CN110923001B

CN110923001B - Method for preparing special fuel with low freezing point, high density and high thermal stability by using lignocellulose biomass

Info

Publication number: CN110923001B
Application number: CN201911162727.9A
Authority: CN
Inventors: 马隆龙; 张兴华; 王晨光; 张琦; 刘琪英; 陈伦刚; 刘建国
Original assignee: Guangzhou Institute of Energy Conversion of CAS
Current assignee: Guangzhou Institute of Energy Conversion of CAS
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2021-07-06
Anticipated expiration: 2039-11-25
Also published as: CN110923001A

Abstract

The invention provides a method for preparing a special fuel with low freezing point, high density and high thermal stability by using lignocellulose biomass. The method mainly comprises three steps: 1) hemicellulose and cellulose in the biomass raw material are converted into aldehyde and ketone (containing cyclic ketone substances) platform compounds through steam stripping and hydrolysis, and then the platform compounds are subjected to directional cross condensation and hydrodeoxygenation to synthesize low-freezing-point aviation oil components with components such as direct-connected hydrocarbon, branched chain isomeric hydrocarbon and cyclic chain isomeric hydrocarbon with carbon chain lengths of 8-17 as main components; 2) synthesizing a high-density aviation oil component by self-condensation and hydrodeoxygenation of a cyclic ketone platform compound; 3) the cyclohexane components with high chemical heat sink property and the additive components resisting thermal oxidation are prepared by directional depolymerization and conversion of lignin. On the basis, the biomass special fuel with low freezing point, high density and high heat-sinking characteristic is obtained through component blending and hydrofining, thereby meeting the requirement of rapid development of high-performance aircrafts in China.

Description

Method for preparing special fuel with low freezing point, high density and high thermal stability by using lignocellulose biomass

Technical Field

The invention belongs to the technical field of biomass resource utilization and biomass liquid fuel and aviation fuel preparation, and particularly relates to a method for directionally preparing a special fuel with low freezing point, high density and high thermal stability from a lignocellulose biomass raw material through various platform compounds.

Background

Modern aircrafts have higher and higher requirements on performance indexes such as load, navigational speed, range, flight altitude and the like, so that higher requirements are also put forward on fuels used by the aircrafts. Wherein increasing the density, volumetric heating value of the fuel is an important way to increase the propulsion performance of an aircraft at low cost. Under the condition of a certain volume of the fuel tank, the higher the fuel density and the larger the volumetric heat value, the farther the aircraft voyage. Cruise missiles or high performance fighters are the main application targets for high density fuels. The high-density aerospace fuel has the characteristic of high volume heat value, and has strict requirements on performance indexes of the fuel, such as freezing point, viscosity, flash point, heat stability, heat sink and the like. For example, in order to meet the requirements of severe cold weather and working environment at high altitude and low temperature, the fuel is required to have excellent low-temperature flow performance, namely, lower freezing point and viscosity; in order to overcome the high temperature problem caused by pneumatic heating when missiles and rockets fly at hypersonic speed, the fuel is required to have excellent heat sink and thermal stability. The density of the high-density special fuel is generally more than 0.80g/cm³Generally, the propellant is prepared by compounding a plurality of hydrocarbons and is a high-performance hydrocarbon propellant. High density fuels can be divided into the following two broad categories according to source and access:

(1) kerosene with large specific gravity. The major components of the large-specific gravity kerosene are alkane and naphthenic substances, and the kerosene is a fraction of a large-density oil refining product with a specific boiling range distribution or a product obtained by adding cycloalkane into the kerosene, and mainly represents U.S. Jet-A, JP4, JP-5, JP-7, JP-8 and Russian T series fuels. However, this type of fuel has a maximum density of only 0.85g/cm due to the restrictions of the crude oil composition³And the volume combustion heat value is usually lower than 37MJ/L, so that the increasing use requirements of modern military are difficult to meet. In addition, the thermal stability of the large-specific-gravity kerosene is poor, and the use temperature is not high enough, for example, the maximum use temperature of JP-8 is only 160 ℃, so that the requirements of rapidly developing aerospace and national defense industries cannot be met.

(2) Synthesized high density fuel. At present, specific hydrocarbon compounds derived from fossil raw materials are mainly used as main raw materials, such as cyclopentadiene, dicyclopentadiene, norbornadiene, adamantane and the like, and high-density fuels are prepared through processes of polymerization, hydrogenation, isomerization, separation, purification, compounding and the like, and the representative products mainly comprise JP-10, RJ-4I, RJ-5 and the like. Research shows that as the carbon number and the ring number of the hydrocarbon increase, the density of the hydrocarbon also increases, and the density of the naphthenic hydrocarbon with the same carbon number is higher than that of the chain hydrocarbon. Alkyl substituents also have a large effect on the freezing point and viscosity of hydrocarbons, and there is a large difference in physical properties between isomers of the same molecular weight. Therefore, the comprehensive performance of the high-density fuel can be adjusted by changing the carbon number and the ring number of the hydrocarbon, introducing alkyl substituent, changing the spatial configuration and the like, and finally the fuel with high density, high heat value, low freezing point and the like can be obtained. Compared with the large-specific gravity kerosene refined by crude oil, the directionally synthesized high-density fuel has wider research space on the regulation and control of performance indexes such as density, volume heat value and the like. The synthesis of new high density fuels has become a research focus.

Many kinds of high-density fuels (0.93-1.21g/mL) have been synthesized based on fossil raw materials, and some of the high-density fuels having stable quality have been put into practical use. However, because the raw material functional group of the petroleum-based platform compound is single, most of the fuel molecules are prepared by the platform substance containing olefin groups through D-A reaction, the structure regulation and control means of the fuel molecules are insufficient, the improvement space of the characteristic indexes of the fuel, such as density, heat value, stability, freezing point and the like, is limited, and the requirement of the current aerospace craft on rapid development cannot be met.

Disclosure of Invention

The invention aims to provide a method for preparing a special fuel with low freezing point, high density and high thermal stability by using a lignocellulose biomass, aiming at the defects in the prior art.

In order to achieve the above purpose, the invention provides the following technical scheme:

a method for preparing a special fuel with low freezing point, high density and high thermal stability by using lignocellulose biomass comprises the following steps:

1) sequentially converting hemicellulose and cellulose components in the lignocellulose biomass raw material into furfural and 5-hydroxymethylfurfural through hydrothermal directional depolymerization;

2) preparing an oxygen-containing compound with a skeleton carbon chain length of 11-17 by alkali catalytic condensation of furfural or 5-hydroxymethylfurfural and 1-hydroxy-2, 5-hexanedione, and then catalyzing a condensation product to perform hydrodeoxygenation by using a supported bifunctional catalyst to obtain a branched alkane crude product with a carbon chain length of 10-16 and a low-freezing-point characteristic;

3) preparing an oxygen-containing compound with a framework carbon chain length of 10-17 by alkali catalytic condensation of furfural or 5-hydroxymethylfurfural and cyclopentanone, and then catalyzing a condensation product to perform hydrodeoxygenation by using a supported bifunctional catalyst to obtain a crude product of cycloparaffin (five-membered ring) with a single branch chain or double branches, wherein the carbon chain length of the crude product is 10-17;

4) cyclopentanone is subjected to base-catalyzed self-condensation to prepare an oxygen-containing compound containing 2-3 five-membered ring structures, and then a supported bifunctional catalyst is used for catalyzing a condensation product to perform hydrodeoxygenation, so that a crude polycycloalkane product with a carbon chain length of 10-15 and high density is obtained;

5) preparing a phenol monomer from lignin components in the biomass raw material through directional depolymerization, and then carrying out hydrodeoxygenation under the action of a nickel-based catalyst to obtain an alkylcyclohexane crude product with a skeleton carbon chain length of 6-10, wherein the components have higher chemical heat sinks; 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in the phenol monomers are used as antioxidant component additives, so that the thermal oxidation stability of the aviation oil product can be improved;

6) the Pt-based multifunctional catalyst is adopted to carry out catalytic hydrofining on a mixture consisting of branched chain alkane crude products, single/double branched chain cycloalkane crude products, polycycloalkane crude products, alkyl cyclohexane crude products and antioxidant component additives, so as to obtain the special fuel with low freezing point, high density and high heat stability.

Performing steam stripping operation on the lignocellulose biomass raw material in the step 1) to convert hemicellulose components in the raw material into furfural; and then the water vapor pressure is increased, and the cellulose components in the lignocellulose biomass raw material are hydrolyzed and converted into 5-hydroxymethylfurfural.

The step adopts a kettle type reactor. The catalyst is a sulfuric acid-zinc sulfate catalyst system, the sulfuric acid-zinc sulfate catalyst is mixed with the biomass raw material and then is filled into a kettle type reactor, the mol ratio of sulfuric acid to zinc sulfate in the catalyst is preferably 1:1, and the dosage of the catalyst is 0.5-5% of the mass of the biomass raw material, preferably 3%; the pressure of stripping steam is 0.2-0.4MPa, and the stripping time is 0.5-5 h; subsequently, the steam pressure in the reactor is increased to 0.5-1.0MPa, preferably 0.6-0.8MPa, and the reaction time is 0.5-2h, so that the cellulose component is converted into 5-hydroxymethylfurfural.

The catalyst for catalyzing the condensation reaction of the furfural or 5-hydroxymethylfurfural and 1-hydroxy-2, 5-hexanedione in the step 2) is NaOH or KOH, the amount of the catalyst is 1-10% of the mass of the 1-hydroxy-2, 5-hexanedione, and the reaction temperature is room temperature; the catalyst for catalyzing the condensation reaction of furfural or 5-hydroxymethyl furfural and cyclopentanone in the step 3) is NaOH or KOH, the amount of the catalyst is 1-10% of the mass of the cyclopentanone, and the reaction temperature is 40-60 ℃; the catalyst for catalyzing the self-condensation of the cyclopentanone in the step 4) is NaOH or KOH, the dosage of the catalyst is 1-10% of the mass of the cyclopentanone, the reaction temperature is 60-100 ℃, and the condensation reaction adopts an intermittent reactor with stirring.

Specifically, the 1-hydroxy-2, 5-hexanedione in the step 2) is prepared by selectively hydrogenating 5-hydroxymethylfurfural, the reaction is carried out in a water phase, the used catalyst is Ru/C or Pd/C, the dosage of the catalyst is 0.5-5% of the mass of the 5-hydroxymethylfurfural, the reaction temperature is 80-120 ℃, and the hydrogen pressure is 0.1-1MPa, preferably 0.5-0.8 MPa; the cyclopentanone in the step 3) is prepared by selectively hydrogenating furfural, the reaction is carried out in a water phase, the catalyst is Raney Ni or a binary metal catalyst NiCu/SBA-15, the dosage of the catalyst is 5-20% of the mass of the furfural, the reaction temperature is 120-200 ℃, and the preferable temperature is 150-180 ℃.

The reaction conditions of the oxygen-containing compound in the steps 2), 3) and 4) for hydrodeoxygenation through the supported bifunctional catalyst are as follows: the dosage of the catalyst is 5-10% of the mass of the oxygen-containing compound, the temperature is between 200 and 400 ℃, the pressure is between 1 and 10MPa, the preferred temperature is 280 and 340 ℃, and the pressure is 3-5 MPa; the reaction can be carried out by using a high-pressure reaction kettle.

The supported bifunctional catalyst in the steps 2), 3) and 4) is prepared by an impregnation method of active metal and a solid acid carrier; wherein the metal active component comprises one or two of Pt, Pd, Ru and Ni, and the solid acid comprises active alumina, niobium hydroxide or zirconium phosphate; the loading amount of the metal Pt, Pd or Ru is 0.5-5 wt%, and the loading amount of the metal Ni is 5-30 wt%.

The step 5) of directionally depolymerizing the lignin to prepare the phenol monomer is to use zinc powder-zinc chloride as a catalyst, wherein the zinc powder: the mass ratio of zinc chloride is (1-5) to (1-2), methanol or ethanol is used as a solvent, and the reaction is carried out in a high-pressure reaction kettle in a hydrogen atmosphere; the depolymerization reaction temperature is between 240 ℃ and 320 ℃, and the dosage of the catalyst is 5-20% of the mass of the lignin raw material.

The product is purified and separated after the reaction is finished. Firstly, filtering a depolymerization product to remove catalyst zinc powder, lignin residues and coke particles; carrying out rotary evaporation on the liquid-phase product collected by filtration to remove the alcohol solvent; finally adding cyclohexane-water mixed liquid for extraction; and after standing, substances contained in the cyclohexane phase are phenolic monomers. 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in the phenolic monomers are used as antioxidant component additives.

The nickel-based catalyst used for preparing the alkylcyclohexane by the hydrodeoxygenation of the phenolic monomer in the step 5) is Ni/ZrO₂The catalyst is prepared by a method of co-crystallizing nickel nitrate and zirconium nitrate firstly and then roasting, wherein the content of Ni in the catalyst is 5-20 wt%, and the dosage of the catalyst is 5-20% of the mass of the phenol monomer; the reaction conditions are as follows: the temperature is between 200 ℃ and 400 ℃, the reaction pressure is between 1MPa and 10MPa, and the reaction time is between 2 hours and 24 hours; the preferred reaction conditions are: the temperature is between 250 ℃ and 320 ℃, the reaction pressure is between 3 MPa and 5MPa, the reaction time is between 8 hours and 12 hours, and the hydrodeoxygenation reaction is carried out in an autoclave. The antioxidant components 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol contained in the reaction raw material phenol monomer do not participate in the reaction due to steric effect.

Step 6) is to hydrofining the special aviation oil crude product mixture prepared in the steps 2), 3), 4) and 5). The composition distribution of the aviation fuel product is further adjusted through refining, and the special aviation fuel with high energy density, low freezing point, high heat sink and high heat stability is obtained.

The special aviation oil crude product comprises the following components: the branched alkane crude product accounts for 40-60 wt%, the crude product containing single/double branched chain cycloparaffin accounts for 10-20 wt%, the multicycloparaffin crude product accounts for 10-30 wt%, the alkylcyclohexane crude product accounts for 1-10 wt%, and the antioxidant component additive accounts for 0.01-1 wt%.

The Pt-based catalyst is Pt/SAPO-11, and the content of Pt in the catalyst is 0.1-2 wt%, preferably 0.6-1 wt%.

The hydrofining reaction is carried out in a fixed bed reactor. The conditions of the fixed bed reactor were: the temperature is 200-500 ℃, the reaction pressure is 1.0-10.0MPa, and the mass space velocity of reactants/catalyst is 0.1-5.0h^-1The molar ratio of hydrogen to substrate was 100-1000: 1. Preferred reaction conditions are: the temperature is between 340 ℃ and 400 ℃, the reaction pressure is between 4.0 and 6.0MPa, and the mass space velocity of reactants/catalyst is between 0.5 and 1.0h^-1The molar ratio of hydrogen to substrate was 600-800: 1.

The invention has the beneficial effects that:

the method successfully prepares the high-quality special aviation fuel oil, and realizes a novel conversion path for preparing the special aviation fuel oil with high energy density, low freezing point, high heat sink and high thermal stability by using the lignocellulose biomass as the raw material. Through the technical scheme provided by the invention, a technical system of the special fuel with directionally designed and synthesized fuel molecules and accurately controllable physical and chemical property indexes of products is constructed, so that the requirement of rapid development of high-performance aircrafts in China is met. After the technical achievements formed by the invention are applied in a large scale, the agricultural and forestry waste biomass resources with huge quantity in China are expected to be converted into fuel storage warehouses with inexhaustible values, which has important strategic significance for realizing source diversification of aerospace special aviation oil products, guaranteeing supply safety, promoting national defense construction and the like.

Detailed Description

The following examples are further illustrative of the present invention and are not intended to be limiting thereof, and all simple modifications of the invention which are within the spirit of the invention are intended to be within the scope of the invention as claimed.

The catalysts used in the following examples were prepared by techniques conventional in the art.

Examples 1 to 5: preparation of the platform Compounds

Mixing a sulfuric acid-zinc sulfate catalyst (the mol ratio of sulfuric acid to zinc sulfate is 1:1) with a biomass raw material (corn straws), filling the mixture into a kettle type reactor, introducing steam, converting hemicellulose in the raw material into a furfural platform compound through steam stripping operation, and taking the furfural platform compound away from the reactor; and then the water vapor pressure is increased, and the cellulose components in the lignocellulose biomass raw material are hydrolyzed and converted into 5-hydroxymethylfurfural. The specific parameters and the yields of the target products are shown in table 1.

TABLE 1

Examples 6 to 9: preparation of cyclopentanone

In a high-pressure reaction kettle, water is used as a solvent, furfural is subjected to selective hydrogenation rearrangement reaction under the action of Raney Ni (CAS: 7440-02-0) or NiCu/SBA-15 (the mass content of Ni is 10 percent, and an impregnation method is adopted to prepare a NiCu/SBA-15 catalyst with equal metal molar concentration) to be converted into cyclopentanone. The specific parameters and the yield of cyclopentanone, the target product, are shown in table 2.

TABLE 2

Examples 10 to 13: preparation of 1-hydroxy-2, 5-hexanedione

In a high-pressure reaction kettle, water is used as a solvent, and 5-hydroxymethylfurfural is selectively hydrogenated and converted into 1-hydroxy-2, 5-hexanedione under the action of a Pd/C or Ru/C catalyst with the metal loading of 5%. The specific parameters and the yield of the target product 1-hydroxy-2, 5-hexanedione are shown in Table 3.

TABLE 3

Examples 14 to 26: preparation of long carbon chain oxygen-containing compound by aldol condensation reaction

In a stirred batch reactor, furfural and 5-hydroxymethylfurfural respectively undergo a condensation reaction with 1-hydroxy-2, 5-hexanedione to prepare a long-carbon-chain oxygen-containing compound (C11-17), wherein a catalyst is NaOH or KOH, and specific reaction conditions and results are shown in examples 14-16 in Table 4; furfural and 5-hydroxymethyl furfural respectively undergo condensation reaction with cyclopentanone to prepare long-carbon-chain oxygen-containing compounds (C10-17), the catalyst is NaOH or KOH, and the specific reaction conditions and results are shown in examples 17-22 in Table 4; cyclopentanone is self-condensed under the catalysis of alkali to prepare the long carbon chain oxygen-containing compound containing 2-3 five-membered ring structures, and the specific reaction conditions and results are shown in examples 23-26 in Table 4.

TABLE 4

Examples 27 to 41: preparation of special aviation oil component crude product by hydrodeoxygenation

Carrying out hydrodeoxygenation reaction on the long-chain oxygen-containing compound in a high-pressure reaction kettle with a stirring device to realize preparation of the crude product of the aviation oil component. All examples in Table 5 were hydrodeoxygenated at 300 ℃ under a hydrogen pressure of 5MPa and a reaction duration of 8 h.

TABLE 5

Examples 42 to 48: preparation of phenol monomer by directional alcohol thermal depolymerization of lignin

Adding lignin raw material, catalyst (mixture of zinc powder and zinc chloride) and alcohol solvent into a high-pressure reaction kettle with a stirring device, replacing air, filling hydrogen to 2MPa, heating to a target temperature, and carrying out depolymerization reaction for 2 h. Filtering the depolymerized product after the reaction is finished, removing zinc powder, lignin residues and coke particles, then carrying out rotary evaporation on the liquid-phase product collected by filtering to remove an alcohol solvent, adding cyclohexane-water mixed liquid (the volume ratio is 2:1) to dissolve and extract the substances after the rotary evaporation, calculating the yield of a phenol monomer product by a subtraction method, and carrying out quantitative analysis on antioxidant component substances 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in the product. Specific parameters and experimental results are shown in table 6.

TABLE 6

Examples 49 to 54: preparation of crude product of alkyl cyclohexane by hydrogenation and deoxidation of phenol monomer

Hydrocarbon (crude alkylcyclohexane) was prepared by hydrodeoxygenation of the phenolic monomer prepared in example 43 in a high-pressure reactor using Ni/ZrO as catalyst₂The catalyst is prepared by a method of co-crystallizing nickel nitrate and zirconium nitrate firstly and then roasting, and the specific reaction conditions and the yield of a target product are shown in table 7. Detailed analysis was made on the product obtained in example 49, and it was found that the main component thereof was methylcyclohexane, dimethylcyclohexane, toluene, xylene, ethylcyclohexane, propylcyclohexane, ethylbenzene, trimethylbenzylnaphthalene, hydrogenated naphthalene, etc.; at the same time, antioxidant activity in the product was foundThe total content of the components 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol was 1.9%.

TABLE 7

Example 55: hydrorefining of crude product of special aviation oil

The crude product of cycloalkane containing a single branch or double branches obtained in example 30, the crude product of cycloalkane containing a single branch or double branches obtained in example 37, the crude product of polycycloalkane obtained in example 39, and the crude product of alkylcyclohexane obtained in example 49 (containing the antioxidant components 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in a total amount of 1.9%) were mixed in a mass ratio of 15:60:20:5 to form a crude product of specialty aviation oil, and the crude product was hydrorefined on a fixed bed using 1% Pt/SAPO-11 (i.e., 1 wt% of Pt in the catalyst) as a catalyst, wherein the fixed bed reactor conditions were as follows: the temperature is 360 ℃, the reaction pressure is 4.0MPa, and the mass space velocity of reactants/catalyst is 0.2h^-1The molar ratio of hydrogen to substrate was 300: 1. The density of the refined product was 0.82g/cm by analysis³The calorific value is 37.2MJ/L, and the freezing point is-67 ℃; and 2, 6-di-tert-butylphenol with the mass content of 0.12 percent was detected in the refined product.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.

Claims

1. A method for preparing a special fuel with low freezing point, high density and high thermal stability by using lignocellulose biomass is characterized by comprising the following steps:

3) preparing an oxygen-containing compound with a framework carbon chain length of 10-17 by alkali catalytic condensation of furfural or 5-hydroxymethylfurfural and cyclopentanone, and then catalyzing a condensation product to perform hydrodeoxygenation by using a supported bifunctional catalyst to obtain a crude cycloparaffin product with a carbon chain length of 10-17 and containing a single branch chain or a double branch chain;

5) preparing a phenol monomer from lignin components in the biomass raw material through directional depolymerization, and performing hydrodeoxygenation under the action of a nickel-based catalyst to obtain an alkylcyclohexane crude product with a skeleton carbon chain length of 6-10; 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in the phenolic monomers are taken as antioxidant component additives;

2. The preparation method according to claim 1, wherein step 1) is specifically: firstly, carrying out steam stripping on a lignocellulose biomass raw material to convert hemicellulose components in the lignocellulose biomass raw material into furfural and taking the furfural away from a reactor, wherein the used catalyst is a sulfuric acid-zinc sulfate catalyst system, the using amount of the catalyst is 0.5-5% of the mass of the biomass raw material, the steam pressure is 0.2-0.4MPa, and the steam stripping time is 0.5-5 h; and then raising the steam pressure in the reactor to 0.5-1.0MPa, maintaining for 0.5-2h, and converting the cellulose component into 5-hydroxymethylfurfural.

3. The preparation method according to claim 1, wherein the catalyst for catalyzing the condensation reaction of furfural, 5-hydroxymethylfurfural and 1-hydroxy-2, 5-hexanedione in the step 2) is NaOH or KOH, the amount of the catalyst is 1-10% of the mass of 1-hydroxy-2, 5-hexanedione, and the reaction temperature is room temperature; the catalyst for catalyzing condensation reaction of furfural, 5-hydroxymethyl furfural and cyclopentanone in the step 3) is NaOH or KOH, the amount of the catalyst is 1-10% of the mass of the cyclopentanone, and the reaction temperature is 40-60 ℃; the catalyst for catalyzing the self-condensation of cyclopentanone in the step 4) is NaOH or KOH, the dosage of the catalyst is 1-10% of the mass of the cyclopentanone, and the reaction temperature is 60-100 ℃.

4. The preparation method according to claim 1 or 3, wherein the 1-hydroxy-2, 5-hexanedione is prepared by selective hydrogenation of 5-hydroxymethylfurfural, the catalyst is Ru/C or Pd/C, the amount of the catalyst is 0.5-5% of the mass of the 5-hydroxymethylfurfural, the reaction temperature is 80-120 ℃, and the hydrogen pressure is 0.1-1 MPa; the cyclopentanone is prepared by selective hydrogenation of furfural, the catalyst is Raney Ni or a binary metal catalyst NiCu/SBA-15, the dosage of the catalyst is 5-20% of the mass of the furfural, and the reaction temperature is 120-200 ℃.

5. The method according to claim 1, wherein the oxygen-containing compound in the steps 2), 3) and 4) is hydrodeoxygenated under the following conditions: the dosage of the catalyst is 5-10% of the mass of the oxygen-containing compound, the reaction temperature is 200-400 ℃, and the reaction pressure is 1-10 MPa; the supported bifunctional catalyst is prepared from active metal and a solid acid carrier by an impregnation method; wherein the metal active component comprises one or two of Pt, Pd, Ru and Ni, and the solid acid comprises active alumina, niobium hydroxide or zirconium phosphate; the loading amount of the metal Pt, Pd or Ru is 0.5-5 wt%, and the loading amount of the metal Ni is 5-30 wt%.

6. The preparation method of claim 1, wherein the directional depolymerization of lignin to prepare the phenolic monomer in step 5) is carried out in a high-pressure reaction kettle in a hydrogen atmosphere by using zinc powder-zinc chloride as a catalyst, wherein the catalyst accounts for 5-20% of the mass of the lignin raw material and methanol or ethanol as a solvent; the depolymerization reaction temperature is between 240 ℃ and 320 ℃; and (3) purifying and separating the depolymerized product to obtain the phenol monomer containing 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol.

7. The preparation method according to claim 6, wherein the steps of purifying and separating the depolymerization product are as follows:

(1) filtering the depolymerization product to remove catalyst zinc powder, lignin residue and coke particles;

(2) carrying out rotary evaporation on the filtered liquid-phase product to remove the alcohol solvent;

(3) adding cyclohexane and water for dissolving and extracting; standing, and obtaining the substances contained in the cyclohexane phase, namely the phenolic monomers containing 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol.

8. The process according to claim 1, wherein the nickel-based catalyst used in the hydrodeoxygenation of the phenolic monomers to produce alkylcyclohexanes in step 5) is Ni/ZrO₂The Ni content in the catalyst is 5-20 wt%, the catalyst amount is 5-20% of the mass of the phenol monomer, the reaction temperature is 200-; 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol in the phenolic monomers do not participate in the reaction.

9. The method according to claim 1, wherein the mixture of step 6) contains branched alkane crude product 40-60 wt%, crude product containing mono/di-branched cycloalkane 10-20 wt%, crude product of polycycloalkane 10-30 wt%, crude product of alkylcyclohexane 1-10 wt%, and antioxidant component additive 0.01-1 wt%.

10. The method according to claim 1, wherein the Pt-based catalyst in step 6) is Pt/SAPO-11, and the content of Pt in the catalyst is 0.1-2 wt%; the hydrofining reaction adopts a fixed bed reactor, and the conditions of the fixed bed reactor are as follows: the temperature is 200-500 ℃, the reaction pressure is 1.0-10.0MPa, and the mass space velocity of reactants/catalyst is 0.1-5.0h^-1The molar ratio of hydrogen to the mixture was 100-1000: 1.