阅读说明：本技术 一种用于二氧化碳捕获阈值可控的液-液相变吸收剂 (Liquid-liquid phase change absorbent with controllable carbon dioxide capture threshold ) 是由 梁志武 高红霞 吕娟 王楠 于 2021-09-10 设计创作，主要内容包括：本发明公开了一种用于二氧化碳捕获的液-液相变吸收剂,由伯胺、仲胺、有机溶剂和水构成。伯胺指单乙醇胺(MEA),仲胺指2-(乙氨基)乙醇(EAE),有机溶剂指环丁砜。液-液相变吸收剂在吸收CO-(2)前为单相,吸收CO-(2)后变为两相。液-液相变吸收剂分相后,CO-(2)主要集中在其中一相(CO-(2)富相),将CO-(2)富相与CO-(2)贫相分离,富相通过高温加热的方式再生。本发明的一种用于二氧化碳捕获的液-液相变吸收剂的CO-(2)吸收性能良好、分相迅速、CO-(2)负载阈值可控且传质性能优秀,再生稳定性良好。相比传统的CO-(2)吸收剂,大幅降低了再生能耗,具有广泛的应用前景。(The invention discloses a liquid-liquid phase change absorbent for capturing carbon dioxide, which consists of primary amine, secondary amine, an organic solvent and water. The primary amine refers to Monoethanolamine (MEA), the secondary amine refers to 2- (ethylamino) ethanol (EAE), and the organic solvent refers to sulfolane. Liquid-liquid phase change absorbent for absorbing CO 2 Single phase front, absorbing CO 2 Then two phases are formed. After phase separation of the liquid-liquid phase change absorbent, CO 2 Mainly concentrated in one of the phases (CO) 2 Rich phase) of CO 2 Rich phase and CO 2 The lean phase is separated and the rich phase is regenerated by high temperature heating. CO of liquid-liquid phase change absorbent for carbon dioxide capture 2 Good absorption performance, rapid phase separation, and high CO content 2 The load threshold is controllable, the mass transfer performance is excellent, and the regeneration stability is good. Compared with the conventional CO 2 The absorbent greatly reduces the regeneration energy consumption and has wide application prospect.)

1. A liquid-liquid phase change absorbent for carbon dioxide capture, characterized by consisting of a primary or secondary amine, an organic solvent and water; the primary amine is Monoethanolamine (MEA), the secondary amine is 2- (ethylamino) ethanol (EAE), and the organic solvent is sulfolane.

2. The liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1, wherein the concentration of said primary amine and secondary amine is varied from 1mol/L to 5mol/L, the concentration of said organic solvent is varied from 3mol/L to 5mol/L, and the remaining component is water.

3. A liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1, characterized in thatCharacterized in that the liquid-liquid phase change absorbent absorbs CO₂Former being homogeneous and absorbing CO₂The post-absorber changes to two phases, the upper phase being CO₂Rich phase, lower phase of CO₂Lean phase, in which CO is absorbed₂Mainly focusing on the upper phase.

4. A liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1 wherein said liquid-liquid phase change absorbent absorbs CO₂The post-absorber becomes two-phase in which CO₂The volume of the rich phase accounts for 30-80% of the total volume of the absorbent.

5. A liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1, wherein said liquid-liquid phase change absorbent is for absorbing CO₂The volume fraction of the gas is 5-20%, the absorption temperature is 30-50 ℃, and the absorption load is 0.40mol CO₂0.55mol CO per mol of amine₂Per mol of amine.

6. A liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1 wherein said liquid-liquid phase change absorbent absorbs CO₂After phase separation, only rich phase desorption is needed for regeneration, and the regeneration mode is high-temperature heating.

7. A liquid-liquid phase change absorbent for carbon dioxide capture as claimed in claim 1 wherein the regeneration process conditions are: the regeneration temperature is 70-120 ℃, and the regeneration time is 30-150 min.

8. A method for CO according to any one of claims 1 to 7₂Use of a captured liquid-liquid phase change absorbent in the field of carbon dioxide capture.

9. The method for CO of claim 8₂Use of a captured liquid-liquid phase change absorbent in the field of carbon dioxide capture, characterized in that it comprises the steps of:

s1, preparing a liquid-liquid phase change absorbent by using the primary amine and the secondary amine as main absorbents and the sulfolane as a phase separation agent, wherein the concentration of the primary amine is different from 1mol/L to 5mol/L, the concentration of the secondary amine is different from 1mol/L to 5mol/L, the mass fraction of the organic solvent is different from 3mol/L to 5mol/L, and the balance of components is water;

s2, absorbing CO by the liquid-liquid phase change absorbent of S1₂5-20% of gas by volume, the absorption temperature is 30-50 ℃, and the absorption load is 0.40mol CO₂0.55mol CO per mol of amine₂Per mol of amine. The liquid-liquid phase change absorbent changes into two phases, wherein the upper phase is CO₂Rich phase, lower phase of CO₂Lean phase, CO₂Mainly focused on the upper phase;

s3, mixing the CO of S2₂Rich phase CO desorption by heating₂Regenerating the rich phase at 70-120 deg.C for 30-150 min to obtain regenerated absorbent and CO₂Mixing the lean phase to obtain a liquid-liquid phase change absorbent, CO₂And sending to the next working section.

Technical Field

The invention relates to post combustion CO₂The field of capture, in particular to a phase change absorbent for absorbing CO₂The method of (1).

Background

Global warming is one of the most concerned problems in the world today, and the main cause of this problem is CO₂And the like. At present, CO₂The capture and utilization technology (CCUS) is to realize CO₂The main ways of reducing emission and coping with global warming. Common CO₂The capture method is usually carried out in the following wayThe following are provided: pre-combustion capture, oxycombustion capture, and post-combustion capture. The post-combustion capture technology does not need to modify the existing device, has the advantages of wide application range and strong inheritance, and has become the main research direction at present.

The post-combustion capture technology mainly comprises a chemical solvent absorption method, a physical absorption method, a membrane separation method and the like. In the chemical solvent absorption method, the organic amine solvent has high absorption efficiency, can regenerate and desorb CO₂The characteristics of high purity and the like are more mature in industry. However, the traditional organic amine solvent has the defects of easy corrosion and degradation, high regeneration energy consumption, low cycle load and the like. Over the last decades, researchers have been working on developing new structurally modified and built amines, new absorption-desorption processes and high efficiency gas-liquid mass transfer equipment to reduce CO₂Energy consumption during absorption-desorption.

Phase change absorbents are considered to be revolutionary CO₂Absorbent with significant CO reduction₂Potential for absorbing energy consumption. The phase change absorbent means that the absorbent absorbs CO₂In which CO is converted into a phase in the solution during or after absorption₂The carbamate and the bicarbonate are enriched in one phase, only the enriched phase needs to be desorbed, and the regeneration volume of the absorption liquid is greatly reduced, so that the energy consumption can be obviously reduced. At present, the phase change absorbent mainly takes organic amine as a main component, and lipophilic amine, alcohols, ionic liquid and the like are added to prepare the trapping agent with phase change potential according to a certain proportion.

Disclosure of Invention

In view of the above-mentioned disadvantages, the present invention provides a liquid-liquid phase change absorbent for carbon dioxide capture. The absorbent can absorb CO₂Then will be divided into two phases, wherein the upper phase is CO₂The enriched phase can enrich most of CO₂The main components are MEA, EAE and sulfolane, and the lower phase is CO₂The lean phase, the main component is water. Only need to mix CO₂The enriched phase is sent to a desorption tower for regeneration, thereby solving the problem of overhigh desorption energy consumption of the existing non-phase-change system.

The technical scheme adopted by the invention is as follows: a liquid-liquid phase change absorbent for carbon dioxide capture, the absorbent is composed of primary amine, secondary amine, organic solvent and water, wherein the primary amine refers to Monoethanolamine (MEA), the secondary amine refers to 2- (ethylamino) ethanol (MAE), and the organic solvent refers to sulfolane.

The novel liquid-liquid phase change absorbent takes primary amine and secondary amine with high reaction activity as main absorbents, takes an aprotic polar organic solvent as a phase separation promoter, takes water as a solvent, and mixes the four components in different proportions to form CO capable of phase separation₂An absorbent. With conventional CO₂Compared with the absorbent, the problem of overhigh regeneration energy consumption is solved from the source.

The invention provides a liquid-liquid phase change absorbent for capturing carbon dioxide, which consists of primary absorbent primary amine (MEA), secondary amine (MAE), phase separation promoter sulfolane and solvent water, wherein the concentration of the primary absorbent is different from 1mol/L to 5mol/L, the concentration of the phase separation promoter is different from 3mol/L to 5mol/L, and the rest component is water. The composite absorbent contains high-activity primary amine and secondary amine, so high CO is ensured₂Absorption capacity and high reaction rate. The aprotic polar organic solvent and the polar aqueous solvent ensure that a phase transition occurs. The liquid-liquid phase change absorbent can absorb CO₂The principle of the post-occurrence phase separation can be represented by the attached FIG. 1: introducing CO into the solution₂Previously, sulfolane, amine and water were uniformly distributed in a homogeneous solution. In this case, since intramolecular bonds exist between both the amine molecules and the sulfolane molecules and the water molecules, the polarities of the solution can be harmonized to achieve a state of uniform equilibrium. Introducing CO into the sulfolane/amine solution₂After that, the amine solution absorbs CO₂Conversion to carbamates and protonated amines with formation of bicarbonate. At this time, ions in the solution undergo ionic hydration with water, which destroys the equilibrium homogeneous state of the solution. Due to sulfolane and amine-CO₂-H₂The polarity between O systems is completely different and the solution spontaneously changes to an immiscible emulsion state, then the droplets separate. Finally, the phase change of the solution is divided into liquid-liquid two phases.

After the phase separation of the absorbent, primary amine, secondary amine and CO₂The reaction products of (A) are mainly concentrated onPhase, therefore CO₂During regeneration, only the upper phase of the absorbent needs to be sent to the desorption tower, so that the energy consumption can be greatly reduced.

Further, the concentrations of the primary absorbents (MEA and EAE) in the phase change absorbents are different from 1mol/L to 5mol/L, and the concentrations of the phase separation promoter (sulfolane) are different from 3mol/L to 5 mol/L.

Further, the absorbent absorbs CO₂Then divided into two phases, the upper phase is CO₂Rich phase, enriching most secondary amines for absorbing CO₂And (4) obtaining the final product. The lower phase is CO₂The lean phase, the main component is water.

Further, CO₂The volume of the rich phase accounts for 30-80% of the total volume of the absorbent.

Further, CO for absorption₂The volume fraction of the gas is 5-20%, the absorption temperature is 30-50 ℃, and the absorption load is 0.40mol CO₂0.55mol CO per mol of amine₂Per mol of amine.

Further, the liquid-liquid phase change absorbent absorbs CO₂The rich phase is regenerated by high-temperature heating.

Further, the regeneration process conditions are: the regeneration temperature is 70-120 ℃, and the regeneration time is 30-120 min.

Another object of the present invention is to provide a liquid-liquid phase change absorbent for carbon dioxide capture in CO₂Application in the field of capture.

Further, the method comprises the following steps:

s1, taking the primary amine and the secondary amine as main absorbents, wherein the concentrations of the primary amine and the secondary amine are different from 1mol/L to 5mol/L, adding 3mol/L-5mol/L sulfolane as a phase separation promoter, and preparing a liquid-liquid phase change absorbent with a certain proportion by using the rest components as water;

s2, the phase change absorbent prepared by the S1 is used for absorbing CO needing to be purified₂5-20% flue gas or other mixed gas by volume fraction, and the absorption temperature is kept at 30-50 deg.C. Absorption of CO by liquid-liquid phase change absorbents₂Then divided into two phases, wherein the upper phase is CO₂The enriched phase is rich in most of primary amine and secondary amine such as carbamate and CO₂The reaction product of (1).

S3, phase change is generated after the liquid-liquid phase change absorbent passes through S2, the lower phase is separated from the upper phase and is sent to desorption regeneration, the temperature of desorption regeneration is 70-120 ℃, the regeneration time is 30-150 min, CO₂After release, is sent to the next station. Resulting regenerated CO₂Enriched phase and CO₂After mixing of the lean phase, the liquid-liquid phase change absorbent can be recovered for CO₂And (4) absorbing.

The invention has the beneficial effects that:

the invention selects primary amine and secondary amine as CO₂The main absorbent, non-proton polar sulfolane and high-polarity water are used as solvent to ensure that the absorbent absorbs CO₂The phase separation performance after the reaction is finished. CO of the absorbent₂Good absorption performance, rapid phase separation, excellent mass transfer performance and good regeneration stability. Compared with the conventional CO₂The absorbent greatly reduces the regeneration energy consumption and has wide application prospect.

Drawings

FIG. 1 shows that the phase change absorbent provided by the invention absorbs CO₂The mechanism of the later phase transition.

FIG. 2 is a diagram of an apparatus for an absorption experiment.

FIG. 3 is a graph showing the CO absorption of amine versus 5M/5M sulfolane/mixed amine at room temperature₂Influence of process phase separation. (a) Absorbing CO by sulfolane/mixed amine system solution under different mixture ratios₂The volume ratio of the upper phase to the lower phase; (b) absorbing CO by sulfolane/mixed amine system solution under different mixture ratios₂CO of upper and lower phases₂A load; (c) absorbing CO by sulfolane/mixed amine system solution under different mixture ratios₂The later amine concentration of upper and lower phases; (d) absorbing CO by sulfolane/mixed amine system solution under different mixture ratios₂The latter amine in the upper layer.

FIG. 4 is CO₂The absorption rate curves of the three systems, 5M/4M sulfolane/MEA, 5M/3M/2M sulfolane/MEA/EAE and 5M MEA, at a partial pressure of 15kPa and a temperature of 40 ℃ are plotted as a function of the CO2 load.

FIG. 5 shows desorption experiments for 5M MEA, 5M/4M sulfolane/MEA, and 5M/3M/2M sulfolane/MEA/EAE systems at 120 ℃. (a) Desorption rate curve as a function of CO₂A change in load; (b) CO2₂The variation of the load over time; (c) the variation of the average energy consumption value with time; (d) temperature and CO at the end of desorption₂The amount of desorption.

FIG. 6 is a diagram of an apparatus for desorption experiments.

Detailed Description

The liquid-liquid phase change absorbent and the use thereof according to the present invention will be described in detail with reference to examples. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. Other embodiments that are readily available based on the given embodiments are also within the scope of the invention.

Example 1

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 4mol/L, the concentration of the EAE is 1mol/L, and the concentration of the sulfolane is 5 mol/L.

The absorbent is used for absorbing CO₂The volume fraction of the simulated flue gas is 15%, the absorption temperature is 40 ℃, and the absorption time is 30 min. Absorption of CO by absorbent₂Upon reaching saturation, the absorbent separates into two phases, separating the CO₂Rich phase is separated and sent to desorption regeneration, the regeneration temperature is 120 ℃, and the regeneration time is 150 min.

Example 2

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 3mol/L, the concentration of the EAE is 2mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 3

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 2.5mol/L, the concentration of the EAE is 2.5mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 4

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 2mol/L, the concentration of the EAE is 3mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 5

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 1mol/L, the concentration of the EAE is 4mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 6

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 5mol/L, the concentration of the EAE is 0mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 7

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 4mol/L, the concentration of the EAE is 0mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 8

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 3mol/L, the concentration of the EAE is 1mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 9

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 2mol/L, the concentration of the EAE is 2mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Example 10

A liquid-liquid phase change absorbent for capturing carbon dioxide consists of a main absorbent MEA and an EAE, a phase separation promoter sulfolane and solvent water, wherein the concentration of the MEA is 1mol/L, the concentration of the EAE is 3mol/L, and the concentration of the sulfolane is 5 mol/L. The rest is the same as in example 1.

Comparative example 1

MEA was directly dissolved in water to prepare a 5mol/L aqueous MEA solution, and the absorption and desorption conditions were the same as in example 1.

Comparative example 2

In the absorbent, the concentration of MEA and sulfolane were 5mol/L and 4mol/L, respectively. The absorption and desorption conditions were the same as in example 1.

Experimental example 1

Measurement of CO absorption by the liquid-liquid phase Change absorbents of examples 1 to 6₂Volume ratio of two phases after phase separation, CO₂Equilibrium load, concentration of amine in two phases and CO₂Percentage of amine in the enriched phase.

The experimental method comprises the following steps: the CO shown in the attached figure 2 in the specification is adopted₂An absorbent apparatus, prepared according to the absorbent preparation method described in examples 1-6, was 25mL of absorbent, charged with a volume fraction of 15% CO₂Absorbing for half an hour at 40 ℃, and introducing infrared CO into the gas after absorption₂Analyzer constantly monitoring CO in gas₂The content of (a). And transferring the mixture into a measuring cylinder after absorption, standing and layering the mixture, and measuring the volume ratio of the upper phase to the lower phase. CO2₂Balancing load and CO₂The percentage content in the enriched phase was determined by titration.

The results are shown in FIG. 3 of the specification, and FIG. 3 depicts the liquid-liquid phase change absorbent absorptions of examples 1-6CO₂Volume ratio of two phases after phase separation, CO₂Equilibrium load, concentration of amine in two phases and CO₂Percentage of amine in the enriched phase. It can be seen that the absorbents of examples 1-6 are absorbing CO₂Phase changes occur after half an hour. It can be found that (1) when the sulfolane/mixed amine ratio is fixed, the volume ratio of the upper solution shows a gradually increasing trend along with the increase of the initial concentration ratio of EAE; in contrast, as the initial concentration ratio of MEA increases, the volume ratio of the upper layer solution decreases. (2) The load difference of the upper solution of sulfolane/MEA/EAE system solutions with different mixture ratios is not large, and is about 0.47mol/mol CO₂The lower phase solution is loaded lower than the upper phase solution; (3) when the sulfolane/mixed amine ratio is fixed, the amine concentration of the upper-layer solution is continuously reduced and the amine concentration of the lower-layer solution is continuously increased along with the increase of the initial concentration ratio of the EAE, so that the amine ratio of the upper-layer solution is also indirectly reduced. When the MEA/EAE ratio is less than 2/3, the amine concentration and amine ratio of the upper layer solution show a tendency to decrease rapidly;

the reason for the above is mainly that sulfolane is not phase-changed with EAE system solution, and is mixed with MEA to form phase-change system, in sulfolane/MEA/EAE system, absorbing CO₂The product of the post-MEA is more polar, changing the polarity of the solution, amine-CO₂-H₂The difference between the polarity of O system and sulfolane is increased, so that the phase change delamination phenomenon occurs, more amine molecules are left in the upper layer, and sulfolane is left in the lower layer. Thus, the higher the MEA concentration ratio, the more distinct the solution stratifies, and the higher the amine ratio and amine concentration of the upper solution, eventually approaching the level of the sulfolane/MEA system solution. And because of the hydrophobic nature of sulfolane in the lower phase, it is less attractive to carbamates and bicarbonate and therefore will decompose less CO₂Resulting in lower CO₂And (4) loading.

Experimental example 2

Measurement of CO absorption by liquid-liquid phase Change absorbents of example 2 and comparative examples 1 to 2₂The absorption rate of (c). The experimental method was the same as in experimental example 1.

The results are shown in FIG. 4 of the specification, and FIG. 4 depicts the absorption rates of example 2 and comparative examples 1-2Curve with load. The magnitude of the absorption rates for the three systems can be found to be ordered: 5M MEA > 5M/3M/2M sulfolane/MEA/EAE > 5M/4M sulfolane/MEA. Wherein the absorption rate and CO of the pure amine solution₂The load is much higher than that of the two-phase change system solution, because the pure amine solution has higher water content and amine content, and the amine solution is mixed with CO₂Carbamate generated by the reaction is easier to hydrate to generate bicarbonate radical, and CO in an absorption experiment is improved₂And (4) loading. And because the concentration of the pure amine solution is lower than that of the phase-change solution, the liquid viscosity is lower, the mass transfer property and the fluidity are better, and the method is beneficial to CO₂Sufficient contact and reaction with the solution and therefore a high absorption rate.

Experimental example 3

Measurement of CO absorption by liquid-liquid phase Change absorbents of example 2 and comparative examples 1 to 2₂After phase separation, CO₂Desorption rate of rich phase, desorption energy consumption and CO₂The amount of desorption.

The experimental method comprises the following steps: the absorbent absorption steps described in Experimental example 2 and comparative examples 1-2 were repeated to obtain an absorbent reaching the end of absorption, using CO as shown in FIG. 6 of the specification₂The reproducing device records the power consumption by the electric energy meter and records the time by the timer. CO desorbed from the rich amine solution₂The gas is cooled by a condenser pipe and then flows out, and then N is used₂Dilution of the CO at the outlet by the gas stream₂Gas, flowing the diluted gas into CO₂Infrared sensor to measure CO₂And (4) concentration.

The results are shown in FIG. 5 of the specification, and FIG. 5 depicts the liquid-liquid phase change absorbents, CO, of example 2 and comparative examples 1-2₂Desorption rate of rich phase, desorption energy consumption and CO₂The amount of desorption.

TABLE 15M MEA, 5M/4M sulfolane/MEA and 5M/3M/2M sulfolane/MEA/EAE systems desorption energy consumption values, desorption end point temperature and CO₂Amount of desorption

As can be seen in FIG. 5a, the 5M/4M ringThe desorption rates for the tetramethylene sulfone/MEA and 5M/3M/2M sulfolane/MEA/EAE systems are much greater than for the 5M MEA solution because the phase change system only needs to separate the upper solution for desorption. The upper solution after the phase change of the solution has high amine concentration, low water content and CO₂And is more easily desorbed from the solution. Since the total concentration of the 5M/3M/2M sulfolane/MEA/EAE system was higher than the 5M/4M sulfolane/MEA system, the desorption rates for the three systems were ranked in magnitude: 5M/3M/2M sulfolane/MEA/EAE > 5M/4M sulfolane/MEA > 5M MEA. This is in contrast to the desorption of CO for the systems in FIG. 5b₂The load is consistent with the change over time. CO of 5M/3M/2M sulfolane/MEA/EAE System₂The load is increased and decreased with time at the fastest speed, the load is 5M/4M sulfolane/MEA system is the second, and the CO of the 5M MEA system₂The load drops slowest. It can be seen from fig. 5c that the 5M MEA system has higher energy consumption for desorption than the 5M/4M sulfolane/MEA and the 5M/3M/2M system, due to the higher solution concentration and the higher azeotropic point in the phase change system. From Table 1 and FIG. 5d, it can be seen that in the desorption experiment of the three systems, CO of the 5M MEA system₂The desorption amount is high, and the amount is two sulfolane-based phase change solution systems. The 5M/3M/2M sulfolane/MEA/EAE system has a CO2 desorption amount of 0.9332mol, which is 18.8% higher than that of the 5M/4M sulfolane/MEA system and is only 4.1% lower than that of the 5M MEA. The desorption energy consumption of the three systems is ordered as follows: 5M MEA > 5M/4M sulfolane/MEA > 5M/3M/2M sulfolane/MEA/EAE, CO₂The desorption amount is ordered as follows: 5M MEA > 5M/3M/2M sulfolane/MEA/EAE > 5M/4M sulfolane/MEA.

Combining the above analysis, the 5M/3M/2M sulfolane/MEA/EAE system has good absorption and desorption performances compared with the traditional absorbent, and has great practical significance in industry as a sulfolane-based phase variant system.

The above description is only a few embodiments of the present invention, and is not intended to be used in the protection scope of the present invention. Any modification, equivalent replacement, improvement and the like, which are within the spirit and principle of the present invention, are included in the protection scope of the present invention.