Carbon dioxide absorbent, preparation method and application thereof

Abstract

The application belongs to the technical field of mixed gas separation and purification, and particularly relates to a carbon dioxide absorbent as well as a preparation method and application thereof. The carbon dioxide absorbent contains a main agent, an auxiliary agent and an active agent. The main agent is a steric hindered amine containing one N atom, the auxiliary agent is a primary amine compound, and the active agent is a cyclic polyamino organic amine. The weight ratio of the main agent to the auxiliary agent is 1.5-3:1. The carbon dioxide absorbent prepared by the application has a high absorption rate when absorbing and capturing carbon dioxide, and can improve the regeneration rate and the cycle capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mixed gas separation and purification, and particularly relates to a carbon dioxide absorbent and a preparation method and application thereof. BACKGROUND

[0002] In recent years, due to the large emission of greenhouse gases caused by human activities, the continuous deterioration of the greenhouse effect makes global warming seemingly uncontrollable. In order to effectively inhibit global warming, it is necessary to effectively control the emission of greenhouse gases. Greenhouse gases mainly include carbon dioxide, methane, ozone, nitrogen oxides, etc., among which carbon dioxide is the greenhouse gas that contributes most to the greenhouse effect, and the carbon dioxide emitted in the process of burning fossil fuels occupies a dominant position. In order to effectively alleviate the impact of the greenhouse effect, the emitted carbon dioxide should be recycled and utilized.

[0003] At present, the mainstream technology route that can achieve carbon dioxide emission reduction in a short term is CCUS technology, which mainly includes pre-combustion capture, in-combustion capture and post-combustion capture. The pre-combustion capture mainly includes integrated gasification combined cycle technology (IGCC); the in-combustion capture includes oxygen-enriched combustion technology and chemical looping combustion technology; the post-combustion capture technology mainly includes chemical absorption technology, adsorption technology, membrane separation technology and low-temperature distillation technology. Among them, the post-combustion capture technology is the most commonly used technology in power plants because it has less modification to the power plant, less initial investment and relatively mature process. Among the various technologies of post-combustion capture, the chemical absorption technology has a long history, mature technology and stable operation, and several demonstration platforms have been built. Among them, ethanol amine (MEA) is the earliest chemical absorbent to realize commercial application, which has the advantage of fast absorption rate, but has the problems of small absorption capacity, high regeneration energy consumption, fast degradation rate and strong corrosion. Therefore, developing a new absorbent with high absorption rate, high regeneration rate, large circulation capacity and low regeneration energy consumption is the key to reducing the energy consumption of the carbon capture system and improving the economic benefit of the system.

[0004] A single absorbent is difficult to meet the requirements of high absorption rate, high absorption capacity and low reaction heat at the same time, therefore, mixing different organic amines with different properties to obtain a new absorbent with high absorption rate and absorption capacity, high regeneration rate and low regeneration energy consumption has become one of the current research hotspots. At present, there are also related patents that mix multiple absorbents to prepare a carbon dioxide absorbent, for example, a non-water absorbent effectively improves the absorption rate and absorption capacity, but has the problems of large viscosity and low stability, and the absorbent has large flow resistance in the system, which can easily cause the reduction of equipment life and the increase of operation cost, etc. A two-phase absorbent effectively improves the absorption capacity, and only the lean water phase needs to be regenerated, which can effectively reduce the regeneration energy consumption, but the above-mentioned absorbents have the problems of large viscosity of the rich phase and water balance, therefore, they have not realized large-scale industrial application. SUMMARY

[0005] The present application aims at solving the problems of low absorption rate and absorption capacity of single absorbent, and large viscosity and low stability of multi-component absorbent such as non-aqueous absorbent, and imbalance of water balance due to large viscosity of rich phase of two-phase absorbent in the prior art, and provides a carbon dioxide absorbent and a preparation method and application thereof. The carbon dioxide absorbent is obtained by mixing raw materials including a main agent of a steric-hindered amine containing one N atom, an auxiliary agent of a primary amine compound, and an active agent of a cyclic multi-amino organic compound, and by precisely controlling the ratio between the main agent and the auxiliary agent, so that the prepared carbon dioxide absorbent has a high absorption rate when absorbing carbon dioxide, and can improve the regeneration rate and the circulation capacity.

[0006] To achieve the above-mentioned object, the present application provides a carbon dioxide absorbent containing a main agent, an auxiliary agent and an active agent, the main agent being a steric-hindered amine containing one N atom, the auxiliary agent being a primary amine compound, and the active agent being a cyclic multi-amino organic amine, and the weight ratio of the main agent to the auxiliary agent being 1.5-3:1, preferably 1.8-2.2:1.

[0007] Preferably, the content of the active agent is 5-35% by weight based on 100% by weight of the total weight of the main agent and the auxiliary agent.

[0008] Preferably, the steric-hindered amine containing one N atom has a structure as shown in formula (1),

[0009]

[0010] wherein R1 and R2 are each independently selected from -OH, -C m H 2m+1 and -C n H 2n OH, and m and n are integers of 1-6.

[0011] Preferably, the steric-hindered amine containing one N atom is selected from one or more than two of 2-amino-2-methyl-1-propanol, 2-amino-2-hydroxymethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol and 2-amino-2-ethyl-1,3-propanediol, and more preferably is 2-amino-2-methyl-1-propanol.

[0012] Preferably, the primary amine compound is selected from one or more than two of diglycolamine, 3-amino-1-propanol and ethanolamine, and more preferably is ethanolamine.

[0013] Preferably, the cyclic multi-amino organic amine is piperazine and / or N-aminoethylpiperazine.

[0014] Preferably, the carbon dioxide absorbent is in the form of an aqueous solution, and in the aqueous solution, the total concentration of the main agent, the auxiliary agent and the active agent is 30-50% by weight.

[0015] The second aspect of the present application provides a preparation method of the above-mentioned carbon dioxide absorbent, which comprises mixing the main agent, the auxiliary agent, the active agent and a solvent.

[0016] The third aspect of the present application provides the use of the above-mentioned carbon dioxide absorbent in absorbing carbon dioxide.

[0017] Preferably, the conditions for the carbon dioxide absorbent to absorb carbon dioxide include a temperature of 30-50℃ and a pressure of 1-1.5 bar.

[0018] Through the above technical solutions, the beneficial effects of the present application at least include the following aspects:

[0019] (1) The present application uses the main agent, the auxiliary agent and the active agent of specific components as raw materials to prepare the carbon dioxide absorbent, and by compounding the main agent, the auxiliary agent and the active agent, the prepared carbon dioxide absorbent can have a high absorption rate when absorbing and capturing carbon dioxide.

[0020] (2) The main agent, the auxiliary agent and the active agent of specific components are compounded and used, and the proportion between the main agent and the auxiliary agent is accurately controlled, which can improve the regeneration rate and the cycle capacity of the prepared carbon dioxide absorbent. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the absorption rate curve of Examples 1-7;

[0022] Figure 2 is the absorption rate curve of Comparative Examples 1-5;

[0023] Figure 3 is the regeneration rate curve of Examples 1-7;

[0024] Figure 4 is the regeneration rate curve of Comparative Examples 1-5; DETAILED DESCRIPTION

[0025] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0026] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the invention. Any numeric range recited is intended to include all values from the lower value to the upper value, inclusive of both values, and to sub-ranges falling within the specified range. In this context, individual points within a range should be considered as being included within the range, and individual points can be combined to form new ranges, which are to be considered as being included within the present disclosure.

[0027] The first aspect of the present application provides a carbon dioxide absorbent containing a main agent, an auxiliary agent and an active agent. The main agent is a steric hindrance amine containing one N atom, the auxiliary agent is a primary amine compound, and the active agent is a cyclic polyamino organic amine.

[0028] In the carbon dioxide absorbent of the present application, the ratio of the main agent to the auxiliary agent is controlled within a suitable range, which can improve the absorption performance and regeneration performance of the absorbent. The weight ratio of the main agent to the auxiliary agent is 1.5-3:1, preferably 1.8-2.2:1, for example 1.8:1, 1.9:1, 2.0:1, 2.1:1 or 2.2:1.

[0029] In the carbon dioxide absorbent of the present application, in a preferred embodiment, the use amount of the main agent, the auxiliary agent and the active agent is controlled within a suitable range, which can further improve the absorption performance and regeneration performance of the prepared absorbent. The content of the active agent is 5-35 wt%, more preferably 5-30 wt%, for example 5 wt%, 10 wt%, 19 wt%, 25 wt% or 30 wt%, based on 100 wt% of the total weight of the main agent and the auxiliary agent.

[0030] In the carbon dioxide absorbent of the present application, compared with ethanolamine (MEA), the steric hindrance amine containing one N atom is used as the main agent, the reaction rate of the prepared carbon dioxide absorbent is higher, the regeneration rate and the cycle capacity are higher than those of ethanolamine (MEA) at the same concentration, the regeneration energy consumption is lower than that of ethanolamine (MEA) at the same concentration, and therefore the steric hindrance amine containing one N atom has great potential in reducing energy consumption and saving process cost.

[0031] In the carbon dioxide absorbent of the present application, the term "steric hindrance amine" refers to an organic amine compound in which the amino group is connected to a tertiary carbon atom or a secondary carbon atom, and has a steric hindrance amine effect.

[0032] In the carbon dioxide absorbent of the present application, in a specific embodiment, the structure of the steric hindrance amine containing one N atom is shown in formula (1),

[0033]

[0034] wherein R1and R2are each independently selected from the group consisting of -OH, -C m H 2m+1 and -C n H 2n OH, m and n are integers from 1 to 6.

[0035] In the carbon dioxide absorbent of the present application, the sterically hindered amines similar to the structure of 2-amino-2-methyl-1-propanol (AMP) also have high absorption rate, high regeneration rate and high cycle capacity, and thus can be used as the main absorbent instead of AMP.

[0036] In a preferred embodiment, the sterically hindered amine containing one N atom is selected from one or more than two of 2-amino-2-methyl-1-propanol, 2-amino-2-hydroxymethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol and 2-amino-2-ethyl-1,3-propanediol. In a more preferred embodiment, the sterically hindered amine containing one N atom is 2-amino-2-methyl-1-propanol.

[0037] In the carbon dioxide absorbent of the present application, in a specific embodiment, the main agent is added with an auxiliary agent and an active agent, and the main agent, the auxiliary agent and the active agent are used in combination, which can further improve the absorption rate and the regeneration rate of the absorbent, reduce the regeneration energy consumption of the absorbent, and has great potential in the field of CO2 capture.

[0038] In the carbon dioxide absorbent of the present application, the auxiliary agent is a primary amine compound, and the term "primary amine compound" refers to an organic amine compound in which one H in NH3 is replaced by a hydrocarbon group.

[0039] In the carbon dioxide absorbent of the present application, in a specific embodiment, the primary amine compound is selected from one or more than two of diglycolamine, 3-amino-1-propanol and ethanolamine. In a preferred embodiment, the primary amine compound is ethanolamine.

[0040] In the carbon dioxide absorbent of the present application, the active agent is a cyclic polyamino organic amine, and the term "cyclic polyamino organic amine" refers to an organic amine compound having a cyclic structure and containing one or more than one amino group / imino group / hypoimino group.

[0041] In the carbon dioxide absorbent of the present application, in a specific embodiment, the cyclic polyamino organic amine is piperazine and / or N-aminoethylpiperazine.

[0042] In the carbon dioxide absorbent of the present application, in a specific embodiment, the carbon dioxide absorbent is in the form of an aqueous solution, and in the aqueous solution, the total concentration of the main agent, the auxiliary agent and the active agent is 30-50% by weight, preferably 38-42% by weight, for example 38% by weight, 40% by weight or 42% by weight.

[0043] In the carbon dioxide absorbent of the present application, in a specific embodiment, the solvent used in the carbon dioxide absorbent is water.

[0044] The carbon dioxide absorbent of the present application can be widely used in the removal and capture of acidic gases in mixed gases, such as the capture of CO2 and the like from the tail flue gas of a thermal power plant, the tail flue gas of a cement kiln and the like.

[0045] In a specific embodiment, the carbon dioxide absorbent of the present application is a mixed solution containing 2-amino-2-methyl-1-propanol, ethanolamine, piperazine and water, the weight ratio of the 2-amino-2-methyl-1-propanol and the ethanolamine is 1.8-2.0:1, wherein the total content of the 2-amino-2-methyl-1-propanol and ethanolamine is 35-38% by weight, the content of the piperazine is 2-5% by weight, and the content of the water is 57-60% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0046] In another specific embodiment, the carbon dioxide absorbent of the present application is a mixed solution containing 2-amino-2-hydroxymethyl-1,3-propanediol, ethanolamine, piperazine and water, the weight ratio of the 2-amino-2-hydroxymethyl-1,3-propanediol and the ethanolamine is 2.0-2.2:1, wherein the total content of the 2-amino-2-hydroxymethyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-63% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0047] In another specific embodiment, the carbon dioxide absorbent of the present application is a mixed solution containing 2-amino-2-methyl-1,3-propanediol, ethanolamine, N-aminoethyl piperazine and water, the weight ratio of the 2-amino-2-methyl-1,3-propanediol and the ethanolamine is 1.8-2.2:1, wherein the total content of the 2-amino-2-methyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-60% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0048] In another embodiment, the carbon dioxide absorbent of the present application is a mixture containing 2-amino-2-ethyl-1,3-propanediol, ethanolamine, N-aminoethylpiperazine and water, the weight ratio of the 2-amino-2-ethyl-1,3-propanediol and ethanolamine being 1.5-1.8:1, wherein the total content of the 2-amino-2-ethyl-1,3-propanediol and ethanolamine is 32-38% by weight, the content of the piperazine is 2-8% by weight, and the content of the water is 55-60% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0049] In another embodiment, the carbon dioxide absorbent of the present application is a mixture containing 2-amino-2-ethyl-1,3-propanediol, ethanolamine, N-aminoethylpiperazine and water, the weight ratio of the 2-amino-2-ethyl-1,3-propanediol and ethanolamine being 2.2-3:1, wherein the total content of the 2-amino-2-ethyl-1,3-propanediol and ethanolamine is 35-38% by weight, the content of the piperazine is 2-8% by weight, and the content of the water is 57-60% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0050] The second aspect of the present application provides a method for preparing the carbon dioxide absorbent as described above, which comprises mixing the main agent, the auxiliary agent, the active agent and the solvent under stirring.

[0051] In the method of the present application, the carbon dioxide absorbent is prepared by mixing and stirring the raw materials, and the stirring condition will affect the absorption performance of the carbon dioxide absorbent.

[0052] In the method of the present application, in an embodiment, the stirring condition comprises a stirring speed of 400-600 r / min, for example, 400 r / min, 450 r / min, 500 r / min, 550 r / min or 600 r / min, and a stirring time of 5-15 min, for example, 6 min, 8 min, 10 min, 12 min or 14 min.

[0053] In an embodiment, the method for preparing the carbon dioxide absorbent of the present application comprises mixing 2-amino-2-methyl-1-propanol, ethanolamine, piperazine and water and stirring at 500-600 r / min for 10-15 min, wherein the weight ratio of the 2-amino-2-methyl-1-propanol and the ethanolamine is 1.8-2.0:1, wherein the total content of the 2-amino-2-methyl-1-propanol and ethanolamine is 35-38% by weight, the content of the piperazine is 2-5% by weight, and the content of the water is 57-60% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0054] In another embodiment, the method for preparing the carbon dioxide absorbent of the present application comprises mixing 2-amino-2-hydroxymethyl-1,3-propanediol, ethanolamine, piperazine and water and stirring at 500-600 r / min for 10-15 min, wherein the weight ratio of the 2-amino-2-hydroxymethyl-1,3-propanediol and the ethanolamine is 2.0-2.2:1, wherein the total content of the 2-amino-2-hydroxymethyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-63% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0055] In another embodiment, the method for preparing the carbon dioxide absorbent of the present application comprises mixing 2-amino-2-hydroxymethyl-1,3-propanediol, ethanolamine, piperazine and water and stirring at 500-600 r / min for 10-15 min, wherein the weight ratio of the 2-amino-2-hydroxymethyl-1,3-propanediol and the ethanolamine is 2.0-2.2:1, wherein the total content of the 2-amino-2-hydroxymethyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-63% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0056] In another embodiment, the method for preparing the carbon dioxide absorbent of the present application comprises mixing 2-amino-2-hydroxymethyl-1,3-propanediol, ethanolamine, piperazine and water and stirring at 500-600 r / min for 10-15 min, wherein the weight ratio of the 2-amino-2-hydroxymethyl-1,3-propanediol and the ethanolamine is 2.0-2.2:1, wherein the total content of the 2-amino-2-hydroxymethyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-63% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0057] In another embodiment, the method for preparing the carbon dioxide absorbent of the present application comprises mixing 2-amino-2-hydroxymethyl-1,3-propanediol, ethanolamine, piperazine and water and stirring at 500-600 r / min for 10-15 min, wherein the weight ratio of the 2-amino-2-hydroxymethyl-1,3-propanediol and the ethanolamine is 2.0-2.2:1, wherein the total content of the 2-amino-2-hydroxymethyl-1,3-propanediol and ethanolamine is 32-35% by weight, the content of the piperazine is 5-8% by weight, and the content of the water is 57-63% by weight, based on the total weight of the carbon dioxide absorbent being 100% by weight.

[0058] The third aspect of the present application provides the use of the above-mentioned carbon dioxide absorbent in absorbing carbon dioxide.

[0059] In a specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide, and the absorption process can be carried out in a conventional one-stage absorption tower or a two-stage absorption tower with inter-stage cooling.

[0060] In a specific embodiment, the conditions for the carbon dioxide absorbent of the present application to absorb carbon dioxide include a temperature of 30-50°C, such as 30°C, 35°C, 40°C, 45°C or 50°C, and a pressure of 1-1.5 bar, such as 1 bar, 1.1 bar, 1.2 bar, 1.3 bar, 1.4 bar or 1.5 bar.

[0061] In a specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide in a conventional one-stage absorption tower at a temperature of 30-35°C and a pressure of 1-1.1 bar.

[0062] In another specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide in a conventional one-stage absorption tower at a temperature of 35-45°C and a pressure of 1.1-1.2 bar.

[0063] In another specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide in a two-stage absorption tower with inter-stage cooling at a temperature of 40-50°C and a pressure of 1.2-1.3 bar.

[0064] In another specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide in a two-stage absorption tower with inter-stage cooling at a temperature of 30-50°C and a pressure of 1.3-1.4 bar.

[0065] In another specific embodiment, the carbon dioxide absorbent of the present application is used to absorb carbon dioxide in a two-stage absorption tower with inter-stage cooling at a temperature of 45-50°C and a pressure of 1.4-1.5 bar.

[0066] In the present application, the carbon dioxide absorbent after absorbing carbon dioxide needs to be regenerated and reused, and the regeneration process can be carried out in a tower-type regeneration tower or by using a flash regeneration process.

[0067] In the specific embodiment, the regeneration conditions of the carbon dioxide absorbent include: temperature of 90-120℃, for example, can be 90℃, 100℃, 110℃ or 120℃, pressure of 1-1.5bar, for example, can be 1bar, 1.1bar, 1.2bar, 1.3bar, 1.4bar or 1.5bar.

[0068] In the present application, the carbon dioxide absorbent needs to be heat exchanged when absorbing or recycling the carbon dioxide, and the heat exchange process can select a conventional lean-rich heat exchanger or a plate heat exchanger.

[0069] The present application will be described in detail below by way of examples, but the scope of protection of the present application is not limited thereto.

[0070] In the examples and comparative examples of the present application, the reagents used are all commercially available unless otherwise specified.

[0071] Examples 1-7 and Comparative Examples 1-5 are used to illustrate the preparation process of the carbon dioxide absorbent.

[0072] Example 1

[0073] Mix 25.3g of 2-amino-2-methyl-1-propanol, 12.6g of ethanolamine, 2.0g of piperazine and 60g of deionized water, stir at 450r / min for 10min to obtain the carbon dioxide absorbent.

[0074] Example 2

[0075] Mix 24.0g of 2-amino-2-methyl-1-propanol, 12.0g of ethanolamine, 4.0g of piperazine and 60g of deionized water, stir at 500r / min for 10min to obtain the carbon dioxide absorbent.

[0076] Example 3

[0077] Mix 22.6g of 2-amino-2-methyl-1-propanol, 11.3g of ethanolamine, 6.0g of piperazine and 60g of deionized water, stir at 550r / min for 15min to obtain the carbon dioxide absorbent.

[0078] Example 4

[0079] Mix 21.3g of 2-amino-2-methyl-1-propanol, 10.6g of ethanolamine, 8.0g of piperazine and 60g of deionized water, stir at 600r / min for 15min to obtain the carbon dioxide absorbent.

[0080] Example 5

[0081] Mixing 20.0 g of 2-amino-2-methyl-1-propanol, 13.3 g of ethanolamine, 6.7 g of piperazine, and 60 g of deionized water, stirring at 550 r / min for 12 min, a carbon dioxide absorbent was obtained.

[0082] Example 6

[0083] Mixing 24.0 g of 2-amino-2-methyl-1-propanol, 8.0 g of ethanolamine, 8.0 g of piperazine, and 60 g of deionized water, stirring at 550 r / min for 15 min, a carbon dioxide absorbent was obtained.

[0084] Example 7

[0085] Mixing 38.7 g of 2-amino-2-methyl-1-propanol, 19.3 g of ethanolamine, 2.0 g of piperazine, and 40 g of deionized water, stirring at 450 r / min for 10 min, a carbon dioxide absorbent was obtained.

[0086] Comparative Example 1

[0087] Mixing 30.0 g of ethanolamine (MEA) and 70.0 g of deionized water, stirring at 400 r / min for 10 min, a carbon dioxide absorbent was obtained.

[0088] Comparative Example 2

[0089] Mixing 38.0 g of 2-amino-2-methyl-1-propanol, 2.0 g of piperazine, and 60 g of deionized water, stirring at 450 r / min for 12 min, a carbon dioxide absorbent was obtained.

[0090] Comparative Example 3

[0091] Mixing 25.0 g of 2-amino-2-methyl-1-propanol, 15.0 g of ethanolamine, and 60 g of deionized water, stirring at 400 r / min for 10 min, a carbon dioxide absorbent was obtained.

[0092] Comparative Example 4

[0093] Mixing 18.0 g of 2-amino-2-methyl-1-propanol, 18.0 g of ethanolamine, 4.0 g of piperazine, and 60 g of deionized water, stirring at 450 r / min for 12 min, a carbon dioxide absorbent was obtained.

[0094] Comparative Example 5

[0095] Mixing 28.8 g of 2-amino-2-methyl-1-propanol, 7.2 g of ethanolamine, 4.0 g of piperazine, and 60 g of deionized water, stirring at 500 r / min for 12 min, a carbon dioxide absorbent was obtained.

[0096] Test Example

[0097] The cycle capacity, absorption rate and regeneration rate of the carbon dioxide absorbent prepared in Examples 1-7 and Comparative Examples 1-5 were determined and calculated, and the results are shown in Table 1, Figure 1 , Figure 2 , Figure 3 and Figure 4 .

[0098] The carbon dioxide absorbent absorption process: the mixed gas of 12% CO2 by volume fraction + 88% N2 was introduced into the bubbling reactor at a water bath temperature of 40 DEG C to carry out the absorption reaction, and the outlet CO2 concentration was recorded by software, and the reaction was ended when the outlet concentration was basically unchanged.

[0099] The carbon dioxide absorbent regeneration process: after the absorption reaction was completed, the saturated rich liquid was taken out, weighed and then put into a three-necked flask, and the desorption experiment was carried out at a stirring speed of 20% and an oil bath temperature of 120 DEG C.

[0100] Absorption rate: the amount (mol) of CO2 absorbed by 1 kg of absorbent solution per unit time (s).

[0101] Regeneration rate: the amount (mol) of CO2 desorbed by 1 g of absorbent solution per unit time (s).

[0102] Cycle capacity: the difference between the amount of CO2 absorbed by unit mass of amine in the rich liquid and the amount of CO2 enriched by unit mass of amine in the lean liquid after desorption.

[0103] Table 1

[0104] Cycling capacity (mol / kg) Example 1 2.01 Example 2 1.76 Example 3 2.12 Example 4 1.88 Example 5 1.75 Example 6 1.68 Example 7 1.92 Comparative Example 1 0.99 Comparative Example 2 1.41 Comparative Example 3 1.38 Comparative Example 4 1.25 Comparative Example 5 1.37

[0105] From Figure 1 and Figure 2 , it can be seen that by compounding the main agent, auxiliary agent and active agent of specific components, and simultaneously accurately controlling the ratio between the main agent and the auxiliary agent, the initial absorption rate of the carbon dioxide absorbent prepared in Examples 1-7 is generally improved, and compared with Comparative Examples 1-5, the absorption rate of the carbon dioxide absorbent prepared in Examples 1-7 decreases slowly with time; from Figure 3 and Figure 4It can be seen that the regeneration rate of the carbon dioxide absorbent prepared in Examples 1-7 reaches a maximum value in 5-15 min, and the maximum value is close to 2.8 ml / g·min, and the regeneration rate gradually decreases with the time constantly extending, and approaches 0 ml / g·min at about 60 min, while the regeneration rate of the carbon dioxide absorbent prepared in Comparative Examples 1-5 also reaches a maximum value in 5-15 min, but the maximum value is close to 2.0 ml / g·min, and the regeneration rate gradually decreases with the time constantly extending, and approaches 0 ml / g·min at about 50 min, thus it can be seen that compared with Comparative Examples 1-5, the carbon dioxide absorbent prepared in Examples 1-7 can improve the regeneration rate of the absorbent; it can be seen from Table 1 that compared with Comparative Examples 1-5, the carbon dioxide absorbent prepared in Examples 1-7 has a higher cycle capacity.

[0106] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent transformation or direct or indirect application in other related technical fields by using the content of the present application is also included in the patent protection scope of the present application.

Claims

1. A carbon dioxide absorbent, characterized by, The carbon dioxide absorbent is composed of a main agent, an auxiliary agent, an active agent and a solvent, the main agent is 2-amino-2-methyl-1-propanol, the auxiliary agent is ethanolamine, the active agent is piperazine, and the solvent is water, the weight ratio of the main agent to the auxiliary agent is 1.8-2:1, the content of the main agent and the auxiliary agent is 35-38% by weight, the content of the active agent is 2-5% by weight, and the content of the water is 57-60% by weight, based on 100% by weight of the total weight of the carbon dioxide absorbent.

2. A method of producing the carbon dioxide absorbent according to claim 1, characterized by, The method comprises mixing a main agent, an auxiliary agent, an active agent and a solvent.

3. The carbon dioxide absorbent of claim 1 is used for absorbing carbon dioxide.

4. Use according to claim 3, characterized in that, The conditions for absorbing carbon dioxide by the carbon dioxide absorbent include that the temperature is 30-50 DEG C and the pressure is 1-1.5 bar.

Images