A biomass conversion catalyst, its preparation method and use

Abstract

The application discloses a biomass conversion catalyst and a preparation method and application thereof, the catalyst comprising a carrier and an active metal component, the active metal component being distributed on the surface and in the pores of the carrier; the carrier is a core-shell structure comprising a core and a shell layer, the core being ZSM-5 molecular sieve containing micropores and mesopores, and the shell layer being mesoporous MCM-41 molecular sieve. The application further provides a preparation method and application of the biomass conversion catalyst. By adjusting the pore structure of the carrier and introducing the metal active phase, a high-activity composite structure catalyst is formed, which integrates catalytic cracking, reforming and carbon deposition inhibition and the like in one, realizes efficient and accurate cracking of macromolecular compounds in raw materials in a catalytic pyrolysis reaction, effectively inhibits carbon deposition, reduces the occurrence of side reactions, and obtains high-quality bio-oil products.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomass energy, and relates to a biomass conversion catalytic material and a preparation method and use thereof. BACKGROUND

[0002] Biomass energy is the only renewable energy that can be directly converted into carbonaceous liquid fuel, and it is of great significance to convert it into liquid fuel that can replace fossil fuels through thermochemical means. Biomass catalytic pyrolysis technology has high conversion efficiency, and the main products are liquid bio-oil, H2, small molecule hydrocarbon gas, and part of solid coke and carbon deposition by-products. The use of fast pyrolysis can effectively improve the yield of liquid product bio-oil, and the introduction of catalysts in catalytic pyrolysis reaction can improve the selectivity of aromatic hydrocarbons. Catalytic pyrolysis reaction is mainly divided into in-situ catalytic pyrolysis (in-situ CFP) of biomass raw materials and catalyst pre-mixing and ex-situ catalytic pyrolysis (ex-situ CFP) of separation of the two. The former has higher raw material conversion rate and bio-oil yield due to direct contact of raw materials and catalysts, and the latter can reduce the yield of carbon deposition by-products and protect the catalyst due to the non-direct contact of raw materials and catalysts.

[0003] One of the cores of biomass catalytic pyrolysis for bio-oil technology is the catalyst. At present, the commonly used catalysts in the field mainly include alkali metals and alkaline earth metals, metal oxides, and zeolite molecular sieves. Alkali metals and alkaline earth metals can reduce the oxygen content of liquid products, but due to their strong alkalinity, they can easily cause excessive decomposition of bio-oil, thereby reducing the yield of liquid products. Metal oxide catalysts can reduce the selectivity of some oxygen-containing compounds and improve the stability of bio-oil, but the yield of liquid products is still not high. Molecular sieve catalysts can promote the decomposition and conversion of macromolecular substances, thereby obtaining high-value aromatic hydrocarbons and improving the quality of bio-oil. This type of catalyst has better cracking and deoxygenation ability, and is the focus of biomass catalytic pyrolysis research.

[0004] ZSM-5 molecular sieve has excellent pore structure and acid site advantage, and is paid more and more attention by researchers. However, as a typical microporous molecular sieve catalyst, it has a certain diffusion limitation in the catalytic pyrolysis of biomass. The macromolecular reactants of biomass are difficult to diffuse into the micropore and carry out the catalytic conversion reaction on the active site, resulting in low conversion rate of biomass raw materials and low selectivity of target product monocyclic aromatic hydrocarbon (literature source: AJJ, AGAT, BAJF, et al. Investigation into the shape selectivity of zeolite catalysts for biomass conversion [J]. Journal of Catalysis, 2011, 279 (2): 257-268.).

[0005] Patent CN105032475A discloses a modified ZSM-5 molecular sieve catalyst for biomass pyrolysis to light aromatic hydrocarbon and application. The catalyst comprises the following components by weight: iron oxide: 5-20 parts, cobalt oxide: 5-20 parts, molybdenum oxide: 5-15 parts, gallium oxide: 5-15 parts, ZSM-5 molecular sieve: 30-80 parts. It also needs to go through the following steps to obtain: (1) carrier pretreatment; (2) introduction of main active components; (3) introduction of auxiliary active components; (4) molding of the catalyst. By modifying the ZSM-5 molecular sieve catalyst with metal and applying the modified catalyst to the catalytic pyrolysis of biomass, a light aromatic hydrocarbon yield higher than 70% is obtained, and the catalyst has high stability.

[0006] In combination with the above content, it can be known that ZSM-5 molecular sieve has been successfully used as a catalyst or a catalyst carrier in the process of catalytic pyrolysis of biomass, but there are still certain limitations in the use process. On the one hand, ZSM-5 molecular sieve has a certain diffusion limitation to the macromolecules of biomass, which will further lead to the reduction of the conversion rate of raw materials. On the other hand, the reaction products in the process of biomass pyrolysis are easy to cause the generation of carbon deposition, and the carbon deposition will block the pore channels of the molecular sieve and even poison the active sites, thereby leading to the deactivation of the catalyst and affecting the service life and performance of the catalyst. Therefore, it is still necessary to further improve the ZSM-5 molecular sieve catalyst to solve the problems existing in the prior art and improve the quality of liquid products. SUMMARY

[0007] In view of the problems existing in the prior art, the main purpose of the present application is to provide a biomass conversion catalyst and a preparation method and application thereof. By adjusting the pore structure of the carrier and introducing the metal active phase, a high-activity composite structure catalyst is formed, which integrates catalytic cracking, reforming and carbon deposition inhibition in one, realizes efficient and accurate cracking of macromolecular compounds in the raw materials in the catalytic pyrolysis reaction, effectively inhibits carbon deposition, reduces the occurrence of side reactions, and obtains high-quality bio-oil products.

[0008] In the research process, it is found that the biggest influence of the carbon deposition generated in the reaction on the existing biomass conversion catalyst is that the effective pore of the catalyst is blocked by the carbon deposition, thereby reducing the reaction activity of the catalyst and leading to the reduction of product yield and performance. Since the micro-pore contains more cracking active sites and is the core position of the biomass catalytic pyrolysis reaction, the micro-pore is more easily deactivated and damaged, so protecting the micro-pore becomes a core problem in the modification and preparation of the catalyst. After research, an original "carbon deposition growth space transfer" concept is proposed, which aims to adjust the carbon deposition generation position to the space with the smallest influence on the activity of the catalyst through the regulation of the catalyst, and solves the problem of objective carbon deposition generation. The catalyst prepared by the method can transfer the carbon deposition generation site in the catalytic reaction and inhibit the occurrence of the carbon deposition generation reaction. In the catalyst preparation method of the application, the acid site distribution and acid amount of the catalyst are regulated through desiliconization by alkali treatment, mesoporous shell coating and metal active phase introduction, which can effectively improve the selectivity to the monocyclic aromatic hydrocarbons in the product and inhibit the generation of polycyclic aromatic compounds, so that high-quality bio-oil products are obtained.

[0009] The first aspect of the application provides a biomass conversion catalyst, which comprises a carrier and an active metal component, and the active metal component is distributed on the surface and in the pores of the carrier; the carrier is a core-shell structure comprising a core and a shell layer, the core is ZSM-5 molecular sieve containing two-level pores of micro-pores and mesopores, and the shell layer is mesoporous MCM-41 molecular sieve; the active metal component comprises a first active metal component and a second active metal component, wherein the first active metal is at least one of the group VIII elements, specifically one or more of Ni, Co and Fe, preferably Ni, and the second active metal is an alkaline earth metal, specifically one or more of Mg and Ca, preferably Mg; and the active metal component exists in the form of metal oxide.

[0010] Further, in the above biomass conversion catalyst, as a specific embodiment, the content of the carrier is 70wt%-80wt% based on the weight of the catalyst, the content of the first active metal is 10wt%-20wt% based on the oxide, and the content of the second active metal component is 5wt%-15wt% based on the oxide.

[0011] Further, in the above biomass conversion catalyst, as a specific embodiment, the first active metal component is mainly distributed in the pores of the carrier; and the second active metal component is mainly distributed in the pores of the shell layer mesoporous MCM-41 molecular sieve.

[0012] Further, in the biomass conversion catalyst, as a specific embodiment, the catalyst has a core-shell structure, and the thickness of the mesoporous shell layer is 10-30 nm, and the mesoporous layer is uniformly coated, as shown in the TEM image.

[0013] Further, in the biomass conversion catalyst, the average pore diameter of the catalyst is 2.5-9.5 nm, and preferably 3.5-6.5 nm.

[0014] Further, in the biomass conversion catalyst, as a specific embodiment, the total amount of acid sites of the catalyst is 850-1200 μmol / g, and preferably 950-1050 μmol / g, and the ratio of B acid to L acid (B / L) is 0.70-3.50, and preferably 1.20-2.90.

[0015] Further, in the biomass conversion catalyst, as a specific embodiment, the specific surface area of the catalyst is 450-800 m 2 / g, and preferably 500-650 m 2 / g.

[0016] Further, in the biomass conversion catalyst, the pore volume of the catalyst is 0.40-0.80 cm 3 / g, and preferably 0.55-0.75 cm 3 / g.

[0017] The second aspect of the present application provides a preparation method of a biomass conversion catalyst, comprising the following steps:

[0018] (1) under contact conditions, ZSM-5 molecular sieve is contacted with a treating agent for treatment, and the treated material is quenched, and then separated, washed, dried and calcined to obtain material A;

[0019] (2) under mixing conditions, the material A obtained in step (1), an additive and a solvent are mixed uniformly, and then separated, washed and dried to obtain material B;

[0020] (3) the material B obtained in step (2), a long-chain quaternary ammonium salt solution and a silicon-containing compound are mixed uniformly for reaction, and then separated, washed, dried and calcined to obtain material C;

[0021] (4) an active metal component is introduced into the material C obtained in step (3) to obtain a biomass conversion catalyst.

[0022] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the treating agent in step (1) is a quaternary ammonium base, specifically one or more of tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), and tetrabutylammonium hydroxide (TBPOH), preferably at least one of tetraethylammonium hydroxide and tetrapropylammonium hydroxide. Further, the treating agent is used in the form of an aqueous solution, and the concentration of the aqueous solution of the treating agent is 0.1-2.0 mol / L.

[0023] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the treating temperature in step (1) is 60-80°C, the mass ratio of the ZSM-5 molecular sieve to the treating agent is 1:10-1:50, and the treating time is generally 30-60 min; specifically, the step can be performed under the conditions of water bath heating and stirring.

[0024] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the quenching temperature in step (1) is 0-10°C, and specifically, the material after the treatment can be placed at 0-10°C for a period of time, such as 0.5-1.0 h.

[0025] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the separation in step (1) is solid-liquid separation, and any one of the existing means for achieving solid-liquid separation in the art can be used, such as any one of filtration, centrifugal separation, and the like, and preferably vacuum filtration is used.

[0026] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the washing in step (1) is water washing until the filtrate is neutral, and generally, the washing needs to be performed for multiple times, specifically 1-20 times; and preferably, deionized water is used for the washing.

[0027] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the drying in step (1) is performed at 90-110°C for 6-12 h.

[0028] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the calcination conditions in step (1) are as follows: the calcination temperature is 550-650°C, the calcination time is 4-6 h, and the calcination is performed in an oxygen-containing atmosphere, such as in an air atmosphere.

[0029] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the additive in step (2) is one or more of polydimethyl diallyl ammonium chloride (PDDA) and polyvinylpyrrolidone (PVP), and preferably polydimethyl diallyl ammonium chloride.

[0030] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the solvent in step (2) can be an organic solvent and an inorganic solvent, and preferably an organic solvent; the organic solvent can be an alcohol solution, preferably a small-molecule alcohol solution, specifically an alcohol solution with a carbon atom number of 1-4, specifically at least one of methanol, ethanol and propanol, preferably ethanol, and the concentration of the alcohol is 5wt%-25wt%. The inorganic solvent can be one or more of inorganic salt solutions such as sodium chloride solution and calcium chloride solution, and the mass concentration of the inorganic solvent is generally 10wt%-30wt%.

[0031] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the ratio of the material A, the additive and the solvent in step (2) is 1g:(10-20)mL:(10-25)mL, and the concentration of the additive is 2-3g / L.

[0032] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the separation in step (2) is solid-liquid separation, and any one of the existing solid-liquid separation means in the art can be used, such as any one of filtration and centrifugal separation, and preferably vacuum filtration.

[0033] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the washing in step (2) is washing with water until the filtrate is neutral, and generally needs to be washed for 1-20 times; and preferably deionized water is used for washing.

[0034] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the drying in step (2) is carried out at 90-110°C for 4-8h.

[0035] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the long-chain quaternary ammonium salt in step (3) can be one or more of dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), cetyltrimethylammonium bromide (CTAB) and octadecyltrimethylammonium bromide (STAB); and preferably cetyltrimethylammonium bromide. The quaternary ammonium salt solution is obtained by mixing the quaternary ammonium salt, ammonia water, an organic solvent (ethanol) and water.

[0036] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the silicon-containing compound in step (3) can be selected from one or more of methyl orthosilicate, ethyl orthosilicate, sodium silicate, and silica sol, and is preferably ethyl orthosilicate.

[0037] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the introduction of the active metal component in step (4) can be performed by impregnation, and preferably by stepwise impregnation, i.e., first introducing a first active metal component and then introducing a second active metal component.

[0038] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the process of introducing the active metal component in step (4) is as follows:

[0039] (4.1) Under mixing conditions, a solution of a precursor of a first active metal is added dropwise to the material C, and the addition is stopped when the material C just exhibits a flow phase, and then the sample is treated under vacuum conditions until no bubbles are generated in the sample, followed by stirring treatment, and the vacuum treatment and stirring treatment are repeated for several times, typically 3-5 times, and then the catalyst precursor is obtained after drying and calcination, and the drying is preferably performed under mixing conditions;

[0040] (4.2) Then a solution of a precursor of a second active metal is added dropwise to the catalyst precursor, and the sample is treated under vacuum conditions until no bubbles are generated in the sample, followed by stirring treatment, and the vacuum treatment and stirring treatment are repeated for several times, typically 2-4 times, and then the catalyst is obtained after drying and calcination, and the drying is preferably performed under mixing conditions.

[0041] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the precursor of the first active metal is a solution of an inorganic salt containing the first active metal, which can be one or more of a nickel nitrate, a cobalt nitrate, an iron nitrate, a ferric chloride, and a ferric sulfate, and is preferably one or more of a nickel nitrate, a cobalt nitrate, and an iron nitrate.

[0042] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the precursor of the second active metal is a solution of an organic acid salt containing the second active metal, and the organic acid salt is one or more of a magnesium gluconate, a magnesium lactate, and a magnesium citrate, and is preferably one or more of a magnesium gluconate and a calcium gluconate.

[0043] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the mixing in steps (4.1) and (4.2) can adopt at least one of the existing methods that can realize uniform mixing of materials, such as stirring.

[0044] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the stirring in steps (4.1) and (4.2) is preferably carried out under ultrasonic conditions, and more specifically, the ultrasonic conditions can be 40-60 kHz.

[0045] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the vacuum condition in steps (4.1) and (4.2) is generally controlled to maintain a vacuum degree of 0.05-0.1 MPa.

[0046] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the drying condition in step (4.1) is that the drying temperature is generally 60-100 ℃, and the drying time is 8-12 h; the calcination condition is that the calcination temperature is generally 400-600 ℃, and the calcination time is 4-6 h. The drying is preferably carried out under stirring condition.

[0047] Further, in the preparation method of the biomass conversion catalyst, as a specific embodiment, the drying condition in step (4.2) is that the drying temperature is generally 60-100 ℃, and the drying time is 8-12 h; the calcination condition is that the calcination temperature is generally 400-600 ℃, and the calcination time is 4-6 h. The drying is preferably carried out under stirring condition.

[0048] The third aspect of the present application provides an application of the biomass conversion catalyst or the biomass conversion catalyst obtained by the biomass conversion preparation method in a biomass conversion process.

[0049] The fourth aspect of the present application provides a lignin residue non-in-situ catalytic pyrolysis method, which contacts lignin residue materials with the biomass conversion catalyst or the biomass conversion catalyst obtained by the preparation method for reaction.

[0050] Compared with the prior art, the biomass conversion catalyst and the preparation method thereof provided by the present application have the following beneficial effects and technical advantages:

[0051] 1. The biomass conversion catalyst provided by the application has multiple functions of catalytic cracking, reforming and inhibiting carbon deposition, and is particularly suitable for use in the process of lignin residue non-in-situ catalytic pyrolysis. The catalyst can transfer the carbon deposition site in the catalytic reaction and inhibit the generation of carbon deposition reaction. The composite structure catalyst AT-ZSM-5@MCM-41 with microporous-disordered mesoporous as the core and ordered mesoporous as the shell is prepared by pretreating ZSM-5 molecular sieve and the like. The advantages of the acid sites and pore structure of the ZSM-5 molecular sieve catalyst are fully utilized. The microporous-mesoporous core structure and the distribution of acid sites are adjusted by changing the types, proportions and treatment time of the treating agent and the additive. The thickness of the ordered mesoporous shell and the total acid amount of the composite structure catalyst are adjusted by changing the proportion of the external silicon source and the core. The first active metal active phase is introduced into the microporous-mesoporous composite structure molecular sieve by using the equal-volume impregnation method, and the second active metal active phase is introduced into the mesoporous MCM-41. The number of active sites of the catalyst and the interaction between the active sites and the carrier are adjusted by changing the loading amount of the bimetallic active phase. By introducing the bimetallic active phase and combining the microporous-mesoporous composite structure, the catalyst has high selectivity for aromatic hydrocarbon target products and strong inhibition effect on by-product carbon deposition, so that the quality of liquid products is improved and the service life of the catalyst is prolonged.

[0052] 2. In the catalyst preparation method provided by the application, the long-chain quaternary ammonium salt is better adsorbed by the ZSM-5 molecular sieve pretreated and the additive through electrostatic interaction, so that the mesoporous MCM-41 is more uniformly coated, the dispersion effect of the second active metal phase in the MCM-41 is further improved, and the interaction between the second active metal component and the MCM-41 molecular sieve is enhanced.

[0053] 3. The catalyst preparation method provided by the application introduces the active metal component by using the combination of “step-by-step impregnation, vacuum extraction and ultrasonic treatment”, so that the metal active phase is highly dispersed and is mainly distributed in the microporous-mesoporous pore channel instead of the surface of the catalyst, which is beneficial to the regulation of the occurrence position of the catalytic reaction.

[0054] 4. In the catalyst preparation method provided by the application, the new active sites generated by the interaction between the second active metal component and the MCM-41 can change the generation position of the catalytic by-product carbon deposition. The BET pore structure parameter results show that the mesopore specific surface area reduction rate of the catalyst after the reaction is greater than that of the micropore after the introduction of the second active metal component, which indicates that more carbon deposition tends to be generated in the mesopore and has a certain protective effect on the micropore. Meanwhile, the way of introducing the second active metal component into the MCM-41 in the catalyst preparation method of the application is beneficial to improving the proportion of the second active metal component in the mesoporous pore channel.

[0055] 5. In the catalyst provided by this invention, the high dispersion of the first active metal can improve the catalytic activity of the catalyst, increase the yield of the target product monocyclic aromatic hydrocarbons, and reduce the amount of carbon deposits formed; the introduction of basic sites by the second active metal component can improve the decarbonylation ability of the catalyst and change the carbon deposit formation site. Furthermore, the combination of the first and second active metal components can significantly improve the catalytic performance of the catalyst, improve product quality, and contribute to extending the catalyst lifetime. Attached Figure Description

[0056] Figure 1 The chromatogram shows the liquid products after the thermal pyrolysis reaction of lignin residue in Comparative Example 1.

[0057] Figure 2 The chromatogram shows the liquid products after the non-in-situ catalytic pyrolysis of lignin residue in Comparative Example 3.

[0058] Figure 3 The chromatogram shows the liquid products after the non-in-situ catalytic pyrolysis of lignin residue in Comparative Example 4.

[0059] Figure 4 The image shows the chromatogram of the liquid product after the non-in-situ catalytic pyrolysis reaction of lignin residue in Example 5.

[0060] Figure 5 This is a comparison of the specific surface area loss rate of the catalyst micropores in the examples / comparative examples.

[0061] Figure 6 This is a comparison of the ratio of catalyst microporous specific surface area loss rate in the examples / comparative examples.

[0062] Figure 7 This is a schematic diagram of the biomass non-in-situ catalytic pyrolysis process of the present invention. Detailed Implementation

[0063] The specific content and effects of the method of the present invention will be further explained below through specific embodiments, but this does not limit the scope of the present invention.

[0064] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0065] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0066] When the specification states that a material, substance, process, step, apparatus or component etc. is "known to those of skill in the art", "presently known", "existing technologies", or the like, the disclosure is intended to incorporate by reference the teachings of each and every patent, scientific paper, and other publication relating to the art in which this application is classified.

[0067] Unless specifically stated otherwise, throughout this specification and claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements. In this document, all numerical values for parameters (e.g. amounts or conditions) are to be understood as modified in all instances by the term "about" unless otherwise indicated.

[0068] All percentages, parts, ratios, etc. stated in the specification and claims are meant to be understood as being pre-cise to the point allowed by the accuracy of the measurement.

[0069] In the context of this specification, any two or more embodiments of the application can be combined in any manner, and the technical solutions thus formed are part of the original disclosure of this specification and also fall within the protection scope of the application.

[0070] In the following examples and comparative examples, the specific conditions not noted are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments not noted by the manufacturer are the conventional products available on the market.

[0071] In this document, the nitrogen isothermal adsorption-desorption test is carried out by using the ASAP 2460 full-automatic specific surface and porosity analyzer, the specific surface area and pore volume of the catalyst are calculated by using the Brunauer-Emmett-Teller (BET) method, and the pore size distribution is obtained by using the Barrett-Joyner-Halenda (BJH) method.

[0072] In this document, the liquid product after the lignin residue non-in-situ catalytic pyrolysis reaction is analyzed by using the gas chromatography-mass spectrometry (GC / MS) instrument of the model of Thermo Scientific Trace DSQII.

[0073] Catalyst evaluation test:

[0074] The process flow is used to carry out the catalyst evaluation test by using the lignin residue as the raw material, and the specific content is as follows: Figure 7 The process flow is used to carry out the catalyst evaluation test by using the lignin residue as the raw material, and the specific content is as follows:

[0075] 1) The prepared catalyst was pressed into tablets, crushed, and sieved to obtain a catalyst powder with a particle size of 40-60 mesh;

[0076] 2) The lignin residue was loaded into the feed bin, and a mixture of 10 g of catalyst powder and an equal volume of quartz sand was loaded into the catalytic section reactor. Air in the device was discharged by passing carrier gas N2, and the pyrolysis section reactor was heated to 550°C, the coke tank was heated to 400°C, and the catalytic section reactor was heated to 600°C.

[0077] 3) After heating to the set temperature, the carrier gas flow rate was set to 600 mL / min, the feed rate of the feed bin was 5 g / h, the material entered the pyrolysis section reactor through the continuous feeding device, the pyrolysis byproduct coke was collected through the coke tank, and the primary pyrolysis gas entered the catalytic section reactor containing the above-prepared catalyst, and reacted for 2 h under the action of the catalyst.

[0078] 4) The liquid products were condensed using a condensing device, and qualitative and quantitative analysis of the liquid products was performed using GC / MS. The catalyst in the catalytic section reactor after the reaction was collected, and TG was used for qualitative and quantitative analysis of the solid products. The reacted catalyst was calcined at 500-800°C in an oxygen atmosphere for 1-3 h to remove carbon deposits. BET specific surface area analysis was performed on the catalyst before and after the reaction to characterize the effect of carbon deposition byproducts on the micropores and mesopores of the catalyst. The specific results are shown in Table 1.

[0079] Example 1

[0080] Catalyst preparation:

[0081] (1) Prepare 30 mL of 0.5 mol / L TEAOH alkali solution, add 1 g of ZSM-5 molecular sieve sample, heat and stir in a 70°C water bath, put into an ice water bath after 40 min, then filter, wash with deionized water, dry at 90°C for 12 h, and calcine at 600°C for 5 h to obtain AT1-Z.

[0082] (2) Prepare PDDA solution according to the ratio of PDDA: alcohol solution volume ratio of 12:13, wherein the PDDA concentration is 2 g / L, and the ethanol concentration in the alcohol solution is 20 wt.%. Add 1 g of AT1-Z sample to 30 mL of PDDA solution, stir to form a suspension, filter after 1.5 h of stirring, wash with deionized water, dry at 100°C for 6 h to obtain R1-AT1-Z.

[0083] (3) CTAB solution was prepared according to the ratio of CTAB:ammonia water: ethanol: deionized water = 1 g: 4 mL: 200 mL: 250 mL, and the concentration of ammonia water was 25 wt%. 1 g of R1-AT1-Z sample was added to 300 mL of CTAB solution, and ultrasonic oscillation, 35°C heating, and 600 rpm stirring were performed for 1 h. Then 1 g of methyl silicate was added dropwise to the solution while stirring at 35°C for 6 h. Filtration, deionized water washing, 90°C drying for 12 h, and 600°C calcination for 5 h were performed to obtain R1-AT1-Z@M1.

[0084] (4.1) A nickel nitrate solution with a Ni element content of 10 wt% was prepared, 1 g of R1-AT1-Z@M1 was weighed, 0.05 mL of nickel nitrate solution was added to R1-AT1-Z@M1, and the sample was stirred until no obvious unevenness was observed. The “solution dropwise addition + stirring” step was repeated until the sample just showed a flow phase, at which time a total of 1.45 mL of nickel nitrate solution was added. The sample was vacuumed (vacuum degree was 0.7 MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, and the “vacuum + ultrasonic oscillation” step was repeated 3 times. The sample was then dried at 90°C for 10 h and calcined at 600°C for 5 h to obtain 10Ni / R1-AT1-Z@M1.

[0085] (4.2) A magnesium gluconate solution with a Mg element content of 5 wt% was prepared, 1 g of 10Ni / R1-AT1-Z@M1 was weighed, and 0.05 mL of magnesium gluconate solution was added to 10Ni / R1-AT1-Z@M1. The sample was stirred until no obvious unevenness was observed. The “solution dropwise addition + stirring” step was repeated until the sample just showed a flow phase, at which time a total of 1.25 mL of magnesium gluconate solution was added. The sample was vacuumed (vacuum degree was 0.6 MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, and the “vacuum + ultrasonic oscillation” step was repeated 2 times. The sample was then dried at 80°C for 12 h and calcined at 550°C for 4 h to obtain 10Ni / R1-AT1-Z@5Mg / M1.

[0086] After the obtained catalyst was subjected to catalyst evaluation test, the results were as follows: the liquid product yield was 39.83 wt%, among which the target product monocyclic aromatic hydrocarbon yield was 9.56 wt%; the byproduct carbon deposition yield was 6.35 wt%.

[0087] Example 2

[0088] (1) 20 mL of TPAOH alkali solution with a concentration of 0.8 mol / L was prepared, 1 g of ZSM-5 molecular sieve sample was added, and the sample was heated and stirred in a 80°C water bath. After 30 min, the sample was quenched in an ice water bath, then filtration, deionized water washing, 105°C drying for 10 h, and 600°C calcination for 5 h were performed to obtain AT2-Z.

[0089] (2) PDDA solution was prepared according to the ratio of PVP: alcohol solution of 6:5, wherein the PVP concentration was 2.5 g / L, and the methanol concentration in the alcohol solution was 15 wt.%. 1 g of the AT2-Z sample was added to 30 mL of the PVP solution to form a suspension, which was stirred for 1.5 h, then filtered, washed with deionized water, and dried at 105°C for 5 h to obtain R2-AT2-Z.

[0090] (3) STAB solution was prepared according to the ratio of STAB: ammonia water: ethanol: deionized water of 1 g: 4 mL: 200 mL: 250 mL, wherein the ammonia water concentration was 25 wt.%. 1 g of the R2-AT2-Z sample was added to 300 mL of the STAB solution, and ultrasonic oscillation, 35°C heating, and 600 RPM stirring were performed for 1 h. Then 1 g of tetraethyl orthosilicate was added dropwise to the solution while stirring at 35°C for 6 h. Filtration, deionized water washing, drying at 90°C for 12 h, and calcination at 600°C for 5 h were performed to obtain R2-AT2-Z@M2.

[0091] (4.1) Cobalt nitrate solution with a Co element content of 10 wt.% was prepared, 1 g of R2-AT2-Z@M1 was weighed, 0.05 mL of the cobalt nitrate solution was added to the R2-AT2-Z@M1, and the sample was stirred until no obvious unevenness was observed. The “solution addition + stirring” step was repeated until the sample just showed a flowing phase, at which time a total of 1.6 mL of the cobalt nitrate solution was added. The sample was vacuumed (vacuum degree of 0.8 MPa) until no bubbles were generated in the sample, then ultrasonic oscillation was performed. The “vacuuming + ultrasonic oscillation” step was repeated 3 times, then the sample was dried at 90°C for 10 h and calcined at 600°C for 5 h to obtain 10Co / R2-AT2-Z@M2.

[0092] (4.2) Calcium lactate solution with a Ca element content of 7.5 wt.% was prepared, 1 g of 10Co / R2-AT2-Z@M2 was weighed, 0.05 mL of the calcium lactate solution was added to the 10Co / R2-AT2-Z@M2, and the sample was stirred until no obvious unevenness was observed. The “solution addition + stirring” step was repeated until the sample just showed a flowing phase, at which time a total of 1.45 mL of the calcium lactate solution was added. The sample was vacuumed (vacuum degree of 0.6 MPa) until no bubbles were generated in the sample, then ultrasonic oscillation was performed. The “vacuuming + ultrasonic oscillation” step was repeated 2 times, then the sample was dried at 90°C for 10 h and calcined at 550°C for 4 h to obtain 10Co / R2-AT2-Z@7.5Ca / M2.

[0093] The catalyst evaluation test was performed on the obtained catalyst, and the results were as follows: the liquid product yield was 40.72 wt%, of which the target product monocyclic aromatic hydrocarbon yield was 10.37 wt%; the byproduct carbon deposition yield was 5.39 wt%.

[0094] Example 3

[0095] (1) A 30 mL TBPOH alkali solution with a concentration of 0.5 mol / L was prepared, 1 g of ZSM-5 molecular sieve sample was added, and stirring was performed in a water bath at 80°C. After 30 min, the sample was quenched in an ice water bath, and then filtration, deionized water washing, drying at 105°C for 8 h, and calcination at 600°C for 5 h were performed to obtain AT3-Z.

[0096] (2) A PDDA solution was prepared according to a PDDA: alcohol solution volume ratio of 8:7, wherein the PDDA concentration was 3 g / L, and the ethanol concentration in the alcohol solution was 10 wt%. 1 g of the AT3-Z sample was added to 30 mL of the PDDA solution to form a suspension, which was stirred for 1.5 h, and then filtration, deionized water washing, and drying at 100°C for 8 h were performed to obtain R3-AT3-Z.

[0097] (3) A CTAB solution was prepared according to a CTAB: ammonia water: ethanol: deionized water ratio of 1 g: 4 mL: 200 mL: 250 mL, wherein the ammonia water concentration was 25 wt%. 1 g of the R3-AT3-Z sample was added to 300 mL of the CTAB solution, and ultrasonic oscillation, heating at 35°C, and stirring at 600 RPM were performed for 1 h. Then, 2 g of tetraethyl orthosilicate was added dropwise to the solution while stirring at 35°C for 6 h. Filtration, deionized water washing, drying at 90°C for 12 h, and calcination at 600°C for 5 h were performed to obtain R3-AT3-Z@M3.

[0098] (4.1) An iron chloride solution with an Fe element content of 8 wt% was prepared, 1 g of the R3-AT3-Z@M3 was weighed, 0.05 mL of the iron chloride solution was added dropwise to the R3-AT3-Z@M3, and sufficient stirring was performed until no obvious unevenness was observed. The “solution dropwise addition + stirring” step was repeated until the catalyst sample just showed a flow phase, at which time a total of 1.55 mL of the iron chloride solution was added. The sample was vacuumized (vacuum degree: 0.7 MPa) until no bubbles were generated in the sample, and then ultrasonic oscillation was performed. After the “vacuumization + ultrasonic oscillation” step was repeated 3 times, the sample was dried at 90°C for 12 h and calcined at 600°C for 5 h to obtain 8Fe / R3-AT3-Z@M3.

[0099] (4.2) Preparation of a magnesium lactate solution with a Mg element content of 7.5wt%, 1g of 8Fe / R3-AT3-Z@M3 is weighed, 0.05mL of the magnesium lactate solution is added dropwise to the 8Fe / R3-AT3-Z@M3, and the solution is stirred until no obvious unevenness is observed, and the steps of "adding solution dropwise + stirring" are repeated until the catalyst sample just shows a flow phase, at which time a total of 1.5mL of the magnesium lactate solution is added. The sample is vacuumed (vacuum degree of 0.5MPa) until no bubbles are generated in the sample, and then the sample is subjected to ultrasonic oscillation, and the "vacuuming + ultrasonic oscillation" is repeated twice, and then the sample is dried at 90°C for 12h and calcined at 600°C for 4h to obtain 8Fe / R3-AT3-Z@7.5Mg / M3.

[0100] After the obtained catalyst is subjected to catalyst evaluation test, the results are as follows: the liquid product yield is 41.63wt%, and the yield of the target product monocyclic aromatic hydrocarbon is 10.16wt%; the yield of the byproduct carbon deposit is 5.23wt%.

[0101] Example 4

[0102] (1) A 40mL TBPOH base solution with a concentration of 1mol / L is prepared, and 1g of ZSM-5 molecular sieve sample is added, heated and stirred in a 60°C water bath, and after 30min, the sample is placed in an ice water bath for quenching, and then filtered, washed with deionized water, dried at 100°C for 12h, and calcined at 600°C for 5h to obtain AT4-Z.

[0103] (2) A PDDA solution is prepared according to a PDDA:alcohol solution volume ratio of 10:9, wherein the PDDA concentration is 2.5g / L, and the propanol concentration in the alcohol solution is 7.5wt%. 1g of the AT4-Z sample is added to 30mL of the PDDA solution to form a suspension, and after stirring for 1.5h, the sample is filtered, washed with deionized water, and dried at 100°C for 12h to obtain R4-AT4-Z.

[0104] (3) A TTAB solution is prepared according to a TTAB:ammonia water:ethanol:deionized water ratio of 1g:4mL:200mL:250mL, wherein the ammonia water concentration is 25wt%. 1g of the R4-AT4-Z sample is added to 300mL of the TTAB solution, and ultrasonic oscillation, 35°C heating, and 600RPm stirring are simultaneously performed for 1h. Then, 1g of methyl silicate is added dropwise to the solution while stirring at 35°C for 6h. The sample is filtered, washed with deionized water, dried at 90°C for 12h, and calcined at 600°C for 5h to obtain R4-AT4-Z@M4.

[0105] (4.1) A nickel nitrate solution with a Ni element content of 20wt% was prepared, 1g of R4-AT4-Z@M4 was weighed, 0.05mL of the nickel nitrate solution was added dropwise to the R4-AT4-Z@M4, and the mixture was stirred thoroughly until no obvious unevenness was observed, the steps of "adding solution dropwise + stirring" were repeated until the catalyst sample just showed a flowing phase, at this time a total of 1.7mL of the nickel nitrate solution was added. The sample was vacuumed (the vacuum degree was 0.9MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, the steps of "vacuuming + ultrasonic oscillation" were repeated for 3 times, then the sample was dried at 90℃ for 12h and calcined at 600℃ for 5h to obtain 20Ni / R4-AT4-Z@M4.

[0106] (4.2) A calcium gluconate solution with a Ca element content of 5wt% was prepared in a beaker, 1g of 20Ni / R4-AT4-Z@M4 was weighed, 0.05mL of the calcium gluconate solution was added dropwise to the 20Ni / R4-AT4-Z@M4, and the mixture was stirred thoroughly until no obvious unevenness was observed, the steps of "adding solution dropwise + stirring" were repeated until the catalyst sample just showed a flowing phase, at this time a total of 1.2mL of the calcium gluconate solution was added. The sample was vacuumed (the vacuum degree was 0.6MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, the steps of "vacuuming + ultrasonic oscillation" were repeated for 2 times, then the sample was dried at 80℃ for 12h and calcined at 600℃ for 4h to obtain 20Ni / R4-AT4-Z@5Ca / M4.

[0107] After the obtained catalyst was subjected to catalyst evaluation test, the results were as follows: the liquid product yield was 45.39wt%, among which the yield of the target product monocyclic aromatic hydrocarbon was 12.94wt%, and the yield of the byproduct carbon was 3.48wt%.

[0108] Example 5

[0109] (1) A 30mL TPAOH alkali solution with a concentration of 0.5mol / L was prepared, 1g of ZSM-5 molecular sieve sample was added, and the mixture was heated and stirred in a 80℃ water bath, then was placed in an ice water bath for quenching after 40min, then was subjected to filtration, deionized water washing, drying at 100℃ for 10h, and calcination at 600℃ for 5h to obtain AT5-Z.

[0110] (2) A PDDA solution was prepared according to a PDDA:alcohol solution volume ratio of 5:9, wherein the PDDA concentration was 2g / L, and the ethanol concentration in the alcohol solution was 6wt%. 1g of the AT5-Z sample was added to 30mL of the PDDA solution to form a suspension, and the mixture was stirred for 1.5h, then was subjected to filtration, deionized water washing, and drying at 100℃ for 12h to obtain R5-AT5-Z.

[0111] (3) CTAB solution was prepared according to the ratio of CTAB:ammonia water:ethanol:deionized water of 1 g:4 mL:200 mL:250 mL, wherein the ammonia water concentration was 25 wt%. 1 g of R5-AT5-Z sample was added to 300 mL of CTAB solution, while ultrasonic oscillation, 35°C heating, and 600 RPM stirring were carried out for 1 h. Then 1 g of tetraethyl orthosilicate was added dropwise to the solution while stirring at 35°C for 6 h. Filtration, deionized water washing, 90°C drying for 12 h, and 600°C calcination for 5 h were carried out to obtain R5-AT5-Z@M5.

[0112] (4.1) A nickel nitrate solution with a Ni element content of 20 wt% was prepared, 1 g of R5-AT5-Z@M5 was weighed, 0.05 mL of nickel nitrate solution was added to R5-AT5-Z@M5, and the sample was stirred until no obvious unevenness was observed, the steps of “adding solution + stirring” were repeated until the catalyst sample just showed a flowing phase, at this time a total of 1.65 mL of nickel nitrate solution was added. The sample was vacuumed (vacuum degree of 0.8 MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, and after repeating the “vacuuming + ultrasonic oscillation” for 3 times, the sample was subjected to 90°C drying for 10 h and 600°C calcination for 5 h to obtain 20Ni / R5-AT5-Z@M5.

[0113] (4.2) A magnesium gluconate solution with a Mg element content of 7.5 wt% was prepared, 1 g of 20Ni / R5-AT5-Z@M5 was weighed, 0.05 mL of magnesium gluconate solution was added to 20Ni / R5-AT5-Z@M5, and the sample was stirred until no obvious unevenness was observed, the steps of “adding solution + stirring” were repeated until the catalyst sample just showed a flowing phase, at this time a total of 1.45 mL of magnesium gluconate solution was added. The sample was vacuumed (vacuum degree of 0.5 MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, and after repeating the “vacuuming + ultrasonic oscillation” for 2 times, the sample was subjected to 90°C drying for 10 h and 500°C calcination for 4 h to obtain 20Ni / R5-AT5-Z@7.5Mg / M5.

[0114] After the obtained catalyst was subjected to catalyst evaluation test, the results were as follows: the liquid product yield was 45.78 wt%, among which the yield of the target product monocyclic aromatic hydrocarbon was 13.21 wt%, and the yield of the byproduct carbon was 3.01 wt%.

[0115] Figure 4Chromatogram analysis of liquid product after in-situ catalytic pyrolysis of lignin residue in Example 5: GC / MS product after in-situ catalytic pyrolysis of lignin residue under the catalysis of 20Ni / R5-AT5-Z@7.5Mg / M5 catalyst includes target product monocyclic aromatic hydrocarbon (benzene, toluene, xylene), polycyclic aromatic hydrocarbon (naphthalene, methylnaphthalene), phenol and dimethylphenol. Compared with 20Ni / R5-AT5-Z@M5 catalyst, 20Ni / R5-AT5-Z@7.5Mg / M5 catalyst has appropriate degree of aromatization, further increases the selectivity of monocyclic aromatic hydrocarbon in product, and also inhibits polycyclic aromatic hydrocarbon to a certain extent, which matches the decrease of carbon deposition yield as mentioned above. Due to the introduction of Mg active phase, which brings alkaline sites, it can inhibit enone substances to further generate carbon deposition precursors; oxygen-containing products are mainly composed of phenolic substances containing only one O, including phenol and dimethylphenol, and multi-side chain phenolic substances are greatly reduced, and the deoxygenation ability and alkylation effect are better than 20Ni / R5-AT5-Z@M5 and R5-AT5-Z@M5 catalysts.

[0116] Example 6

[0117] (1) Prepare 40 mL of 0.3 mol / L TEAOH alkali solution, add 1 g of ZSM-5 molecular sieve sample, heat and stir in a 60°C water bath, put into an ice water bath after 40 min, then filter, wash with deionized water, dry at 100°C for 12 h, and calcine at 600°C for 5 h to obtain AT6-Z.

[0118] (2) Prepare PVP solution according to the ratio of PVP: alcohol solution volume ratio of 3:5, wherein the PVP concentration is 2 g / L, and the ethanol concentration in the alcohol solution is 25 wt.%. Add 1 g of AT6-Z sample to 30 mL of PVP solution to form a suspension, stir for 1.5 h, then filter, wash with deionized water, dry at 100°C for 12 h to obtain R6-AT6-Z.

[0119] (3) Prepare CTAB solution in a conical flask according to the ratio of CTAB: ammonia: ethanol: deionized water of 1 g: 4 mL: 200 mL: 250 mL, wherein the ammonia concentration is 25 wt.%. Add 1 g of R6-AT6-Z sample to 300 mL of CTAB solution, and perform ultrasonic oscillation, 35°C heating, and 600 RPM stirring for 1 h. Then add 2 g of methyl silicate dropwise to the solution in the conical flask while stirring at 35°C for 6 h. Filter, wash with deionized water, dry at 90°C for 12 h, and calcine at 600°C for 5 h to obtain R6-AT6-Z@M6.

[0120] (4.1) Preparation of an iron sulfate solution with an Fe element content of 15wt%, 1g of R6-AT6-Z@M6 was weighed, 0.05mL of the iron sulfate solution was added dropwise to the R6-AT6-Z@M6, and the mixture was stirred until no obvious unevenness was observed, the step of "adding solution dropwise + stirring" was repeated until the catalyst sample just showed a flow phase, at this time the total amount of iron sulfate solution added was 1.7mL. The sample was vacuumed (vacuum degree was 0.7MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, the "vacuuming + ultrasonic oscillation" was repeated for 3 times, then the sample was dried at 70℃ for 12h and calcined at 600℃ for 5h to obtain 15Fe / R6-AT6-Z@M6.

[0121] (4.2) Preparation of a magnesium citrate solution with a Mg element content of 12.5wt%, 1g of 15Fe / R6-AT6-Z@M6 was weighed, 0.05mL of the magnesium citrate solution was added dropwise to the 15Fe / R6-AT6-Z@M6, and the mixture was stirred until no obvious unevenness was observed, the step of "adding solution dropwise + stirring" was repeated until the catalyst sample just showed a flow phase, at this time the total amount of magnesium citrate solution added was 1.6mL. The sample was vacuumed (vacuum degree was 0.6MPa) until no bubbles were generated in the sample, then the sample was subjected to ultrasonic oscillation, the "vacuuming + ultrasonic oscillation" was repeated for 2 times, then the sample was dried at 90℃ for 12h and calcined at 600℃ for 5h to obtain 15Fe / R6-AT6-Z@12.5Mg / M6.

[0122] After the obtained catalyst was subjected to catalyst evaluation test, the results were as follows: the liquid product yield was 42.15wt%, among which the yield of the target product monocyclic aromatic hydrocarbon was 11.32wt%, and the yield of the byproduct carbon was 3.89wt%.

[0123] Comparative Example 1

[0124] In Comparative Example 1, no catalyst was loaded, only quartz sand was loaded. The lignin residue material was loaded in the feed bin, 10 g of quartz sand was loaded in the catalytic section reactor, air in the reaction device was discharged by passing carrier gas N2, and the pyrolysis section reactor was heated to 550°C, the coke tank was heated to 400°C, and the catalytic section reactor was heated to 600°C. After heating to the set temperature, the carrier gas flow rate was set to 600 mL / min, the feed rate of the feed bin was 5 g / h, the material entered the pyrolysis section reactor through the continuous feeding device, the pyrolysis byproduct coke was collected through the coke tank, and the primary pyrolysis gas entered the catalytic section reactor loaded with quartz sand. The reaction time was 2 h. A three-stage condensing device was used to condense the liquid products, and GC / MS was used for qualitative and quantitative analysis of the liquid products. The catalyst in the catalytic section reactor after the reaction was collected, and TG was used for qualitative and quantitative analysis of the solid products. The results after the evaluation test were as follows: the liquid product yield was 55.65 wt%, and the yield of the target product monocyclic aromatic hydrocarbon was 0.37 wt%.

[0125] Figure 1 Analysis of the chromatogram of the liquid product after the lignin residue pyrolysis reaction (Comparative Example 1): Under the condition of no catalyst, the GC / MS pyrolysis products of lignin residue at a temperature of 550°C were mainly phenolic substances containing alkyl, alkoxy, and alkenyl side chains. In the pyrolysis without catalyst, the β-O-4 bond of the lignin macromolecule mainly broke to generate phenols with multiple side chains.

[0126] Comparative Example 2

[0127] AT5-Z prepared by step (1) in Example 5 was used as the catalyst, and the results after the evaluation test were as follows: the liquid product yield was 38.91 wt%, the yield of the target product monocyclic aromatic hydrocarbon was 7.35 wt%, and the byproduct coke yield was 6.37 wt%.

[0128] Comparative Example 3

[0129] R5-AT5-Z@M5 prepared by steps (1)-(3) in Example 5 was used as the catalyst, and the results after the evaluation test were as follows: the liquid product yield was 38.78 wt%, the yield of the target product monocyclic aromatic hydrocarbon was 8.12 wt%, and the byproduct coke yield was 6.29 wt%.

[0130] Figure 2Lignin residue non- in situ catalytic pyrolysis reaction after liquid product chromatogram (comparative example 3) analysis: under the catalysis of R5-AT5-Z@M5, the GC / MS product after lignin residue non- in situ catalytic pyrolysis includes target product monocyclic aromatic hydrocarbon (benzene, toluene, xylene), polycyclic aromatic hydrocarbon (naphthalene, methylnaphthalene), phenol and phenolic substances containing alkyl side chain. R5-AT5-Z@M5 catalyst has aromatization ability and deoxygenation ability, and a large amount of monocyclic aromatic hydrocarbon substances are generated, but the content of polycyclic aromatic hydrocarbon also increases accordingly; the oxygen-containing substances are mainly composed of phenolic substances containing only one O, and the selectivity of phenolic substances with multiple alkyl side chains (tetramethylphenol) is high, indicating that the alkylation effect is poor.

[0131] Comparative example 4

[0132] Using 20Ni / R5-AT5-Z@M5 prepared by steps (1) ~ (4.1) in example 5 as catalyst, the evaluation test results are as follows: the liquid product yield is 39.72wt%, and the target product monocyclic aromatic hydrocarbon yield is 10.22wt%; the byproduct carbon deposition yield is 4.19wt%.

[0133] Figure 3 Lignin residue non- in situ catalytic pyrolysis reaction after liquid product chromatogram (comparative example 4) analysis: under the catalysis of 20Ni / R5-AT5-Z@M5 catalyst, the GC / MS product after lignin residue non- in situ catalytic pyrolysis includes target product monocyclic aromatic hydrocarbon (benzene, toluene, xylene), polycyclic aromatic hydrocarbon (naphthalene, methylnaphthalene), phenol and phenolic substances containing alkyl side chain. Compared with R5-AT5-Z@M5 catalyst, the deoxygenation ability of 20Ni / R5-AT5-Z@M5 catalyst is greatly improved, the selectivity of oxygen-containing phenolic substances in the liquid product is greatly reduced, the content of phenolic substances with multiple alkyl side chains is reduced, and the alkylation effect is improved. However, there are still a large amount of polycyclic aromatic hydrocarbon substances in the product, which is easy to generate carbon deposition precursor or carbon deposition, which is not conducive to the improvement of the quality of the catalytic product.

[0134] Comparative example 5

[0135] Using R5-AT5-Z@7.5Mg / M5 prepared by steps (1) ~ (3), (4.2) in example 5 as catalyst, the evaluation test results are as follows: the liquid product yield is 38.10wt%, and the target product monocyclic aromatic hydrocarbon yield is 8.81wt%; the byproduct carbon deposition yield is 4.99wt%.

[0136] Comparative example 6

[0137] The 20Ni / AT5-Z@7.5Mg / M5 prepared by steps (1), (3)-(4.2) in Example 5 was used as catalyst, and the results after evaluation test were as follows: the liquid product yield was 39.26wt%, in which the target product monocyclic aromatic hydrocarbon yield was 12.26wt%; the by-product carbon deposition yield was 3.76wt%.

[0138] Table 1 Comparison of pore structure parameters of catalysts before and after non- in situ catalytic pyrolysis reaction

[0139]

[0140] Figure 6 The ratio of micropore-mesopore specific surface area loss rate of catalysts in different examples / comparative examples was compared; according to the change of micropore-mesopore specific surface area of catalysts before and after reaction, the change of carbon deposition position could be judged. The micropore specific surface area of 20Ni / R5-AT5-Z@7.5Mg / M5 catalyst in Example 5 decreased by 14.96%, and the mesopore specific surface area decreased by 20.16%, and the ratio of micropore-mesopore specific surface area loss rate was 0.74, which was the lowest among several examples / comparative examples, indicating that under the catalysis of 20Ni / R5-AT5-Z@7.5Mg / M5 catalyst, the influence of carbon deposition on mesopore specific surface area was greater than that on micropore, and more by-product carbon deposition was generated in mesopore, which had a protective mechanism on the active sites in micropore, and was beneficial to improve the catalytic performance and prolong the service life of catalyst, which matched the results that the selectivity of target product monocyclic aromatic hydrocarbon in liquid product was greatly improved, and the selectivity of polycyclic aromatic hydrocarbon was low.

[0141] Wherein, S BET and V Total represent the BET specific surface area and total pore volume calculated by Brunauer-Emmett-Teller (BET) method; S micro and V micro are micropore specific surface area and pore volume calculated by t-Plot method; S meso and V meso represent mesopore specific surface area and pore volume.

Claims

1. A biomass conversion catalyst, the catalyst comprising a support and an active metal component, the active metal component being distributed on the surface and in the pores of the support; the support being a core-shell structure comprising a core and a shell, the core being a ZSM-5 molecular sieve containing both micropores and mesopores, the shell being a mesoporous MCM-41 molecular sieve; the active metal component comprising a first active metal component and a second active metal component, wherein the first active metal is at least one of the Group VIII elements, the Group VIII elements being one or more of Ni, Co, Fe; the second active metal being an alkaline earth metal, the alkaline earth metal being one or more of Mg, Ca; the active metal component being in the form of metal oxides; the support content being 70wt%-80wt% based on the weight of the catalyst, the first active metal content being 10wt%-20wt% as oxides, the second active metal component content being 5wt%-15wt% as oxides; the first active metal component being concentrated in the pores of the support; the second active metal component being mainly distributed in the pores of the shell mesoporous MCM-41 molecular sieve; the total amount of acid sites of the catalyst being 850-1200μmol / g, the ratio of B acid to L acid being 0.70-3.

50.

2. The biomass conversion catalyst according to claim 1, characterized by: The first active metal is Ni, and the second active metal is Mg.

3. The biomass conversion catalyst according to claim 1, characterized by: The catalyst has a core-shell structure, the mesoporous shell layer has a thickness of 10-30nm, and the mesoporous layer is uniformly coated.

4. The biomass conversion catalyst according to claim 1, characterized by: The average pore diameter of the catalyst is 2.5-9.5nm.

5. The biomass conversion catalyst according to claim 1, wherein: The average pore diameter of the catalyst is 3.5-6.5nm.

6. The biomass conversion catalyst according to claim 1, wherein: The total amount of acid sites of the catalyst is 950-1050μmol / g, and the ratio of B acid to L acid is 1.20-2.

90.

7. The biomass conversion catalyst according to claim 1, wherein: The specific surface area of the catalyst is 450-800 m 2 / g.

8. The biomass conversion catalyst according to claim 1, wherein: The specific surface area of the catalyst is 500-650 m 2 / g.

9. The biomass conversion catalyst according to claim 1, wherein: The catalyst has a pore volume of 0.40 to 0.80 cm3 / g. 3 / g.

10. The biomass conversion catalyst according to claim 1, wherein: The catalyst has a pore volume of 0.55 to 0.75 cm3 / g. 3 / g. 11.A method for preparing a biomass conversion catalyst, comprising the following steps: (1) contacting a ZSM-5 molecular sieve with a treating agent under contact conditions to perform treatment, quenching the material after the treatment is completed, and further separating, washing, drying and calcining to obtain a material A; the treating agent is a quaternary ammonium base; the treating agent is one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide; the treatment temperature is 60-80℃, and the mass ratio of the ZSM-5 molecular sieve to the treating agent is 1:10-1:50; the calcination temperature is 550-650℃, the calcination time is 4-6h, and the calcination is performed in an oxygen-containing atmosphere; (2) mixing the material A obtained in step (1), an auxiliary agent and a solvent uniformly under mixing conditions, and then separating, washing and drying to obtain a material B; the auxiliary agent is one or more of polydimethyl diallyl ammonium chloride (PDDA) and polyvinylpyrrolidone (PVP); the solvent is an organic solvent and an inorganic solvent, the organic solvent is an alcohol solution, and the inorganic solvent is an inorganic salt solution. (3) mixing the material B obtained in step (2), a long-chain quaternary ammonium salt solution and a silicon-containing compound to react, and then separating, washing, drying and calcining to obtain a material C; the long-chain quaternary ammonium salt is one or more of dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), cetyltrimethylammonium bromide (CTAB) and octadecyltrimethylammonium bromide (STAB); (4) introducing an active metal component into the material C obtained in step (3) to obtain a biomass conversion catalyst.

12. The method of making a biomass conversion catalyst according to claim 11, wherein: The treating agent in step (1) is at least one of tetraethylammonium hydroxide and tetrapropylammonium hydroxide.

13. The method of making a biomass conversion catalyst according to claim 11, wherein: The quenching temperature in step (1) is 0-10℃.

14. The method of making a biomass conversion catalyst according to claim 11, wherein: The drying in step (1) is performed at 90-110℃ for 6-12h.

15. The method of making a biomass conversion catalyst according to claim 11, wherein: The additive in step (2) is polydimethyl diallyl ammonium chloride.

16. The method of making a biomass conversion catalyst according to claim 11, wherein: The organic solvent is an alcohol solution with carbon number of 1-4, and is at least one of methanol, ethanol and propanol; the concentration of the alcohol solution is 5wt%-25wt%; the inorganic solvent is one or more of sodium chloride solution and calcium chloride solution.

17. The method of making a biomass conversion catalyst according to claim 11 or 16, characterized by: The organic solvent is ethanol.

18. The method of making a biomass conversion catalyst according to claim 11, wherein: The drying in step (2) is performed at 90-110℃ for 4-8h.

19. The method of making a biomass conversion catalyst according to claim 11, wherein: The long-chain quaternary ammonium salt in step (3) is cetyltrimethylammonium bromide.

20. The method of making a biomass conversion catalyst according to claim 11, wherein: The silicon-containing compound in step (3) is one or more of methyl orthosilicate, ethyl orthosilicate, sodium silicate and silica sol.

21. The method of making a biomass conversion catalyst according to claim 11, wherein: The silicon-containing compound in step (3) is ethyl orthosilicate.

22. The method of making a biomass conversion catalyst according to claim 11, wherein: The introduction of the active metal component in step (4) is performed by stepwise impregnation, i.e. first introducing a first active metal component, and then introducing a second active metal component.

23. The method of making a biomass conversion catalyst according to claim 22, wherein: The process of introducing the active metal component in step (4) is as follows: (4.1) under mixing conditions, a first active metal precursor solution is added dropwise into the material C until the material C just presents a flow phase, then the first active metal precursor solution is stopped, and then the sample is treated under vacuum conditions until no bubbles are generated in the sample, followed by stirring treatment, and the treatment under vacuum conditions and the stirring treatment are repeated for several times, and then a catalyst precursor is obtained by drying and calcining, and the drying is performed under mixing conditions; (4.2) then a second active metal precursor solution is added dropwise into the catalyst precursor, and then the sample is treated under vacuum conditions until no bubbles are generated in the sample, followed by stirring treatment, and the treatment under vacuum conditions and the stirring treatment are repeated for several times, and then a catalyst is obtained by drying and calcining, and the drying is performed under mixing conditions.

24. The method of making a biomass conversion catalyst according to claim 23, wherein: The first active metal precursor is an inorganic salt solution containing a first active metal, and the inorganic salt is one or more of nitrate, hydrochloride and sulfate.

25. A process for the preparation of a biomass conversion catalyst according to claim 23 or 24 characterised in that: The first active metal precursor is one or more of nickel nitrate, cobalt nitrate, iron nitrate, iron chloride and iron sulfate.

26. The method of producing a biomass conversion catalyst according to claim 23 or 24, characterized by: The first active metal precursor is one or more of nickel nitrate, cobalt nitrate and iron nitrate.

27. The method of making a biomass conversion catalyst according to claim 23, wherein: The second active metal precursor is an organic acid salt solution containing a second active metal, and the organic acid salt is one or more of gluconate, lactate and citrate.

28. The method of making a biomass conversion catalyst according to claim 23 or 27, wherein: The precursor of the second active metal is selected from one or more of magnesium gluconate, magnesium lactate, magnesium citrate, calcium gluconate, calcium lactate.

29. The method of producing a biomass conversion catalyst according to claim 23 or 27, characterized by: The precursor of the second active metal is selected from one or more of magnesium gluconate, calcium gluconate.

30. The method of making a biomass conversion catalyst according to claim 23, wherein: The vacuum condition control in steps (4.1) and (4.2) keeps the vacuum degree at 0.05-0.1 MPa.

31. The method of making a biomass conversion catalyst according to claim 23, wherein: The drying temperature in steps (4.1) and (4.2) is 60-100°C, and the calcination temperature is 400-600°C.

32. Use of a biomass conversion catalyst according to any one of claims 1-10 or a biomass conversion catalyst obtained by a biomass conversion process according to any one of claims 11-31 in a biomass conversion process.

33. A method for the non-in situ catalytic pyrolysis of lignin residue, wherein a lignin residue material is contacted with a biomass conversion catalyst according to any one of claims 1-10 or a biomass conversion catalyst obtained by a biomass conversion process according to any one of claims 11-31 and reacted.

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