CN115041173B - Ferronickel bimetallic flower-like cluster catalyst and preparation and application methods thereof - Google Patents

Ferronickel bimetallic flower-like cluster catalyst and preparation and application methods thereof Download PDF

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CN115041173B
CN115041173B CN202210802748.8A CN202210802748A CN115041173B CN 115041173 B CN115041173 B CN 115041173B CN 202210802748 A CN202210802748 A CN 202210802748A CN 115041173 B CN115041173 B CN 115041173B
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gas
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CN115041173A (en
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杨双霞
赵文祥
华栋梁
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Energy Research Institute of Shandong Academy of Sciences
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    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/78—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with alkali- or alkaline earth metals
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    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/323—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
    • C01B3/326—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents characterised by the catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
    • C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1041—Composition of the catalyst
    • C01B2203/1047—Group VIII metal catalysts
    • C01B2203/1052—Nickel or cobalt catalysts
    • C01B2203/1058—Nickel catalysts
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Abstract

The catalyst is formed by orderly self-assembling nano sheets, the cluster size is 257-1220nm, the diameter of the nano sheets is about 143-341nm, and the thickness is 14.3-29nm. NiFe bimetal is used as a main catalytic active component, wherein the mass percentage of Ni is 32.4% -37.1%, and the mass percentage of Fe is 19.9% -34.6%. The preparation method comprises the following steps: preparing flower-like cluster hydrotalcite precursors with laminates containing Ni-Fe-Al or Ni-Fe-Al-Mg by adopting a one-step urea hydrolysis method; calcining the hydrotalcite precursor for 2-4 hours in an inert atmosphere, and naturally cooling to room temperature to obtain the ferronickel bimetallic flower-like cluster catalyst. The application method of the catalyst in preparing hydrogen-rich gas by biomass pyrolysis and reforming comprises the following steps: and respectively filling biomass materials and a mixture of a catalyst and quartz sand in the two-stage fixed bed reaction device, so that volatile matters generated by pyrolysis of the biomass materials are cracked and reformed on the surface of the ferronickel bimetallic flower-shaped cluster catalyst dispersed in the quartz sand, and hydrogen-rich gas is obtained.

Description

Ferronickel bimetallic flower-like cluster catalyst and preparation and application methods thereof
Technical Field
The invention belongs to the field of energy chemical industry, and particularly relates to a flower-shaped cluster Ni-Fe bimetallic catalyst and a preparation method thereof and an application method thereof in preparing hydrogen-rich gas by biomass catalytic reforming.
Background
The hydrogen energy is a well-known and ideal green energy, and the development and utilization of the hydrogen energy not only can get rid of long-term dependence on traditional fossil energy, but also can solve the problems of energy shortage and environmental pollution, and has important significance for promoting the carbon peak and the carbon neutralization process. Biomass (especially agriculture and forestry waste) has huge yield, can regenerate and can produce CO 2 Zero emission is considered as a strategic choice for future energy systems, and hydrogen production by using biomass is attracting more and more attention. The thermochemical utilization technology has the advantages of high conversion speed, high efficiency and the like, can controllably convert biomass with a complex structure into high-quality liquid fuel, synthesis gas, carbon materials and chemicals, and is one of utilization technologies with great development prospects. Especially, the addition of the catalyst can further improve the cracking conversion efficiency of biomass, reduce the thermal conversion reaction temperature and improve the selectivity of target products, and becomes a hot spot for research and application in the fields of international energy sources, materials, chemical industry, environment and the like.
The biomass catalytic conversion with the hydrogen-rich gas as the target refers to the process of degrading and fragmenting macromolecular polymers such as cellulose, hemicellulose, lignin and the like in raw materials to generate intermediate macromolecular products, and finally generating micromolecular gas with a stable structure through repeated cracking, mutual reaction and photopolymerization. Because the H/C ratio in the biomass raw material is low, H in the obtained gas product 2 The content is generally low. In addition, the reaction time and the reaction intensity are limited in the actual conversion process, and the macromolecular intermediate product cannot be completely cracked and converted, and finally exists in the product in the form of tar. Lower H 2 The further conversion and utilization of the gaseous product is limited by both the content and the presence of tar. The nickel-based catalyst has strong capability of breaking C-C bond and C-H bond and simultaneously has high water vapor and CO resistance 2 The reforming reaction has higher catalytic activity and can deeply convert tar generated in the pyrolysis process into H in situ 2 And CO. While the iron-based active component has a higher content ofHigh water gas shift reactivity, can improve H in gas 2 Is selected from the group consisting of (1). Meanwhile, certain electronic effect exists between the double active components, so that the thermal stability and the reactivity of the active center can be synergistically improved. Therefore, the design optimization of the bimetal ferronickel composite catalyst is a key for realizing the efficient and directional conversion of biomass to hydrogen-rich gas by cooperatively strengthening each reaction process.
However, bimetallic nickel-iron composite catalysts often face carbon deposition challenges. The tar macromolecules are subjected to ring opening, side chain cutting, deoxidization and molecular reconstruction to form hydrocarbon micromolecules in the actual conversion process, dehydration or dehydrogenation reaction is carried out on the metal active sites, the generated carbon intermediates are polymerized to form carbon deposition organic macromolecules, and if the macromolecules cannot be timely diffused, the carbon deposition organic macromolecules cover the metal active sites and block the pore channel structure, so that the problems of reduced catalytic activity and even inactivation are caused.
Disclosure of Invention
The invention overcomes the defects in the prior art, provides a flower-shaped cluster ferronickel bimetallic composite catalyst with orderly self-assembled nanosheets, and simultaneously provides a preparation method and an application method thereof in preparing hydrogen-rich gas by biomass catalytic reforming.
The invention solves the technical problems by adopting the following technical scheme: the ferronickel bimetallic flower-shaped cluster catalyst is formed by orderly self-assembling nano sheets, wherein the cluster size is 257-1220nm, the diameter of the nano sheets is about 143-341nm, and the thickness of the nano sheets is 14.3-29nm. NiFe bimetal is used as a main catalytic active component, wherein the mass percentage of Ni is 32.4% -37.1%, and the mass percentage of Fe is 19.9% -34.6%.
The application also provides the preparation of the ferronickel bimetallic flower-like cluster catalyst, which comprises the following steps:
(1) Preparation of flower-like cluster layered metal hydroxide precursor: ni (NO) 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O and Al (NO) 3 ) 3 ∙9H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ ) Ratio of =5/4, orNi (NO) 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O、Al(NO 3 ) 3 ∙9H 2 O and Mg (NO) 3 ) 2 ∙6H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ +Mg 2+ ) A ratio of =5/4 was dissolved in deionized water to prepare a mixed salt solution, where n represents the amount of substance, and n (Ni 2+ ）/n（Fe 3+ ) 1 to 1.5; in addition according to n (urea)/n (M) Total (S) ) Weighing urea with a certain mass according to a proportion of (2-5), adding deionized water to dissolve the urea to prepare a solution, wherein n (M Total (S) ) Is Ni 2+ +Fe 3+ +Al 3+ The total mass of three metal ions or Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ The total mass of the four metal ions; pouring the mixed salt solution and the urea solution into a reaction container, wherein the reaction container is filled with the mixed salt solution and the urea solution in a range of 90-120 DEG C o C. Continuously stirring and crystallizing for 24-48 h at a lower rotating speed, centrifuging and washing the obtained slurry until the supernatant is neutral, drying at 80 ℃ for 12h, and grinding to obtain a Ni-Fe-Al LDHs precursor or a Ni-Fe-Al-Mg LDHs precursor;
(2) Calcining: weighing a certain amount of Ni-Fe-AlLDHs or Ni-Fe-Al-Mg LDHs precursor obtained in the step (1), placing the Ni-Fe-AlLDHs or Ni-Fe-Al-Mg LDHs precursor in a tubular atmosphere furnace, calcining the Ni-Fe-Al-Mg LDHs precursor for 2-4 hours at the temperature of 500-800 ℃ in an inert atmosphere, and naturally cooling the Ni-Fe-Al precursor to room temperature to obtain the nano-sheet ordered self-assembled Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst or the nano-sheet ordered self-assembled Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst.
The invention is also characterized in that the urea is used in the preparation step (1) in an amount which is 5 times the total amount of metal ions.
The application also provides an application method of the ferronickel bimetallic flower-like cluster catalyst in preparing hydrogen-rich gas by biomass catalytic reforming, which comprises the following steps:
the method comprises the steps of filling biomass materials in a sample basket of a primary reactor of a two-stage fixed bed reaction device, and keeping the basket away from a heating area of the reactor before heating; filling the prepared ferronickel bimetallic flower-like cluster catalyst into a secondary reactor, and mixing with quartz sandThe material is used as a catalyst bed, wherein the mass ratio of quartz sand to the catalyst is 1-3, and CaO is added below the catalyst bed to be used as an adsorbent; introducing N 2 Discharging air in a reaction device, heating two reactors to a set temperature, quickly feeding a hanging basket into a constant temperature area of a primary reactor for quick pyrolysis, introducing deionized water above the hanging basket in the primary reactor by adopting a constant flow pump, pyrolyzing biomass materials at 600-900 ℃, and evaporating generated volatile matters and the deionized water to generate water vapor at a flow rate of 25-50 mL/min N 2 Carrying the pyrolysis gas to carry out pyrolysis and reforming on the surface of a ferronickel bimetallic flower-shaped cluster catalyst in a catalyst bed at 500-800 ℃, and adsorbing CO in situ by CaO 2 And condensing in a U-shaped tube immersed in ice water bath, and drying silica gel to obtain gas and liquid products.
The invention is also characterized in that the deionized water adding speed in the step (b) is 0.1-0.6 ml/min. And (b) adding CaO in an amount which is 1-4 times of the mass of the catalyst.
The invention has the beneficial effects that: 1. the invention provides a flower-shaped cluster ferronickel bimetallic catalyst with orderly self-assembled nanosheets, wherein the mass percentage of Ni in the catalyst is 32.4% -37.1%, the mass percentage of Fe is 19.9% -34.6%, and the mass percentage of Ni+Fe double active components is up to 52.3% -71.7%. Compared with the prior art, the preparation method has the advantages that the flower-shaped cluster ferronickel bimetallic catalyst is prepared by adopting the urea hydrolysis method in one step, a substrate or a carrier is not needed in the preparation process, any organic reagent, a structure inducer or a surfactant is not needed to be added, the preparation condition is mild, the operation is easy, the content of active components in the obtained catalyst is high, the magnetism is easy to separate, and the industrial mass production, the recycling and the reutilization of the catalyst are facilitated.
2. The ferronickel bimetallic flower-shaped cluster catalyst prepared by the method can fully expose the catalytic active sites on the surfaces of the nano sheets to ensure that the nano sheets have excellent cracking performance on tar, and the filling mode of mixing the catalyst with quartz sand is adopted in the biomass catalytic pyrolysis process, so that the dispersibility of the catalyst can be remarkably improved at a lower carrier flow rate, and the biomass pyrolysis volatile matters and the catalyst are promoted to be carried outThe contact is sufficient. Under the condition of no water reforming, the Ni-Fe-Al, ni-Fe-Al-Mg flower-like cluster catalyst has a catalytic temperature of 700 DEG C o And C, the tar can be completely cracked and converted. Compared with the prior art, the tar cracking rate is obviously improved under the same reaction condition.
3. The ferronickel bimetallic flower-like cluster catalyst prepared by the invention has excellent tar reforming and water gas shift reaction activities in the biomass conversion process. Reforming with addition of water and CaO as CO 2 Under the condition of the adsorbent, the Ni-Fe-Al-Mg flower-shaped cluster catalyst can completely crack and reform tar into micromolecular gas, the maximum gas yield reaches 1509ml/g, and simultaneously, the H is improved 2 Yield was found to be 39.3mmol/g. Compared with the prior art, the gas production rate and H under the same experimental condition 2 The yield is obviously improved.
4. The ordered mesoporous/macroporous pore canal among the nano sheets in the ferronickel bimetallic flower-shaped cluster catalyst prepared by the invention effectively promotes the diffusion migration of the carbon deposition precursor, inhibits the carbon deposition on the surface of the active site, improves the stability and the service life of the catalyst, ensures that the gas yield of the catalyst is up to 812ml/g after the catalyst is repeatedly used for 8 times without regeneration, and has H 2 Yield was 15.02mmol/g, H 2 the/CO ratio was still maintained at 1.77.
Drawings
FIG. 1 is a scanning electron micrograph of the Ni-Fe-Al-Mg flower-like cluster catalyst obtained in example 1. FIG. 2 is a scanning electron micrograph of the Ni-Fe-Al-Mg catalyst obtained in example 3. FIG. 3 is a scanning electron micrograph of the Ni-Fe-Al flower-like cluster catalyst obtained in example 4.
Detailed Description
Example 1: a Ni-Fe-Al-Mg flower-like cluster catalyst prepared by urea hydrolysis method is prepared by the following steps:
1. according to Ni 2+ ：Fe 3+ ：Al 3+ ：Mg 2+ 21.81g of Ni (NO) were weighed in a mass ratio of 2.5:2.5:1:3 3 ) 2 ∙6H 2 O、30.3g Fe(NO 3 ) 3 ∙9H 2 O、11.25g Al(NO 3 ) 3 ∙9H 2 O and 23.08g of Mg (NO) 3 ) 2 ∙6H 2 Adding deionized water into O to prepare 300ml mixed salt solution, and adding n (urea)/n (M) Total (S) ) Ratio of=5 weigh 81g urea in deionized water to make 300mL urea solution, where n (M Total (S) ) Is Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ Total mass of four metal ions. Pouring the mixed salt solution and the urea solution into a four-neck flask with the volume of 1L, raising the temperature of a water bath kettle to 95 ℃ under continuous stirring, crystallizing for 24 hours, centrifuging and washing the obtained slurry with deionized water until the supernatant is neutral, drying for 12 hours at 80 ℃, and grinding to obtain the Ni-Fe-Al-Mg LDHs flower-shaped cluster precursor.
2. Weighing 10g of Ni-Fe-Al-MgLDHs precursor, uniformly spreading on a magnetic boat, placing in a tubular atmosphere furnace, heating to 600 ℃ at 10 ℃/min under nitrogen atmosphere, calcining for 2h, and naturally cooling to room temperature to obtain the Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst.
The Ni-Fe-Al-Mg catalyst prepared by the method is amplified by 5 ten thousand times by adopting a Scanning Electron Microscope (SEM), and the nano-sheets in the catalyst are orderly self-assembled into flower-shaped cluster morphology, the cluster size is 480nm, the diameter of the nano-sheets is about 247nm, and the thickness is 14.3nm. The catalyst is made of NiFe 2 O 4 Three phases of NiO and Mg (Al) O. The mass percent of Ni in the catalyst is 37.1%, the mass percent of Fe is 34.6%, and the mass percent of Ni+Fe is 71.7%.
The application method of the prepared Ni-Fe-Al-Mg flower-shaped cluster catalyst in preparing hydrogen-rich gas by biomass catalytic pyrolysis comprises the following steps: 4g of wood chips are filled in a sample basket of a primary reactor of the two-stage fixed bed reaction device, and the basket is far away from a heating area of the reactor before heating. 2g of the prepared Ni-Fe-Al-Mg catalyst is filled in a secondary reactor and mixed with 4g of quartz sand, and carrier gas N is introduced 2 Discharging air in the reaction device, simultaneously heating the two reactors to 700 ℃ at a heating rate of 20 ℃/min, quickly feeding a hanging basket filled with biomass into a constant temperature area of the first-stage reactor for quick pyrolysis, and generating pyrolysis volatile matters in N with a flow rate of 25mL/min 2 Enters a catalyst bed layer under the carrying, and is evenly dispersed in the quartz sandThe Al-Mg catalyst surface is cracked and converted, the obtained cracked gas is condensed in a U-shaped tube immersed in ice water bath, and then the gas and liquid products are respectively obtained through silica gel drying. The gas product was analyzed by Agilent 7890A gas chromatograph, equipped with Thermal Conductivity Detector (TCD) and Flame Ionization Detector (FID), with high purity N 2 Is carrier gas, CO and H 2 、CH 4 、O 2 And N 2 Separating with molecular sieve column, and separating CO 2 And C 2 -C 3 (including ethylene, ethane, propane) was separated using a poraflot Q column. Gas yield and gas composition Using N 2 And (5) calculating by an internal standard method.
The tar yield obtained by pure pyrolysis of wood chips is 0.36 g/g biomass without adding a catalyst, the gas yield is 0.48g/g biomass, the gas yield is 340mL/g, and typical components of the gas are (volume percent): h 2 ：12.29%、CO：43.47%、CO 2 ：16.54%、CH 4 ：18.46%，C 2 -C 3 (ethylene, ethane, propane): 9.25%, where H 2 Yield was 2.19 mmol/g, H 2 the/CO ratio was 0.28.
Tar and gas generated by pyrolysis and gasification of biomass with the components are subjected to on-line pyrolysis conversion. It is found that under the action of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst, tar is completely cracked, the conversion rate is as high as 100%, the gas yield is 0.88g/g biomass, and the total gas yield is 1119mL/g. The gas composition is (volume percent): h 2 ：45.34%、CO：40.79%、CO 2 ：9.70%、CH 4 ：3.96%、C 2 -C 3 (ethylene, ethane, propane): 0.21%, where H 2 Yield was 22.66 mmol/g, H 2 the/CO ratio was 1.11. Compared with pure pyrolysis, the Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst completely cracks pyrolysis tar into H 2 、CO、CO 2 、CH 4 And small molecular gas is equalized, so that the gas yield is increased by more than 2 times. For CH 4 、C 2 -C 3 Also exhibits excellent C-H bond breaking ability in the gas, forming more H 2 Molecules, H 2 The volume content is increased by 2.7 times, the yield is increased by 9.3 times, and the corresponding H 2 the/CO ratio was increased from 0.28 to 1.11.
Example 2:
this example is identical to example 1, and is not repeated, except that n (urea)/n (M Total (S) ) =2, i.e. urea and Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ The ratio of the total mass of the four metal ions is 2, and 32.5g of urea is weighed during the experiment. The Ni-Fe-Al-Mg catalyst prepared by the method is amplified by 2 ten thousand times by adopting SEM, and the ordered self-assembly of the nano-sheets in the catalyst is still in the shape of flower-shaped clusters, the cluster size is 1.22 mu m, the diameter of the nano-sheets is about 341nm, and the thickness is 29nm. The catalyst is made of NiFe 2 O 4 Three phases of NiO and Mg (Al) O. The mass percent of Ni in the catalyst is 34.44%, the mass percent of Fe is 20.4%, and the mass percent of Ni+Fe is 54.84%. Compared with the example 1, the reduction of the urea addition amount increases the sizes of the Ni-Fe-Al-Mg bimetallic flower-like clusters and the nano-sheets, reduces the content of Ni and Fe active components in the catalyst, mainly reduces the content of generated-OH due to the reduction of the urea content, and reduces the content of Mg 2+ And Al 3+ Is more easily combined with-OH to enter the LDHs structure.
Catalyst evaluation was performed under the same experimental conditions as in example 1, and it was found that the conversion rate of tar was still 100% for the ni—fe—al—mg bimetallic catalyst prepared under this condition, the total gas yield was 1058 mL/g, and the gas components were (volume percent): h 2 ：44.94%、CO：40.99%、CO 2 ：9.74%、CH 4 ：4.33%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield was 21.24 mmol/g, H 2 the/CO ratio was 1.10. From the catalytic effect, the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst still shows higher catalytic reaction activity and can completely crack pyrolysis tar into H 2 、CO、CO 2 、CH 4 And small molecular gas is equalized to ensure gas yield and H 2 Yield and H 2 the/CO ratio is significantly increased over pure pyrolysis. Gas yield and H compared to example 1 2 The slight decrease in yield can be attributed mainly to the increased size and reduced Ni, fe active component content.
Example 3:
this example is identical to example 1, and is not repeated, except that n (urea)/n (M Total (S) ) =1.5, i.e. urea and Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ The ratio of the total mass of the four metal ions was 1.5, and 24.38g of urea was weighed during the experiment. The Ni-Fe-Al-Mg catalyst prepared by the method is amplified by 2 ten thousand times by adopting SEM, and is found to be in an incomplete flower-shaped cluster shape and has a large number of scattered nano-sheet structures, wherein the cluster size is about 2.17 mu m, the diameter of the nano-sheet is about 458nm, and the thickness is about 32.65nm. The catalyst is made of NiFe 2 O 4 Three phases of NiO and Mg (Al) O. The mass percentage of Ni in the catalyst is 22.51%, the mass percentage of Fe is 14.32%, and the mass percentage of Ni+Fe is 36.83%. Compared with the example 1, the continuous reduction of the urea addition amount leads to the destruction of the structural part of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster, the obvious increase of the sizes of the cluster and the nano-sheet, and the obvious reduction of the content of Ni and Fe active components in the catalyst.
Catalyst evaluation was conducted under the same experimental conditions as in example 1, and it was found that the Ni-Fe-Al-Mg bimetallic catalyst prepared under this condition had a tar conversion of 42% and a total gas yield of 683 mL/g, and the gas components were (volume percent): h 2 ：33.82%、CO：25.01%、CO 2 ：27.16%、CH 4 ：14.00%、C 2 -C 3 (ethylene, ethane, propane): 4.91%, where H 2 Yield was 10.31 mmol/g, H 2 the/CO ratio was 1.35. From the catalytic effect, compared with example 1, the gas yield is reduced by about 38.9%, and the gas yield is reduced due to the damage of the flower-like structure and the lower Ni and Fe contents, so that the surfaces of the nano-sheets cannot provide more reactive sites for tar cracking, and the catalytic activity is greatly reduced.
Example 4:
the embodiment is the same as that of embodiment 1, and is not described in detail, except that Mg is not added in the preparation process of the catalyst according to Ni 2+ ：Fe 3+ ：Al 3+ Amount of substanceThe ratio is 3:2:4, 26.17g Ni (NO) 3 ) 2 ∙6H 2 O、24.24g Fe(NO 3 ) 3 ∙9H 2 O and 45.02g Al (NO) 3 ) 3 ∙9H 2 The O is added with deionized water to prepare 300ml mixed salt solution. SEM observation shows that the nano-sheets in the prepared Ni-Fe-Al bimetallic catalyst are orderly self-assembled into flower-shaped cluster morphology, the cluster size is 280 nm, the diameter of the nano-sheets is about 143nm, and the thickness is about 21.4 nm. The catalyst consists of NiO and Fe 0.99 Ni 0.6 Al 1.1 O 4 The composition comprises 33.05% by mass of Ni, 19.92% by mass of Fe and 52.97% by mass of Ni+Fe.
The performance evaluation of hydrogen-rich gas produced by catalytic pyrolysis of biomass was carried out under the same experimental conditions as in example 1. The research shows that under the action of the Ni-Fe-Al bimetallic catalyst, the tar conversion rate is 100%, the total gas yield is 915mL/g, and the gas components are (volume percent): h 2 ：35.56%、CO：42.66%、CO 2 ：15.45%、CH 4 ：6.33%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield was 16.97 mmol/g, H 2 the/CO ratio was 0.83. In comparison with example 1, the Ni-Fe-Al bimetallic catalyst was still able to crack the pyrolysis tar completely to H when an Al-based single support was used 2 、CO、CO 2 、CH 4 And small molecular gas. Fe (Fe) 0.99 Ni 0.6 Al 1.1 O 4 The formation of the CO-solution improves the reactivity and promotes CO 2 、CH 4 、C 2 -C 3 Reforming of gases by cracking into more H 2 And CO.
Example 5:
this example is the same as example 4, except that Ni is used in the catalyst preparation process 2 + ：Fe 3+ ：Al 3+ The mass ratio of the substances is 2.5:2.5:4, 21.81g Ni (NO) 3 ) 2 ∙6H 2 O、30.3g Fe(NO 3 ) 3 ∙9H 2 O and 45.02g Al (NO) 3 ) 3 ∙9H 2 O is added toThe ionized water is prepared into 300ml mixed salt solution. SEM observation shows that the nano-sheets in the prepared Ni-Fe-Al bimetallic catalyst are orderly self-assembled into flower-shaped cluster morphology, the cluster size is 257nm, the diameter of the nano-sheets is about 178nm, and the thickness is 15.2nm. The catalyst consists of NiO and Fe 0.99 Ni 0.6 Al 1.1 O 4 The composition comprises 32.39% of Ni, 30.6% of Fe and 62.99% of Ni+Fe.
The performance evaluation of hydrogen-rich gas produced by catalytic pyrolysis of biomass was carried out under the same experimental conditions as in example 4. It was found that when n (Ni 2+ ）/n（Fe 3+ ) When the catalyst is 1, the tar conversion rate under the action of the Ni-Fe-Al bimetallic catalyst is 100%, the total gas yield is 1018 mL/g, and the gas components are (volume percent): h 2 ：42.84%、CO：40.78%、CO 2 ：11.71%、CH 4 ：4.67%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield 19.45 mmol/g, H 2 The ratio of/CO was 1.05. When n (Ni 2+ ）/n（Fe 3+ ) When the catalyst is 1, the structural morphology of the Ni-Fe-Al bimetallic catalyst is not changed obviously, and the mass of Ni+Fe active components is increased, so that the cracking reforming efficiency of tar is still kept high, and the gas yield and H are generated 2 The yield is increased. It can be seen that Fe 0.99 Ni 0.6 Al 1.1 O 4 The formation of the CO-solution improves the reactivity and promotes CO 2 、CH 4 、C 2 -C 3 Reforming of gas cracking to H 2 And CO.
Example 6:
this example is the same as example 4, and is not repeated, except that the catalyst active component is made of single metal Fe or Ni, i.e., according to Fe 3+ ：Al 3+ Or Ni 2+ ：Al 3+ The Fe-Al or Ni-Al single metal catalyst is prepared according to the mol ratio of 5:4. The Fe-Al catalyst prepared by the method is in a particle-stacked block shape, the nano particle size is about 100 nm, and the phase comprises Fe 2 O 3 And amorphous Al 2 O 3 Wherein Fe isThe weight percentage content is 58.7%. The orderly self-assembled flower-shaped cluster shape and cluster size of the prepared Ni-Al catalyst is 1.85 mu m, the diameter of the nano-sheet is about 923nm, and the thickness of the nano-sheet is about 35.9nm. The catalyst consists of NiO and amorphous Al 2 O 3 The composition comprises 50.5 mass percent of Ni.
Catalyst evaluation was performed under the same experimental conditions as in example 4, and it was found that the tar conversion was 42% with the Fe-Al single metal catalyst, the total gas yield was 619 mL/g, and the gas composition was (volume percent): h 2 ：30.89%、CO：29.90%、CO 2 ：22.74%、CH 4 ：12.65%、C 2 -C 3 (ethylene, ethane, propane): 3.82%, where H 2 Yield was 8.53 mmol/g, H 2 The ratio of/CO was 1.03. The tar conversion rate under the action of the Ni-Al monometallic catalyst is 64%, the total gas yield is 944 mL/g, and the gas components are (volume percent): h 2 ：48.53%、CO：34.20%、CO 2 ：13.87%、CH 4 ：3.30%、C 2 -C 3 (ethylene, ethane, propane): 0.1%, where H 2 Yield was 20.45mmol/g, H 2 the/CO ratio was 1.42. Compared with example 4, under the same reaction conditions, the monometallic catalyst can not completely crack and convert tar, and the gas yield is reduced. For Fe-Al single metal catalyst, H 2 The contents of components such as CO and the like are obviously reduced, and the CO 2 、CH 4 、C 2 -C 3 The gas content is increased, mainly due to the weak C-C breaking capacity of Fe, and tar macromolecules can not be effectively cracked and reformed into H 2 And CO. Whereas Ni-Al single metal catalyst shows higher water gas shift reaction activity, H in gas component 2 、CO 2 The content is increased, the CO content is reduced, but compared with Fe-Ni-Al bimetallic, a certain amount of tar exists in the product, the gas yield is reduced, which indicates that the synergistic effect exists between Ni-Fe bimetallic, and tar macromolecules can be effectively cracked.
Example 7:
this example is the same as example 1, and is not repeated, except that only 2g of the prepared Ni-Fe-Al-Mg catalyst is charged in the secondary reactor, and quartz is not addedAnd (5) sand. It was found that under the action of the Ni-Fe-Al-Mg bimetallic catalyst, the tar yield was 0.11 g/g biomass, the conversion rate was 69%, the gas yield was 0.73 g/g biomass, the total gas yield was 978 mL/g, and the gas components were (volume percent): h 2 ：40.31%、CO：33.56%、CO 2 ：16.94%、CH 4 ：7.55%、C 2 -C 3 (ethylene, ethane, propane): 1.64%, where H 2 Yield 17.6mmol/g, H 2 the/CO ratio was 1.2. Compared with example 1, when quartz sand is not added in the experimental process, the tar rapidly passes through the catalyst bed layer under the carrying of carrier gas, so that part of the tar can not be completely cracked and converted by contacting with the catalyst, the tar conversion rate is reduced, and the gas production rate is reduced.
Example 8:
this example is the same as example 1, and is not repeated, except that the amount of quartz sand added in the secondary reactor is increased to 6g. The research shows that under the action of the Ni-Fe-Al-Mg bimetallic catalyst, tar is completely cracked, the conversion rate is as high as 100%, the gas yield is 0.86g/g biomass, and the total gas yield is 1021 mL/g. The gas composition is (volume percent): h 2 ：38.64%、CO：36.78%、CO 2 ：16.17%、CH 4 ：8.42%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield 17.61 mmol/g, H 2 The ratio of/CO was 1.05. Compared with the embodiment 1, the added quartz sand is increased to ensure that the catalyst maintains higher dispersivity, can promote the complete conversion of tar and strengthen the water gas shift reaction, while the highly dispersed catalyst simultaneously prolongs the diffusion path of reactants such as tar, water and the like, so that the gas yield and H are ensured 2 The yield is slightly decreased.
Example 9:
this example is the same as example 8, and is not repeated, except that the addition amount of quartz sand in the secondary reactor is continuously increased to 8g. It was found that under the action of the Ni-Fe-Al-Mg bimetallic catalyst, the tar yield was 0.09 g/g biomass, the conversion was 74%, the gas yield was 0.74 g/g biomass, the total gas yield was 930mL/g, and the gas components were (volume percent):H 2 ：43.18%、CO：36.93%、CO 2 ：12.18%、CH 4 ：7.16%、C 2 -C 3 (ethylene, ethane, propane): 0.54%, where H 2 Yield 17.92mmol/g, H 2 the/CO ratio was 1.17. When the addition of silica sand was continued during the experiment, the gas yield was reduced compared to example 8, mainly due to excessive catalyst dispersion when the silica sand was excessive, and tar and water vapor could not be completely converted while passing through the catalyst bed.
Example 10:
this embodiment is the same as embodiment 1, and is not described in detail, except that the carrier gas N 2 The flow rate was 50mL/min. It was found that under the action of the Ni-Fe-Al-Mg bimetallic catalyst, the tar yield was 0.03 g/g biomass, the conversion rate was 92%, the gas yield was 0.81 g/g biomass, the total gas yield was 948 mL/g, and the gas components were (volume percent): h 2 ：40.79%、CO：35.41%、CO 2 ：16.04%、CH 4 ：7.57%、C 2 -C 3 (ethylene, ethane, propane): 0.19%, where H 2 Yield 17.26mmol/g, H 2 the/CO ratio was 1.15. The catalyst reactivity was comparable to that of example 7 when the carrier gas flow rate was increased and quartz sand was not added. Compared to example 1, tar conversion and gas yield decreased, mainly because increasing carrier gas flow rate caused the tar to pass through the catalyst bed quickly, and even with quartz sand as a buffer, tar contact time with the catalyst active site was limited and still not completely cracked, resulting in decreased gas yield.
Example 11:
this embodiment is the same as embodiment 10 and will not be described again, except that the carrier gas N 2 The flow rate continues to increase to 100mL/min. It was found that under the action of the Ni-Fe-Al-Mg bimetallic catalyst, the tar yield was 0.12 g/g biomass, the conversion rate was 67%, the gas yield was 0.72 g/g biomass, the total gas yield was 819 mL/g, and the gas components were (volume percent): h 2 ：41.14%、CO：24.54%、CO 2 ：22.27%、CH 4 ：9.16%、C 2 -C 3 (ethylene, ethane, propane): 0.82%, thereinH 2 Yield was 15.03mmol/g, H 2 the/CO ratio was 1.68. Compared to example 10, the tar cracking rate was reduced, mainly due to the increased carrier gas flow rate, which caused the tar to pass through the catalyst bed quickly, even with quartz sand as a buffer, the tar had limited contact time with the catalyst active site, resulting in a reduction in gas yield.
Example 12:
the embodiment is the same as embodiment 1, and is not repeated, except that when the reactor reaches the set temperature, deionized water of 0.1ml/min is added into the reaction system through a constant flow pump to enable the pyrolysis volatile components of the biomass to be cracked and simultaneously carry out reforming reaction. It is found that under the steam reforming condition generated by deionized water, the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst can still fully crack and convert pyrolysis tar into micromolecular gas, the tar conversion rate is 100%, the gas yield reaches 0.93g/g biomass, the total gas yield is increased to 1249mL/g, and the increased gas yield mainly comes from the decomposition of additional deionized water and the conversion of part of coke, so that more gas products are formed. The gas composition is (volume percent): h 2 ：47.33%、CO：26.46%、CO 2 ：19.07%、CH 4 ：6.01%、C 2 -C 3 (ethylene, ethane, propane): 1.13%, where H 2 Yield 26.38 mmol/g, H 2 the/CO ratio was 1.79. Compared with the embodiment 1, the addition of deionized water aggravates the tar reforming reaction and the water gas shift reaction, so that the CO content in the product is reduced, H 2 And CO 2 The gas content is increased, H 2 the/CO ratio was increased from 1.11 to 1.79.
Example 13:
this example is the same as example 12, except that 2g CaO as CO is further added to the lower layer of the catalyst and silica sand mixture 2 Adsorbent, by CO 2 In situ absorption changes the balance of the water gas shift chemical reaction to produce more H 2 . Research has found that CO-reforming in catalysis 2 Under the absorption action, the conversion rate of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst to tar is still 100%, and the gas yield is 0.88g/g biomass, so that the total gas production is realizedThe amount was increased to 1317 mL/g. The gas component being (volume percent) H 2 ：56.64%、CO：28.36%、CO 2 ：11.45%、CH 4 ：3.56%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield 33.29 mmol/g, H 2 the/CO ratio was 2.00. Compared with example 12, CO after CaO addition 2 The content is significantly reduced and more water is promoted to participate in the reaction by changing the balance of the water gas shift reaction, so that more gas products are generated. H 2 The yield was increased to 33.29 mmol/g, at which time H 2 The ratio of/CO is also increased from 1.79 to 2.00, and the gas yield is slightly reduced mainly due to part of the CO in the gas 2 Absorbed.
Example 14:
this example is the same as example 13, and will not be described again, except that the CaO addition amount is increased to 8g. Research has found that CO-reforming in catalysis 2 Under the absorption action, the conversion rate of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst to tar is still 100%, and the total gas yield is 1184 mL/g. The gas component being (volume percent) H 2 ：57.53%、CO：29.06%、CO 2 ：8.37%、CH 4 ：5.04%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield was 30.41mmol/g, H 2 the/CO ratio was 1.98. The increase in CaO addition amount further reduces CO in the gas as compared with example 13 2 And promote CH 4 The total gas yield is reduced due to gas generation. This is mainly due to the reaction of excess CaO with water vapor generated by the evaporation of deionized water to form Ca (OH) 2 So that the steam amount involved in the reforming reaction and the water gas shift reaction is reduced.
Example 15:
this example is the same as example 14, and will not be described again, except that the CaO addition amount is increased to 10g. Research has found that CO-reforming in catalysis 2 Under the absorption action, the conversion rate of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst to tar is still 100%, and the total gas yield is 1172 mL/g. The gas component being (volume percent) H 2 ：55.37%、CO：26.76%、CO 2 ：12.84%、CH 4 ：4.26%、C 2 -C 3 (ethylene, ethane, propane): 0.78%, where H 2 Yield 28.99mmol/g, H 2 the/CO ratio was 2.06. Further increase in CaO addition amount compared to example 14 did not decrease CO in the gas 2 Mainly due to the excess CaO in adsorbing CO 2 In the process, a large amount of CaCO is formed on the surface 3 Shell layer, limit CO 2 The diffusion and adsorption of the gas, while excess CaO consumes part of the water to weaken the water gas shift reaction and reduce the total gas yield slightly.
Example 16:
this example is the same as example 13, and is not repeated, except that the deionized water addition amount is increased to 0.6ml/min. Research has found that CO-reforming in catalysis 2 Under the absorption action, the conversion rate of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst to tar is still 100%, the gas yield is 1.08g/g biomass, and the total gas yield is 1509 mL/g. The gas component being (volume percent) H 2 ：58.33%、CO：17.59%、CO 2 ：22.21%、CH 4 ：1.87%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield was 39.3mmol/g, H 2 the/CO ratio was 3.32. The increase in the amount of deionized water added further aggravates the water gas shift reaction of CO and CH compared to example 13 4 So that the gas yield is further increased. With CO consumption and more H 2 Is generated such that H in the synthesis gas 2 the/CO ratio was increased to 3.32. In addition, more water vapor forms small molecule gases as a raw material.
Example 17:
this example is the same as example 16, and is not repeated, except that the deionized water addition amount is further increased to 0.8 ml/min. The research shows that under the action of excessive deionized water, the conversion rate of the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst to tar is still 100%, and the total gas yield is slightly reduced to 1468 mL/g. The gas component being (volume percent) H 2 ：58.24%、CO：16.93%、CO 2 ：23.33%、CH 4 ：1.5%、C 2 -C 3 (ethylene, ethane, propane): 0, wherein H 2 Yield 38.2 mmol/g, H 2 the/CO ratio was 3.44. Further increases in the amount of deionized water added compared to example 16 had little effect on gas yield and composition, indicating that the reaction had equilibrated at this time. The slight decrease in total gas production is mainly due to the fact that the addition of excess deionized water consumes more energy to gasify it, which results in a slight decrease in the temperature in the reactor, which in turn affects gas production.
Example 18:
this example is the same as example 16, and is not repeated, except that the catalyst after the reaction of example 16 is used 8 times without regeneration cycle. The research shows that the Ni-Fe-Al-Mg bimetallic flower-shaped cluster catalyst still shows better reaction activity in the 8 th catalytic experiment, the tar conversion rate is 67%, the total gas yield is 812mL/g, and the gas components are (volume percent): h 2 ：41.45%、CO：23.39%、CO 2 ：23.23%、CH 4 ：9.08%、C 2 -C 3 (ethylene, ethane, propane): 2.85%, where H 2 Yield was 15.02mmol/g, H 2 the/CO ratio was 1.77. Compared with the pure pyrolysis in the example 1, the Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst still shows excellent C-H bond breaking capacity on tar after 8 times of recycling, and the gas yield is 2.4 times of that of the pure pyrolysis. While still maintaining higher reforming and water gas shift reaction performance, promoting CH 4 、C 2 -C 3 Cracking and reforming of gases to more H 2 Molecules, H 2 The content is increased by 2.4 times, corresponding to H 2 the/CO ratio was increased by a factor of 5.3. The Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst has excellent stabilizing energy.
Example 19:
the Chinese patent application CN106955709A (preparation method of three-dimensional flower-shaped supported bimetallic copper-nickel nano catalyst) provides a preparation method of a three-dimensional flower-shaped supported bimetallic copper-nickel nano catalyst, which comprises the following specific preparation scheme: firstly, taking a mixed solution of isopropyl alcohol and water as a solvent, and preparing amorphous Al through hydrothermal synthesis and roasting 2 O 3 Microsphere carrierAmorphous Al is then added 2 O 3 Microspheres, metal solution (nickel acetate and copper acetate), alkali solution (ammonium nitrate and hexamethylenetetramine) are subjected to surface in-situ growth under hydrothermal conditions to obtain layered LDHs precursor containing copper, nickel and aluminum, and finally the layered LDHs precursor is subjected to air roasting-nitrogen-hydrogen mixed gas reduction to obtain the highly-dispersed flower-shaped bimetallic CuNi nano catalyst. With reference to the preparation scheme and the specific experimental conditions of the invention example 1, in the example, copper acetate is changed into ferric nitrate in the preparation process, and the flower-shaped supported bimetallic NiFe nano catalyst is prepared. SEM observation shows that the obtained amorphous Al 2 O 3 The diameter of the microsphere is 1.2 mu m, and the nano-sheets are formed to be perpendicular to Al in a staggered way through in-situ growth 2 O 3 Flower-like Al of microsphere 2 O 3 Loading NiFeAl-LDHs precursor, al 2 O 3 The size of the microspheres was reduced to 709nm due to consumption. The flower-shaped supported bimetallic NiFe nano catalyst obtained after roasting and reduction has the size of 2.75 mu m, the diameter of the nano sheet is about 419nm, the thickness is 50nm, the mass percent of Ni in the catalyst is 19.8%, the mass percent of Fe is 9.4%, and the mass percent of Ni+Fe is 29.2%. In this example, a flower-like structure and a size are remarkably different from those of the Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst obtained in example 1, and the inside of the flower-like catalyst is composed of Al 2 O 3 The microspheres are used as a nanosheet growth metal source and a carrier, the nanosheet size is obviously increased, and the clusters in the embodiment 1 are completely formed by self-assembly of the nanosheets, so that a more extended lamellar structure is formed, and the content of effective active components in the catalyst is improved.
Catalyst evaluation was performed under the same experimental conditions as in example 1, and it was found that the flower-shaped supported bimetallic NiFe nanocatalyst prepared under this condition had a tar conversion of 55.6%, a gas yield of 0.70g/g biomass, a total gas yield of 841mL/g, and a gas composition of (volume percent): h 2 ：45.34%、CO：26.96%、CO 2 ：18.32%、CH 4 ：6.76%、C 2 -C 3 (ethylene, ethane, propane): 2.62%, where H 2 Yield 17.03 mmol/g, H 2 the/CO ratio was 1.68. Compared with example 1, the flower-shaped supported bimetallic obtained in this exampleTar conversion rate, gas yield and H under the action of NiFe nano catalyst 2 The productivity is greatly reduced, CH in gas 4 、C 2 -C 3 The increase of the content shows that the reduction of the content of Ni and Fe active components and the larger size of the catalyst obtained by adopting the preparation scheme of the embodiment weaken the breaking activity of C-C bonds in tar macromolecules.

Claims (6)

1. The ferronickel bimetallic flower-shaped cluster catalyst for preparing hydrogen-rich gas by biomass catalytic reforming is characterized in that the catalyst is formed into flower-shaped cluster morphology by orderly self-assembling nano sheets, wherein the cluster size is 257-1220nm, the diameter of the nano sheets is 143-341nm, and the thickness is 14.3-29nm; niFe bimetal is used as a main catalytic active component, wherein the mass percentage of Ni is 32.4% -37.1%, and the mass percentage of Fe is 19.9% -34.6%; the preparation method of the ferronickel bimetallic flower-like cluster catalyst comprises the following steps:
(1) Preparation of flower-like cluster layered metal hydroxide precursor: ni (NO) 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O and Al (NO) 3 ) 3 ∙9H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ ) A ratio of =5/4, or Ni (NO 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O、Al(NO 3 ) 3 ∙9H 2 O and Mg (NO) 3 ) 2 ∙6H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ +Mg 2+ ) In a ratio of =5/4, in deionized water to prepare a mixed salt solution, wherein n represents the amount of the substance, and n (Ni 2+ ）/n（Fe 3+ ) 1 to 1.5; in addition according to n (urea)/n (M) Total (S) ) Weighing urea with a certain mass according to a proportion of (2-5), adding deionized water to dissolve the urea to prepare a solution, wherein n (M Total (S) ) Is Ni 2+ +Fe 3+ +Al 3+ The total mass of three metal ions or Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ The total mass of the four metal ions; pouring the mixed salt solution and urea solution into a reaction vessel,continuously stirring and crystallizing for 24-48 hours at 90-120 ℃ and a lower rotating speed, centrifuging and washing the obtained slurry until the supernatant is neutral, drying for 12 hours at 80 ℃, and grinding to obtain a Ni-Fe-AlLDHs precursor or a Ni-Fe-Al-MgLDHs precursor;
(2) Calcining: weighing a certain amount of Ni-Fe-AlLDHs or Ni-Fe-Al-MgLDHs precursor obtained in the step (1), placing in a tubular atmosphere furnace, calcining for 2-4 hours at 500-800 ℃ in an inert atmosphere, and naturally cooling to room temperature to obtain the nano-sheet ordered self-assembled Ni-Fe-Al bimetallic flower-like cluster catalyst or the nano-sheet ordered self-assembled Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst.
2. The method for preparing the ferronickel bimetallic flower-like cluster catalyst according to claim 1, which is characterized by comprising the following steps:
(1) Preparation of flower-like cluster layered metal hydroxide precursor: ni (NO) 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O and Al (NO) 3 ) 3 ∙9H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ ) A ratio of =5/4, or Ni (NO 3 ) 2 ∙6H 2 O、Fe(NO 3 ) 3 ∙9H 2 O、Al(NO 3 ) 3 ∙9H 2 O and Mg (NO) 3 ) 2 ∙6H 2 O is according to n (Ni 2+ +Fe 3+ ）/n（Al 3+ +Mg 2+ ) In a ratio of =5/4, in deionized water to prepare a mixed salt solution, wherein n represents the amount of the substance, and n (Ni 2+ ）/n（Fe 3+ ) 1 to 1.5; in addition according to n (urea)/n (M) Total (S) ) Weighing urea with a certain mass according to a proportion of (2-5), adding deionized water to dissolve the urea to prepare a solution, wherein n (M Total (S) ) Is Ni 2+ +Fe 3+ +Al 3+ The total mass of three metal ions or Ni 2+ +Fe 3+ +Al 3+ +Mg 2+ The total mass of the four metal ions; pouring the mixed salt solution and the urea solution into a reaction container, continuously stirring and crystallizing for 24-48 hours at the temperature of 90-120 ℃ and at a lower rotating speed, centrifuging and washing the obtained slurryThe supernatant is neutral, and is dried for 12 hours at 80 ℃ and then ground to obtain a Ni-Fe-AlLDHs precursor or a Ni-Fe-Al-MgLDHs precursor;
(2) Calcining: weighing a certain amount of Ni-Fe-AlLDHs or Ni-Fe-Al-MgLDHs precursor obtained in the step (1), placing in a tubular atmosphere furnace, calcining for 2-4 hours at 500-800 ℃ in an inert atmosphere, and naturally cooling to room temperature to obtain the nano-sheet ordered self-assembled Ni-Fe-Al bimetallic flower-like cluster catalyst or the nano-sheet ordered self-assembled Ni-Fe-Al-Mg bimetallic flower-like cluster catalyst.
3. The method for preparing a ferronickel bimetallic flower-like cluster catalyst according to claim 2, wherein the urea is used in an amount 5 times the total amount of metal ions in the preparation step (1).
4. The method for using the ferronickel bimetallic flower-like cluster catalyst in preparing hydrogen-rich gas by biomass catalytic reforming according to claim 1, which is characterized by comprising the following steps:
the method comprises the steps of filling biomass materials in a sample basket of a primary reactor of a two-stage fixed bed reaction device, and keeping the basket away from a heating area of the reactor before heating; filling the prepared mixture of the ferronickel bimetallic flower-shaped cluster catalyst and quartz sand serving as a catalyst bed in a secondary reactor, wherein the mass ratio of the quartz sand to the catalyst is 1-3, and simultaneously adding CaO serving as an adsorbent below the catalyst bed; introducing N 2 Discharging air in a reaction device, heating two reactors to a set temperature, quickly feeding a hanging basket into a constant temperature area of a primary reactor for quick pyrolysis, introducing deionized water above the hanging basket in the primary reactor by adopting a constant flow pump, pyrolyzing biomass materials at 600-900 ℃, and evaporating generated volatile matters and the deionized water to generate water vapor at a flow rate of 25-50 mL/min N 2 Carrying the pyrolysis gas to carry out pyrolysis and reforming on the surface of a ferronickel bimetallic flower-shaped cluster catalyst in a catalyst bed at 500-800 ℃, and adsorbing CO in situ by CaO 2 And condensing in a U-shaped tube immersed in ice water bath, and drying silica gel to obtain gas and liquid products.
5. The method for using the ferronickel bimetallic flower-like cluster catalyst in preparing hydrogen-rich gas by biomass catalytic reforming according to claim 4, wherein the deionized water adding speed is 0.1-0.6 mL/min.
6. The application method of the ferronickel bimetallic flower-like cluster catalyst in preparing hydrogen-rich gas by biomass catalytic reforming according to claim 4, wherein the CaO addition amount is 1-4 times of the mass of the catalyst.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101181686A (en) * 2007-12-06 2008-05-21 上海大学 Hydrotalcite type hydrocracking catalyst and method for preparing same
CN101829539A (en) * 2010-05-21 2010-09-15 大连理工大学 Method for preparing NiAl composite oxide desulfurizing agent with flower-shaped appearance
CN106955709A (en) * 2017-01-13 2017-07-18 北京化工大学 A kind of preparation method of three-dimensional flower-shaped load type double-metal cupro-nickel nanocatalyst
CN107537504A (en) * 2016-06-29 2018-01-05 华东师范大学 A kind of self-supporting Raney nickel and its preparation and application
CN110227468A (en) * 2019-07-15 2019-09-13 山东省科学院能源研究所 Nickel calcium based composite catalysis agent preparation and application during catalytic pyrolysis of biomass
CN112924514A (en) * 2021-01-15 2021-06-08 黑龙江大学 Nickel-iron-aluminum LDHs modified biomass charcoal material and application thereof in heavy metal ion detection
CN113426450A (en) * 2021-06-18 2021-09-24 嘉兴学院 Biomass tar steam reforming monolithic catalyst and preparation method thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200055030A1 (en) * 2016-11-17 2020-02-20 The Regents Of The University Of California HIGH TAR CONVERSION PERFORMANCE OF A Nl-FE-MGO CATALYST

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101181686A (en) * 2007-12-06 2008-05-21 上海大学 Hydrotalcite type hydrocracking catalyst and method for preparing same
CN101829539A (en) * 2010-05-21 2010-09-15 大连理工大学 Method for preparing NiAl composite oxide desulfurizing agent with flower-shaped appearance
CN107537504A (en) * 2016-06-29 2018-01-05 华东师范大学 A kind of self-supporting Raney nickel and its preparation and application
CN106955709A (en) * 2017-01-13 2017-07-18 北京化工大学 A kind of preparation method of three-dimensional flower-shaped load type double-metal cupro-nickel nanocatalyst
CN110227468A (en) * 2019-07-15 2019-09-13 山东省科学院能源研究所 Nickel calcium based composite catalysis agent preparation and application during catalytic pyrolysis of biomass
CN112924514A (en) * 2021-01-15 2021-06-08 黑龙江大学 Nickel-iron-aluminum LDHs modified biomass charcoal material and application thereof in heavy metal ion detection
CN113426450A (en) * 2021-06-18 2021-09-24 嘉兴学院 Biomass tar steam reforming monolithic catalyst and preparation method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"CaO 基催化剂在生物质热解中原位脱碳作用研究";谢新苹等;《山东科学》;第32卷(第5期);88-93 *
"Elucidating the origin mechanism of a morphology‑dependent layered double hydroxide catalyst toward organic contaminant oxidation via persulfate activation";Rongyao Wang et al.;《Environmental Science and Pollution Research》;第29卷;79126–79139 *
"Pyrolysis of sawdust with various Fe-based catalysts: Influence of support characteristics on hydrogen-rich gas production";Shuangxia Yang et al.;《Journal of Analytical and Applied Pyrolysis》;第137卷;结论 *

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