Method for removing carbon oxides from hydrogen and use thereof

Abstract

The present application relates to a kind of methods for removing carbon oxide in hydrogen, wherein a kind of methanation catalyst is prepared using a rotary reinforced impregnation method.The methanation catalyst prepared using the rotary reinforced impregnation method has smaller nickel particle size and nickel dispersion compared to the conventional impregnation method for preparing supported catalysts, which can effectively remove carbon oxide at high temperature and exhibit excellent catalytic activity in the methanation reaction for removing carbon oxide at low temperature, thereby reducing the energy consumption of the reaction for removing carbon oxide in hydrogen, and has broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen purification technology, specifically relating to a method for removing carbon oxides from hydrogen and its application. Background Technology

[0002] With increasingly scarce oil resources, coal conversion technologies based on Fischer-Tropsch synthesis have attracted the attention of energy giants and academia. Methanation, as the simplest reaction in Fischer-Tropsch synthesis, is mainly used in the ethylene industry, ammonia synthesis, hydrogen purification, and coal gasification, aiming to convert CO2 into CO2. x Converted to methane, or CO impurities removed from the feed gas. x This achieves the purpose of purification. Natural gas is one of the fossil fuels, mainly used in the chemical and fuel industries. Its main component, methane, can be produced from syngas (CO). x It is obtained by catalytic conversion of H2. As the simplest Fischer-Tropsch synthesis reaction, methanation has the advantages of high calorific value, high conversion rate, single product and good economic benefits.

[0003] Current industrial methanation catalysts mainly consist of Ni and Ru active components, additives, and a support, and are prepared using a traditional impregnation method. The main process involves immersing the support in a solution containing the active components for a period of time, then removing the remaining liquid using methods such as filtration and evaporation. The active components are then loaded onto the support surface as microcrystalline ions or compounds. Following this, activation processes such as drying and calcination are performed to obtain the final catalyst product. For example, Chinese patent CN103055874A discloses a methanation catalyst in which an equal amount of a water-soluble salt solution containing nickel and additives is impregnated onto an alumina support, followed by drying and calcination. Chinese patent CN102319574A also discloses a methanation catalyst, similarly using an impregnation method to load nickel onto cerium oxide-modified alumina. The main characteristics of the impregnation method are: (1) it uses a support with a pre-defined shape and size, eliminating the need for subsequent catalyst shaping operations; (2) the impregnation method can load one or more active components onto the support; and (3) the pore structure of the support basically determines the pore structure and specific surface area of ​​the resulting catalyst. However, the traditional impregnation method has the disadvantages of long impregnation equilibrium time and uneven composition, resulting in low catalytic activity for the removal of carbon oxides at low temperatures. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for removing carbon oxides from hydrogen using a methanation catalyst prepared by rotational enhanced impregnation, thereby improving the low-temperature removal conversion rate of carbon oxides.

[0005] One objective of this invention is to provide a method for removing carbon oxides from hydrogen gas, comprising the step of contacting a hydrogen-rich gas containing carbon oxides with a methanation catalyst, wherein the methanation catalyst is prepared by rotationally enhanced impregnation of a salt solution containing active components onto a support and then calcining it. Specifically, the contact reaction conditions are: a reaction temperature of 100–250°C, preferably 120–180°C; a reaction pressure of 0.1–10 MPa, preferably 1–4 MPa; and a gas space velocity of less than 5000 h⁻¹. -1 Preferably 1000-5000h -1 The concentration of carbon oxides in the inlet gas before the reaction is less than 3000 ppm, and the concentration of carbon oxides in the gas after the reaction is less than 1 ppm.

[0006] According to a specific embodiment of the present invention: In a fixed-bed reactor, a hydrogen-rich gas containing carbon oxides is contacted with a methanation catalyst with high nickel dispersion obtained by the above-mentioned rotation-enhanced impregnation method, and the reaction is carried out at a temperature of 100-250°C, a pressure of 0.1-10 MPa, and a gas space velocity of less than 5000 h⁻¹. -1 The methanation reaction was carried out under the condition that the inlet CO concentration was less than 3000 ppm, and the CO concentration in the gas after the final reaction was less than 1 ppm.

[0007] According to an embodiment of the present invention, the methanation catalyst comprises the following components, based on 100% of the total weight of the methanation catalyst:

[0008] (1) A nickel component with a nickel content of 5 to 50%, preferably, a nickel content of 10 to 45%;

[0009] (2) The auxiliary metal component has a metal content of 0.01 to 10%, preferably, the metal content of the auxiliary component is 0.1 to 1.5%;

[0010] (3) The remaining alumina carrier;

[0011] The nickel component is nickel oxide; the auxiliary metal component is selected from at least one oxide of magnesium, calcium, lanthanum, barium, and cerium.

[0012] According to an embodiment of the present invention, the preparation method of the methanation catalyst includes: using a rotation-enhanced impregnation device, using a salt solution containing nickel and auxiliary metals as the impregnation liquid, using an alumina support as the filler in a rotatable support ring, spraying the impregnation liquid onto the rotating alumina support under the action of centrifugal force, and drying and calcining to obtain the methanation catalyst.

[0013] According to a preferred embodiment of the present invention, the preparation method of the methanation catalyst specifically includes the following steps:

[0014] Step 1: Load the alumina carrier into the wire mesh carrier ring, pump the mixed salt solution containing nickel salt and auxiliary metal salt into the rotary strengthening impregnation device, and spray it evenly into the inside of the rotary packing through the liquid distributor.

[0015] Step 2: Under the action of centrifugal force, the mixed salt solution is sheared into tiny liquid micro-elements by the rotating packing material, which come into contact with the alumina support in the low-speed rotating support ring, and the impregnation is enhanced to obtain the methanation catalyst precursor, which is then dried and calcined.

[0016] Step 3: Optionally repeat the operations of Step 1 to Step 2 once or multiple times until the final methanation catalyst is obtained.

[0017] In the above method for preparing the methanation catalyst, the alumina support has a specific surface area of ​​100–300 m². 2 / g, pore volume of 0.5~1.5m 3 / g, preferably, the specific surface area of ​​the alumina carrier is 140-250m² / g. 2 / g, pore volume of 0.7~1.2m 3 / g; The alumina carrier used in this invention can be a commercially available molded alumina carrier, or it can be a commercially available alumina carrier obtained by processing. The alumina carrier obtained simply needs to meet the above-mentioned specific surface area and pore volume requirements. The processing method for commercially available alumina can involve drying at 100–120°C for 2–10 hours and calcining at 400–600°C for 2–10 hours. According to a preferred embodiment of this invention, the molded alumina carrier produced by the Beijing Chemical Research Institute is optimal.

[0018] In the above-mentioned method for preparing methanation catalyst, the nickel salt can be a water-soluble nickel salt or a nickel salt soluble in acid, preferably selected from at least one of nickel nitrate, nickel sulfate, and basic nickel carbonate; the auxiliary metal salt is selected from at least one of magnesium, calcium, lanthanum, barium, and cerium metal salts, preferably selected from at least one of magnesium, calcium, lanthanum, barium, and cerium nitrate, sulfate, or carbonate.

[0019] In the above method for preparing the methanation catalyst, step one includes:

[0020] In the mixed salt solution, the mass percentage concentration of metallic nickel is 1-15%, preferably 5-15%;

[0021] In the mixed salt solution, the mass percentage concentration of the auxiliary metal is 0.01-5%, preferably 0.1-1%;

[0022] The rotating packing is a wire mesh or cylindrical packing, such as stainless steel wire mesh packing or stainless steel cylindrical packing.

[0023] In the above-mentioned method for preparing the methanation catalyst, in step two: the rotational speed of the rotating packing is 1000-2000 rpm; the rotational speed of the support ring is 10-20 rpm; the time for enhanced impregnation is 10-30 min; the drying conditions are drying at 100-120℃ for 2-10 h; and the calcination conditions are calcination at 400-600℃ for 2-10 h.

[0024] The specific steps for preparing the above-mentioned methanation catalyst are as follows:

[0025] (1) Impregnation step: The alumina support is loaded into the wire mesh support ring. The metal salt mixed impregnation solution is pumped into the rotary enhanced impregnation device and sprayed evenly into the inner edge of the rotary packing through the liquid distributor. Under the action of high-speed centrifugal force, the impregnation solution is sheared into tiny liquid micro-elements by the rotary packing and comes into contact with the alumina support in the support ring with extremely high tangential initial velocity. The support ring rotates at low speed to ensure that the support and the impregnated liquid micro-elements are in full contact. The impregnated liquid is returned to the storage tank for liquid circulation. After a certain period of time, the methanation catalyst precursor is obtained.

[0026] (2) Drying and calcination steps: The catalyst precursor is dried and calcined to decompose it;

[0027] (3) Depending on the metal content requirements of the actual catalyst, steps (1) to (2) may be repeated once or multiple times until the final methanation catalyst is obtained.

[0028] According to a preferred embodiment of the present invention, the methanation catalyst obtained by the above preparation method is first reduced by hydrogen and then treated by nitrogen before reacting with a hydrogen-rich gas containing carbon oxides; preferably, the hydrogen reduction conditions are: reduction at 400-500°C for 2-8 hours, and the nitrogen treatment conditions are: treatment at 120-180°C for 2-8 hours; hydrogen is used to reduce part of the nickel oxide in the methanation catalyst to active nickel, and the nickel dispersion in the methanation catalyst after reduction treatment is 0.5-5%, and the nickel particle size is 10-100 nm, preferably, the nickel dispersion is 1.0-2.5%, and the nickel particle size is 20-65 nm.

[0029] The aforementioned methanation catalyst is prepared using a rotation-enhanced impregnation apparatus. Specifically, the rotation-enhanced impregnation apparatus includes a rotation-enhanced packed bed, a storage tank, and a liquid pump. The rotation-enhanced packed bed has a cylindrical structure, comprising a liquid distributor, rotating packing, and a carrier ring. The liquid distributor is located at the center of the rotation-enhanced packed bed, and rotating packing and carrier rings are arranged sequentially around the liquid distributor. The carrier rings are wire mesh carrier rings, and a certain amount of carrier particles are filled inside the carrier rings according to actual needs. A liquid outlet is provided at the lower end of the rotation-enhanced packed bed to discharge unimpregnated liquid and return it to the storage tank. The carrier rings rotate at a low speed driven by a motor, while the rotating packing rotates at a high speed driven by a motor. The impregnation liquid is pumped into the impregnation apparatus by the liquid pump and evenly sprayed into the inner side of the rotating packing through the liquid distributor. Under the action of centrifugal force, the mixed salt solution is sheared into tiny liquid micro-elements by the rotating packing, which come into contact with the alumina carrier in the low-speed rotating carrier ring. After a period of enhanced impregnation, a nickel catalyst precursor is obtained.

[0030] The second objective of this invention is to use the above-described method to remove carbon oxides from hydrogen gas.

[0031] This invention employs a rotation-enhanced impregnation method to prepare a methanation catalyst for the removal of carbon oxides from hydrogen gas. Utilizing rotational enhancement technology, a rotating packed bed is used as the methanation catalyst preparation equipment. Wire mesh or columnar packing is employed, and the impregnation solution is formed into a mist or droplets under centrifugal force, spraying onto the support surface at extremely high speeds. The highly dispersed fine droplets, extremely high initial velocity, and constantly renewing phase interface effectively increase the diffusion and permeation rate of the impregnation solution in the pores of the support, promoting the uniform adsorption of the active component on the support surface and significantly shortening the impregnation time. Finally, after drying and calcination, a methanation catalyst with high nickel component dispersion and small average nickel particle size is prepared, resulting in high activity in the low-temperature methanation reaction for the removal of carbon oxides.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] 1. The nickel component in the methanation catalyst of the present invention has high dispersion and small average particle size;

[0034] 2. The methanation catalyst of the present invention exhibits superior catalytic activity at low temperatures.

[0035] 3. The method of the present invention is used to remove carbon oxides from hydrogen gas. It can reduce the CO concentration to less than 1 ppm at a relatively low reaction temperature, which can greatly reduce energy consumption, is green and environmentally friendly, and is suitable for industrial production, with broad application prospects. Attached Figure Description

[0036] Figure 1This is a schematic diagram of a rotary hardening impregnation device. In the diagram: 1-1 is the electric motor, 1-2 is the electric motor, 1-3 is the rotary hardening packing bed, 1-4 is the liquid storage tank, 1-5 is the liquid pump, 1-6 is the liquid distributor, 1-7 is the wire mesh packing, 1-8 is the wire mesh carrier ring, 1-9 is the shaped alumina, 1-10 is the impregnation liquid inlet, and 1-11 is the impregnation liquid outlet. Detailed Implementation

[0037] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0038] The testing instruments and conditions used in this embodiment are as follows:

[0039] The specific surface area (BET) and pore volume parameters were both measured by N2 adsorption-desorption method.

[0040] The nickel component dispersion and average nickel particle size were determined by hydrogen chemisorption.

[0041] The raw materials used in the examples are from the following sources:

[0042] The molded alumina carrier was produced by Beijing Research Institute of Chemical Industry;

[0043] All other reagents used were commercially available and of analytical grade.

[0044] The rotary impregnation apparatus used in the preparation of methanation catalysts, such as Figure 1As shown, the system includes: a rotary enhanced packing bed 1-3, a liquid storage tank 1-4, a liquid pump 1-5, a motor 1-1, and a motor 1-2. The rotary enhanced packing bed 1-3 is a cylindrical structure, including a liquid distributor 1-6, rotary packing 1-7, and a wire mesh carrier ring 1-8. The center of the rotary enhanced packing bed 1-3 is the liquid distributor 1-6, which is closed at one end and has a pipe opening at the other end, connecting to the liquid pump 1-5 through a pipe. Rotary packing 1-7 and wire mesh carrier ring 1-8 are arranged in sequence around the liquid distributor 1-6. The lower end of the rotary enhanced packing bed 1-3 is provided with a liquid outlet 1-10 for discharging unimpregnated liquid and returning it to the liquid storage tank 1-4. The wire mesh carrier ring 1-8 is filled with alumina carrier 1-9, and the rotating packing 1-7 is made of stainless steel wire mesh. Motor 1 drives the carrier ring 1-8 to rotate at a low speed, and motor 2 drives the rotating packing 1-7 to rotate at a high speed. The impregnation liquid is pumped into the impregnation device by liquid pump 1-5 and evenly sprayed into the inner side of the rotating packing 1-7 by liquid distributor 1-6. Under the action of centrifugal force, the impregnation liquid is sheared into tiny liquid micro-elements by the rotating packing 1-7 and comes into contact with the alumina carrier 1-9 in the low-speed rotating carrier ring 1-8. After a period of enhanced impregnation, a nickel catalyst precursor is obtained.

[0045] Preparation Example 1

[0046] The rotation-strengthened impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​143m²). 2 / g, pore volume is 0.74m 3 The catalyst precursor (containing 15 wt% nickel and 0.5 wt% magnesium) was loaded into a wire mesh carrier ring. An impregnation solution containing nickel nitrate and magnesium nitrate (containing 15 wt% nickel and 0.5 wt% magnesium) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh carrier ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed and then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the same steps twice more to obtain a methanation catalyst with a nickel content of 39% and a magnesium content of 0.40%, denoted as A-1.

[0047] Preparation Example 2

[0048] The rotation-strengthened impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​143m²). 2 / g, pore volume is 0.74m 3The catalyst precursor (containing 15 wt% nickel and 0.5 wt% calcium) was loaded into a wire mesh carrier ring. An impregnation solution containing nickel nitrate and calcium nitrate (containing 15 wt% nickel and 0.5 wt% calcium) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh carrier ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed and then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the same steps twice more, finally yielding a methanation catalyst with a nickel content of 39% and a calcium content of 0.37%, designated A-2.

[0049] Preparation Example 3

[0050] The rotation-strengthened impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​143m²). 2 / g, pore volume is 0.74m 3 The catalyst precursor (containing 15 wt% nickel and 0.5 wt% lanthanum) was loaded into a wire mesh carrier ring. An impregnation solution containing nickel nitrate and lanthanum nitrate (containing 15 wt% nickel and 0.5 wt% lanthanum) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh carrier ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed and then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the above steps twice more, finally yielding a methanation catalyst with a nickel content of 39% and a lanthanum content of 1.14%, denoted as A-3.

[0051] Preparation Example 4

[0052] The rotation-strengthened impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​143m²). 2 / g, pore volume is 0.74m 3 The catalyst precursor (containing 15 wt% nickel and 0.5 wt% cerium) was loaded into a wire mesh carrier ring. An impregnation solution containing nickel nitrate and cerium nitrate (containing 15 wt% nickel and 0.5 wt% cerium) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh carrier ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed and then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the above steps twice more, finally yielding a methanation catalyst with a nickel content of 39% and a cerium content of 1.15%, denoted as A-4.

[0053] Preparation Example 5

[0054] The rotation-enhanced impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​193m²). 2 / g, pore volume is 0.94m3 The catalyst precursor (containing 15 wt% nickel and 0.5 wt% lanthanum) was loaded into a wire mesh support ring. An impregnation solution containing nickel nitrate and lanthanum nitrate (containing 15 wt% nickel and 0.5 wt% lanthanum) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh support ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed. It was then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the above steps twice more, finally yielding a methanation catalyst with a nickel content of 40% and a lanthanum content of 1.14%, designated A-5.

[0055] Preparation Example 6

[0056] The rotation-strengthened impregnation method was used to impregnate 50g of molded alumina carrier (produced by Beijing Research Institute of Chemical Industry, with a BET specific surface area of ​​231m²). 2 / g, pore volume 1.20m 3 The catalyst precursor (containing 15 wt% nickel and 0.5 wt% lanthanum) was loaded into a wire mesh carrier ring. An impregnation solution containing nickel nitrate and lanthanum nitrate (containing 15 wt% nickel and 0.5 wt% lanthanum) was placed in a liquid tank. The rotating packed bed was started, with the packing rotor rotating at 2000 rpm and the wire mesh carrier ring rotating at 10 rpm. The impregnation solution was pumped into the rotating bed using a horizontal pump. After 30 minutes of intensive impregnation, the catalyst precursor was removed and then dried at 120℃ for 4 hours and calcined at 600℃ for 6 hours. The resulting catalyst was subjected to the same steps twice more to obtain a methanation catalyst with a nickel content of 41% and a lanthanum content of 1.15%, designated A-6.

[0057] Comparative Example 1

[0058] Using the traditional equal-volume impregnation method, 50g of molded alumina carrier (produced by Beijing Chemical Research Institute, with a BET specific surface area of ​​143m²) was impregnated. 2 / g, pore volume is 0.74m 3 The catalyst was impregnated with a nickel nitrate / magnesium nitrate impregnation solution containing 15wt% nickel and 0.5wt% magnesium, and then dried at 100℃ for 10h and calcined at 400℃ for 10h. After repeating the impregnation, drying and calcination steps twice, a methanation catalyst with a nickel content of 39% and a magnesium content of 0.40% was finally obtained, denoted as D-1.

[0059] Test Example 1

[0060] The samples A1-9 and D1-4 were characterized by chemical pulse adsorption of hydrogen. The specific method was as follows: the samples were reduced in a hydrogen atmosphere at 450℃ for 4 hours, purged with argon at 450℃ for 2 hours, and then cooled to 45℃. At this temperature, pulse adsorption was performed with a 10% hydrogen-argon mixture. Finally, the nickel dispersion and nickel particle size of the catalyst were obtained. The results are shown in Table 1.

[0061] Table 1

[0062] catalyst Nickel content Additive content Nickel Dispersion Nickel particle size Fracture A-1 39％ Magnesium 0.40% 1.57％ 47.2nm none A-2 39％ Calcium 0.37% 1.53％ 46.7nm none A-3 39％ Lanthanum 1.14% 1.60％ 56.6nm none A-4 39％ Cerium 1.15% 1.57％ 48.3nm none A-5 40％ Lanthanum 1.14% 1.61％ 60.4nm none A-6 41％ Lanthanum 1.15% 1.62％ 62.2nm none D-1 39％ Magnesium 0.40% 0.52％ 191.8nm none

[0063] Example 1: Fixed-bed response evaluation

[0064] 10 ml of catalyst was loaded into a stainless steel fixed-bed reactor, and high-purity hydrogen was introduced at a flow rate of 300 ml / min. The reactor was heated to 450 °C to reduce the catalyst for 4 hours. Then, high-purity nitrogen was introduced at a flow rate of 300 ml / min. When the temperature dropped to the set value, feed gas with a CO content of 1000 ppm was introduced. Other conditions are listed in Table 2. The composition of the gas after the reaction was analyzed by gas chromatography using an FID detector.

[0065] Table 2

[0066]

[0067] Compared to the nickel-based catalyst in Comparative Example 1 prepared by the conventional equal-volume impregnation method, the methanation catalysts A1-6 obtained by the rotation-enhanced impregnation method in Examples 1-6 exhibit higher nickel dispersion and smaller nickel particle size. This is because the alumina support is loosely packed in the wire mesh support ring, and the rotation of the wire mesh support ring can drive the slow displacement of the support, allowing the impregnation liquid, which forms a liquid mist and droplets under centrifugal force, to be uniformly sprayed onto the support surface at extremely high speed. In addition, Table 2 shows that at reaction temperatures of 120 and 150 °C, the CO concentration after the catalytic reaction of A-1 is still below 1 ppm, while the catalytic activity of D-1 decreases with decreasing reaction temperature. This indicates that although both conventional impregnation and enhanced impregnation catalysts can completely remove carbon oxides from hydrogen under high-temperature conditions, the catalyst prepared by the enhanced impregnation method of this invention has superior activity at low temperatures. Due to the smaller nickel particle size and nickel dispersion of the enhanced impregnation methanation catalyst, it can exhibit superior catalytic activity in the low-temperature methanation reaction for removing carbon oxides.

Claims

1. A method for removing carbon oxides from hydrogen gas, comprising the step of contacting a hydrogen-rich gas containing carbon oxides with a methanation catalyst, wherein, The methanation catalyst was prepared by rotationally enhanced impregnation method, in which a salt solution containing active ingredients was loaded onto a support and then calcined. The preparation method of the methanation catalyst includes: using a rotation-enhanced impregnation device, using a salt solution containing nickel and auxiliary metals as the impregnation liquid, placing an alumina support in a rotatable support ring, and spraying the impregnation liquid onto the rotating alumina support under centrifugal force, followed by drying and calcination to obtain the methanation catalyst; the preparation method of the methanation catalyst specifically includes the following steps: Step 1: Load the alumina carrier into the wire mesh carrier ring, pump the mixed salt solution containing nickel salt and auxiliary metal salt into the rotary strengthening impregnation device, and spray it evenly into the inside of the rotary packing through the liquid distributor. Step 2: Under the action of centrifugal force, the mixed salt solution is sheared into tiny liquid micro-elements by the rotating packing material, which come into contact with the alumina support in the low-speed rotating support ring, and the impregnation is enhanced to obtain the methanation catalyst precursor, which is then dried and calcined; the rotation speed of the rotating packing material is 1000~2000 rpm; the rotation speed of the support ring is 10~20 rpm. Step 3: Optionally repeat the operations of Step 1 to Step 2 once or multiple times until the final methanation catalyst is obtained; Before reacting with hydrogen-rich gas containing carbon oxides, the obtained methanation catalyst is first reduced by hydrogen and then treated with nitrogen. In the treated methanation catalyst, the nickel dispersion is 0.5-5% and the nickel particle size is 10-100 nm.

2. The method according to claim 1, characterized in that, In the aforementioned reaction: The reaction temperature is 100~250℃; and / or, The reaction pressure is 0.1~10MPa; and / or, Gas space velocity less than 5000 h -1 ; and / or, The concentration of carbon oxides in the inlet gas before the reaction is less than 3000 ppm, and the concentration of carbon oxides in the gas after the reaction is less than 1 ppm.

3. The method according to claim 2, characterized in that, In the aforementioned reaction: The reaction temperature is 120~180℃; and / or, The reaction pressure is 1~4 MPa; and / or, Gas space velocity is 1000~5000 h⁻¹ -1 Not equal to 5000h -1 .

4. The method according to claim 1, characterized in that, Based on 100% of the total weight of the methanation catalyst, the methanation catalyst comprises the following components: (1) Nickel components with a nickel content of 5-50%; (2) The metal content of the additive is 0.01~10%; (3) The remaining alumina carrier.

5. The method according to claim 4, characterized in that, Based on 100% of the total weight of the methanation catalyst, the methanation catalyst comprises the following components: (1) Nickel components with a nickel content of 10-45%; (2) The metal content of the additive is 0.1-1.5%; (3) The remaining alumina carrier.

6. The method according to claim 4, characterized in that, The nickel component is nickel oxide; and / or, The auxiliary metal component is selected from at least one of the oxides of magnesium, calcium, lanthanum, barium, and cerium.

7. The method according to claim 1, characterized in that, In step one: The nickel salt is selected from at least one of nickel nitrate, nickel sulfate, and basic nickel carbonate; and / or, The auxiliary metal salt is selected from at least one of magnesium, calcium, lanthanum, barium, and cerium metal salts; and / or, In the mixed salt solution, the mass percentage concentration of metallic nickel is 1-15%; and / or, In the mixed salt solution, the mass percentage concentration of the auxiliary metal is 0.01~5%; and / or, The rotating packing material is either a wire mesh or a cylindrical packing material.

8. The method according to claim 7, characterized in that, In step one: The auxiliary metal salt is selected from at least one of the nitrates, sulfates, or carbonates of magnesium, calcium, lanthanum, barium, and cerium; and / or, In the mixed salt solution, the mass percentage concentration of metallic nickel is 5-15%; and / or, In the mixed salt solution, the mass percentage concentration of the auxiliary metal is 0.1% to 1%.

9. The method according to claim 1, characterized in that, In step two: The strengthening impregnation time is 10-30 minutes; and / or, The drying conditions are 100~120℃ for 2~10 hours; and / or, The calcination conditions are 400~600℃ for 2~10 hours.

10. The method according to claim 1, characterized in that, The conditions for hydrogen reduction are: reduction at 400~500℃ for 2~8 hours; and / or, The nitrogen treatment conditions are: treatment at 120~180℃ for 2~8 hours; and / or, The nickel dispersion in the treated methanation catalyst is 1.0~2.5%, and the nickel particle size is 20~65nm.

11. The application of the method according to any one of claims 1 to 10 in the removal of carbon oxides from hydrogen.

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