Preparation method of zirconia catalyst and its application in catalytic co-production of hydrogen and carbon monoxide

Abstract

The present invention discloses a preparation method of a zirconia catalyst and its application in catalytic co-production of hydrogen and carbon monoxide, belonging to the technical field of resource recovery, and comprising the following steps: (1) dissolving a zirconium source and a complexing agent in water and stirring at a high speed to obtain a clear solution; (2) adding an alkali solution to the solution obtained in step (1) to adjust the pH of the solution, then adding a dispersant, and refluxing and stirring the obtained solution at a certain temperature for 10-12 h; (3) adding ammonium bicarbonate to the solution obtained in (2), and then transferring the solution to a crystallization kettle for crystallization at a certain temperature; (4) filtering, washing, drying and grinding the product obtained in (3) into a powder, and then putting it into a dielectric barrier discharge plasma device for treatment; (5) calcining the treated sample obtained in step (4) in a muffle furnace to obtain a zirconia catalyst. The catalyst preparation method of the present invention is simple and has a high repetition rate, and can be applied to large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of resource recovery, and particularly relates to a preparation method of a zirconia catalyst and its application in catalytic co-production of hydrogen and carbon monoxide. Background Art

[0002] Hydrogen sulfide (H2S) is a highly toxic gas with a smell of rotten eggs. In the presence of moisture, it will corrode transmission pipelines and process equipment. It is also a poison for many industrial metal-based catalysts, and the oxygen sulfide generated by its combustion is also a component causing acid rain. H2S widely exists in acid natural gas reservoirs. In addition, a large amount of H2S gas will be desulfurized during petroleum refining, coal processing and other chemical synthesis processes. Carbon dioxide (CO2) is a key greenhouse gas affecting the carbon neutrality process. The main sources of industrial CO2 include many processes such as thermal power generation, cement production, petrochemical industry, and coal chemical industry. Both will have negative impacts on society and the environment. Therefore, it is a technical problem to be solved to effectively capture the hydrogen and sulfur resources contained in H2S in a low-carbon and green way and realize the synergistic conversion of H2S and CO2.

[0003] The traditional H2S treatment technology is the Claus process, that is, converting H2S into water and elemental sulfur under high temperature (1000 - 1200 °C). This desulfurization process has limitations on the CO2 content of the raw gas, high energy consumption, large carbon emissions and is not environmentally friendly, wasting the hydrogen resources in H2S.

[0004] If the acidic gases (H2S and CO2) in the chemical industry can be directly utilized and directly converted into hydrogen and other high-value products without separation, it can not only greatly reduce the costs generated by complex separation processes, but also synergistically recover the hydrogen resources in the acidic gases. Summary of the Invention

[0005] As one aspect of the present invention, the present invention provides a preparation method of a zirconia catalyst, which includes the following steps: (1) dissolving a zirconium source and a complexing agent in water, the concentration of zirconium ions in the obtained solution is 0.05 - 0.5 mol / L, and the molar ratio of the complexing agent to the zirconium salt is (0.5 - 5):1;

[0006] (2) adjusting the pH to 6 - 9, and refluxing and stirring at 90 - 110 °C for 10 - 12 hours;

[0007] (3) adding ammonium bicarbonate, and transferring the obtained solution to a crystallization kettle for crystallization for 24 - 48 hours;

[0008] (4) filtering, washing, drying and grinding the product obtained in step (3) into powder, and putting the powder into a dielectric barrier discharge plasma device, with a discharge power of 80 - 100 W, and treating for 3 - 8 hours;

[0009] (5) Calcinate the product obtained in step (4) to obtain a zirconia catalyst;

[0010] The complexing agent is one or more of diethanolamine, triethanolamine, ethylenediaminetetraacetate, diethylenetriaminepentaacetate, citric acid, and tartaric acid;

[0011] The zirconium salt includes one of zirconium oxychloride, zirconium nitrate, or zirconyl nitrate.

[0012] As a preferred embodiment of the method for preparing the zirconia catalyst of the present invention: step (2) further includes adjusting the pH to 6-9 and then adding a dispersant, and the dispersant is one or more of cetyltrimethylammonium bromide, polyethylene glycol, sodium dodecylbenzenesulfonate, and polyvinylpyrrolidone.

[0013] As a preferred embodiment of the method for preparing the zirconia catalyst of the present invention: in step (2), the concentration of the dispersant is 0.1 wt%-5 wt%.

[0014] As a preferred embodiment of the method for preparing the zirconia catalyst of the present invention: for the crystallization, the temperature is 140-180 °C.

[0015] As a preferred embodiment of the method for preparing the zirconia catalyst of the present invention: in step (4), when putting the powder into the dielectric barrier discharge plasma device, hydrogen is introduced at a rate of 10-20 ml / min for dielectric barrier discharge.

[0016] As a preferred embodiment of the method for preparing the zirconia catalyst of the present invention: in step (5), for the calcination, the temperature is 400-900 °C, and the calcination time is 3-8 hours.

[0017] The present invention also provides the application of the catalyst prepared by the method for preparing the zirconia catalyst in the co-production of hydrogen and carbon monoxide from carbon dioxide and hydrogen sulfide.

[0018] Specifically, under an inert atmosphere, carbon dioxide and hydrogen sulfide gases are introduced, and the plasma device is turned on for reaction. The discharge power of the plasma device is 120-180 W, and the frequency is 10-30 kHz.

[0019] Specifically, the inert atmosphere includes nitrogen, the volume percentage content of hydrogen sulfide in the reaction gas is 34%-49%, the volume percentage content of carbon dioxide is 1%-16%; the volume percentage content of nitrogen is 40-50%; the reaction temperature is 120 °C-350 °C, and the space velocity is 100-2000 h -1 , and the reaction pressure is 0.1-0.3 MPa.

[0020] Advantages of the present invention: The present invention uses H2S and CO2 as raw materials. By increasing the oxygen vacancies of the zirconia catalyst, the basicity and redox ability of the catalyst are improved, thereby enhancing the dissociation ability of hydrogen sulfide. The microspherical morphology further increases the specific surface area of the catalyst, enhancing the adsorption of H2S and CO2, and thus improving the reaction conversion rate. Through the reaction of plasma synergistic zirconia catalyst, more excited state species are formed, further enhancing the conversion of H2S and CO2. The catalyst of the present invention is a microspherical zirconia rich in vacancies. The catalyst preparation process is simple, with low cost and easy for batch production. The mesoporous structure of the catalyst is beneficial to protecting the active sites and delaying the carbon deposition from clogging the catalyst pores. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Among them:

[0022] Figure 1 is a schematic diagram of the device for producing hydrogen from carbon dioxide and hydrogen sulfide according to the present invention; Figure 1 In it, 1 - reaction tube, 2 - high-voltage electrode, 3 - inlet, 4 - outlet, 5 - grounding electrode, 6 - catalyst filling cavity, 7 - heating furnace, 8 - outlet cold trap.

[0023] Figure 2 is the X-ray diffraction pattern of the zirconia catalyst in Example 4 of the present invention;

[0024] Figure 3 is the X-ray diffraction pattern of sulfur collected in the cold trap of the device for producing hydrogen from carbon dioxide and hydrogen sulfide in Example 4 of the present invention;

[0025] Figure 4 is the SEM image of the zirconia catalyst in Example 4 of the present invention;

[0026] Figure 5 is the nitrogen adsorption-desorption isotherm curve of the zirconia catalyst in Example 4 of the present invention. Detailed Embodiments

[0027] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific embodiments of the present invention in conjunction with specific embodiments.

[0028] Example 1:

[0029] Weigh 13.57 g of zirconium nitrate and dissolve it in 100 ml of water. Add 4.21 g of diethanolamine and stir at 50 °C to obtain a clear solution. Then, add sodium hydroxide solution dropwise to adjust the pH to 7. Add 2.34 g of polyethylene glycol (average molecular weight 300). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 80 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR1.

[0030] Example 2:

[0031] Weigh 9.24 g of zirconyl nitrate and dissolve it in 100 ml of water. Add 4.21 g of diethanolamine and stir at 50 °C to obtain a clear solution. Then, add sodium hydroxide solution dropwise to adjust the pH to 7. Add 2.34 g of polyethylene glycol (average molecular weight 300). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 80 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR2.

[0032] Example 3:

[0033] Weigh 12.89 g of zirconium oxychloride and dissolve it in 100 ml of water. Add 4.21 g of diethanolamine and stir at 50 °C to obtain a clear solution. Then, add sodium hydroxide solution dropwise to adjust the pH to 7. Add 2.34 g of polyethylene glycol (average molecular weight 300). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 60 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR3.

[0034] Example 4:

[0035] Weigh 12.89 g of zirconium oxychloride and dissolve it in 100 ml of water. Add 4.21 g of diethanolamine and stir at 50 °C to obtain a clear solution. Then, dropwise add sodium hydroxide solution to adjust the pH to 7. Add 2.34 g of polyethylene glycol (average molecular weight 300). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 80 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR4.

[0036] Example 5:

[0037] Weigh 12.89 g of zirconium oxychloride and dissolve it in 100 ml of water. Add 8.41 g of citric acid and stir at 50 °C to obtain a clear solution. Then, dropwise add sodium hydroxide solution to adjust the pH to 7. Add 2.34 g of polyethylene glycol (average molecular weight 300). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 80 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR5.

[0038] Example 6:

[0039] Weigh 12.89 g of zirconium oxychloride and dissolve it in 100 ml of water. Add 4.21 g of diethanolamine and stir at 50 °C to obtain a clear solution. Then, dropwise add sodium hydroxide solution to adjust the pH to 7. Add 2.34 g of polyvinylpyrrolidone (8000, K16 - 18). Subsequently, reflux at 110 °C for 12 h. After completion, add ammonium bicarbonate to the obtained solution. Then, transfer the solution to a crystallization kettle with a polytetrafluoroethylene lining and crystallize at 180 °C for 48 h. After crystallization, filter the obtained product, wash it several times, dry it, and grind it into powder. Then, place it in a dielectric barrier discharge low-temperature plasma device and treat it in a hydrogen atmosphere with a discharge power of 80 W for 6 h. Finally, calcine the obtained primary product in a muffle furnace at 400 °C for 6 h. The catalyst is named ZR6.

[0040] Comparative Example 1:

[0041] Commercial zirconia (Aladdin), named ZR7.

[0042] Comparative Example 2:

[0043] Zirconia prepared by direct calcination of zirconium nitrate. The specific preparation process is as follows: Weigh 20 g of zirconium nitrate and calcine it in a muffle furnace at 500 °C for 5 h to obtain the sample. The catalyst is named ZR8.

[0044] Place the catalysts prepared in the above examples in the reaction chamber of a reactor made of corundum. After introducing nitrogen to remove the oxygen in the reactor, introduce a mixed gas of hydrogen sulfide, carbon dioxide and nitrogen. The volume percentage of hydrogen sulfide in the mixed gas is 34%, the volume percentage of carbon dioxide is 16%, and the volume percentage of nitrogen is 50%. The flow rate of the mixed gas is 100 ml / min, the reaction temperature is 150 °C, the reaction pressure is 0.2 MPa. Connect the plasma power supply connecting the high-voltage electrode and the ground electrode, and adjust the voltage so that the input power is 180 W and the frequency is 10 kHz. The reaction results are shown in Table 1.

[0045] Table 1 Hydrogen sulfide and carbon dioxide conversion rates and the ratio of hydrogen to carbon monoxide in the product

[0046]

[0047] As can be seen from Table 1, the catalysts prepared in Examples 1 - 6 have significantly higher hydrogen sulfide conversion rates and carbon dioxide conversion rates compared to Comparative Examples 1 - 2, solving the technical problem of low carbon dioxide conversion rate, and realizing the co-production of hydrogen and carbon monoxide, reducing the molar ratio of hydrogen to carbon monoxide, that is, increasing the carbon monoxide content in the product. Among them, the catalyst prepared in Example 4 has the best catalytic effect.

[0048] Place the ZR5 catalyst in the reaction chamber of a reactor made of corundum. After introducing nitrogen to remove the oxygen in the reactor, introduce a mixed gas of hydrogen sulfide, carbon dioxide and nitrogen. The volume percentage of hydrogen sulfide in the mixed gas is 34%, the volume percentage of carbon dioxide is 16%, and the volume percentage of nitrogen in the mixed gas is 50%. The flow rate of the mixed gas is 100 ml / min, the reaction temperature is 150 °C, the reaction pressure is 0.2 MPa. Connect the plasma power supply connecting the high-voltage electrode and the ground electrode, and adjust the initial voltage to 30 kV and the frequency to 10 kHz. By adjusting the voltage to change the input power, the reaction results corresponding to different input powers are shown in Table 2.

[0049] Table 2 Reaction results corresponding to different input powers

[0050]

[0051] As can be seen from Table 2, the increase in plasma input power can improve the hydrogen sulfide conversion rate and carbon dioxide conversion rate, and reduce the molar ratio of hydrogen to carbon monoxide in the product. The optimal input power is 180 W.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An application of a zirconium oxide catalyst in catalyzing the co-production of hydrogen and carbon monoxide from carbon dioxide and hydrogen sulfide, characterized in that: The preparation method of the zirconium oxide catalyst is as follows: 12.89g of zirconium oxychloride is weighed and dissolved in 100mL of water, 4.21g of diethanolamine is added, and a clear solution is obtained by stirring at 50°C, followed by dropwise addition of a sodium hydroxide solution to adjust the pH to 7, and 2.34g of polyethylene glycol is added, wherein the average molecular weight of the polyethylene glycol is 300, and then the solution is refluxed at 110°C for 12h. After the reflux, ammonium bicarbonate is added to the obtained solution, and the solution is transferred to a crystallization kettle with a polytetrafluoroethylene liner, and crystallized at 180°C for 48h. After the crystallization, the obtained product is filtered, washed, dried and ground into powder, and then placed in a dielectric barrier discharge low-temperature plasma device for treatment under a hydrogen atmosphere with a discharge power of 80W for 6h to obtain a primary product, and finally the obtained primary product is calcined at 400°C for 6h in a muffle furnace to obtain the zirconium oxide catalyst; The zirconium oxide catalyst is placed in a reaction chamber in a reactor made of corundum material. After nitrogen is introduced to remove oxygen in the reactor, a mixed gas of hydrogen sulfide, carbon dioxide and nitrogen is introduced. The volume percentage of hydrogen sulfide in the mixed gas is 34%, the volume percentage of carbon dioxide is 16%, and the volume percentage of nitrogen is 50%. The mixed gas flow rate is 100 mL / min, the reaction temperature is 150°C, the reaction pressure is 0.2 MPa, and a plasma power supply connected to a high-voltage electrode and a grounding electrode is turned on. The voltage is adjusted so that the input power is 180 W and the frequency is 10 kHz.

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