A method for producing chemical raw materials from vacuum residue

Abstract

The present invention discloses a method for producing chemical raw materials from vacuum residue. The method comprises: mixing the vacuum residue raw material with hydrogen and entering an ebullated bed hydrogenation reaction zone to carry out a hydrothermal cracking reaction, and separating and fractionating to obtain a gas fraction, a sideline oil, and a tail oil; wherein the mass content of aromatic hydrocarbons larger than three rings in the sideline oil is not higher than 1.0%; in the presence of hydrogen, the sideline oil enters a first hydrocracking reaction zone to obtain a first hydrocracking product; wherein, in the first hydrocracking product, C7 + The mass content of normal paraffins is controlled at 0.1% to 5.0%. The first hydrocracking product then enters a second hydrocracking reaction zone. The resulting second hydrocracking product is separated and fractionated to produce a gas fraction, light naphtha, heavy naphtha, and tail oil. This method, using vacuum residue as a feedstock, can significantly improve the yield and quality of chemical raw materials by combining ebullated-bed hydrogenation and hydrocracking to produce chemical raw materials.

Description

Technical Field

[0001] The present invention belongs to the field of heavy oil processing, and specifically relates to a method for producing chemical raw materials by combining ebullated bed residue oil hydrogenation and hydrocracking, in particular a processing method for producing high-quality chemical raw materials using vacuum residue oil as raw material. Background Art

[0002] In recent years, with the gradual decline in light crude oil resources and the continuous rise in its price, the global trend has shifted to processing low-quality heavy crude oil, which has abundant reserves, widespread availability, and low prices. Simultaneously, market demand for light oil products continues to increase, and environmental regulations on oil quality are becoming increasingly stringent. This situation has forced refineries to seriously address the global technical challenge of deep processing of low-quality heavy oil. Ebullating-bed residue hydrotreating technology can be used to process heavy crude oils with high sulfur, high carbon residue, and high metal content. It offers advantages such as uniform reactor temperature, long operating cycles, and flexible unit operation. It can address the problems of low space velocity, rapid catalyst deactivation, and large system pressure drop in fixed-bed residue hydrotreating units, offering significant advantages.

[0003] CN201580070326.4 discloses a method for preparing LPG and BTX, comprising: a) subjecting a mixed hydrocarbon stream to a first hydrocracking in the presence of a first hydrocracking catalyst to produce a first hydrocracked product stream; b) separating the first hydrocracked product stream to provide at least one light hydrocarbon stream comprising at least C2 and C3 hydrocarbons, an intermediate hydrocarbon stream consisting of C4 and / or C5 hydrocarbons, and a heavy hydrocarbon stream comprising at least C6+ hydrocarbons, and c) subjecting the heavy hydrocarbon stream to a second hydrocracking in the presence of a second hydrocracking catalyst to produce a second hydrocracked product stream comprising BTX, wherein the second hydrocracking is more severe than the first hydrocracking, d) wherein, in the presence of a C4 hydrocracking catalyst, at least a portion of the intermediate hydrocarbon stream is subjected to C4 hydrocracking to produce a C4 hydrocracking product stream, and the C4 hydrocracking is optimized for converting C4 hydrocarbons into C3 hydrocarbons.

[0004] CN201480037272.7 discloses a method for producing light olefin hydrocarbon compounds from hydrocarbon feedstocks, comprising the following steps: (a) feeding the hydrocarbon feedstock to a reaction zone for ring opening; (b) separating the reaction product produced by the reaction zone into an overhead stream and a side stream; (c) feeding the side stream from (b) to a gasoline hydrocracker (GHC) unit; (d) separating the reaction product of the GHC of step (c) into an overhead stream comprising hydrogen, methane, ethane and liquefied petroleum gas and a stream comprising aromatic hydrocarbon compounds and a small amount of hydrogen and non-aromatic hydrocarbon compounds; (e) feeding the overhead stream from the gasoline hydrocracker (GHC) unit to a steam cracker unit.

[0005] In summary, petroleum hydrocarbons have a complex composition, mainly including chain alkanes, cycloalkanes and aromatics, among which chain alkanes, especially small molecular chain alkanes, are high-quality ethylene raw materials, while cycloalkanes and aromatics are high-quality reforming feeds. Ebullated bed hydrogenation is to make heavy raw materials undergo hydrogenation thermal cracking reaction in a hydrogen environment, following the free radical reaction mechanism. Its products have high content of normal hydrocarbons and cyclic hydrocarbons. The existing technology for hydrogenating distillate oil from ebullated bed residue cannot efficiently achieve the conversion effect of "olefins as appropriate, aromatics as appropriate". Therefore, it is of great significance to develop a processing method suitable for producing high-quality chemical raw materials by using vacuum residue as raw material through ebullated bed hydrogenation and hydrocracking. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for producing chemical raw materials from vacuum residue oil. The method uses vacuum residue oil as raw material and can significantly improve the quality and yield of chemical raw materials.

[0007] The present invention provides a method for producing chemical raw materials from vacuum residue, the method comprising:

[0008] (1) mixing the vacuum residue feedstock with hydrogen and entering an ebullated bed hydrogenation reaction zone for hydrothermal cracking, and separating and fractionating to obtain a gas fraction, a side oil, and a tail oil; wherein the mass content of aromatic hydrocarbons larger than three rings in the side oil is not higher than 1.0%;

[0009] (2) In the presence of hydrogen, the sideline oil obtained in step (1) enters the first hydrocracking reaction zone to selectively crack the normal paraffins in the first hydrocracking product to obtain the first hydrocracking product; wherein, in the first hydrocracking product, C7 + The mass content of normal alkanes is controlled at 0.1% to 5.0%;

[0010] (3) in the presence of hydrogen, the first hydrocracking product enters a second hydrocracking reaction zone to obtain a second hydrocracking product containing monocyclic cyclic hydrocarbons;

[0011] (4) The second hydrocracking product is separated and fractionated to obtain gas fraction, light naphtha, heavy naphtha and tail oil.

[0012] According to the present invention, the properties of the vacuum residue in step (1) are as follows: an initial boiling point of 420° C. to 620° C., preferably 450° C. to 550° C.; a sulfur content by mass of 2% to 10%, preferably 4% to 8%; a nitrogen content by mass of 0.2% to 1.0%, preferably 0.3% to 0.5%; and a metal content of 100 mg / kg to 500 mg / kg, preferably 200 mg / kg to 300 mg / kg.

[0013] According to the present invention, the reaction conditions of the ebullated bed hydrogenation reaction zone in step (1) are as follows: reaction pressure of 10MPa to 25MPa, preferably 15MPa to 20MPa; reaction temperature of 350°C to 500°C, preferably 400°C to 450°C; hydrogen to oil volume ratio of 100:1 to 2000:1, preferably 300:1 to 1000:1; volume space velocity of 0.1h -1 ~1.5h -1 , preferably 0.2h -1 ~1.0h -1 .

[0014] According to the present invention, the conversion rate of the vacuum residue oil feedstock in the ebullated bed hydrogenation reaction zone in step (1) is controlled to be 60% to 90%, preferably 70% to 80%. The conversion rate is defined as the sum of the mass percentages of the gas fraction and the sideline oil in the ebullated bed hydrogenation product relative to the fresh feedstock.

[0015] According to the present invention, the initial boiling point of the ebullated bed sideline oil extracted in step (1) is 50-80°C, preferably 60-70°C; and the final boiling point is 400-600°C, preferably 450-550°C.

[0016] According to the present invention, the mass content of aromatic hydrocarbons larger than three rings in the ebullated bed sideline oil extracted in step (1) is 0.2% to 0.6%.

[0017] According to the present invention, preferably, in step (2), C7 + The mass content of normal alkanes is controlled at 1.0% to 3.0%.

[0018] According to the present invention, the chemical raw materials include light olefin raw materials and reforming raw materials. Specifically, the chemical raw materials primarily include ethane, propane, butane, and light naphtha, and may also include heavy naphtha. Heavy naphtha is used as a reforming raw material to produce BTX, while ethane, propane, butane, and light naphtha are used as raw materials for producing light olefins, such as steam cracking raw materials to produce ethylene. Propane and butane can also be directly dehydrogenated to produce propylene and butene. Light olefins refer to olefins with a carbon content of four or less, particularly ethylene, propylene, and butadiene.

[0019] According to the present invention, the side-drawn oil may contain impurities such as sulfur and nitrogen. If necessary, a hydrotreating catalyst may be installed upstream of the first hydrocracking catalyst to remove impurities such as sulfur and nitrogen. The nitrogen content of the reactant stream in contact with the first hydrocracking catalyst is preferably less than 50 mg / kg, more preferably less than 20 mg / kg.

[0020] According to the present invention, in step (2), the first hydrocracking reaction zone is loaded with a first hydrocracking catalyst, which may be one or more catalysts. In step (2), the first hydrocracking catalyst comprises an active metal component and a carrier; the carrier comprises a molecular sieve having the ability to selectively crack normal alkanes, preferably one or more selected from ZSM-5 molecular sieve, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, and ZSM-38 molecular sieves, preferably ZSM-5 molecular sieve. The SiO2 / Al2O3 molar ratio of the ZSM-5 molecular sieve is 20 to 60. The carrier may further comprise a binder. Preferably, the binder is alumina. The active metal component comprises at least one of a metal from Group VIB and a metal from Group VIII, the metal from Group VIB preferably being molybdenum and / or tungsten, and the metal from Group VIII preferably being cobalt and / or nickel.

[0021] According to the present invention, in step (2), preferably, the first hydrocracking catalyst has, based on the weight of the catalyst, a content of Group VIB metal (calculated as oxide) of 5.0% to 15.0%, a content of Group VIII metal (calculated as oxide) of 2.0% to 5.0%, and a content of the carrier of 80.0% to 93.0%.

[0022] According to the present invention, in step (2), preferably, in the carrier of the first hydrocracking catalyst, the content of the binder is 8% to 60%, and the content of the molecular sieve is 40% to 92%, based on the weight of the carrier.

[0023] According to the present invention, in step (2), the specific surface area of the first hydrocracking catalyst is 200 to 400 m 2 / g, pore volume is 0.25~0.45cm 3 The particle size of the second hydrocracking catalyst is 1.0 to 3.0 μm.

[0024] According to the present invention, the preparation method of the first hydrocracking catalyst in step (2) can be prepared according to conventional methods in the art. The preparation method includes preparing a carrier and loading the active metal component, wherein the carrier preparation process is as follows: mechanically mixing the shape-selective cracking molecular sieve and the binder, forming, and then drying and calcining to form a catalyst carrier. The drying and calcining of the carrier can adopt conventional conditions. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcining conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0025] According to the present invention, in step (2), in the preparation method of the first hydrocracking catalyst, the method for loading the active metal component is a conventional method, such as a kneading method, an impregnation method, etc., preferably an impregnation method. The impregnation method can be a saturation impregnation method, an excess impregnation method, or a complex impregnation method, that is, the catalyst support is impregnated with a solution containing the desired active component, and then dried and calcined to obtain the second hydrocracking catalyst. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcination conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0026] According to the present invention, the reaction conditions of the first hydrocracking reaction zone in step (2) are as follows: the reaction pressure is 15 to 18 MPa, preferably 16 to 17 MPa.

[0027] According to the present invention, the reaction conditions of the first hydrocracking reaction in step (2) are as follows: the average reaction temperature is 250-450°C, preferably 300-400°C; the liquid hourly volume space velocity is 0.1-15.0h -1 , preferably 1.0~5.0h -1 ; The volume ratio of hydrogen to oil is 100:1 to 2500:1, preferably 400:1 to 2000:1.

[0028] According to the present invention, in step (3), the second hydrocracking reaction zone is loaded with a second hydrocracking catalyst, which can be one or more catalysts.

[0029] According to the present invention, the ratio of the mass of C6-C8 monocyclic cyclic hydrocarbons in the second hydrocracking product of step (3) to the mass of the total cyclic hydrocarbons in the sideline oil feedstock is 0.20-0.40, preferably 0.31-0.36.

[0030] According to the present invention, the second hydrocracking catalyst in step (3) has the function of ring-opening cracking of polycyclic cyclic hydrocarbons, selectively cracking the side chains of isomeric hydrocarbons or cyclic hydrocarbons and retaining the function of monocyclic cyclic hydrocarbons. The second hydrocracking catalyst includes a cracking component, a hydrogenation component and a binder. The second hydrocracking catalyst can be commercially available or prepared according to existing technology. The hydrogenation component is at least one of the metal, metal oxide, and metal sulfide of the active metal component; the active metal component includes VIB and / or VIII group metals; the active metal component is more preferably at least one of iron, chromium, molybdenum, tungsten, cobalt, and nickel. In the second hydrocracking catalyst, the binder is alumina and / or silica; the cracking component includes an acidic molecular sieve, preferably at least one of Beta molecular sieve and Y molecular sieve.

[0031] According to the present invention, preferably, in step (3), the second hydrocracking reaction zone is sequentially loaded with a catalyst with a Y molecular sieve as a cracking component and a catalyst with a Beta molecular sieve as a cracking component along the direction of material flow; preferably, the volume ratio of the catalyst with a Y molecular sieve as a cracking component to the catalyst with a Beta molecular sieve as a cracking component is 5:1 to 1:2, preferably 3:1 to 1:1.

[0032] According to the present invention, the second hydrocracking catalyst in step (3) has a hydrogenation component content of 5 wt% to 40 wt%, preferably 10 wt% to 30 wt%, calculated as oxide, based on the weight of the second hydrocracking catalyst; a cracking component content of 10 wt% to 80 wt%, preferably 20 wt% to 60 wt%; and a binder content of 5 wt% to 85 wt%, preferably 10 wt% to 50 wt%.

[0033] According to the present invention, the preparation method of the second hydrocracking catalyst in step (3) can be prepared according to conventional methods in the art. The preparation method includes preparing a carrier and loading the hydrogenation component, wherein the carrier preparation process is as follows: the cracking component and the binder are mechanically mixed, formed, and then dried and calcined to form a catalyst carrier. The drying and calcination of the carrier can adopt conventional conditions. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcination conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0034] According to the present invention, in step (3), in the preparation method of the second hydrocracking catalyst, the method for loading the hydrogenation component is a conventional method, such as a kneading method, an impregnation method, etc., preferably an impregnation method. The impregnation method can be a saturation impregnation method, an excess impregnation method, or a complex impregnation method, that is, the catalyst support is impregnated with a solution containing the desired hydrogenation component, and then dried and calcined to obtain the second hydrocracking catalyst. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcination conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0035] According to the present invention, the reaction conditions of the second hydrocracking reaction zone in step (3) are as follows: the reaction pressure is 15 to 18 MPa, preferably 16 to 17 MPa.

[0036] According to the present invention, the reaction conditions of the second hydrocracking reaction zone in step (3) are as follows: the average reaction temperature is 250-450°C, preferably 300-400°C; the liquid hourly volume space velocity is 0.1-15.0h -1 , preferably 1.0~5.0h -1 ; The volume ratio of hydrogen to oil is 100:1 to 2500:1, preferably 400:1 to 2000:1.

[0037] According to the present invention, preferably, the first hydrocracking reaction zone and the second hydrocracking reaction zone adopt the same pressure.

[0038] According to the present invention, preferably, the second hydrocracking reaction effluent in step (3) is subjected to supplementary hydrofining. The supplementary hydrofining can be performed by loading a hydrofining catalyst at the bottom of the second hydrocracking reaction zone, or entering a separate hydrofining reaction zone.

[0039] According to the present invention, preferably, the effluent from the second hydrocracking reaction in step (3) may also first enter a fractionation system, and the separated heavy naphtha component may be subjected to supplementary hydrorefining.

[0040] According to the present invention, the tail oil obtained in step (3) is circulated to the second hydrocracking reaction zone.

[0041] Petroleum hydrocarbons are complex, primarily comprising paraffins, cycloalkanes, and aromatics. High-quality ethylene feedstocks are small-molecule normal alkanes, while reforming feedstocks are monocyclic cycloalkanes and aromatics. The inventors discovered through research that the technical solution of the present invention can maximize the retention of monocyclic cyclic hydrocarbons and produce small-molecule normal alkanes with high selectivity, thereby achieving efficient enrichment of small-molecule normal alkanes in light olefin feedstocks. Simultaneously, it maximizes the retention of monocyclic cyclic hydrocarbons in heavy naphtha, thereby achieving efficient enrichment of high-quality reforming feedstocks. This significantly improves the yield and quality of chemical feedstocks (i.e., ethylene feedstock and reforming feedstock), thereby completing the present invention.

[0042] Compared with the prior art, the present invention has the following beneficial technical effects:

[0043] (1) In the prior art, when ebullated bed wax oil is used as a raw material for hydrocracking to produce chemical raw materials, the final boiling point of the ebullated bed wax oil obtained by separation in the fractionation tower is generally 520-560°C, resulting in a high content of aromatic hydrocarbons larger than three rings in the wax oil fraction. A higher reaction pressure is required to achieve hydrocracking of three ring aromatics. However, a higher reaction pressure will also cause some monocyclic aromatic hydrocarbons to undergo ring-opening cracking during the hydrocracking process, resulting in loss of aromatic hydrocarbons. In the combined processing method of the present invention, by controlling the content of aromatic hydrocarbons larger than three rings in the ebullated bed full fraction wax oil to be no more than 1%, a suitable reaction pressure is selected to achieve mixed processing of aromatic hydrocarbons smaller than three rings, thereby reducing the loss of aromatic hydrocarbons in the raw material during the hydrogenation process and increasing the aromatic hydrocarbon content in the hydrogenated product. The side-line oil and hydrogen enter the first hydrocracking reaction zone, mainly to selectively crack the normal alkanes and the long straight-chain isoalkanes and cycloalkanes containing long straight chains in the raw material to generate small molecular normal alkanes, so that the C7 +The content of normal alkanes is between 0.1% and 5.0%. The effluent from the normal hydrocarbon conversion reaction enters the second hydrocracking reaction zone, which mainly performs ring-opening cracking of polycyclic cyclic hydrocarbons while retaining monocyclic cyclic hydrocarbons and further breaks the side chains of each hydrocarbon to generate small molecular hydrocarbons. In this way, a large amount of chain alkanes in the feedstock can be converted into gas and light naphtha components, that is, enriched in the ethylene feedstock, while monocyclic cyclic hydrocarbons are retained in the heavy naphtha fraction, that is, enriched in the reforming feedstock. Through simple fractional distillation, efficient separation of chain alkanes and cyclic hydrocarbons can be achieved, thereby increasing the production of high-quality ethylene cracking feed and improving the quality of heavy naphtha as catalytic reforming feed.

[0044] (2) The heavy naphtha obtained by the method of the present invention has a high content of monocyclic cyclic hydrocarbons. When used as feed for a catalytic reforming unit, the cyclization and dehydrogenation units of the paraffins in the catalytic reforming unit can be eliminated, thereby significantly reducing the investment and energy consumption of the catalytic reforming unit. At the same time, since the hydrocracking reaction follows the positive carbon ion reaction mechanism, the cyclic hydrocarbons above C9 can be selectively subjected to side chain scission reactions, so that the C6-C8 cyclic hydrocarbons in the product have a high enrichment degree. After catalytic reforming and aromatics extraction, the BTX yield can be significantly increased.

[0045] (3) The present invention selectively converts the chain alkanes in the side-line oil into small-molecule alkanes. This process consumes a certain amount of hydrogen, but the hydrogen yield of light hydrocarbons as raw materials for ethylene plants is also high. The lower the carbon number, the higher the hydrogen yield. Therefore, most of the hydrogen consumed in the hydrogenation process can be recovered after passing through the ethylene plant. At the same time, light hydrocarbons as ethylene raw materials can greatly increase the yields of ethylene, propylene and butadiene, and extend the rubber cleaning cycle of the ethylene plant, significantly improving the economic benefits of the plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the process flow of Examples 1 to 4 of the present invention;

[0047] Description of main reference numerals:

[0048] 1-vacuum residue, 2-hydrogen, 3-ebullated-bed hydrogenation reaction zone, 4-ebullated-bed hydrogenation reaction effluent, 5-separator, 6-gas stream, 7-liquid stream, 8-fractionation tower, 9-gas fraction, 10-sideline oil, 11-tail oil, 12-hydrogen, 13-first hydrocracking reaction zone, 14-first hydrocracking reaction effluent, 15-second hydrocracking reaction zone, 16-second hydrocracking reaction effluent, 17-separator, 18-gas stream hydrogen-rich gas, 19-liquid stream, 20-fractionation tower, 21-gas fraction, 22-light naphtha, 23-heavy naphtha, 24-tail oil. DETAILED DESCRIPTION

[0049] The effects and benefits of the present invention are further illustrated below by way of examples, but the following examples do not constitute a limitation to the method of the present invention.

[0050] Unless otherwise specified, % in the present invention refers to mass fraction.

[0051] The total volume space velocity in the Examples and Comparative Examples is the ratio of the volume of fresh feed to the total volume of the catalyst.

[0052] The method of the present invention, such as Figure 1 As shown, it includes: vacuum residue oil 1 is mixed with hydrogen 2 and enters an ebullated bed hydrogenation reaction zone 3, the obtained ebullated bed hydrogenation reaction effluent 4 enters a separator 5, the separated gaseous phase stream 6 is recycled, the liquid phase stream 7 enters a fractionating tower 8, and is fractionated to obtain a gas fraction 9, a sideline oil 10 and a tail oil 11, the sideline oil 10 is mixed with hydrogen 12 and enters a first hydrocracking reaction zone 13 for a first hydrocracking reaction, the first hydrocracking reaction effluent 14 enters a second hydrocracking reaction zone 15 for a second hydrocracking reaction, the second hydrocracking reaction effluent 16 enters a separator 17, the separated gaseous phase stream hydrogen-rich gas 18 is recycled, the liquid phase stream 19 enters a fractionating tower 20, and is fractionated to obtain a gas fraction 21, light naphtha 22, heavy naphtha 23 and tail oil 24, and the tail oil 24 is recycled to the second hydrocracking reaction zone 15.

[0053] In the present invention, the first hydrocracking catalyst in each example is represented by Cat-A plus a number, such as Cat-A1, Cat-A2, Cat-A3, and Cat-A4. The first hydrocracking catalyst is prepared by a conventional active metal saturation impregnation method. The physicochemical properties of the obtained catalyst are shown in Table 1.

[0054] In the present invention, the second hydrocracking catalyst in each example is represented by Cat-B plus a number, such as Cat-B1 and Cat-B2. The physicochemical properties of the catalyst are shown in Table 2. The second hydrocracking catalyst in each example is prepared by a conventional active metal saturation impregnation method. The properties of the Beta molecular sieve used in Cat-B2 are as follows: SiO2 / Al2O3 molar ratio of 30, specific surface area of 350m 2 / g, pore volume is 0.32cm 3 / g, the properties of the Y molecular sieve used in Cat-B1 are as follows: SiO2 / Al2O3 molar ratio is 15, specific surface area is 400m 2 / g, pore volume is 0.30cm 3 / g.

[0055] In the present invention, the raw oil in each example is vacuum residue raw material, and its main properties are shown in Table 3.

[0056] In the present invention, the nitrogen content in the reactant stream contacting the first hydrocracking catalyst in each example was 20 mg / kg.

[0057] In the present invention, the ethylene raw materials in each example refer to the ethane, propane, butane and light naphtha obtained in step (3). Ethane, propane, butane and light naphtha can be directly used as raw materials for steam cracking to produce ethylene.

[0058] In the present invention, the distillation range of light naphtha is the liquid component less than 60°C, the distillation range of heavy naphtha is 60-175°C, and the distillation range of tail oil is the component greater than 175°C.

[0059] In the present invention, the yield of ethylene feedstock refers to the mass ratio of ethane, propane, butane and light naphtha in the hydrocracking products to the fresh hydrocracking feedstock (sideline oil), and the yield of heavy naphtha refers to the mass ratio of heavy naphtha in the hydrocracking products to the fresh hydrocracking feedstock (sideline oil).

[0060] Examples 1 to 4

[0061] This example method uses Figure 1 Process, including:

[0062] (1) Vacuum residue oil is mixed with hydrogen and enters an ebullated bed hydrogenation reaction zone for hydrothermal cracking reaction. The resulting ebullated bed hydrogenation reaction effluent enters a separator, the separated gaseous stream is recycled, and the liquid stream enters a fractionating tower for fractionation to obtain a gas fraction, sideline oil, and tail oil;

[0063] (2) The sideline oil is mixed with hydrogen and enters the first hydrocracking reaction zone and the second hydrocracking reaction zone in sequence; the first hydrocracking reaction zone is filled with a first hydrocracking catalyst; the second hydrocracking reaction zone is filled with a second hydrocracking catalyst; the C7 + The content of normal paraffins and the content of polycycloparaffins in the second hydrocracked product.

[0064] (3) The reaction effluent of the second hydrocracking reaction zone is subjected to gas-liquid separation to obtain a gas phase flow and a liquid phase flow; wherein the gas phase flow is recycled, and the liquid phase flow enters a distillation tower for fractionation to obtain a gas fraction, light naphtha, heavy naphtha and tail oil; and the tail oil is recycled to the second hydrocracking reaction zone.

[0065] The process conditions and hydrogenation effects of each case are shown in Table 5.

[0066] Comparative Example 1

[0067] The difference from Example 1 is that the side-line oil is directly fed into the second hydrocracking reaction zone after being hydrotreated.

[0068] The process conditions and hydrogenation effects in this example are shown in Table 5.

[0069] Comparative Example 2

[0070] The difference from Example 1 is that in step (1), the C7 + The normal alkane content is 6%.

[0071] The process conditions and hydrogenation effects in this example are shown in Table 5.

[0072] Comparative Example 3

[0073] The difference from Example 1 is that the catalyst loading order in the second hydrocracking reaction zone is different from that in Example 1. In this example, the order of catalysts Cat-B1 and Cat-B2 is swapped. Specifically, the hydrocracking reaction zone in this example is loaded with catalysts Cat-B2 and Cat-B1 in the order along the direction of material flow.

[0074] The process conditions and hydrogenation effects in this example are shown in Table 5.

[0075] Comparative Example 4

[0076] The difference from Example 1 is that the mass content of aromatic hydrocarbons larger than three rings in the side-drawn oil is 3.2%.

[0077] The process conditions and hydrogenation effects in this example are shown in Table 5.

[0078] Table 1 Physicochemical properties of the first hydrocracking catalyst

[0079]

[0080]

[0081] Table 2 Physicochemical properties of the second hydrocracking catalyst

[0082] Catalyst properties Cat-B1 Cat-B2 <![CDATA[Pore volume, cm 3 / g]]> 0.35 0.35 <![CDATA[Specific surface area, m 2 / g]]> 300 300 Catalyst composition and content Beta, wt% - 50 Y, wt% 30 - <![CDATA[MoO3,wt%]]> 25 10 NiO, wt% 5 5 Alumina, wt% 40 35

[0083] Table 3 Main properties of crude oil

[0084] Raw oil name Vacuum residue <![CDATA[Density (20 °C) / kg·m -3 > 1.032 Distillation range / ℃ IBP / 10% 464 / 558 30％ / 50％ 606 / 646 70％ / 90％ 749 / 973 95% / EBP 1025 / 1055 Sulfur content, wt% 5.61 Nitrogen content, wt% 0.38 Ni+V, mg / kg 200

[0085] Table 4 Ebullated bed hydrogenation process conditions and main properties of side-drawn oil

[0086]

[0087]

[0088] Table 4

[0089]

[0090] Table 5 Hydrogenation effect

[0091]

[0092]

[0093] Table 5

[0094]

[0095] The above describes in detail the specific embodiments of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for producing chemical raw materials from vacuum residue, characterized in that: The method comprises: (1) The vacuum residue feedstock is mixed with hydrogen and enters the ebullated bed hydrogenation reaction zone for hydrothermal cracking reaction, and the gas fraction, sideline oil and tail oil are obtained through separation and fractionation; wherein the mass content of aromatic hydrocarbons larger than three rings in the sideline oil is not higher than 1.0%; (2) In the presence of hydrogen, the sideline oil obtained in step (1) enters the first hydrocracking reaction zone to selectively crack the normal paraffins in the first hydrocracking product to obtain the first hydrocracking product; wherein, in the first hydrocracking product, C7 + The mass content of normal alkanes is controlled at 0.1%~5.0%; (3) the first hydrocracking product enters a second hydrocracking reaction zone in the presence of hydrogen to obtain a second hydrocracking product containing monocyclic cyclic hydrocarbons; (4) The second hydrocracking product is separated and fractionated to obtain gas fraction, light naphtha, heavy naphtha and tail oil; In step (2), the first hydrocracking reaction zone is loaded with a first hydrocracking catalyst; the first hydrocracking catalyst comprises an active metal component and a carrier; the carrier comprises a molecular sieve having the ability to selectively crack normal alkanes, the molecular sieve being selected from one or more of ZSM-5 molecular sieve, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-38 molecular sieves; the active metal component comprises at least one of a Group VIB metal and a Group VIII metal; The first hydrocracking catalyst has a content of 5.0% to 15.0% of the Group VIB metal as oxide, 2.0% to 5.0% of the Group VIII metal as oxide, and 80.0% to 93.0% of the carrier, based on the weight of the catalyst; In step (3), the second hydrocracking reaction zone is loaded with a second hydrocracking catalyst; the second hydrocracking catalyst comprises a cracking component, a hydrogenation component and a binder; In step (3), the second hydrocracking reaction zone is sequentially loaded with a catalyst having a Y molecular sieve as a cracking component and a catalyst having a Beta molecular sieve as a cracking component along the direction of material flow; The second hydrocracking reaction zone has a hydrogenation component content of 5 wt% to 40 wt% in terms of oxides, a cracking component content of 10 wt% to 80 wt% and a binder content of 5 wt% to 85 wt% based on the weight of the second hydrocracking catalyst. The chemical raw materials include ethane, propane, butane, light naphtha and heavy naphtha, wherein heavy naphtha is used as a reforming raw material to produce BTX, and ethane, propane, butane and light naphtha are used as raw materials to produce low-carbon olefins.

2. The method according to claim 1, characterized in that The properties of the vacuum residue in step (1) are as follows: initial distillation point of 420° C. to 620° C.; sulfur content by mass of 2% to 10%; nitrogen content by mass of 0.2% to 1.0%; and metal content of 100 mg / kg to 500 mg / kg.

3. The method according to claim 1, characterized in that The properties of the vacuum residue in step (1) are as follows: initial distillation point of 450° C. to 550° C.; sulfur content by mass of 4% to 8%; nitrogen content by mass of 0.3% to 0.5%; and metal content of 200 mg / kg to 300 mg / kg.

4. The method according to claim 1, characterized in that The reaction conditions of the ebullated bed hydrogenation reaction zone in step (1) are as follows: reaction pressure of 10 MPa to 25 MPa; reaction temperature of 350°C to 500°C; hydrogen to oil volume ratio of 100:1 to 2000:1; volume space velocity of 0.1 h -1 ~1.5h -1 ; And / or, the ebullated bed hydrogenation reaction zone controls the conversion rate of the vacuum residue to be 60% to 90%; the conversion rate is the sum of the mass percentages of the gas fraction and the side-line oil in the ebullated bed hydrogenation product relative to the fresh feedstock.

5. The method according to claim 1, characterized in that: The reaction conditions of the ebullated bed hydrogenation reaction zone in step (1) are as follows: reaction pressure of 15 MPa to 20 MPa; reaction temperature of 400°C to 450°C; hydrogen to oil volume ratio of 300:1 to 1000:1; volume space velocity of 0.2 h -1 ~1.0h -1 ; And / or, the ebullated bed hydrogenation reaction zone controls the conversion rate of the vacuum residue to 70% to 80%; the conversion rate is the sum of the mass percentages of the gas fraction and the side-line oil in the ebullated bed hydrogenation product relative to the fresh feedstock.

6. The method according to claim 1, characterized in that The initial boiling point of the oil extracted from the ebullated bed sideline in step (1) is 50-80°C; the final boiling point is 400-600°C; And / or, the mass content of aromatic hydrocarbons larger than three rings in the ebullated bed sideline oil is 0.2% to 0.6%.

7. The method according to claim 1, characterized in that: The initial boiling point of the oil extracted from the ebullated bed side line in step (1) is 60-70°C; the final boiling point is 450-550°C.

8. The method according to claim 1, characterized in that: In the first hydrocracking catalyst, the molecular sieve is ZSM-5 molecular sieve; the Group VIB metal is molybdenum and / or tungsten; and the Group VIII metal is cobalt and / or nickel.

9. The method according to claim 1, characterized in that: In step (2), the reaction pressure of the first hydrocracking reaction zone is 15-18 MPa.

10. The method according to claim 1, characterized in that: In step (2), the reaction pressure of the first hydrocracking reaction zone is 16-17 MPa.

11. The method according to claim 1, characterized in that: The reaction conditions of the first hydrocracking reaction zone in step (2) are as follows: average reaction temperature of 250-450°C; liquid hourly volume space velocity of 0.1-15.0h -1 ;The volume ratio of hydrogen to oil is 100:1~2500:

1.

12. The method according to claim 1, characterized in that: The reaction conditions of the first hydrocracking reaction zone in step (2) are as follows: average reaction temperature of 300-400°C; liquid hourly volume space velocity of 1.0-5.0h -1 ;The volume ratio of hydrogen to oil is 400:1~2000:

1.

13. The method according to claim 1, characterized in that: C7 in step (2) + The mass content of normal alkanes is controlled at 1wt%~3wt%.

14. The method according to claim 1, wherein: The second hydrocracking catalyst has a hydrogenation component content of 10 wt% to 30 wt% in terms of oxides, a cracking component content of 20 wt% to 60 wt% and a binder content of 10 wt% to 50 wt% based on the weight of the second hydrocracking catalyst. and / or, in the second hydrocracking catalyst, the hydrogenation component is at least one of a metal, a metal oxide, and a metal sulfide of an active metal component; the active metal component comprises a Group VIB and / or Group VIII metal; And / or, in the second hydrocracking catalyst, the binder is alumina and / or silica.

15. The method according to claim 14, characterized in that: In the second hydrocracking catalyst, the active metal component is at least one of iron, chromium, molybdenum, tungsten, cobalt and nickel.

16. The method according to claim 1, wherein: The volume ratio of the second hydrocracking catalyst, the catalyst with Y molecular sieve as the cracking component and the catalyst with Beta molecular sieve as the cracking component, is 5:1 to 1:

2.

17. The method according to claim 1, characterized in that: The volume ratio of the second hydrocracking catalyst, the catalyst with Y molecular sieve as the cracking component and the catalyst with Beta molecular sieve as the cracking component, is 3:1 to 1:

1.

18. The method according to claim 1, wherein: The reaction pressure of the second hydrocracking reaction zone in step (3) is 15-18 MPa.

19. The method according to claim 1, wherein: The reaction pressure of the second hydrocracking reaction zone in step (3) is 16-17 MPa.

20. The method according to claim 1, wherein: The reaction conditions of the second hydrocracking reaction zone in step (2) are as follows: average reaction temperature of 250-450°C; liquid hourly volume space velocity of 0.1-15.0h -1 ;The volume ratio of hydrogen to oil is 100:1~2500:

1.

21. The method according to claim 1, wherein: The reaction conditions of the second hydrocracking reaction zone in step (2) are as follows: average reaction temperature of 300-400°C; liquid hourly volume space velocity of 1.0-5.0h -1 ;The volume ratio of hydrogen to oil is 400:1~2000:

1.

22. The method according to claim 1, wherein: The first hydrocracking reaction zone and the second hydrocracking reaction zone use the same pressure.

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