Natural Mineral-based Carbon Dioxide Treatment Materials and Their Preparation and Applications

Abstract

The present invention belongs to the field of carbon dioxide treatment, and particularly relates to a preparation method of a natural mineral-based carbon dioxide treatment material. A natural mineral containing Mg x Ca y CO3 components is subjected to two-stage gas-solid modification treatment in a hydrogen-containing atmosphere to obtain the natural mineral-based carbon dioxide treatment material; the temperature of the first stage in the two-stage gas-solid modification treatment is 240°C to 500°C, and the temperature of the second stage is 550 to 750°C; in the Mg x Ca y CO3 components, x is 0.01 to 0.9; x + y = 1. The present invention also includes the material prepared by the above preparation method and its application in carbon dioxide capture and reduction conversion. The present invention not only improves the capture and utilization rate of carbon dioxide, reduces the reaction cost, but also improves the recycling rate of natural ore as a bifunctional material, and has important engineering value and guiding significance in practical applications.

Description

Technical Field:

[0001] The present invention belongs to the technical field of industrial process waste gas purification, and particularly relates to a method for the resource utilization of carbon dioxide treatment. Background Art:

[0002] With the growth of industrialization and energy demand, the concentration of greenhouse gases in the atmosphere, especially carbon dioxide, has increased, leading to a rise in global temperatures. Carbon dioxide capture and utilization technologies are considered an economically viable technical means to reduce carbon dioxide emissions and achieve sustainable development. However, the current technologies have defects such as low carbon dioxide capture and conversion efficiency and poor material recycling performance, making it impossible to widely utilize this technology.

[0003] Regarding the above problems, some scholars have conducted extensive and in-depth research on them and made certain progress. For example, a multi-metal catalyst with a heterojunction structure is synthesized by the sol-gel method, and the reverse water gas shift reaction is carried out under experimental conditions to achieve a relatively high CO production rate and recycling performance. However, the experimental processes involved in its synthesis, such as filtration, drying, and calcination, are cumbersome, the preparation cycle is long, and the cost is relatively high, which is not conducive to large-scale industrial applications. In addition, there is also a hydrotalcite-supported catalyst prepared by the equal-volume impregnation method, which realizes the production of syngas using a non-steady-state operation under isothermal conditions, simplifies the utilization strategy of CO2, and has a certain economy. However, the selectivity of CO2 in this reaction process is relatively low, and due to the side reactions caused by the introduction of metals, the synthesis CO production rate is relatively low, and further in-depth research is still needed.

[0004] Therefore, there is an urgent need to develop a utilization method that can improve the CO2 capture and conversion performance and reduce the economic cost, solve the industrial application problem of carbon dioxide capture and utilization technologies, and promote economic feasibility and industrial transformation. Summary of the Invention:

[0005] Aiming at the problems of unsatisfactory treatment effect and high cost of existing carbon dioxide treatment materials, the present invention provides a preparation method of a natural mineral-based carbon dioxide treatment material, aiming to resourcefully prepare a natural mineral-based carbon dioxide treatment material with excellent treatment activity based on natural mineral materials.

[0006] The second object of the present invention is to provide a natural mineral-based carbon dioxide treatment material prepared by the above-mentioned preparation method.

[0007] The third object of the present invention is to provide a method for resourcefully treating carbon dioxide using the above-mentioned treatment material.

[0008] Most of the existing carbon dioxide treatment materials are prepared using analytically pure raw materials, and their process costs are relatively high. Therefore, the present invention attempts to use natural mineral-based materials with similar compositions as raw materials. However, in the early stage of research and development, it was found that due to the physical and chemical characteristics of natural mineral materials, it is difficult to obtain a carbon dioxide treatment effect similar to that of analytically pure raw materials for the carbon dioxide treatment materials prepared therefrom. In response to this problem, through in-depth research, the present invention provides the following improvement solutions:

[0009] A preparation method of a natural mineral-based carbon dioxide treatment material, comprising subjecting a natural mineral containing Mg x Ca y CO3 components to a two-stage gas-solid modification treatment in a hydrogen-containing atmosphere to obtain the natural mineral-based carbon dioxide treatment material;

[0010] The temperature of the first stage in the two-stage gas-solid modification treatment is 240°C to 500°C, and the temperature of the second stage is 550 to 750°C;

[0011] In the Mg x Ca y CO3 components, x is 0.01 to 0.9; x + y = 1.

[0012] Innovative research of the present invention shows that using raw materials in the form of Mg x Ca y CO3 double carbonate for the two-stage gas-solid treatment at the above temperatures in a hydrogen atmosphere can unexpectedly regulate the crystal structure characteristics, microstructure, and active sites; and further using the treated material for carbon dioxide capture and hydrogen conversion can effectively improve the resource conversion effect of carbon dioxide. The present invention can obtain a comparable or even better carbon dioxide resource conversion effect while reducing the treatment cost, and has great industrial value.

[0013] In the present invention, in the natural mineral, the content of the Mg x Ca y CO3 components is above 50 wt.%, preferably above 80 wt.%, and more preferably above 90 wt.%.

[0014] In the present invention, in the Mg x Ca y CO3 components, x is 0.05 to 0.5; further preferably 0.05 to 0.2.

[0015] In the present invention, in the natural mineral, elemental mineral components such as Si, Fe, Na, etc. are also allowed to exist.

[0016] In the present invention, a modified metal source is pre-compounded on a natural mineral, and then subsequent two-stage gas-solid modification treatment is carried out; the modified metal source includes a transition metal source and / or a rare earth metal source;

[0017] Preferably, the compounding method of the modified metal source is at least one of solid-phase compounding, impregnation, and precipitation.

[0018] In the present invention, the modified metal source at least includes a cerium source. Research in the present invention shows that when using a cerium source as the modification atmosphere, it has an unexpected adaptation and synergistic effect with the process of the present invention. Compared with other metal types, it can unexpectedly exhibit a synergistic effect, and better carbon dioxide capture and hydrogen reduction conversion effects can be obtained.

[0019] Preferably, the cerium source includes at least one of cerium nitrate, cerium chloride, and cerium acetylacetonate;

[0020] Preferably, the weight ratio of the modified metal element in the modified metal source to the Mg x Ca y CO3 component in the natural mineral is 0.01 - 0.3:1, more preferably 0.04 - 0.15:1, and even more preferably 0.05 - 0.1:1.

[0021] In the present invention, at least one diluent gas such as nitrogen and inert gas is allowed to exist in the hydrogen-containing gas atmosphere;

[0022] Preferably, the content of the hydrogen-containing gas atmosphere is above 10 v%, preferably above 50 v%, and further 80 v%.

[0023] In the present invention, the temperature of the first stage is 300 - 500 °C, and further 380 - 450 °C;

[0024] Preferably, the holding time at the temperature of the first stage is 0.5 - 3 h, and further 1 - 2 h.

[0025] In the present invention, the temperature of the second stage is 550 - 700 °C, and further can be 580 - 650 °C;

[0026] Preferably, the holding time at the temperature of the second stage is 0.5 - 4 h, and further 1 - 2 h.

[0027] The present invention also provides a natural mineral-based carbon dioxide treatment material prepared by the above-mentioned preparation method.

[0028] The treatment material of the present invention has special physical and chemical properties, morphology, etc. endowed by the above-mentioned preparation method, and the material prepared by the preparation method has excellent carbon dioxide capture and hydrogen reduction performance.

[0029] The present invention also provides an application of the natural mineral-based carbon dioxide treatment material prepared by the above-mentioned preparation method. As a treatment material, it is used for carbon dioxide capture and reduction conversion of waste gas containing carbon dioxide.

[0030] In the present invention, there are no special requirements for the type of waste gas containing carbon dioxide and the content of carbon dioxide.

[0031] In the application of the present invention, the waste gas containing carbon dioxide and the natural mineral-based carbon dioxide treatment material are mixed for capture treatment to obtain a carbon dioxide capture material; then, reduction conversion treatment is carried out in a hydrogen-containing atmosphere to obtain syngas containing CO.

[0032] In the present invention, there are no special requirements for the temperature in the carbon dioxide capture treatment stage, and it can be reasonably adjusted according to the treatment amount and treatment efficiency of the carbon dioxide to be treated. For example, it can be 25 - 750 °C, and further can be 600 - 700 °C.

[0033] In the present invention, the hydrogen content in the hydrogen-containing atmosphere is 30 - 100 v%, and further can be 40 - 60 v%.

[0034] In the present invention, there are no special requirements for the temperature in the reduction conversion stage, and it can be reasonably adjusted according to the treatment amount and treatment efficiency of the carbon dioxide to be treated. For example, it can be 550 - 750 °C, and further can be 600 - 700 °C.

[0035] Beneficial effects

[0036] The present invention innovatively adopts Mg x Ca y The double carbonate of CO3 is subjected to two-stage gas-solid treatment at the above temperature in a hydrogen atmosphere, which can unexpectedly regulate the crystal structure characteristics, microstructure and active sites; thereby improving the carbon dioxide capture and hydrogen conversion effects. The treatment process of the present invention is simple and has low cost, and has great industrial value.

[0037] The research of the present invention also shows that by using a metal source, especially a cerium source, to modify the natural mineral, and cooperating with the two-stage gas-solid reduction under hydrogen, it can unexpectedly achieve synergy, and better carbon dioxide capture and hydrogen reduction conversion effects can be obtained. Description of the drawings

[0038] Figure 1 XRD pattern of natural mineral 1 in Example 1;

[0039] Figure 2 XRD pattern of natural mineral 2 in Example 2;

[0040] Figure 3 XRD pattern of natural mineral 4 in Example 3. Detailed implementation mode

[0041] The present invention will be further described below in conjunction with specific embodiments. However, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The preferred implementation methods and materials described herein are for demonstration purposes. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work fall within the protection scope of the present invention.

[0042] Example 1

[0043] Step (1):

[0044] The natural mineral 1 purchased from western Hunan, Hunan (XRD is shown in Figure 1 , the chemical formula of the active ingredient is Mg 0.064 Ca 0.936 CO3, the content is 99.20 wt.%, and the other components include SiO2 and Fe2O3, with contents of 0.59 wt.% and 0.10 wt.% respectively) is ground into a powder of 60 - 200 mesh (natural mineral powder), and an in-situ CO2 capture and conversion experiment is carried out using a serial fixed bed.

[0045] 0.07 mg of quartz wool is filled in a quartz tube, and then 0.2 g of the ground natural mineral powder is placed in the quartz tube. Pure H2 gas is introduced into the quartz tube, and it is preheated to T1 (400 °C) at a heating rate of 10 °C / min for the first-stage treatment (the holding time t1 is 1 h); then it is heated to T2 (600 °C) for the second-stage treatment (the holding time t2 is 1 h).

[0046] Step (2):

[0047] After step 1, Ar is introduced while it is hot for 3 minutes of sufficient purging, and then a 10% CO2 / Ar mixed gas is continuously introduced at the above temperature for 15 minutes of CO2 capture (the temperature T' during the treatment process is 600 °C), and the total gas flow rate is controlled to 100 ml / min.

[0048] After the sample after CO2 capture is purged with Ar for 3 minutes, a 40% H2 / Ar mixed gas is introduced at the maintained temperature for the CO2 conversion reaction (the temperature T'' during the treatment process is 650 °C), the reaction time is 1 hour, and the gas medium flow rate is controlled to 100 ml / min.

[0049] Step (3):

[0050] Repeat step 2 to realize the cyclic treatment of carbon dioxide.

[0051] During the experiment, the consumed and generated gases were measured by an on-line multi-component infrared analyzer. After data processing, data such as CO2 capture amount and CO production rate could be obtained.

[0052] Reduction result: When the temperature was measured at 650 °C in the experiment, the CO production rate was 8.5 mmol g -1 , and the production rate was 8.3 mmol g after 5 cycles -1 .

[0053] Example 2

[0054] Compared with Example 1, the difference is only that the natural mineral is pre-modified. The process is as follows: The natural mineral and the modification metal source are pre-dispersed in an aqueous solution, and then the pH of the system is adjusted to 10-11. After precipitation is completed, it is dried to obtain the modified natural mineral, and then it is subjected to the two-stage thermal modification and carbon dioxide capture and conversion treatment of steps 1-3. Other operations and process parameters are the same as in Example 1. The respective case groups are:

[0055] Group A: The modification metal source is cerium nitrate; the weight ratio of Ce element to the natural mineral is 5.0 wt.%;

[0056] Group B: The modification metal source is cerium nitrate; the weight ratio of Ce element to the natural mineral is 8.8 wt.%;

[0057] Group C: The modification metal source is copper nitrate; the weight ratio of Cu element to the natural mineral is 6.4 wt.%;

[0058] Group D: The modification metal source is nickel nitrate; the weight ratio of Ni element to the natural mineral is 13.7%;

[0059] The test results are as follows:

[0060] Group A: When the temperature was measured at 650 °C in the experiment, the CO production rate was 10.9 mmol g -1 , and the production rate was 10.3 mmol g after 5 cycles -1 .

[0061] Group B: When the temperature was measured at 650 °C in the experiment, the CO production rate was 11.5 mmol g -1 , and the production rate was 10.5 mmol g after 5 cycles -1 .

[0062] Group C: When the temperature was measured at 650 °C in the experiment, the CO production rate was 10.1 mmol g -1 , and the production rate was 9.1 mmol g after 5 cycles -1 .

[0063] Group D: When the temperature was measured at 650 °C in the experiment, the CO production rate was 10.5 mmol g-1 After 5 cycles, the yield is 9.6 mmol g -1 .

[0064] Example 3

[0065] The natural mineral 2 purchased from Yantai, Shandong (XRD shown in Figure 2 , with the chemical formula Ca 0.5 Mg 0.5 CO3, with a content of 99.66 wt.%, and other components including Na2O and SiO2 with contents of 0.14 wt.% and 0.03 wt.%) was ground into a powder of 60 - 200 mesh, and then used as the natural mineral raw material for the two-stage thermal modification and carbon dioxide capture and conversion treatment in steps 1 - 3 of Example 1.

[0066] The CO2 capture and utilization experiment was carried out using the method described in Example 1. The measured CO yield was 7.8 mmol g -1 , and the yield after 5 cycles was 7.2 mmol g -1 .

[0067] Example 4

[0068] The natural mineral 3 purchased from Shijiazhuang, Hebei (XRD shown in Figure 3 , and the chemical formula of the active ingredient is Mg 0.064 Ca 0.936 CO3, with a content of 54.74 wt.%, and other components including MgO, CaO, SiO2 with contents of 44.46 wt.%, 0.58 wt.% and 0.12 wt.%) was ground into a powder of 60 - 200 mesh, and then used as the natural mineral raw material for the two-stage thermal modification and carbon dioxide capture and conversion treatment in steps 1 - 3 of Example 1.

[0069] The CO2 capture and utilization experiment was carried out using the method described in Example 1. The measured CO yield was 7.2 mmol g -1 , and the yield after 5 cycles was 6.5 mmol g -1 .

[0070] Example 5

[0071] Compared with Example 1, the difference is only that the temperature of T1 is changed to 250 °C and the heat preservation time is 1.5 h, and other operations and parameters are the same as those in Example 1.

[0072] The result is: when the temperature is 650 °C, the measured CO yield is 7.7 mmol g -1 , and the yield after 5 cycles is 7.2 mmol g -1 .

[0073] Example 6

[0074] Compared with Example 1, the only difference is that hydrogen is replaced with a hydrogen-argon atmosphere (the hydrogen content is 80 v%), the temperature of T2 is changed to 700 °C, the holding time is 2 h. In step 2, the temperature T' in the carbon dioxide capture stage is 550 °C, the hydrogen content in the hydrogen conversion stage is 50 v%, and the temperature T" of hydrogen conversion is 630 °C. Other operations and parameters are the same as in Example 1.

[0075] The result is: the CO yield is 7.8 mmol g -1 , and the yield after 5 cycles is 7.0 mmol g -1 .

[0076] Comparative Example 1

[0077] Compared with Example 1, the only difference is that the natural mineral is pre-calcined at 450-500 °C (the atmosphere is nitrogen) to pre-destroy its natural structure, and then the subsequent steps 1-3 are carried out.

[0078] It is experimentally measured that at a temperature of 650 °C, the CO yield is 4.8 mmol g -1 , and the yield after 5 cycles is 4.3 mmol g -1 .

[0079] Comparative Example 2

[0080] Compared with Example 1, the only difference is that the natural mineral is replaced with analytically pure CaCO3 and MgCO3 by physical mixing, and the Ca:Mg molar ratio is the same as in Example 1.

[0081] It is experimentally measured that at a temperature of 650 °C, the CO yield is 3.5 mmol g -1 , and the yield after 5 cycles is 3.3 mmol g -1 .

[0082] Comparative Example 3

[0083] Compared with Example 1, the only difference is that the first holding process is omitted, and other operations and parameters are the same as in Example 1.

[0084] The result is: it is experimentally measured that at a temperature of 650 °C, the CO yield is 5.2 mmol g -1 , and the yield after 5 cycles is 4.8 mmol g -1 .

[0085] Comparative Example 4

[0086] Compared with Example 1, the only difference is that in the two treatment processes of T1 and T2, hydrogen is replaced with nitrogen, and other operations and parameters are the same as in Example 1.

[0087] The results show that the CO yield is 3.3 mmol g at a temperature of 650 °C. -1 After 5 cycles, the yield was 2.9 mmolg -1 .

[0088] The above description is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by technicians familiar with the technical field within the technical scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A preparation method of a natural mineral-based carbon dioxide treatment material, characterized in that, The natural mineral containing Mg x Ca y is subjected to two-stage gas-solid modification treatment in a hydrogen-containing atmosphere to obtain the natural mineral-based carbon dioxide treatment material described above; The temperature of the first stage in the two-stage gas-solid modification treatment is 240°C to 500°C, and the temperature of the second stage is 550 to 750°C; The described Mg x Ca y In the CO3 component, the described x is 0.05 to 0.5; x + y = 1; Among the natural minerals described, the Mg x Ca y content of the CO3 component is above 50 wt.%.

2. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 1, characterized in that, Among the natural minerals described, the Mg x Ca y content of the CO3 component is 80 wt.% or more.

3. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 1, wherein Among the natural minerals described, the Mg x Ca y content of the CO3 component is above 90 wt.%.

4. The preparation method of the natural mineral-based carbon dioxide treatment material according to any one of claims 1 to 3, characterized in that, A modified metal source is pre-compounded on the natural mineral, and then the subsequent two-stage gas-solid modification treatment is carried out; the modified metal source includes a transition metal source and / or a rare earth metal source.

5. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 4, characterized in that, The compounding method of the modified metal source is at least one of solid-phase compounding, impregnation, and precipitation.

6. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 4, characterized in that, The modified metal source includes at least a cerium source.

7. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 6, characterized in that, The cerium source includes at least one of cerium nitrate, cerium chloride, and cerium acetylacetonate.

8. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 6, characterized in that, The modified metal element in the modified metal source and Mg in the natural mineral x Ca y The weight ratio of the CO3 component is 0.01 to 0.3:

1.

9. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 8, wherein, The modified metal element in the modified metal source and Mg in the natural mineral x Ca y The weight ratio of the CO3 component is 0.04 to 0.15:

1.

10. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 9, characterized in that, The modified metal element in the modified metal source and Mg in the natural mineral x Ca y The weight ratio of the CO3 component is 0.05 to 0.1:

1.

11. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 1, characterized in that, At least one diluent gas such as nitrogen and inert gas is allowed to exist in the hydrogen-containing atmosphere.

12. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 11, wherein, The content of the hydrogen-containing atmosphere is above 10 v%.

13. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 12, characterized in that, The content of the hydrogen-containing atmosphere is above 50 v%.

14. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 1, characterized in that, The temperature of the first stage is 300 to 500°C.

15. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 14, wherein, The temperature of the first stage is 380 to 450°C.

16. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 14, characterized in that, The heat preservation time at the temperature of the first stage is 0.5 to 3 h.

17. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 14, characterized in that, The heat preservation time at the temperature of the first stage is 1 to 2 h.

18. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 1, characterized in that, The temperature of the second stage is 550 to 700°C.

19. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 18, characterized in that, The temperature of the second stage is 580 to 650°C.

20. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 18, characterized in that, The heat preservation time at the temperature of the second stage is 0.5 to 4 h.

21. The preparation method of the natural mineral-based carbon dioxide treatment material according to claim 18, characterized in that, The heat preservation time at the temperature of the second stage is 1 to 2 h.

22. A natural mineral-based carbon dioxide treatment material prepared by the preparation method according to any one of claims 1 to 21.

23. Use of a natural mineral-based carbon dioxide treatment material prepared by the preparation method according to any one of claims 1 to 21, characterized in that, Using it as a treatment material for carbon dioxide capture and reduction conversion of carbon dioxide-containing waste gas.

24. The application according to claim 23, wherein, Mixing the carbon dioxide-containing waste gas and the natural mineral-based carbon dioxide treatment material for capture treatment to obtain a carbon dioxide capture material; then carrying out reduction conversion treatment in a hydrogen-containing atmosphere to obtain a syngas containing CO.

25. The application according to claim 24, characterized in that, The temperature in the carbon dioxide capture treatment stage is 25 to 750°C.

26. The application according to claim 25, characterized in that, The hydrogen content in the hydrogen-containing atmosphere is 30 to 100 v%.

27. The application according to claim 26, wherein The hydrogen content in the hydrogen-containing atmosphere is 40 to 60 v%.

28. The application according to claim 26, wherein The temperature of the reduction conversion treatment is 550 to 750°C.

Images