A method for directional regulation of bio-oil hydrodeoxygenation to produce biodiesel

Abstract

The application discloses a method for preparing biodiesel by directional regulation of hydrogenation deoxygenation of biological oil, and belongs to the technical field of biodiesel preparation, and comprises the following steps: biological oil is dissolved in a solvent, mixed with hydrogen, and injected into a fixed bed reactor; a Ni catalyst supported by atom-substituted zirconia is used for hydrogenation deoxygenation reaction; by changing the element doped in the carrier of the Ni catalyst supported by atom-substituted zirconia, the biological oil is controlled to generate alkanes with corresponding carbon numbers or alkanes with one less carbon atom, so that the biodiesel is obtained; the chemical formula of the Ni catalyst supported by atom-substituted zirconia is Ni / xMZrO2, x is the mole percentage of M in the carrier, and M is one or both of Ce and Ti. The carrier of the Ni / ZrO2 catalyst is functionally treated by using the additives Ce and Ti, the chemical properties of the catalyst are regulated, the controllable regulation of the hydrogenation activity and product selectivity of the biological oil is realized, the selectivity of the target alkane component is improved, and high-quality biodiesel is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biodiesel preparation, and in particular to a method for preparing biodiesel by directional regulation of biodiesel hydrogenation deoxygenation. BACKGROUND

[0002] In recent years, biodiesel has replaced traditional fossil fuels to provide energy for various industries due to its advantages of being renewable, clean, and abundant in reserves. However, biodiesel contains a large number of oxygen atoms in its molecular composition, which has the disadvantages of poor stability, low heat value, and high viscosity when used directly as fuel. Therefore, it is necessary to remove oxygen atoms by hydrogenation deoxygenation of biodiesel to improve the quality of the oil product and obtain high-calorie and clean biodiesel. Therefore, finding an efficient and stable catalyst is the key to the development of biodiesel for preparing clean energy.

[0003] Currently, the commonly used biodiesel hydrogenation deoxygenation catalysts are mainly divided into noble metal catalysts and metal sulfide catalysts. However, the high price of noble metal catalysts limits its large-scale application, and the loss of sulfur during the reaction process leads to a decrease in activity and pollution of metal sulfide. The preparation method of a multi-metal sulfide hydrogenation deoxygenation catalyst is disclosed in the invention patent with the publication number CN117797832A, and is applied to the hydrogenation of waste oil to prepare biodiesel. Although this method shows high deoxygenation rate and alkane yield, the preparation process of the catalyst is relatively complex, and the use of sulfur powder in situ sulfuration can cause product pollution. Therefore, the development and application of clean non-noble metal-based catalysts have attracted much attention.

[0004] There are mainly two ways for the hydrogenation deoxygenation of biodiesel. One is the direct hydrogenation deoxygenation path (HDO), which removes oxygen atoms in the form of H2O and generates alkane with the corresponding number of carbon atoms. The direct hydrogenation deoxygenation process does not remove carbon, and has higher atomic economic efficiency, but inevitably generates water, which can easily damage the structure of the catalyst and cause irreversible decline in catalytic activity. Therefore, the water resistance of the catalyst will be higher. The other is the hydrogenation decarboxylation / decarbonylation path (DCO), which removes oxygen atoms in the form of CO / CO2 to generate alkane with one less carbon atom. Although hydrogenation decarboxylation / decarbonylation only produces a small amount of water, or even no water, CO2 / CO is generated during the reaction process, causing a certain loss of carbon.

[0005] The invention patent with publication number CN111715229A discloses a method for preparing biofuel by catalyzing methyl laurate deoxygenation with a sulfur-free nickel-based catalyst Ni / CeO2-TiO2. Under the conditions of a methyl laurate and catalyst mass ratio of 10, a reaction temperature of 300 DEG C, a hydrogen pressure of 2.5 MPa, and a reaction time of 4 h, a biofuel product with a mass yield of 96% can be obtained, and the mass percentage of n-undecane in the product is 98%. In this process, the product obtained by using the catalyst is mainly n-undecane, but this does not meet the requirements of atomic economic benefits. How to control the directional selectivity of bio-oil catalytic direct hydrogenation deoxygenation, hydrogenation decarboxylation / decarbonylation according to the design and modification of the catalyst is a problem to be solved.

[0006] In summary, there is still a lot of research space for the existing research on the preparation of biodiesel by hydrogenation deoxygenation of bio-oil. In combination with the current research status, the present patent proposes a method for directional regulation of bio-oil hydrogenation deoxygenation for preparing biodiesel. SUMMARY

[0007] The purpose of the present application is to provide a method for directional regulation of bio-oil hydrogenation deoxygenation for preparing biodiesel, in order to solve the problems in the background art.

[0008] To achieve the above-mentioned purpose, the present application provides a method for directional regulation of bio-oil hydrogenation deoxygenation for preparing biodiesel, comprising the following steps:

[0009] The bio-oil is dissolved in a solvent to obtain a mixed solution with a mass concentration of 1.0-20%, and the mixed solution is mixed with hydrogen and then injected into a fixed bed reactor. A Ni catalyst supported on an atom-substituted zirconia is used for hydrogenation deoxygenation reaction. By changing the coordination structure of the carrier and the heteroatom in the Ni catalyst supported on the atom-substituted zirconia, the directional generation of alkanes with the same carbon number or alkanes with one less carbon atom from bio-oil is controlled, and biodiesel is obtained.

[0010] The chemical formula of the Ni catalyst supported on the atom-substituted zirconia is Ni / xMZrO2, x is the mole percentage of M in the carrier, and the value is 1-20%; M is one or both of Ce and Ti, and the loading amount of Ni is 5-50 wt.%.

[0011] The Ni catalyst supported on the atom-substituted zirconia is used as a catalyst for the preparation of biodiesel by hydrogenation deoxygenation of bio-oil. The heteroatom M replaces the original Zr atom in the ZrO2 crystal structure to form a M-O-Zr coordination structure, which precisely adjusts the electronic state and chemical properties of the ZrO2 carrier, thereby controlling the directional generation of alkanes with the same carbon number or alkanes with one less carbon atom from bio-oil.

[0012] Preferably, the preparation steps of the Ni catalyst supported on the atom-substituted zirconia are as follows:

[0013] 1) one or two of zirconium salt, cerium salt or titanium salt are mixed and dissolved in deionized water to obtain a metal precursor salt solution, then urea is added and stirred sufficiently to dissolve to obtain a mixed solution; the mixed solution is heated in a reaction kettle, filtered to obtain a precipitate, washed and dried, and then calcined in an O2 / Ar mixed atmosphere to obtain an atomic substitution type zirconia carrier;

[0014] 2) the obtained atomic substitution type zirconia carrier and a nickel salt are added to deionized water, stirred uniformly, rotary evaporated, dried, and then calcined in an O2 / Ar mixed atmosphere to obtain an atomic substitution type zirconia supported Ni-based catalyst.

[0015] Preferably, in the specific preparation step 1) of the atomic substitution type zirconia carrier, the molar ratio of urea to the metal precursor salt solution is 10:1, the heating temperature in the reaction kettle is 120-180℃, the heating time is 10-20h, the calcination temperature is 500-650℃, and the calcination time is 3-5h.

[0016] Preferably, in the preparation step 2) of the atomic substitution type zirconia supported Ni catalyst, the stirring time is 8-12h, the calcination temperature is 340-450℃, and the calcination time is 3-5h.

[0017] Preferably, the biological oil is one or more of palm oil, soybean oil, and rapeseed oil.

[0018] Preferably, the solvent is one or more of n-decane, cyclohexane, and n-heptane.

[0019] Preferably, before the hydrodeoxygenation reaction, the atomic substitution type zirconia supported Ni catalyst is in-situ reduced in a fixed bed reactor for 1.5-2.5h at a reduction temperature of 300-400℃.

[0020] Preferably, during the hydrodeoxygenation reaction, the concentration of the biological oil is 1.0-20wt.%, the temperature is 160-300℃, the hydrogen pressure is 0.2-4MPa, the mass space velocity is 0.2-4.8h-1, and the ratio of hydrogen to biological oil is 200-800:1. -1

[0021] Therefore, the method for directional regulation of the preparation of biodiesel from biological oil through hydrodeoxygenation has the following beneficial effects:

[0022] ​(1) The application realizes controllable adjustment of the hydrogenation activity and product selectivity of biological oil, improves the selectivity of target alkane components, and obtains high-quality biodiesel, by using the auxiliary agents Ce and Ti to functionalize the carrier of the Ni / ZrO2 catalyst, regulating the chemical properties of the catalyst, and providing a method for the design of a catalyst for selective conversion in a biological oil hydrogenation and deoxidization system, especially for product selection, with many advantages such as cleanliness, high reserves, and low cost.

[0023] (2) In the application, Ce atoms replace Zr atoms and are inserted into ZrO2 to form Ce-O-Zr bonds, because the electronegativity of Ce (1.12) is lower than that of Zr (1.4), the electrons in the Ce-O-Zr bond are attracted by Zr, so that more electrons are enriched around Zr, and according to the acid-base proton theory, the enrichment of electrons on the surface of the catalyst can form Lewis acid sites, which are directly beneficial to the adsorption of oxygen-containing groups in biological oil; on the other hand, the electronic effect of the Zr-O-Ni interface effectively improves the hydrogenation and C-C bond cleavage capacity of the catalyst, so that it has higher activity and decarboxylation selectivity.

[0024] The Ti atoms replace Zr atoms and are inserted into ZrO2 to form Ti-O-Zr bonds, the difference is that the electronegativity of Ti (1.54) is higher than that of Zr (1.4), so that Zr is in an electron-deficient state around the Zr-O-Zr bond, which directly increases the content of hydroxyl groups on the surface of the ZrO2 carrier, and the hydroxyl groups on the surface of the catalyst can act as Bronsted acid sites to improve the C-O / C=O cleavage capacity of the catalyst, and obtain higher direct hydrogenation and deoxidization selectivity.

[0025] The ternary atom-substituted type carrier loaded with Ni catalyst composed of Ce, Ti and Zr can realize the adjustment of the electronic state and acidity of the ZrO2 carrier by changing the ratio of Ce and Ti, and then realize the directional regulation of the hydrogenation activity and target product.

[0026] The technical solutions of the application will be further described in detail below through the drawings and examples. DETAILED DESCRIPTION

[0027] Figure 1 X-ray diffraction patterns of the catalyst Ni / ZrO2 of the comparative example 1, the catalyst Ni / 5CeZrO2 of the example 3 and the catalyst Ni / 10TiZrO2 of the example 7 in the application;

[0028] Figure 2 TEM characterization diagrams of the catalyst Ni / ZrO2 of the comparative example 1, the catalyst Ni / 5CeZrO2 of the example 3 and the catalyst Ni / 10TiZrO2 of the example 7 in the application, wherein a is Ni / 10TiZrO2, b is Ni / ZrO2, and c is Ni / 5CeZrO2;

[0029] Figure 3 The above are XPS Zr 3d spectra of the catalyst Ni / ZrO2 in Comparative Example 1, the catalyst Ni / 5CeZrO2 in Example 3, and the catalyst Ni / 10TiZrO2 in Example 7 in this invention. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0032] Example 1

[0033] The steps for preparing the Ni / 1CeZrO2 catalyst are as follows:

[0034] 1) Mix ZrO(NO3)2·xH2O and Ce(NO3)3·6H2O and dissolve them in deionized water. The amount of Ce(NO3)3·6H2O added is 1 mol.%; to obtain a metal precursor salt solution with a concentration of 0.4 mol / L; add 16.817 g of urea to the metal precursor salt solution and stir thoroughly until completely dissolved to obtain a mixed solution.

[0035] The resulting mixed solution was then transferred to a 100 mL reactor and heated at 150 °C for 12 h. After filtration and washing, the powder sample was dried at 100 °C overnight and then calcined at 600 °C in an O2 / Ar mixed atmosphere for 4 h to obtain the 1CeZrO2 support.

[0036] 2) Add 1g of 1CeZrO2 support and 1.23g of Ni(NO3)2·6H2O to a certain amount of deionized water, stir for 10h, then evaporate by rotary evaporation, dry at 100℃ overnight, and calcine at 400℃ in an O2 / Ar mixed atmosphere for 4h to obtain Ni / 1CeZrO2 catalyst.

[0037] Example 2

[0038] The Ni / 3CeZrO2 catalyst was prepared using the same steps as in Example 1, except that the amount of Ce added was changed to 3 mol.

[0039] Example 3

[0040] The Ni / 5CeZrO2 catalyst was prepared using the same steps as in Example 1, except that the amount of Ce added was changed to 5 mol.

[0041] Example 4

[0042] A Ni / 10CeZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that the amount of Ce added was changed to 10 mol.%.

[0043] Example 5

[0044] A Ni / 1TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that Ce(NO3)3-6H2O was replaced by Ti(SO4)2.

[0045] Example 6

[0046] A Ni / 5TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that the amount of Ti added was changed to 5 mol.%.

[0047] Example 7

[0048] A Ni / 10TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that the amount of Ti added was changed to 10 mol.%.

[0049] Example 8

[0050] A Ni / 15TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that the amount of Ti added was changed to 15 mol.%.

[0051] Example 9

[0052] A Ni / 3Ce7TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that ZrO(NO3)2-xH2O was mixed with 3 mol.% of Ce(NO3)3-6H2O and 7 mol.% of Ti(SO4)2 in deionized water.

[0053] Example 10

[0054] A Ni / 5Ce5TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that ZrO(NO3)2-xH2O was mixed with 5 mol.% of Ce(NO3)3-6H2O and 5 mol.% of Ti(SO4)2 in deionized water.

[0055] Example 11

[0056] A Ni / 7Ce3TiZrO2 catalyst was prepared, following the same procedure as Example 1, with the only difference being that ZrO(NO3)2-xH2O was mixed with 7 mol.% of Ce(NO3)3-6H2O and 3 mol.% of Ti(SO4)2 in deionized water.

[0057] Comparative Example 1

[0058] The Ni / ZrO2 catalyst was prepared using the same steps as in Example 1, except that Ce(NO3)3·6H2O was not added.

[0059] The catalyst of Comparative Example 1 was tested in conjunction with the catalysts of Examples 3 and 7. Figure 1 As shown, comparing the XRD patterns of the three catalysts reveals that after the introduction of Ce and Ti, no diffraction peaks belonging to CeO2 and TiO2 were observed. Only the ZrO2 support underwent a phase structure transformation and shift, indicating that Ce... 4+ and Ti 4+ Replaced Zr 4+ It was successfully inserted into the ZrO2 lattice, forming Ce-O-Zr and Ti-O-Zr coordination structures, rather than forming a mixed oxide.

[0060] like Figure 2 As shown, comparing the TEM images of the three catalysts, lattice fringes (0.203 nm) on the Ni (111) plane were observed near ZrO2 in all three catalysts, indicating the formation of a Ni-O-Zr interface between Ni and ZrO2. Furthermore, the lattice spacing of the m-ZrO2 (-111) plane in the Ni / 5CeZrO2 catalyst (0.316 nm) was observed to shrink to 0.307 nm, and the lattice spacing of the t-ZrO2 (101) plane in the Ni / 10TiZrO2 catalyst was slightly reduced compared to the lattice spacing (0.295 nm) in the standard card. Therefore, this indicates that Ce and Ti are inserted into the ZrO2 lattice to replace Zr atoms, forming Ni / ZrO2 with Ce-O-Zr and Ti-O-Zr coordination structures, rather than being a simple mixture of two oxides.

[0061] like Figure 3 As shown, comparing the spectra of the three catalysts, the Zr 3d spectrum exhibits two distinct peaks at 181.8 and 184.1 eV, corresponding to Zr... 3+ 3D of Species 5 / 2 and 3D 3 / 2 Orbit. After adding Ce, Zr 3+ The binding energy of species decreases, while the addition of Ti increases Zr. 3+ The binding energy of species increases. This is because Ce (1.12) has a lower electronegativity than Zr (1.4), while Ti (1.54) has a higher electronegativity than Zr (1.4). Therefore, electrons in the formed Ce-O-Zr bond are attracted to Zr, while electrons around Zr in the Ti-O-Zr bond are dispersed, thus changing the electronic state of ZrO2 itself. 3+and Zr 4+ The species content also proves this.

[0062] Comparative Example 2

[0063] The Ni / 5CeO2-ZrO2 catalyst was prepared as follows:

[0064] 1) ZrO(NO3)2.xH2O was prepared into a solution with a concentration of 0.4 mol / L, 16.817 g of urea was added, and the mixture was stirred until completely dissolved to obtain a mixed solution; the obtained mixed solution was transferred into a 100 mL reactor, heated at 150°C for 12 h, and after filtration, the obtained powder sample was dried at 100°C overnight. Then, the dried powder was dissolved in deionized water, 5 mol.% of Ce(NO3)3.6H2O was added, and the liquid was evaporated after being stirred for 6 h. The obtained powder was dried at 100°C overnight and then calcined in an O2 / Ar mixed atmosphere at 600°C for 4 h to obtain a 5CeO2-ZrO2 support.

[0065] 2) 1 g of the 5CeO2-ZrO2 support and 1.2 g of Ni(NO3)2.6H2O were added to a certain amount of deionized water, stirred for 10 h, and then rotary evaporated, dried at 100°C overnight, and calcined in an O2 / Ar mixed atmosphere at 400°C for 4 h to obtain a Ni / 5CeO2-ZrO2 catalyst.

[0066] Comparative Example 3

[0067] The Ni / 10TiO2-ZrO2 catalyst was prepared in the same way as in Comparative Example 2, except that Ce(NO3)3.6H2O was replaced by Ti(SO4)2, and the amount of addition was 10 mol.%.

[0068] The catalysts prepared in Examples 1-11 and Comparative Examples 1-3 were applied to the preparation of biodiesel by directional regulation of the hydrogenation deoxygenation of biological oils and fats, and the specific steps were as follows:

[0069] A fixed bed reactor was selected, palm oil was dissolved in n-decane to obtain a palm oil solution with a mass concentration of 10 wt.%, and the palm oil solution with a hydrogen / oil ratio of 300:1 was mixed with hydrogen and injected into a fixed bed device containing an atomically substituted zirconia supported Ni catalyst for hydrogenation deoxygenation reaction. The catalyst amount was 0.5 g, the reaction pressure was 0.2 MPa, the reaction temperature was 240°C, the mass space velocity was 2 h -1 , and the catalytic biological oils and fats were hydrogenated and deoxygenated to generate biodiesel.

[0070] The specific reaction results are as follows:

[0071] Table 1 Comparison of catalytic properties of different catalysts

[0072]

[0073] As can be seen from the above table, by using the Ni / ZrO2 supported catalyst, by introducing Ce atoms and Ti atoms into the ZrO2 lattice to replace Zr atoms to form corresponding Ce-O-Zr and Ti-O-Zr bonds, the electronic state and chemical properties of the ZrO2 carrier itself are adjusted by the bond bridge, and then the Ni / ZrO2 catalyst is modified in a targeted manner, and the controllable adjustment of the bio-oil hydrogenation deoxygenation activity and product selectivity is realized. In the process of catalytic bio-oil hydrogenation deoxygenation to generate bio-diesel, the electron transfer from Ce to Zr in the Ce-O-Zr bond makes the Zr around it enriched with more electrons, which is beneficial to the adsorption of oxygen-containing groups in bio-oil on one hand, and the electronic effect of Zr-O-Ni interface promotes the electronic rearrangement of Ni sites to Ni 0 , enhances the dissociation of H2 and the breaking of C-C bond, thereby improving the hydrogenation deoxygenation activity and decarboxylation (DCO) selectivity. The enrichment of electrons around Zr by Ti in the Ti-O-Zr bond increases the content of hydroxyl groups on the surface of the ZrO2 carrier, thereby enriching the Br nsted acid sites on the surface of the catalyst, promoting the breaking of C-O / C=O, and thereby improving the direct hydrogenation deoxygenation (HDO) selectivity. In comparison, the Ni / 5CeO2-ZrO2 and Ni / 10TiO2-ZrO2 catalysts with simple composite oxides as the carrier cannot form corresponding bonds, and therefore cannot realize the targeted regulation of the bio-oil hydrogenation deoxygenation activity and product selectivity.

[0074] Therefore, the present application provides a method for targeted regulation of bio-oil hydrogenation deoxygenation to prepare bio-diesel, which regulates the chemical properties of the catalyst by using the adjuvants Ce and Ti to functionalize the carrier of the Ni / ZrO2 catalyst, realizes the controllable adjustment of the bio-oil hydrogenation activity and product selectivity, improves the selectivity of the target alkane component, and obtains high-quality bio-diesel. At the same time, it provides a method for the design of catalysts for selective conversion in the bio-oil hydrogenation deoxygenation system, especially for product selection, and has many advantages such as cleanliness, high reserves, and low cost.

[0075] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for the directed regulation of the production of biodiesel from the hydrodeoxygenation of biological oils, characterized in that, The method comprises the following steps: The biological oil is dissolved in a solvent to obtain a mixed solution with a mass concentration of 1.0-20%, the mixed solution is mixed with hydrogen, and then injected into a fixed bed reactor, and a Ni catalyst supported on an atom-substituted zirconia is used to perform a hydrodeoxygenation reaction, the coordination structure of the carrier and the heteroatom in the Ni catalyst supported on the atom-substituted zirconia is changed, the biological oil is controlled to be directed to generate an alkane with a corresponding carbon number or an alkane with one less carbon atom, and thus the biodiesel is obtained. The chemical formula of the Ni catalyst supported on the atom-substituted zirconia is Ni / xMZrO2, x is the molar percentage of M in the carrier, and is 1-20%; M is one or both of Ce and Ti, and the loading amount of Ni is 5-50 wt.%. The preparation steps of the Ni catalyst supported on the atom-substituted zirconia are as follows: 1) One or both of a zirconium salt, a cerium salt or a titanium salt are mixed in deionized water to obtain a metal precursor salt solution, then urea is added and fully stirred to dissolve, and a mixed solution is obtained; the mixed solution is placed in a reaction kettle and heated, filtered to obtain a precipitate, washed and dried, and then calcined in an O2 / Ar mixed atmosphere to obtain an atom-substituted zirconia carrier; 2) The obtained atom-substituted zirconia carrier and a nickel salt are added to deionized water, uniformly stirred, rotary evaporated, dried, and then calcined in an O2 / Ar mixed atmosphere to obtain the Ni catalyst supported on the atom-substituted zirconia.

2. The method for preparing biodiesel by directional regulation of hydrodeoxygenation of biological oil according to claim 1, characterized in that: In the specific preparation step 1) of the atom-substituted zirconia carrier, the molar ratio of urea to the metal precursor salt solution is 10:1, the heating temperature in the reaction kettle is 120-180℃, the heating time is 10-20h, the calcination temperature is 500-650℃, and the calcination time is 3-5h.

3. The method for preparing biodiesel by directional regulation of hydrodeoxygenation of biological oil according to claim 1, characterized in that: The biological oil is one or more of palm oil, soybean oil and rapeseed oil.

4. The method for preparing biodiesel by directional regulation of hydrodeoxygenation of biological oil according to claim 1, characterized in that: The solvent is one or more of n-decane, cyclohexane and n-heptane.

5. The method of claim 1, wherein the method is characterized by: Before the hydrodeoxygenation reaction, the Ni catalyst supported on the atom-substituted zirconia is in-situ reduced in the fixed bed reactor for 1.5-2.5h, and the reduction temperature is 300-400℃.

6. The method for preparing biodiesel by directional regulation of hydrodeoxygenation of biological oil according to claim 1, characterized in that: The concentration of the biological oil is 1.0-20wt.%, the temperature is 160-300℃, the hydrogen pressure is 0.2-4MPa, the mass space velocity is 0.2-4.8h -1 , and the ratio of hydrogen to the biological oil is 200-800:1.

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