Method for producing low-sulfur petroleum coke and apparatus therefor

Abstract

The present application relates to the technical field of petroleum chemical industry, in particular to a method for producing low-sulfur petroleum coke and a device thereof, and a negative electrode material. The method comprises: (1) carrying out hydrodesulfurization treatment on raw oil and a catalyst in the presence of hydrogen to obtain a gas component and a liquid-solid component; the catalyst is selected from at least one complex formed by bonding an active metal and an organic ligand through a coordination bond; (2) separating the liquid-solid component to obtain desolid oil and a solid-containing tail oil component; distilling and cutting the desolid oil to obtain a light component and a heavy component; (3) carrying out coking treatment on the heavy component to obtain low-sulfur petroleum coke. The method not only effectively improves the conversion rate of the raw oil, but also obtains high-quality low-sulfur petroleum coke; meanwhile, the metal in the raw oil and the catalyst is also recycled.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, and in particular to a method for producing low-sulfur petroleum coke, a device for producing low-sulfur petroleum coke, and a negative electrode material. Background Art

[0002] Petroleum coke, a solid product obtained from delayed coking units in oil refineries, is an irreplaceable raw material for a variety of industries, including glass, steel, and electrolytic aluminum. The quality of petroleum coke is significantly influenced by the type of crude oil processed by the refinery, as most of the sulfur and impurities in the crude oil are concentrated in the petroleum coke. Petroleum coke is categorized by sulfur content. Low-sulfur petroleum coke with a sulfur content of 3% or less is primarily used in the steel and aluminum industries for electrode production. High-sulfur coke with a sulfur content exceeding 3% is considered an economical alternative to thermal coal, primarily used in the cement, power, and steel industries. In most countries around the world, high-sulfur petroleum coke is still primarily used as a fuel for power plants. High-quality, low-sulfur petroleum coke is widely used in the steel, aluminum, and carbon industries, significantly increasing its value.

[0003] As the trend toward heavier oil resources continues to intensify, my country's crude oil imports, particularly high-sulfur crude oil, are gradually increasing, and the production of high-sulfur petroleum coke is also increasing. Reducing the sulfur content of coking feedstock is the key to reducing high-sulfur coke production and producing low-sulfur coke.

[0004] CN103102986A discloses a combined process for residue hydrotreating and delayed coking. Residue oil, coker gas oil, and hydrogen are mixed and reacted in a hydrotreating unit. The resulting hydrotreated residue oil and vacuum gas oil are then separated and mixed or mixed with other conventional feedstocks and fed into a delayed coking unit. The coking products are then separated, with the coker gas oil being recycled to the residue hydrotreating unit. While this method can produce low-sulfur petroleum coke, it imposes strict restrictions on the asphaltene and metal content of the feed.

[0005] CN103059997A discloses a combined process of residue hydrotreating and delayed coking. The residue hydrotreating utilizes an ebullated-bed hydrotreating process, including: The liquid phase product of the residue feedstock after ebullated-bed hydrotreating is directly fed into a coking fractionation tower without fractionation, where it is countercurrently contacted with the oil and gas generated by the coking process, eluting coke powder carried by the high-temperature oil and gas. The light fractions generated by the hydrogenation are then discharged from the unit together with the light fractions generated by the coking process, and the fractions above the wax oil are recycled back to the delayed coking unit. This method combines ebullated-bed residue hydrotreating with delayed coking, but the limited domestic industrial application of ebullated-bed residue hydrotreating units limits the widespread application of this process. Summary of the Invention

[0006] The present application aims to overcome the problems of low conversion rate of raw materials, high sulfur content in the obtained petroleum coke, and complex process flow in the prior art for producing low-sulfur petroleum coke, and provides a method for producing low-sulfur petroleum coke, a device for producing low-sulfur petroleum coke, and a negative electrode material, which effectively improves the conversion rate of raw oil and obtains high-quality low-sulfur petroleum coke, and also realizes the recovery of metals in the raw oil and catalyst.

[0007] To achieve the above-mentioned purpose, the present application provides a method for producing low-sulfur petroleum coke, which comprises the following steps:

[0008] (1) subjecting raw oil and a catalyst to hydrodesulfurization treatment in the presence of hydrogen to obtain a gas component and a liquid-solid component; the catalyst is selected from at least one complex formed by bonding an active metal and an organic ligand through a coordination bond;

[0009] (2) separating the liquid-solid component to obtain desolid oil and solid-containing tail oil component; subjecting the desolid oil to distillation cutting to obtain light component and heavy component;

[0010] (3) subjecting the heavy component to coking treatment to obtain low-sulfur petroleum coke.

[0011] Preferably, the catalyst has a composition shown in formula (I): MO a [R(COO) x ] b (I),

[0012] In formula I, M is selected from at least one metal element in group VB, group VIB, group VIII and group IB, R is selected from C3-C 20 hydrocarbon group, x is selected from 1, 2 and 3, a is selected from a positive number from 0 to 5, and b is selected from a positive number from 1 to 6.

[0013] Preferably, the sulfur content in the raw oil is ≥3wt%, the asphaltene content is ≥11wt%, and the heavy metal content in terms of Ni and / or V is ≥150ppm.

[0014] Preferably, the separation is selected from solvent extraction separation, and the process of the solvent extraction separation comprises: contacting the liquid-solid component with a solvent and performing the solvent extraction separation.

[0015] Preferably, the method further comprises: dividing the solid-containing tail oil component into two streams, subjecting the first stream of solid-containing tail oil component to calcination to obtain metal residue; and returning the second stream of solid-containing tail oil component and subjecting it to the hydrodesulfurization treatment.

[0016] The present application provides a device for producing low-sulfur petroleum coke, which comprises: reaction unit, separation unit, distillation unit and coking unit connected in sequence;

[0017] The reaction unit is used to carry out hydrodesulfurization treatment on the raw oil and the catalyst in the presence of hydrogen to obtain a gas component and a liquid-solid component; the separation unit is used to separate the liquid-solid component to obtain a desolidified oil and a solid-containing tail oil component; the distillation unit is used to distill and cut the desolidified oil to obtain a light component and a heavy component; the coking unit is used to coke the heavy component to obtain low-sulfur petroleum coke.

[0018] Preferably, the reaction unit is selected from a slurry bed reactor.

[0019] A third aspect of the present invention provides a negative electrode material, which is obtained by sequentially crushing and graphitizing the low-sulfur petroleum coke prepared by the method provided by the first aspect.

[0020] Through the above technical solution, the method provided by the present invention adopts a combined process of hydrodesulfurization (especially slurry bed hydrodesulfurization pretreatment) and delayed coking, and combines it with a specific catalyst to effectively remove the sulfur content in the raw oil. This not only achieves efficient conversion of such inferior raw materials, but also can obtain high-quality low-sulfur petroleum coke with high economic added value. In addition, the method also solves the problem of metal recovery in the catalyst and raw oil.

[0021] At the same time, the low-sulfur petroleum coke prepared by the method provided by the present invention is used as a negative electrode material, which opens up the source of negative electrode plate raw materials while ensuring high electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a device for producing low-sulfur petroleum coke provided by the present invention;

[0023] Figure 2 is the infrared spectrum of the catalyst used in Example 1-2.

[0024] Description of Reference Numerals

[0025] I, reaction unit; II, separation unit; III, distillation unit; IV, coking unit; V, roasting unit; VI, fractionation unit;

[0026] 1. Crude oil; 2. Hydrogen; 3. Catalyst; 4. Gas components; 5. Liquid-solid components; 6. Desolidified oil; 7. Solid-containing tail oil component; 7-i. First solid-containing tail oil component; 7-ii. Second solid-containing tail oil component; 8. Light components; 9. Heavy components; 10. Low-sulfur petroleum coke; 11. Gas-liquid mixture; 12. Coking gas; 13. Coking naphtha; 14. Coking diesel; 15. Coking wax oil. DETAILED DESCRIPTION

[0027] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0028] In the present invention, unless otherwise specified, the "top" of a container refers to the position of 0-10% from the top to the bottom of the container; the "upper part" of a container refers to the position of 10-40% from the top to the bottom of the container; the "middle" of a container refers to the position of 40-60% from the top to the bottom of the container; the "lower part" of a container refers to the position of 60-90% from the top to the bottom of the container; and the "bottom" of a container refers to the position of 90-100% from the top to the bottom of the container.

[0029] A first aspect of the present invention provides a method for producing low-sulfur petroleum coke, the method comprising the following steps:

[0030] (1) subjecting the feedstock oil and the catalyst to a hydrodesulfurization treatment in the presence of hydrogen to obtain a gas component and a liquid-solid component; the catalyst is selected from at least one complex formed by a coordination bond between an active metal and an organic ligand;

[0031] (2) separating the liquid and solid components to obtain a desolidified oil and a solid-containing tail oil component; and distilling and cutting the desolidified oil to obtain a light component and a heavy component;

[0032] (3) coking the heavy component to obtain low-sulfur petroleum coke.

[0033] The inventors of the present invention have discovered through research that the problem of high sulfur content in petroleum coke faced by the delayed coking process can be solved by adopting a combined process of hydrodesulfurization and delayed coking. Therefore, a combined process of hydrodesulfurization and delayed coking suitable for producing low-sulfur petroleum coke is provided, which not only solves the outlet of high-sulfur feedstock oil, improves resource utilization, and reduces environmental pollution; at the same time, a specific catalyst is used, which has high oil phase dispersibility and hydrodesulfurization selectivity, and directionally adsorbs and desulfurizes sulfur-containing compounds in the feedstock oil, ensuring a high desulfurization effect while maintaining a certain residual carbon content, avoiding over-saturation of heavy aromatic components due to desulfurization, thereby improving the yield of low-sulfur petroleum coke.

[0034] At the same time, the solid-containing tail oil fraction is split into two streams. The first stream is calcined to produce a metal residue that effectively recovers the catalyst and metals from the feed oil. The second stream is returned for hydrodesulfurization (i.e., the unconverted oil is recycled), further improving the feed oil conversion rate and reducing costs. This setup effectively solves the problem of discarded solids disposal.

[0035] In the present invention, unless otherwise specified, the catalyst consists solely of the complex and does not contain any solid support component. However, as needed, the catalyst of the present invention may also be present and used in the form of a composition with a liquid component capable of dispersing the catalyst, such as an organic solvent and an organic ligand compound.

[0036] In some embodiments of the present invention, preferably, the catalyst has a composition shown in formula (I): MO a [R(COO) x ] b (I), wherein M is selected from at least one metal element of Group VB, Group VIB, Group VIII and Group IB, and R is selected from C3-C 20 Hydrocarbyl, x is selected from 1, 2, 3, a is selected from a positive number of 0-5, and b is selected from a positive number of 1-6.

[0037] In the present invention, as shown in Formula I, M represents an active metal, R(COO) x represents an organic ligand, R represents a hydrocarbon group in the organic ligand, COO represents a coordinating group in the organic ligand, x represents the number of coordinating groups in the organic ligand, a represents the molar ratio of non-coordinating oxygen atoms connected to the active metal M to the total amount of metal, and b represents the molar ratio of the organic ligand to the total amount of metal. That is, the catalyst provided by the present invention is selected from at least one complex formed by a coordinate bond between an active metal and an organic ligand, wherein the organic ligand comprises a hydrocarbon group and a coordinating group, wherein the coordinating group is a -C(=O)-O group, and forms a coordination bond with the active metal central atom or central ion via an oxygen atom.

[0038] According to the present invention, the catalyst can be a mixture of multiple different complexes, and the molar ratios a and b of oxygen atoms and organic ligands to the total amount of metal in the catalyst composition are calculated values ​​based on metal content and elemental composition analysis, and can therefore be non-integer.

[0039] In some embodiments of the present invention, further preferably, in Formula I, M is selected from at least one metal element selected from V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Pd, and R is selected from C4-C 20 Normal alkyl, C4-C 20 Isomeric alkyl, C5-C 20 Containing cycloalkyl and C6-C 20 Aryl, x is selected from 1 and 2, a is selected from a positive number of 1-3, and b is selected from a positive number of 2-5.

[0040] In some embodiments of the present invention, more preferably, in Formula I, M is selected from at least one metal element of Mo, W, Ni, V, Co and Fe, and R is selected from C5-C 11Normal alkyl, C5-C 11 Isomeric alkyl, C5-C 12 Containing cycloalkyl and C6-C 12 Aryl.

[0041] In some embodiments of the present invention, preferably, in the catalyst, the organic ligand is selected from at least one of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum acid, salicylic acid, benzoic acid and phenylacetic acid.

[0042] In some embodiments of the present invention, the catalyst includes but is not limited to (MoCo)O 1.27 [(C7H 16 )(COO)] 2.45 、(Mo 0.7 Ni 0.3 )O 1.4 [(C7H 16 )(COO)] 3.27 、MoO[(i-C7H 16 )(COO)] 2.88 wait.

[0043] In some embodiments of the present invention, preferably, the infrared spectrum of the catalyst is between 700-1000 cm -1 There are MO and M=O vibration characteristic peaks at 1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at the position of -C(=O)-O group coordinated with metal M.

[0044] In some embodiments of the present invention, preferably, the active metal content in the catalyst, calculated as M, is 5-35 wt%, for example, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 25 wt%, 35 wt%, and any value in a range consisting of any two of these values, preferably 8-25 wt%, more preferably 10-25 wt%, and even more preferably 10-20 wt%. The above-mentioned content range can reduce production costs while ensuring the catalytic performance of the catalyst.

[0045] In some embodiments of the present invention, preferably, in step (1), the sulfur content in the feed oil is ≥3wt%, the asphaltene content is ≥11wt%, and the heavy metal content calculated as Ni and / or V is ≥150ppm; further preferably, the sulfur content in the feed oil is 3-10wt%, the asphaltene content is 11-25wt%, and the heavy metal content calculated as Ni and / or V is 150-700ppm.

[0046] In the present invention, the source of the feedstock oil has a wide range of options, as long as the feedstock oil meets the above-mentioned limitations. Preferably, the feedstock oil is selected from high-sulfur low-quality oil, preferably at least one selected from high-sulfur crude oil, high-sulfur deoiled asphalt, and high-sulfur vacuum residue.

[0047] In some embodiments of the present invention, preferably, in step (1), the hydrodesulfurization treatment is carried out in a slurry bed reactor. A slurry bed reactor has a uniform distribution of gas, liquid, and solid phases, and a highly dispersed catalyst suspended in a liquid medium, enabling effective contact with hydrogen and oil phases. Heat transfer is uniform, the reaction temperature is uniform, and there are no hot spots in the reactor. No online loading or unloading of agents is required, and the catalyst and the feedstock oil enter the reactor together for reaction.

[0048] In the present invention, in step (1), the hydrodesulfurization treatment is intended to remove sulfur from the feedstock oil, thereby reducing the sulfur content of the feedstock entering the coking unit to produce low-sulfur petroleum coke.

[0049] In some embodiments of the present invention, preferably, the hydrodesulfurization treatment conditions include: temperature of 380-440°C, preferably 400-430°C; hydrogen partial pressure of 8-20 MPa, preferably 10-18 MPa; volume space velocity of 0.05-0.6 h -1 , preferably 0.1-0.5h -1 The catalyst concentration, calculated as the metal element, is 200-20,000 μg / g, preferably 500-10,000 μg / g. Meeting this range is more conducive to removing sulfur from the feedstock, thereby improving the quality of low-sulfur petroleum coke. In the present invention, all pressure parameters refer to gauge pressure.

[0050] In the present invention, in step (2), the separation is intended to remove the catalyst from the liquid-solid components and the heavy metals from the feed oil to obtain a desolidified oil and a solid-containing tail oil component. Preferably, the separation method is selected from filtration separation, centrifugal separation, and solvent extraction separation. Compared with solvent extraction separation, filtration separation and centrifugal separation are limited by the inability of industrial equipment to achieve high-temperature filtration or high-temperature centrifugation, and the low processing capacity of the equipment, making it difficult to achieve industrial processing.

[0051] In some embodiments of the present invention, preferably, in step (2), the solvent extraction separation process includes: contacting the liquid and solid components with a solvent and performing the solvent extraction separation.

[0052] In some embodiments of the present invention, preferably, the conditions for the solvent extraction separation include: a temperature of 40-300° C., preferably 80-240° C.; and a pressure of 0.1-6 MPa, preferably 0.1-3 MPa.

[0053] In some embodiments of the present invention, preferably, the amount of the solvent is 1-10 parts by weight, preferably 1-5 parts by weight, relative to 1 part by weight of the desolidified oil.

[0054] In the present invention, a wide range of solvents can be selected, as long as the solvent can remove the solid content (catalyst, heavy metals) in the liquid-solid composition. Preferably, the solvent is selected from at least one of C3-C8 alkanes, C3-C8 olefins, toluene, and light naphtha, and is preferably selected from C4-C5 alkanes and / or toluene. In the present invention, C4-C5 alkanes include, but are not limited to, n-butane, isobutane, n-pentane, and the like.

[0055] In some embodiments of the present invention, preferably, the yield of the desolidified oil is 40-95% based on the total weight of the raw oil.

[0056] In some embodiments of the present invention, preferably, the distillation cutting temperature is 330-370°C, for example, 330°C, 340°C, 350°C, 360°C, 370°C, and any value in the range consisting of any two values.

[0057] In the present invention, the light component is selected from liquid components with a distillation range of ≤330°C; the heavy component contains the main coke-prone components in the hydrodesulfurization product. Preferably, the heavy component satisfies the following requirements: the heavy metal content calculated as Ni and / or V is ≤50ppm.

[0058] In some embodiments of the present invention, preferably, in step (3), the low-sulfur petroleum coke satisfies: a sulfur content of ≤3 wt%, a volatile matter content of ≤12 wt%, and an ash content of ≤0.5 wt%.

[0059] In some embodiments of the present invention, the coking process preferably comprises: a discharge temperature of 490-515°C, a pressure of 0.12-0.8 MPa, and a coking feedstock recycle ratio of 0-1. In the present invention, the discharge temperature refers to the outlet temperature of the coking furnace; the pressure refers to the pressure at the top of the coke tower; and the recycle ratio refers to the ratio of the recycle oil volume to the fresh feedstock volume. Conventional recycle oil is the heaviest portion of the coking distillate oil and is recycled.

[0060] In some embodiments of the present invention, the gas-liquid mixture obtained from the coking process is preferably fractionated to obtain coking gas and coking distillate oil, wherein the coking distillate oil includes coking naphtha, coking diesel, and coking gas oil. In the present invention, the fractionation is conventional fractionation, which is not limited thereto.

[0061] In some embodiments of the present invention, preferably, the method further comprises: dividing the solid-containing tail oil component into two streams, roasting the first solid-containing tail oil component to obtain metal residue; and returning the second solid-containing tail oil component to undergo the hydrodesulfurization treatment.

[0062] In some embodiments of the present invention, it is further preferred that the weight ratio of the first solid tail oil component to the second solid tail oil component is 0-100:100-0, preferably 5-100:95-0, and more preferably 90-100:10-0. In the present invention, the above weight ratio is selected and adjusted based on specific working conditions.

[0063] In the present invention, when the weight ratio of the first solid-containing tail oil component and the second solid-containing tail oil component is 0:100, it means that all the solid-containing tail oil components are returned and subjected to the hydrodesulfurization treatment (i.e., recycled) to obtain low-sulfur petroleum coke; when the weight ratio of the first solid-containing tail oil component and the second solid-containing tail oil component is 100:0, it means that all the solid-containing tail oil components are roasted to recover the catalyst and metals in the raw oil; when the weight ratio of the first solid-containing tail oil component and the second solid-containing tail oil component is selected from ≠0:100 and ≠100:0, it means that the solid-containing tail oil component is divided into two strands, which are roasted and recycled respectively.

[0064] In some embodiments of the present invention, preferably, the calcination conditions include: a temperature of 400-600° C., preferably 450-550° C.; and a calcination time of 10-240 min, preferably 30-180 min.

[0065] In some embodiments of the present invention, preferably, the calcination is carried out in an oxygen-containing gas, and the oxygen-containing gas is selected from air and / or oxygen, preferably oxygen.

[0066] In some embodiments of the present invention, preferably, the feed ratio of the oxygen-containing gas to the solid-containing tail oil component, measured in oxygen, is 20-150 mL / g. The feed ratio refers to the amount of oxygen-containing gas used, measured in oxygen, per 1 g of the solid-containing tail oil component. Using the above process conditions, the tail oil can be completely roasted, more than 90% of the carbon is removed, and the metals in the tail oil can be effectively enriched.

[0067] The second aspect of the present invention provides a schematic diagram of the structure of a device for producing low-sulfur petroleum coke. Figure 1 As shown by Figure 1 It can be seen that the device comprises: a reaction unit I, a separation unit II, a distillation unit III and a coking unit IV connected in sequence;

[0068] The reaction unit I is used for carrying out hydrodesulfurization treatment on the raw oil 1 and the catalyst 3 in the presence of hydrogen 2 to obtain a gas component 4 and a liquid-solid component 5; the separation unit II is used for separating the liquid-solid component 5 to obtain a solid-removed oil 6 and a solid-containing tail oil component 7; the distillation unit III is used for carrying out distillation cutting on the solid-removed oil 6 to obtain a light component 8 and a heavy component 9; and the coking unit IV is used for carrying out coking treatment on the heavy component 9 to obtain a low-sulfur petroleum coke 10.

[0069] According to the present application, preferably, as shown in Figure 1 The device further comprises a calcination unit V connected to the separation unit II, which is used for carrying out calcination on a first solid-containing tail oil component 7-i to obtain a metal residue.

[0070] According to the present application, preferably, as shown in Figure 1 The solid-containing tail oil component outlet of the separation unit II is connected to the reaction unit I, which is used for returning and carrying out the hydrodesulfurization treatment on a second solid-containing tail oil component 7-ii.

[0071] In one specific embodiment of the present application, as shown in Figure 1 The separation unit II is respectively connected to the calcination unit V and the reaction unit I, which are respectively used for carrying out the calcination on the first solid-containing tail oil component 7-i and carrying out the hydrodesulfurization treatment on the second solid-containing tail oil component 7-ii.

[0072] According to the present application, preferably, as shown in Figure 1 The device further comprises a fractionation unit VI connected to the coking unit IV, which is used for carrying out fractionation on a gas-liquid mixture 11 obtained by the coking treatment to obtain a coking gas 12, a coking naphtha 13, a coking diesel 14 and a coking wax oil 15.

[0073] In the present application, preferably, as shown in Figure 1 The reaction unit I is selected from a slurry bed reactor, the top of which obtains the gas component 4 and the bottom of which obtains the liquid-solid component 5; the separation unit II is selected from a solid-liquid separation device, preferably a solvent extraction column, the top of which obtains the solid-removed oil 6 and the bottom of which obtains the solid-containing tail oil component 7; the distillation unit III is selected from a distillation column, the top of which obtains the light component 8 and the bottom of which obtains the heavy component 9; the coking unit IV is selected from a delayed coking device, the top of which obtains the gas-liquid mixture 11 and the bottom of which obtains the low-sulfur petroleum coke 10; the fractionation unit VI is selected from a fractionation column, the top of which obtains the coking gas 12, the side of which introduces the coking naphtha 13 and the coking diesel 14, and the bottom of which obtains the coking wax oil 15; and the calcination unit V is selected from a calcination device, which obtains the metal residue.

[0074] According to a particularly preferred embodiment of the present invention, a method for producing low-sulfur petroleum coke comprises the following steps:

[0075] (1) subjecting a feedstock oil and a catalyst to a hydrodesulfurization treatment in the presence of hydrogen to obtain a gas component and a liquid-solid component; the catalyst is selected from at least one complex formed by a coordination bond between an active metal and an organic ligand; the hydrodesulfurization treatment is carried out in a slurry bed reactor;

[0076] (2) contacting the liquid and solid components with a solvent and performing solvent extraction separation to obtain a desolidified oil and a solid-containing tail oil component; and distilling and cutting the desolidified oil to obtain a light component and a heavy component;

[0077] (3) coking the heavy component to obtain low-sulfur petroleum coke;

[0078] (4) dividing the solid tail oil component into two streams, wherein the first stream of the solid tail oil component is roasted to obtain a metal residue; and the second stream of the solid tail oil component is returned and subjected to the hydrodesulfurization treatment;

[0079] Wherein, the catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I),

[0080] In Formula I, M is selected from at least one metal element of Group VB, Group VIB, Group VIII and Group IB, and R is selected from C3-C 20 A hydrocarbon group, x is selected from 1, 2, and 3, a is selected from a positive number of 0 to 5, and b is selected from a positive number of 1 to 6;

[0081] Wherein, the weight ratio of the first solid tail oil component to the second solid tail oil component is 90-100:10-0.

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

[0083] The density and kinematic viscosity parameters of high-sulfur low-quality oil are measured using GB / T 13377; the carbon residue rate parameter is measured using GB / T 17144; the sulfur content parameter is measured using GB / T 17040; the nitrogen content parameter is measured using H / T0657; and the asphaltene content parameter is measured using RIPP10-90.

[0084] The metal content of the obtained product was determined using a SPECTRO ARCOS SOP plasma optical emission spectrometer using inductively coupled plasma optical emission spectrometry (ICP-OES). The measurement conditions were a closed optical chamber filled with argon, vertical observation, and a wavelength range of 130-770 nm.

[0085] The elemental composition of the obtained product was determined as follows: the C and H contents were determined using the SH0656 method using an Italian Cara Erba EA1110 elemental analyzer; the S content was determined using the energy dispersive X-ray fluorescence spectrometry method GB17040 using an Oxford Lab-X3500 desktop XRF analyzer; and the O content was determined using the O-content method.

[0086] The infrared spectrum of the obtained product was measured using a NICOLET IS50 spectrometer from Thermo Fisher Scientific. The measurement conditions were scanning wavelength from 400 to 4000 cm-1 and scanning times 16 times. ZnSe crystal and HgCdTe infrared detector were used together to measure the attenuated total reflectance (ATR) of the sample with a resolution of 4 cm -1 .

[0087] In the following examples, the high-sulfur low-quality oil was selected from feedstock oil A, and its specific properties are shown in Table 1.

[0088]

[0089]

[0090] Example 1

[0091] (1) The above-mentioned raw oil A and catalyst C1 ((Mo 0.7 Ni 0.3 )O 1.4 [(C7H 16 )COO)] 3.27 , active metal content of 12.76 wt%) was subjected to hydrodesulfurization treatment in a slurry bed reactor in the presence of hydrogen to obtain gas components and liquid-solid components. The operating conditions of the hydrodesulfurization treatment and the properties of the products are shown in Table 2;

[0092] (2) contacting the liquid and solid components with a solvent and subjecting them to solvent extraction separation to obtain a desolidified oil and a solid-containing tail oil component. The operating conditions and product properties of the solvent extraction separation are shown in Table 3; the desolidified oil is distilled and cut at 350° C. to obtain a light component and a heavy component;

[0093] (3) The above-mentioned heavy components are coked to obtain coking gas, coking naphtha, coking diesel, coking gas oil and petroleum coke. The distribution of the combined process products and the properties of the petroleum coke are shown in Table 4;

[0094] (4) All the above-mentioned solid tail oil-containing components were roasted to obtain metal residues. The roasting operating conditions and product properties are shown in Table 5.

[0095] The infrared spectrum of the catalyst C1 is as follows: Figure 2 As shown byFigure 2 It can be seen that catalyst C1 has a -1 、1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at 700-1000cm -1 There are MO and M=O vibration characteristic peaks at 1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak of -C(=O)-O group coordinated with metal at the position, and 1350-1450cm -1 A characteristic peak at 1500-1610 cm -1 The distance between the peaks of a characteristic peak at the position is greater than 145 cm -1 , indicating that at least part of the complex in catalyst C1 has a bimetallic monodentate coordination structure.

[0096] Example 2

[0097] (1) The above-mentioned raw oil A and catalyst C2 ((MoCo)O 1.27 [(C7H 16 )(COO)] 2.45 , active metal content of 11.75wt%) was subjected to hydrodesulfurization treatment in a slurry bed reactor in the presence of hydrogen to obtain gas components and liquid-solid components. The operating conditions of the hydrodesulfurization treatment and the properties of the products are shown in Table 2;

[0098] (2) The liquid and solid components and the solvent were mixed and centrifuged to obtain desolidified oil and solid-containing tail oil components. The operating conditions of the centrifugal separation and the properties of the products are shown in Table 3;

[0099] The desolidified oil is distilled and cut at 350°C to obtain light components and heavy components;

[0100] The solid tail oil component is divided into a first solid tail oil component and a second solid tail oil component in a weight ratio of 10:90, and the second solid tail oil component is returned and subjected to the above-mentioned hydrodesulfurization treatment;

[0101] (3) The above-mentioned heavy components are coked to obtain coking gas, coking naphtha, coking diesel, coking gas oil and petroleum coke. The distribution of the combined process products and the properties of the petroleum coke are shown in Table 4;

[0102] (4) The first solid tail oil component was roasted to obtain metal residue. The roasting operating conditions and product properties are shown in Table 5.

[0103] Among them, the infrared spectrum of the above catalyst C2 is as follows Figure 2 As shown by Figure 2It can be seen that the catalyst C2 has a -1 、1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak at 700-1000cm -1 There are MO and M=O vibration characteristic peaks at 1350-1450cm -1 and 1500-1610cm -1 There is a characteristic peak of -C(=O)-O group coordinated with metal at the position, and 1350-1450cm -1 A characteristic peak at 1500-1610 cm -1 The distance between the peaks of a characteristic peak at the position is greater than 145 cm -1 , indicating that at least part of the complex in catalyst C2 has a bimetallic monodentate coordination structure.

[0104] Example 3

[0105] The method of Example 1 is as follows, except that

[0106] In step (2), the type of solvent was changed to toluene to obtain desolidified oil and solid-containing tail oil components. The operating conditions and product properties of the solvent extraction separation are shown in Table 3;

[0107] In step (3), coking gas, coking naphtha, coking diesel, coking gas oil and petroleum coke are obtained. The distribution of the combined process products and the properties of the petroleum coke are shown in Table 4;

[0108] In step (4), a metal residue is obtained. The calcination operating conditions and product properties are shown in Table 5.

[0109] Comparative Example 1

[0110] The method of Example 1 is followed, except that steps (1)-(2) and (4) are omitted, i.e.,

[0111] The above-mentioned raw oil A is directly subjected to the coking treatment to obtain coking gas, coking naphtha, coking diesel, coking wax oil and petroleum coke. The distribution of coking process products and the properties of petroleum coke are shown in Table 4.

[0112] Table 2

[0113]

[0114] Table 3

[0115]

[0116]

[0117] Note: * - weight ratio of solvent to de-oiled oil.

[0118] Table 4

[0119]

[0120] Note: ** - total product distribution based on weight of feed oil.

[0121] Table 5

[0122]

[0123] Note: # - ratio of oxygen-containing gas to feed containing solid tail oil components on an oxygen basis.

[0124] From the results of Tables 2-5, it can be seen that Examples 1-3 used the method provided by the present application, with high-sulfur inferior oil as the raw material, combined with a specific oil-soluble hydrogenation catalyst and process conditions, to obtain low-sulfur petroleum coke with low sulfur content and low yield, which can meet the requirements of long-period operation of the device.

[0125] Compared with Comparative Example 1 which directly used coking treatment, the combined method provided by the present application for processing high-sulfur inferior raw oil A obtained higher yield of coking naphtha and coking diesel, and lower yield of coking gas oil; compared with Comparative Example 1 which directly used coking treatment, 27.5% of high-sulfur coke was produced, and using the combined processing method provided by the present application, not only no high-sulfur coke was produced, but also high-quality low-sulfur coke with sulfur content of only 2.2wt% and metal Ni+V of 35μg / g was obtained, which can be used for negative electrode materials, has higher value, and meets environmental protection requirements.

[0126] For the rejected de-oiled pitch, the method of roasting can achieve 75% recovery of the catalyst and the metal in the raw oil, and the recovered metal has high content and can be used as rich ore material.

[0127] 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 all fall within the protection scope of the present application.

Claims

1. A method for producing low-sulfur petroleum coke, characterized in that: The method comprises the following steps: (1) subjecting the feedstock oil and the catalyst to a hydrodesulfurization treatment in the presence of hydrogen to obtain a gas component and a liquid-solid component; the catalyst is selected from at least one complex formed by a coordination bond between an active metal and an organic ligand; (2) separating the liquid and solid components to obtain a desolidified oil and a solid-containing tail oil component; and distilling and cutting the desolidified oil to obtain a light component and a heavy component; (3) coking the heavy component to obtain low-sulfur petroleum coke; Wherein, the catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I), wherein M is selected from at least one metal element of Group VB, Group VIB, Group VIII and Group IB, and R is selected from C3-C 20 A hydrocarbon group, x is selected from 1, 2, and 3, a is selected from a positive number of 0 to 5, and b is selected from a positive number of 1 to 6; the catalyst has an active metal content calculated as M of 5 to 35 wt%; The hydrodesulfurization treatment conditions include: temperature of 380-440°C; hydrogen partial pressure of 8-20 MPa; volume space velocity of 0.05-0.6 h -1 The concentration of the catalyst in terms of metal elements is 200-20000 μg / g; the coking treatment conditions include: a discharge temperature of 490-515°C, a pressure of 0.12-0.8 MPa, and a circulation ratio of coking raw materials of 0-1.

2. The method according to claim 1, wherein In step (1), In Formula I, M is selected from at least one metal element selected from V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Pd, and R is selected from C4-C 20 Normal alkyl, C4-C 20 Isomeric alkyl, C5-C 20 Containing cycloalkyl and C6-C 20 Aryl, x is selected from 1 and 2, a is selected from a positive number of 1-3, and b is selected from a positive number of 2-5.

3. The method according to claim 2, wherein: In Formula I, M is selected from at least one metal element of Mo, W, Ni, V, Co and Fe, and R is selected from C5-C 11 Normal alkyl, C5-C 11 Isomeric alkyl, C5-C 12 Containing cycloalkyl and C6-C 12 Aryl.

4. The method according to claim 1, wherein In the catalyst, the organic ligand is selected from at least one of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum acid, salicylic acid, benzoic acid and phenylacetic acid; And / or, the infrared spectrum of the catalyst is in the range of 700-1000 cm -1 There are MO and M=O vibration characteristic peaks at 1350-1450cm -1 and 1500-1610cm -1 The position has a characteristic peak of -C(=O)-O group coordinated with metal M; And / or, in the catalyst, the active metal content calculated as M is 8-25 wt%.

5. The method according to claim 4, wherein In the catalyst, the active metal content calculated as M is 10-25 wt%.

6. The method according to claim 4, wherein: In the catalyst, the active metal content calculated as M is 10-20 wt%.

7. The method according to claim 1, wherein In step (1), the raw oil has a sulfur content of ≥3 wt%, an asphaltene content of ≥11 wt%, and a heavy metal content calculated as Ni and / or V of ≥150 ppm; And / or, the raw oil is selected from high-sulfur low-quality oil.

8. The method according to claim 7, wherein: The raw oil is selected from at least one of high-sulfur crude oil, high-sulfur deoiled asphalt and high-sulfur vacuum residue.

9. The method according to claim 1, wherein In step (1), the hydrodesulfurization treatment is carried out in a slurry bed reactor; And / or, the conditions of the hydrodesulfurization treatment include: temperature of 400-430°C; hydrogen partial pressure of 10-18 MPa; volume space velocity of 0.1-0.5h -1 ; The concentration of the catalyst calculated as metal element is 500-10000 μg / g.

10. The method according to claim 1, wherein In step (2), the separation method is selected from filtration separation, centrifugal separation, and solvent extraction separation.

11. The method according to claim 10, wherein: The solvent extraction separation process includes: contacting the liquid and solid components with a solvent and performing the solvent extraction separation; And / or, the conditions for the solvent extraction separation include: temperature of 40-300° C.; pressure of 0.1-6 MPa; And / or, the amount of the solvent used is 1-10 parts by weight relative to 1 part by weight of the desolidified oil.

12. The method according to claim 11, wherein The conditions for the solvent extraction separation include: temperature of 80-240°C; pressure of 0.1-3 MPa; and / or, the amount of the solvent is 1-5 parts by weight relative to 1 part by weight of the desolidified oil; and / or, the solvent is selected from at least one of C3-C8 alkanes, C3-C8 olefins, toluene and light naphtha; And / or, the temperature of the distillation cutting is 330-370°C; And / or, the heavy component satisfies: the heavy metal content calculated as Ni and / or V is ≤50ppm.

13. The method according to claim 12, wherein: The solvent is selected from C4-C5 alkanes and / or toluene.

14. The method according to claim 1, wherein In step (3), the low-sulfur petroleum coke satisfies the following requirements: sulfur content ≤ 3wt%, volatile matter content ≤ 12wt%, and ash content ≤ 0.5wt%; And / or, fractionating the gas-liquid mixture obtained from the coking process to obtain coking gas and coking distillate oil, wherein the coking distillate oil includes coking naphtha, coking diesel and coking wax oil.

15. The method according to any one of claims 1 to 14, wherein: The method further comprises: dividing the solid-containing tail oil component into two streams, roasting the first stream of the solid-containing tail oil component to obtain metal residue; and returning the second stream of the solid-containing tail oil component to undergo the hydrodesulfurization treatment.

16. The method according to claim 15, wherein The weight ratio of the first solid tail oil component to the second solid tail oil component is 0-100:100-0; And / or, the calcination conditions include: temperature of 400-600°C; time of 10-240min; And / or, the calcination is carried out in an oxygen-containing gas, and the oxygen-containing gas is selected from air and / or oxygen.

17. The method according to claim 16, wherein The weight ratio of the first solid tail oil component to the second solid tail oil component is 5-100:95-0; And / or, the calcination conditions include: a temperature of 450-550°C; The duration is 30-180 minutes; And / or, the feed ratio of the oxygen-containing gas to the solid tail oil-containing component, calculated as oxygen, is 20-150 mL / g.

18. The method according to claim 17, wherein The weight ratio of the first solid tail oil component to the second solid tail oil component is 90-100:10-0.

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