Application of amino-terminated 0-generation polyamide-amine dendritic polymer as carbon dioxide absorbent

Abstract

The invention relates to the technical field of carbon dioxide capture, in particular to application of an amino-terminated 0-generation polyamide-amine dendritic polymer as a carbon dioxide absorbent. The amino-terminated 0-generation polyamide-amine dendritic polymer is a polyamide-amine dendritic polymer which takes amino as an end group and alkylene diamine as a core, and the algebra G is 0. The amino-terminated 0-generation polyamide-amine dendritic polymer structurally contains four amino-terminated primary amino groups, and when the amino-terminated 0-generation polyamide-amine dendritic polymer is used as a carbon dioxide absorbing agent, compared with an existing traditional organic amine absorbing agent, the amino-terminated 0-generation polyamide-amine dendritic polymer has relatively high absorbing capacity and relatively high absorbing rate; the carbon dioxide desorption and absorbent regeneration capacities are relatively high, and the circulating absorption capacity is relatively high; the cycling stability is relatively high, and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, separation or recovery, and in particular to the application of amino-terminated 0-generation polyamide-amine dendritic polymer as a carbon dioxide absorbent. Background Art

[0002] In recent years, CO2 caused by human activities has 2 The increasing emissions have led to a more serious global warming problem. The extreme climate phenomena caused by this have become increasingly hot, seriously affecting the quality of human life and sustainable development. As the world's main energy source, fossil fuels such as coal, oil and natural gas emit CO 2 Global energy-related CO 2 Emissions have increased rapidly from 9.4 billion tons in 1960 to 37.4 billion tons in 2023, and the amount of CO in the atmosphere has increased significantly. 2 The content has increased from 316 ppm in 1960 to 419 ppm in 2023. In order to effectively curb global warming, CO 2 Effectively capture and resolve CO 2 Recycling issues.

[0003] Currently, CO can be achieved in the short term 2 The mainstream technology route for emission reduction is CO 2 Capture, utilization and storage (CCUS) technology, in which the first step is CO 2 Capture is the premise and basis for realizing this technology. 2 The capture methods include pre-combustion capture, combustion capture and post-combustion capture. Pre-combustion capture mainly includes integrated coal gasification gas-steam combined cycle (IGCC); combustion capture includes oxygen-enriched combustion technology and chemical continuous combustion technology; post-combustion capture technology does not require changes to the incineration system, only the addition of CO 2 The capture device requires the least modification to the power plant, has low initial investment and relatively mature technology, and is currently the most economical and applicable technology.

[0004] Post-combustion CO capture 2 The technologies mainly include chemical absorption, physical absorption, physical adsorption, membrane separation, cryogenic separation, etc. Among them, chemical absorption technology has a long history, mature technology, stable operation, and has commercial operation and demonstration platforms. Chemical absorption technology is to use chemical absorbent solution and CO 2 The chemical reaction between CO 2Chemical absorbents mainly include alkaline substances such as ammonia, potassium carbonate / sodium salt, and organic amines. The ammonia absorption method requires low temperature and a large amount of water washing or even acid washing to inhibit volatility because ammonia is volatile, resulting in high operating costs. The potassium carbonate / sodium salt absorption method, also known as the hot potassium / sodium alkali method, has a slow absorption rate and generally operates at a higher temperature, which is suitable for high CO 2 The partial pressure of gas is used to determine the CO content of flue gas from coal-fired power plants and gas-fired power plants. 2 The capture effect is poor; the organic amine absorption method has the advantages of fast absorption rate, relatively simple operation and maintenance, and low cost, and is suitable for CO 2 In places with low concentration / partial pressure, such as coal-fired power plants, cement plants, steel plants, etc., the flue gas is mostly discharged after dust removal, desulfurization and denitrification, which has CO 2 Due to the low concentration / partial pressure characteristics, the organic amine absorption method is suitable.

[0005] Organic amine absorption method to capture CO 2 Appeared in 1930 (US 1783901), it has a history of more than 90 years. The principle is to use the aqueous solution of organic amine as the absorption medium, enter the absorption tower, and react with CO in the mixed gas at a low temperature of 40~50℃. 2 Absorption reaction occurs, CO 2 Absorbed to form CO 2 The rich liquid with high concentration then enters the desorption tower and generates CO at a high temperature of 100~130℃ 2 The desorption reaction is carried out, and at the same time, the organic amine is regenerated to form a product containing no or a small amount of CO 2 The lean liquid is circulated to absorb CO 2 , the released CO 2 Collect and use them.

[0006] Can do CO 2 There are many types of organic amines as absorbents. According to the number of hydrocarbon groups connected to the nitrogen atom, organic amines can be divided into primary amines, secondary amines, and tertiary amines. According to the number of amino groups, organic amines can be divided into monoamines, diamines, linear polyamines, and cyclic polyamines.

[0007] Typical monoamines include primary amines, such as monoethanolamine (MEA), 2-amino-2-methyl-propanol (AMP), etc.; secondary amines, such as diethanolamine (DEA), N-methylethanolamine (MMEA), etc.; tertiary amines, such as triethanolamine (TEA), N-methyldiethanolamine (MDEA), etc.

[0008] Typical diamines include ethylenediamine (EDA), butanediamine (BDA), hexamethylenediamine (HDA), etc.

[0009] Typical linear polyamines include diethylenetriamine (DETA), triethylenetetramine (TETA), etc.

[0010] Typical cyclic polyamines include piperazine (PZ), N-methylpiperazine (MPZ), etc. Among the above-mentioned traditional organic amine absorbents, primary amines (such as monoethanolamine, MEA) and secondary amines (such as diethanolamine, DEA) have faster CO 2 absorption rate; however, the desorption temperature is high and the regeneration energy consumption is high; the desorption rate is low and the cycle capacity is low; at the same time, the high desorption temperature and long desorption time also mean that there is a large amount of solvent volatilization, which makes the organic amine loss higher and the cycle stability poorer.

[0011] Tertiary amine absorbents, such as N-methyldiethanolamine (MDEA), are used in CO 2 Compared with primary and secondary amines, the desorption rate is higher during the desorption process, but its absorption of CO 2 The rate is much lower than that of primary and secondary amines, resulting in lower absorption capacity and circulation capacity.

[0012] Diamines (such as EDA) and linear polyamines (such as DETA, TETA, TEPA, etc.), although CO 2 The absorption capacity is high, but the desorption temperature is high and the desorption rate is not high, resulting in high regeneration energy consumption and limited circulation capacity; and this type of amine usually has a strong ammonia odor and is highly volatile, and the desorption process is prone to secondary pollution; the amine loss is also large and the circulation stability is not high.

[0013] Cyclic polyamines, such as piperazine (PZ), are cyclic diamines that were first added as activators to conventional MEA, MDEA, and AMP solutions to increase CO 2 Absorption rate. Piperazine has the advantages of less loss during use and strong cycle stability due to its lack of ammonia odor and low volatility. However, its disadvantages are high desorption temperature, low desorption rate, high regeneration energy consumption, limited solubility, and easy crystallization at high concentrations or low temperatures.

[0014] In order to achieve CO 2 In order to achieve the purpose of fast absorption and desorption, mixed amines are often used, such as MEA and MDEA, EDA and AMP, PZ and AMP, etc. However, due to the differences in boiling points, volatility, and thermal degradation efficiency of each component of the mixed amine, the ratio of the two will change after multiple cycles of use, thus affecting its performance effect. In addition, the cyclic stability of the mixed amines has not been improved.

[0015] Therefore, the existing traditional organic amines cannot meet the requirements of CO 2 The field of carbon neutrality in capture requires high-efficiency absorbents with fast absorption rate, high absorption capacity, high desorption rate and strong cyclic absorption stability. Summary of the invention

[0016] In order to solve the above technical problems, the present invention provides an amino-terminated 0-generation polyamide-amine dendritic polymer for use as a carbon dioxide absorbent. 2 The application of the absorbent, the amino-terminated 0-generation polyamide-amine dendritic polymer is a polyamide-amine dendritic polymer with amino groups as terminal groups, alkylenediamine as core, and generation G as 0. In the present invention, the structural formula of the amino-terminated 0-generation polyamide-amine dendritic polymer is: , Wherein, n is a positive integer between 1 and 12.

[0017] The polyamidoamine (PAMAM) is a dendritic polymer that was first successfully synthesized by Tomalia of DOW Chemical Company in 1985 and commercialized in 1990. Due to its highly branched and radially symmetrical unique structural characteristics, it is widely used in biopharmaceutical sustained release, genetic material carriers, surfactants, environmental pollutant flocculation treatment, etc.

[0018] The inventors have found that amino-terminated 0-generation polyamidoamine dendritic polymers can be used as CO 2 New application field of absorbent, the amino-terminated 0-generation polyamidoamine dendrimer absorbs CO 2 The resulting carbamate-terminated 0-generation polyamide-amine dendrimer has a high carbon dioxide desorption capacity and a regeneration capacity of the 0-generation polyamide-amine dendrimer. It also has the advantages of high cycle absorption capacity and high cycle stability. It can be used for CO in mixed gases. 2 capture, separation or recovery.

[0019] In the present invention, the amino-terminated polyamide-amine dendritic polymer is used as CO 2 The absorbent is applied as follows: The amino-terminated 0-generation polyamide-amine dendritic polymer is mixed with water to obtain CO 2 absorbent solution; The CO 2 Absorbent solution and CO 2 The mixed gas contacts and absorbs to obtain CO 2 heating the absorption rich liquid containing CO 2 The absorbed rich liquid undergoes a desorption reaction, releasing CO 2 , while CO 2 The absorbent solution is regenerated, and after regeneration, CO 2 The absorbent solution is the desorption lean solution; the released CO is collected 2, desorption lean liquid is recycled for CO 2 The next round of absorption.

[0020] In the present invention, CO 2 The concentration of the amino-terminated 0-generation polyamidoamine dendrimer in the absorbent solution is 10-60wt%, and the rest is water.

[0021] In the present invention, the absorption reaction temperature is 0°C to 60°C, and the absorption reaction time is 0.5 to 3 h.

[0022] In the present invention, the temperature of the desorption reaction is 90° C. to 130° C., and the heating desorption time is 0.5 to 3 hours.

[0023] In the present invention, CO 2 CO in the mixed gas 2 The volume fraction is 1~99%.

[0024] The amino-terminated 0-generation polyamide-amine dendritic polymer of the present invention is used as CO 2 Absorbent for CO in mixed gas 2 It has the following advantages in capture and separation: (1) high absorption capacity and fast speed; (2) high desorption efficiency after absorbing carbon dioxide; (3) low volatility, less loss during high-temperature regeneration, and strong cyclic absorption stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The CO of the absorbent solution of the amino-terminated 0-generation polyamidoamine dendrimer of Examples 1 to 4 and the conventional organic amine of Comparative Examples 1 to 3 is 2 Curve of absorption load changing with time; Figure 2 The CO concentration of the amino-terminated 0-generation polyamidoamine dendrimers of Examples 1 to 4 and the conventional organic amines of Comparative Examples 1 to 3 at an oil bath temperature of 120°C is 2 Desorption rate; Figure 3 CO in Example 1 and Comparative Examples 1 to 3 in the first absorption-desorption cycle 2 Variation of load over time; Figure 4 The CO of Example 1 and Comparative Examples 1 to 3 during multiple cycles of absorption-desorption 2 Changes in absorption capacity. DETAILED DESCRIPTION

[0026] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below through specific embodiments in combination with the accompanying drawings, but the embodiments should not be construed as limiting the present invention.

[0027] The present invention is achieved in the following ways: In the present invention, the structural formula of the amino-terminated 0-generation polyamide-amine dendrimer is as follows: , wherein n is a positive integer between 1 and 12. For example, it can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] In the present invention, the amino-terminated polyamide-amine dendrimer is used for CO in the mixed gas. 2 capture, separation or recovery.

[0029] In the present invention, CO 2 The concentration of the amino-terminated 0-generation polyamide-amine dendritic polymer in the absorbent is 10-60wt%, and illustratively, it can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, etc., or any interval between any two values. In a specific embodiment of the present invention, the amino-terminated 0-generation polyamide-amine dendritic polymer is used as CO 2 The application method of the absorbent is as follows: the amino-terminated 0-generation polyamide-amine dendritic polymer is mixed with water to obtain CO 2 absorbent solution; The CO 2 Absorbent solution and CO 2 The mixed gas contacts and absorbs to obtain CO 2 heating the absorption rich liquid containing CO 2 The absorbed rich liquid undergoes a desorption reaction, releasing CO 2 , while CO 2 The absorbent solution is regenerated, and the regenerated CO 2 The absorbent solution is the desorption lean solution; the released CO is collected 2 , desorption lean liquid is recycled for CO 2 The next round of absorption.

[0030] In the present invention, the temperature of the absorption reaction is 0°C to 60°C, and the absorption reaction time is 0.5 to 3 h. For example, the temperature can be 0, 10, 20, 30, 40, 50, 60°C, etc., or any interval between any two values; the reaction time can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, etc., or any interval between any two values.

[0031] In the present invention, the temperature of the desorption reaction is 90°C~130°C, and illustratively, it can be 90°C, 100°C, 110°C, 120°C, 130°C, etc., or any interval value between two arbitrary numerical values; the time of the desorption reaction is 0.5~3h, and illustratively, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, etc., or any interval value between any two numerical values.

[0032] In the present invention, CO 2 CO in the mixed gas 2 The volume fraction is 1-99%. For example, it can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., or 10-50%, 50%-60%, 50%-70%, 50%-80%, 50%-99%, etc.; or any interval value between any two values.

[0033] The amino-terminated, alkylene-core 0-generation polyamide-amines used in Examples 1 to 4 of the present invention are commercially available products, all of which are 20% methanol solutions.

[0034] The monoethanolamine, ethylenediamine and triethylenetetramine used in the comparative examples of the present invention are all from Sinopharm Chemical Reagent Co., Ltd.

[0035] Example 1: 0-generation polyamide-amine with amino-terminated and ethylenediamine core Preparation process of absorbent solution: 375.0 g of a methanol solution of amino-terminated, ethylenediamine core 0 generation polyamide-amine (PAMAM Dendrimer, 1,2-Ethylenediamine Core, Generation 0.0, abbreviated as PAMAM-EDA-0G in the present invention) with an effective content of 20% is subjected to reduced pressure distillation to remove methanol at a condition of less than 50° C. using a vacuum rotary evaporator to obtain about 75.0 g of viscous PAMAM-EDA-0G; then 175.0 g of deionized water is added and stirred evenly to obtain 250.0 g of amino-terminated, ethylenediamine core 0 generation polyamide-amine absorbent solution (30 wt% PAMAM-EDA-0G) with a solid content of 30.0 wt%.

[0036] The prepared absorbent solution was subjected to performance test according to the test example.

[0037] The chemical formula of the 0-generation polyamide-amine (PAMAM-EDA-0G) dendritic polymer with terminal amino groups and ethylenediamine core is (CH 2 ) 2 [N(CH 2 CH 2 CONHCH 2 CH 2 NH2 ) 2 ] 2 , the structural formula is: .

[0038] Example 2: Generation 0 polyamide-amine with amino-terminated and propylene diamine core Preparation process of absorbent solution: 375.0 g of methanol solution of amino-terminated, propylenediamine core 0 generation polyamide-amine (PAMAM Dendrimer, 1,2- Propylenediamine Core, Generation 0.0, abbreviated as PAMAM-PDA-0G in the present invention) with an effective content of 20% is subjected to reduced pressure distillation to remove methanol at a condition of less than 50° C. using a vacuum rotary evaporator to obtain about 75.0 g of viscous PAMAM-PDA-0G; then 175.0 g of deionized water is added and stirred evenly to obtain 250.0 g of amino-terminated, propylenediamine core 0 generation polyamide-amine absorbent solution (30 wt% PAMAM-PDA-0G) with a solid content of 30.0 wt%.

[0039] The prepared absorbent solution was subjected to performance test according to the test example.

[0040] The chemical formula of the 0-generation polyamide-amine (PAMAM-PDA-0G) dendritic polymer with terminal amino groups and propylene diamine core is (CH 2 ) 3 [N(CH 2 CH 2 CONHCH 2 CH 2 NH 2 ) 2 ] 2 , the structural formula is: .

[0041] Example 3 Preparation process of amino-terminated, hexamethylenediamine core 0th generation polyamide-amine absorbent solution: 375.0 g of a methanol solution of amino-terminated, hexamethylenediamine core (PAMAM Dendrimer, 1,2-Hexamethylenediamine Core, Generation 0.0, abbreviated as PAMAM-HDA-0G in the present invention) with an effective content of 20% was subjected to reduced pressure distillation to remove methanol at a temperature less than 50° C. using a vacuum rotary evaporator to obtain about 75.0 g of viscous PAMAM-HDA-0G; then 175.0 g of deionized water was added and stirred evenly to obtain 250.0 g of amino-terminated, hexamethylenediamine core 0th generation polyamide-amine absorbent solution (30 wt% PAMAM-HDA-0G) with a solid content of 30.0 wt%.

[0042] The prepared absorbent solution was subjected to performance test according to the test example.

[0043] The chemical formula of the 0-generation polyamide-amine (PAMAM-HDA-0G) dendritic polymer with terminal amino groups and hexamethylenediamine core is (CH 2 ) 6 [N(CH 2 CH 2 CONHCH 2 CH 2 NH 2 ) 2 ] 2 , the structural formula is: .

[0044] Example 4: 0-generation polyamide-amine with amino group terminal and dodecanediamine core Preparation process of absorbent solution: 375.0 g of a methanol solution of PAMAM Dendrimer, 1,2-Dodecamethylenediamine Core, Generation 0.0 (PAMAM-DDA-0G in the present invention) with an effective content of 20% is subjected to reduced pressure distillation to remove methanol at a temperature less than 50° C. using a vacuum rotary evaporator to obtain about 75.0 g of viscous PAMAM-DDA-0G; then 175.0 g of deionized water is added and stirred evenly to obtain 250.0 g of a 0-generation polyamide-amine absorbent solution (30 wt% PAMAM-DDA-0G) with a solid content of 30.0 wt%.

[0045] The prepared absorbent solution was subjected to performance test according to the test example.

[0046] The chemical formula of the 0-generation polyamide-amine (PAMAM-DDA-0G) dendritic polymer with terminal amino groups and a dodecanediamine core is (CH 2 ) 12 [N(CH 2 CH 2 CONHCH 2 CH 2 NH 2 ) 2 ] 2 , the structural formula is: .

[0047] Comparative Example 1 Monoethanolamine Preparation process of absorbent solution: prepare 250.0 g of 30.0 wt% monoethanolamine (MEA) solution, including 75.0 g of MEA and 175.0 g of deionized water.

[0048] The prepared absorbent solution was subjected to performance test according to the test example.

[0049] Comparative Example 2 Ethylenediamine Preparation process of absorbent solution: prepare 250.0 g of 30.0 wt% ethylenediamine (EDA) solution, including 75.0 g of TETA and 175.0 g of deionized water.

[0050] The prepared absorbent solution was subjected to performance test according to the test example.

[0051] Comparative Example 3 Triethylenetetramine Preparation process of absorbent solution: prepare 250.0 g of 30.0 wt% triethylenetetramine (TETA) solution, including 75.0 g of TETA and 175.0 g of deionized water.

[0052] The prepared absorbent solution was subjected to performance test according to the test example.

[0053] Test Example 1 Absorption capacity test 250.0 g, 30.0 wt% of the organic amine absorbent solutions of Examples 1 to 4 and Comparative Examples 1 to 3 were added to a round-bottom flask placed in an oil bath. The oil bath temperature was controlled at 40° C. and CO was introduced. 2 CO with a volume fraction of 15% 2 and N 2 Mixed gas, mixed gas flow rate 2200 mL / min, pressure 0.1 MPa, sampling every 10 minutes, the CO of the absorption liquid was determined by acid hydrolysis gas method 2 Load, until CO 2 Until the absorption load does not change, the CO 2 Absorption of rich liquid.

[0054] Each CO 2 Absorption of CO in rich liquid 2 The load changes with time Figure 1 As shown, it can be seen that the absorption performance of the amino-terminated 0-generation polyamide-amine solutions of Examples 1 to 4 is basically the same. The absorbent solutions of Examples 1 to 4 reach saturated absorption after 1000 min, and Comparative Example 1, Comparative Example 2, and Comparative Example 3 reach saturated absorption at 120 min, 150 min, and 150 min, respectively. The saturated absorption capacity is shown in Table 1, and the maximum absorption capacity is as follows: Examples 1 to 4 (PAMAM-0G) > Comparative Example 3 (TETA) > Comparative Example 2 (EDA) > Comparative Example 1 (MEA).

[0055] The 0-generation polyamide-amine dendrimer (PAMAM-0G) in Examples 1 to 4 of the present invention contains four terminal primary amino groups, and the triethylenetetramine (TETA) in Comparative Example 3 contains two primary amino groups and two secondary amino groups. Although PAMAM-0G and TETA are both tetramines, the CO 2 The absorption capacity is significantly higher than that of TETA in Comparative Example 3; the absorption capacity of tetraamine TETA on CO 2 The absorption capacity of PAMAM-0G of the present invention is higher than that of diamine EDA; diamine EDA is higher than that of monoamine MEA; thus, the absorption capacity of PAMAM-0G of the present invention is higher than that of diamine EDA; 2 The absorption has the maximum absorption capacity.

[0056] Table 1 CO absorbed by each absorbent 2 Saturated absorption capacity

[0057] Test Example 2 Desorption performance test Place the desorption bottle with a reflux condenser in an oil bath heater and heat it to a certain temperature. Place the absorbed rich liquid of the absorbent obtained in Test Example 1 in the desorption bottle. Take samples at regular intervals and determine the CO 2 Load, waiting for CO 2 If there is no obvious change in load, desorption is complete, and the desorbed CO 2 The gas is vented to obtain the regenerated desorption liquid, which is the desorption lean liquid.

[0058] Desorption rate calculation: CO 2 Desorption rate (%) = (CO absorbed by rich liquid 2 Load - desorption of CO from lean solution 2 load) / (rich liquid CO 2 Load)100%.

[0059] When the oil bath temperature is 120 °C, the CO of each rich absorption liquid 2 The change of desorption rate with time is as Figure 2 shown. The results show that the desorption rate increases with the extension of heating time; the desorption rates of the 0-generation polyamide-amine dendrimer of Examples 1 to 4 of the present invention for CO 2 are basically the same, indicating that the structure of the internal core of the 0-generation polyamide-amine dendrimer (PAMAM-0G) of the present invention has little effect on its desorption performance. The desorption rates of the rich absorption liquids of Examples 1 to 4 of the present invention are fast, reaching more than 80% after 60 min, then increasing slowly, and no longer changing after 160 min. Their maximum desorption rates are 92.15%, 92.44%, 92.89%, 91.68%, and 91.40% respectively; while the desorption rates of the rich absorption liquids of MEA in Comparative Example 1, EDA in Comparative Example 2, and TETA in Comparative Example 3 are relatively low, and basically no longer change after 150 min. Their maximum desorption rates are 71.13%, 52.32%, and 63.27% respectively.

[0060] At the oil bath temperature of 120 °C, the maximum cycle capacity and the regeneration rate of the absorbent of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 2. Among them, the maximum cycle capacity is the difference between the CO 2 load of the rich absorption liquid at saturated absorption and the CO 2 load of the lean desorption liquid when desorption is complete; the regeneration rate is the percentage of the maximum cycle capacity to the CO 2 load of the rich liquid at saturated absorption. The regeneration rate value is the same as the desorption rate. It can be seen from Table 2 that the terminal amino 0-generation polyamide-amine dendrimer of the present invention has a good cycle absorption capacity. It absorbs CO 2 , and the regeneration rate of the absorbent can reach about 92%, while the regeneration rates of the traditional organic amine absorbents MEA, EDA, and TETA are relatively low.

[0061] Therefore, the terminal amino 0-generation polyamide-amine dendrimer of the present invention has good desorption CO 2 performance and absorbent regeneration performance.

[0062] Table 2 Maximum cycle capacity and maximum desorption rate of each absorbent solution at the oil bath temperature of 120 °C 2 Maximum desorption rate

[0063] Test Example 3 Influence of temperature on desorption rate As Figure 2 can be seen, the structure of the internal core of the 0-generation polyamide-amine dendrimer (PAMAM-0G) of the present invention has little effect on its desorption performance. Therefore, the influence of desorption temperature on the desorption rate is described below taking Example 1 as an example.

[0064] The absorbed rich solution obtained in Test Example 1 was placed in a desorption bottle. When the oil bath temperature was 110°C, 120°C, and 130°C, the CO 2 The desorption rate is shown in Table 3. The results show that the desorption capacity increases with the increase of desorption temperature and the extension of desorption time. Under the oil bath stability of 130°C, after the absorption rich liquid of Example 1 is heated for 180 min, its desorption capacity of CO 2 The desorption rate reached 100%, and the absorbent was completely regenerated; under the same conditions, the desorption rates of MEA, EDA, and TETA in Comparative Examples 1 to 3 were 75.56%, 59.34%, and 73.12%, respectively, which further illustrates that the amino-terminated 0-generation polyamidoamine dendritic polymer of the present invention has extremely excellent CO 2 Desorption capacity.

[0065] Table 3 Desorption rate of absorbed rich liquid at different oil bath temperatures

[0066] Test Example 4 Stability of Cyclic Absorption Capacity 30 wt% of CO from Examples 1 to 4 and Comparative Examples 1 to 3 2 250.00 g of absorbent solution were added into the absorption bottle and CO was introduced at 40 °C. 2 CO with a volume fraction of 15% 2 and N 2 The mixed gas was absorbed at a flow rate of 2200 mL / min and a pressure of 0.1 MPa. After absorbing for 120 min, the gas containing CO 2 Absorption of rich liquid.

[0067] Then, the absorbed rich liquid was desorbed at an oil bath temperature of 120°C for 120 min to obtain a desorbed lean liquid. The desorbed lean liquid was subjected to the next round of absorption to obtain an absorbed rich liquid. The absorbed rich liquid was desorbed again to obtain a desorbed lean liquid. This cycle was repeated several times, and the CO content of the solution was measured at the same time. 2 load, calculate cycle capacity and regeneration rate.

[0068] CO in the first absorption-desorption cycle 2 The load changes over time are shown in Figure 3 shown.

[0069] The comparison between the regeneration rate and circulation capacity of the absorbent solution in the first cycle and the maximum regeneration rate and maximum circulation capacity of the absorbent solution is shown in Table 4.

[0070] The circulating absorption capacity is CO 2 Load and lean liquid CO 2 The regeneration rate is the circulating absorption capacity as a percentage of the rich liquid CO2 The percentage of the load, the absorbent regeneration rate, and the CO desorption rate of the rich liquid 2 have the same value.

[0071] Table 4 Regeneration rate and cycle capacity of the absorbent solution in the first round (120 °C)

[0072] From Figure 3 and Table 2, it can be seen that the regeneration rate of PAMAM-EDA-0G of the present invention can reach 91.24% after 120 minutes of desorption, and the cycle capacity is relatively large; while the regeneration rates of MEA, EDA, and TETA in the comparative examples are 69.02%, 50.58%, and 63.21% respectively at 120 minutes, and the regeneration rates are relatively low, carrying more CO 2 load and entering a new round of absorption-desorption cycle.

[0073] During multiple cycles, the changes in the CO absorption capacity of the absorbent solutions of Example 1 and Comparative Examples 1-3 2 are shown in Figure 4 . Since the regeneration rate of the absorbent solution of PAMAM-EDA-0G in Example 1 of the present invention is 91.24%, the absorption capacity in the second round of cycle is 91.24% of that in the first round of absorption, dropping to 1.985 mol CO 2 / mol. However, after 9 cycles, the absorption capacity is 1.961 mol CO 2 / mol, and the attenuation is extremely slow, and the cyclic absorption stability is strong; while for MEA, EDA, and TETA, due to the relatively low regeneration rate, the absorption capacity in the second round of cycle is less than that in the first round, and the cyclic absorption capacities in the 3rd to 10th cycles gradually decay, among which EDA decays the fastest and MEA follows.

[0074] Obviously, the above examples are only for illustration and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An application of an amino-terminated 0-generation polyamide-amine dendritic polymer as a CO2 absorbent, wherein the amino-terminated 0-generation polyamide-amine dendritic polymer is a polyamide-amine dendritic polymer with an amino group as the end group, an alkylenediamine as the core, and a generation number G of 0.

2. The use according to claim 1, characterized in that: The structural formula of the amino-terminated 0-generation polyamide-amine dendrimer is: ， Wherein, n is a positive integer between 1 and 12.

3. The use according to claim 1, characterized in that: The amino-terminated 0-generation polyamide-amine dendrimer is used as a CO2 absorbent and is applied to the capture, separation or recovery of CO2 in a mixed gas.

4. The use according to any one of claims 1 to 3, characterized in that: The application method of the amino-terminated 0-generation polyamide-amine dendritic polymer as a CO2 absorbent is as follows: Mixing the amino-terminated 0-generation polyamide-amine dendritic polymer with water to obtain a CO2 absorbent solution; The CO2 absorbent solution is contacted with a mixed gas containing CO2 to cause an absorption reaction, thereby obtaining an absorption rich liquid containing CO2; the absorption rich liquid containing CO2 is heated to cause a desorption reaction, thereby releasing CO2, and at the same time, the CO2 absorbent solution is regenerated, and the regenerated CO2 absorbent solution is the desorption lean liquid; the released CO2 is collected, and the desorption lean liquid is recycled for the next round of CO2 absorption.

5. The use according to claim 4, characterized in that: The concentration of the amino-terminated 0-generation polyamidoamine dendrimer in the CO2 absorbent solution is 10-60 wt%.

6. The use according to claim 4, characterized in that: The temperature of the absorption reaction is 0°C to 60°C, and the time of the absorption reaction is 0.5 to 3 h.

7. The use according to claim 4, characterized in that: The temperature of the desorption reaction is 90° C. to 130° C., and the time of the desorption reaction is 0.5 to 3 hours.

8. The use according to claim 1, characterized in that: The volume fraction of CO2 in the mixed gas containing CO2 is 1~99%.

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