A mixed processing method for inferior heavy oil and hydrocracking tail oil

Abstract

The present invention relates to the field of petrochemicals and discloses a mixed processing method for inferior heavy oil and hydrocracking tail oil, comprising: A) subjecting the inferior heavy oil to a slurry bed hydrogenation reaction, and distilling the product to obtain fractions A-D with boiling points <210°C, 210-220°C, 220-550°C, and >550°C; B) cooling and separating fraction B to obtain crude naphthalene and a post-naphthalene fraction; and subjecting the post-naphthalene fraction to a hydrorefining reaction together with fraction A, fraction C, and hydrocracking tail oil; and C) subjecting the resulting liquid product to a hydrocracking reaction, and separating the resulting product to obtain C1-C4 fuel gas, BTX mixed triphenyls, and a fraction E with a boiling point >165°C. The present invention utilizes the differences in composition between the inferior heavy oil and the hydrocracking tail oil to a series of reactions and separations, ultimately efficiently converting the inferior heavy oil and the hydrocracking tail oil into three high-value-added products: fuel gas, crude naphthalene, and BTX, thereby contributing to low-carbon emission reduction and improving enterprise economic efficiency.

Description

Technical Field

[0001] The present invention relates to the field of petrochemicals, and in particular to a method for mixing and processing inferior heavy oil and hydrocracking tail oil. Background Art

[0002] The scarcity and non-renewable nature of oil resources, coupled with the gradual replacement of power energy with alternative energy sources, has led to a new trend in the petrochemical industry: converting oil resources into fine chemical feedstocks or fine chemicals. Therefore, converting low-quality heavy oils such as ethylene tar and catalytic slurry into high-value-added fine chemicals or their feedstocks is of great practical significance.

[0003] Ethylene tar is a byproduct of ethylene cracking units in the petrochemical industry and belongs to the heavy fraction range. Currently, ethylene tar is primarily sold as heavy fuel oil or carbon black feedstock. Patents CN1970688A and CN106883871B disclose methods, and some companies have also developed comprehensive methods for the utilization of ethylene tar.

[0004] Hydrocracking tail oil is a byproduct of the hydrocracking unit. The primary conversion rate of the hydrocracking process is typically 60-90%, leaving 10-40% of unconverted products, known as hydrocracking tail oil. Overseas, hydrocracking tail oil is used to produce lubricant base oils, such as Mobil's MLDW process and British Petroleum's BP process. Currently, domestic companies such as Jinling Petrochemical Company's Nanjing Refinery use a tandem hydrodegassing and hydrorefining process to produce VHVI-100 base oil. Maoming Refinery uses solvent dewaxing and clay refining on hydrocracking tail oil to produce transformer oil, turbine oil, hydraulic oil, and other products. Some companies also use urea dewaxing to produce transformer oil and liquid petroleum, or to produce white oil, which is used as a feedstock for ethylene crackers and catalytic cracking units. Summary of the Invention

[0005] To address the above technical problems, the present invention provides a method for processing low-quality heavy oil and hydrocracking tail oil. This method utilizes the differences in composition between the low-quality heavy oil and hydrocracking tail oil to efficiently convert them into three high-value-added products: fuel gas, crude naphthalene, and BTX through a series of reactions and separations, including slurry bed hydrogenation, hydrorefining, and hydrocracking.

[0006] The specific technical solution of the present invention is: a mixed processing method of inferior heavy oil and hydrocracking tail oil, characterized by comprising:

[0007] A) Low-quality heavy oil is reacted in a slurry bed hydrogenation reactor. The hydrogenated products are distilled to obtain fraction A with a boiling point of less than 210°C, fraction B with a boiling point of 210-220°C, fraction C with a boiling point of 220-550°C, and fraction D with a boiling point of more than 550°C; fraction D is recycled to the slurry bed hydrogenation reactor for further reaction.

[0008] B) Fraction B is cooled and separated to obtain crude naphthalene and a naphthalene fraction; the naphthalene fraction, fraction A, fraction C and hydrocracking tail oil are fed into a hydrotreating reactor for reaction.

[0009] C) Separating the obtained products to separate H2S and NH3, and the liquid phase products after separation enter the hydrocracking reactor for reaction, and the obtained products are separated to obtain C1-C4 fuel gas, BTX mixed triphenyls and fraction E with a boiling point greater than 165°C; fraction E is recycled to the hydrocracking reactor for further reaction.

[0010] D) collecting the obtained C1-C4 fuel gas, crude naphthalene, BTX and mixed triphenyls.

[0011] The present invention utilizes the difference in composition between inferior heavy oil and hydrocracking tail oil, first after the former is carried out slurry bed hydrogenation reaction, makes the first preliminary hydrogenation saturation of low value-added condensed ring aromatics, obtains more dicyclic aromatics;Adopt distillation, cooling separation mode to obtain high value-added crude naphthalene afterwards, then will remove other fractions (naphthalene rear fraction and fraction A, fraction C) of unconverted oil;Wherein, naphthalene rear fraction comprises the various hydrocarbons of boiling point corresponding to this boiling range, such as alkane, cycloalkanes, the aromatics removing naphthalene, also comprises a small amount of naphthalene not separated completely etc.) together with hydrocracking tail oil, carry out hydrorefining reaction, hydrocracking reaction successively, finally obtain high value-added BTX mixed triphenyl and C1-C4 fuel gas product.To sum up, the inventive method efficiently utilizes the refining by-product of low value-added, can significantly improve the economic benefit of refining enterprise.

[0012] Preferably, the inferior heavy oil includes ethylene tar, vacuum residue, catalytic slurry oil, coal tar, etc. Ethylene tar is a by-product of naphtha steam cracking to ethylene units in refineries, also known as ethylene cracking oil; and the hydrocracking tail oil is the heavy fraction obtained by separating the fixed-bed hydrocracking products.

[0013] Preferably, the mass ratio of the inferior heavy oil to the hydrocracking tail oil is (0.8-1.2):1.

[0014] The present invention optimizes the aforementioned ratio by initially examining the hydrocarbon composition and content of each component of low-quality heavy oil and hydrocracking tail oil. This ratio ensures that the hydrocarbon types corresponding to each carbon number in the mixed feed to the hydrotreating reactor are approximately the same, and the carbon numbers of different hydrocarbons are relatively continuous. Otherwise, if this ratio is too high or too low, the content of hydrocarbon compounds with a certain carbon number may be significantly higher, which will lead to more pronounced concentrated heat release in the hydrotreating reaction, which is very detrimental to the smooth operation of the reactor and can easily lead to adverse consequences such as overloading the cold hydrogen compressor and sintering of the catalyst, resulting in permanent deactivation.

[0015] Preferably, in step A), the slurry bed hydrogenation reactor is filled with a regenerated slurry bed hydrogenation catalyst.

[0016] Preferably, in step A), in a slurry bed hydrogenation reactor, low-quality heavy oil, sulfur powder and a regenerated slurry bed hydrogenation catalyst are mixed to form a slurry hydrogenation bed, and the hydrogenation reaction is carried out in an atmosphere containing hydrogen.

[0017] Preferably, in step A), the regenerated slurry bed hydrogenation catalyst accounts for 0.05%-0.1 wt% of the low-quality heavy oil and 80-100 wt% of the sulfur powder.

[0018] Preferably, in step A), the reaction conditions of the slurry bed hydrogenation reactor are: reaction pressure 16-20 MPa, reaction temperature 420-460°C, liquid hourly space velocity 1.0-3.0 h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

[0019] Preferably, in step B), the hydrotreating reactor is sequentially filled with a hydroprotection catalyst and a hydrotreating catalyst in a volume ratio of 1:2-4 from top to bottom.

[0020] Preferably, in step B), the cooling separation conditions of the fraction B are: pressure 0.08-0.12 MPa, cooling temperature 20-30°C.

[0021] Preferably, in step B), the reaction conditions of the hydrotreating reactor are: reaction pressure 11-15 MPa, reaction temperature 360-380°C, hourly space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

[0022] Preferably, in step C), the hydrocracking reactor is filled with a hydrocracking catalyst and a naphthalene hydro-reforming catalyst in a ratio of 2-4:1 from top to bottom.

[0023] Preferably, the naphthalene hydrogenation catalyst is the catalyst specified in CN112275310B of Ningbo Zhongjin Petrochemical Co., Ltd.

[0024] The present invention creatively grades a naphthalene-selective naphthalene hydro-reforming catalyst in a hydrocracking reactor, so that heavy aromatic compounds after the hydrocracking reaction are selectively hydrogenated and reformed into benzene compounds rather than completely reacting into cyclohexane compounds. This can effectively increase the yield of BTX mixed triphenyls and is beneficial to improving the added value rate of raw materials per ton.

[0025] Preferably, in step C), the reaction conditions of the hydrocracking reactor are: reaction pressure 11-15 MPa, reaction temperature 370-390°C, liquid hourly space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention utilizes the difference in composition between inferior heavy oil and hydrocracking tail oil, and through a series of reactions and separations such as slurry bed hydrogenation, hydrorefining, and hydrocracking, the inferior heavy oil and hydrocracking tail oil are ultimately efficiently converted into three high-value-added products: fuel gas, crude naphthalene, and BTX, which is beneficial to low-carbon emission reduction and improving the economic efficiency of the enterprise.

[0028] (2) The present invention uses waste fixed-bed hydrogenation catalyst as the main component and iron powder as the auxiliary component, and obtains a regenerated slurry bed hydrogenation catalyst after impregnation with mercaptan polyoxyethylene ether. The catalyst not only has the advantages of simple process, low cost, low carbon and environmental protection, but also has excellent activity. A good catalytic hydrogenation effect can be achieved with a relatively small catalyst dosage (0.05%-0.1%).

[0029] (3) The present invention uses a naphthalene-selective naphthalene hydro-reforming catalyst in the hydrocracking reactor, so that the heavy aromatic compounds after the hydrocracking reaction are selectively hydrogenated and reformed into benzene compounds instead of completely reacting into cyclohexane compounds, which can effectively improve the BTX mixed triphenyl yield. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the embodiments.

[0031] Overall embodiment

[0032] A mixed processing method for inferior heavy oil and hydrocracking tail oil comprises:

[0033] A) Low-quality heavy oil is reacted in a slurry bed hydrogenation reactor. The hydrogenated products are distilled to obtain fraction A with a boiling point of less than 210°C, fraction B with a boiling point of 210-220°C, fraction C with a boiling point of 220-550°C, and fraction D with a boiling point of more than 550°C; fraction D is recycled to the slurry bed hydrogenation reactor for further reaction.

[0034] Preferably, the inferior heavy oil includes ethylene tar, vacuum residue, catalytic oil slurry, coal tar, etc.; ethylene tar is a by-product of the naphtha steam cracking ethylene production unit of the refining enterprise, also known as ethylene cracking oil; the hydrocracking tail oil is a heavy fraction obtained by separating the fixed bed hydrocracking product; the slurry bed hydrogenation reactor is filled with a regenerated slurry bed hydrogenation catalyst; in the slurry bed hydrogenation reactor, the inferior heavy oil, sulfur powder and the regenerated slurry bed hydrogenation catalyst are mixed to form a slurry hydrogenation bed, and a hydrogenation reaction is carried out in an atmosphere containing hydrogen; the regenerated slurry bed hydrogenation catalyst accounts for 0.05%-0.1wt% of the inferior heavy oil and 80-100wt% of the sulfur powder; the reaction conditions of the slurry bed hydrogenation reactor are: reaction pressure 16-20MPa, reaction temperature 420-460℃, liquid hourly space velocity 1.0-3.0h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

[0035] B) Fraction B is cooled and separated to obtain crude naphthalene and a naphthalene fraction; the naphthalene fraction, fraction A, fraction C and hydrocracking tail oil are fed into a hydrotreating reactor for reaction.

[0036] Preferably, the hydrotreating reactor is filled with a hydroprotection catalyst and a hydrotreating catalyst in a volume ratio of 1:2-4 from top to bottom; the cooling separation conditions of fraction B are: pressure 0.08-0.12 MPa, cooling temperature 20-30°C; the reaction conditions of the hydrotreating reactor are: reaction pressure 11-15 MPa, reaction temperature 360-380°C, hourly space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:1; the mass ratio of ethylene tar to hydrocracking tail oil is (0.8-1.2):1.

[0037] C) Separating the obtained products to separate H2S and NH3, and the liquid phase products after separation enter the hydrocracking reactor for reaction, and the obtained products are separated to obtain C1-C4 fuel gas, BTX mixed triphenyls and fraction E with a boiling point greater than 165°C; fraction E is recycled to the hydrocracking reactor for further reaction.

[0038] Preferably, the hydrocracking reactor is filled with a hydrocracking catalyst and a naphthalene hydro-reforming catalyst in a ratio of 2-4:1 from top to bottom; the naphthalene hydro-reforming catalyst is the catalyst referred to in CN112275310B of Ningbo Zhongjin Petrochemical Co., Ltd.; the reaction conditions of the hydrocracking reactor are: reaction pressure 11-15 MPa, reaction temperature 370-390°C, liquid hourly space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

[0039] D) collecting the obtained C1-C4 fuel gas, crude naphthalene, BTX and mixed triphenyls.

[0040] The preparation method of the regenerated slurry bed hydrogenation catalyst comprises the following steps:

[0041] 1) Spent fixed-bed hydrogenation catalyst (the carrier is selected from alumina and silica-alumina, and the active component is selected from W, Mo and Ni) is calcined at 1300-1750° C. for 1-8 hours, pulverized, and sieved to obtain particles with a particle size of 50-90 μm.

[0042] 2) Iron powder with a particle size of 50-75 μm and a particle size dispersion of less than 10% is added to the particles in step 1) in a circular manner at a mass ratio of 1-4:100 at 20-35° C. and mixed evenly at an addition rate of 0.1-0.4 g / s.

[0043] 3) impregnating the product obtained in step 2) with 4-10 wt % of a mercaptan polyoxyethylene ether surfactant (preferably tert-hexyl mercaptan polyoxyethylene (11-12) ether and / or tert-nonyl mercaptan polyoxyethylene (17) ether) solution at a volume ratio of 1-3:1 at 20-35° C. for 1-10 h, drying at 100-130° C. for 1-10 h, and cooling to room temperature to obtain a regenerated slurry bed hydrogenation catalyst with a particle size of 60-100 μm.

[0044] The regenerated slurry bed hydrogenation catalyst of the present invention uses the waste fixed bed hydrogenation catalyst as the main component and iron powder as the auxiliary component. It can effectively utilize the hydrogenation activity of the original metal components of the waste fixed bed hydrogenation catalyst, and synergize with iron. It is applied to the slurry bed hydrogenation reaction system of the present invention. It is not only low-carbon and environmentally friendly, low-cost, but also has excellent hydrogenation activity. Among them: (a) In terms of particle size: the present invention removes impurities on the inner and outer surfaces of the waste fixed bed hydrogenation catalyst by high-temperature calcination, thereby obtaining microparticles with suitable particle size, which have more active sites than their original form. At the same time, the iron powder particle size is optimized, so that the obtained regenerated slurry bed hydrogenation catalyst has better activity and richer internal and external surface areas and pores. For the macromolecular asphalt and colloid in the inferior heavy oil that affects the operating life of the downstream hydrogenation reactor, whether based on the macromolecular deposition mechanism or the hydrogenation conversion mechanism, it can be removed by deposition and / or hydrogenation conversion method, thereby obtaining more high-value-added liquid products than conventional slurry bed catalysts. (b) Regarding the ratio of spent fixed-bed hydrogenation catalyst particles to iron powder: The present invention strictly controls the ratio of spent fixed-bed hydrogenation catalyst particles to iron powder to 1-4:100. (c) Regarding mercaptan polyoxyethylene ethers: As is common knowledge, smaller catalyst particle size results in higher surface energy, stronger inter-particle interactions, and agglomeration, which is detrimental to the hydrogenation reaction. To this end, the present invention impregnates the catalyst with mercaptan polyoxyethylene ethers to significantly reduce these interactions and enhance the binding between the catalyst and the oil-phase reaction feed. This allows macromolecular compounds in the feed to be better adsorbed onto active sites, thereby promoting the hydrogenation reaction and converting them into small molecules. Even if these cannot be hydrogenated, they are discharged from the reactor along with the catalyst and reaction products, reducing the coke yield. Furthermore, after the catalyst is surface-modified with a mercaptan polyoxyethylene ether surfactant, the mercaptan groups are converted to H2S through hydrogenation, increasing the H2S concentration in the reaction system, effectively ensuring the catalyst's activity and stability, and facilitating the hydrogenation reaction. Furthermore, in order to better exert the effect of thiol polyoxyethylene ether, it is necessary to optimize its solution concentration and the ratio with the catalyst during the impregnation process. Specific embodiments

[0046] Preparation Example of Regenerated Slurry Bed Hydrogenation Catalyst

[0047] The physicochemical properties of various types of spent fixed-bed hydrogenation catalysts, including hydrogenation protectants, hydrogenation finishing agents, and hydrocracking agents, used in the preparation of regenerated slurry-bed hydrogenation catalysts are listed in Table 1.

[0048] Table 1: Physicochemical properties of spent solid bed hydrogenation catalyst

[0049] serial number category shape Particle size, mm W, wt% Mo, wt% Ni, wt% A Hydrotreating catalysts Shamrock Strips 1.1-1.4 - 27.0 6.8 B Hydrogenation protection catalyst Four-leaf clover strips 2-4 - 2.4 1.6 C Hydrocracking catalyst cylindrical bars 1.2-1.5 19.8 - 5.4

[0050] It should be noted that the iron powder used in the following examples and comparative examples is Runze Gold Iron Powder produced by Shijiazhuang Runze Gold Mining Products Co., Ltd., with a particle size of 200 mesh (75 μm), 250 mesh (58 μm) and 300 mesh (50 μm), that is, the particle sizes are 75 μm, 58 μm, and 50 μm, respectively, and the iron content is more than 97%.

[0051] The spent catalyst is burned in a ZCGWL high-temperature box-type electric furnace produced by Shandong Zhongchen Electric Furnace Co., Ltd., whose heating elements are silicon-molybdenum rods.

[0052] In addition, unless otherwise specified, the raw materials, solvents and reagents used in the following examples of the present invention are all obtained through conventional commercial means.

[0053] Preparation Example 1 of Regenerated Slurry Bed Hydrogenation Catalyst

[0054] 100 g of spent solid bed hydrogenation catalyst A was calcined in a high-temperature box-type electric furnace at 1700° C. for 3 h to obtain a powdery substance, which was then sieved with a 300-mesh sieve to obtain particles of about 50 μm. At 20° C., 4 g of iron powder with a particle size of 200 mesh and a particle size dispersion of 7% was added to the above-mentioned particles at a rate of 0.1 g / s in a circular manner. The mixture was immersed in 200 ml of a 10 wt% tert-nonyl mercaptan polyoxyethylene (17) ether surfactant solution at 20° C. for 10 h to obtain a solid product. The product was dried at 100° C. for 10 h and naturally cooled to 20° C. to obtain a slurry bed hydrogenation catalyst C1 with a particle size of about 65 μm.

[0055] Preparation Example 2 of Regenerated Slurry Bed Hydrogenation Catalyst

[0056] 100 g of spent solid bed hydrogenation catalyst B was calcined in a high-temperature box-type electric furnace at 1500° C. for 8 h to obtain a powdered substance, which was then sieved with a 180-mesh sieve to obtain particles of approximately 88 μm. 3 g of iron powder with a particle size of 250 mesh and a particle size dispersion of 5% was added to the above-mentioned particles at a rate of 0.4 g / s at 30° C. in a circular manner. The mixture was impregnated with 100 ml of a 7 wt% tert-hexyl mercaptan polyoxyethylene (11-12) ether surfactant solution at 30° C. for 1 h to obtain a solid phase product. This product was dried at 130° C. for 1 h and naturally cooled to 30° C. to obtain a slurry bed hydrogenation catalyst C2 with a particle size of approximately 70 μm.

[0057] Preparation Example 3 of Regenerated Slurry Bed Hydrogenation Catalyst

[0058] 100 g of spent solid bed hydrogenation catalyst C was calcined in a high-temperature box-type electric furnace at 1450° C. for 1 h to obtain a powdery substance, which was then sieved with a 260-mesh sieve to obtain particles of about 57 μm. At 25° C., 2 g of iron powder with a particle size of 300 mesh and a particle size dispersion of 6% was added to the above-mentioned particles at a rate of 0.2 g / s in a circular manner. The mixture was immersed in 300 ml of a 4 wt% tert-nonyl mercaptan polyoxyethylene (17) ether surfactant solution at 25° C. for 6 h to obtain a solid phase product. The product was dried at 115° C. for 5 h and naturally cooled to 25° C. to obtain a slurry bed hydrogenation catalyst C3 with a particle size of about 55 μm.

[0059] Application Examples

[0060] In the following examples and comparative examples, the slurry bed hydrogenation reactions were performed using a fully mixed return slurry bed hydrogenation reactor. The process conditions are listed in Table 3. The catalysts used were C1, C2, and C3, respectively. The catalyst addition amounts relative to the feedstock and the sulfur addition amount are also listed in Table 3. The hydrogenation products were separated using a SH / T 0165 vacuum distillation apparatus manufactured by Xi'an Lianxing Experimental Instrument Co., Ltd.

[0061] The experimental evaluation indicators include reaction conversion rate, distillate oil yield, and coke yield:

[0062] Feed conversion rate = (1-unconverted oil / feed amount)*100%.

[0063] Distillate oil yield = distillate oil below 550°C / feed oil × 100%.

[0064] The coke yield is the data obtained by detecting the toluene insoluble matter in the liquid product.

[0065] In Examples 1-3, the slurry bed hydrogenation product is separated by distillation to obtain four fractions of <210°C, 210-220°C, 220-550°C, and >550°C. The latter is circulated back to the slurry bed reactor to continue reaction; the 210-220°C fraction is cooled and separated to obtain a crude naphthalene product and a naphthalene rear fraction; the naphthalene rear fraction, together with the <210°C, 220-550°C, and hydrocracking tail oil, enters a hydrotreating reactor for hydrotreating reaction, and the hydrotreating reaction zone is loaded from top to bottom with a commercialized hydrogenation protective agent FZC-103 and a hydrotreating catalyst FF-26 in the petrochemical industry. This hydrotreating liquid phase product then enters a hydrocracking reactor for hydrocracking reaction, and the hydrocracking reaction zone is loaded from top to bottom with a hydrocracking catalyst FC-26 and a naphthalene hydrogenation upgrading catalyst prepared in Example 1 of CN112275310B. The process conditions for the hydrotreating reaction and the hydrocracking reaction are listed in Table 4. The yields and properties of the final target products, C1-C4 fuel gas, BTX mixed triphenyls, and crude naphthalene, are listed in Table 5.

[0066] It should also be noted that the various reaction participants and process conditions used in the following examples and comparative examples are relatively typical examples. However, after a large number of experiments and verifications by the inventors of this case, other types of reaction participants and other process conditions listed above are also applicable and can also achieve the technical effects claimed in the present invention.

[0067] In the following examples, the inferior heavy oil used in Examples 1 and 3 is ethylene tar, and the inferior heavy oil used in Example 2 is catalytic slurry. The properties of the two are listed in Table 2.

[0068] Table 2: Properties of ethylene tar, catalytic slurry and hydrocracking tail oil

[0069]

[0070] Example 1

[0071] The catalyst used in the slurry bed hydrogenation reaction is C1 catalyst, with the catalyst dosage being 0.05wt% of ethylene tar and 90wt% of sulfur. The 210-220°C fraction is cooled and separated at 0.1MPa and 20°C. The resulting naphthalene fraction is mixed with the fractions below 210°C, 220-550°C, and hydrocracking tail oil, designated M1. The volume ratio of the hydroprotection catalyst to the hydrorefining catalyst in the hydrotreating reactor is 1:3; the volume ratio of the hydrocracking catalyst to the naphthalene hydro-upgrading catalyst in the hydrocracking reactor is 2:1.

[0072] Example 2

[0073] Compared with Example 1, the catalyst used in the slurry bed hydrogenation reaction is C2 catalyst, and the catalyst dosage is 0.1wt% of the catalyst slurry oil and 80wt% of the sulfur. The cooling separation conditions of the 210-220°C fraction are 0.1MPa and the cooling temperature is 25°C. The obtained naphthalene rear fraction and the mixture of <210°C, 220-550°C and hydrocracking tail oil are recorded as M2. The volume ratio of the hydrogenation protection catalyst to the hydrorefining catalyst in the hydrotreating reactor is 1:2; the volume ratio of the hydrocracking catalyst to the naphthalene hydro-upgrading catalyst in the hydrocracking reactor is 3:1.

[0074] Example 3

[0075] Compared with Example 1, the catalyst used in the slurry bed hydrogenation reaction is a C3 catalyst, and the catalyst dosage is 0.75wt% of ethylene tar and 100wt% of sulfur. The cooling separation conditions of the 210-220°C fraction are 0.1MPa and the cooling temperature is 30°C. The obtained naphthalene rear fraction and the mixture of <210°C, 220-550°C and hydrocracking tail oil are recorded as M3. The loading volume ratio of the hydrogenation protection catalyst and the hydrorefining catalyst in the hydrorefining reactor is 1:4; the loading volume ratio of the hydrocracking catalyst and the naphthalene hydrogenation upgrading catalyst in the hydrocracking reactor is 4:1.

[0076] Comparative Example 1

[0077] Compared to Example 1, the catalyst used in the slurry bed hydrogenation reaction was replaced with the prior art CN104907078B catalyst. The resulting mixture of the naphthalene fraction, the <210°C, 220-550°C, and the hydrocracking tail oil was designated M4. Other conditions were the same as in Example 1. The reaction results are shown in Table 3.

[0078] Table 3: Slurry bed hydrogenation process conditions, reaction results and cooling separation results of the 210-220℃ fraction

[0079]

[0080] Based on the above embodiments and comparative examples, it can be clearly seen that the regenerated slurry bed hydrogenation catalyst provided in the embodiments of the present invention has an excellent catalytic effect.

[0081] Table 4: Fixed bed hydrogenation unit process conditions

[0082]

[0083]

[0084] Table 5: Yield* and properties of target products

[0085] Case Example 1 Example 2 Example 3 Comparative Example 1 Crude naphthalene Yield, wt% 3.5 2.5 4.0 2.0 Melting point, °C 79 76 78 75 C1-C4 fuel gas Yield, wt% 7.5 8.9 7.6 15.2 BTX Yield, wt% 89.0 88.6 88.4 82.8 Benzene content, wt% 75.1 74.0 75.4 52.8

[0086] * For inferior heavy oil + hydrocracking tail oil

[0087] In the above examples, the yield of each component is calculated based on the sum of the inferior heavy oil and the hydrocracking tail oil.

[0088] It can be seen from the data in Tables 3-4 that the grading method of the regenerated slurry bed hydrogenation catalyst and the fixed bed hydrocracking unit catalyst of the present invention can efficiently convert inferior heavy oil and hydrocracking tail oil into high-value-added BTX triphenyl and crude naphthalene products, and the yield and properties of the obtained crude naphthalene product and BTX product are significantly better than those of the prior art.

[0089] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0090] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A mixed processing method of inferior heavy oil and hydrocracking tail oil, characterized in that include: A) Low-quality heavy oil is reacted in a slurry bed hydrogenation reactor containing a regenerated slurry bed hydrogenation catalyst. The hydrogenated product is distilled to obtain fraction A with a boiling point of less than 210°C, fraction B with a boiling point of 210-220°C, fraction C with a boiling point of 220-550°C, and fraction D with a boiling point of more than 550°C; Fraction D is recycled back to the slurry bed hydrogenation reactor to continue the reaction; The preparation of the regenerated slurry bed hydrogenation catalyst includes: 1) The spent fixed-bed hydrogenation catalyst is burned, pulverized, and sieved to obtain particles with a particle size of 50-90 μm; 2) Add iron powder with a particle size of 50-75 μm and a particle size dispersion of less than 10% to the granules at a mass ratio of 1-4:100 and mix thoroughly; 3) impregnating the product of step 2) with 4-10 wt% of a mercaptan polyoxyethylene ether surfactant solution at a volume ratio of 1-3:1, drying, and cooling to obtain a regenerated slurry bed hydrogenation catalyst having a particle size of 60-100 μm; B) Fraction B is cooled and separated to obtain crude naphthalene and a naphthalene fraction; the naphthalene fraction, fraction A, fraction C and hydrocracking tail oil are fed into a hydrotreating reactor for reaction; C) The resulting liquid product enters a hydrocracking reactor for reaction, and the resulting product is separated to obtain C1-C4 fuel gas, BTX mixed triphenyls, and fraction E with a boiling point greater than 165°C; fraction E is recycled back to the hydrocracking reactor for further reaction; D) Collect C1-C4 fuel gas, crude naphthalene, BTX and mixed triphenyl.

2. The method according to claim 1, wherein: The mass ratio of the inferior heavy oil to the hydrocracking tail oil is (0.8-1.2):

1.

3. The method according to claim 1, wherein: In step A), in a slurry bed hydrogenation reactor, low-quality heavy oil, sulfur powder and a regenerated slurry bed hydrogenation catalyst are mixed to form a slurry hydrogenation bed, and a hydrogenation reaction is carried out in an atmosphere containing hydrogen.

4. The method according to claim 3, wherein: In step A), The reaction conditions of the slurry bed hydrogenation reactor are: reaction pressure 16-20 MPa, reaction temperature 420-460°C, liquid hourly space velocity 1.0-3.0 h -1 , the volume ratio of hydrogen to oil is 1000-3000:

1.

5. The method according to claim 3, wherein: In step A), the regenerated slurry bed hydrogenation catalyst accounts for 0.05%-0.1wt% of the low-quality heavy oil and 80-100wt% of the sulfur powder.

6. The method according to claim 1, wherein: In step B), the hydrotreating reactor is sequentially filled with a hydroprotection catalyst and a hydrotreating catalyst in a volume ratio of 1:2-4 from top to bottom.

7. The method according to claim 1 or 6, wherein: In step B), the cooling and separation conditions of the fraction B are: pressure 0.08-0.12 MPa, cooling temperature 20-30°C.

8. The method according to claim 1 or 6, wherein: In step B), the reaction conditions of the hydrofining reactor are: reaction pressure 11-15 MPa, reaction temperature 360-380°C, space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:

1.

9. The method according to claim 1, wherein: In step C), the hydrocracking reactor is sequentially filled with a hydrocracking catalyst and a naphthalene hydro-reforming catalyst in a ratio of 2-4:1 from top to bottom.

10. The method according to claim 1 or 9, wherein: In step C), the reaction conditions of the hydrocracking reactor are: reaction pressure 11-15 MPa, reaction temperature 370-390°C, liquid hourly space velocity 0.2-0.6h -1 , the volume ratio of hydrogen to oil is 1000-3000:1.

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