Natural gas steam reforming hydrogen production nano-catalyst and preparation method and application thereof
By using nanocatalysts with metal and solid solution as active components, methane and water are dual activation at medium and low temperatures, the problem of high temperature and high energy consumption of the existing natural gas hydrogen production process is solved, and efficient hydrogen production and low carbon dioxide emissions are achieved.
Patent Information
- Application Number
- CN202510016693.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-05-13
AI Technical Summary
The existing natural gas hydrogen production process such as SMR requires high temperature operation, high energy consumption, low gas integral fraction of hydrogen, and high CO2 emissions, making it difficult to meet the requirements of large-scale hydrogen production.
Using nanocatalysts with metal and solid solution as active components, the dual activation of methane and water by solid solution and metal centers is achieved to realize the hydrogen production process of natural gas water vapor reforming at medium and low temperatures, and the stability of the catalyst is improved through the redox of carbon dioxide.
The hydrogen production reaction temperature is reduced, the yield of hydrogen is increased, the carbon dioxide emissions are reduced, and energy consumption is reduced.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of natural gas resource utilization, and in particular to a binder-free shaped nanocatalyst for low-temperature natural gas steam reforming hydrogen production with metal and solid solution as active components, a preparation method and an application thereof. Background Art
[0002] Energy is the material basis for the survival and development of human society and plays a vital role in the national economy. Modern energy pursues clean, efficient and pollution-free. Hydrogen energy has become one of the preferred targets for the next generation of green energy due to its high calorific value, clean products and large-scale production.
[0003] Natural gas hydrogen production technology is still the main method of hydrogen production due to its relatively low cost, accounting for 96% of the world's hydrogen production, and only 4% of hydrogen comes from water electrolysis. According to statistics, in 2020, the global production of hydrogen using natural gas accounted for 43.8%, and my country's hydrogen produced from natural gas accounted for 19% of the total annual hydrogen production.
[0004] The main methods of producing hydrogen from methane in industry include steam methane reforming (SMR), partial oxidation of methane (POM), and autothermal reforming of methane (ATR). Among them, the SMR hydrogen production process is a traditional process that has been used in industry for more than 80 years. It has mature technology and simple reaction. At present, 80% of the world's hydrogen is produced by this process, which is the lowest cost natural gas hydrogen production process. However, the SMR process is a strong endothermic reaction. The reaction requires high temperature, high energy consumption, and high requirements for reaction equipment. The hydrogen gas volume fraction obtained by the reaction is less than 80% due to the reaction equilibrium limit, and CO2 can only be discharged directly. SMR hydrogen production will emit 10-16 tons of carbon dioxide per ton of hydrogen. Due to the above reasons, the SMR process technology fails to meet the requirements of large-scale hydrogen production. Therefore, research and development of more advanced new process technologies for hydrogen production from natural gas is an important guarantee for solving the problem of cheap hydrogen sources. The new process technology should achieve breakthroughs in reducing carbon dioxide emissions and reducing energy consumption. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a natural gas steam reforming hydrogen production nanocatalyst and its preparation method and application. The catalyst can realize the hydrogen production process at medium and low temperatures through the dual activation of methane and water by the solid solution and the metal center; and the presence of carbon dioxide in the product can oxidize and reduce the solid solution active center, improve the stability of the catalyst, and improve the yield of hydrogen.
[0006] In a first aspect, the present invention provides a method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas, which is achieved by adopting the following technical scheme.
[0007] A method for preparing a nanocatalyst for hydrogen production by natural gas steam reforming comprises the following steps:
[0008] S1. Mix two or more salt solutions of Zn, Zr, Ce, Fe, Mn and W in any proportion to obtain solution A, wherein the metal ion concentration of solution A is 0.5-2.0 mol / L, then drop a precipitant into solution A, heat and stir to perform coprecipitation, and maintain the end point pH value of the precipitation solution at 6.5-7.5, and then age, filter and wash to obtain a solid solution oxide wet cake;
[0009] S2. The solid solution oxide wet filter cake and the macroporous silica gel carrier are slurried, and the precursor complexes of Ni and Co are added to obtain a mixed slurry B. The mixed slurry B is spray-formed, dried, and calcined to obtain a natural gas steam reforming hydrogen production nanocatalyst.
[0010] Furthermore, in step S1, the salt solution is selected from any one of nitrate, sulfate, chloride, and oxalate, or a combination of several of them.
[0011] Furthermore, in step S1, the precipitant is selected from any one of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, and ammonia water; and the concentration of the precipitant is 0.75 to 2.5 mol / L.
[0012] Furthermore, in step S1, the coprecipitation temperature is 50°C to 100°C, and the stirring speed is 300 to 500 revolutions per minute (rpm).
[0013] Furthermore, in step S1, the aging time is 4 to 12 hours.
[0014] Furthermore, in step S2, the specific surface area of the macroporous silica gel carrier is 350 to 500 m 2 / g, pore volume 1.2~1.4cm 3 / g, pore size 13~20nm.
[0015] Furthermore, in step S2, the mass ratio of the solid solution oxide wet filter cake to the macroporous silica gel carrier is 9:1 to 5:5.
[0016] Furthermore, in step S2, the solid solution oxide wet filter cake and the macroporous silica gel carrier are slurried with water, and the solid-liquid ratio of the obtained slurry is 1:5 to 1:10.
[0017] Furthermore, in step S2, the precursor complex of Ni and Co is a mixture of nickel nitrate and cobalt nitrate with at least one of ketoxime, EDTA or amine; the mass volume ratio of the mixture of solid solution oxide wet filter cake and macroporous silica gel carrier to the precursor complex of Ni and Co is 1-10g / ml; the ion concentrations of Ni and Co in the precursor complex solution of Ni and Co are both 0.5-5.0mol / L.
[0018] Furthermore, in step S2, the calcination temperature is 500-650°C and the time is 4-6 hours.
[0019] In a second aspect, the present invention provides a nanocatalyst for hydrogen production by steam reforming of natural gas, which is achieved by adopting the following technical solution.
[0020] A nano catalyst for hydrogen production by steam reforming of natural gas prepared by the above preparation method.
[0021] In a third aspect, the present invention provides a use of a nanocatalyst for producing hydrogen by steam reforming of natural gas, which is achieved by adopting the following technical solution.
[0022] An application of the above natural gas steam reforming hydrogen production nanocatalyst in low-temperature natural gas steam reforming hydrogen production, the low temperature range is 400-650°C.
[0023] Specifically, the natural gas steam reforming hydrogen production reaction adopts a fixed bed process, with a reaction temperature of 450-650°C, a reaction pressure of 0-1MPa, and a space velocity of 1000-18000h -1 .
[0024] This application has the following beneficial effects.
[0025] The invention has simple synthesis steps and readily available raw materials. The nanocatalyst with metal and solid solution as active components has a large number of alkaline sites and oxygen vacancies, which can adsorb and activate methane at a relatively low temperature, reduce the reaction temperature of hydrogen production by steam reforming of natural gas, and improve the yield of hydrogen. The carbon dioxide absorbed during the reaction can also be captured and reused in subsequent catalyst regeneration, achieving breakthroughs in reducing carbon dioxide emissions and energy consumption. DETAILED DESCRIPTION
[0026] The present patent application is further described below in conjunction with embodiments.
[0027] Unless otherwise specified, the experimental methods used in the following preparation examples and examples are all conventional methods; the materials, reagents, etc. used in the following preparation examples and examples are all commercially available unless otherwise specified.
[0028] Example 1
[0029] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas, comprising the following steps:
[0030] (1) Preparation of solid solution active components by coprecipitation method
[0031] Add 100 mL of deionized water into a beaker, dissolve 3.570 g of zinc nitrate hexahydrate and 20.607 g of zirconium nitrate pentahydrate in the beaker to prepare a mixed solution, heat the mixed solution to 80°C, then drop 1.5 mol / L of ammonium carbonate solution thereto, stir vigorously at 300-500 rpm, keep the pH value of the precipitation solution at 7.0, age for 6 h, filter and wash, and finally obtain a wet cake of solid solution oxide;
[0032] (2) Preparation of Nano-molded Catalysts for Hydrogen Production from Natural Gas Steam Reforming
[0033] A mixture of 100 g of the solid solution oxide wet filter cake and a commercial macroporous silica gel carrier was slurried with a solid-liquid ratio of 1:8, wherein the mass ratio of the solid solution oxide wet filter cake to the macroporous silica gel carrier was 9:1. At the same time, 100 mL of Ni and Co ethylenediamine solution was added, wherein the ion concentrations of Ni and Co were 0.6 mol / L, respectively. The mixture was fully mixed, spray-formed, dried overnight, and moved to a muffle furnace for calcination at 600°C for 6 hours to obtain a natural gas steam reforming hydrogen production nanocatalyst.
[0034] Example 2
[0035] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0036] In the process of preparing the solid solution active component by the coprecipitation method in step (1), the solid solution component is replaced with zinc nitrate hexahydrate and cerium nitrate hexahydrate. Specifically, 3.570 g of zinc nitrate hexahydrate and 20.84 g of cerium nitrate hexahydrate are dissolved in 100 mL of deionized water in a beaker to prepare a mixed solution.
[0037] Example 3
[0038] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0039] In the process of preparing the solid solution active component by the coprecipitation method in step (1), the solid solution component is replaced with zirconium nitrate pentahydrate and cerium nitrate hexahydrate. Specifically, 4.15 g of zirconium nitrate pentahydrate and 20.84 g of cerium nitrate hexahydrate are dissolved in 100 mL of deionized water in a beaker to prepare a mixed solution.
[0040] Example 4
[0041] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0042] In the process of preparing the solid solution active component by the coprecipitation method in step (1), the solid solution component is replaced with zinc nitrate hexahydrate, zirconium nitrate pentahydrate and cerium nitrate hexahydrate. Specifically, 3.570 g of zinc nitrate hexahydrate, 10.30 g of zirconium nitrate pentahydrate and 10.42 g of cerium nitrate hexahydrate are dissolved in a beaker with 100 mL of deionized water to prepare a mixed solution.
[0043] Example 5
[0044] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0045] In the process of preparing the solid solution active component by the coprecipitation method in step (1), the solid solution component is replaced with zinc nitrate hexahydrate and ferric nitrate nonahydrate. Specifically, 3.570 g of zinc nitrate hexahydrate and 19.392 g of ferric nitrate nonahydrate are dissolved in 100 mL of deionized water in a beaker to prepare a mixed solution.
[0046] Example 6
[0047] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0048] In the step (2), during the preparation of the nano-molded catalyst for hydrogen production from steam reforming of natural gas, a mixture of 100 g of a solid solution oxide wet filter cake and a commercial macroporous silica gel carrier is slurried, with a solid-liquid ratio of 1:8 and a mass ratio of the solid solution oxide wet filter cake to the macroporous silica gel carrier of 8:2. At the same time, 100 mL of Ni and Co ethylenediamine solution is added, with the ion concentrations of Ni and Co being 0.6 mol / L respectively. The mixture is fully mixed, spray-molded, dried overnight, and moved to a muffle furnace for calcination at 600° C. for 6 h to obtain a nano-molded catalyst for hydrogen production from steam reforming of natural gas.
[0049] Example 7
[0050] A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas is different from that of Example 1 in that:
[0051] In the step (2), during the preparation of the nano-molded catalyst for hydrogen production by steam reforming of natural gas, a mixture of 100 g of a solid solution oxide wet filter cake and a commercial macroporous silica gel carrier is slurried, with a solid-liquid ratio of 1:8 and a mass ratio of the solid solution oxide wet filter cake to the macroporous silica gel carrier of 7:3. At the same time, 100 mL of Ni and Co ethylenediamine solution is added, with the ion concentrations of Ni and Co being 0.6 mol / L respectively. The mixture is fully mixed, spray-molded, dried overnight, and moved to a muffle furnace for calcination at 600° C. for 6 h to obtain a nano-molded catalyst for hydrogen production by steam reforming of natural gas.
[0052] Comparative Example 1
[0053] A method for preparing a catalyst for hydrogen production by steam reforming of natural gas, comprising the following steps:
[0054] (1) Preparation of solid solution active components by coprecipitation method
[0055] Add 100 mL of deionized water to a beaker to dissolve 3.570 g of zinc nitrate hexahydrate and 20.607 g of zirconium nitrate pentahydrate in the beaker to prepare a mixed solution, then heat the mixed solution to 80°C, and then drop 1.5 mol / L of ammonium carbonate solution thereto, stir vigorously, keep the pH value of the precipitation solution at 7.0, age for 6 hours, filter and wash, dry at 100°C for 12 hours, and calcine at 600°C for 6 hours to finally obtain a solid solution oxide;
[0056] (2) Preparation method of shaped nanocatalyst for hydrogen production by natural gas steam reforming
[0057] 20 g of macroporous silica gel was impregnated in 100 mL of ethylenediamine solution of Ni and Co, with the ion concentrations of Ni and Co being 0.6 mol / L respectively. After 4 hours, the solution was filtered, dried at 110°C, and calcined at 550°C for 4 hours to obtain a Ni-Co / SiO2 carrier.
[0058] (3) The solid solution oxide obtained in step (1) and the Ni-Co / SiO2 carrier obtained in step (2) are extruded to obtain a nanocatalyst for hydrogen production by steam reforming of natural gas.
[0059] Performance Evaluation
[0060] A 10mL micro fixed bed reactor was used to evaluate the hydrogen production reaction of natural gas steam reforming. 1g of the catalyst prepared in Examples 1-7 and Comparative Example 1 was weighed and mixed with 2mL of quartz sand and loaded into the constant temperature section of the reaction tube. Quartz sand and quartz wool were used to fill both ends, and nitrogen was continuously introduced for purging. After the temperature was raised to the required reaction temperature of 600°C and maintained for 30min to activate the catalyst, the reaction gas was introduced again. The feed volume ratio of methane and water vapor was 1:4, the anti-methane flow rate was 20mL / min, the water pump speed was 0.064mL / min, the carrier gas nitrogen was 30mL / min, and the reaction pressure was 3MPa. Analysis began 30min after the start of the reaction to ensure that the reaction started to run stably. After that, product analysis was performed using online gas chromatography every 1h. The experimental results are shown in Table 1 below:
[0061] Table 1 Experimental results of catalytic performance of various catalysts under the same reaction conditions
[0062]
[0063]
[0064] From the reaction results, under the same reaction conditions, the catalysts used in Examples 1-7 can achieve a CH4 conversion rate of more than 70% and a H2 yield of more than 70%, and the reaction performance is good. However, the catalyst used in Comparative Example 1 has a poor reaction effect, with a CH4 conversion rate of only 44% and a H2 yield of 39%. Therefore, the binder-free formed nanocatalysts for hydrogen production by steam reforming of natural gas prepared in Examples 1-7 have obvious reaction activity advantages.
[0065] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas, characterized in that: The steps include: S1. Mix two or more salt solutions of Zn, Zr, Ce, Fe, Mn and W in any proportion to obtain solution A, wherein the metal ion concentration of solution A is 0.5-2.0 mol / L, then drop a precipitant into solution A, heat and stir to perform coprecipitation, and maintain the end point pH value of the precipitation solution at 6.5-7.5, and then age, filter and wash to obtain a solid solution oxide wet cake; S2. The solid solution oxide wet filter cake and the macroporous silica gel carrier are slurried, and the precursor complexes of Ni and Co are added to obtain a mixed slurry B. The mixed slurry B is spray-formed, dried, and calcined to obtain a natural gas steam reforming hydrogen production nanocatalyst.
2. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S1, the salt solution is selected from any one of nitrate, sulfate, chloride, and oxalate, or a combination of several of them.
3. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S1, the precipitant is selected from any one of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, and ammonia water; and the concentration of the precipitant is 0.75-2.5 mol / L.
4. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S1, the coprecipitation temperature is 50°C to 100°C, and the stirring speed is 300 to 500 rpm.
5. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S2, the specific surface area of the macroporous silica carrier is 350 to 500 m 2 / g, pore volume 1.2~1.4cm 3 / g, pore size 13~20nm.
6. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S2, the mass ratio of the solid solution oxide wet filter cake to the macroporous silica gel carrier is 9:1 to 5:5; the solid solution oxide wet filter cake and the macroporous silica gel carrier are slurried, and the solid-liquid ratio of the obtained slurry is 1:5 to 1:
10.
7. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S2, the precursor complex of Ni and Co is a mixture of nickel nitrate and cobalt nitrate with at least one of ketoxime, EDTA or amine; the mass volume ratio of the mixture of solid solution oxide wet filter cake and macroporous silica gel carrier to the precursor complex of Ni and Co is 1-10g / ml; the ion concentrations of Ni and Co in the precursor complex solution of Ni and Co are both 0.5-5.0mol / L.
8. The method for preparing a nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 1, characterized in that: In step S2, the calcination temperature is 500-650°C and the calcination time is 4-6 hours.
9. A nanocatalyst for hydrogen production by steam reforming of natural gas prepared by the preparation method according to any one of claims 1 to 8.
10. An application of the nanocatalyst for hydrogen production by steam reforming of natural gas according to claim 9 in hydrogen production by steam reforming of natural gas at low temperature, characterized in that: The low temperature range is 400~650℃.