 8-9, the main absorbent of the alcamines is N-methyldiethanolamine, hydroxyethylethylenediamine and triethylenediamine, each 10 weight parts, which has better effect than that of using any one of the three alone.

As can be seen from a comparison of example 1 with example 7, the organic auxiliary is used in an optimum amount of 12 parts by weight.

Claims

1. A carbon dioxide absorbent is characterized by comprising an alcohol amine main absorbent, piperazine serving as an absorption aid, an organic aid, activated carbon, carbon nanotubes and deionized water, wherein the organic aid is a mixture of dimethyl sulfoxide (DMSO) and Dimethylformamide (DMF); the dosage ratio is as follows:

30-50 parts of an alcamines main absorbent and piperazine, wherein the mass ratio of the alcamines main absorbent to the piperazine is 10: 2-8; 10-15 parts of organic auxiliary agent

50-70 parts of deionized water

3-8 parts of activated carbon and carbon nanotubes;

wherein the mol ratio of DMSO to DMF is 3: 2;

the mass ratio of the activated carbon to the carbon nano tubes is 15: 1;

the absorbent has an absorption capacity of 0.85 or more, and an absorption capacity of 0.80 or more after standing for 6 months.

2. The carbon dioxide absorbent according to claim 1, wherein the main alcohol amine absorbent is one or more of N-methyldiethanolamine, hydroxyethylethylenediamine and triethylenediamine.

3. The carbon dioxide absorbent according to claim 1, wherein the organic auxiliary is used in an amount of 12 parts by weight.

4. The carbon dioxide absorbent according to claim 1, wherein the absorbent is regenerated to a degree of 90% or more.

5. The carbon dioxide absorbent according to claim 1, wherein the absorbent has an absorption temperature of 20 to 60 ℃ and an operating pressure of 0 to 0.2 MPa.

6. The carbon dioxide absorbent according to claim 1, wherein the absorbent has a regeneration temperature of 80 to 110 ℃ and an operating pressure of 0 to 0.5 MPa.