Process for processing catalytically cracked light cycle oil and processing device thereof, and application of heavy component prepared by the process

Abstract

The present application relates to the technical field of petroleum processing, in particular to a processing method of catalytic cracking light cycle oil, a processing device thereof and application of heavy components prepared by the processing method. The processing method comprises: (1) performing first distillation cutting on the catalytic cracking light cycle oil to obtain distillate oil rich in polycyclic aromatic hydrocarbons; (2) performing thermal polycondensation reaction on the distillate oil to obtain thermal polycondensation product; (3) performing second distillation cutting on the thermal polycondensation product to obtain light components and heavy components; in the distillate oil, the content of saturated hydrocarbons is ≤20 wt%, the content of monocyclic aromatic hydrocarbons is ≤10 wt%, and the content of polycyclic aromatic hydrocarbons is ≥70 wt%. The heavy components prepared by the processing method are used as raw materials of needle coke to produce needle coke, and the needle coke has the advantages of low sulfur and nitrogen content, low ash content, high true density and low thermal expansion coefficient, and meets the standard of GB / T 37308-2019 oil-based needle coke.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of petroleum processing, in particular to a processing method of catalytically cracked light cycle oil, a processing device of catalytically cracked light cycle oil, an application of a heavy component prepared by the processing method, acicular coke and an application thereof. BACKGROUND

[0002] Catalytically cracked light cycle oil (catalytically cracked light diesel oil, referred to as LCO) is usually used as a poor-quality diesel blending component mixed with straight-run diesel. From the composition of LCO, the sulfur and nitrogen contents are high, the total aromatic hydrocarbon content is high, and the cetane number is low, which is a relatively poor diesel component.

[0003] At present, the main outlets of LCO include blending components of commercial diesel, production of light aromatic hydrocarbons (BTX) or high-octane gasoline, and marine fuel oil. Hydrofining technology can greatly upgrade catalytically cracked diesel oil, and catalytically cracked diesel oil after hydro-upgrading can be used as a blending component of commercial diesel and low-sulfur marine fuel. At present, catalytically cracked diesel oil accounts for about 30% of the total amount of diesel products in China. In recent years, with the economic development of China, the growth rate of diesel demand is significantly lower than that of gasoline demand in the domestic market. The apparent consumption ratio of diesel to gasoline in China has decreased from 2.31 in 2005 to 1.25 in 2018, and the consumption ratio of diesel to gasoline will continue to show a downward trend in the coming years. LCO can be converted into light aromatic hydrocarbons or high-octane gasoline by hydro-saturation and catalytic cracking. Domestic and foreign scholars have carried out a large amount of basic research and industrial practice on this technical route.

[0004] CN201210410162.3, CN201310516588.1, CN201310517650.9, CN201310517666.X and CN201310010219.5 disclose a series of processes or methods for catalytic conversion and upgrading of catalytically cracked diesel oil. The technology for converting poor-quality LCO into high-octane catalytically cracked gasoline or light aromatic hydrocarbons (BTX) is mainly through the combination of hydrogenation and catalytic cracking. The aromatic hydrocarbons in the LCO fraction are first selectively hydrogenated and saturated, and then selectively catalytically cracked. By setting a hydrogenated LCO conversion zone and optimizing the process parameters of hydrogenation and catalytic cracking, high-octane gasoline or light aromatic hydrocarbons can be maximally produced.

[0005] Needle coke is a carbon material with silver-gray appearance and needle-shaped texture on the surface, which has high crystallinity, small thermal expansion coefficient, good orientation, good electrical conductivity and thermal conductivity, etc. It is a raw material for preparing high-end carbon material products such as high-power graphite electrode and high-performance lithium negative electrode. Needle coke can be divided into oil-based needle coke and coal-based needle coke. Oil-based needle coke has less porosity, high bulk density, high mechanical strength, low nitrogen content, low gas expansion rate during graphitization, good adsorption performance for binders and is easy to form. Although the raw materials of coal-based needle coke and oil-based needle coke are different, the existing needle coke preparation or production related technologies are all based on three to six ring polycyclic aromatic hydrocarbons as raw materials, which are prepared through heat polycondensation, mesophase culture and needle coke solidification processes.

[0006] In the past two years, affected by the strong demand for needle coke, the number of new needle coke enterprises has increased significantly. From 2018 to 2021, only four years, the production capacity increased from 510,000 tons to 2,100,000 tons, and the market competition was fierce. However, the supply of oil-based needle coke raw material catalytic slurry has not increased, resulting in an increase in the price of catalytic slurry. At the same time, due to the shortage of raw materials and poor quality of raw materials, the operating rate of some enterprises is low and the product quality is poor. That is, the domestic oil refining industry is facing the problems of LCO two and three ring aromatic hydrocarbon surplus and needle coke three to six ring aromatic hydrocarbon raw material shortage. If the aromatic components of LCO can be effectively utilized, the two and three ring aromatic hydrocarbons can be converted into three to six ring aromatic hydrocarbons, and then the needle coke and other high-end carbon materials can be produced, which will find a new way out for the efficient utilization of catalytic cracking diesel. SUMMARY

[0007] The purpose of the present application is to overcome the problems that the existing LCO is used as a raw material to prepare three to six ring aromatic hydrocarbons for the purpose of producing clean diesel, low-sulfur ship fuel, increasing light aromatic hydrocarbons or high-octane gasoline, and the technology for ultimately preparing carbon materials still has deficiencies, and to provide a processing method of catalytic cracking light cycle oil, a processing device of catalytic cracking light cycle oil, an application of the heavy component prepared by the processing method, and a needle coke and its application. The method uses catalytic cracking light cycle oil as a raw material, and the heavy component obtained can be used as a carbon material raw material, especially a needle coke raw material.

[0008] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a processing method of catalytic cracking light cycle oil, which comprises the following steps:

[0009] (1) performing first distillation cutting on the catalytic cracking light cycle oil to obtain a distillate oil rich in polycyclic aromatic hydrocarbons;

[0010] (2) performing heat polycondensation reaction on the distillate oil to obtain a heat polycondensation product;

[0011] (3) performing second distillation cutting on the heat polycondensation product to obtain a light component and a heavy component;

[0012] Among the distillate oil, the saturated hydrocarbon content is ≤20wt%, the monocyclic aromatic hydrocarbon content is ≤10wt%, and the polycyclic aromatic hydrocarbon content is ≥70wt%.

[0013] The second aspect of the present application provides a processing device for catalytic cracking light cycle oil, which comprises a first fractionating column, a thermal polycondensation reactor and a second fractionating column connected in sequence.

[0014] The first fractionating column is used for first distillation cutting of the catalytic cracking light cycle oil, and a distillate oil rich in polycyclic aromatic hydrocarbons is obtained at the bottom of the column.

[0015] The thermal polycondensation reactor is used for thermal polycondensation reaction of the distillate oil, and a thermal polycondensation product is obtained at the bottom of the column.

[0016] The second fractionating column is used for second distillation cutting of the thermal polycondensation product, and light components are obtained at the top of the column, and heavy components are obtained at the bottom of the column.

[0017] The third aspect of the present application provides an application of the heavy components prepared by the processing method of the first aspect in carbon material raw materials, preferably in needle coke raw materials.

[0018] The fourth aspect of the present application provides a needle coke, which is obtained by calcination and graphitization treatment of the heavy components prepared by the processing method of the first aspect as needle coke raw materials.

[0019] The fifth aspect of the present application provides an application of the needle coke of the fourth aspect in lithium ion battery negative materials and graphite electrodes.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] (1) The processing method provided by the present application uses catalytic cracking light cycle oil as raw material, adopts the technical means of first distillation cutting, thermal polycondensation reaction and second distillation cutting, and prepares heavy components rich in three to six ring condensed aromatic hydrocarbons, especially by adjusting the cutting temperature of the first distillation cutting, the temperature and time of the thermal polycondensation reaction, and the cutting temperature of the second distillation cutting, the yield of the heavy components can be effectively improved, and the content of three to six ring condensed aromatic hydrocarbons in the heavy components can be improved.

[0022] (2) The processing method provided by the present application enriches the source of carbon material raw materials, especially the source of needle coke raw materials, and on the other hand, it also widens the resource utilization of catalytic cracking cycle oil, and improves the added value of the product.

[0023] (3) The heavy component prepared by the processing method provided by the application is used as a needle coke raw material to produce needle coke, and the produced needle coke has the advantages of low sulfur and nitrogen content, low ash content, high true density, and low thermal expansion coefficient, and meets the GB / T 37308-2019 oil-based needle coke standard; at the same time, the needle coke is used for lithium ion batteries, which can effectively improve the electrochemical performance of the lithium ion batteries. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a processing device for catalytically cracked light cycle oil provided by the application;

[0025] Figure 2a and Figure 2b are a 200-fold and a 500-fold polarizing micrograph of the needle coke P2 prepared from the heavy component of Example 2, respectively.

[0026] REFERENCE SIGNS

[0027] I, first fractionating column II, thermal polycondensation reactor III, second fractionating column 01, catalytically cracked light cycle oil 02, distillate oil 03, light fraction

[0028] 04, thermal polycondensation product 05, cracking gas 06, heavy component 07, light component DETAILED DESCRIPTION

[0029] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and the values are approximate values and should be understood as including values approximately near to the stated values. For ranges, the endpoints are included between the values of each range, between the endpoints of each range and between each individual point value, and new ranges can be created by combining the endpoints and individual point values with one another, which should be considered as specifically disclosed herein.

[0030] In the present application, without special circumstances, “first” and “second” do not represent the order of precedence, nor do they limit each material or step, but are only used to distinguish or indicate that they are not the same material or step. For example, “first” and “second” in “first distillation cut” and “second distillation cut” are only used to indicate that they are not the same distillation cut.

[0031] The first aspect of the present application provides a processing method for catalytically cracked light cycle oil, which comprises the following steps:

[0032] (1) The catalytically cracked light cycle oil is subjected to first distillation cut to obtain distillate oil rich in polycyclic aromatic hydrocarbons;

[0033] (2) The distillate oil is subjected to thermal polycondensation reaction to obtain thermal polycondensation product;

[0034] (3) subjecting the thermal polycondensation product to a second distillation cut to obtain a light component and a heavy component;

[0035] In the distillate oil, the saturated hydrocarbon content is ≤20wt%, the monocyclic aromatic hydrocarbon content is ≤10wt%, and the polycyclic aromatic hydrocarbon content is ≥75wt%.

[0036] The inventors of the present application have found that, by using the technical means of first distillation cut, thermal polycondensation reaction and second distillation cut, the heavy component obtained by using the catalytically cracked light cycle oil as the raw material can be used as the needle coke raw material. In particular, by adjusting the parameters of the raw material, the initial boiling point of the distillate oil, and the temperature of the thermal polycondensation reaction, the content of each component in the thermal polycondensation product is adjusted, so that the yield of the heavy component is adjusted.

[0037] In the present application, unless otherwise specified, the catalytically cracked light cycle oil refers to the diesel oil fraction produced by catalytic cracking, and the distillation range is 180-380℃.

[0038] In the present application, unless otherwise specified, in the distillate oil, the saturated hydrocarbon content refers to the sum of the content of paraffin and naphthene; and the polycyclic aromatic hydrocarbon content refers to the sum of the content of diaromatic hydrocarbon and triaromatic hydrocarbon.

[0039] In some embodiments of the present application, preferably, in step (1), the saturated hydrocarbon content in the distillate oil is 0.1-15wt%, the monocyclic aromatic hydrocarbon content is 0.1-10wt%, and the polycyclic aromatic hydrocarbon content is 75-99.8wt%.

[0040] In some embodiments of the present application, preferably, in the distillate oil, the diaromatic hydrocarbon content accounts for ≥75% of the polycyclic aromatic hydrocarbon content, preferably 79-99%; and the triaromatic hydrocarbon content accounts for ≤25% of the polycyclic aromatic hydrocarbon content, preferably 1-21%. By using the preferred conditions, the yield of the heavy component and the content of tri- to hexaromatic hydrocarbons in the heavy component can be further improved.

[0041] In some embodiments of the present application, preferably, in step (1), the physical property parameters of the catalytically cracked light cycle oil satisfy: the sulfur content is 0.1-4wt%, the nitrogen content is 1-1000mg / kg, the oxygen content is 1-1000mg / kg, and the total aromatic hydrocarbon content is 50-90wt%. In the present application, unless otherwise specified, the total aromatic hydrocarbon content in the catalytically cracked light cycle oil refers to the sum of the content of monocyclic aromatic hydrocarbon, diaromatic hydrocarbon and triaromatic hydrocarbon.

[0042] In the present application, unless otherwise specified, the hydrocarbon composition in the raw oil is determined according to the "Determination of Hydrocarbons in the Saturated Hydrocarbon Fraction of Gas Oil (Mass Spectrometry) (SH / T 0659-1998)".

[0043] In the present application, unless otherwise specified, the hydrocarbon composition in the distillate oil is determined according to the Determination of Hydrocarbon Composition in Middle Distillate (Mass Spectrometry) (SH / T 0606-2019).

[0044] In the present application, unless otherwise specified, the carbon and hydrogen element content parameters are determined according to the Determination of Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants by Elemental Analyzer Method (SH / T 0656-2017).

[0045] In the present application, unless otherwise specified, the oxygen content parameter is determined according to the Determination of Total Oxygen Content in Gasoline, Diesel and Methanol Fuels by Reductive Cracking Method (SH / T 0986-2019).

[0046] In the present application, unless otherwise specified, the nitrogen content parameter is determined according to the Determination of Nitrogen Content in Petroleum and Petroleum Products by Boat Injection Chemical Luminescence Method (SH / T 0704-2010).

[0047] In the present application, unless otherwise specified, the sulfur content parameter is determined according to the Determination of Sulfur Content in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence (GB / T 17040-2008).

[0048] In some embodiments of the present application, preferably, the content of monocyclic aromatic hydrocarbons in the catalytically cracked light cycle oil is ≥5 wt%, preferably 5-15 wt%; the content of bicyclic aromatic hydrocarbons is ≥50 wt%, preferably 50-80 wt%; and the content of tricyclic aromatic hydrocarbons is ≥5 wt%, preferably 5-10 wt%.

[0049] In the present application, the type of the catalytically cracked light cycle oil has a wide selection range as long as the catalytically cracked light cycle oil meets the above limitations. Preferably, the catalytically cracked light cycle oil is selected from catalytically cracked middle distillate oil and / or catalytically cracked refined diesel.

[0050] In a specific embodiment of the present application, preferably, the catalytically cracked middle distillate oil is selected from at least one of a residue catalytically cracked distillate oil, a wax oil catalytically cracked distillate oil and a heavy oil catalytically cracked distillate oil. That is, the catalytically cracked middle distillate oil is a middle distillate oil produced by a catalytic cracking unit, wherein the catalytic cracking unit can be a residue catalytic cracking unit, a wax oil catalytic cracking unit, a heavy oil catalytic cracking unit and a mixed feedstock catalytic cracking unit.

[0051] In the present application, unless otherwise specified, the catalytically cracked refined diesel refers to a refined catalytic diesel oil with low sulfur content and low nitrogen content obtained by hydrotreating and hydrofining of the catalytically cracked middle distillate oil.

[0052] In the present application, the first distillation cut is intended to obtain the distillate oil of a specific fraction. Preferably, the cut temperature of the first distillation cut is 220-300°C, such as 220°C, 230°C, 240°C, 250°C, 260°C, 280°C, 300°C, and any value in the range between any two of these values, preferably 230-280°C. With the preferred conditions, it is more advantageous to control the content of saturated hydrocarbons, monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons in the distillate oil, and further control the yield of heavy components and the content of three to six ring aromatic hydrocarbons in the heavy components.

[0053] In some embodiments of the present application, preferably, in step (1), the initial boiling point of the distillate oil is 220-300°C, such as 220°C, 230°C, 240°C, 250°C, 260°C, 280°C, 300°C, and any value in the range between any two of these values, preferably 230-280°C. In the present application, the final boiling point of the distillate oil is not limited, and the final boiling point of the distillate oil is the final boiling point of the raw oil.

[0054] In the present application, the thermal polycondensation reaction is intended to polycondense the polycyclic aromatic hydrocarbons (i.e. diaromatic hydrocarbons and triaromatic hydrocarbons) of the distillate oil into three to six ring aromatic hydrocarbons. Preferably, in step (2), the conditions of the thermal polycondensation reaction include: the temperature is 400-510°C, such as 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 480°C, 510°C, and any value in the range between any two of these values, preferably 410-460°C; the time is 0.1-5h, such as 0.1h, 0.5h, 1h, 2h, 3h, 5h, and any value in the range between any two of these values, preferably 0.5-3h.

[0055] In some embodiments of the present application, preferably, the content of toluene insoluble in the thermal polycondensation product is ≤5wt%, such as 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, and any value in the range between any two of these values, preferably ≤2wt%.

[0056] In some embodiments of the present application, preferably, the content of total aromatic hydrocarbons in the thermal polycondensation product is 90-99wt%, and the content of diaromatic hydrocarbons is ≤5wt%. In the present application, the total aromatic hydrocarbons in the thermal polycondensation product refer to the sum of the contents of monocyclic aromatic hydrocarbons, diaromatic hydrocarbons, triaromatic hydrocarbons, tetraaromatic hydrocarbons, pentaaromatic hydrocarbons and hexaaromatic hydrocarbons.

[0057] In the present application, the second distillation cut is intended to divide the thermal polycondensation product into light components and heavy components.

[0058] In some embodiments of the present application, preferably, the initial boiling point of the heavy components is 330-400℃, for example, 300℃, 340℃, 350℃, 360℃, 380℃, 400℃, and any value within the range between any two of them, preferably 340-360℃; the final boiling point is 500-600℃, for example, 500℃, 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, and any value within the range between any two of them, preferably 550-600℃.

[0059] In some embodiments of the present application, preferably, the total content of three to six ring aromatic hydrocarbons in the heavy components is 80-95wt%.

[0060] In some embodiments of the present application, preferably, the fraction oil is heated to 400-510℃, for example, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 480℃, 510℃, and any value within the range between any two of them, preferably 410-460℃, before the thermal polycondensation reaction. In the present application, the heating method has a wide range of choices as long as the fraction oil is heated to the temperature of the thermal polycondensation reaction, including but not limited to tube furnace heating, heat exchanger heating, tube furnace heating, etc.

[0061] In some embodiments of the present application, preferably, the processing method further comprises: recycling the light components back to the catalytic cracking light cycle oil.

[0062] The second aspect of the present application provides a structural diagram of a processing device for catalytic cracking light cycle oil as shown in Figure 1 It can be seen that the processing device comprises: a first fractionating column I, a thermal polycondensation reactor II and a second fractionating column III connected in sequence; Figure 1

[0063] The first fractionating column I is used for first distillation cut of the catalytic cracking light cycle oil 01, and the fraction oil 02 rich in polycyclic aromatic hydrocarbons is obtained at the bottom of the column.

[0064] The thermal polycondensation reactor II is used for thermal polycondensation reaction of the fraction oil 02, and the thermal polycondensation product 04 is obtained at the bottom of the column.​

[0065] The second fractionating column III is used for second distillation cutting of the hot polycondensation product 04, and the light component 07 is obtained at the top, and the heavy component 06 is obtained at the bottom.

[0066] In the present application, the types of the first fractionating column and the second fractionating column have a wide range of selection, as long as the catalytic cracking light cycle oil and the hot polycondensation product are respectively subjected to the above-mentioned fraction cutting. In the present application, the first fractionating column and the second fractionating column include, but are not limited to, a vacuum fractionating column and the like.

[0067] According to the present application, as shown in Figure 1 , the top of the first fractionating column I also obtains a light fraction 03, and the top of the hot polycondensation reactor II also obtains a cracking gas 05.

[0068] According to the present application, preferably, as shown in Figure 1 , the top of the second fractionating column III is also connected with the raw material inlet of the first fractionating column I, for returning and mixing the light component 07 into the catalytic cracking light cycle oil 01 to perform the first distillation cutting.

[0069] The third aspect of the present application provides an application of the heavy component prepared by the processing method provided in the first aspect in a carbon material raw material, preferably in a needle coke raw material.

[0070] The fourth aspect of the present application provides a needle coke, which is obtained by calcining and graphitizing the heavy component prepared by the processing method provided in the first aspect as a needle coke raw material.

[0071] In some embodiments of the present application, preferably, the conditions of the calcining include: the temperature is 1300-1450℃, preferably 1350-1400℃; the time is 10-20h, preferably 12-14h.

[0072] In some embodiments of the present application, preferably, the conditions of the graphitizing treatment include: the temperature is 2700-3000℃, preferably 2800-2900℃; the time is 2-5h, preferably 3-4h.

[0073] In some embodiments of the present application, preferably, the sulfur content of the needle coke is ≤0.5wt%, the nitrogen content is ≤0.5wt%, the ash content is ≤0.1wt%, the true density (before calcining) is ≥1.35g / cm 3 , the true density (before calcining) is ≥2.12g / cm 3 , the thermal expansion coefficient (25-600℃) is ≤1.3×10 -6 / ℃, and the polarized light microstructure thereof is a wide-range flow line type.

[0074] The fifth aspect of the present application provides an application of the needle coke provided by the fourth aspect in a lithium ion battery negative material, a graphite electrode.

[0075] According to a particularly preferred embodiment of the present application, a processing method of catalytic cracking light cycle oil, the processing method comprises the following steps:

[0076] (1) The catalytic cracking light cycle oil is subjected to first distillation cutting to obtain a distillate oil rich in polycyclic aromatic hydrocarbons;

[0077] (2) The distillate oil is subjected to thermal polycondensation reaction to obtain a thermal polycondensation product;

[0078] (3) After the thermal polycondensation product is heated to 410-460℃, second distillation cutting is performed to obtain light components and heavy components;

[0079] The content of monocyclic aromatic hydrocarbons in the catalytic cracking light cycle oil is 5-15wt%; the content of bicyclic aromatic hydrocarbons is 50-80wt%; and the content of tricyclic aromatic hydrocarbons is 5-10wt%;

[0080] The content of saturated hydrocarbons in the distillate oil is 0.1-15wt%, the content of monocyclic aromatic hydrocarbons is 0.1-10wt%, and the content of polycyclic aromatic hydrocarbons is 75-99.8wt%;

[0081] The cutting temperature of the first distillation cutting is 230-280℃; the conditions of the thermal polycondensation reaction include: the temperature is 410-460℃; the time is 0.5-3h; the content of toluene insolubles in the thermal polycondensation product is ≤2wt%; the cutting temperature of the second distillation cutting is 340-360℃; and the total content of three to six ring aromatic hydrocarbons in the heavy components is 80-95wt%.

[0082] The present application will be described in detail below through examples.

[0083] The hydrocarbon composition in the raw oil is determined according to the Hydrocarbon Determination Method for Saturated Hydrocarbon Distillate in Gas Oil (Mass Spectrometry) (SH / T0659-1998);

[0084] The hydrocarbon composition in the distillate oil is determined according to the Hydrocarbon Composition Determination Method for Middle Phase Distillate (Mass Spectrometry) (SH / T0606-2019);

[0085] The carbon and hydrogen element content parameters are determined according to the Elemental Analyzer Method for Determining Carbon, Hydrogen and Nitrogen in Petroleum Products and Lubricants (SH / T 0656-2017);

[0086] The oxygen content parameter is determined according to the Reducing Cleavage Method for Determining Total Oxygen Content in Gasoline, Diesel and Methanol Fuel (SH / T0986-2019);

[0087] The nitrogen content parameter is determined according to Determination of Nitrogen Content in Petroleum and Petroleum Products - Shipboard Injection Chemical Luminescence Method (SH / T 0704-2010);

[0088] The sulfur content parameter is determined according to Determination of Sulfur Content in Petroleum and Petroleum Products - Energy Dispersive X-ray Fluorescence Method (GB / T 17040-2008).

[0089] The yield is calculated in the following manner: The component is selected from a light component or a heavy component.

[0090] Example 1

[0091] (1) The YS catalytic diesel oil (each component and content thereof are shown in Table 1) is used as a raw material to perform a first distillation cut (cut temperature is 250°C) to obtain a distillate oil A1 (each component and content thereof are shown in Table 2) with a distillation range of 250°C or more;

[0092] (2) The distillate oil A1 is heated to 410°C to perform a thermal polycondensation reaction (temperature is 410°C, time is 1.2h) to obtain a thermal polycondensation product S1 (each component and content thereof are shown in Table 3);

[0093] (3) The thermal polycondensation product S1 is subjected to a second distillation cut (cut temperature is 400°C) to obtain a light component and a heavy component, and the yields of the light component and the heavy component are shown in Table 4.

[0094] Example 2

[0095] (1) The YS catalytic diesel oil (each component and content thereof are shown in Table 1) is used as a raw material to perform a first distillation cut (cut temperature is 280°C) to obtain a distillate oil A2 (each component and content thereof are shown in Table 2) with a distillation range of 280°C or more;

[0096] (2) The distillate oil A2 is heated to 440°C to perform a thermal polycondensation reaction (temperature is 440°C, time is 1.2h) to obtain a thermal polycondensation product S2 (each component and content thereof are shown in Table 3);

[0097] (3) The thermal polycondensation product S2 is subjected to a second distillation cut (cut temperature is 400°C) to obtain a light component and a heavy component, and the yields of the light component and the heavy component are shown in Table 4.

[0098] Example 3

[0099] (1) The YS catalytic diesel oil (each component and content thereof are shown in Table 1) is used as a raw material to perform a first distillation cut (cut temperature is 280°C) to obtain a distillate oil A2 (each component and content thereof are shown in Table 2) with a distillation range of 280°C or more;

[0100] (2) The distillate oil A2 was heated to 410°C, and a thermal polycondensation reaction was performed (temperature: 410°C, time: 1.2 h) to obtain a thermal polycondensation product S3 (see Table 3 for components and contents thereof).

[0101] (3) The thermal polycondensation product S3 was subjected to a second distillation cut (cut temperature: 400°C) to obtain light and heavy components, and the yields of the light and heavy components are shown in Table 4.

[0102] Example 4

[0103] The method of Example 1 was followed, except that

[0104] In step (1), the YS catalytic diesel was replaced by MM catalytic diesel, the first distillation cut temperature was replaced by 280°C, and the other conditions were the same, to obtain a distillate oil A3 having a distillation range of 280°C or higher (see Table 2 for components and contents thereof).

[0105] In step (2), a thermal polycondensation product S4 was obtained (see Table 3 for components and contents thereof).

[0106] In step (3), the light and heavy components were obtained, and the yields of the light and heavy components are shown in Table 4.

[0107] Example 5

[0108] The method of Example 1 was followed, except that

[0109] In step (1), the first distillation cut temperature was adjusted to 300°C to obtain a distillate oil A4 having a distillation range of 300°C or higher.

[0110] In step (2), a thermal polycondensation product S5 was obtained (see Table 3 for components and contents thereof).

[0111] In step (3), the light and heavy components were obtained, and the yields of the light and heavy components are shown in Table 4.

[0112] Example 6

[0113] The method of Example 1 was followed, except that

[0114] In step (1), the first distillation cut temperature was adjusted, and the other conditions were the same, to obtain a distillate oil A5 having a distillation range of 200°C (see Table 2 for components and contents thereof).

[0115] In step (2), a thermal polycondensation product S6 was obtained (see Table 3 for components and contents thereof).

[0116] In step (3), the light and heavy components were obtained, and the yields of the light and heavy components are shown in Table 4.

[0117] Example 7

[0118] The method of Example 1 was followed, except that​​​​​​​​​​​​The procedure of Example 1 was followed except that in Step (1),

[0119] In Step (2), the above distillate oil was heated to 520°C and subjected to thermal polycondensation reaction (temperature: 520°C, time: 1.2 h), with the other conditions being the same, to obtain a thermal polycondensation product S7 (see Table 3 for the components and their contents).

[0120] In Step (3), the yields of the light component and the heavy component are both listed in Table 4.

[0121] Example 8

[0122] The procedure of Example 1 was followed except that in Step (1),

[0123] In Step (3), the cut temperature of the second distillation was replaced with 450°C, with the other conditions being the same, to obtain the yields of the light component and the heavy component, both of which are listed in Table 4.

[0124] Comparative Example 1

[0125] The procedure of Example 1 was followed except that there was no Step (1), i.e.,

[0126] The YS catalytic diesel oil was directly heated to 440°C and subjected to thermal polycondensation reaction (temperature: 440°C, time: 1 h) to obtain a thermal polycondensation product DS1 (see Table 3 for the components and their contents).

[0127] The above thermal polycondensation product DS1 was subjected to the second distillation cut (cut temperature: 400°C) to obtain the yields of the light component and the heavy component, both of which are listed in Table 4.

[0128] Comparative Example 2

[0129] The procedure of Example 1 was followed except that in Step (1),

[0130] In Step (1), the YS catalytic diesel oil was replaced with YS straight-run diesel oil (see Table 1 for the components and their contents), with the other conditions being the same, to obtain a distillate oil DA1 having a distillation range of 280°C (see Table 2 for the components and their contents) ;

[0131] In Step (2), a thermal polycondensation product DS2 was obtained (see Table 3 for the components and their contents).

[0132] In Step (3), the yields of the light component and the heavy component are both listed in Table 4.

[0133] Table 1

[0134]

[0135]

[0136] Table 2

[0137]

[0138] Table 3

[0139]

[0140]

[0141] Table 3 (continued)

[0142]

[0143] Table 4

[0144]

[0145]

[0146] Table 4 (continued)

[0147] Yield, wt% Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Light component yield 80 76 78 95 98 Heavy component yield 20 24 22 5 2 Total yield 100 100 100 100 100

[0148] As can be seen from the results of Tables 1-4, compared with Comparative Examples 1-2, the heavy components rich in three to six ring condensed aromatic hydrocarbons are obtained and the yield of the heavy components is effectively improved by using catalytic cracking light cycle oil as the raw oil, and using the technical means of first distillation cutting, thermal polycondensation reaction and second distillation cutting in Examples 1-8.

[0149] Test Example

[0150] The heavy components obtained in Examples 1-8 and Comparative Examples 1-2 were respectively used as needle coke raw materials (P1-P8 and DP1-DP2) to successively perform calcination (temperature 1350℃, time 4h) and graphitization treatment (temperature 2800℃, time 2h), and the physical property parameters of the needle coke (W1-W7 and DW1-DW3) obtained were all listed in Table 5.

[0151] Among them, the polarizing micrographs of the needle coke P2 obtained from the heavy component of Example 2 at 200 times and 500 times are shown in Figure 2a and Figure 2b As shown in Figure 2a and Figure 2b The polarizing microstructure of the needle coke P2 is wide area streamline type.

[0152] Table 5

[0153]

[0154]

[0155] Table 5 (continued)

[0156]

[0157] As can be seen from the results in Table 5, compared with Comparative Example 1-2, the needle coke prepared by the processing method provided by the present application in Example 1-8 has the advantages of low sulfur and nitrogen content, low ash content, high true density and low thermal expansion coefficient, and meets the standard of GB / T37308-2019 oil-based needle coke.

[0158] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A process for the processing of catalytically cracked light cycle oil, characterized in that, The processing method comprises the following steps: (1) subjecting catalytic cracking light cycle oil to first distillation cutting to obtain a distillate oil rich in polycyclic aromatic hydrocarbons; (2) subjecting the distillate oil to thermal polycondensation reaction to obtain a thermal polycondensation product; the thermal polycondensation reaction conditions comprise: temperature of 410-460℃; time of 0.5-3h; (3) subjecting the thermal polycondensation product to second distillation cutting to obtain light components and heavy components; the cutting temperature of the second distillation cutting is 340-400℃; wherein, in the distillate oil, the saturated hydrocarbon content is ≤20wt%, the monocyclic aromatic hydrocarbon content is ≤10wt%, and the polycyclic aromatic hydrocarbon content is ≥70wt%; the polycyclic aromatic hydrocarbon content is the sum of the diaromatic hydrocarbon content and the triaromatic hydrocarbon content; wherein, the physical property parameters of the catalytic cracking light cycle oil satisfy: sulfur content of 0.1-4wt%; nitrogen content of 1-1000mg / kg; oxygen content of 1-1000mg / kg; total aromatic hydrocarbon content of 50-90wt%; wherein, the total content of tri- to hexacyclic aromatic hydrocarbons in the heavy components is 80-95wt%.

2. The method of processing according to claim 1, wherein, In step (1), the saturated hydrocarbon content in the distillate oil is 0.1-15wt%, the monocyclic aromatic hydrocarbon content is 0.1-10wt%, and the polycyclic aromatic hydrocarbon content is 75-99.8wt%; and / or, the diaromatic hydrocarbon content accounts for ≥75% of the polycyclic aromatic hydrocarbon content; the triaromatic hydrocarbon content accounts for ≤25% of the polycyclic aromatic hydrocarbon content.

3. The method of processing according to claim 2, wherein, In step (1), the diaromatic hydrocarbon content accounts for 79-99% of the polycyclic aromatic hydrocarbon content; the triaromatic hydrocarbon content accounts for 1-21% of the polycyclic aromatic hydrocarbon content.

4. The method of processing according to claim 1, wherein, In step (1), the content of monocyclic aromatic hydrocarbons in the catalytic cracking light cycle oil is ≥5wt%; the content of diaromatic hydrocarbons is ≥50wt%; the content of triaromatic hydrocarbons is ≥5wt%; and / or, the catalytic cracking light cycle oil is selected from catalytic cracking middle distillate oil and / or catalytic cracking refined diesel.

5. The method of processing according to claim 4, wherein, In step (1), the content of monocyclic aromatic hydrocarbons in the catalytic cracking light cycle oil is 5-15wt%; the content of diaromatic hydrocarbons is 50-80wt%; the content of triaromatic hydrocarbons is 5-10wt%; and / or, the catalytic cracking middle distillate oil is selected from at least one of wax oil catalytic cracking middle distillate oil and heavy oil catalytic cracking middle distillate oil, and the heavy oil catalytic cracking middle distillate oil is selected from residual oil catalytic cracking middle distillate oil.

6. The method of processing according to claim 1, wherein, In step (1), the cutting temperature of the first distillation cutting is 220-300℃; and / or, the initial boiling point of the distillate oil is 220-300℃.

7. The method of processing according to claim 6, wherein, In step (1), the cutting temperature of the first distillation cutting is 230-280℃; and / or, the initial boiling point of the distillate oil is 230-280℃.

8. The method of processing according to claim 1, wherein, In step (2), the toluene insoluble content in the thermal polycondensation product is ≤5wt%; and / or, the total aromatic hydrocarbon content in the thermal polycondensation product is 90-99wt%, and the diaromatic hydrocarbon content is ≤5wt%.

9. The method of processing according to claim 8, wherein, In step (2), the toluene insoluble content in the thermal polycondensation product is ≤2wt%.

10. The method of processing according to any one of claims 1-9, wherein, In step (3), the initial boiling point of the heavy components is 340-400℃; the final boiling point is 500-600℃; And / or, the processing method further comprises: heating the distillate oil to 400-510 ℃ before the thermal polycondensation reaction.

11. The method of processing according to claim 10, wherein, In step (3), the cutting temperature of the second distillation cutting is 340-360 ℃; And / or, the initial boiling point of the heavy component is 340-360 ℃; The final boiling point is 550-600 ℃; And / or, the processing method further comprises: heating the distillate oil to 410-460 ℃ before the thermal polycondensation reaction.

12. Needle coke, characterized in that The needle coke is obtained by calcining and graphitizing the heavy component obtained by the processing method of any one of claims 1-11 as the needle coke raw material; Wherein, the polarized light microscopic structure of the needle coke is a wide area streamline type. The sulfur content of the needle coke is less than or equal to 0.5 wt%, the nitrogen content is less than or equal to 0.5 wt%, the ash content is less than or equal to 0.1 wt%, the true density before calcination is greater than or equal to 1.35 g / cm 3 , the true density after calcination is greater than or equal to 2.12 g / cm 3 , and the thermal expansion coefficient at 25-600 DEG C is less than or equal to 1.3 x 10 -6 / DEG C.

13. The needle coke of claim 12 is used in lithium ion battery negative materials and / or graphite electrodes.

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