Solid base catalyst for hydrogen production by reforming natural gas steam as well as preparation method and application of solid base catalyst
By performing gadolinium doping modification and refining emulsification of nickel-potassium precursor on the mineral carrier in the hydrogen production process of water vapor reforming natural gas, the problems of high catalyst temperature, poor stability and easy carbon accumulation are solved, and low temperature is achieved High activity and selective catalytic effects, suitable for industrial applications.
Patent Information
- Application Number
- CN202411547301.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2024-12-31
AI Technical Summary
In the natural gas water vapor reforming hydrogen production process, there are problems such as high catalyst use temperature, poor stability, easy carbon deposits and easy sintering and inactivation.
By uniformly mixing the mineral support with the gadolinium-containing solution for hydrothermal reaction, doping the modified support material, and then refining and emulsifying the nickel and potassium precursors, a full mixing of the active components and the alkaline mineral support is formed to regulate the catalyst The pH and dispersion of active components improve the activity and stability of the catalyst.
It significantly reduces the use temperature of the catalyst, improves methane conversion and hydrogen selectivity, enhances the resistance to carbon deposits, reduces the reaction temperature, and is simple to operate and low cost, making it suitable for industrial production.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a solid base catalyst for hydrogen production by steam reforming of natural gas and a preparation method and application thereof. Background Art
[0002] Hydrogen is the clean and efficient fuel and energy carrier of the future. In recent years, people have become increasingly aware of the importance of hydrogen energy. Fossil fuels produce carbon dioxide, sulfur oxides, nitrogen oxides, etc. during use, leading to global warming, and hydrogen shows great potential in improving energy security and reducing greenhouse gas emissions. In the industrial field, hydrogen is an important component of chemical raw material synthesis gas. According to the latest statistics, the global use of hydrogen is mainly concentrated in the two aspects of hydrogenation refining and synthetic ammonia in chemical plants, and the demand for hydrogen is growing; emerging markets represented by the application of fuel cells, that is, the automotive industry that uses hydrogen as fuel in the future, may have a large demand for hydrogen.
[0003] Among the many ways to produce hydrogen, natural gas steam reforming is the most important way to produce hydrogen and synthesis gas on a large scale. It is a simple, economical and clean method for producing hydrogen and has been widely used in large-scale industrial hydrogen production, accounting for more than 40% of the world's hydrogen production. However, the natural gas steam reforming hydrogen production process still has problems in industrial applications, such as high catalyst operating temperature, poor catalyst thermal stability, easy carbon deposition and sintering deactivation. Summary of the invention
[0004] The present invention is proposed to solve the problems of high catalyst operating temperature, poor stability, easy carbon deposition and sintering deactivation in the existing natural gas steam reforming hydrogen production reaction process, and its purpose is to provide a natural gas steam reforming hydrogen production solid base catalyst and its preparation method and application.
[0005] The present invention is achieved through the following technical solutions:
[0006] A method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas comprises the following steps:
[0007] (I) uniformly mixing a mineral carrier and a gadolinium-containing solution to prepare a carrier slurry, subjecting the carrier slurry to a hydrothermal reaction, and spray-drying the slurry after the hydrothermal reaction to obtain a gadolinium-doped and modified carrier material powder;
[0008] (II) preparing a mixed solution of a molding aid, a nickel precursor and a potassium precursor, and performing a refinement and homogenization emulsification treatment on the mixed solution to obtain a mixed slurry;
[0009] (III) Adding the carrier material powder obtained in step (I) to the mixed slurry obtained in step (II), stirring and kneading the mixture thoroughly until it becomes a plastic body, extruding the plastic body into a shape, curing it in a sealed container, and then drying and calcining it to obtain a natural gas steam reforming hydrogen production catalyst.
[0010] In the above technical solution, the mineral carrier is any one or more of hydrotalcite, perovskite, dolomite, attapulgite or olivine; the solute of the gadolinium-containing solution is any one or more of gadolinium diacid, gadolinium sulfate octahydrate or gadolinium chelate; and the solvent of the gadolinium-containing solution is deionized water.
[0011] In the above technical scheme, the mass fraction of the gadolinium solution in step (I) is 0.01% to 1%; the mass fraction of the gadolinium solution in step (I) is 0.01% to 1%; the mass fraction of the gadolinium element in the obtained gadolinium element-doped and modified carrier material powder is 0.1% to 3.0%; and the solid content of the carrier slurry is 8% to 15%.
[0012] In the above technical scheme, the conditions of the hydrothermal reaction in step (I) are: reacting at 50°C to 200°C for 5h to 72h; and the spray drying is carried out using a pressure spray dryer or a centrifugal spray dryer.
[0013] In the above technical scheme, the molding aid is kaolin and / or bentonite; the nickel precursor is any one or two of nickel nitrate, nickel acetate, nickel hydroxide and nickel carbonate; the potassium precursor is any one or two of potassium nitrate, potassium acetate, potassium hydroxide and potassium carbonate; the mass of the molding aid in the mixed slurry is 5 to 15% of the mass of the gadolinium-doped and modified support material obtained in step (I); the molar ratio of nickel to potassium in the mixed slurry is 10:1.
[0014] In the above technical solution, the mass fraction of the nickel precursor in the mixed slurry is 1% to 20%.
[0015] In the above technical scheme, the refinement and homogenization emulsification treatment equipment in step (II) adopts any one or more of colloid mill, high-pressure jet mill, stirring mill or sand mill for treatment; the average particle size of the mixed slurry in step (II) is 0.1μm to 2μm.
[0016] In the above technical solution, the mass ratio of the mixed slurry to the carrier material powder in step (III) is
[0017] In the above technical scheme, the curing temperature in the closed container in step (III) is 40°C to 60°C, and the curing time is 12h to 72h; the drying temperature is 100 to 120°C; the roasting temperature is 550°C to 750°C; the roasting time is 4h to 10h; and the roasting atmosphere is air.
[0018] A solid alkali catalyst for hydrogen production by steam reforming of natural gas, comprising an active component and an alkaline mineral carrier; the active component consists of Ni and K elements, accounting for 10% to 40% of the total mass of the catalyst; the alkaline mineral carrier accounts for 60% to 90% of the total mass of the catalyst.
[0019] Application of a solid base catalyst for hydrogen production by steam reforming of natural gas in hydrogen production by steam reforming of natural gas, wherein the reaction conditions for hydrogen production by steam reforming of natural gas are as follows: placing the catalyst in a fixed bed reactor, setting the pressure to 1.0-2.0 MPa, the temperature to 500-700°C, and the space velocity to 1000 h -1 ~20000h -1 , the volume ratio of H2O and CH4 is 3.0:1.
[0020] The beneficial effects of the present invention are:
[0021] The present invention provides a solid base catalyst for hydrogen production from steam reforming of natural gas and its preparation method and application. By doping and modifying the alkaline mineral carrier materials of hydrotalcite, perovskite, dolomite, attapulgite and olivine with gadolinium, the surface structure and chemical properties of the carrier materials are improved, and the catalytic activity and stability of the catalyst materials are improved; the precursors of the forming aid, nickel and potassium are refined and homogenized and emulsified, and after being kneaded evenly with the carrier material, the active components of the catalyst, the forming aid and the carrier material are fully mixed, the pH of the catalyst is regulated, the dispersibility of the active component elements is improved, and a strong catalytic synergistic effect is provided, thereby significantly improving the activity, stability and anti-carbon deposition performance of the catalyst and reducing the reaction temperature. By adopting the present invention, the catalyst has the technical advantages of low reaction temperature, high methane conversion rate and high hydrogen selectivity in the fixed bed reaction of hydrogen production from steam reforming of natural gas; the entire preparation process of the catalyst of the present invention is simple to operate, no precious metal elements are used, the catalyst production cost is low, the catalyst strength is high, the temperature resistance is good, the applicable reaction temperature range is wide, and it has good industrial production value and economic benefits. DETAILED DESCRIPTION
[0022] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below through specific implementation methods.
[0023] Example 1
[0024] 100 g of hydrotalcite and 4.35 g of gadolinium diacid are uniformly mixed in 800 g of water, subjected to hydrothermal reaction at 130° C. for 20 h, and the obtained slurry is dried in a centrifugal spray dryer to obtain powder; 10 g of kaolin, 36.6 g of nickel nitrate and 2.02 g of potassium nitrate are added to 200 g of deionized water, and then refined and homogenized and emulsified by a high-pressure jet mill to obtain a slurry with an average particle size of 0.5 μm; the powder obtained by spray drying is added to the treated slurry, and the mixture is fully mixed, stirred and kneaded until it becomes a plastic body, the plastic body is extruded into a shape, and cured at 40° C. for 10 h in a sealed container, and then dried at 120° C. and calcined at 700° C. for 6 h in an air atmosphere to obtain a natural gas steam reforming hydrogen production catalyst.
[0025] The catalyst is used in natural gas steam reforming to produce hydrogen under the following reaction conditions: pressure 1.0 MPa, temperature 650°C, volume space velocity 3000 h -1 , the volume ratio of water to natural gas is 3:1. The specific evaluation results are shown in Table 1 below.
[0026] Example 2
[0027] 110g of perovskite and 8.6g of gadolinium sulfate octahydrate are uniformly mixed in 1000g of water, and hydrothermally reacted at 110°C for 16h. The obtained slurry is dried in a centrifugal spray dryer to obtain powder; 15g of kaolin, 24.3g of nickel acetate and 1.76g of potassium hydroxide are added to 200g of deionized water, and then refined and homogenized and emulsified by a stirring mill to obtain a slurry with an average particle size of 0.8μm; the powder obtained by the above spray drying is added to the treated slurry, and the mixture is fully mixed, stirred and kneaded until it becomes a plastic body, and the plastic body is extruded and formed, and cured at 50°C for 15h in a closed container, and then dried at 100°C, and calcined at 600°C in an air atmosphere for 8h to obtain a natural gas steam reforming hydrogen production catalyst.
[0028] The catalyst is used in natural gas steam reforming to produce hydrogen under the following reaction conditions: pressure 1.5MPa, temperature 550℃, volume space velocity 7000h -1 , the volume ratio of water to natural gas is 3:1. The specific evaluation results are shown in Table 1 below.
[0029] Example 3
[0030] 100 g of dolomite and 6.5 g of gadolinium sulfate octahydrate are uniformly mixed in 700 g of water, and a hydrothermal reaction is carried out at 100° C. for 16 h. The obtained slurry is dried in a pressure spray dryer to obtain a powder; 80 g of bentonite, 15.7 g of nickel hydroxide and 3.6 g of potassium acetate are added to 200 g of deionized water, and then a refinement and homogenization emulsification treatment is carried out to obtain a slurry with an average particle size of 0.6 μm; the powder obtained by the above spray drying is added to the treated slurry, and the mixture is fully mixed, stirred and kneaded until it becomes a plastic body, and the plastic body is extruded into a shape, and cured at 60° C. for 30 h in a sealed container, and then dried at 110° C., and calcined at 650° C. for 6 h in an air atmosphere to obtain a natural gas steam reforming hydrogen production catalyst.
[0031] The catalyst is used in natural gas steam reforming to produce hydrogen under the following reaction conditions: pressure 1.5MPa, temperature 590℃, volume space velocity 10000h -1 , the volume ratio of water to natural gas is 3:1. The specific evaluation results are shown in Table 1 below.
[0032] Example 4
[0033] 120 g of attapulgite and 7.2 g of gadolinium chelate were mixed evenly in 900 g of water, subjected to hydrothermal reaction at 140° C. for 20 h, and the obtained slurry was dried in a centrifugal spray dryer to obtain powder; a certain amount of 90 g of bentonite, 15.2 g of nickel carbonate and 1.94 g of potassium carbonate were added to 200 g of deionized water, and then refined and homogenized and emulsified using a sand mill to obtain a slurry with an average particle size of 0.5 μm; the powder obtained by the above spray drying was added to the treated slurry, and the mixture was fully mixed, stirred and kneaded until it became a plastic body, the plastic body was extruded into a shape, and cured at 40° C. for 20 h in a sealed container, and then dried at 120° C. and calcined at 700° C. for 6 h in an air atmosphere to obtain a natural gas steam reforming hydrogen production catalyst.
[0034] The catalyst is used in natural gas steam reforming to produce hydrogen under the following reaction conditions: pressure 2.0 Pa, temperature 670 ° C, volume space velocity 15000 h -1 , the volume ratio of water to natural gas is 3:1. The specific evaluation results are shown in Table 1 below.
[0035] Example 5
[0036] 120 g of olivine and 8.1 g of gadolinium chelate are uniformly mixed in 100 g of water, subjected to hydrothermal reaction at 160° C. for 20 h, and the obtained slurry is dried in a centrifugal spray dryer to obtain powder; a certain amount of 12 g of kaolin, 47.6 g of nickel nitrate and 2.6 g of potassium nitrate are added to 200 g of deionized water, and then refined and homogenized and emulsified by a colloid mill to obtain a slurry with an average particle size of 0.5 μm; the powder obtained by the above spray drying is added to the treated slurry, and the mixture is fully mixed, stirred and kneaded until it becomes a plastic body, and the plastic body is extruded into a shape, and cured at 50° C. for 25 h in a sealed container, and then dried at 110° C., and calcined at 730° C. for 6 h in an air atmosphere to obtain a natural gas steam reforming hydrogen production catalyst.
[0037] The catalyst is used in natural gas steam reforming to produce hydrogen under the following reaction conditions: pressure 2.0 MPa, temperature 700°C, volume space velocity 20,000 h -1 , the volume ratio of water to natural gas is 3:1. The specific evaluation results are shown in Table 1 below.
[0038] Table 1: Evaluation results of catalysts prepared in Examples 1 to 5
[0039] Example No. Pressure, MPa Reaction temperature,℃ <![CDATA[Space velocity, h -1 > <![CDATA[H2O / CH4]]> <![CDATA[CH4 conversion rate, %]]> <![CDATA[H2 selectivity, %]]> Example 1 1.0 650 3000 3 98.3 82.4 Example 2 1.5 550 7000 3 93.7 92.1 Example 3 1.5 590 10000 3 91.1 94.7 Example 4 2.0 670 15000 3 95.6 89.7 Example 5 2.0 700 20000 3 96.4 88.5
[0040] Principle of the present invention:
[0041] The present invention uses alkaline minerals such as hydrotalcite, perovskite, dolomite, attapulgite and olivine as carriers, firstly doping and modifying the carriers with gadolinium elements, changing the physical structure and chemical properties of the surface of the catalytic carrier material, and adjusting the interaction between the carrier and the active components; then refining and homogenizing the precursors of the molding aid, nickel and potassium, and kneading them with the mineral carrier material doped and modified with the gadolinium element, so that the active components of the catalyst, the molding aid and the carrier material are fully mixed, so that the particles of each active component are evenly distributed, effectively improving the activity and stability of the catalyst and reducing the generation of carbon deposits, thereby solving the problems of high catalyst use temperature, poor stability, easy carbon deposits and easy sintering deactivation in the process of hydrogen production reaction by steam reforming of natural gas.
[0042] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.
Claims
1. A method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas, characterized in that: The following steps are involved: (I) uniformly mixing a mineral carrier and a gadolinium-containing solution to prepare a carrier slurry, subjecting the carrier slurry to a hydrothermal reaction, and spray-drying the slurry after the hydrothermal reaction to obtain a gadolinium-doped and modified carrier material powder; (II) preparing a mixed solution of a molding aid, a nickel precursor and a potassium precursor, and performing a refinement and homogenization emulsification treatment on the mixed solution to obtain a mixed slurry; (III) Adding the carrier material powder obtained in step (I) to the mixed slurry obtained in step (II), stirring and kneading the mixture thoroughly until it becomes a plastic body, extruding the plastic body into a shape, curing it in a sealed container, and then drying and calcining it to obtain a natural gas steam reforming hydrogen production catalyst.
2. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The mineral carrier is any one or more of hydrotalcite, perovskite, dolomite, attapulgite or olivine; the solute of the gadolinium-containing solution is any one or more of gadolinium diacid, gadolinium sulfate octahydrate or gadolinium chelate; and the solvent of the gadolinium-containing solution is deionized water.
3. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The mass fraction of the gadolinium solution in step (I) is 0.01% to 1%; the mass fraction of the gadolinium element in the obtained gadolinium element-doped and modified carrier material powder is 0.1% to 3.0%; the mass fraction of the mineral carrier in the carrier slurry is 8% to 15%.
4. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The conditions of the hydrothermal reaction in the step (I) are: reacting at 50°C to 200°C for 5h to 72h; the spray drying is carried out using a pressure spray dryer or a centrifugal spray dryer.
5. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The molding aid is kaolin and / or bentonite; the nickel precursor is any one or two of nickel nitrate, nickel acetate, nickel hydroxide or nickel carbonate; the potassium precursor is any one or two of potassium nitrate, potassium acetate, potassium hydroxide or potassium carbonate; The mass of the molding aid in the mixed slurry is 5-15% of the mass of the gadolinium-doped and modified carrier material obtained in step (I); the molar ratio of nickel to potassium in the mixed slurry is 10:1; The mass fraction of the nickel precursor in the mixed slurry is 1% to 20%.
6. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The refinement and homogenization emulsification treatment equipment in step (II) adopts any one or more of colloid mill, high-pressure jet mill, stirring mill or sand mill for treatment; the average particle size of the mixed slurry in step (II) is 0.1μm to 2μm.
7. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: The mass ratio of the mixed slurry to the carrier material powder in the step (III) is (0.5-3.5):
1.
8. The method for preparing a solid base catalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In the step (III), the curing temperature in the sealed container is 40°C to 60°C, and the curing time is 12h to 72h; the drying temperature is 100°C to 120°C; the roasting temperature is 550°C to 750°C; the roasting time is 4h to 10h; and the roasting atmosphere is air.
9. A solid base catalyst for hydrogen production by steam reforming of natural gas prepared by the method according to any one of claims 1 to 8, characterized in that: The catalyst comprises active components and alkaline mineral carriers; the active components consist of Ni and K elements, accounting for 10% to 40% of the total mass of the catalyst; the alkaline mineral carrier accounts for 60% to 90% of the total mass of the catalyst.
10. Use of a solid base catalyst for hydrogen production by steam reforming of natural gas prepared by the method according to any one of claims 1 to 8 in hydrogen production by steam reforming of natural gas, characterized in that: The reaction conditions for the natural gas steam reforming hydrogen production are: placing the catalyst in a fixed bed reactor, setting the pressure to 1.0-2.0 MPa, the temperature to 500° C.-700° C., and the space velocity to 1000 h -1 ~20000h -1 , the volume ratio of H2O and CH4 is 3.0:1.