A hydrocarbon steam reforming catalyst and a method for preparing the same

Abstract

The application discloses a hydrocarbon steam conversion catalyst and a preparation method thereof. The method comprises the following steps: (1) a certain amount of potassium feldspar and sepiolite are soaked in a potassium hydroxide aqueous solution at a certain temperature for a certain time, then the mixture is settled, impurities are removed, and the first drying is performed to obtain a substance a; (2) the substance a and a carrier additive are mixed and formed to obtain a carrier b; (3) a lanthanum salt or a cerium salt, a cobalt salt and a certain amount of a nickel salt are dissolved to obtain an impregnation solution c, then the carrier b is placed in the impregnation solution c for a certain time, and the second drying and the first calcination are performed to obtain a mixture d; and (4) a certain amount of a ruthenium salt is used to prepare an impregnation solution e, then the mixture d is placed in the impregnation solution e for a certain time, and the third drying and the second calcination are performed to obtain the catalyst. The hydrocarbon steam catalyst provided by the application can be activated without external hydrogen supply, can be self-reduced, and has high activity and high carbon deposition resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalyst technology, in particular to a new hydrocarbon steam reforming catalyst suitable for hydrogen production device and a preparation method thereof. BACKGROUND

[0002] Hydrogen energy as a green clean energy has become an important part of the national energy strategy, and the production and effective use of hydrogen energy is the focus of research and hot spot of colleges and social research institutions. In order to meet the coming hydrogen energy era, it is urgent to develop modular hydrogen production device and its supporting catalyst. For the modular hydrocarbon steam reforming hydrogen production device, due to the high integration of the reactor, the process conditions are more stringent, and the process conditions and activity of the existing industrial catalysts cannot meet the use requirements, therefore, it is necessary to develop a high-activity conversion agent suitable for modular hydrogen production. The process flow and process parameters of the modular hydrogen production device are obviously different from those of the traditional plant hydrogen production device, and it is not simply to miniaturize the existing mature industrial hydrocarbon hydrogen production, and the catalyst, process flow, reactor, heat balance and other aspects need to be broken through and innovated. The modular device is convenient to assemble and land application, but it also faces the limitation of inconvenient supply of common materials, improving the application ability of the catalyst, and eliminating the pre-treatment activation process, which is more conducive to the popularization and application of the device. The commonly used hydrocarbon conversion catalysts are divided into two types, namely noble metal and non-noble metal. The ruthenium-based noble metal catalyst generally has high catalytic activity and good anti-carbon performance, but the price is high, while the non-noble metal catalyst nickel-based series has excellent catalytic activity and low price cost, but the nickel-based catalyst has the disadvantages of easy carbon deposition and easy sintering inactivation. How to overcome the shortcomings of various catalysts and take their advantages to apply in the modular device is the research focus. In order to adapt to various raw materials and the limitations of the modular device, it is urgent to develop a high-activity, self-reducible, and high-carbon-resistant conversion catalyst.

[0003] The patent application for invention patent CN115739065A discloses a new hydrocarbon steam conversion catalyst and a preparation method thereof, which comprises the following steps: (1) a certain amount of nickel source is dissolved in water to obtain solution A; (2) a certain amount of montmorillonite and hydrotalcite are respectively soaked in water, settled, impurities are removed, and then the dried montmorillonite and hydrotalcite are mixed to obtain mixture B; (3) mixture B is added to a potassium source, fully mixed, and then ground for a certain time to obtain mixture C; (4) mixture C is moved to a crystallization kettle, and crystallization reaction is carried out at 175-215 DEG C for 12-48 hours, then mixture D is obtained after taking out, adding a lubricant, granulating and extruding; (5) mixture D is soaked in solution A obtained in step (1) for a certain time, and then catalyst is obtained after taking out, drying and calcining; wherein in step (3), the potassium source comprises both a first potassium source and a second potassium source, wherein the first potassium source is selected from at least one of potassium aluminate and potassium metaaluminate, and the second potassium source is selected from at least one of potassium hydroxide and potassium carbonate. The catalyst is prepared by taking nickel as an active component, self-preparing potassium feldspar as an anti-carbon agent, and montmorillonite-hydrotalcite as a carrier, and the obtained catalyst needs to be reduced in a hydrogen atmosphere to have activity, which is not suitable for the case without external hydrogen supply. SUMMARY

[0004] Based on the problems of the prior art, the present application provides a hydrocarbon steam conversion catalyst and a preparation method thereof, which can be self-reduced without external hydrogen supply, and has high activity and high carbon deposition resistance.

[0005] The technical solutions provided by the present application are as follows:

[0006] The first aspect of the present application provides a preparation method of a hydrocarbon steam conversion catalyst, which comprises the following steps:

[0007] (1) a certain amount of potassium feldspar and sepiolite are soaked in a potassium hydroxide aqueous solution at a certain temperature for a certain time, settled, impurities are removed, and then material a is obtained after first drying;

[0008] (2) material a and a carrier aid are mixed and formed to obtain carrier b;

[0009] (3) lanthanum salt or cerium salt, cobalt salt are dissolved, and a certain amount of nickel salt is added to prepare impregnation liquid c, carrier b is placed in impregnation liquid c for a certain time, and then mixture d is obtained after second drying and first calcination;

[0010] Wherein, the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=Cxg / E, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions or cerium ions; A is the influence factor; g is the catalyst tortuosity factor; E is the carrier particle porosity; the value range of C is 0.3-5; the value range of g is 2.2-7; the value range of E is 1.6-2.2; the value range of A is 0.3-20.

[0011] (4) A certain amount of ruthenium salt is configured to impregnation liquid e, the mixture d is placed in the impregnation liquid e for a certain time, and then third drying and second calcination are carried out to obtain the catalyst.

[0012] Preferably, in step (1), the mass ratio of the potassium feldspar to the sepiolite is 1:4-1:8.

[0013] Preferably, in step (1), the soaking time is 180-360 min. More preferably, the soaking time is 200-300 min.

[0014] Preferably, in step (1), the soaking temperature is 200-250℃.

[0015] Preferably, in step (2), the carrier aid is at least one of polyethylene glycol, starch, and sucrose. More preferably, the carrier aid is polyethylene glycol.

[0016] Preferably, in step (2), the adhesive lubricant is nitric acid and / or citric acid.

[0017] Preferably, in step (3), the nickel salt is at least one of nickel nitrate, nickel acetate, and nickel oxalate, and the lanthanum salt or cerium salt is a soluble salt.

[0018] More preferably, in step (3), the nickel salt is nickel nitrate, and the lanthanum salt or cerium salt is a nitrate salt.

[0019] Preferably, in step (3), the mass ratio of the lanthanum salt or cerium salt: cobalt salt: nickel salt is 1:0.67:1-1:1.2:1.2.

[0020] Preferably, in step (3), the first calcination is to heat the second-dried semi-product to 180-250℃ at a speed of 1-4℃ / min, constant temperature calcination for 1-2h, then heat to 350-450℃ at a speed of 1-4℃ / min, constant temperature calcination for 2-3h; in step (4), the second calcination is to heat the third-dried semi-product to 180-200℃ at a speed of 1-4℃ / min, constant temperature calcination for 1-2h, then heat to 400-550℃ at a speed of 1-4℃ / min, constant temperature calcination for 2-3h.

[0021] Preferably, in step (4), the ruthenium salt is a water-soluble salt. More preferably, the ruthenium salt is ruthenium chloride.

[0022] The second aspect of the present application provides a hydrocarbon steam reforming catalyst prepared by the above preparation method, wherein the active components of the catalyst are distributed in multiple layers along the radial direction of the carrier, the outermost layer of the core is ruthenium, the catalyst additive is lanthanum oxide or cerium oxide, the active components in the middle layer of the shell are nickel oxide and cobalt oxide, and the core is nickel oxide; wherein the ruthenium accounts for 0.02-0.2% of the mass of the catalyst, the lanthanum oxide or cerium oxide accounts for 0.5-1.5% of the mass of the catalyst, the nickel oxide accounts for 5.5-8.5% of the mass of the catalyst, the cobalt oxide accounts for 1-3.8% of the mass of the catalyst, and the remaining components of the catalyst are the composite carrier.

[0023] The present application has at least the following advantages:

[0024] The active metal components in the hydrocarbon steam reforming catalyst of the present application are distributed in multiple layers along the radial direction of the carrier, the outermost layer of the core is ruthenium, the active metal components in the middle layer of the shell are nickel oxide and cobalt oxide, and the core is nickel oxide, forming a multi-layer structure. The outermost layer of the core provides the initial activity of the catalyst to facilitate the reforming reaction, and the hydrogen produced gradually diffuses into the interior of the catalyst to reduce the oxidized metal, thereby improving the activity of the catalyst, allowing the reforming catalyst of the modular hydrogen production device to be gradually self-reduced and activated without external hydrogen supply, achieving the purpose of environmental protection and energy saving, and meeting the use requirements of the reforming catalyst of the modular hydrogen production device.

[0025] In the kalsilite-sepiolite composite carrier of the hydrocarbon steam reforming catalyst of the present application, the active center of sepiolite converts the adsorbed organic matter into an activated complex, and the kalsilite enters the rod layer structure of sepiolite fibers, stabilizing the structure of the catalyst, and the flowing gaseous potassium base provides alkalinity, facilitating the reaction of carbon and steam, reducing the generation of carbon deposition, and the catalyst has high carbon deposition resistance.

[0026] The hydrocarbon steam reforming catalyst prepared by the present application can realize self-reduction and activation without external hydrogen when used in industrial applications, has high activity and high carbon deposition resistance, and has good economic benefits and application prospects.

[0027] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a small pressure evaluation device used in the test of the present application.

[0029] Figure 2 is a carbon content graph of the hydrocarbon steam reforming catalyst of the examples and comparative examples of the present application.

[0030] Reference Signs List

[0031] In Figure 1 , 1, oil metering pump, 2, water metering pump, 3, vaporizer, 4, mixer, 5, tubular reactor, 6, condenser, 7, separator, 8, pressure stabilizer, 9, wet flowmeter. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. The examples of the embodiments are shown in the drawings. It should be understood that the specific embodiments described in the following embodiments of the present application are only exemplary illustrations of the specific embodiments of the present application, and are intended to explain the present application, but do not constitute a limitation on the present application.

[0033] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and the values are approximate values and should be understood as including values approximately near these ranges and values within these ranges. For ranges of values, the endpoints of the ranges are combined with the individual points to form new ranges. These new ranges are to be considered as disclosed herein. In the description of the application, unless otherwise stated, the meaning of "one", "more than one" and the like similar words are two or more than two.

[0034] The first aspect of the present application provides a preparation method of a hydrocarbon steam reforming catalyst, comprising:

[0035] (1) a certain amount of potassium feldspar and sepiolite are soaked in a potassium hydroxide aqueous solution at a certain temperature for a certain time, then settled, impurities are removed, and a first drying is performed to obtain a substance a;

[0036] (2) the substance a and a carrier aid are mixed to form a carrier b;

[0037] (3) a lanthanum salt or cerium salt, a cobalt salt, and a certain amount of a nickel salt are dissolved to prepare an impregnation solution c, the carrier b is placed in the impregnation solution c for a certain time, then a second drying and a first calcination are performed to obtain a mixture d;

[0038] wherein the concentration of the impregnation solution c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=Cxg / E, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions or cerium ions; A is the influence factor; g is the catalyst tortuosity factor; E is the porosity of the carrier particles; the numerical range of C is 0.3-5; the numerical range of g is 2.2-7; the numerical range of E is 1.6-2.2; the numerical range of A is 0.3-20;

[0039] (4) A certain amount of ruthenium salt is used to prepare an impregnation solution e, the mixture d is placed in the impregnation solution e for a certain period of time, and then third drying and second calcination are performed to obtain the catalyst.

[0040] Sepiolite is a magnesium silicate clay mineral, and its theoretical chemical formula is Mg8[Si 12 O 30 ](OH)4·12H2O. There are 4 water molecules as crystal water, and the rest are zeolite water. Sepiolite belongs to a chain-layered hydrous magnesium aluminum silicate or magnesium silicate mineral of S monoclinic or orthorhombic crystal system, and has a large specific surface area to adsorb various reactants and active components of the catalyst. Since the sepiolite has alkaline and acidic centers, the reactants are easily polarized into activated complexes at the center, and the catalyst produces a synergistic catalytic effect. Sepiolite has a fibrous structure, can form a large specific surface area and inter-particle voids, has strong adsorption, and can provide more active sites, but the mechanical strength of sepiolite is poor, and the strength is not enough when used alone as a catalyst carrier, so other carriers need to be added for use together.

[0041] Potassium feldspar is used as a raw material, and potassium phlogopite is generated through the reaction process of the present application, and the potassium phlogopite-sepiolite composite carrier structure is formed in the finished product of the catalyst. In the potassium phlogopite-sepiolite composite carrier structure of the present application, the active center of sepiolite converts the adsorbed organic matter into an activated complex, and the generated potassium phlogopite enters the fibrous layer structure of sepiolite, so that the catalyst structure is stable, potassium is not easily lost at high temperature, and the flowing gaseous potassium base provides alkalinity, promotes the reaction of carbon and water vapor, reduces the generation of carbon deposition, and the catalyst has high carbon deposition resistance.

[0042] The potassium phlogopite-sepiolite composite carrier structure of the present application not only has the advantages of high potassium content and potassium in the crystal lattice that is not easily lost at high temperature, but also can play a good anti-coking effect as a catalyst or catalyst additive in a hydrogen conversion catalyst.

[0043] According to the present application, the amount of potassium feldspar and sepiolite is 1:2-1:10. In some preferred embodiments, in step (1), the mass ratio of the potassium feldspar to the sepiolite is 1:4-1:8.

[0044] According to the present application, in step (1), the concentration of the aqueous potassium hydroxide solution is 10-60wt%. In some preferred embodiments, in step (1), the concentration of the aqueous potassium hydroxide solution is 20-45wt%

[0045] According to the present application, in step (1), the soaking temperature is usually 210-260℃. In some preferred embodiments, in step (1), the soaking temperature is 220-250℃.

[0046] According to the present application, in step (1), the soaking time is usually 180-360 min. In some preferred embodiments, in step (1), the soaking time is 200-300 min.

[0047] According to the present application, in step (1), the first drying temperature is 80-150°C, preferably 90-110°C; the drying time is 240-600 min, preferably 360-550 min.

[0048] According to the present application, in step (2), the carrier aid is an organic carrier aid. In some preferred embodiments of the present application, in step (2), the carrier aid is at least one of polyethylene glycol, starch, sucrose. More preferably, the carrier aid is polyethylene glycol.

[0049] According to the present application, in step (2), the amount of the carrier aid is 1%-4% of the mass of substance a. In some preferred embodiments, in step (2), the amount of the carrier aid is 2%-3.5% of the mass of substance a.

[0050] According to the present application, the raw material of carrier b further comprises a binding lubricant, which has no negative effect on the catalyst preparation process and catalyst performance, and can promote the formation of inorganic acid and / or organic acid, such as at least one of nitric acid, citric acid, acetic acid, oxalic acid, which forms the above-mentioned composite carrier structure of the present application. In preferred embodiments, in step (2), the binding lubricant is nitric acid and / or citric acid.

[0051] According to the present application, in step (2), the amount of the binding lubricant is 1%-4% of the mass of substance a. In some preferred embodiments, in step (2), the amount of the binding lubricant is 2%-3.5% of the mass of substance a.

[0052] According to the present application, a solvent is further added in the forming process of carrier b, which can be selected in the forming solvent. In some preferred embodiments, the solvent is water.

[0053] According to the present application, in the forming process of carrier b, the amount of the solvent is 50%-70% of the mass of substance a. In some preferred embodiments, the amount of the solvent is 50%-65% of the mass of substance a.

[0054] According to the present application, in step (3), the lanthanum salt or cerium salt is a soluble salt. In some preferred embodiments, the lanthanum salt or cerium salt is a nitrate salt.

[0055] According to the present application, in step (3), the cobalt salt is a soluble salt. In some preferred embodiments, the cobalt salt is a nitrate salt.

[0056] According to the present application, in step (3), the nickel salt is at least one of nickel nitrate, nickel acetate, and nickel oxalate. In some preferred embodiments, in step (3), the nickel salt is nickel nitrate.

[0057] According to the present application, in step (3), the mass ratio of the lanthanum salt or cerium salt: cobalt salt: nickel salt is 1:0.5:1-1:1.5:1.5. In some preferred embodiments, in step (3), the mass ratio of the lanthanum salt or cerium salt: cobalt salt: nickel salt is 1:0.67:1-1:1.2:1.2.

[0058] According to the present application, in step (3), the solvent for preparing the impregnation solution c is at least one of water, alcohol, and dilute acid. In some preferred embodiments, in step (3), the solvent for preparing the impregnation solution c is water.

[0059] According to the present application, in step (3), an equal-volume impregnation method is used.

[0060] According to the present application, in step (3), the time for placing the carrier b in the impregnation solution c is 1-3 h. In some preferred embodiments, in step (3), the time for placing the carrier b in the impregnation solution c is 1.5-2 h.

[0061] According to the present application, in step (3), the drying temperature for the second drying is 80-130°C, preferably 95-110°C; and the drying time is 300-500 min, preferably 350-450 min.

[0062] According to the present application, in step (3), the first calcination is performed by raising the temperature of the second dried semi-product to 170-280°C at a rate of 1-5°C / min, holding the temperature for 1-3 h, and then raising the temperature to 350-450°C at a rate of 1-5°C / min, holding the temperature for 1-3 h.

[0063] According to the present application, in step (4), the time for placing the mixture d in the impregnation solution e is 200-400 min. In some preferred embodiments, in step (4), the time for placing the mixture d in the impregnation solution e is preferably 250-300 min.

[0064] According to the present application, in step (4), the drying temperature for the third drying is 70-120°C, preferably 75-95°C; and the drying time is 350-550 min, preferably 400-500 min.

[0065] According to the present application, in step (4), the second calcination is performed by raising the temperature of the third dried semi-product to 160-210°C at a rate of 1-5°C / min, holding the temperature for 1-3 h, and then raising the temperature to 380-580°C at a rate of 1-5°C / min, holding the temperature for 1-3 h.

[0066] According to the present application, in some preferred embodiments, in step (3), the first baking is to heat the second dried semi-product to 180-250℃ at a rate of 1-4℃ / min, constant temperature baking for 1-2h, then heat to 350-450℃ at a rate of 1-4℃ / min, constant temperature baking for 2-3h; in step (4), the second baking is to heat the third dried semi-product to 180-200℃ at a rate of 1-4℃ / min, constant temperature baking for 1-2h, then heat to 400-550℃ at a rate of 1-4℃ / min, constant temperature baking for 2-3h.

[0067] According to the present application, in step (4), the ruthenium salt is a water-soluble salt. In some preferred embodiments, the ruthenium salt is ruthenium chloride.

[0068] According to the present application, in step (4), the equal volume impregnation method is adopted.

[0069] According to the present application, in step (4), the shape of the catalyst can be set as needed. In some preferred embodiments, the shape of the catalyst is a cylindrical barrel with a diameter of 7x7mm, a middle ring diameter of 1mm, and a wall thickness of 3mm.

[0070] The second aspect of the present application provides a hydrocarbon steam reforming catalyst prepared by the above preparation method, which takes ruthenium, nickel, and cobalt as active components, and takes kalsilite- sepiolite as a composite carrier. The active metal components of the catalyst prepared by the present application are distributed in multiple layers along the radial direction of the carrier. The outermost layer of the core is ruthenium, the catalyst additive is lanthanum oxide or cerium oxide, the active metal component in the middle layer of the shell is nickel oxide and cobalt oxide, and the core is nickel oxide, forming a multi-layer structure. The outermost layer of the core provides the initial activity of the catalyst to facilitate the preliminary conversion reaction, and the hydrogen produced gradually diffuses into the interior of the catalyst to reduce the oxidized metal, thereby improving the activity of the catalyst. The modular hydrogen production device conversion catalyst can be gradually reduced by self-produced hydrogen, achieving the purposes of environmental protection and energy saving, and meeting the use requirements of the modular hydrogen production device conversion catalyst.

[0071] The conversion catalyst of the present application contains 7.02-14% (m / m) of active components, the thickness of the outermost layer of the core of the catalyst is 0.5-1mm, the thickness of the middle layer of the shell is 0.5-1mm, and the thickness of the core layer is 1-2mm.

[0072] The active components are distributed in layers of ruthenium, cobalt oxide, and nickel oxide (i.e., the outermost active component of the core is ruthenium, the catalyst promoter is lanthanum oxide or cerium oxide, the active components of the middle shell are nickel oxide and cobalt oxide, and the core is nickel oxide). The ruthenium content accounts for 0.02-0.2% of the catalyst mass, lanthanum oxide or cerium oxide accounts for 0.5-1.5% of the catalyst mass, nickel oxide accounts for 5.5-8.5% of the catalyst mass, and cobalt oxide accounts for 1-3.8% of the catalyst mass. The remaining components of the catalyst are composite supports. The prepared impregnation solution satisfies the relationship C=C1 / C2, A=C×ґ / Ԑ (the value of C ranges from 0.3-5, the value of ґ ranges from 2.2-7, the value of Ԑ ranges from 1.6-2.2, and the value of A ranges from 0.3-20). Under these conditions, the support is impregnated with an impregnation solution of appropriate concentration of active components, which can effectively form a multilayer distribution of active components.

[0073] The catalyst support prepared by this invention has a pore volume controlled at ≥0.35mL / g and a lateral crushing strength at ≥300N / cm. The raw materials are light hydrocarbons such as natural gas, syngas, and refinery gas. The active component nickel and cobalt have a particle size of less than or equal to 12nm.

[0074] The hydrocarbon steam reforming catalyst prepared by this invention is suitable for use in a modular light hydrocarbon hydrogen production unit with a reformer inlet temperature of 450-650℃ and an outlet temperature of 750-880℃, and a carbon space velocity of 10000 h⁻¹. －1 Hydrogen production process conditions: total water-to-carbon ratio 2.0-3.5; pressure 2.0-4.0 MPa. It is worth noting that the application scenarios of this invention are not limited to these.

[0075] The hydrocarbon steam reforming catalyst prepared by this invention can achieve self-reduction activation of the catalyst in modular units without external hydrogen when applied in industrial applications. It is self-reducible, and has high activity and high resistance to carbon deposition, resulting in good economic benefits and broad application prospects.

[0076] Unless otherwise specified, the raw materials used in the examples and comparative examples are all commercially available products.

[0077] Example 1: Preparation of hydrocarbon steam reforming catalyst

[0078] (1) Take 20.9g of potassium feldspar and 62.8g of sepiolite in an aqueous solution containing 16.9g of potassium hydroxide at a concentration of 40wt%, soak at 220℃ for 200min, let it settle, remove impurities, and dry at 90℃ for 420min to obtain substance a;

[0079] (2) Mix substance a with 3g polyethylene glycol, 3g nitric acid and 56g water to form carrier b;

[0080] (3) Dissolve lanthanum nitrate and cobalt nitrate, and add 38.3 g of nickel nitrate and 55 g of water to obtain impregnation liquid c. After placing b in c for 1.5 hours, dry at 95°C for 400 minutes, increase the temperature to 250°C at a rate of 3°C / min, and keep the temperature constant for 2 hours. Then increase the temperature to 450°C at a rate of 3°C / min, and keep the temperature constant for 3 hours to obtain mixture d;

[0081] wherein the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C*ґ / Ԑ, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions; A is the influence factor; ґ is the catalyst tortuosity factor; and Ԑ is the porosity of the carrier particles; wherein the values of C, A, ґ, and Ԑ are shown in Table 1.

[0082] (4) Take 0.97 g of ruthenium chloride and prepare impregnation liquid e by the equal-volume impregnation method. After placing d in e for 300 minutes, dry at 85°C for 500 minutes, increase the temperature to 180°C at a rate of 3°C / min, and keep the temperature constant for 2 hours. Then increase the temperature to 550°C at a rate of 3°C / min, and keep the temperature constant for 2.5 hours to obtain a hydrocarbon steam reforming catalyst.

[0083] Example 2, Preparation of a hydrocarbon steam reforming catalyst

[0084] (1) Take 23.1 g of potassium feldspar and 69.3 g of sepiolite, and immerse them in an aqueous solution containing 18.6 g of potassium hydroxide with a concentration of 35 wt% at 250°C for 300 minutes. After settling, remove the impurities, and dry at 100°C for 360 minutes to obtain substance a;

[0085] (2) Mix substance a with 3 g of polyethylene glycol and 3 g of nitric acid, and add 60 g of water to form a carrier b;

[0086] (3) Dissolve lanthanum nitrate and cobalt nitrate, and add 22.9 g of nickel nitrate and 50 g of water to obtain impregnation liquid c. After placing b in c for 2 hours, dry at 95°C for 450 minutes, increase the temperature to 200°C at a rate of 2°C / min, and keep the temperature constant for 2 hours. Then increase the temperature to 400°C at a rate of 2°C / min, and keep the temperature constant for 3 hours to obtain mixture d;

[0087] wherein the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C*ґ / Ԑ, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions; A is the influence factor; ґ is the catalyst tortuosity factor; and Ԑ is the porosity of the carrier particles; wherein the values of C, A, ґ, and Ԑ are shown in Table 1.

[0088] (4) Take 0.12 g of ruthenium chloride prepared by the equal volume impregnation method to prepare impregnation liquid e, place d in e for 280 min, dry at 95°C for 350 min, heat to 200°C at a rate of 2°C / min, and heat at constant temperature for 1.5 h, then heat to 550°C at a rate of 2°C / min, and heat at constant temperature for 2 h to obtain a hydrocarbon steam reforming catalyst.

[0089] Example 3, Preparation of a Hydrocarbon Steam Reforming Catalyst

[0090] (1) Take 14.7 g of potassium feldspar and 73.4 g of sepiolite in an aqueous solution containing 11.8 g of potassium hydroxide with a concentration of 20 wt%, soak at 250°C for 250 min, settle, remove impurities, and dry at 110°C for 360 min to obtain substance a;

[0091] (2) Mix substance a, 3 g of polyethylene glycol, 3 g of nitric acid, and 64 g of water to form a carrier b;

[0092] (3) Dissolve lanthanum nitrate and cobalt nitrate, and add 30.9 g of nickel nitrate and 52 g of water to obtain impregnation liquid c. Place b in c for 1.5 hours, dry at 110°C for 350 min, heat to 250°C at a rate of 4°C / min, heat at constant temperature for 2 h, then heat to 400°C at a rate of 3°C / min, and heat at constant temperature for 2.5 h to obtain a mixture d;

[0093] Wherein, the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=Cxg / E, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions; A is the influence factor; g is the catalyst tortuosity factor; E is the carrier particle porosity; wherein, the values of C, A, g, and E are shown in Table 1;

[0094] (4) Take 1.2 g of ruthenium chloride and prepare impregnation liquid e by the equal volume impregnation method. Place d in e for 250 min, dry at 75°C for 550 min, heat to 200°C at a rate of 4°C / min, heat at constant temperature for 2 h, then heat to 550°C at a rate of 3°C / min, and heat at constant temperature for 3 h to obtain a hydrocarbon steam reforming catalyst.

[0095] Comparative Example 1, Preparation of a Hydrocarbon Steam Reforming Catalyst

[0096] (1) Take 21.6 g of potassium feldspar and 64.9 g of sepiolite in an aqueous solution containing 17.4 g of potassium hydroxide with a concentration of 40 wt%, soak at 220°C for 200 min, settle, remove impurities, and dry at 90°C for 420 min to obtain substance a;

[0097] (2) Mix substance a, 3 g of polyethylene glycol, 3 g of nitric acid, and 58 g of water to form a carrier b;

[0098] (3) dissolve lanthanum nitrate and cobalt nitrate, and add 39.6 g of nickel nitrate and 57 g of water to obtain impregnation liquid c; after placing b in c for 1.5 hours, dry at 95°C for 400 min, increase the temperature to 250°C at a rate of 3°C / min, and then increase the temperature to 450°C at a rate of 3°C / min, and keep the temperature constant for 3 h to obtain mixture d;

[0099] wherein the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C*ґ / Ԑ, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions; A is an influence factor; ґ is a catalyst tortuosity factor; and Ԑ is the porosity of the carrier particles; wherein the values of C, A, ґ, and Ԑ are shown in Table 1;

[0100] (4) take 1.38 g of ruthenium chloride to prepare impregnation liquid e by the equal-volume impregnation method; after placing d in e for 250 min, dry at 85°C for 500 min, increase the temperature to 180°C at a rate of 3°C / min, and then increase the temperature to 550°C at a rate of 3°C / min, and keep the temperature constant for 2.5 h to obtain a hydrocarbon steam reforming catalyst.

[0101] Preparation of a hydrocarbon steam reforming catalyst

[0102] (1) take 83.8 g of sepiolite and immerse in an aqueous solution containing 16.9 g of potassium hydroxide with a concentration of 40 wt% at 220°C for 200 min, and then settle and remove impurities, and dry at 90°C for 420 min to obtain substance a;

[0103] (2) mix substance a, 3 g of polyethylene glycol, 3 g of nitric acid, and 56 g of water to form a carrier b;

[0104] (3) dissolve lanthanum nitrate and cobalt nitrate, and add 38.3 g of nickel nitrate and 55 g of water to obtain impregnation liquid c; after placing b in c for 1.5 hours, dry at 95°C for 400 min, increase the temperature to 250°C at a rate of 3°C / min, and then increase the temperature to 450°C at a rate of 3°C / min, and keep the temperature constant for 3 h to obtain mixture d;

[0105] wherein the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C*ґ / Ԑ, C1 is the concentration of cobalt ions; C2 is the concentration of lanthanum ions; A is an influence factor; ґ is a catalyst tortuosity factor; and Ԑ is the porosity of the carrier particles; wherein the values of C, A, ґ, and Ԑ are shown in Table 1;

[0106] (4) Take 0.97g of ruthenium chloride and prepare impregnation solution e by equal volume impregnation method. Place d in e for 300min, dry at 85℃ for 500min, heat to 180℃ at a rate of 3℃ / min, calcine at constant temperature for 2h, and then heat to 550℃ at a rate of 3℃ / min and calcine at constant temperature for 2.5h to obtain hydrocarbon steam reforming catalyst.

[0107] Comparative Example 3: Preparation of Hydrocarbon Steam Reforming Catalysts

[0108] (1) Take 14.5g of potassium feldspar and 72.4g of sepiolite in an aqueous solution containing 11.7g of potassium hydroxide at a concentration of 20wt%, soak at 220℃ for 200min, let it settle, remove impurities, and dry at 90℃ for 420min to obtain substance a;

[0109] (2) Mix substance a with 3g polyethylene glycol, 3g nitric acid and 60g water to form carrier b;

[0110] (3) Dissolve lanthanum nitrate and cobalt nitrate, and add 37.3g of nickel nitrate and 57g of water to obtain impregnation solution c. Place b in c for 1.5 hours, dry at 95℃ for 400min, raise the temperature to 250℃ at a rate of 3℃ / min, calcine at a constant temperature for 2h, and then raise the temperature to 450℃ at a rate of 3℃ / min and calcine at a constant temperature for 3h to obtain mixture d;

[0111] The concentration of the impregnation solution c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=C*ґ / Ԑ, where C1 is the cobalt ion concentration; C2 is the lanthanum ion concentration; A is the influencing factor; ґ is the catalyst tortuosity factor; and Ԑ is the carrier particle porosity. The values ​​of C, A, ґ, and Ԑ are shown in Table 1.

[0112] Take 1.38g of ruthenium chloride and prepare impregnation solution e using the equal volume impregnation method. Place d in e for 250min, dry at 85℃ for 500min, heat to 180℃ at a rate of 3℃ / min, calcine at a constant temperature for 2h, and then heat to 550℃ at a rate of 3℃ / min and calcine at a constant temperature for 2.5h to obtain hydrocarbon steam reforming catalyst.

[0113] Table 1 Composition of hydrocarbon steam reforming catalysts

[0114] .

[0115] Test Example 1: Performance Testing of Hydrocarbon Steam Reforming Catalysts

[0116] use Figure 1 The small-scale pressurized evaluation device and evaluation conditions shown were used to test the hydrocarbon steam reforming catalysts prepared in the above examples and comparative examples.

[0117] The specific evaluation conditions include: the hydrocarbon raw material is mixed with water vapor in a vaporization mixer through a metering pump and enters a reactor, and the converted gas is vented after being analyzed by chromatography. The reactor is a tubular reactor with an inner diameter of φ19 mm, and the outer part is heated in four sections, and the temperature can be adjusted in sections. The first section of heating corresponds to an empty tube, and the main function is to heat the raw material. The second, third, and fourth sections of heating are for the hydrocarbon steam conversion catalyst.

[0118] During the evaluation of the hydrocarbon steam conversion catalyst, the heating section outside the reactor is used as insulation to minimize heat exchange with the outside environment. The reactor is equipped with a φ6 mm thermocouple tube, and four thermocouples are used, corresponding to the inlet, 1 / 3, 1 / 2, and outlet of the catalyst bed.

[0119] Catalyst: broken into 10-20 mesh, loaded with 45 mL of bed height 270 mm.

[0120] Using n-hexane as the raw material, the pressure is 3.0 MPa, the carbon space velocity is 10000 h -1 -1, H2O / C (mol / mol) is 2.0; the bed temperature is: the inlet temperature is 480℃, the outlet temperature is 700℃, and the operation time is 100h.

[0121] The results are shown in Table 2 below.

[0122] Table 2 Performance test results of hydrocarbon steam conversion catalyst

[0123] .

[0124] As can be seen from Table 2, the hydrocarbon steam conversion catalyst of the embodiment of the present application is slowly activated, and the use of self-produced hydrogen gradually reduces the active components of the catalyst, which is a self-reduction process. The catalyst activity gradually increases, and the high activity of the catalyst fully meets the use requirements, with low carbon content and high carbon deposition resistance.

[0125] In Comparative Example 1, the active component ruthenium is higher than the range value, the active component cobalt is lower than the range value, and the active component lanthanum is higher than the range value. The active component particle size of the obtained catalyst D is large, the hydrogen production is less, and the carbon content of the sample is high. In Comparative Example 2, there is only one carrier sepiolite, and the values of ð and Ԑ are higher than the range values. The active component particle size of the obtained catalyst E is significantly larger, and the carbon content of the sample is significantly higher. In Comparative Example 3, the active component ruthenium is higher than the range value, the active component cobalt is lower than the range value, and the active component lanthanum is higher than the range value. The value of C is lower than the range value, and the value of ð is higher than the range value. Compared with Comparative Example 1, the active component particle size is larger, and the carbon content of the sample is higher.

[0126] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and do not constitute a limitation on the content of the present application. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A process for the preparation of a hydrocarbon steam reforming catalyst, characterized in that, The application relates to a catalyst and a preparation method thereof. The catalyst comprises the following steps: (1) a certain amount of potassium feldspar and sepiolite are soaked in potassium hydroxide solution at a certain temperature for a certain time, impurities are removed, and a material a is obtained through first drying; (2) the material a and a carrier additive are mixed to form a carrier b, and the carrier b is a composite carrier; (3) a lanthanum salt or cerium salt and a cobalt salt are dissolved, a certain amount of a nickel salt is added, an impregnation liquid c is prepared, the carrier b is placed in the impregnation liquid c for a certain time, and a mixture d is obtained through second drying and first calcination; wherein the concentration of the impregnation liquid c and the porosity of the carrier b satisfy the following relationship: C=C1 / C2, A=Cxg / E, C1 is the concentration of cobalt ions, C2 is the concentration of lanthanum ions or cerium ions, A is an influence factor, g is a catalyst tortuosity factor, E is the porosity of carrier particles, the value range of C is 0.3-5, the value range of g is 2.2-7, the value range of E is 1.6-2.2, and the value range of A is 0.3-20; (4) a ruthenium salt is taken to prepare an impregnation liquid e, the mixture d is placed in the impregnation liquid e for a certain time, and a catalyst is obtained through third drying and second calcination. In the prepared catalyst, the content of ruthenium is 0.02-0.2% of the catalyst mass, the content of lanthanum oxide or cerium oxide is 0.5-1.5% of the catalyst mass, the content of nickel oxide is 5.5-8.5% of the catalyst mass, the content of cobalt oxide is 1-3.8% of the catalyst mass, and the remaining components of the catalyst are the composite carrier. In step (1), the mass ratio of the potassium feldspar to the sepiolite is 1:4-1:

8. In step (1), the soaking time is 180-360 min. In step (1), the soaking temperature is 200-250 DEG C. In step (2), the carrier additive is at least one of polyethylene glycol, starch and sucrose.

2. The production method according to claim 1, characterized by, In step (3), the nickel salt is at least one of nickel nitrate, nickel acetate and nickel oxalate, and the lanthanum salt or cerium salt is a soluble salt.

3. The preparation method according to claim 1, characterized in that, In step (3), the mass ratio of the lanthanum salt or cerium salt to the cobalt salt to the nickel salt is 1:0.67:1-1:1.2:1.

2.

4. The production method according to claim 1, characterized by, In step (3), the first calcination is that the second-dried semi-product is heated to 180-250 DEG C at a speed of 1-4 DEG C / min, is kept at the temperature for 1-2 h, is then heated to 350-450 DEG C at a speed of 1-4 DEG C / min, and is kept at the temperature for 2-3 h; in step (4), the second calcination is that the third-dried semi-product is heated to 180-200 DEG C at a speed of 1-4 DEG C / min, is kept at the temperature for 1-2 h, is then heated to 400-550 DEG C at a speed of 1-4 DEG C / min, and is kept at the temperature for 2-3 h.

5. The method of claim 1, wherein, In step (4), the ruthenium salt is a water-soluble salt.

6. The method of claim 1, wherein, In the prepared catalyst, the content of ruthenium is 0.02-0.2% of the catalyst mass, the content of lanthanum oxide or cerium oxide is 0.5-1.5% of the catalyst mass, the content of nickel oxide is 5.5-8.5% of the catalyst mass, the content of cobalt oxide is 1-3.8% of the catalyst mass, and the remaining components of the catalyst are the composite carrier.

7. The preparation method according to claim 1, characterized in that, ​ 8. The method of claim 1, wherein, ​ 9. The method of claim 1, wherein, ​ 10. The hydrocarbon steam reforming catalyst prepared according to the preparation method of any one of claims 1-9, wherein the active components of the catalyst are distributed in multiple layers along the radial direction of the carrier, the outermost layer of the core is ruthenium, the catalyst promoter is lanthanum oxide or cerium oxide, the active component of the middle layer of the shell is nickel oxide or cobalt oxide, and the core is nickel oxide; wherein, ​

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