Method for preparing mesocarbon microbeads

Abstract

The application discloses a preparation method of mesocarbon microbeads. The method uses naphthenic heavy oil rich in aromatic hydrocarbons as raw material, adopts low-temperature thermal polycondensation process to prepare precursor pitch, and carries out ebullated bed hydrogenation treatment on the precursor pitch under suitable reaction conditions and in cooperation with suitable isomerization functional catalyst and molecular sieve catalyst to obtain refined aromatic hydrocarbon distillate oil with a boiling range greater than 400 DEG C. The refined aromatic hydrocarbon distillate oil is used as raw material to carry out catalytic polycondensation reaction under the double catalysis of aluminum salt of heteropoly acid catalyst and iron salt of heteropoly acid catalyst, and meso-pitch is obtained. The meso-pitch is extracted by an extraction solvent to remove isotropic pitch components, and carbon microbead green balls are obtained. Finally, the carbon microbead green balls are subjected to carbonization treatment, and mesocarbon microbeads are obtained. The application provides a novel aromatic hydrocarbon raw material refining process through technology coupling, has the advantages of wide raw material application range and high production efficiency, and opens up a new path for low-cost and high-quality mesocarbon microbeads.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of research on carbonaceous mesophase materials, and particularly relates to a preparation method of mesocarbon microbeads. BACKGROUND

[0002] In recent years, the world's crude oil resources have shown a trend of heavyization, especially the proportion of heavy oil with a density greater than 0.93 cm 3 / g gradually increases, which makes the production of heavy oil residues gradually increase in the petroleum refining process. These heavy oil residues have relatively complex structure and composition, a large range of molecular weight distribution, and a certain amount of S, N, O and heavy metal elements. It is difficult to achieve pollution-free and high-value utilization by using traditional refining processes, but heavy oil residues such as FCC oil slurry and ethylene tar are rich in short side chain polycyclic aromatic compounds (mainly 2-5 rings), which are considered to be potential high-quality raw materials for preparing mesophase carbon microspheres, needle coke, mesophase pitch-based carbon fibers, and foam carbon.

[0003] Mesocarbon microbeads (MCMB) are a kind of spherical micron-sized soft carbon material formed by parallel accumulation of planar condensed aromatic macromolecules. The particle size of MCMB is mainly distributed between 1-40 μm. The special structural characteristics of MCMB make it exhibit excellent electrochemical performance. The common structural type of MCMB is the structure of a globe (also known as Brook-Taylor type or latitude type). The internal carbon layers of this type of carbon microspheres are parallelly stacked, and the layered carbon layer structure produces a large intercalation lithium storage capacity. In addition, MCMB has a natural micron-sized spherical structure, which also enables MCMB to realize close packing and provide high volume energy density. Therefore, MCMB has an irreplaceable advantage compared to other anode materials for lithium ion batteries.

[0004] The patent CN109179371A provides a method for preparing mesophase carbon microspheres by using asphalt pyrolysis oil. The method obtains a raw oil rich in aromatic hydrocarbons by heat filtration coupled with solvent extraction, and then uses a thermal polycondensation process to prepare a product asphalt containing mesophase small balls. After solvent extraction, filtration, and high-temperature carbonization treatment, mesophase carbon microspheres are obtained. The method has a low yield of carbon microspheres, a wide range of microsphere particle size distribution, and a fusion and agglomeration phenomenon between carbon microspheres. The patent CN103613089A discloses a method for preparing mesophase carbon microspheres using coal liquefaction residue. The method first removes solid impurities in the coal liquefaction residue by solvent extraction process to obtain asphaltene-like substances. Then, a polycondensation solvent and a nucleating agent are added and heat-treated under certain reaction conditions to obtain a product asphalt containing mesophase small balls. After solvent washing, filtration, and drying, mesophase carbon microspheres are obtained. The method realizes efficient utilization of coal liquefaction residue, but the obtained mesophase carbon microspheres have a large particle size, poor sphericity, and low yield. The patent CN1308113A discloses a co-polycondensation method for preparing mesophase carbon microspheres. The method uses medium-temperature coal tar and petroleum heavy oil containing quinoline insoluble as raw materials to prepare a product asphalt containing mesophase small balls by co-polycondensation reaction under high temperature conditions. A mixed solution of coal tar and light fraction oil of petroleum is used as an extractant. After heat filtration and drying, mesophase carbon microspheres are obtained. However, the method has the disadvantages of large particle size of carbon microspheres, low yield, and difficulty in recycling the extractant.

[0005] In summary, some existing processes have problems such as uneven particle size distribution, poor sphericity, and low yield of mesophase carbon microspheres. In the extraction process, only organic solvents are generally used for extraction, resulting in high cost and difficulty in industrial production. Therefore, a new method for preparing high-quality mesophase carbon microspheres is needed to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a method for preparing mesophase carbon microspheres, which solves the problems of uneven particle size distribution, poor sphericity, and high cost of industrial production of carbon microspheres prepared by the prior art.

[0007] The technical solution adopted by the present application is a method for preparing mesophase carbon microspheres, comprising the following steps:

[0008] S1: using naphthenic rich aromatic heavy oil as raw material, adopting low-temperature thermal polycondensation process to prepare precursor asphalt;

[0009] S2: matching isomerization functional catalyst and molecular sieve catalyst to carry out ebullated bed hydrogenation treatment on the precursor asphalt, and then obtaining refined rich aromatic distillate oil by vacuum distillation process;

[0010] S3: taking refined aromatic hydrocarbon-rich distillate oil as raw material, conducting catalytic polycondensation reaction under double catalysis of aluminum salt of heteropoly acid and iron salt of heteropoly acid to obtain mesophase pitch containing mesophase small balls, and extracting the mesophase pitch by organic solvent or oil distillate to obtain carbon microsphere green balls;

[0011] S4: conducting carbonization treatment or pre-oxidation and carbonization treatment on the carbon microsphere green balls to obtain mesocarbon microbeads.

[0012] The application is also characterized in that the low-temperature thermal polycondensation process has a reaction temperature of 300-400 DEG C, a reaction time of 10-120 min and a reaction pressure of 0.1-3 MPa.

[0013] The ebullated bed hydrogenation process has a temperature of 380-460 DEG C, a hydrogen partial pressure of 0.5-6 MPa and a space velocity of 0.1-10 h-1. -1 -1 ;

[0014] The isomerization functional catalyst is selected from one or more of AlCl3, SbCl, acidified Al2O3 or molybdenum oxide, the molecular sieve catalyst is selected from silicon-aluminum molecular sieve or phosphorus-aluminum molecular sieve, and the molecular sieve catalyst is one or more of Pt, Pd or Ni;

[0015] The vacuum distillation process has a negative pressure of 1-5 mmHg, a theoretical column number of 5-20, a reflux ratio of 1:5-5:1 and a liquid phase distillation temperature of 330-350 DEG C.

[0016] The aluminum salt of heteropoly acid catalyst is selected from one or more of phosphorus-aluminum acid, silicon-aluminum acid or potassium salt of phosphorus-aluminum acid, and the addition amount of the aluminum salt of heteropoly acid catalyst is 0.5-5 wt%.

[0017] The iron salt of heteropoly acid catalyst is selected from one or more of phosphorus-iron acid, phosphorus-iron divanadic acid or phosphorus-iron trivanadic acid, and the addition amount of the iron salt of heteropoly acid is 0.5-5 wt%.

[0018] The catalytic polycondensation reaction has a temperature of 350-450 DEG C, a pressure of 0.1-3 MPa and a time of 2-10 h.

[0019] The organic solvent is selected from one or more of tetrahydrofuran, N-dimethylamide or dimethyl sulfoxide, and the solvent-oil ratio in the extraction process is 4:1-10:1.

[0020] The oil distillate is selected from gasoline distillate with a boiling range of 130-200 DEG C, diesel distillate with a boiling range of 200-350 DEG C or a mixed distillate of the two in a mass ratio of 5:1-1:5, and the solvent-oil ratio in the extraction process is 1:1-10:1.

[0021] ​The pre-oxidation treatment temperature is 220-280 DEG C, the oxygen flow is 100-300 ml / min, the pre-oxidation treatment time is 2-6 h; the carbonization temperature is 800-1600 DEG C, the nitrogen flow is 100-300 ml / min, and the carbonization treatment time is 0.5-3 h.

[0022] The beneficial effects of the present application are:

[0023] 1. The present application utilizes low-temperature thermal polycondensation process coupled with selective hydrogenation treatment to realize the regulation of the molecular structure composition of raw oil, improve the conversion efficiency of aromatic molecules in the later catalytic polycondensation process, realize the synchronous improvement of the microstructure characteristics and macroscopic performance of carbon microspheres, and obtain carbon microspheres with uniform particle size distribution and good sphericity;

[0024] 2. The present application provides a new aromatic-rich raw material refining process through technical coupling. The disclosed treatment method of aromatic-rich raw material can meet the processing needs of different properties of aromatic-rich raw oil, has the advantages of low industrial production cost, large operable space, high universality, uniform particle size distribution of finished carbon microspheres, and good sphericity, and opens up a new path for low-cost and high-quality industrialization of mesophase carbon microspheres. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the SEM image of mesophase carbon microspheres in Example 1;

[0026] Figure 2 is the average particle size distribution graph of mesophase carbon microspheres in Example 1;

[0027] Figure 3 is the SEM image of mesophase carbon microspheres in Example 2;

[0028] Figure 4 is the average particle size histogram of mesophase carbon microspheres in Example 2;

[0029] Figure 5 is the SEM image of mesophase carbon microspheres in Example 3;

[0030] Figure 6 is the average particle size histogram of mesophase carbon microspheres in Example 3. DETAILED DESCRIPTION

[0031] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0032] A preparation method of mesophase carbon microspheres, comprising the following steps:

[0033] S1: using naphthenic base rich aromatic heavy oil as raw material, precursor pitch is prepared by low temperature thermal polycondensation process; wherein, naphthenic base rich aromatic heavy oil can use catalytic cracking (FCC) slurry, ethylene tar, etc.; low temperature thermal polycondensation process reaction temperature is 300-400℃, reaction time is 10-120min, reaction pressure is 0.1-3MPa.

[0034] S2: precursor pitch is treated by ebullated bed hydrogenation with isomerization function catalyst and molecular sieve catalyst, then refined aromatic rich distillate oil is obtained by vacuum distillation process, and the refined aromatic rich distillate oil with boiling point greater than 400℃ is obtained; wherein, hydrogenation treatment temperature is 380-460℃, hydrogen partial pressure is 0.5-6MPa, space velocity is 0.1-10h -1 ~10h -1 ; isomerization function catalyst is selected from one or more of AlCl3, SbCl, acidified Al2O3, molybdenum oxide, and molecular sieve catalyst is selected from silicon-aluminum molecular sieve or phosphorus-aluminum molecular sieve with Pt, Pd or Ni as loading; wherein, vacuum distillation process vacuum is 1-5mmHg, theoretical plate number is 5-20, reflux ratio is 1:5-5:1, and liquid phase distillation temperature is 330-350℃.

[0035] S3: refined aromatic rich distillate oil is used as raw material, and intermediate pitch containing mesophase small balls is obtained by catalytic polycondensation reaction under the dual catalysis of heteropoly acid aluminum salt catalyst and heteropoly acid iron salt catalyst; isotropic pitch components are removed by extracting intermediate pitch with organic solvent or oil distillate to obtain carbon microsphere green balls;

[0036] wherein, heteropoly acid aluminum salt is selected from one or more of phosphorus aluminic acid, silicon aluminic acid or potassium phosphorus aluminic acid salt, and the addition amount of heteropoly acid aluminum salt is 0.5-1.5wt%, heteropoly acid iron salt is selected from one or more of phosphorus iron acid, phosphorus iron divanadic acid and phosphorus iron trivanadic acid, and the addition amount of heteropoly acid iron salt is 0.5-1.5wt%, catalytic polycondensation reaction temperature is 350-450℃, reaction pressure is 0.1-3MPa, and reaction time is 2-10h;

[0037] Further, organic solvent is selected from one or more of tetrahydrofuran, N-dimethylamide or dimethyl sulfoxide, and the solvent to oil ratio in the extraction process is 4:1-10:1; oil distillate is selected from gasoline distillate with boiling point 130-200℃, including straight-run gasoline distillate, catalytic cracking gasoline distillate or coking gasoline distillate, etc., or diesel distillate with boiling point 200-350℃, including straight-run diesel distillate, catalytic cracking diesel distillate or coking diesel distillate, etc., or a mixed distillate with mass ratio of 5:1-1:5, and the solvent to oil ratio in the extraction process is 1:1-10:1.

[0038] S4: the carbon microsphere green balls are subjected to carbonization treatment or pre-oxidation and carbonization treatment to obtain mesophase carbon microspheres with uniform particle size distribution and good sphericity;

[0039] In the application, the pre-oxidation treatment temperature is 220-280 DEG C, the oxygen flow is 100-300 ml / min, the pre-oxidation treatment time is 2-6 h, the carbonization temperature is 800-1600 DEG C, the nitrogen flow is 100-300 ml / min, and the carbonization treatment time is 0.5-3 h. It is worth noting that in actual production, carbonization treatment can be directly performed, or pre-oxidation treatment can be performed first and then carbonization treatment is performed. Pre-oxidation can reduce the burden of subsequent carbonization and can make the finished product yield higher or the quality better.

[0040] The application is aimed at the structural composition characteristics of naphthenic heavy oil, realizes the regulation of aromatic molecular structure composition by low-temperature thermal polycondensation process coupled with hydrogen treatment, and then realizes the enrichment of polycyclic aromatic hydrocarbon molecules with similar molecular weight and similar structure composition by means of vacuum distillation process to obtain refined aromatic-rich distillate oil. The low-temperature polycondensation treatment can improve the polycondensation degree of aromatic molecules to a certain extent, so that the number of aromatic rings in the molecules reaches 3-5. The moderate hydrogen treatment can significantly improve the number of alkyl side chains around the aromatic molecules, so that the aromatic molecules have high reactivity and are helpful to realize the rapid polycondensation of the aromatic molecules in the later high-temperature carbonization process. Heteropoly acid iron salt and heteropoly acid aluminum salt are selected as catalysts to prepare product pitch containing mesophase small balls under certain reaction conditions. In the reaction system, the addition of heteropoly acid aluminum salt can effectively stimulate the activation of raw oil molecules, reduce the reaction temperature, and avoid excessive polycondensation of mesophase pitch molecules. The heteropoly acid iron salt is both an initiator and a nucleating agent, which induces the generation of mesophase small balls and improves the conversion rate. At the same time, the pyrolysis products of the heteropoly acid aluminum salt and the heteropoly acid iron salt are adsorbed on the surface of the mesophase small balls, avoiding mutual fusion and improving the sphericity of the carbon microspheres and reducing the particle size distribution range of the carbon microspheres. The solvent extraction process is used to realize the separation of the mesophase small balls and the isotropic pitch components. In this way, the separation and enrichment of the mesophase small balls can be realized quickly, and the extracted isotropic pitch product can also be used as impregnated pitch, further expanding the application field of the raw oil.

[0041] Example 1:

[0042] 280g of catalytic cracking (FCC) oil slurry is added to a high-temperature high-pressure reaction kettle, and reacted at 300 DEG C and 0.1 MPa for 120 min; then the product pitch is transported to a boiling bed by using a pipeline pump, AlCl3 and Pt-loaded phosphorus-aluminum molecular sieve are used as catalysts, the reaction temperature is set to 420 DEG C, the hydrogen partial pressure is 4 MPa, the space velocity is 5h -1The hydrogenated product is transported to a vacuum distillation device for treatment under the conditions of a negative pressure of 1 mmHg, 5 theoretical plates, a reflux ratio of 1:5, and a liquid phase distillation temperature of 350℃, to obtain a refined aromatic-rich distillate oil with a boiling range greater than 400℃; 200g of the refined distillate oil is weighed and placed in a high-temperature and high-pressure reaction kettle, 1g of phosphorus aluminic acid and 1g of phosphorus ferric acid are added, and the mixture is reacted at 350℃ and 0.1MPa for 10h to obtain a two-phase coexisting pitch containing mesophase small balls; a 200℃ straight-run gasoline fraction is used as an extraction solvent, and the solvent-oil ratio is 1:1 during the extraction process; carbon microsphere green balls are obtained through multiple rinsing; then the carbon microsphere green balls are subjected to pre-oxidation treatment at a pre-oxidation temperature of 220℃, an oxygen flow rate of 100ml / min, and a pre-oxidation time of 6h; and then the carbon microsphere green balls are subjected to carbonization treatment at 800℃ in a nitrogen atmosphere for 3h, with a nitrogen flow rate of 100ml / min, to obtain carbon microspheres with an average particle size of 19.8μm, which have a uniform particle size distribution and good sphericity.

[0043] The SEM images and average particle size measurement statistical results of the mesophase carbon microspheres in Example 1 are shown in Figure 1 , Figure 2 .

[0044] Example 2:

[0045] 280g of ethylene tar is added to a high-temperature and high-pressure reaction kettle, and the mixture is reacted at 400℃ and 2MPa for 10min; then the product pitch is transported to a boiling bed using a pipeline pump, SbCl and Pd-loaded phosphorus aluminic molecular sieves are used as catalysts, the reaction temperature is set to 380℃, the hydrogen partial pressure is 0.5MPa, the space velocity is 0.1h -1 The hydrogenated product is transported to a vacuum distillation device for treatment under the conditions of a negative pressure of 5mmHg, 15 theoretical plates, a reflux ratio of 1:1, and a liquid phase distillation temperature of 340℃, to obtain a refined aromatic-rich distillate oil with a boiling range greater than 400℃; 200g of the refined distillate oil is weighed and placed in a high-temperature and high-pressure reaction kettle, 3g of phosphorus aluminic acid and 3g of phosphorus ferric acid are added, and the mixture is reacted at 450℃ and 3MPa for 2h to obtain a two-phase coexisting pitch containing mesophase small balls; a 250℃ straight-run diesel oil fraction is used as an extraction solvent, and the solvent-oil ratio is 10:1 during the extraction process; carbon microsphere green balls are obtained through multiple rinsing; then the carbon microsphere green balls are subjected to pre-oxidation treatment at a pre-oxidation temperature of 250℃, an oxygen flow rate of 200ml / min, and a pre-oxidation time of 4h; and then the carbon microsphere green balls are subjected to carbonization treatment at 1600℃ in a nitrogen atmosphere for 0.5h, with a nitrogen flow rate of 200ml / min, to obtain carbon microspheres with an average particle size of 15.5μm, which have a uniform particle size distribution and good sphericity.

[0046] The SEM images and average particle size measurement statistical results of the mesophase carbon microspheres in Example 2 are shown in Figure 3 , Figure 4 .

[0047] Example 3

[0048] 280 g of catalytic cracking slurry was added into a high-temperature and high-pressure reactor, and reacted at 350℃ and 3 MPa for 60 min; then the product asphalt was transported to a boiling bed by using a pipeline pump, and treated by using acidized Al2O3 and Ni-loaded phosphorus-aluminum molecular sieve as catalysts, with a reaction temperature of 460℃, hydrogen partial pressure of 6 MPa, and space velocity of 10 h-1. -1 The hydrogenated product was transported to a vacuum distillation device for treatment under the conditions of a negative pressure of 3 mmHg, 20 theoretical trays, a reflux ratio of 5:1, and a liquid phase distillation temperature of 330℃. 200 g of refined distillate oil was weighed and added into a high-temperature and high-pressure reactor, and 2 g of phosphorus-aluminum acid and 2.5 g of phosphorus-iron acid were added, and reacted at 400℃ and 2 MPa for 6 h to obtain two-phase coexisting asphalt containing mesophase small balls. The mixed distillate of 130℃ catalytic cracking gasoline distillate and 250℃ coking diesel distillate was used as an extractant, with a solvent-oil ratio of 5:1 during the extraction process. Carbon microsphere green balls were obtained by multiple rinsing, and then carbonization treatment was performed at 1200℃ under a nitrogen atmosphere for 2 h, with a nitrogen flow rate of 300 ml / min, to obtain carbon microspheres with an average particle size of 16.6 μm, and the particle size distribution was uniform and the sphericity was good.

[0049] The SEM image of the mesophase carbon microspheres in Example 3 and the statistical results of the average particle size measurement are shown in Figure 5 , Figure 6 .

[0050] Example 4

[0051] 280 g of catalytic cracking slurry was added into a high-temperature and high-pressure reactor, and reacted at 350℃ and 3 MPa for 60 min; then the product asphalt was transported to a boiling bed by using a pipeline pump, and treated by using acidized Al2O3 and Ni-loaded phosphorus-aluminum molecular sieve as catalysts, with a reaction temperature of 460℃, hydrogen partial pressure of 6 MPa, and space velocity of 10 h -1The hydrogenated product is transported to a vacuum distillation device for treatment, the negative pressure is 3mmHg, the theoretical tray is 20, the reflux ratio is 5:1, and the liquid phase distillation temperature is 330℃. 200g of refined distillate oil is weighed and placed in a high-temperature and high-pressure reaction kettle, 2g of phosphorus aluminum acid and 2.5g of phosphorus iron acid are added, and the reaction is carried out at 400℃ and 2MPa for 6h to obtain two-phase coexisting pitch containing mesophase small balls. The mixed distillate of the 130℃ catalytic cracking gasoline fraction and the 250℃ coking diesel oil fraction is used as the extraction agent, the agent oil ratio is 5:1 during the extraction process, and the carbon microsphere green balls are obtained by multiple washing. Different from example 3, the pre-oxidation is carried out first, and then the carbonization treatment is carried out, the pre-oxidation temperature is set to 280℃, the oxygen flow rate is 300ml / min, and the pre-oxidation time is 5h for pre-oxidation treatment, and then carbonization treatment is carried out at 1000℃ in a nitrogen atmosphere for 2h, wherein the nitrogen flow rate is 200ml / min, and the average particle size of the carbon microspheres is 16.8μm, the particle size distribution is uniform, and the sphericity is good (for reference, see the related pictures of example 3).

[0052] It can be seen from examples 1-4 that the mesophase carbon microspheres prepared by the present application have uniform particle size distribution, good sphericity, and high quality.

[0053] The purpose of the present application is to realize high-value utilization of naphthenic heavy oil and obtain high-quality mesophase carbon microspheres. The present application provides a preparation method of mesophase carbon microspheres, which uses naphthenic heavy oil as raw material, first uses low-temperature thermal polycondensation process to prepare precursor pitch, and then carries out boiling bed hydrogenation treatment on the precursor pitch under suitable reaction conditions with suitable isomerization functional catalyst and molecular sieve catalyst to obtain refined aromatic-rich distillate oil with a boiling range greater than 400℃. The refined aromatic-rich distillate oil is used as raw material, and a catalytic polycondensation reaction is carried out under the dual action of aluminum salt and iron salt of heteropoly acid catalyst to obtain product pitch containing mesophase small balls. Then, organic solvent and oil distillate are used for extraction to remove isotropic pitch components, and after pre-oxidation and carbonization treatment, mesophase carbon microspheres with uniform particle size distribution and good sphericity are obtained.

Claims

1. A method for producing mesocarbon microbeads, characterized by, It comprises the following steps: S1: using naphthenic base rich aromatic heavy oil as raw material, a precursor pitch is prepared by low-temperature thermal polycondensation process; S2: the precursor pitch is treated by ebullated bed hydrogenation treatment with isomerization functional catalyst and molecular sieve catalyst, and then a refined rich aromatic distillate oil is obtained by vacuum distillation process; S3: the refined rich aromatic distillate oil is used as raw material to carry out catalytic polycondensation reaction under the dual catalysis of aluminum salt of heteropoly acid catalyst and iron salt of heteropoly acid catalyst, and an intermediate pitch containing mesophase small balls is obtained, and then the intermediate pitch is extracted by an organic solvent or an oil fraction to obtain carbon microsphere green balls; S4: the carbon microsphere green balls are subjected to carbonization treatment or pre-oxidation and carbonization treatment, and then intermediate carbon microspheres are obtained. The low-temperature thermal polycondensation process in S1 has a reaction temperature of 300-400℃, a reaction time of 10-120 min, and a reaction pressure of 0.1-3 MPa. The boiling bed hydrogenation process temperature in S2 is 380℃-460℃, hydrogen partial pressure is 0.5 MPa-6 MPa, space velocity is 0.1 h -1 ~10h -1 .

2. The method of producing the MCMB according to claim 1, wherein: The isomerization functional catalyst is selected from one or more of AlCl3, SbCl, acidified Al2O3, and molybdenum oxide, and the molecular sieve catalyst is selected from silicon-aluminum molecular sieve or phosphorus-aluminum molecular sieve, and the molecular sieve catalyst is loaded with one or more of Pt, Pd, or Ni.

3. The method of producing the MCMB according to claim 1, wherein: The vacuum distillation process has a negative pressure of 1-5 mmHg, a theoretical column number of 5-20, a reflux ratio of 1:5-5:1, and a liquid phase distillation temperature of 330-350℃.

4. The method of producing the MCMB according to claim 1, wherein: The aluminum salt of heteropoly acid catalyst is selected from one or more of phosphorus-aluminum acid, silicon-aluminum acid, and potassium salt of phosphorus-aluminum acid, and the addition amount of the aluminum salt of heteropoly acid catalyst is 0.5-5 wt%.

5. The method of producing the MCMB according to claim 1, wherein: The iron salt of heteropoly acid catalyst is selected from one or more of phosphorus-iron acid, phosphorus-iron divanadic acid, and phosphorus-iron trivanadic acid, and the addition amount of the iron salt of heteropoly acid is 0.5-5 wt%.

6. The method of producing the MCMB according to claim 1, wherein: The catalytic polycondensation reaction has a reaction temperature of 350-450℃, a reaction pressure of 0.1-3 MPa, and a reaction time of 2-10 h.

7. The method of producing the MCMB according to claim 1, wherein: The organic solvent is selected from one or more of tetrahydrofuran, N-dimethylformamide, or dimethyl sulfoxide, and the solvent-oil ratio in the extraction process is 4:1-10:

1. The oil fraction is selected from gasoline fraction with a boiling range of 130-200℃, diesel fraction with a boiling range of 200-350℃, or a mixed fraction of the two with a mass ratio of 5:1-1:5, and the solvent-oil ratio in the extraction process is 1:1-10:

1.

8. The method of producing the MCMB according to claim 1, wherein: The pre-oxidation treatment temperature is 220-280℃, the oxygen flow rate is 100-300 ml / min, the pre-oxidation treatment time is 2-6 h, the carbonization temperature is 800-1600℃, the nitrogen flow rate is 100-300 ml / min, and the carbonization treatment time is 0.5-3 h.

Images