Method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products

Abstract

The present invention provides a method for preparing hydrocarbon fuels from light phenolic components in lignin depolymerization products, and belongs to the technical field of biomass liquid fuel preparation. The method for preparing hydrocarbon fuels from lignin depolymerization products of the present invention achieves efficient extraction of light phenolic components in lignin depolymerization products and efficient hydrodeoxygenation to prepare hydrocarbon fuels. The operation is simple and easy to implement. The extraction rate of light phenolic components can reach up to 92%, and the extracted solution basically does not contain medium-weight phenolic components and heavy phenolic components. The Ru / C catalyst treated with phosphotungstic acid proposed in the present invention combines the special physical and chemical properties of phosphotungstic acid and carbon carrier to obtain a strong interaction between the metal component and the acidic component. The catalyst has high hydrodeoxygenation reaction activity and good selectivity for hydrocarbon fuel products. In the catalytic activity evaluation, the conversion rate of light phenolic components is close to 100%, and the percentage of hydrocarbon fuel can reach up to 88.9%.

Description

Technical Field

[0001] The invention relates to the technical field of biomass liquid fuel preparation, and in particular to a method for preparing hydrocarbon fuel from light phenol components in lignin depolymerization products. Background Art

[0002] Biomass energy is widely distributed in nature and is renewable. Compared to petroleum resources, it can significantly reduce net carbon dioxide emissions and holds enormous potential for global energy supply. Furthermore, as a major agricultural country, my country's annual biomass production can reach 825 million tons, meeting the objective requirements for vigorously developing biomass energy. However, a large amount of biomass resources are currently underutilized. For example, straw accounts for approximately 52% of total biomass resources, but only 40% is recycled, with the remainder directly burned in the open air. This not only hinders the effective utilization of biomass resources but also seriously harms the natural environment. Biomass is considered a carbon-neutral resource, and large-scale recycling and utilization can help achieve carbon reduction goals. The production of biomass into liquid fuels and chemicals can also realize its high-value applications. As a key component of biomass resources, lignocellulosic biomass (including hardwoods, softwoods, and grasses) represents the most promising feedstock for the sustainable production of biofuels and bio-derived chemicals. Lignocellulose is a complex and valuable polymer composed primarily of cellulose, hemicellulose, and lignin. Cellulose and hemicellulose have relatively simple structures and have been partially utilized on a large scale in industry to produce important chemicals and fuels such as 5-hydroxymethylfurfural and fuel ethanol. However, lignin has a complex structure and is very stable, making its conversion and utilization difficult. Industrially, it is generally discarded or burned as a byproduct, resulting in significant waste. Lignin is a complex three-dimensional polymer composed of three phenylpropane structural monomers (p-hydroxyphenol H units, guaiacyl G units, and syringyl S units) randomly bonded through CO and CC bonds. It is the only renewable resource in nature that can directly provide benzene rings. The high carbon content and high calorific value of the benzene ring structure make lignin have great potential for the production of high-quality liquid fuels.

[0003] Lignin has a huge relative molecular weight. To be converted into high-quality liquid fuel, it must first be depolymerized into compounds with lower relative molecular weights. There are two main methods for lignin depolymerization: one is chemical and the other is biological. Biological depolymerization uses enzymes and other additives to break the connections between lignin molecules. It is environmentally friendly and has high selectivity for the target product, but the reaction time is long and it is easily deactivated, making it difficult to be widely used in industrial production. In contrast, the chemical method has a fast reaction rate and relatively low environmental requirements, which has great advantages for industrial production. Among them, the liquid-phase catalytic depolymerization method in the chemical method, due to the participation of a liquid-phase solvent, can achieve efficient depolymerization of lignin under relatively mild conditions, obtaining a high yield of light phenolic components. However, the lignin depolymerization product obtained by the liquid-phase catalytic depolymerization method of lignin is dissolved in the solvent. If further modification is required, it needs to be extracted from the solvent. Furthermore, the lignin depolymerization products dissolved in the solvent, in addition to the light phenolic components, also include medium and heavy phenolic components. These two components are relatively complex in structure, have unstable physicochemical properties, are difficult to utilize, and can mix with the light phenolic components, negatively impacting their extraction and utilization. Patent (CN106753549B) proposes a method for extracting light phenolic components from bio-oil using rotary distillation combined with ethyl acetate extraction. However, this process is energy-intensive and complex, inevitably leading to the loss of light phenolic components.

[0004] The light phenolic components in the lignin depolymerization products contain a certain amount of oxygen and unsaturated functional groups. If they are to be used as high-quality liquid fuels, they need to be further improved, and hydrodeoxygenation is the most common method of quality improvement. There are many types of catalysts for hydrodeoxygenation. The earlier research is the catalyst with metal sulfide as the active phase, including molybdenum sulfide, cobalt sulfide, etc. This type of catalyst generally requires the continuous addition of hydrogen sulfide gas to the reaction system to maintain the sulfidation state of the metal. The operation is complicated, and the introduction of sulfur will also contaminate the prepared liquid fuel. Supported transition metal catalysts also have good hydrodeoxygenation effects. Among them, nickel-based catalysts are widely used and can achieve complete hydrodeoxygenation of oxygen-containing compounds under relatively mild conditions. Precious metals have higher catalytic activity for hydrogen adsorption and dissociation than transition metals, and have better hydrodeoxygenation reaction effects. Patent (CN102676201A) proposes a variety of supported metal / solid acid catalysts for the hydrodeoxygenation of bio-oil. However, due to the low activity of both the metal component and the acidic component in the catalyst, and the weak interaction between the metal component and the acidic component, the hydrodeoxygenation reaction requires relatively high temperatures (greater than 250°C) to achieve good results. Patent (CN109971505A) proposes using a Ru / TiO2 catalyst with highly dispersed Ru metal to promote the hydrodeoxygenation reaction from the perspective of the metal component. However, in addition to the metal component, the acidic component also plays an important role in the hydrodeoxygenation catalyst, and the removal of oxygen is highly dependent on the catalytic action of the acidic component. Coupling the metal component and the acidic component to prepare a bifunctional catalyst can improve the hydrodeoxygenation effect of the hydrodeoxygenation catalyst to a certain extent. However, existing bifunctional catalysts are mainly supported, and the interaction between the metal component and the acidic component is weak, making it difficult to fully utilize the synergistic effect of the metal component and the acidic component.

[0005] Light phenolic components in lignin depolymerization products can be hydrodeoxygenated to produce hydrocarbons with carbon numbers ranging from C6 to C10. These hydrocarbons have vapor pressures and carbon number distributions similar to gasoline components and possess a high octane rating, making them ideal components for transportation fuels. The lignin depolymerization products obtained by liquid-phase catalytic depolymerization contain not only light phenolic components but also medium and heavy phenolic components. These medium and heavy phenolic components are susceptible to polycondensation during the hydrodeoxygenation process, leading to carbon accumulation on the catalyst surface and deactivation, thus negatively impacting the hydrodeoxygenation reaction. Extracting the light phenolic components from the complex lignin depolymerization products before hydrodeoxygenation can not only improve the quality of the liquid fuel but also prevent catalyst deactivation caused by polycondensation of the complex components of the lignin depolymerization products. Patent (CN109971505A) uses an organic solvent extraction method such as n-octane to extract light phenolic components. However, the medium-weight phenolic components and the light-weight phenolic components have some similar physical and chemical properties, making them difficult to completely separate. In addition, the heavy phenolic components will also be more or less mixed with the light-weight phenolic components, which will have a negative impact on the subsequent hydrodeoxygenation and quality improvement.

[0006] Therefore, it is of great significance to completely and efficiently separate light phenolic components from lignin depolymerization products for subsequent efficient hydrodeoxygenation. Summary of the Invention

[0007] The present invention provides a method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products, the purpose of which is to solve the above-mentioned problems existing in the background technology.

[0008] In order to achieve the above object, an embodiment of the present invention provides a method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products, comprising the following steps:

[0009] S1: adding water to the lignin depolymerization product, stirring and mixing, then adding n-octane, ultrasonicating, standing and separating the n-octane, and obtaining a solution containing light phenolic components in the lignin depolymerization product;

[0010] S2: placing the solution containing the light phenolic components in the lignin depolymerization product into a high-temperature and high-pressure reactor, adding a Ru / C catalyst treated with phosphotungstic acid to carry out a hydrodeoxygenation reaction to obtain a hydrocarbon fuel;

[0011] The specific process of treating the Ru / C catalyst with phosphotungstic acid is as follows: mixing the Ru / C catalyst with phosphotungstic acid, heating while stirring until the phosphotungstic acid melts, cooling, transferring to a tube furnace, performing a calcination reduction reaction, and cooling to obtain the Ru / C catalyst treated with phosphotungstic acid.

[0012] Furthermore, the Ru / C catalyst is 0.1g 5wt% and the phosphotungstic acid is 10-30wt%.

[0013] Furthermore, the calcination reduction reaction conditions are: in a hydrogen atmosphere, a flow rate of 10 mL / min, and calcination reduction at 500° C. for 4 h.

[0014] Furthermore, the hydrocarbon fuel component includes one or more of cycloalkanes, alkylcycloalkanes, benzene and alkylbenzenes.

[0015] Furthermore, the ultrasonication time in step S1 is 5 to 10 minutes.

[0016] Furthermore, the reaction conditions in step S2 are: temperature 220° C. to 240° C., reaction time 4 h, under hydrogen atmosphere, pressure 1 MPa.

[0017] Furthermore, the volume ratio of the lignin depolymerization product to water is 4:4 to 4:8; the volume ratio of the lignin depolymerization product to n-octane is 4:4 to 4:8.

[0018] Furthermore, the lignin raw material is added to an ethanol solution, and then a NiCo / C catalyst is added. After mixing evenly, the mixture is placed in a high-temperature and high-pressure reactor for reaction, and filtered to obtain the lignin depolymerization product.

[0019] Furthermore, the lignin raw material includes at least one of industrial lignin, organosoluble lignin, alkali lignin, and sulfonate lignin.

[0020] Furthermore, the reaction conditions are: pressure 3 MPa, heating to 260° C. in a hydrogen atmosphere, and reaction time is 4 h.

[0021] The present invention uses the following method to evaluate catalytic performance: 20 mL of an n-octane solution containing extracted light phenolic components and 0.1 g of a Ru / C catalyst treated with phosphotungstic acid were added to a 50 mL 316L high-temperature, high-pressure reactor. The reaction was carried out at 240°C under a 1 MPa hydrogen atmosphere for 4 hours. Testing showed that the conversion of light phenolic components approached 100%, and the selectivity for hydrocarbon fuels reached a maximum of 83.9%.

[0022] The above solution of the present invention has the following beneficial effects:

[0023] (1) The present invention provides a method for preparing hydrocarbon fuels from lignin depolymerization products, which achieves efficient extraction of light phenolic components in lignin depolymerization products and efficient hydrodeoxygenation to prepare hydrocarbon fuels;

[0024] (2) The present invention proposes a highly efficient extraction of light phenolic components from the lignin depolymerization product, which is simple to operate and easy to implement. The extraction rate of light phenolic components can reach up to 92%, and the extracted solution is essentially free of medium-weight phenolic components and heavy phenolic components.

[0025] (3) The Ru / C catalyst treated with phosphotungstic acid (PTTA) proposed in this invention combines the unique physicochemical properties of PTTA and a carbon support, resulting in a strong interaction between the metal and acidic components. The catalyst exhibits high hydrodeoxygenation activity and good selectivity for hydrocarbon fuel products. In catalytic activity evaluations, the conversion rate of light phenolic components approached 100%, and the percentage of hydrocarbon fuel reached as high as 88.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 1 is a transmission electron microscope photograph of the Ru / C catalyst treated with phosphotungstic acid obtained in Example 1 of the present invention and its element distribution map;

[0028] Figure 2 This is the GC-MS spectrum of the light phenolic components extracted in Example 5 of the present invention before and after hydrodeoxygenation, wherein: Figure 2 a is before hydrodeoxygenation, Figure 2 b after hydrodeoxygenation. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0030] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0032] In view of the existing problems, the present invention provides a method for preparing hydrocarbon fuels from light phenolic components in lignin depolymerization products.

[0033] The preparation process of the lignin depolymerization product in the following example is as follows: a certain lignin raw material (including industrial lignin, organic soluble lignin, alkali lignin, sulfonate lignin, etc.) is added to an ethanol solution, and then a NiCo / C catalyst is added. After mixing evenly, it is placed in a high-temperature and high-pressure reactor, filled with 3MPa hydrogen, heated to 260°C, and reacted for 4h (for reaction conditions, see reference material Fuel, 2023, 333, 126357.). After the reaction is completed, the reaction mixture is filtered to collect the liquid lignin depolymerization product. The lignin depolymerization product is mainly composed of light phenolic components, medium phenolic components, and heavy phenolic components. Among them, the medium phenolic components and heavy phenolic components have complex structures and are difficult to further convert into hydrocarbon fuels.

[0034] Example 1

[0035] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 4:4. The mixture was stirred for 5 minutes to fully mix. Then, n-octane was added, and the volume ratio of n-octane to raw material was 4:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0036] (2) Take 20 mL of the n-octane solution of the light phenol component obtained in step (1) and put it into a 50 mL 316 L high temperature and high pressure reactor, add the Ru / C catalyst treated with phosphotungstic acid (transmission electron microscope photos and element distribution map are shown in Figure 1 ) was subjected to a hydrodeoxygenation reaction with a phosphotungstic acid loading of 20 wt %, a catalyst dosage of 0.1 g, a reaction temperature of 220° C., a reaction time of 4 h, and a hydrogen pressure of 1 MPa to obtain a hydrocarbon liquid fuel.

[0037] Example 2

[0038] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 4:4. The mixture was stirred for 5 minutes to be fully mixed. Then, n-octane was added, and the volume ratio of n-octane to raw material was 6:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0039] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The phosphotungstic acid loading of the catalyst was 20 wt %, the amount of the catalyst was 0.1 g, the reaction temperature was 220 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0040] Example 3

[0041] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 4:4. The mixture was stirred for 5 minutes to be fully mixed. Then, n-octane was added, and the volume ratio of n-octane to raw material was 8:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0042] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The phosphotungstic acid loading of the catalyst was 20 wt %, the amount of the catalyst was 0.1 g, the reaction temperature was 220 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0043] Example 4

[0044] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 6:4. The mixture was stirred for 5 minutes to be fully mixed. Then, n-octane was added, and the volume ratio of n-octane to raw material was 8:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0045] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The phosphotungstic acid loading of the catalyst was 20 wt %, the amount of the catalyst was 0.1 g, the reaction temperature was 220 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0046] Example 5

[0047] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 8:4. The mixture was stirred for 5 minutes to be fully mixed. Then, n-octane was added, and the volume ratio of n-octane to raw material was 8:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0048] (2) Take 20 mL of the light phenolic component obtained in step (1) (see Figure 2 , its GC-MS spectra before and after hydrodeoxygenation, among which, Figure 2 a is before hydrodeoxygenation, Figure 2b (after hydrodeoxygenation) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The catalyst loading amount of phosphotungstic acid was 20 wt %, the catalyst dosage was 0.1 g, the reaction temperature was 220° C., the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0049] Example 6

[0050] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 8:4. The mixture was stirred for 5 minutes to fully mix. Then, n-octane was added, and the volume ratio of n-octane to raw material was 8:4. Ultrasonic treatment was performed for 5 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0051] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The catalyst phosphotungstic acid loading was 30 wt %, the catalyst dosage was 0.1 g, the reaction temperature was 220 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0052] Example 7

[0053] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 8:4. The mixture was stirred for 5 minutes to fully mix. Then, n-octane was added, and the volume ratio of n-octane to raw material was 8:4. Ultrasonic treatment was performed for 5 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0054] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The catalyst phosphotungstic acid loading was 30 wt %, the catalyst dosage was 0.1 g, the reaction temperature was 240 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0055] Comparative Example 1

[0056] (1) Using the lignin depolymerization product as raw material, n-octane was added, and the volume ratio of n-octane to raw material was 4:4, and ultrasonic treatment was performed for 10 minutes. Finally, the product was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution in which light phenolic components were extracted;

[0057] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL 316 L high-temperature and high-pressure reactor, and a Ru / C catalyst treated with phosphotungstic acid was added to carry out a hydrodeoxygenation reaction. The phosphotungstic acid loading of the catalyst was 20 wt %, the amount of the catalyst was 0.1 g, the reaction temperature was 220 ° C, the reaction time was 4 h, and the hydrogen pressure was 1 MPa to obtain a hydrocarbon liquid fuel.

[0058] Comparative Example 2

[0059] (1) Using the lignin depolymerization product as raw material, a certain amount of water was added, and the volume ratio of water to raw material was 4:4. The mixture was stirred for 5 minutes to fully mix. Then, n-octane was added, and the volume ratio of n-octane to raw material was 4:4. Ultrasonic treatment was performed for 10 minutes. Finally, the mixture was transferred to a separatory funnel and allowed to stand for separation of n-octane to obtain an n-octane solution with light phenolic components extracted.

[0060] (2) 20 mL of the n-octane solution of the light phenol component obtained in step (1) was placed in a 50 mL / 316 L high-temperature and high-pressure reactor, 0.05 g of Ru / C catalyst and 0.05 g of Al2O3 solid acid were added, and a hydrodeoxygenation reaction was carried out at a reaction temperature of 220°C, a reaction time of 4 h, and a hydrogen pressure of 1 MPa to obtain a hydrocarbon liquid fuel.

[0061] Example 8

[0062] GC-MS was used to characterize the amounts of light phenolic components before and after extraction with n-octane solutions in Comparative Examples 1 and 2 and Examples 1 to 7, where the light phenolic components were extracted in step (1). Before extraction, the light phenolic components were in the lignin depolymerization product, while after extraction, the light phenolic components were in n-octane. The extraction yield was calculated by the ratio of the sum of the peak areas of the individual light phenolic components.

[0063] As shown in Table 1, the extraction rate of the light phenolic components in Examples 1 to 7 can reach up to 92%. From the comparison between Comparative Example 1 and Example 1, it can be seen that the addition of water promotes the extraction of the light phenolic components, with the extraction rate increasing from 62% to 69%.

[0064] Table 1 Extraction rate of light phenolic components in lignin depolymerization products

[0065]

[0066] Example 9

[0067] GC-MS was used to characterize the amount of hydrocarbon fuel before and after hydrodeoxygenation of the n-octane solution from which the light phenolic components were extracted in step (1) of Comparative Examples 1 and 2 and Examples 1 to 7. The hydrocarbon fuel components include one or more of cycloalkanes, alkylcycloalkanes, benzene, and alkylbenzenes. The percentage of the peak area of ​​each hydrocarbon fuel compound to the total peak area of ​​all compounds in the chromatogram represents the percentage content of the hydrocarbon fuel.

[0068] As shown in Table 2, the percentage of hydrocarbon fuel obtained after the hydrodeoxygenation reaction of the n-octane solutions of the light phenolic components obtained in Step 1 of Examples 1 to 7 of the present invention increased, with the percentage of hydrocarbon fuel reaching a maximum of 88.9%. Comparing the results of Comparative Example 1 and Example 1, the percentage of hydrocarbon fuel obtained after the hydrodeoxygenation reaction of the light phenolic components extracted with water was 9.4% higher than that obtained without water. This is primarily because the light phenolic components extracted with water are essentially free of medium-weight and heavy phenolic components, which do not negatively affect the hydrodeoxygenation reaction, demonstrating the advanced nature and innovation of the present invention. From the comparison results of Comparative Example 2 and Example 1, the hydrodeoxygenation effect of the Ru / C catalyst treated with phosphotungstic acid proposed in the present invention is also better than that of the conventional Ru / C coupled Al2O3 catalyst. This is mainly because the Ru / C catalyst treated with phosphotungstic acid proposed in the present invention combines the special physical and chemical properties of phosphotungstic acid and carbon support, obtains a strong interaction between the metal component and the acidic component, and greatly improves the hydrodeoxygenation reaction activity, which is incomparable to conventional bifunctional catalysts and also reflects the advanced nature and innovation of the present invention.

[0069] Table 2 shows the percentage of hydrocarbon fuels before and after hydrodeoxygenation

[0070]

[0071] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products, characterized in that: The steps include: S1: adding water to a lignin depolymerization product, stirring and mixing, and then adding n-octane, wherein the volume ratio of the lignin depolymerization product to water is 4:4 to 4:8; the volume ratio of the lignin depolymerization product to n-octane is 4:4 to 4:8; ultrasonicating, standing and stratifying to separate the n-octane, and obtaining a solution containing light phenolic components in the lignin depolymerization product; the lignin raw material comprises at least one of organosoluble lignin, alkali lignin, and sulfonate lignin; S2: placing the solution containing the light phenolic components in the lignin depolymerization product into a high-temperature and high-pressure reactor, adding a Ru / C catalyst treated with phosphotungstic acid to carry out a hydrodeoxygenation reaction at a reaction temperature of 240° C. to obtain a hydrocarbon fuel; The specific process of treating the Ru / C catalyst with phosphotungstic acid is as follows: mixing the Ru / C catalyst with phosphotungstic acid, heating with stirring until the phosphotungstic acid melts, cooling, transferring the mixture to a tube furnace, performing a calcination reduction reaction, and cooling to obtain the Ru / C catalyst treated with phosphotungstic acid; the calcination reduction reaction conditions are: in a hydrogen atmosphere, at a flow rate of 10 mL / min, and calcining and reducing at 500°C for 4 hours.

2. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 1, characterized in that: The phosphotungstic acid loading is 10-30 wt%.

3. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 1, characterized in that: The hydrocarbon fuel component includes one or more of cycloalkanes, benzene and alkylbenzenes.

4. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 1, characterized in that: The ultrasonic time in step S1 is 5 to 10 minutes.

5. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 1, characterized in that: The reaction conditions in step S2 are as follows: reaction time 4 h, hydrogen atmosphere, and pressure 1 MPa.

6. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 1, characterized in that: The lignin raw material is added to an ethanol solution, and then a NiCo / C catalyst is added. After mixing evenly, the mixture is placed in a high-temperature and high-pressure reactor for reaction, and filtered to obtain the lignin depolymerization product.

7. The method for preparing hydrocarbon fuel from light phenolic components in lignin depolymerization products according to claim 6, characterized in that: The reaction conditions for obtaining the lignin depolymerization product are: pressure 3 MPa, heating to 260° C. in a hydrogen atmosphere, and reaction time 4 h.

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