阅读说明：本技术 一种重油制备中间相沥青和中间相炭微球的方法 (Method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil ) 是由 刘�东 龚鑫 李志浩 丁媛媛 张恒 于 2021-01-13 设计创作，主要内容包括：本发明涉及一种重油制备中间相沥青和中间相炭微球的方法,以重质油为原料,经正庚烷萃取分离出不溶物,在脱沥青油中掺杂3wt％～15wt％的生物质浅度交联后,减压深拔得到>450℃馏分的缩聚重产物,添加0～200μg/g的正庚烷不溶物和1wt％～10wt％自由基催化剂经二者协同诱导缩聚得到广域中间相沥青,取不同筛分目数的中间相沥青颗粒加至高沸点分散介质中,乳化成球,经洗涤干燥后得到中间相炭微球。本发明专利以重质油、生物质分子为原料,实现了对两者的有效利用,利用生物质分子的高反应活性基团实现了对炭微球收率、粒径分布、球度的优化,此方法经济性强,操作简单,具有较高的工业应用价值。(The invention relates to a method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil, which comprises the steps of taking heavy oil as a raw material, extracting and separating insoluble substances by n-heptane, doping 3-15 wt% biomass in deasphalted oil, then carrying out shallow crosslinking, carrying out deep drawing under reduced pressure to obtain a polycondensation heavy product of fractions with the temperature of more than 450 ℃, adding 0-200 mug/g of n-heptane insoluble substances and 1-10 wt% of free radical catalyst, carrying out synergistic induction polycondensation to obtain wide-area mesophase pitch, adding mesophase pitch particles with different screening meshes into a high-boiling-point dispersion medium, emulsifying to form spheres, washing and drying to obtain the mesophase carbon microspheres. The invention takes heavy oil and biomass molecules as raw materials, realizes effective utilization of the heavy oil and the biomass molecules, realizes optimization of yield, particle size distribution and sphericity of the carbon microspheres by utilizing high-reactivity groups of the biomass molecules, and has the advantages of strong economy, simple operation and higher industrial application value.)

1. A method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil takes one or more of medium-low temperature coal tar, high temperature coal tar and fractions thereof, heavy oil fractions, vacuum residue oil and FCC slurry oil as raw materials, and is characterized by comprising the following steps:

(1) extracting raw materials by n-heptane to separate out insoluble substances, doping biomass in deasphalted oil, carrying out shallow crosslinking at the reaction temperature of 300-380 ℃ under the protection of inert gas for 1-6 h, and then carrying out deep drawing under reduced pressure to obtain a polycondensation heavy product with a component at the temperature of more than 450 ℃;

(2) adding an n-heptane insoluble substance and a free radical catalyst into the polycondensation heavy product, and performing synergistic induction polycondensation on the n-heptane insoluble substance and the free radical catalyst at the reaction temperature of 400-450 ℃, the reaction pressure of 0.1-6 MPa and the reaction time of 8-12 h to obtain wide-area mesophase pitch;

(3) after cooling to normal temperature, crushing and sieving the mesophase pitch, uniformly dispersing the mesophase pitch particles with different sieving meshes into a high-boiling-point dispersion medium, wherein the proportion of the mesophase pitch particles to the high-boiling-point dispersion medium is 1: 10-1: 100g/ml, emulsifying the mesophase pitch particles into spheres under the conditions of reaction temperature of 300-350 ℃, heat preservation for 0.5-2 h and stirring speed of 400-600 r/min, and washing and drying to obtain the mesophase carbon microspheres.

2. The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil according to claim 1, wherein: the biomass in the step (1) comprises one or more of natural materials containing lignin, cellulose or chitosan and biomass pyrolysis oil, and the addition amount of the biomass in the step (1) is 3-15 wt% of the mass of the deasphalted oil.

3. The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil according to claim 1, wherein: the free radical catalyst in the step (2) comprises HF/BF₃Anhydrous AlCl₃、FeCl₃、NiCl₃、ZnCl₂、Fe(NO₃)₃、Ni(NO₃)₃One or more of the components, the addition amount is 1 wt% -10 wt% of the polycondensation heavy product, the addition amount of the n-heptane insoluble substance is 0-200 mug/g, the mesophase content of the wide-area mesophase pitch prepared is 80-100%, and the softening point is 200E250℃。

4. The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil according to claim 1, wherein: the boiling point of the high-boiling point dispersion medium in the step (3) is more than 350 ℃, and the high-boiling point dispersion medium comprises one or more of alkyl naphthalene conduction oil, benzyl biphenyl conduction oil, dibenzyl methyl high-heat oil, methyl silicone oil and methyl phenyl silicone oil.

5. The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil according to claim 1, wherein: the yield of the mesophase carbon microsphere obtained in the step (3) is 50-70%, and the added raw material mesophase pitch particles are controlled to be more than 200 meshes, so that the mesophase pitch particles can be used for producing carbon microsphere products with the median diameter of 12-62 mu m.

6. The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil according to claim 5, wherein: the added raw material mesophase pitch particles are controlled to be 200-300 meshes, and the carbon microsphere product with the median diameter of 48-62 mu m can be produced; the added raw material mesophase pitch particles are controlled to be 300-400 meshes, and the carbon microsphere product with the median diameter of 38-48 mu m can be produced; the added raw material mesophase pitch particles are controlled to be 400-500 meshes and can be used for producing carbon microsphere products with the median diameter of 29-38 mu m; the added raw material mesophase pitch particles are controlled to be 500-600 meshes, and the carbon microsphere product with the median diameter of 20-29 mu m can be produced; the added raw material mesophase pitch particles are controlled to be larger than 600 meshes, and the carbon microsphere product with the median diameter of 12-20 mu m can be produced.

7. Mesophase pitch and mesophase carbon microbead products produced by the process of any of claims 1-6.

8. The use of the mesophase pitch and the mesophase carbon microsphere product according to claim 7 in high performance materials, wherein the high performance materials comprise high specific surface active carbon materials, high efficiency adsorption materials, catalyst carriers, and lithium ion batteries.

Technical Field

The invention relates to a method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil, in particular to a preparation process of high-quality mesophase carbon microspheres by using heavy oil as a raw material and preparing the mesophase carbon microspheres by a primary induction polycondensation-collaborative pyrolysis-emulsification ternary combination process, belonging to the field of carbon material preparation.

Background

Petroleum, as the 'blood' of modern industry, plays an immeasurable role in the social and economic development and national defense safety of China. With the upgrading of global crude oil resources, increasingly intractable heavy oils are emerging from petroleum refining processes. The preparation of the carbon material with great development potential and application prospect is an effective utilization mode for heavy oil. The biofuel as a potential energy source capable of partially replacing fossil fuel has the advantages of being green, renewable, free of sulfur and the like, but the production cost is generally high. The biomass and the heavy oil are refined together, so that the biomass can be efficiently utilized, the problem of petroleum shortage is relieved, and good economic and environmental benefits are achieved. The co-refining of the biomass and the heavy oil can effectively reduce the investment cost of a refinery by utilizing the existing equipment of the refinery so as to reduce the production cost.

The mesophase pitch is a complex aromatic hydrocarbon aggregate, is a nematic liquid crystal, and is a precursor with excellent performance due to good plasticity and processability. Particularly, with the rise of new energy industry and the rapid development of lithium ion batteries, mesophase pitch serving as a novel cathode material also has a very wide development space. The mesocarbon microbeads are spherical or spheroidal structures formed by polycyclic aromatic hydrocarbon planar macromolecules under the action of surface free energy, and the main preparation methods comprise a polycondensation method, an emulsification method and a suspension method. The high-quality mesophase carbon microspheres are increasingly receiving attention of people because of having high strength, ultrahigh specific surface area and adsorption capacity, good spherical characteristics, uniform particle size, good chemical stability, thermal stability, heat conductivity and the like.

The high-quality mesocarbon microbeads can be used as a matrix of a plurality of composite materials as a high-quality carbon material precursor, and are widely applied to the field of preparation of high-performance materials, such as high-surface-area activated carbon materials, high-efficiency adsorption materials, catalyst carriers, lithium ion batteries and the like. However, the production and preparation processes have the problems of low yield, high cost, severe corrosion to equipment and the like, the industrial production of the mesophase carbon microspheres is deeply limited, and the morphology and the polycondensation degree of the current industrially produced mesophase carbon microspheres cannot reach the standard of high-performance application, so the research and development of the high-quality mesophase carbon microspheres are reluctant.

The patent CN108821275A discloses a high-capacity and high-rate graphite negative electrode material for a lithium ion battery and a preparation method thereof, asphalt and biomass tar are used as raw materials and are prepared by cross-linking, polycondensation and graphitization treatment at 3000-3200 ℃ under an inert atmosphere. Patent CN110357069A discloses a method for preparing mesocarbon microbeads by an emulsification method, which comprises preparing a solvent system by using a hydrogen donor solvent, a modified catalyst and an emulsifying solvent; secondly, adding medium-low temperature coal tar pitch into a solvent system to prepare mesophase pitch; finally extracting the mesophase pitch by using an organic solvent, drying, pre-oxidizing in air atmosphere, and carrying out N₂Carbonizing and graphitizing under the atmosphere to obtain the mesocarbon microbeads. The method has high requirements on reaction conditions, complex process flow and unsatisfactory graphitization degree. CN104108697A discloses a preparation method of mesophase pitch carbon microspheres, which comprises the steps of adding crushed raw materials and silicone oil into a high-pressure reaction kettle according to a certain proportion; gradually raising the temperature to a preset temperature in an inert gas atmosphere at a certain stirring speed; keeping the temperature for a period of time, then turning off the heating, and naturally cooling to room temperature; separating the mesocarbon microbeads from the heat-conducting medium silicone oil by a centrifugal separation method. Then preparing a final sample through carbonization and graphitization. Also has the disadvantages of non-ideal graphitization degree and complex process.

Disclosure of Invention

The invention provides a method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil, which is characterized in that heavy oil is taken as a raw material, n-heptane extraction oil is taken to dope biomass, shallow crosslinking and synergetic polycondensation are carried out to prepare high-quality mesophase pitch, and then the high-quality mesophase pitch is taken as a raw material and is emulsified to prepare the high-performance mesophase carbon microspheres, so that the source of the raw material is enlarged, and the method is a preparation process of the high-quality mesophase carbon microspheres.

The invention discloses a method for preparing mesophase pitch and mesophase carbon microspheres from heavy oil, which takes one or more of medium-low temperature coal tar, high-temperature coal tar and fractions thereof, heavy oil fractions, vacuum residue oil and FCC slurry oil as raw materials and comprises the following steps:

(1) extracting raw materials by using n-heptane to separate out n-heptane insoluble substances, doping biomass in deasphalted oil, carrying out shallow crosslinking at the reaction temperature of 300-380 ℃ under the protection of inert gas for 1-6 h, and then carrying out deep drawing under reduced pressure to obtain a polycondensation heavy product with a component of more than 450 ℃;

(2) adding an n-heptane insoluble substance and a free radical catalyst into the polycondensation heavy product, and performing synergistic induction polycondensation on the n-heptane insoluble substance and the free radical catalyst at the reaction temperature of 400-450 ℃, the reaction pressure of 0.1-6 MPa and the reaction time of 8-12 h to obtain wide-area mesophase pitch;

(3) after cooling to normal temperature, crushing and sieving the mesophase pitch, taking mesophase pitch particles with different sieving meshes, adding the mesophase pitch particles into a dispersion medium under the condition that the ratio of the mesophase pitch particles to the dispersion medium is 1: 10-1: 100g/ml, emulsifying the mesophase pitch particles into balls under the conditions that the reaction temperature is 300-350 ℃, the heat preservation is 0.5-2 h, and the stirring speed is 400-600 r/min, and washing and drying to obtain the mesophase carbon microspheres.

In the step (1), the biomass comprises one or more of natural materials containing lignin, cellulose and chitosan and biomass pyrolysis oil, and the addition amount of the biomass is 3-15 wt% of the deasphalted oil.

The radical catalyst in the step (2) comprises HF/BF₃Anhydrous AlCl₃、FeCl₃、NiCl₃、ZnCl₂、Fe(NO₃)₃、Ni(NO₃)₃One or more of the above components are added in an amount of 1-10 wt% of the polycondensation product, and the n-heptane insoluble substance is added in an amount of 0-200 mug/g, preferably 20-180 mug/g, so that the mesophase content of the wide-area mesophase pitch is 80-100%, and the softening point is 200-250 ℃.

And (3) screening 200-600-mesh intermediate phase asphalt particles by using a high-boiling-point dispersion medium with a boiling point higher than 350 ℃ and comprising one or more of alkyl naphthalene conduction oil, benzyl biphenyl conduction oil, dibenzyl methyl high-thermal oil, methyl silicone oil and methyl phenyl silicone oil, and highly dispersing the intermediate phase asphalt particles in the dispersion medium.

The yield of the mesocarbon microbeads obtained in the step (3) is 50-70%, the added raw material mesocarbon asphalt particles are controlled to be 200-300 meshes, and the mesocarbon microbeads with the median diameter of 48-62 mu m can be produced; the added raw material mesophase pitch particles are controlled to be 300-400 meshes, and the mesophase pitch particles can be used for producing mesophase carbon microsphere products with the median diameter of 38-48 mu m; the added raw material mesophase pitch particles are controlled to be 400-500 meshes and can be used for producing mesophase carbon microsphere products with the median diameter of 29-38 mu m; the added raw material mesophase pitch particles are controlled to be 500-600 meshes, and the mesophase pitch particles can be used for producing mesophase carbon microsphere products with the median diameter of 20-29 mu m; the added raw material mesophase pitch particles are controlled to be larger than 600 meshes, and the mesophase pitch particles can be used for producing mesophase carbon microsphere products with the median diameter of 12-20 mu m.

The invention also provides the mesophase pitch and the mesophase carbon microsphere product prepared by the method, and application of the mesophase pitch and the mesophase carbon microsphere product in high-performance materials, wherein the high-performance materials comprise a high-specific surface active carbon material, a high-efficiency adsorption material, a catalyst carrier and a lithium ion battery.

The mesophase carbon microspheres are prepared by adopting a ternary combination process of shallow crosslinking-synergistic polycondensation-emulsification, the composition of heavy oil raw materials is complex, the thermal polycondensation reaction activity of the composition molecules is not uniform, and if direct thermal polycondensation is caused, the phenomenon that the particle size distribution of mesophase spheres is too wide and is fused and serious can occur, so that n-heptane insoluble substances with higher reaction activity are firstly separated by solvent extraction, then biomass materials are added for preliminary induction polycondensation, and as the biomass pyrolysis products contain more active oxygen-containing groups, the oxidation crosslinking can be carried out on the biomass pyrolysis products and aromatic hydrocarbon molecules in residual oil, so that the aromaticity and the reaction activity of the intermediate products are increased; then adding a free radical catalyst and n-heptane insoluble substances for synergistic polycondensation, wherein the addition of the free radical catalyst can initiate a carbonium ion reaction at a lower temperature, promote a hydrogen transfer reaction in a system, effectively reduce the reaction rate and facilitate the ordered arrangement of aromatic molecule sheets, so that the softening point of the mesophase pitch can be reduced to a certain extent under the condition of ensuring higher content of an anisotropic structure, a small amount of n-heptane insoluble substances can be used as a nucleation promoter, the mesophase nucleation time can be shortened, the mesophase pitch in a wide area can be rapidly formed in a short time under the synergistic action of the two substances, and the yield of the mesophase pitch is improved. Then under the emulsification and dispersion action of a high-boiling point dispersion medium, the mesophase pitch particles can be emulsified to form the mesophase carbon microspheres with uniform particle size distribution. The method realizes high value-added utilization of biomass materials and inferior heavy oil, solves the problem of large-scale production and utilization of inferior residual oil and biomass, and reasonably allocates natural resources.

Compared with the prior preparation process, the process of the invention has the beneficial effects that:

(1) the invention takes heavy oil and biomass molecules as raw materials, and realizes the effective utilization of the heavy oil and the biomass molecules. The method has the advantages of high economy, high degree of freedom, simple operation and higher industrial application value.

(2) The high-reactivity groups of the biomass molecules are adopted to realize the oxidative crosslinking of aromatic molecules in the heavy oil, so that the molecular weight and the aromaticity of raw oil molecules are increased, and the wide-area mesophase pitch (low softening point and high mesophase content) can be prepared by further adopting a synergistic polycondensation reaction.

(3) By adopting a ternary combination process of shallow crosslinking, synergistic polycondensation and emulsification, the mesocarbon microbeads with uniform particle size distribution can be prepared, and the median diameter of the mesocarbon microbeads can be flexibly regulated and controlled by screening the mesopitch particles with different meshes.

Detailed Description

The method for preparing mesophase pitch and mesophase carbon microbeads by heavy oil provided by the present invention is further described below with reference to the following examples.

Example 1

Using medium-low temperature coal tar as raw material, extracting and separating raw oil by n-heptaneAdding 10g sawdust into 200g deasphalted oil, lightly crosslinking at 350 deg.C under nitrogen atmosphere for 5 hr, and deep-drawing under reduced pressure to obtain the final product>Heavy polycondensation products of components at 450 ℃; to the heavy polycondensation product were added 30mg of n-heptane-insoluble matter and 5g of HF/BF₃Obtaining wide-area mesophase pitch by the synergistic induction polycondensation of the two under the conditions of the reaction temperature of 440 ℃, the reaction pressure of 3MPa and the reaction time of 10h, wherein the mesophase content of the prepared wide-area mesophase pitch is 96.5 percent, and the softening point is 250 ℃; after cooling to normal temperature, crushing and sieving the mesophase pitch, uniformly dispersing 200-300-mesh mesophase pitch particles into alkyl naphthalene heat conduction oil, wherein the proportion of the mesophase pitch particles to a dispersion medium is 1:50(g/ml), emulsifying the mesophase pitch particles into balls under the conditions of reaction temperature of 350 ℃, heat preservation for 2 hours and stirring speed of 500r/min, and washing and drying to obtain the mesophase carbon microsphere product with the yield of 55% and the median diameter of 56 mu m.

Example 2

FCC oil slurry is used as raw material, raw oil is extracted by n-heptane to separate insoluble substances, 200g of deasphalted oil is doped with 15g of cellulose, shallow crosslinking is carried out at the reaction temperature of 350 ℃ under the nitrogen atmosphere for 5h, and the deasphalted oil is obtained by deep drawing under reduced pressure>Heavy polycondensation products of components at 450 ℃; to the polycondensation product were added 30mg of n-heptane-insoluble matter and 10g of NiCl₃Obtaining wide-area mesophase pitch by the synergistic induction polycondensation of the two under the conditions of reaction temperature of 430 ℃, reaction pressure of 3MPa and reaction time of 8h, wherein the mesophase content of the prepared wide-area mesophase pitch is 96.9 percent, and the softening point is 230 ℃; and after cooling to normal temperature, crushing and sieving the mesophase pitch, uniformly dispersing 300-400 meshes of mesophase pitch particles into the benzyl biphenyl heat conduction oil, wherein the ratio of the mesophase pitch particles to the dispersion medium is 1:55(g/ml), emulsifying the mesophase pitch particles into balls under the conditions of reaction temperature of 350 ℃, heat preservation for 2 hours and stirring speed of 500r/min, and washing and drying to obtain the mesophase carbon microsphere product with yield of 58% and median diameter of 44 mu m.

Example 3

Vacuum residue oil is used as raw material, raw oil is extracted by n-heptane to separate insoluble substances, and 200g deasphalted oil is doped with 15g of chitosanShallow crosslinking at 350 deg.C under nitrogen atmosphere for 5 hr, and deep drawing under reduced pressure>Heavy polycondensation products of components at 450 ℃; to the heavy polycondensation product were added 20mg of n-heptane insoluble matter and 10g of Fe (NO)₃)₃Obtaining wide-area mesophase pitch by the synergistic induction polycondensation of the two under the conditions of the reaction temperature of 420 ℃, the reaction pressure of 3MPa and the reaction time of 12h, wherein the mesophase content of the prepared wide-area mesophase pitch is 95.8 percent, and the softening point is 240 ℃; and after cooling to normal temperature, crushing and sieving the intermediate phase asphalt, uniformly dispersing 400-500-mesh intermediate phase asphalt particles into methyl silicone oil, wherein the ratio of the intermediate phase asphalt particles to a dispersion medium is 1:60(g/ml), keeping the temperature for 2h at the reaction temperature of 350 ℃, emulsifying the intermediate phase asphalt particles into balls under the condition of stirring speed of 500r/min, and washing and drying to obtain the intermediate phase carbon microsphere product with the yield of 60% and the median diameter of 32 mu m.

Example 4

High-temperature coal tar and fractions thereof are used as raw materials, raw oil is extracted by n-heptane to separate insoluble substances, 15g of sawdust is doped in deasphalted oil, shallow crosslinking is carried out at the reaction temperature of 350 ℃ under the nitrogen atmosphere for 5h, and deep drawing under reduced pressure is carried out to obtain the product>Heavy polycondensation products of components at 450 ℃; adding 30mg of n-heptane insoluble substances and 7g of anhydrous AlCl into the polycondensation product₃Obtaining wide-area mesophase pitch by the synergistic induction polycondensation of the two under the conditions of reaction temperature of 430 ℃, reaction pressure of 3MPa and reaction time of 8h, wherein the mesophase content of the prepared wide-area mesophase pitch is 95.3 percent, and the softening point is 240 ℃; after cooling to normal temperature, crushing and sieving the mesophase pitch, uniformly dispersing 500-600 meshes of mesophase pitch particles into dibenzyl methyl high-heat oil, wherein the proportion of the mesophase pitch particles to a dispersion medium is 1:65(g/ml), emulsifying the mesophase pitch particles into balls under the conditions of reaction temperature of 350 ℃, heat preservation for 2 hours and stirring speed of 500r/min, and washing and drying to obtain the mesophase carbon microsphere product with the yield of 60 percent and the median diameter of 22 mu m.