A deoxygenation catalyst, preparation method and application thereof in hydrogen purification

Abstract

The present invention provides a deoxygenation catalyst, a preparation method and an application thereof in hydrogen purification, and belongs to the field of deoxygenation catalysts. The preparation method of the deoxygenation catalyst consists of the following steps: preparing an active carrier and in-situ composite treatment. The deoxygenation catalyst, the preparation method and the application thereof in hydrogen purification of the present invention can simultaneously improve its low-temperature catalytic activity and catalytic efficiency, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, avoiding the occurrence of side reactions during the hydrogen deoxygenation process; and further improve the stability of the non-precious metal deoxygenation catalyst and improve its long-term service life.

Description

Technical Field

[0001] The present invention relates to the field of deoxygenation catalysts, and in particular to a deoxygenation catalyst, a preparation method and application thereof in hydrogen purification. Background Art

[0002] Hydrogen is a high-energy-density, zero-carbon-emission renewable energy source that can be used as a power source for fuel cells. Hydrogen production by water electrolysis is a commonly used hydrogen production process in industrial production, but the hydrogen produced by its electrolysis is usually inevitably doped with 0.3-0.6% (volume percentage) of oxygen. On the one hand, in the field of fuel cells, trace oxygen in hydrogen can cause problems such as low battery efficiency and poor stability during the operation of fuel cells. According to the ISO 14687:2019 standard issued by the ISO Hydrogen Energy Technical Committee in 2019, the oxygen content of hydrogen used in fuel cells must be limited to less than 5μL / L. On the other hand, in the field of industrial hydrogen use, trace oxygen in hydrogen will not only reduce the quality and yield of the target product, but also reduce the life of production equipment and process stability, posing a major safety hazard. Deep deoxygenation of hydrogen has become a key technical issue that needs to be solved urgently.

[0003] Existing hydrogen deoxygenation methods include physical methods and chemical methods; physical methods are usually physical adsorption methods, and chemical methods include chemical absorption methods, catalytic deoxygenation methods, etc. Among them, catalytic deoxygenation methods have comprehensive advantages such as wide application scenarios, high safety, and simple operation. It has now become the most widely used hydrogen deoxygenation method.

[0004] In the process of hydrogen deoxygenation by catalytic deoxygenation, part of the hydrogen acts as a sacrificial agent and reacts with oxygen under the catalytic action of the deoxygenation catalyst, and is separated and removed after the water is generated. Among them, the use of the deoxygenation catalyst can effectively reduce the energy barrier of the deoxygenation reaction, making hydrogen deoxygenation more economical and efficient. Existing deoxygenation catalysts generally use silicon dioxide, aluminum oxide, etc. as carriers, and precious metal catalysts made of platinum and palladium as the main active components. Although precious metal catalysts can achieve better hydrogen deoxygenation effects, the precious metal resources they use are scarce, expensive, and the cost of industrial application is high, which directly limits their large-scale industrial application; at the same time, the long-term catalytic stability of precious metal deoxygenation catalysts needs to be further improved.

[0005] Existing deoxidation catalysts with non-precious metals such as transition metals as active ingredients, although their active ingredients are easier to obtain than precious metals, the low-temperature catalytic activity and catalytic efficiency of non-precious metal deoxidation catalysts are poor, and good deoxidation catalytic performance can only be achieved under high temperature conditions; at the same time, the selectivity of non-precious metal deoxidation catalysts is poor, and side reactions are prone to occur during the hydrogen deoxidation process, directly leading to hydrogen loss. Furthermore, non-precious metal deoxidation catalysts have poor stability and are easily affected by high temperature environments, other impurities in hydrogen, etc., and have a low long-term service life.

[0006] Thus, a non-precious metal deoxygenation catalyst is provided, which can simultaneously improve its low-temperature catalytic activity and catalytic efficiency, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst to avoid the occurrence of side reactions during the hydrogen deoxygenation process; and further improve the stability of the non-precious metal deoxygenation catalyst and increase its long-term service life, which has important technical significance and research value. Summary of the invention

[0007] In order to solve the technical problems existing in the prior art, the present invention provides a deoxygenation catalyst, a preparation method and application thereof in hydrogen purification, which can simultaneously improve the low-temperature catalytic activity and catalytic efficiency of the non-precious metal deoxygenation catalyst, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, avoid the occurrence of side reactions during the hydrogen deoxygenation process; and further improve the stability of the non-precious metal deoxygenation catalyst and increase its long-term service life.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a deoxidation catalyst comprises the following steps: preparing an active carrier and in-situ composite treatment;

[0010] The method for preparing the active carrier comprises: adding copper chloride dihydrate, manganese sulfate monohydrate, and lanthanum chloride heptahydrate into deionized water, mixing them evenly, and obtaining a first solution; adding oxalic acid dihydrate into deionized water, mixing them evenly, and obtaining a second solution; dripping the second solution into the first solution at 65-70° C. under stirring conditions, and after the second solution is dripped, stirring is maintained at the temperature; separating and obtaining a solid, and washing, drying, and calcining the solid to obtain the active carrier;

[0011] The in-situ composite treatment method comprises the following steps: adding copper nitrate trihydrate and an active carrier into N,N-dimethylformamide, uniformly dispersing the mixture, and then dripping an organic ligand solution into the mixture under stirring; after the organic ligand solution is dripped, the mixture is continuously stirred to obtain a mixed material; the mixed material is placed in a sealed environment, kept at 115-120° C. for reaction, cooled, and separated to obtain a solid; and the solid is washed, dried, and calcined to obtain a deoxidation catalyst.

[0012] The organic ligand solution is a N,N-dimethylformamide solution of terephthalic acid.

[0013] Preferably, in the preparation of the active carrier, the dripping rate of the second solution is 0.8-1.1 mL / min;

[0014] The heat preservation and stirring time after the second solution is added is 90-120 minutes.

[0015] Furthermore, in the preparation of the active carrier, the calcination is carried out at a heating rate of 2-3°C / min, the temperature is raised to 580-600°C, the temperature is kept for 90-120 minutes, the temperature is further raised to 780-800°C, the temperature is kept for 4-4.5 hours, and then the temperature is cooled.

[0016] Preferably, in the preparation of the active carrier, in the first solution, the amount of deionized water added is 5.8-6.2 times the total weight of cupric chloride dihydrate, manganese sulfate monohydrate, and lanthanum chloride heptahydrate;

[0017] In the second solution, the amount of deionized water added is 19.5-20 times the weight of oxalic acid dihydrate.

[0018] Preferably, in the preparation of the active carrier, the molar ratio of cupric chloride dihydrate, manganese sulfate monohydrate, lanthanum chloride heptahydrate and oxalic acid dihydrate in the first solution and the second solution is 1-1.1:2-2.2:0.13-0.15:4-4.5.

[0019] Preferably, in the in-situ composite treatment, the dripping rate of the organic ligand solution is 0.7-0.8 mL / min;

[0020] The mass concentration of terephthalic acid in the organic ligand solution is 2-2.2wt%.

[0021] Preferably, in the in-situ composite treatment, the 115-120°C insulation reaction time is 10-12h;

[0022] The calcination is carried out in a nitrogen atmosphere at 180-190°C for 90-120 minutes and then cooled.

[0023] Preferably, in the in-situ composite treatment, the molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.02-1.05;

[0024] The weight ratio of copper nitrate trihydrate to the active carrier is 1:2.8-3.

[0025] A deoxidation catalyst is prepared by the above-mentioned preparation method.

[0026] An application of the above-mentioned deoxygenation catalyst in hydrogen purification, the hydrogen to be treated is continuously introduced into a deoxygenation reactor filled with a deoxygenation catalyst, the deoxygenation treatment temperature is controlled to be 42-45°C, the deoxygenation treatment pressure is 0.3-0.4MPa, and the hydrogen space velocity is 12000-13000h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The preparation method of the deoxidation catalyst of the present invention comprises the following steps: in the step of preparing an active carrier, copper chloride, manganese sulfate and lanthanum chloride are used in combination, and after coprecipitation under the action of oxalic acid, a lanthanum-doped composite metal oxide active carrier with a high crystallinity spinel structure is obtained by calcination; the active carrier has catalytic activity for hydrogen deoxidation, and at the same time, the pore structure of the active carrier is increased by lanthanum doping, while its structural stability is improved, more active sites are added, and the low-temperature catalytic activity and catalytic efficiency of the finally prepared deoxidation catalyst are improved, and the stability of the non-precious metal deoxidation catalyst is improved, and its long-term catalytic performance is improved; then in the in-situ composite treatment step, copper nitrate with high compatibility with the active carrier is selected, and the copper nitrate is combined with an organic ligand to realize the combination of Cu-MOF and the active carrier by in-situ composite method to obtain a deoxidation catalyst; the redox activity of the active carrier is combined with Cu-MOF by the redox activity of the active carrier and Cu-MOF. The synergistic effect of the F active sites and high porosity reduces the activation energy of the catalytic reaction, further improves the low-temperature catalytic activity and catalytic efficiency of the deoxygenation catalyst, and effectively improves the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, inhibiting the occurrence of side reactions during the hydrogen deoxygenation process; at the same time, through the thermal stability of the active carrier and the framework structure characteristics of Cu-MOF, the stability of the non-precious metal deoxygenation catalyst is further improved, while extending its long-term service life, the tolerance of the deoxygenation catalyst to impurities (such as H2S) is improved; the aforementioned technical means cooperate and synergize with each other, which can simultaneously improve its low-temperature catalytic activity and catalytic efficiency, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, avoiding the occurrence of side reactions during the hydrogen deoxygenation process; and further improve the stability of the non-precious metal deoxygenation catalyst, effectively extending its long-term service life and improving the recycling performance.

[0029] (2) The deoxygenation catalyst of the present invention is used in hydrogen purification. The hydrogen to be treated (O2 content 3000ppm) is continuously deoxygenated. The oxygen content in the deoxygenated hydrogen obtained at the 24th hour is 0.02-0.03ppm, the oxygen content in the deoxygenated hydrogen obtained at the 720th hour is 0.09-0.12ppm, and the oxygen content in the deoxygenated hydrogen obtained at the 1200th hour is 4.15-4.27ppm; and at the 1200th hour of the continuous deoxygenation treatment, the deoxygenation catalyst is not broken or powdered, and the pressure drop change rate is 3.27-3.60%.

[0030] (3) The deoxygenation catalyst of the present invention is used in the purification of hydrogen. When the hydrogen to be treated (O2 content 3000ppm) is continuously deoxygenated until the 720th hour, the H2O2 content in the deoxygenated gas without dehydration and drying is 0.38-0.41ppm, and no CO and CH4 are detected.

[0031] (4) Application of the deoxygenation catalyst of the present invention in hydrogen purification: after adding 50 ppm of H2S to the hydrogen to be treated (O2 content 3000 ppm), the deoxygenation treatment is continuously carried out using the deoxygenation catalyst. The continuous treatment time is 266-271 hours when the oxygen conversion rate is reduced to 95%. The deoxygenation catalyst is regenerated and reused in the continuous deoxygenation treatment of the hydrogen to be treated. The oxygen content in the deoxygenated hydrogen obtained at the 24th hour is 10.3-11.2 ppm. DETAILED DESCRIPTION

[0032] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described. It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] The embodiment of the present invention provides a method for preparing a deoxidation catalyst, which comprises the following steps: preparing an active carrier and performing in-situ composite treatment.

[0035] The method for preparing the active carrier comprises the following steps: adding copper chloride dihydrate, manganese sulfate monohydrate and lanthanum chloride heptahydrate into deionized water, stirring for 30-40 minutes to obtain a first solution; adding oxalic acid dihydrate into deionized water, stirring evenly to obtain a second solution; under stirring conditions, heating the first solution to 65-70° C., stirring while keeping the temperature, and dripping the second solution, and controlling the dripping rate of the second solution to 0.8-1.1 mL / min; after the second solution is dripped, keeping the temperature and stirring for 90-120 minutes, and then stirring for 15 minutes. The solid was separated by filtration; after the solid was washed with deionized water until it was neutral, it was placed in a vacuum drying oven, the vacuum degree was controlled to be 0.08-0.09MPa, and the vacuum drying was carried out at 80-85°C for 12-16h, and then the solid was evenly ground and placed in a calcining furnace, and the temperature was increased to 580-600°C at a heating rate of 2-3°C / min, and the temperature was kept for 90-120min, and then the temperature was continued to be increased to 780-800°C, and the temperature was kept for 4-4.5h, and then the solid was naturally cooled to room temperature, and the solid was ground to 90-100 mesh to obtain an active carrier.

[0036] In the preparation of the active carrier, the amount of deionized water added to the first solution is 5.8-6.2 times the total weight of cupric chloride dihydrate, manganese sulfate monohydrate, and lanthanum chloride heptahydrate;

[0037] The amount of deionized water added to the second solution is 19.5-20 times the weight of oxalic acid dihydrate;

[0038] In the first solution and the second solution used to prepare the active carrier, the molar ratio of cupric chloride dihydrate, manganese sulfate monohydrate, lanthanum chloride heptahydrate and oxalic acid dihydrate is 1-1.1:2-2.2:0.13-0.15:4-4.5.

[0039] The in-situ composite treatment method comprises the following steps: adding copper nitrate trihydrate to 60-65 times the weight of N,N-dimethylformamide, stirring for 10-20 minutes, adding an active carrier, performing ultrasonic dispersion for 20-30 minutes, and then dripping an organic ligand solution at a dripping rate of 0.7-0.8 mL / min under stirring conditions; after the organic ligand solution is dripped, stirring is continued for 40-60 minutes to obtain a mixed material; transferring the mixed material into a high-pressure reactor, sealing the high-pressure reactor, heating to 115-120° C., and maintaining the mixture at 400° C. for 2 hours. After reacting at high temperature for 10-12 hours, the mixture is naturally cooled to room temperature, the high-pressure reactor is opened and the solid is separated by filtration; the solid is washed with N,N-dimethylformamide, anhydrous ethanol and deionized water in sequence, placed in a vacuum drying oven, the vacuum degree is controlled to be 0.08-0.09MPa, and vacuum dried at 80-85°C for 12-16 hours, then ground evenly and placed in a calcining furnace, and in a nitrogen atmosphere environment, the mixture is heat-treated at 180-190°C for 90-120 minutes, then naturally cooled to room temperature, ground evenly and granulated to obtain a deoxidation catalyst.

[0040] In the in-situ composite treatment, the organic ligand solution is a solution of terephthalic acid in N,N-dimethylformamide, and the mass concentration of terephthalic acid in the organic ligand solution is 2-2.2wt%;

[0041] The molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.02-1.05;

[0042] The weight ratio of copper nitrate trihydrate to the active carrier is 1:2.8-3.

[0043] The embodiment of the present invention also provides a deoxidation catalyst prepared by the above method.

[0044] The present invention also provides an application of the deoxygenation catalyst in hydrogen purification. The hydrogen to be treated is continuously introduced into a deoxygenation reactor filled with the deoxygenation catalyst. The deoxygenation treatment temperature is controlled to be 42-45°C, the deoxygenation treatment pressure is 0.3-0.4MPa, and the hydrogen space velocity is 12000-13000h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

[0045] The present invention is further described below in conjunction with some specific embodiments.

[0046] Example 1

[0047] This embodiment provides a method for preparing a deoxidation catalyst, specifically:

[0048] 1. Preparation of active carrier

[0049] 5.12 g of copper chloride dihydrate (0.03 mol), 10.14 g of manganese sulfate monohydrate (0.06 mol), and 1.49 g of lanthanum chloride heptahydrate (0.004 mol) were added to 97.5 g of deionized water and stirred for 30 min to obtain a first solution; 15.13 g of oxalic acid dihydrate (0.12 mol) was added to 295 g of deionized water and stirred evenly to obtain a second solution; under stirring conditions, the first solution was heated to 65°C, and the second solution was added dropwise while being kept warm and stirred, and the addition of the second solution was controlled. The rate is 0.8mL / min. After the second solution is added, the mixture is kept warm and stirred for 90 minutes, and then the solid is separated by filtration. The solid is washed with deionized water until it is neutral, and then placed in a vacuum drying oven. The vacuum degree is controlled to be 0.08MPa. After being kept warm at 80°C and vacuum dried for 12 hours, the solid is ground evenly and placed in a calcining furnace. The temperature is increased to 580°C at a heating rate of 2°C / min. After being kept warm for 90 minutes, the temperature is continued to be increased to 780°C. After being kept warm for 4 hours, the solid is naturally cooled to room temperature and ground into 90 mesh to obtain an active carrier.

[0050] 2. In-situ composite treatment

[0051] 4.8 g of copper nitrate trihydrate (0.02 mol) was added to 288 g of N, N-dimethylformamide, and after stirring for 10 minutes, 13.5 g of active carrier was continuously added, and after ultrasonic dispersion for 20 minutes, the organic ligand solution was added dropwise at a dropping rate of 0.7 mL / min under stirring conditions; after the organic ligand solution was added dropwise, stirring was continued for 40 minutes to obtain a mixed material; the mixed material was transferred into a high-pressure reactor, the high-pressure reactor was sealed, the temperature was raised to 115° C., and after the reaction was kept warm for 10 hours, it was naturally cooled to room temperature, the high-pressure reactor was opened, and the solid was separated by filtration to obtain the solid; the solid was washed with N, N-dimethylformamide, anhydrous ethanol, and deionized water in sequence, and then placed in a vacuum drying oven, the vacuum degree was controlled to be 0.08 MPa, and after vacuum drying at 80° C. for 12 hours, it was ground evenly and placed in a calcining furnace, and in a nitrogen atmosphere environment, it was kept warm at 180° C. for 90 minutes, and then naturally cooled to room temperature, and granulated after being ground evenly to obtain a deoxidation catalyst.

[0052] The organic ligand solution is a N,N-dimethylformamide solution of terephthalic acid, and the mass concentration of terephthalic acid in the organic ligand solution is 2 wt %.

[0053] The molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.02.

[0054] This embodiment also provides a deoxygenation catalyst prepared by the aforementioned method.

[0055] Example 2

[0056] This embodiment provides a method for preparing a deoxidation catalyst, specifically:

[0057] 1. Preparation of active carrier

[0058] 5.46 g of copper chloride dihydrate (0.032 mol), 10.82 g of manganese sulfate monohydrate (0.064 mol), and 1.67 g of lanthanum chloride heptahydrate (0.0045 mol) were added to 108 g of deionized water and stirred for 35 minutes to obtain a first solution; 16.89 g of oxalic acid dihydrate (0.134 mol) was added to 331 g of deionized water and stirred evenly to obtain a second solution; under stirring conditions, the first solution was heated to 68°C, and the second solution was dripped into the solution while being kept warm and stirred, and the dripping rate of the second solution was controlled The temperature was 1 mL / min. After the second solution was added, the mixture was kept warm and stirred for 105 min, and then the solid was separated by filtration. The solid was washed with deionized water until neutral, and then placed in a vacuum drying oven with a vacuum degree of 0.085 MPa. After being kept warm at 82 °C and dried in vacuum for 14 h, the solid was evenly ground and placed in a calcining furnace. The temperature was raised to 590 °C at a heating rate of 2.5 °C / min. After being kept warm for 110 min, the temperature was continued to be raised to 790 °C. After being kept warm for 4.2 h, the solid was naturally cooled to room temperature and ground into 100 mesh to obtain an active carrier.

[0059] 2. In-situ composite treatment

[0060] 4.8 g of copper nitrate trihydrate (0.02 mol) was added to 298 g of N, N-dimethylformamide, and after stirring for 15 minutes, 13.9 g of active carrier was continuously added, and after ultrasonic dispersion for 25 minutes, the organic ligand solution was added dropwise at a dropping rate of 0.75 mL / min under stirring conditions; after the organic ligand solution was added dropwise, stirring was continued for 50 minutes to obtain a mixed material; the mixed material was transferred into a high-pressure reactor, the high-pressure reactor was sealed, the temperature was raised to 118° C., and after the reaction was kept warm for 11 hours, it was naturally cooled to room temperature, the high-pressure reactor was opened, and the solid was separated by filtration to obtain the solid; the solid was washed with N, N-dimethylformamide, anhydrous ethanol, and deionized water in sequence, and then placed in a vacuum drying oven, the vacuum degree was controlled to be 0.085 MPa, and after vacuum drying at 82° C. for 15 hours, it was ground evenly and placed in a calcining furnace, and in a nitrogen atmosphere environment, it was kept warm at 185° C. for 110 minutes, and then naturally cooled to room temperature, and granulated after being ground evenly to obtain a deoxidation catalyst.

[0061] The organic ligand solution is a N,N-dimethylformamide solution of terephthalic acid, and the mass concentration of terephthalic acid in the organic ligand solution is 2.1 wt %.

[0062] The molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.03.

[0063] This embodiment also provides a deoxygenation catalyst prepared by the aforementioned method.

[0064] Example 3

[0065] This embodiment provides a method for preparing a deoxidation catalyst, specifically:

[0066] 1. Preparation of active carrier

[0067] 5.63 g of copper chloride dihydrate (0.033 mol), 11.16 g of manganese sulfate monohydrate (0.066 mol), and 1.82 g of lanthanum chloride heptahydrate (0.0049 mol) were added to 115 g of deionized water and stirred for 40 min to obtain a first solution; 18.66 g of oxalic acid dihydrate (0.148 mol) was added to 373 g of deionized water and stirred evenly to obtain a second solution; under stirring conditions, the first solution was heated to 70°C, and the second solution was dripped into the solution while being kept warm and stirred, and the dripping speed of the second solution was controlled. The rate is 1.1mL / min. After the second solution is added, the mixture is kept warm and stirred for 120 minutes, and then the solid is separated by filtration. The solid is washed with deionized water until neutral, and then placed in a vacuum drying oven with a vacuum degree of 0.09MPa. After being kept warm at 85°C and dried in vacuum for 16 hours, the solid is evenly ground and placed in a calcining furnace. The temperature is increased to 600°C at a heating rate of 3°C / min, and the temperature is continued to be increased to 800°C after being kept warm for 4.5 hours, and then naturally cooled to room temperature and ground to 100 mesh to obtain an active carrier.

[0068] 2. In-situ composite treatment

[0069] 4.8 g of copper nitrate trihydrate (0.02 mol) was added to 312 g of N, N-dimethylformamide, and after stirring for 20 minutes, 14.4 g of active carrier was continuously added, and after ultrasonic dispersion for 30 minutes, the organic ligand solution was added dropwise at a dropping rate of 0.8 mL / min under stirring conditions; after the organic ligand solution was added dropwise, stirring was continued for 60 minutes to obtain a mixed material; the mixed material was transferred into a high-pressure reactor, the high-pressure reactor was sealed, the temperature was raised to 120° C., and after the reaction was kept warm for 12 hours, it was naturally cooled to room temperature, the high-pressure reactor was opened, and the solid was separated by filtration to obtain the solid; the solid was washed with N, N-dimethylformamide, anhydrous ethanol, and deionized water in sequence, and then placed in a vacuum drying oven, the vacuum degree was controlled to be 0.09 MPa, and after vacuum drying at 85° C. for 16 hours, it was ground evenly and placed in a calcining furnace, and in a nitrogen atmosphere environment, it was kept warm at 190° C. for 120 minutes, and then naturally cooled to room temperature, and granulated after being ground evenly to obtain a deoxidation catalyst.

[0070] The organic ligand solution is a N,N-dimethylformamide solution of terephthalic acid, and the mass concentration of terephthalic acid in the organic ligand solution is 2.2 wt %.

[0071] The molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.05.

[0072] This embodiment also provides a deoxygenation catalyst prepared by the aforementioned method.

[0073] Example 4

[0074] This embodiment provides the application of the above-mentioned deoxygenation catalyst in hydrogen purification, specifically: the hydrogen to be treated is continuously introduced into a deoxygenation reactor filled with a deoxygenation catalyst, the deoxygenation treatment temperature is controlled to be 42°C, the deoxygenation treatment pressure is 0.3MPa, and the hydrogen space velocity is 12000h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

[0075] Example 5

[0076] This embodiment provides the application of the aforementioned deoxygenation catalyst in hydrogen purification, specifically: the hydrogen to be treated is continuously introduced into a deoxygenation reactor filled with a deoxygenation catalyst, the deoxygenation treatment temperature is controlled to be 43°C, the deoxygenation treatment pressure is 0.35 MPa, and the hydrogen space velocity is 12500 h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

[0077] Example 6

[0078] This embodiment provides the application of the aforementioned deoxygenation catalyst in hydrogen purification, specifically: the hydrogen to be treated is continuously introduced into a deoxygenation reactor filled with a deoxygenation catalyst, the deoxygenation treatment temperature is controlled to be 45°C, the deoxygenation treatment pressure is 0.4 MPa, and the hydrogen space velocity is 13000 h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

[0079] Comparative Example 1

[0080] The preparation method of the deoxygenation catalyst of Comparative Example 1 adopts the technical scheme of Example 2. In order to contrast with the embodiment of the present invention, the technical scheme of Comparative Example 1 is changed as follows: 1) in the step of preparing the active carrier, the addition of lanthanum chloride heptahydrate is omitted; 2) the in-situ composite treatment step is omitted and modified to an impregnation adsorption treatment, specifically, 4.8g of copper nitrate trihydrate (0.02mol) is added to 100g of deionized water, mixed evenly, and an impregnation solution is obtained; then 13.9g of the active carrier is added to the impregnation solution, stirred and impregnated at room temperature for 24h, and then filtered and separated to obtain a solid. After the solid is dried, it is heat-treated at 320°C for 4h in a nitrogen environment, naturally cooled to room temperature, ground evenly and granulated to obtain the deoxygenation catalyst of Comparative Example 1.

[0081] Comparative Example 2

[0082] The preparation method of the deoxygenation catalyst of Comparative Example 2 adopts the technical scheme of Example 2. In order to contrast with the embodiment of the present invention, the technical scheme of Comparative Example 2 is changed as follows: the step of preparing the active carrier is omitted, and it is modified to an impregnation adsorption treatment. Specifically, 5.46g of cupric chloride dihydrate (0.032mol), 10.82g of manganese sulfate monohydrate (0.064mol), and 1.67g of lanthanum chloride heptahydrate (0.0045mol) are added to 108g of deionized water, mixed evenly, and an impregnation solution is obtained; then 36g of activated carbon (90 mesh) is added to the impregnation solution, stirred and impregnated at room temperature for 24h, and then filtered and separated to obtain a solid. After the solid is dried, it is heat-treated at 320°C for 4h in a nitrogen environment, naturally cooled to room temperature, and ground evenly to obtain an active carrier.

[0083] The deoxygenation catalysts of Examples 1-3 and Comparative Examples 1-2 were used respectively, and the deoxygenation catalyst of Example 6 was used in the hydrogen purification method. After the hydrogen to be treated was continuously deoxygenated, the oxygen content in the obtained deoxygenated hydrogen was detected at the 24th hour, the 720th hour, and the 1200th hour. At the same time, when the above-mentioned deoxygenation treatment was carried out to the 1200th hour, it was observed whether each deoxygenation catalyst was broken or pulverized; and the pressure drop of the hydrogen to be treated passing through the catalyst in the deoxygenation reactor at the 24th hour and the 1200th hour was recorded respectively, and the pressure drop change rate after 1200 hours of continuous deoxygenation treatment was calculated. The pressure drop change rate was calculated as follows: [(|pressure drop at the 1200th hour - pressure drop at the 24th hour|) / pressure drop at the 24th hour]×100%.

[0084] The hydrogen to be treated is desulfurized ordinary hydrogen with an O2 content of 3000ppm.

[0085] The specific results are shown in the following table:

[0086]

[0087] It can be seen that the deoxygenation catalysts of Examples 1-3 have good thermal stability at low deoxygenation treatment temperature (45°C) and high hydrogen space velocity (13000h -1) conditions, it has good low-temperature catalytic activity and catalytic efficiency, can effectively reduce the required catalytic temperature, and has a good long-term service life. In the hydrogen deoxygenation treatment for 720 hours using each deoxygenation catalyst, the oxygen content in the deoxygenated hydrogen finally obtained does not change significantly; at the same time, after the hydrogen deoxygenation treatment for 1200 hours using each deoxygenation catalyst, each deoxygenation catalyst has no breakage or pulverization, and the pressure drop change rate is ≤3.6%. Comparative Example 1 omits lanthanum chloride heptahydrate in the step of preparing the active carrier, and omits the in-situ composite treatment step, and modifies it to an impregnation adsorption treatment. The active carrier lacks the optimization effect of lanthanum on the spinel structure, and the synergistic effect of the active carrier and Cu-MOF. The low-temperature catalytic activity and long-term catalytic performance of its deoxygenation catalyst deteriorate to a certain extent, which is specifically manifested in the increase of the oxygen content of the deoxygenated hydrogen prepared by long-term hydrogen deoxygenation treatment, and the deoxygenation catalyst has broken and pulverized, and the pressure drop change rate increases significantly. In Comparative Example 2, the step of preparing the active carrier is omitted, and the activated carbon carrier is modified to be used for impregnation and adsorption treatment. The gain of the active carrier on the catalytic activity and structural stability of hydrogen deoxygenation, as well as the synergistic effect of the redox activity of the active carrier and Cu-MOF are lacking. The low-temperature catalytic activity and long-term catalytic performance of the deoxygenation catalyst are significantly deteriorated, which is specifically manifested in the increase in the oxygen content of the deoxygenated hydrogen prepared by long-term hydrogen deoxygenation treatment, the breakage and pulverization of the deoxygenation catalyst, and the significant increase in the pressure drop change rate.

[0088] Furthermore, when the above deoxygenation treatment was carried out to the 720th hour, the contents of H2O2, CO, and CH4 in the gas after deoxygenation treatment but without dehydration and drying were detected. The specific results are shown in the following table:

[0089]

[0090] It can be seen that the deoxygenation catalysts of Examples 1-3 can effectively inhibit the occurrence of side reactions during the deoxygenation of hydrogen, have good selectivity, and can still effectively inhibit the generation of side reaction products after continuous deoxygenation for 720 hours. After the relevant technical means were changed in Comparative Examples 1 and 2, the selectivity of the deoxygenation catalysts deteriorated to varying degrees, and were easily affected by impurities in hydrogen, and could not effectively inhibit the occurrence of side reactions during the deoxygenation of hydrogen; specifically, after the deoxygenation catalysts of Comparative Examples 1 and 2 were deoxygenated, the contents of H2O2, CO, and CH4 in the gas increased.

[0091] Further, 50ppm of H2S was added to the hydrogen to be treated (normal hydrogen after desulfurization), and the deoxygenation catalysts of Examples 1-3 and Comparative Examples 1-2 were used respectively, and the gas mixed with H2S was continuously deoxygenated using the deoxygenation catalyst application method of Example 6 in hydrogen purification, and the continuous treatment time when the oxygen conversion rate in the deoxygenation treatment of each catalyst was reduced to 95% was recorded; then each deoxygenation catalyst was placed in a mixed regeneration atmosphere of oxygen and nitrogen (the volume ratio of oxygen to nitrogen was 5:95), and after regeneration at 185°C for 2h, it was reused in the continuous deoxygenation treatment of the hydrogen to be treated, and the oxygen content in the obtained deoxygenated hydrogen was detected at the 24th hour of continuous treatment. The specific results are shown in the following table:

[0092]

[0093] It can be seen that the deoxygenation catalysts of Examples 1-3 have good tolerance to H2S impurities. When the hydrogen to be treated contains 50ppm H2S, the continuous treatment time can reach 266-271h when the oxygen conversion rate is reduced to 95%. At the same time, after regeneration treatment, it can still obtain good hydrogen deoxygenation performance when it is reused in hydrogen deoxygenation treatment. After the relevant technical means are changed in Comparative Examples 1 and 2, the tolerance to H2S impurities deteriorates to varying degrees, and it is easy to be poisoned and inactivated by H2S. The continuous treatment time when the oxygen conversion rate is reduced to 95% is reduced; and the hydrogen deoxygenation catalytic performance is significantly reduced after regeneration treatment.

[0094] In summary, the preparation method of the deoxygenation catalyst of the present invention comprises the following steps: in the step of preparing an active carrier, copper chloride, manganese sulfate and lanthanum chloride are used in combination, and after coprecipitation under the action of oxalic acid, a lanthanum-doped composite metal oxide active carrier with a spinel structure having a high crystallinity is obtained by calcination; the active carrier has catalytic activity for hydrogen deoxygenation, and at the same time, the pore structure of the active carrier is increased by lanthanum doping, and while its structural stability is improved, more active sites are added, which can improve the low-temperature catalytic activity and catalytic efficiency of the deoxygenation catalyst finally prepared, and improve the stability of the non-precious metal deoxygenation catalyst, and improve its long-term catalytic performance; then in the in-situ composite treatment step, copper nitrate with high compatibility with the active carrier is selected, and the copper nitrate is combined with an organic ligand to realize the combination of Cu-MOF and the active carrier by in-situ composite method, so as to obtain a deoxygenation catalyst; the redox activity of the active carrier is combined with Cu-M The synergistic effect of OF active sites and high porosity reduces the activation energy of the catalytic reaction, further improves the low-temperature catalytic activity and catalytic efficiency of the deoxygenation catalyst, and effectively improves the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, inhibiting the occurrence of side reactions during the hydrogen deoxygenation process; at the same time, through the thermal stability of the active carrier and the framework structure characteristics of Cu-MOF, the stability of the non-precious metal deoxygenation catalyst is further improved, while extending its long-term service life, the tolerance of the deoxygenation catalyst to impurities (such as H2S) is improved; the aforementioned technical means cooperate and synergize with each other, which can simultaneously improve its low-temperature catalytic activity and catalytic efficiency, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxygenation selectivity of the non-precious metal deoxygenation catalyst, avoiding the occurrence of side reactions during the hydrogen deoxygenation process; and further improve the stability of the non-precious metal deoxygenation catalyst, effectively extending its long-term service life and improving the recycling performance.

[0095] Unless otherwise specified, all percentages used in the present invention are by mass.

[0096] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a deoxidation catalyst, characterized in that: The method comprises the following steps: preparing active carrier and in-situ composite treatment; The method for preparing the active carrier comprises the following steps: adding copper chloride dihydrate, manganese sulfate monohydrate, and lanthanum chloride heptahydrate into deionized water, mixing them evenly, and obtaining a first solution; adding oxalic acid dihydrate into deionized water, mixing them evenly, and obtaining a second solution; dripping the second solution into the first solution at 65-70° C. under stirring conditions, and after the second solution is dripped, stirring the solution at the same temperature; separating and obtaining a solid, and washing, drying, and calcining the solid to obtain a lanthanum-doped composite metal oxide active carrier having a spinel structure; The in-situ composite treatment method comprises the following steps: adding copper nitrate trihydrate and an active carrier into N,N-dimethylformamide, uniformly dispersing the copper nitrate trihydrate and the active carrier, and then dropping the copper nitrate trihydrate and the active carrier into the N,N-dimethylformamide under stirring; after the organic ligand solution is added, the organic ligand solution is continued to be stirred to obtain a mixed material; the mixed material is placed in a closed environment, and after the mixture is kept at 115-120° C. for reaction, the mixture is cooled, and a solid is obtained by separation; the solid is washed, dried, and calcined to obtain a deoxidation catalyst; in the in-situ composite treatment, the Cu-MOF is combined with the active carrier by an in-situ composite method to obtain a deoxidation catalyst; The organic ligand solution is a N,N-dimethylformamide solution of terephthalic acid.

2. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the preparation of the active carrier, the dripping rate of the second solution is 0.8-1.1 mL / min; The heat preservation and stirring time after the second solution is added is 90-120 minutes.

3. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the preparation of the active carrier, the calcination is carried out at a heating rate of 2-3°C / min, the temperature is raised to 580-600°C, the temperature is kept for 90-120 minutes, the temperature is further raised to 780-800°C, the temperature is kept for 4-4.5 hours, and then the temperature is cooled.

4. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the preparation of the active carrier, in the first solution, the amount of deionized water added is 5.8-6.2 times the total weight of cupric chloride dihydrate, manganese sulfate monohydrate, and lanthanum chloride heptahydrate; In the second solution, the amount of deionized water added is 19.5-20 times the weight of oxalic acid dihydrate.

5. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the preparation of the active carrier, the molar ratio of cupric chloride dihydrate, manganese sulfate monohydrate, lanthanum chloride heptahydrate and oxalic acid dihydrate in the first solution and the second solution is 1-1.1:2-2.2:0.13-0.15:4-4.

5.

6. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the in-situ composite treatment, the drop rate of the organic ligand solution is 0.7-0.8 mL / min; The mass concentration of terephthalic acid in the organic ligand solution is 2-2.2wt%.

7. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the in-situ composite treatment, the reaction time at 115-120°C is 10-12h; The calcination is carried out in a nitrogen atmosphere at 180-190°C for 90-120 minutes and then cooled.

8. The method for preparing a deoxidation catalyst according to claim 1, characterized in that: In the in-situ composite treatment, the molar ratio of copper nitrate trihydrate to terephthalic acid in the organic ligand solution is 1:1.02-1.05; The weight ratio of copper nitrate trihydrate to the active carrier is 1:2.8-3.

9. A deoxygenation catalyst, characterized in that: The method is prepared by the method according to any one of claims 1 to 8.

10. Use of the deoxygenation catalyst according to claim 9 in hydrogen purification, characterized in that: The hydrogen to be treated is continuously introduced into the deoxygenation reactor filled with a deoxygenation catalyst, and the deoxygenation temperature is controlled at 42-45°C, the deoxygenation pressure is 0.3-0.4MPa, and the hydrogen space velocity is 12000-13000h -1 After deoxygenation treatment, dehydration and drying are carried out to continuously obtain deoxygenated hydrogen.

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