CN110586138A - High-dispersion vulcanized CoMoSxOyPreparation method and application of @ C bimetallic catalyst - Google Patents

Abstract

High-dispersion vulcanized CoMoS_xO_yA preparation method and application of a @ C bimetallic catalyst, belonging to the technical field of supported catalysts. The preparation method of the bimetal sulfuration state catalyst comprises the steps of selecting alpha-cellulose as a charcoal source, dispersing metal Co and Mo on the alpha-cellulose, drying, placing in a tubular furnace for slow in-situ pyrolysis to obtain a Co-MoO precursor with highly dispersed Co and Mo bimetal₂@ C; finally, vulcanizing the precursor to obtain the highly metal-dispersed charcoal-loaded CoMoS_xO_yA bimetallic sulfided catalyst. The advantages are that: the preparation process is simple, the raw materials are cheap and easy to obtain, the corrosivity to equipment and the solid waste treatment cost are reduced compared with those of non-supported metal sulfides, and the obtained catalyst is applied to catalytic hydrocracking of lignite-related model compounds and lignite, shows excellent activity and has good stabilityAnd the production period is short.

Description

High-dispersion vulcanized CoMoSxOyPreparation method and application of @ C bimetallic catalyst

Technical Field

The invention relates to the technical field of supported catalysts, in particular to high-dispersion vulcanized CoMoS_xO_yA preparation method and application of a @ C bimetallic catalyst.

Background

The direct liquefaction process of the lignite can obtain light tar with rich components from the lignite, is an important chemical raw material, can separate various chemicals such as carbazole, quinoline, phenol oil and the like from the lignite, can further upgrade the lignite into clean liquid fuel through catalytic hydrogenation conversion, and has great utilization space and utilization value. However, the yield of light tar obtained by the method still needs to be improved, and the selection of the catalyst has many concerns, such as the cost, stability and reactivity of the catalyst.

In the prior art, the sulfide Mo-based catalyst adopted by the direct lignite liquefaction process can be divided into two main types, namely an unsupported type and a supported type.

Unsupported, sulfided Mo-based catalysts, such as sulfided Co-Mo or Ni-Mo catalysts, can effectively activate H₂And promoting the transfer of active hydrogen and the subsequent cracking of lignite fragments>A C-O-bridge. However, such catalysts have a large amount of metal, and in order to ensure sufficient active sites on the substrate surface and edges, it is necessary to reduce the crystal thickness of the catalyst and increase the number of unsaturated sites, which leads to an increase in the cost. Furthermore, the specific surface area of such catalysts is generally low, which prevents contact between the active site and the substrate. The sulfur loss during the high-temperature reaction also causes corrosion of equipment and pollution of the environment to a certain extent.

The supported sulfurized Mo-base catalyst has carrier comprising active carbon and gamma-Al₂O₃And molecular sieves, etc., which can provide sites of high specific surface area and suitable pore channels, which promote mass transfer to some extent. Meanwhile, the mechanical strength of the catalyst is enhanced, and unnecessary active site loss is reduced. The supporting method is mostly a dipping method, and thenRoasting and sulfurizing to obtain sulfurized catalyst. However, the conventional impregnation method can only disperse part of metals on the surface of the carrier and in the medium/large pore channels, and cannot ensure that the active components are thoroughly and uniformly contacted with the carrier, and the blockage of the pore channels is not beneficial to the contact of active sites and a substrate, so that the catalytic hydrocracking activity is poor, and the tar yield is not high; in addition, hydrothermal sulfiding can also be used to obtain supported sulfided catalysts, but the large-scale production of the process is difficult to achieve and the dispersion of the active components is poor.

The existing preparation of lignite-related model compounds and lignite-related catalysts for catalytic hydrocracking has the problems of easy loss of active components, low catalytic activity, poor metal dispersion degree and the like.

Disclosure of Invention

The invention aims to provide high-dispersion vulcanized CoMoS which has relatively simple, safe and feasible preparation process and technique and can be produced in large scale_xO_yThe preparation method and the application of the @ C bimetallic catalyst solve the problems of poor mass transfer and poor metal dispersion degree in the traditional supported catalyst preparation.

The purpose of the invention is realized as follows: the preparation method of the bimetal sulfuration state catalyst comprises the steps of selecting alpha-cellulose as a charcoal source, dispersing metal Co and Mo on the alpha-cellulose, drying, placing in a tubular furnace for slow in-situ pyrolysis to obtain a Co-MoO precursor with highly dispersed Co and Mo bimetal₂@ C; finally, vulcanizing the precursor to obtain the highly metal-dispersed charcoal-loaded CoMoS_xO_yA bimetallic sulfided catalyst.

The preparation method comprises the following specific steps:

the method comprises the following steps: weighing Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂O, dispersing in the selected solution, and stirring at 60 ℃ for later use; the selected solution comprises any one of deionized water, methanol, ethanol or acetone;

step two: weighing 10-100g of alpha-cellulose, slowly adding the alpha-cellulose into the solution obtained in the first step, and continuously stirring for 24 hours until the alpha-cellulose is uniformly dispersed;

step three: removing the solution in the mixed system in the second step by reduced pressure distillation, then placing the mixed system into a forced air drying oven, and drying the mixed system for 4 hours at 120 ℃ to remove the residual solution;

step four: the powder dried in step three is then placed in a tube furnace under N₂Heating to 650 ℃ under the atmosphere and keeping for 4 h; cooling and taking out to obtain a highly dispersed bimetal precursor Co-MoO₂@C；

Step five: subjecting a bimetallic precursor Co-MoO₂@ C and calculated amount of sulfur powder are placed in high-pressure autoclave, and H is charged₂And vulcanizing to obtain the bimetallic vulcanized CoMoS_xO_y@ C catalyst.

In the first step, Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂The amount of O added is based on the mass ratio of Co to Mo being 1:3, and the total loading amount is 20 wt% of the carrier.

In the second step, the alpha-cellulose is a carbon source of the catalyst.

In the fourth step, N is required₂Heating to 650 ℃ and holding for 4h under an atmosphere is intended to ensure adequate pyrolysis of the alpha-cellulose and to promote high dispersion of the bimetal.

In the fifth step, the initial hydrogen pressure is 4MPa, the vulcanization temperature is 340 ℃, and the time is 4 hours, so as to ensure that the metal sulfide has enough thermal stability.

Charcoal-loaded CoMoS_xO_yThe application of the bimetallic sulfurized catalyst in the catalytic hydrocracking of lignite related model compound and lignite comprises the following steps:

the method comprises the following steps: 0g or 5g CoMoS_xO_yCatalyst and 20g of lignite powder are placed in a 1L high-pressure reaction kettle, and 200mL of cyclohexane is added;

step two: with N₂Replacing air in the kettle and filling 1MPa H₂Reacting for 4 hours at 320 ℃, finishing the reaction, and cooling by using an ice water bath;

step three: thoroughly extracting the reaction mixture by using petroleum ether with a boiling range of 30-60 ℃ to obtain petroleum ether soluble substances, namely light components;

step four: then, the extraction is continued by using the mixed solvent of acetone and carbon disulfide with the same volume, and soluble matters, namely heavy components, of the mixed solvent of acetone and carbon disulfide with the same volume are obtained.

The method has the beneficial effects that due to the adoption of the scheme, the Co and Mo metals are highly dispersed on the charcoal carrier and in the pore channel in an in-situ Co-pyrolysis mode, and the harsh H condition is avoided by the simple vulcanization process₂S or H₂And the use of flammable and explosive gases simplifies the preparation steps of the catalyst, and simultaneously solves the problems of poor mass transfer, poor metal dispersion degree and the like in the preparation of the traditional supported catalyst. The method embodies the atom economy and achieves the effects of lignite-related model compounds and the catalytic hydrocracking of lignite.

The method comprises the following steps of (1) using cheap and easily-obtained alpha-cellulose as a charcoal source, and impregnating Co and Mo metals on the alpha-cellulose according to a certain proportion by an impregnation method; co and Mo species are embedded into a charcoal carrier in an in-situ Co-pyrolysis manner; then obtaining the charcoal-loaded CoMoS through vulcanization_xO_yA bimetallic sulfided catalyst. The catalyst has high dispersion degree of two metals, and no obvious agglomeration after vulcanization. The preparation scheme provided by the invention has the advantages of simple and safe conditions and short production period. The catalyst is used for catalytic hydrocracking of lignite-related model compounds and lignite, shows excellent catalytic activity, and can effectively crack>C-O-bridge bond and remarkably improves the yield of the light tar derived from the lignite.

The problems of poor mass transfer and poor metal dispersion degree in the traditional supported catalyst preparation are solved, and the purpose of the invention is achieved.

The advantages are that: the preparation process is simple, the raw materials are cheap and easy to obtain, and compared with non-supported metal sulfides, the preparation process reduces the corrosivity on equipment and the solid waste treatment cost. The obtained catalyst is applied to catalytic hydrocracking of lignite related model compounds and lignite, shows excellent activity, and is good in stability and short in production period.

Drawings

FIG. 1 is an X-ray diffraction pattern of a biochar-supported Co, Mo or CoMo metal sulfided catalyst of the present invention.

FIG. 2 is a comparative transmission electron micrograph of a biochar-supported Co, Mo or CoMo metal sulfided catalyst of the present invention before and after sulfiding.

FIG. 3 is a biochar-loaded CoMoS of the invention_xO_yX-ray photoelectron spectroscopy of the catalyst.

FIG. 4 is a biochar-loaded CoMoS of the invention_xO_yThe tar yield chart of the catalyst used for lignite catalytic hydrocracking.

Detailed Description

Example 1: the preparation method of the bimetal sulfuration state catalyst comprises the steps of selecting alpha-cellulose as a charcoal source, dispersing metal Co and Mo on the alpha-cellulose, drying, placing in a tubular furnace for slow in-situ pyrolysis to obtain a Co-MoO precursor with highly dispersed Co and Mo bimetal₂@ C; finally, vulcanizing the precursor to obtain the highly metal-dispersed charcoal-loaded CoMoS_xO_yA bimetallic sulfided catalyst.

The preparation method comprises the following specific steps:

the method comprises the following steps: weighing Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂O, dispersing in the selected solution, and stirring at 60 ℃ for later use; the selected solution comprises any one of deionized water, methanol, ethanol or acetone;

step two: weighing 10-100g of alpha-cellulose, slowly adding the alpha-cellulose into the solution obtained in the first step, and continuously stirring for 24 hours until the alpha-cellulose is uniformly dispersed;

step three: removing the solution in the mixed system in the second step by reduced pressure distillation, then placing the mixed system into a forced air drying oven, and drying the mixed system for 4 hours at 120 ℃ to remove the residual solution;

step four: the powder dried in step three is then placed in a tube furnace under N₂Heating to 650 ℃ under the atmosphere and keeping for 4 h; cooling and taking out to obtain the precursor with highly dispersed bimetalBulk Co-MoO₂@C；

Step five: subjecting a bimetallic precursor Co-MoO₂@ C and calculated amount of sulfur powder are placed in high-pressure autoclave, and H is charged₂And vulcanizing to obtain the bimetallic vulcanized CoMoS_xO_y@ C catalyst.

In the first step, Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂The amount of O added is based on the mass ratio of Co to Mo being 1:3, and the total loading amount is 20 wt% of the carrier.

In the second step, the alpha-cellulose is a carbon source of the catalyst.

In the fourth step, N is required₂Heating to 650 ℃ and holding for 4h under an atmosphere is intended to ensure adequate pyrolysis of the alpha-cellulose and to promote high dispersion of the bimetal.

In the fifth step, the initial hydrogen pressure is 4MPa, the vulcanization temperature is 340 ℃, and the time is 4 hours, so as to ensure that the metal sulfide has enough thermal stability.

The charcoal-loaded CoMoS_xO_yThe application of the bimetallic sulfurized catalyst in the catalytic hydrocracking of lignite related model compound and lignite comprises the following steps:

the method comprises the following steps: 0g or 5g CoMoS_xO_yCatalyst and 20g lignite powder, wherein the coal is collected from a large yellow mountainous area of an autonomous region of Uygur autonomous region of Xinjiang, is placed in a 1L high-pressure reaction kettle, and 200mL of cyclohexane is added;

step two: with N₂Replacing air in the kettle and filling 1MPa H₂Reacting for 4 hours at 320 ℃, finishing the reaction, and cooling by using an ice water bath;

step three: thoroughly extracting the reaction mixture with petroleum ether with a boiling range of 30-60 deg.C to obtain petroleum ether soluble substance, i.e. light component, detecting, analyzing and comparing the light component, comparing non-catalytic and catalytic results shown in figure 4;

step four: and then continuously extracting with a mixed solvent of acetone and carbon disulfide with the same volume to obtain a soluble substance of the mixed solvent of acetone and carbon disulfide with the same volume, namely a heavy component, detecting, analyzing and comparing the heavy component, wherein the comparison of non-catalytic and catalytic results is shown in an attached figure 4.

CoMoS loaded on charcoal by combining attached drawing_xO_yThe preparation method, performance index and catalytic effect of the bimetallic sulfided catalyst are explained in detail, and the example is only for explaining the present invention and does not limit the protection scope of the present invention.

Example 2: charcoal-loaded CoMoS_xO_yCharacterization of the bimetallic sulfided catalyst.

FIG. 1 is an X-ray diffraction pattern (Bruker Advance D8XRD) of biochar-supported catalysts in different metal sulfids. As can be seen from fig. 1, the broad peak around 42o (100) in Activated Carbon (AC) confirms the formation of graphite. MoO before vulcanization₂@ C and Co-MoO₂The X-ray diffraction pattern of @ C corresponds to monoclinic MoO observed₂Characteristic diffraction peaks of the phases, including 26o (011), 37o (020), 53o (022), 60o (031), and 67o (-231). After vulcanization, ascribed to Co⁰The diffraction peak (about 44.5o) almost disappeared. In CoS_x@ C and CoMoS_xO_yThe characteristic diffraction peaks at @ C of about 27.9o, 29.9o, 30.5o and 51.9o are assigned to CoS respectively_1.097[JCPDS No.19-0366]、CoS[JCPDS No.65-0407]And C₉S₈[JCPDS No.02-1459]. As can be further seen from the figure, after vulcanization, it is assigned to MoO₂The characteristic diffraction peak of (A) was partially retained, indicating monoclinic MoO₂The phases are not completely converted to MoS during the short-time vulcanization_xPhase, but converted to mixed phase MoS_xO_y. Notably, in MoS_xO_y@ C and CoMoS_xO_yIn the XRD pattern of @ C due to MoO₂Diffraction peak ratio of MoO₂@ C and Co-MoO₂The narrow diffraction peak of @ C, which also explains to some extent the partial MoO₂Phase transition of the species. In detail, MoS_xO_y@ C and CoMoS_xO_yIn @ C, diffraction peaks near 33.0o, 50.6o and 58.3o are assigned to MoS, respectively₂[JCPDS No.17-0744]、Mo₃S₄[JCPDS No.27-0319]And Mo₇S₈[JCPDS No.51-1004]. These results demonstrate that the Co and Mo species in the catalyst prepared by the process of the invention are present in both the oxidation and sulfidation states.

FIG. 2 is a comparison of transmission electron microscope (JEM-200CX) photographs before and after the sulfidation of biochar-supported catalysts in different metal sulfided states. As can be seen from FIG. 2, both Co and Mo nanoparticles can be uniformly dispersed on the carbon matrix (Co @ C and MoO)₂@ C). The size of the Co nanoparticles is significantly smaller than that of the Mo nanoparticles. For Co-MoO₂@ C, Co and Mo nanoparticles were successfully and efficiently Co-dispersed on carbon substrates. After sulfidation, the metal nanoparticles were still uniformly dispersed without significant agglomeration, indicating that the metal nanoparticles can be effectively anchored to the carbon substrate by in situ co-pyrolysis in this manner. With Co-MoO₂@ C comparison, CoMoS_xO_yAbundant hierarchical pore structure appears in @ C, which means that CoMoS_xO_yThe pore characteristics of @ C vary significantly, which may be related to the phase change of Co and Mo species during sulfidation. In summary, the sulfided catalyst retains, to some extent, the previous morphological characteristics and new pore characteristics appear.

FIG. 3 is a charcoal-loaded CoMoS_xO_yX-ray photoelectron spectroscopy (Thermo Fisher Scientific K.alpha.1063 spectrometer) of the catalyst. Is attributed to Co⁰The diffraction peak (778.7eV) of (a) almost disappeared after vulcanization, which is in agreement with the analysis of X-ray diffraction. For CoMoS_xO_y@C，Coⁿ⁺The relative peaks of (794.3 and 778.9eV) shifted to the lower binding energy side, probably due to amorphous CoO_xTo CoS_xIs caused by the phase transition of (a). With Co-MoO₂The diffraction peaks attributed to Co-O-Mo species around 781.9eV are weaker compared to @ C, indicating that a portion of the doped lattice is destroyed during sulfidation. For Mo 3d, due to Mo⁶⁺And Mo²⁺The diffraction peak of (a) almost disappears, i.e. the multivalent Mo species is converted to Mo species with a normalized valence state (tending towards + 4). From Mo^δ+The weakening of the diffraction peak (232.5eV) induced further indicates that the Co-O-Mo doped lattice is more difficult to destroy, consistent with the analysis of Co 2 p. Furthermore, due to Mo⁴⁺The peak (229.4eV) also shifts to the low binding energy side, which means that Mo before and after vulcanization⁴⁺The species are completely different. This significant change in the diffraction band confirms that the proposed vulcanization process is feasible.

Example 3: charcoal-loaded CoMoS_xO_yThe application of the bimetallic sulfuration state catalyst and the catalytic hydrocracking of lignite related model compounds comprises the following operation steps:

(1) about 1mmol of substrate (phenylbenzyl ether or dibenzyl ether), 0.05g of catalyst in the sulfided state, and 20mL of n-hexane were placed in a 100mL stainless steel autoclave;

(2) using the autoclave with N₂Purging 3 times and with H at room temperature₂Pressurizing, wherein the initial hydrogen pressure is 1 MPa;

(3) subsequently, the autoclave was heated to 320 ℃ and maintained at 320 ℃ for 1h (for dibenzyl ether) or 2h (for phenylbenzyl ether);

(4) after the reaction was complete, the autoclave was cooled to room temperature with an ice-water bath, and the reaction mixture was removed and assayed.

As can be seen from Table 1, CoMoS compared to other supported, sulfided catalysts prepared in the same manner_xO_yThe @ C has the most excellent catalytic activity, and can effectively cut oxygen-containing bridge bonds in the dibenzyl ether and the phenyl benzyl ether to obtain the aromatic hydrocarbon or other oxygen-containing monomers with high yield. Wherein the conversion rate of the dibenzyl ether is 100 percent, the yield of the aromatic hydrocarbon is 199.5mol percent, the conversion rate of the phenyl benzyl ether is more than 85 percent, and the yield of the aromatic hydrocarbon and the yield of the phenols are both more than 85mol percent. Therefore, the catalyst synthesized by the method has the characteristics of high catalytic activity and selectivity, simplicity, easiness in obtaining and the like.

TABLE 1 Performance of highly dispersed sulfided catalysts for lignite-related model compounds catalyzed hydrocracking.

Example 4: charcoal-loaded CoMoS_xO_yThe application of the bimetallic sulfuration state catalyst and the catalytic hydrocracking of the lignite comprise the following operation steps:

the method comprises the following steps: 0g or 5g CoMoS_xO_yCatalyst and 20g lignite powder, wherein the coal is collected from a large yellow mountainous area of an autonomous region of Uygur autonomous region of Xinjiang, is placed in a 1L high-pressure reaction kettle, and 200mL of cyclohexane is added;

step two: with N₂Replacing air in the kettle and filling 1MPa H₂Reacting for 4 hours at 320 ℃, finishing the reaction, and cooling by using an ice water bath;

step three: thoroughly extracting the reaction mixture with petroleum ether with a boiling range of 30-60 deg.C to obtain petroleum ether soluble substance, i.e. light component, and detecting, analyzing and comparing the light component, with the result shown in figure 4;

step four: then, continuously extracting with a mixed solvent of acetone and carbon disulfide with the same volume to obtain a soluble substance of the mixed solvent of acetone and carbon disulfide with the same volume, namely a heavy component, and detecting, analyzing and comparing the heavy component, wherein the result is shown in an attached figure 4;

as can be seen from FIG. 4, the addition of CoMoS_xO_yAfter @ C, the yields of light tar and heavy tar are significantly improved. The yield of light tar and heavy tar is increased by more than 50%. Therefore, the catalyst designed by the invention can effectively promote the catalytic hydrocracking of the lignite and obtain high-yield tar.

The embodiments of the present invention are preferred embodiments, but not limited to the above-mentioned embodiments. Those skilled in the art can easily repeat the above-described embodiments and further applications and modifications without departing from the spirit of the present invention.

Claims (7)

1. High-dispersion vulcanized CoMoS_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: the preparation method of the bimetallic sulfuration catalyst selects alpha-cellulose as a biochar source and uses metal Co and Mo are dispersed on alpha-cellulose, dried and then placed in a tube furnace for slow in-situ pyrolysis to obtain a Co-MoO precursor with highly dispersed Co and Mo double metals₂@ C; finally, vulcanizing the precursor to obtain the highly metal-dispersed charcoal-loaded CoMoS_xO_yA bimetallic sulfided catalyst.

2. High dispersion vulcanized CoMoS according to claim 1_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: the preparation method comprises the following specific steps:

the method comprises the following steps: weighing Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂O, dispersing in the selected solution, and stirring at 60 ℃ for later use; the selected solution comprises any one of deionized water, methanol, ethanol or acetone;

step two: weighing 10-100g of alpha-cellulose, slowly adding the alpha-cellulose into the solution obtained in the first step, and continuously stirring for 24 hours until the alpha-cellulose is uniformly dispersed;

step three: removing the solution in the mixed system in the second step by reduced pressure distillation, then placing the mixed system into a forced air drying oven, and drying the mixed system for 4 hours at 120 ℃ to remove the residual solution;

step four: the powder dried in step three is then placed in a tube furnace under N₂Heating to 650 ℃ under the atmosphere and keeping for 4 h; cooling and taking out to obtain a highly dispersed bimetal precursor Co-MoO₂@C；

Step five: subjecting a bimetallic precursor Co-MoO₂@ C and calculated amount of sulfur powder are placed in high-pressure autoclave, and H is charged₂And vulcanizing to obtain the bimetallic vulcanized CoMoS_xO_y@ C catalyst.

3. High dispersion vulcanized CoMoS according to claim 2_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: in the first step, Co (NO)₃)₂·6H₂O and (NH)₄)₆Mo₇O₂₄·4H₂Amount of O addedBased on a mass ratio of Co to Mo of 1 to 3, the total loading was 20 wt% of the support.

4. High dispersion vulcanized CoMoS according to claim 2_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: in the second step, the alpha-cellulose is a carbon source of the catalyst.

5. High dispersion vulcanized CoMoS according to claim 2_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: in the fourth step, N is required₂Heating to 650 ℃ and holding for 4h under an atmosphere is intended to ensure adequate pyrolysis of the alpha-cellulose and to promote high dispersion of the bimetal.

6. High dispersion vulcanized CoMoS according to claim 2_xO_yThe preparation method of the @ C bimetallic catalyst is characterized by comprising the following steps of: in the fifth step, the initial hydrogen pressure is 4MPa, the vulcanization temperature is 340 ℃, and the time is 4 hours, so as to ensure that the metal sulfide has enough thermal stability.

7. A highly dispersed sulfurized CoMoS as defined in claim 1_xO_yThe application of the bimetallic catalyst prepared by the preparation method of the @ C bimetallic catalyst is characterized in that:

charcoal-loaded CoMoS_xO_yThe application of the bimetallic sulfurized catalyst in the catalytic hydrocracking of lignite related model compound and lignite comprises the following steps:

the method comprises the following steps: 0g or 5g CoMoS_xO_yCatalyst and 20g of lignite powder are placed in a 1L high-pressure reaction kettle, and 200mL of cyclohexane is added;

step two: with N₂Replacing air in the kettle and filling 1MPa H₂Reacting for 4 hours at 320 ℃, finishing the reaction, and cooling by using an ice water bath;

step three: thoroughly extracting the reaction mixture by using petroleum ether with a boiling range of 30-60 ℃ to obtain petroleum ether soluble substances, namely light components;

step four: then, the extraction is continued by using the mixed solvent of acetone and carbon disulfide with the same volume, and soluble matters, namely heavy components, of the mixed solvent of acetone and carbon disulfide with the same volume are obtained.