A supported catalyst, its preparation method and application, and a method for regenerating organic amine solutions.

Abstract

The present invention belongs to the technical field of carbon dioxide capture, and specifically relates to a supported catalyst, a preparation method and application thereof, and a method for regenerating an organic amine solution. The supported catalyst provided by the present invention comprises γ-Al2O3 and Zr and M metals supported on the surface and in the pores of the γ-Al2O3, wherein the M metal comprises Fe, Ni, Cu or Ce. The supported catalyst provided by the present invention uses γ-Al2O3 as a carrier, which gives the supported catalyst a mesoporous structure, providing more effective contact between the catalytic active sites and the reactants; Zr and M metals are used as active components to form a bimetallic supported solid acid catalyst; the synergistic effect of the bimetallic gives the supported catalyst stronger acidity and a higher content of Bronsted and Lewis acid sites. Using the supported catalyst for catalytic desorption of CO2-rich organic amine solution enables it to be desorbed at a lower temperature, reducing regeneration costs.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide capture technology, specifically relating to a supported catalyst, its preparation method and application, and a method for regenerating organic amine solutions. Background Technology

[0002] According to the IPCC's Climate Report 2023, the average atmospheric CO2 concentration rose from 280 ppm to 413 ppm between 2011 and 2020, compared to the period from 1850 to 1900, and the Earth's surface temperature has increased by 1.1°C, the highest in nearly 100,000 years. Excessive CO2 emissions are a major cause of global warming, and carbon capture, utilization, and storage (CCUS) is a crucial pathway to achieving low-carbon development. CCUS includes pre-combustion capture, oxy-fuel combustion capture, and post-combustion capture. Post-combustion capture technologies include membrane separation, solid-state adsorption, and chemical absorption, with organic amine solution absorption, represented by monoethanolamine (MEA), currently being the most widely used.

[0003] MEA has advantages such as low price, fast reaction kinetics and high CO2 absorption capacity, but the temperature required for desorbing CO2 is as high as 110 to 130°C, resulting in extremely high regeneration energy consumption. The regeneration cost accounts for about 70 to 80% of the operating cost of CO2 capture devices, and it is also prone to problems such as solution degradation and equipment corrosion. Summary of the Invention

[0004] In view of this, the present invention provides a supported catalyst, its preparation method and application, and a method for regenerating organic amine solutions. The supported catalyst provided by the present invention can reduce the desorption temperature and significantly reduce the energy consumption for regenerating organic amine solutions when used to catalyze the desorption of carbon dioxide from organic amine solutions.

[0005] To address the aforementioned technical problems, the present invention provides a supported catalyst comprising γ-Al2O3 and Zr and M metals supported on the surface and pores of the γ-Al2O3, wherein the M metal comprises Fe, Ni, Cu or Ce.

[0006] Preferably, the Zr content in the supported catalyst is 9-11% by mass;

[0007] The supported catalyst contains 9-11% by mass of metal M.

[0008] Preferably, the specific surface area of ​​the supported catalyst is 90.2–120.4 m². 2 / g, with a mesoporous surface area of ​​82.6–116.6 m². 2 / g, with an average pore size of 7.64–8.82 nm and acid sites of 0.1905–0.2914 mmol / g.

[0009] This invention also provides a method for preparing the supported catalyst described in the above technical solution, comprising the following steps:

[0010] A primary supported catalyst was obtained by impregnating a mixture of soluble salts of Zr, soluble salts of M metal, γ-Al2O3, and water.

[0011] The primary supported catalyst is calcined to obtain the supported catalyst.

[0012] Preferably, the mixing includes the following steps:

[0013] The soluble salt of Zr is dissolved in a portion of water to obtain a solution of the first active component;

[0014] The soluble salt of the metal M is dissolved in the first active component solution to obtain a dual active component solution;

[0015] γ-Al2O3 was added to the dual-active component solution.

[0016] Preferably, the impregnation time is 10-14 hours, and the impregnation is accompanied by stirring;

[0017] The impregnation process further includes: evaporating the impregnated system, drying the solid obtained after evaporation, and obtaining the primary supported catalyst.

[0018] Preferably, the calcination temperature is 500-600℃, and the calcination holding time is 3-5 hours.

[0019] Preferably, the heating rate to the required calcination temperature is 4–6 °C / min.

[0020] The present invention also provides the application of the supported catalyst described in the above technical solution or the supported catalyst prepared by the preparation method described in the above technical solution in the desorption of carbon dioxide from organic amine solution.

[0021] The present invention also provides a method for regenerating an organic amine solution, comprising the following steps:

[0022] A catalyst is added to an organic solution containing adsorbed carbon dioxide to desorb it, and the carbon dioxide is collected.

[0023] The catalyst is the supported catalyst described in the above technical solution or the supported catalyst prepared by the preparation method described in the above technical solution;

[0024] The desorption temperature is 88–100°C.

[0025] This invention provides a supported catalyst comprising γ-Al₂O₃ and Zr and M metals supported on the surface and pores of the γ-Al₂O₃, wherein the M metal includes Fe, Ni, Cu, or Ce. The supported catalyst provided by this invention uses γ-Al₂O₃, which has a large specific surface area, mesoporous structure, and excellent thermal stability, as a support, endowing the supported catalyst with a mesoporous structure and providing more effective contact between the catalytic active sites and reactants. This invention uses Zr and M metals as active components, combining them to form a bimetallic supported solid acid catalyst. The synergistic effect of the bimetals endows the supported catalyst with stronger acidity and a higher content of Bronsted and Lewis acid sites, promoting the two key steps of the desorption reaction, namely, the MEACOO ester reaction. — Cleavage and protonated amine MEAH + The deprotonation of organic amines is achieved by using the supported catalyst provided by this invention to catalytically desorb CO2-rich organic amine solutions. This allows for desorption at lower temperatures (88–100°C), reducing the regeneration cost of organic amine CO2 capture methods. Attached Figure Description

[0026] Figure 1 The XRD patterns of the supported catalysts prepared in Comparative Example 1 and Examples 1-4 are shown.

[0027] Figure 2 The adsorption-desorption isotherms are shown for the catalysts prepared in Comparative Example 1 and Examples 1-4.

[0028] Figure 3 The NH3-TPD curves of the supported catalysts prepared in Comparative Example 1 and Examples 1-4 are shown.

[0029] Figure 4 The Py-IR spectra of the supported catalysts prepared in Examples 1-4 are shown below.

[0030] Figure 5 The curve shows the temperature change during the desorption reaction.

[0031] Figure 6 This is a schematic diagram of the CO2 absorption-desorption reaction device used in the test example;

[0032] Figure 7 A graph showing the change in carbon dioxide desorption rate under the catalysis of different catalysts;

[0033] Figure 8 The curves showing the change in carbon dioxide desorption under different catalysts;

[0034] Figure 9 Bar charts and line graphs showing the carbon dioxide desorption amount and relative energy consumption over 1000 s under different catalysts;

[0035] Figure 10 A bar chart comparing the energy consumption of desorption for 1000 seconds in each cycle of Test Example 2;

[0036] Figure 11 The XRD patterns of ZrNi / γ-Al2O3 before and after 8 cycles are shown.

[0037] Figure 12 The graph shows the change in CO2 loading in MEA solutions with and without ZrNi / γ-Al2O3. Detailed Implementation

[0038] The present invention provides a supported catalyst comprising γ-Al2O3 and Zr and M metals supported on the surface and pores of the γ-Al2O3, wherein the M metal comprises Fe, Ni, Cu or Ce.

[0039] In one specific embodiment of the present invention, the mass percentage of Zr in the supported catalyst can be 9-11%, or even 10%; the mass percentage of M metal in the supported catalyst can be 9-11%, or even 10%.

[0040] In one specific embodiment of the present invention, the specific surface area of ​​the supported catalyst can be 90.2–120.4 m². 2 / g, the mesoporous surface area can be 82.6~116.6m² 2 / g, with an average pore size of 7.64–8.82 nm and acid sites of 0.1905–0.2914 mmol / g.

[0041] In this invention, γ-Al₂O₃, as a Lewis acid, can promote the regeneration reaction of amines in CO₂-rich organic solutions. It provides an excellent channel structure for the reaction and also exerts its own catalytic effect. This invention supports Zr and M metal elements such as Fe, Ni, Cu, and Ce on γ-Al₂O₃ to form a bimetallic supported solid acid catalyst. By controlling the Bronsted and Lewis acid sites on the catalyst, a mesoporous structure and high specific surface area are endowed to improve the catalytic contact area of ​​the reaction. This enables the regeneration of CO₂-rich MEA saturated solutions at low temperatures below 100°C, effectively reducing the activation energy, lowering the carbon dioxide desorption temperature, and reducing regeneration energy consumption.

[0042] The supported catalyst provided by this invention is low in cost, has high recycling performance, and is easy to recover.

[0043] This invention also provides a method for preparing the supported catalyst described in the above technical solution, comprising the following steps:

[0044] A primary supported catalyst was obtained by impregnating a mixture of soluble salts of Zr, soluble salts of M metal, γ-Al2O3, and water.

[0045] The primary supported catalyst is calcined to obtain the supported catalyst.

[0046] This invention involves impregnating a mixture of a soluble salt of Zr, a soluble salt of M metal, γ-Al₂O₃, and water to obtain a primary supported catalyst. As a specific embodiment of this invention, the mixing process may include the following steps:

[0047] The soluble salt of Zr is dissolved in water to obtain a solution of the first active component;

[0048] The soluble salt of the metal M is dissolved in the first active component solution to obtain a dual active component solution;

[0049] γ-Al2O3 was added to the dual-active component solution.

[0050] In one specific embodiment of the present invention, the soluble salt of Zr can be Zr(NO3)4·5H2O; the water can be deionized water. In this invention, the dissolution of the soluble salt of Zr in water can be carried out under stirring conditions. The present invention has no special requirements for the stirring, as long as complete dissolution is achieved. The present invention also has no special requirements for the amount of water used, as long as complete dissolution is achieved.

[0051] In one specific embodiment of the present invention, the soluble salt of the metal M can be a soluble salt of Fe, a soluble salt of Ni, a soluble salt of Cu, or a soluble salt of Ce; the soluble salt of Fe can be Fe(NO3)3·9H2O, the soluble salt of Ni can be NiCl2·6H2O, the soluble salt of Cu can be Cu(NO3)2·3H2O, and the soluble salt of Ce can be Ce(NO3)3·6H2O. In another specific embodiment of the present invention, the mass ratio of the element M in the soluble salt of metal M to the element Zr in the soluble salt of Zr can be 0.8–1.2:1, or even 1:1.

[0052] In one specific embodiment of the present invention, the soluble salt of metal M can be dissolved in the first active component solution under stirring conditions. The stirring temperature can be 45-55°C or 50°C. The present invention has no special requirements for the stirring speed and time, as long as the mixture can be homogeneous.

[0053] In one specific embodiment of the present invention, the mass ratio of Zr element in the soluble salt of γ-Al2O3 and Zr can be 10:0.8 to 1.2, or it can be 10:1.

[0054] As a specific embodiment of the present invention, the impregnation time can be 10-14 hours, or 11-12 hours; the impregnation can be accompanied by stirring; the present invention has no special limitation on the stirring, and stirring can enable the active components to fully enter the γ-Al2O3 channels.

[0055] In one specific embodiment of the present invention, the impregnation process may further include: evaporating the impregnated system, and drying the solid obtained after evaporation to obtain the primary supported catalyst. In this invention, the evaporation temperature can be 80–90°C, or even 85°C; the evaporation can be carried out with constant temperature stirring in a water bath. The present invention does not have special requirements for the evaporation time, as long as the solvent is removed. In this invention, the drying temperature can be 100–120°C, or even 110–115°C; the drying time can be 10–14 hours, or even 11–12 hours; the drying can be carried out in an oven.

[0056] After obtaining the primary supported catalyst, the present invention calcines the primary supported catalyst to obtain the supported catalyst. In one specific embodiment of the present invention, the process before calcination may further include crushing the primary supported catalyst. The present invention has no special requirements on the particle size of the crushed product; crushing or calcining the primary supported catalyst facilitates complete calcination. In one specific embodiment of the present invention, the calcination temperature can be 500–600°C, or 550–580°C; the calcination holding time can be 3–5 hours, or 4 hours; the heating rate to the required calcination temperature can be 4–6°C / min, or 5°C / min; the calcination can be carried out in a muffle furnace.

[0057] As a specific embodiment of the present invention, the calcination process may further include: cooling the calcined product to room temperature; the room temperature may be 20-35°C or 25-30°C.

[0058] The present invention also provides the application of the supported catalyst described in the above technical solution or the supported catalyst prepared by the preparation method described in the above technical solution in the desorption of carbon dioxide from organic amine solution.

[0059] The present invention also provides a method for regenerating an organic amine solution, comprising the following steps:

[0060] A catalyst is added to an organic solution containing adsorbed carbon dioxide to desorb it, and the carbon dioxide is collected.

[0061] The catalyst is the supported catalyst described in the above technical solution or the supported catalyst prepared by the preparation method described in the above technical solution;

[0062] The desorption temperature is 88–100°C, or it can be 91–98°C, or it can be 91–95°C.

[0063] In one specific embodiment of the present invention, the organic solution adsorbed with carbon dioxide can be a monoethanolamine solution adsorbed with carbon dioxide, or a monoethanolamine solution saturated with adsorbed carbon dioxide.

[0064] As a specific embodiment of the present invention, the amount of catalyst added to the organic solution adsorbed with carbon dioxide can be 1 to 3 wt%, that is, 0.5 to 1.5 g of catalyst is added to 50 mL of organic solution adsorbed with carbon dioxide.

[0065] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0066] Example 1

[0067] Dissolve 0.6g of Zr(NO3)4·5H2O (Aladdin) in 80mL of deionized water and stir to dissolve to obtain zirconium nitrate solution;

[0068] Add Fe(NO3)3·9H2O (Aladdin) with a net Fe content of 0.6g to a zirconium nitrate solution and stir until homogeneous at 50℃ to obtain a zirconium and iron dual-active component solution;

[0069] 6g of support γ-Al2O3 (Aladdin) was added to the zirconium and iron dual active component solution. After stirring and impregnation at room temperature (30℃) for 12h, the solution was evaporated by stirring at a constant temperature in a water bath at 85℃. The solid obtained after evaporation was placed in an oven and dried at 110℃ in air atmosphere for 12h to obtain a primary supported catalyst.

[0070] The primary supported catalyst solid material was crushed and placed in a muffle furnace. The temperature was increased to 550°C at a rate of 5°C / min, starting at 25°C. The catalyst was calcined at 550°C for 4 hours and then cooled to room temperature (30°C) to obtain the supported catalyst, denoted as ZrFe / γ-Al2O3.

[0071] Example 2

[0072] The supported catalyst was prepared according to the method of Example 1, except that Fe(NO3)3·9H2O (Aladdin) with a net Fe content of 0.6g was replaced with NiCl2·6H2O (Aladdin) with a net Ni content of 0.6g. The resulting supported catalyst was denoted as ZrNi / γ-Al2O3.

[0073] Example 3

[0074] The supported catalyst was prepared according to the method of Example 1, except that Fe(NO3)3·9H2O (Aladdin) with a net Fe content of 0.6g was replaced with Cu(NO3)2·3H2O (Aladdin) with a net Cu content of 0.6g. The resulting supported catalyst was denoted as ZrCu / γ-Al2O3.

[0075] Example 4

[0076] The supported catalyst was prepared according to the method of Example 1, except that Fe(NO3)3·9H2O (Aladdin) with a net Fe content of 0.6g was replaced with Ce(NO3)3·6H2O (Aladdin) with a net Ce content of 0.6g. The resulting supported catalyst was denoted as ZrCe / γ-Al2O3.

[0077] Comparative Example 1

[0078] γ-Al2O3 from Example 1 was used as a comparative example.

[0079] The supported catalysts prepared in Examples 1-4 were subjected to X-ray diffraction analysis to obtain XRD patterns, as shown below. Figure 1 As shown. Figure 1 It can be seen that the diffraction peaks of γ-Al2O3 in the supported catalyst are consistent with previous literature reports. The main characteristic peaks of ZrNi / γ-Al2O3 at 2θ of 66.89°, 45.88°, and 37.71° are in good agreement with the (440), (400), and (311) crystal planes of Al2O3 (PDF#04-007-2615), indicating that the intercalation of Zr and Ni did not significantly change the structure of the γ-Al2O3 support. ZrCu / γ-Al2O3, ZrFe / γ-Al2O3, and ZrCe / γ-Al2O3 also have diffraction peaks at the (440) and (400) crystal plane positions corresponding to the support, but the peak intensities are reduced or shifted, and the characteristic peak at the (311) crystal plane position disappears or becomes weak. The XRD test results show that the supported catalysts prepared in the examples all maintain a structure basically consistent with the support, confirming the successful synthesis of bimetallic supported γ-Al2O3 solid acid catalysts.

[0080] Nitrogen adsorption-desorption tests were conducted on the γ-Al₂O₃ in Comparative Example 1 and the supported catalysts prepared in Examples 1-4, and adsorption-desorption isotherms were obtained, as shown below. Figure 2 As shown in Table 1, the structure and physical properties of the catalyst were calculated based on the adsorption-desorption isotherms.

[0081] Table 1. Physical properties of the catalysts prepared in Comparative Examples 1 and Examples 1-4

[0082]

[0083]

[0084] According to the catalyst classification defined by the International Union of Pure and Applied Chemistry (IUPAC), the isotherm shape and hysteresis ring of all catalysts belong to type IV and type H3, indicating that the supported catalyst provided by this invention has a mesoporous and slit-like pore structure.

[0085] Table 1 summarizes the textural properties of the five catalysts. The results show that the surface area, pore size, and pore volume of the supported catalyst prepared in the examples are all lower than those of γ-Al₂O₃. This is because the incorporated metal fills part of the pores in the support, causing pore blockage. The pore volume difference between ZrM / γ-Al₂O₃ is relatively small, and the mesoporous surface area is ranked as follows: ZrCe / γ-Al₂O₃ > ZrFe / γ-Al₂O₃ > ZrCu / γ-Al₂O₃ > ZrNi / γ-Al₂O₃. ZrNi / γ-Al₂O₃ has the largest pore size at 8.32 nm. According to the IUPAC classification of mesoporous diameter range (2 ≤ d ≤ 50 nm), even with the decrease in average pore size, ZrM / γ-Al₂O₃ still belongs to the mesoporous material category. A higher mesoporous surface area and larger pore size are beneficial for exposing the catalytic active sites of ZrM / γ-Al₂O₃ to the CO₂-MEA solution, enhancing the effective contact and interaction between the catalyst and reactants, thereby promoting the regeneration reaction of the organic amine solution.

[0086] The desorption curves of γ-Al₂O₃ in Comparative Example 1 and the supported catalysts prepared in Examples 1-4 were determined by NH₃-TPD as follows: Figure 3As shown, based on the acid strength classification method, the NH3-TPD peak can be divided into three regions: a weak acid region (below 200℃), a medium-strong acid region (200–400℃), and a strong acid region (above 400℃). According to the temperature range corresponding to the peaks, all five catalysts contain weak and medium-strong acid sites, with ZrFe / γ-Al2O3 having the highest weak acid content. Notably, only ZrNi / γ-Al2O3 shows a significant NH3 desorption peak in the high-temperature region, indicating that Zr and Ni, after being loaded with γ-Al2O3, generate strong acid sites, exhibiting stronger acidity than the other catalysts. This corresponds to the excellent catalytic desorption performance of ZrNi / γ-Al2O3.

[0087] The supported catalysts prepared in Examples 1-4 were subjected to pyridine adsorption infrared spectroscopy (Py-IR) and the Py-IR spectra were obtained, as shown below. Figure 4 As shown, L represents the Lewis acid site and B represents the Bronsted acid site. According to... Figure 4 The content of acidic sites in the catalyst was calculated, and the results are listed in Table 2.

[0088] Table 2. Acidic sites of the supported catalysts prepared in Examples 1-4

[0089]

[0090]

[0091] Depend on Figure 4 It can be seen that pyridine molecules attach to the surface of solid acid through different pathways, 1450 cm⁻¹ -1 and 1600cm -1 The nearby spike corresponds to the LPy species formed by pyridine and L acid, 1540 cm⁻¹ -1 The absorption peak is related to Brønsted acid, at 1490 cm⁻¹. -1 The peak at that point is attributed to the simultaneous presence of L-acid and Brønsted acid.

[0092] Table 2 summarizes the contents of the two acids and the B / L ratio in ZrM / γ-Al2O3. The results show that ZrNi / γ-Al2O3 has the highest contents of both Brønsted (B) and Lewis (L) acids, at 0.0819 mmol / g and 0.2095 mmol / g, respectively. Brønsted (B) acids promote the dissociation of H2O molecules, generating a large number of active hydroxyl groups, providing the necessary protons for the desorption reaction and playing a crucial role in CO2 desorption. Lewis (L) acids originate from coordinated unsaturated metal atoms capable of accepting electron pairs, attacking isolated electron pairs and accelerating the breaking of the CN bond in the main reactant, urethane, during the desorption process. It can be concluded that the acid sites in ZrM / γ-Al2O3 play a key role in the CO2-MEA rich solution regeneration process.

[0093] The above performance test results show that the bimetallic supported solid acid catalyst ZrM / γ-Al2O3 provided by the present invention has excellent mesoporous structure and acidic properties, and exhibits excellent catalytic performance in the desorption reaction of CO2-rich MEA solution.

[0094] Test Example 1

[0095] The catalytic desorption performance of the catalysts ZrM / γ-Al2O3 (M being Fe, Ni, Cu, Ce) prepared in Examples 1-4 was tested according to the following method:

[0096] Temperature data points are controlled in real time by thermocouples inside the water bath and temperature sensors inside the flask, resulting in a temperature change curve for the desorption reaction. Figure 5 As shown.

[0097] A 100 mL four-necked flask was used as the CO2 absorption-desorption reaction apparatus for MEA solution, equipped with a magnetic stirrer, temperature sensor, water bath, desiccant, condenser, circulating condensate tank, and power meter. An external non-dispersive infrared (NDIR) analyzer was connected to measure the outlet CO2 concentration. A mixture of CO2 and N2 gas was passed into a 30% (5 mol / L) monoethanolamine (MEA) solution, and after absorption at 40 °C and 500 rpm for a certain time, 50 mL of a saturated solution with a loading of 0.5 mol CO2 / mol MEA was obtained. Add 2 wt% (1 g) of ZrM / γ-Al2O3 catalyst, heat to 91 °C at 500 rpm, hold at 1 h (3600 s), purge CO2 generated by desorption reaction with N2 at a flow rate of 100 mL / min, condense and dry the CO2 and enter a gas analyzer to measure the CO2 concentration. Based on the measured data, the desorption rate, desorption amount and relative energy consumption of CO2 were calculated and the results are listed in Table 3. Figure 6 This is a schematic diagram of a CO2 absorption-desorption reaction apparatus; the curves showing the change in carbon dioxide desorption rate under different catalysts are shown below. Figure 7 As shown in the figure, the curves of carbon dioxide desorption under different catalysts are as follows: Figure 8 As shown in the figure, the relative energy consumption of carbon dioxide desorption under different catalysts is plotted as follows: Figure 9 As shown.

[0098] The desorption performance is calculated as follows:

[0099]

[0100]

[0101]

[0102]

[0103] In the formula, Let t be the amount of CO2 desorbed at time t, in mmol; N2 flow rate, mL / min; x, CO2 volume concentration in the gas mixture, %; V m Dr is the molar volume of the gas, L / mol; Dr is the CO2 desorption rate, mmol / min; E is the power consumption measured by the power meter, kJ; H i Energy consumption for regeneration of the catalyst assembly, kJ / mol; H benchmark The energy consumption of the MEA blank group is expressed in kJ / mol; RH represents the relative energy consumption of the catalytic group compared to the blank group, expressed as a percentage.

[0104] Table 3. Catalytic desorption performance of CO2-rich MEA solutions

[0105]

[0106]

[0107] Table 3 shows that, compared with the MEA solution blank group without catalyst, the four ZrM / γ-Al2O3 solid acids prepared in Examples 1-4 increased the peak desorption rate by 37.4%-46.86%, the maximum increase in real-time desorption rate by 463.77%-836.52%, the desorption amount by 64.79%-81.66%, and reduced the relative energy consumption by 39.31%-44.96%. Among Examples 1-4, ZrNi / γ-Al2O3 showed the best catalytic desorption effect, increasing the CO2 peak desorption rate by 46.86%, the maximum increase in real-time CO2 desorption rate by 836.52%, the CO2 desorption amount by 81.66%, and the relative energy consumption by 44.96%.

[0108] Combined with Table 3 and Figure 7 It can be seen that with the extension of desorption time, the CO2 desorption rate of each group showed a trend of first increasing and then decreasing. The blank group had the slowest reaction, followed by γ-Al2O3, while the ZrM / γ-Al2O3 group showed a significantly faster reaction. Among them, ZrNi / γ-Al2O3 had the highest desorption kinetics, reaching a peak desorption rate of 1.92 mmol / min at 548 s, ZrCu / γ-Al2O3 reached 1.87 mmol / min at 561 s, and γ-Al2O3 and the blank group reached 1.37 mmol / min at 709 s and 1.30 mmol / min at 869 s, respectively, indicating that ZrM / γ-Al2O3 can achieve a faster reaction rate at a lower temperature.

[0109] Figure 8It reflects the change trend of CO2 desorption amount. In the early stage of the heating process, the desorption reaction progresses slowly. After 400 s, the growth rate of CO2 desorption amount in the catalytic group is significantly faster than that in the blank group, indicating that the catalyst reduces the energy barrier that needs to be overcome in the reaction. As the reaction enters the later stage, the relative increment of CO2 desorption amount between the catalytic group and the blank group gradually shrinks, and each group gradually approaches the chemical equilibrium of the desorption reaction.

[0110] Figure 9 The results show that the relative heat loads of different catalysts are ranked as: ZrNi / γ-Al2O3 < ZrFe / γ-Al2O3 < ZrCe / γ-Al2O3 < ZrCu / γ-Al2O3 < γ-Al2O3 < blank group. ZrNi / γ-Al2O3 has the best energy consumption reduction effect, reducing the heat load by 44.96%, while γ-Al2O3 only reduces it by 17.7%. Therefore, after the bimetallic modification of γ-Al2O3, the reaction activation energy is effectively reduced, which greatly promotes the detachment of CO2 from the solution and improves the bottleneck problem of high regeneration energy consumption of the CO2-MEA solution.

[0111] Test Example 2

[0112] The CO2 absorption-desorption cycle performance of ZrNi / γ-Al2O3 was tested 8 times according to the method of Test Example 1. The absorption process lasted for 1200 s, and the desorption process lasted for 3600 s. The specific test parameters were: 91 °C, 500 rpm, 50 mL of MEA solution with a CO2 loading of 0.5 mol / mol, and 2 wt% ZrNi / γ-Al2O3 was added.

[0113] Calculate the energy consumption for 1000 s of desorption, and draw a column comparison chart of the results, as Figure 10 shown. The CO2-MEA rich solution of ZrNi / γ-Al2O3 was tested for 8 absorption-desorption cycle reactions, proving its catalytic performance and structural stability. After 8 cycles, the energy consumption of the ZrNi / γ-Al2O3 catalytic group was still reduced by 23.1% compared with the blank group.

[0114] The ZrNi / γ-Al2O3 after 8 cycles was detected by XRD, and the XRD spectrum was obtained, as Figure 11 shown. Figure 11 It can be seen that the XRD diffraction peaks of ZrNi / γ-Al2O3 before and after cycling are basically the same, and its structure hardly changes, proving its structural stability and high cycling performance.

[0115] Test Example 3

[0116] The CO2 absorption performance of ZrNi / γ-Al2O3 was tested using the apparatus described in Test Example 1. The specific test parameters were: 50 mL of a 5 mol / L MEA solution, with the addition of 2 wt% ZrNi / γ-Al2O3, and CO2 absorption at 40℃ and 500 rpm for 1200 s. The resulting curves showing the CO2 loading changes in the MEA solution with and without ZrNi / γ-Al2O3 are shown below. Figure 12 As shown.

[0117] Depend on Figure 12 The results showed that, regardless of the addition of ZrNi / γ-Al2O3, the CO2 loading exhibited a trend of initially increasing rapidly, then increasing slowly, and finally reaching a plateau. The two absorption curves were highly consistent. Therefore, within the experimental error range, ZrNi / γ-Al2O3 has no negative effect on the CO2 absorption performance of MEA solutions.

[0118] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. The application of a supported catalyst in the desorption of carbon dioxide from an organic amine solution, characterized in that, The supported catalyst comprises γ-Al₂O₃ and Zr and M metal supported on the surface and pores of the γ-Al₂O₃, wherein the M metal comprises Fe, Ni, Cu, or Ce; the mass percentage of Zr in the supported catalyst is 9-11%; the mass percentage of M metal in the supported catalyst is 9-11%; and the specific surface area of ​​the supported catalyst is 90.2-120.4 m². 2 / g; The method for preparing the supported catalyst includes the following steps: A primary supported catalyst was obtained by impregnating a mixture of soluble salts of Zr, soluble salts of M metal, γ-Al2O3, and water. The primary supported catalyst is calcined to obtain the supported catalyst.

2. The application according to claim 1, characterized in that, The supported catalyst has a mesoporous surface area of ​​82.6~116.6 m². 2 / g, with an average pore size of 7.64~8.82nm and acid sites of 0.1905~0.2914mmol / g.

3. The application according to claim 1, characterized in that, The mixing process includes the following steps: The soluble salt of Zr is dissolved in a portion of water to obtain a solution of the first active component; The soluble salt of the metal M is dissolved in the first active component solution to obtain a dual active component solution; γ-Al2O3 was added to the dual-active component solution.

4. The application according to claim 1, characterized in that, The soaking time is 10-14 hours, and the soaking is accompanied by stirring.

5. The application according to claim 1 or 4, characterized in that, The impregnation process further includes: evaporating the impregnated system, drying the solid obtained after evaporation, and obtaining the primary supported catalyst.

6. The application according to claim 1, characterized in that, The calcination temperature is 500~600℃, and the calcination holding time is 3~5h.

7. The application according to claim 6, characterized in that, The heating rate to the required calcination temperature is 4~6℃ / min.

8. The application according to claim 1, characterized in that, The application specifically includes the following steps: A supported catalyst was added to an organic amine solution containing adsorbed carbon dioxide to desorb the adsorbed carbon dioxide and collect the carbon dioxide. The desorption temperature is 88~100℃.

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