Application of bifunctional material for carbon dioxide capture coupled with dry reforming of methane in oxygen-containing flue gas treatment

Abstract

This invention relates to the field of oxygen-containing flue gas treatment technology, specifically to the application of a bifunctional material combining carbon dioxide capture and methane dry reforming in oxygen-containing flue gas treatment. The invention provides the application of a bifunctional material combining carbon dioxide capture and methane dry reforming in oxygen-containing flue gas treatment. The bifunctional material is a copper-modified nickel / calcium oxide composite material, which can suppress in-situ delayed reaction (ICCU) and carbon deposition. This invention utilizes a copper-modified nickel / calcium oxide composite material to obtain the bifunctional material and provides the possibility of applying the bifunctional material to high-efficiency ICCU-DRM in oxygen-containing flue gas.

Description

Technical Field

[0001] This invention relates to the field of oxygen-containing flue gas treatment technology, specifically to the application of bifunctional materials that combine carbon dioxide capture with methane dry reforming in oxygen-containing flue gas treatment. Background Technology

[0002] Recently, with the annual increase in carbon dioxide (CO2) emissions, environmental problems have become increasingly serious. To reduce CO2 emissions and achieve the "dual carbon" goal, integrated carbon capture and utilization (ICCU) technology has emerged. ICCU technology couples CO2 capture and CO2 conversion technologies to achieve CO2 capture and in-situ conversion in the same reactor at the same temperature, significantly reducing industrial energy consumption and showing promising application prospects. CO2 adsorbents are typically classified into high-temperature (>400℃), medium-temperature (200–400℃), and low-temperature (<200℃) adsorbents based on their CO2 capture temperature. In the conversion stage, it is usually coupled with dry reforming of methane (DRM), reverse-flow gasification, and methanation reactions (Equations 1–3). DRM can convert two greenhouse gases, CO2 and CH4, into usable syngas (H2 and CO). When DRM is effectively combined with CO2 capture, the energy consumption for CO2 utilization and the fuel demand for syngas production are lower than those of traditional DRM. Therefore, integrated CO2 capture and utilization coupled with methane dry reforming (ICCU-DRM) technology is a very promising CO2 emission reduction technology.

[0003] CO2 + CH4 → 2CO + 2H2, ΔH 298K = +247 kJ·mol -1 (1)

[0004] CO2 + H2 → CO + H2O, ΔH 298K = +41.2 kJ·mol -1 (2)

[0005] CO2 + 4H2 → CH4 + 2H2O, ΔH 298K = -165 kJ·mol -1 (3)

[0006] For ICCU-DRM technology, it is necessary to develop dual-functional materials (DFMs) with both adsorption and catalytic sites to achieve rapid and stable CO2 capture and conversion efficiency. CaO is widely found in nature and is characterized by low cost and high theoretical CO2 absorption capacity, and is usually used as an adsorbent. Ni, due to its low cost and high catalytic activity, is considered a highly efficient metal element for converting CO2 and CH4, two bond-stabilized compounds, and is used together with CaO to achieve CO2 capture coupled with calcium-looping dry reforming of methane (CaLDRM). By switching the atmosphere in a single reactor, the CO2 capture and conversion stages can be carried out continuously. Moreover, the consumption of CO2 during the reaction process reduces the partial pressure of CO2 in the reactor, promotes the calcination of CaCO3, and to some extent reduces the temperature required for the calcination reaction, thereby mitigating the deactivation of CaO caused by sintering.

[0007] However, the in-situ delay in DRM caused by the passivation of catalytic components by O2 in actual flue gas cannot be ignored. Due to the presence of O2 in the carbon source, the active component Ni is oxidized to NiO, which has almost no catalytic activity. When the in-situ DRM process begins, CH4 reduces NiO to Ni, resulting in a pre-reduction stage that delays CO2 conversion and further leads to a decrease in CO2 conversion rate. Furthermore, the adverse effects of O2 on the CaO structure also hinder CO2 capture performance.

[0008] Therefore, how to avoid the impact of DRM delay on the efficient realization of ICCU-DRM under oxygen-containing flue gas conditions is a problem worthy of attention. Summary of the Invention

[0009] This invention provides the application of a bifunctional material for carbon dioxide capture coupled with methane dry reforming in the treatment of oxygen-containing flue gas. This invention utilizes a copper-modified nickel / calcium oxide composite material. While retaining the bifunctional characteristics of the nickel / calcium oxide composite material's adsorption and catalytic sites, it uses copper to reduce nickel oxide to elemental nickel, ensuring that the activity of the nickel / calcium oxide composite material does not decrease in oxygen-containing flue gas. This significantly inhibits the DRM phenomenon and the formation of deactivating substances—carbon deposits—during the ICCU-DRM process, guaranteeing the high efficiency of the nickel / calcium oxide composite material in oxygen-containing flue gas ICCU-DRM.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] This invention provides the application of a bifunctional material for carbon dioxide capture coupled with methane dry reforming in the treatment of oxygen-containing flue gas. The bifunctional material is a copper-modified nickel / calcium oxide composite material, which can suppress in-situ delay phenomena and carbon deposition.

[0012] All nickel / calcium oxide composite materials mentioned in this application are actually composite materials of nickel oxide and calcium oxide, and are commonly referred to as nickel / calcium oxide composite materials in the art.

[0013] This application utilizes the excellent reduction properties of Cu. Furthermore, Cu can promote the activation of CH4 and generate active hydrogen (H*), which further promotes the reduction of NiO to elemental Ni to rapidly exert its catalytic effect, thus suppressing the in-situ delay of the DRM stage. Simultaneously, the CH4 conversion rate can be significantly improved, and it has a significant effect on reducing the H2 / CO ratio; the lower H2 / CO ratio indicates that carbon deposition is effectively suppressed.

[0014] This application provides a new application idea for copper-modified nickel / calcium oxide composite materials and solves the problem of achieving high-efficiency ICCU-DRM under oxygen-containing flue gas.

[0015] Preferably, in the treatment of oxygen-containing flue gas, the dual-functional material exhibits the following characteristics at a temperature of 600°C: a carbon dioxide conversion rate of 92-97%, a methane conversion rate of 42-57%, and an H2 / CO ratio of 2.35-2.36.

[0016] Preferably, the preparation method of the bifunctional material includes: dissolving copper salt, nickel salt, and calcium salt in water, adding anhydrous citric acid, stirring until the solution transforms into a gel state, drying, and calcining to obtain a copper-modified nickel / calcium oxide composite material.

[0017] Preferably, the bifunctional material is a copper and zirconium oxide modified nickel / calcium oxide composite material, which can suppress in-situ delay phenomenon and carbon deposition.

[0018] This application utilizes the excellent reduction properties of Cu. Furthermore, Cu can promote CH4 activation and generate active hydrogen (H*), further promoting the reduction of NiO to elemental Ni for rapid catalytic action, thus suppressing the in-situ delay of the DRM stage. Simultaneously, the CH4 conversion rate is significantly improved, and it has a significant effect on reducing the H2 / CO ratio; the lower H2 / CO ratio indicates effective suppression of carbon deposition. ZrO2, due to its high Taman temperature, is used as a stabilizer to improve the cycling performance of CaO, thereby enhancing the overall cycling stability of the bifunctional material.

[0019] Modifying nickel / calcium oxide composites by utilizing the strong reducing properties of Cu and the high stability of ZrO2 can effectively suppress in-situ DRM delay caused by oxygen-containing flue gas and improve CaLDRM performance, thereby achieving a significant increase in CH4 conversion rate and recycling under actual flue gas conditions, making its application in actual industry possible.

[0020] In summary, this application provides a new application approach for copper and zirconium oxide modified nickel / calcium oxide composite materials and solves the problem of achieving high-efficiency ICCU-DRM under oxygen-containing flue gas.

[0021] Preferably, in the treatment of oxygen-containing flue gas, the bifunctional material achieves the following results: at a temperature of 600°C, the carbon dioxide conversion rate is 98-99%, the methane conversion rate is 44-55%, and the H2 / CO ratio is 2.00-2.12; after 5 cycles at a temperature of 650°C, the methane conversion rate is 66.44%.

[0022] Preferably, the preparation method of the bifunctional material includes: dissolving copper salt, zirconium salt, nickel salt, and calcium salt in water, adding anhydrous citric acid, stirring until the solution transforms into a gel state, drying, and calcining to obtain a copper and zirconium oxide modified nickel / calcium oxide composite material.

[0023] Preferably, the copper salt, zirconium salt, nickel salt, and calcium salt are copper nitrate, zirconium nitrate, nickel nitrate, and calcium nitrate, respectively.

[0024] Preferably, the molar ratio of the nickel salt to the copper salt is (1-9):1.

[0025] More preferably, the molar ratio of the nickel salt to the copper salt is (2-9):1.

[0026] More preferably, the molar ratio of the nickel salt to the copper salt is (5-9):1.

[0027] More preferably, the molar ratio of the nickel salt to the copper salt is 9:1.

[0028] Preferably, the sum of the molar amounts of the copper salt, zirconium salt, nickel salt, and calcium salt is a mol, the molar amount of the anhydrous citric acid is a mol, and the molar amount of the water is 30a to 45a mol.

[0029] Here, 'a' can be any value greater than zero. The applicant would like to emphasize the proportional relationship between the sum of the molar amounts of copper salt, zirconium salt, nickel salt, and calcium salt, the molar amount of anhydrous citric acid, and the molar amount of water.

[0030] Preferably, the stirring temperature is 85–100°C.

[0031] More preferably, the stirring temperature is 90°C.

[0032] Preferably, the drying temperature is 120–140°C, and the drying time is 8–24 hours.

[0033] More preferably, the drying temperature is 130°C and the drying time is 12 hours.

[0034] Preferably, the calcination temperature is 650–750°C, the calcination time is 3–5 h, and the calcination heating rate is 4–6°C / min.

[0035] More preferably, the calcination temperature is 700℃, the calcination time is 4h, and the calcination heating rate is 5℃ / min.

[0036] Therefore, the present invention has the following beneficial effects:

[0037] (1) This invention utilizes copper-modified nickel / calcium oxide composite material to obtain bifunctional material and provides the possibility of applying bifunctional material to high-efficiency ICCU-DRM under oxygen-containing flue gas.

[0038] (2) The present invention utilizes copper and zirconium oxide modified nickel / calcium oxide composite material to obtain bifunctional material, which effectively suppresses the delayed phenomenon of conversion stage after capturing oxygen-containing flue gas, and improves CH4 conversion rate by more than 10%; it has good cycling stability at high temperature, and still has stable and considerable conversion performance after 5 cycles at 650℃; compared with nickel / calcium oxide composite material under the same conditions, it has better anti-carbon deposition performance.

[0039] (3) This invention provides a method to suppress DRM phenomenon and resist carbon deposition by using copper-modified nickel / calcium oxide composite material, which broadens the realization path of efficient ICCU-DRM under oxygen-containing flue gas.

[0040] (4) This invention provides a nickel / calcium oxide composite material modified with copper and zirconium oxide that can suppress DRM phenomenon and resist carbon deposition while realizing the recycling of dual-function materials, greatly reducing the cost of using dual-function materials and facilitating industrial application. Attached Figure Description

[0041] Figure 1 The images are transmission electron microscope images of Ni9Cu1-CaZr before and after the reaction, where a is before the reaction and b is after the reaction.

[0042] Figure 2 This is a real-time curve showing the change in gas concentration during the performance testing of the bifunctional material.

[0043] Figure 3 This is a real-time curve showing the gas concentration change during the performance testing of bifunctional materials at different temperatures. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0045]

Example

[0046] Example 1

[0047] 1. Preparation of the bifunctional material: 1.0469 g of nickel nitrate (Ni(NO3)2·6H2O), 0.0966 g of copper nitrate (Cu(NO3)2·3H2O), 8.5014 g of calcium nitrate (Ca(NO3)2·4H2O), and 1.7178 g of zirconium nitrate (Zr(NO3)4·5H2O) were dissolved in 31.68 mL of deionized water and stirred until homogeneous. 8.4537 g of anhydrous citric acid was added to the mixed solution and stirred at room temperature for 1 h. The solution was then placed in a 90 °C oil bath and stirred vigorously until a gel state was reached, followed by drying at 130 °C overnight. The dried solid was then calcined in a muffle furnace at 700 °C for 4 h at a heating rate of 5 °C / min. The resulting bifunctional material was named Ni9Cu1-CaZr. In this example, Ni... 2+ :Cu 2+ The molar ratio is 9:1.

[0048] 2. Simulated CO2 capture coupled with methane dry reforming experiment in oxygen-containing flue gas

[0049] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to 600℃ at a rate of 5℃ / min;

[0050] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0051] (3) Purge with N2 for 5 minutes;

[0052] (4) CO2 capture stage: 10% CO2, 6.7% O2, N2 as equilibrium gas, reaction time 60 min;

[0053] (5) Purge with N2 for 5 minutes;

[0054] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0055] (7) Purge with N2 for 5 minutes.

[0056] The reaction temperature throughout the process was 600℃, and the total flow rate was 100mL / min.

[0057] Example 2

[0058] This embodiment is basically the same as Embodiment 1, except that: Ni 2+ :Cu 2+ The molar ratio was 7:3, and the amounts added were: 0.8142 g nickel nitrate (Ni(NO3)2·6H2O) and 0.2899 g copper nitrate (Cu(NO3)2·3H2O). The resulting bifunctional material was named Ni7Cu3-CaZr.

[0059] Example 3

[0060] This embodiment is basically the same as Embodiment 1, except that: Ni 2+ :Cu 2+ The molar ratio was 5:5, and the amounts added were: 0.5816 g of nickel nitrate (Ni(NO3)2·6H2O) and 0.4832 g of copper nitrate (Cu(NO3)2·3H2O). The resulting bifunctional material was named Ni5Cu5-CaZr.

[0061] Example 4

[0062] 1. Preparation of the bifunctional material: 1.0469 g of nickel nitrate (Ni(NO3)2·6H2O), 0.0966 g of copper nitrate (Cu(NO3)2·3H2O), and 8.5014 g of calcium nitrate (Ca(NO3)2·4H2O) were dissolved in 28.8 mL of deionized water and stirred until homogeneous. 7.6852 g of anhydrous citric acid was added to the mixed solution and stirred at room temperature for 1 h. The solution was then placed in a 90 °C oil bath and stirred vigorously until a gel state was reached, followed by drying at 130 °C overnight. The dried solid was then calcined in a muffle furnace at 700 °C for 4 h at a heating rate of 5 °C / min. The resulting bifunctional material was named Ni9Cu1-Ca. In this example, Ni... 2+ :Cu 2+ The molar ratio is 9:1.

[0063] 2. Simulated CO2 capture coupled with methane dry reforming experiment in oxygen-containing flue gas

[0064] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to 600℃ at a rate of 5℃ / min;

[0065] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0066] (3) Purge with N2 for 5 minutes;

[0067] (4) CO2 capture stage: 10% CO2, 6.7% O2, N2 as equilibrium gas, reaction time 60 min;

[0068] (5) Purge with N2 for 5 minutes;

[0069] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0070] (7) Purge with N2 for 5 minutes.

[0071] The reaction temperature throughout the process was 600℃, and the total flow rate was 100mL / min.

[0072] Comparative Example 1

[0073] 1. Preparation of the bifunctional material: 1.1632 g of nickel nitrate (Ni(NO3)2·6H2O), 8.5014 g of calcium nitrate (Ca(NO3)2·4H2O), and 1.7178 g of zirconium nitrate (Zr(NO3)4·5H2O) were dissolved in 31.68 mL of deionized water and stirred until homogeneous. 8.4537 g of anhydrous citric acid was added to the mixed solution and stirred at room temperature for 1 h. The solution was then placed in a 90 °C oil bath and stirred vigorously until a gel state was reached, followed by drying at 130 °C overnight. The dried solid was then calcined in a muffle furnace at 700 °C for 4 h at a heating rate of 5 °C / min. The resulting bifunctional material was named Ni-CaZr.

[0074] 2. Simulated CO2 capture coupled with methane dry reforming experiment in oxygen-containing flue gas

[0075] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to 600℃ at a rate of 5℃ / min;

[0076] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0077] (3) Purge with N2 for 5 minutes;

[0078] (4) CO2 capture stage: 10% CO2, 6.7% O2, N2 as equilibrium gas, reaction time 60 min;

[0079] (5) Purge with N2 for 5 minutes;

[0080] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0081] (7) Purge with N2 for 5 minutes.

[0082] The reaction temperature throughout the process was 600℃, and the total flow rate was 100mL / min.

[0083] Comparative Example 2

[0084] 1. Preparation of the bifunctional material: 1.1632 g of nickel nitrate (Ni(NO3)2·6H2O) and 8.5014 g of calcium nitrate (Ca(NO3)2·4H2O) were dissolved in 28.8 mL of deionized water and stirred until homogeneous. 7.6852 g of anhydrous citric acid was added to the mixed solution and stirred at room temperature for 1 h. The solution was then placed in a 90 °C oil bath and stirred vigorously until a gel state was reached, and dried overnight at 130 °C. The dried solid was then calcined in a muffle furnace at 700 °C for 4 h at a heating rate of 5 °C / min. The resulting bifunctional material was named Ni-Ca.

[0085] 2. Simulated CO2 capture coupled with methane dry reforming experiment in oxygen-containing flue gas

[0086] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to 600℃ at a rate of 5℃ / min;

[0087] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0088] (3) Purge with N2 for 5 minutes;

[0089] (4) CO2 capture stage: 10% CO2, 6.7% O2, N2 as equilibrium gas, reaction time 60 min;

[0090] (5) Purge with N2 for 5 minutes;

[0091] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0092] (7) Purge with N2 for 5 minutes.

[0093] The reaction temperature throughout the process was 600℃, and the total flow rate was 100mL / min.

[0094] [Performance Testing]

[0095] 1. TEM test

[0096] The Ni9Cu1-CaZr bifunctional material obtained in Example 1 was subjected to TEM testing, and the results are as follows: Figure 1 As shown. Observation Figure 1 It can be seen that the morphology of the nickel / calcium oxide composite material modified by Cu and ZrO2 did not change significantly after treating oxygen-containing flue gas.

[0097] from Figure 1The results show that the metal particles are uniformly dispersed in the support. Calculations of the particle size show that the average particle size before and after the reaction is 16.92 nm and 16.59 nm, respectively, remaining almost unchanged. This indicates that Ni9Cu1-CaZr can effectively inhibit Ni sintering and therefore has better resistance to coke deposition. At relatively high temperatures, the microstructure of Ni9Cu1-CaZr changes even less, which is undoubtedly related to its excellent cycling stability.

[0098] 2. Effects of DRM performance and Cu content

[0099] The experimental results of CO2 capture coupled with methane dry reforming in simulated oxygen-containing flue gas in Examples 1-3 and Comparative Example 1 are recorded in Table 1 and 2. Figure 2 middle.

[0100] Table 1 Comparison of Single-Cycle Performance of Different Bifunctional Materials

[0101]

[0102] As shown in Table 1, the CO2 capture capacity of the four groups of zirconia-modified materials is approximately 9 mmol / g. DFMs The samples without zirconium oxide exhibited higher CO2 capture due to their higher CaO content in the support; furthermore, the CO2 conversion rate was close to 100%, indicating extremely low CO2 escape at 600℃. Simultaneously, the in-situ delay phenomenon was suppressed due to the significant improvement of Cu's reducibility on the bifunctional material. Figure 2 Furthermore, when the Ni:Cu ratio was 9:1, the CH4 conversion rate was significantly improved, increasing by approximately 13%. However, as the Cu content further increased, the CH4 conversion rate gradually decreased, and the total yield (H2+CO) also slightly decreased. This is due to the performance degradation caused by the reduction of the active component Ni. Therefore, the Cu content is also an important factor affecting catalytic performance. Of the four sets of data above, the H2 / CO ratio in Example 1 was lower, indicating that the methane cracking side reaction (Equation 4) was weaker at this time, reducing carbon deposition and effectively suppressing the deactivation caused by carbon deposition covering the catalyst's active sites.

[0103] CH4→C+2H2,ΔH 298K = +75 kJ·mol -1 (4)

[0104] 3. The effect of temperature

[0105] Based on the results in "2. The Influence of DRM Phenomenon and Cu Content", Example 1, with a Ni:Cu molar ratio of 9:1, exhibits the best performance while suppressing in-situ delay in the conversion stage. Building upon this, the inventors selected Example 1 and Comparative Example 1 (without Cu doping) to explore the effect of temperature on the activity of the bifunctional material.

[0106] The reaction process and conditions are as follows:

[0107] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to the target temperature (625℃ / 650℃) at a rate of 5℃ / min;

[0108] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0109] (3) Purge with N2 for 5 minutes;

[0110] (4) CO2 capture stage: 10% CO2, 6.7% O2, nitrogen as the equilibrium gas, reaction time 60 min;

[0111] (5) Purge with N2 for 5 minutes;

[0112] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0113] (7) Purge with N2 for 5 minutes.

[0114] The total flow rate was 100 mL / min. The test results are shown in Table 2 and... Figure 3 .

[0115] Table 2. Effect of Temperature on Single-Cycle Performance of Bifunctional Materials

[0116]

[0117] observe Figure 3 The results in Table 2 show that the higher the temperature, the faster the reaction rate and the significantly reduced overall reaction time. Simultaneously, due to the stronger reactivity of active hydrogen at high temperatures, the delay time is also shortened, meaning the reduction time of NiO is reduced, thus greatly improving the CH4 conversion rate. Furthermore, Ni9Cu1-CaZr effectively suppresses the delay phenomenon at different temperatures, exhibiting superior conversion rates and H2 / CO ratios under the same operating conditions. This demonstrates that the addition of Cu not only improves conversion performance by enhancing the reducibility of the material to suppress the in-situ delay phenomenon caused by oxygen-containing flue gas, but also effectively inhibits carbon deposition and improves the material's stability.

[0118] 4. Cyclic stability

[0119] Based on the results in "2. The Influence of DRM Phenomenon and Cu Content", Example 1, with a Ni:Cu molar ratio of 9:1, exhibits the best performance while suppressing in-situ delay during the conversion stage. Building upon this, the inventors selected Example 1 and Comparative Example 1 (without Cu doping) for cycle stability studies.

[0120] The reaction process and conditions are as follows:

[0121] (1) Heating stage: Under N2 conditions, the temperature is increased from room temperature to 650℃ at a rate of 5℃ / min;

[0122] (2) Pre-reduction stage: 10% H2, N2 as equilibrium gas, reaction time 120 min;

[0123] (3) The temperature was increased from 600℃ to 650℃ under N2 atmosphere at a rate of 5℃ / min.

[0124] (4) CO2 capture stage: 10% CO2, 6.7% O2, N2 as equilibrium gas, reaction time 60 min;

[0125] (5) Purge with N2 for 5 minutes;

[0126] (6) Methane dry reforming stage: 2.5% CH4, reaction time 180 min;

[0127] (7) Purge with N2 for 5 minutes.

[0128] The total flow rate for the entire process was 100 mL / min. After performing the process once, steps (4) to (7) were repeated four times. The test results are shown in Table 3.

[0129] Table 3 Cyclic Performance Test Table for Bifunctional Materials As shown in Table 3, the CO yields of the two groups of bifunctional materials are similar, but Example 1 exhibits superior anti-carbon deposition performance due to its lower H2 / CO ratio. Furthermore, Example 1 shows less yield decay over 5 cycles, indicating better cycling stability at high temperatures.

[0130] In summary, the bifunctional material prepared in this invention exhibits excellent performance in the process of CO2 capture coupled with methane dry reforming in oxygen-containing flue gas. It not only effectively suppresses the delay in the conversion stage and improves the CH4 conversion rate, but also inhibits the occurrence of methane cracking side reactions. Furthermore, the material has a stable microstructure, improved resistance to carbon deposition, and excellent stability at high temperatures, demonstrating promising prospects for industrial applications.

Claims

1. The application of a bifunctional material for carbon dioxide capture coupled with methane dry reforming in oxygen-containing flue gas treatment, characterized in that, The bifunctional material is a copper-modified nickel / calcium oxide composite material, which can suppress in-situ delay phenomenon and carbon deposition; In the treatment of oxygen-containing flue gas, the bifunctional material exhibits the following characteristics at 600°C: a carbon dioxide conversion rate of 92-97%, a methane conversion rate of 42-57%, and an H2 / CO ratio of 2.35-2.

36. The preparation method of the bifunctional material includes: dissolving copper salt, nickel salt, and calcium salt in water, adding anhydrous citric acid, stirring until the solution transforms into a gel state, drying, and calcining at 700℃ for 4 hours to obtain a copper-modified nickel / calcium oxide composite material.

2. The application of a bifunctional material for carbon dioxide capture coupled with methane dry reforming in oxygen-containing flue gas treatment, characterized in that, The bifunctional material is a copper and zirconium oxide modified nickel / calcium oxide composite material, which can suppress in-situ delay phenomenon and carbon deposition; In the treatment of oxygen-containing flue gas, the bifunctional material exhibits the following results: at 600°C, the carbon dioxide conversion rate is 98-99%, the methane conversion rate is 44-55%, and the H2 / CO ratio is 2.00-2.12; after 5 cycles at 650°C, the methane conversion rate is 66.44%. The preparation method of the bifunctional material includes: dissolving copper salt, zirconium salt, nickel salt, and calcium salt in water, adding anhydrous citric acid, stirring until the solution becomes a gel, drying, and calcining at 650~750℃ for 3~5 hours to obtain a copper and zirconium oxide modified nickel / calcium oxide composite material.

3. The application as described in claim 2, characterized in that, The copper salt, zirconium salt, nickel salt, and calcium salt are copper nitrate, zirconium nitrate, nickel nitrate, and calcium nitrate, respectively.

4. The application as described in claim 2, characterized in that, The molar ratio of the nickel salt to the copper salt is (1~9):

1.

5. The application as described in claim 2, characterized in that, The sum of the molar amounts of the copper salt, zirconium salt, nickel salt, and calcium salt is a mol, the molar amount of the anhydrous citric acid is a mol, and the molar amount of the water is 30a~45a mol.

6. The application as described in claim 2, characterized in that, The stirring temperature is 85~100℃; the drying temperature is 120~140℃; and the drying time is 8~24 h.

7. The application as described in claim 2, characterized in that, The heating rate for calcination is 4~6 °C / min.

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