Conversion method and system of sulfur-containing raw material hydrocarbon

Abstract

The invention relates to a conversion method and system for sulfur-containing raw hydrocarbon. The invention relates to a method for converting sulfur-containing feedstock hydrocarbon. Comprising the following steps: 1) providing a sulfur-containing feedstock hydrocarbon wherein the feedstock hydrocarbon has a sulfur content of 50-5000 mg / kg, based on the total weight of the feedstock hydrocarbon, 2) chemically converting the sulfur-containing feedstock hydrocarbon to obtain a sulfur-containing conversion product, and 3) steam cracking the sulfur-containing conversion product to obtain a cracking product comprising ethylene. According to the invention, the sulfide in the raw material can be effectively converted into hydrogen sulfide, and the hydrogen sulfide is selectively retained in the conversion product, and when the conversion product is used as the ethylene raw material, the sulfur injection amount can be reduced and even the sulfur injection can be canceled, so that the high-value utilization of valuable components is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical engineering, and in particular to a method and system for converting sulfur-containing raw hydrocarbons. Background Art

[0002] In the production process of the ethylene plant, a series of complex chemical reactions will occur after the raw materials are cracked at high temperature, resulting in varying degrees of coking on the inner wall of the furnace tube of the radiation section of the cracking furnace and the inner wall of the quench boiler casing. As the coke layer continues to thicken, the heat transfer resistance of the furnace tube increases, and the heat outside the tube cannot be transferred to the cracked raw materials in the tube in time, which seriously affects the cracking depth of the raw materials. In addition, the temperature of the outer surface of the furnace tube continues to rise, and local overheating may occur, resulting in a shortened life of the furnace tube. When the temperature exceeds the maximum design temperature of the furnace tube material, the furnace needs to be stopped and the coke removed. Therefore, if the ethylene raw material does not contain or contains a low level of sulfide, sulfur needs to be injected during the reaction to prevent coking of the furnace tube; if the ethylene raw material contains a certain amount of sulfide, sulfur needs to be injected during the reaction to reduce the operating cost of the device.

[0003] With the rapid development of my country's chemical industry, the production capacity of ethylene has increased year by year. Therefore, the demand for ethylene raw materials has also continued to increase. How to broaden the selection range of ethylene raw materials and how to obtain high-quality ethylene raw materials have become urgent issues that need to be solved in the development of the ethylene industry. Summary of the invention

[0004] The inventors of the present invention have found that the ethylene raw material obtained through the hydrogenation process will remove the organic sulfur in the raw material and convert it into hydrogen sulfide during the hydrogenation reaction, and remove the hydrogen sulfide during the product separation process. Therefore, the sulfur content in the ethylene raw material is usually low, and sulfur injection is required before entering the ethylene cracking furnace to prevent coking of the furnace tube. If a portion of hydrogen sulfide is retained in the hydrogenation product during the separation process, when the hydrogenation product is used as an ethylene raw material, sulfur injection before entering the ethylene cracking furnace can be reduced or even unnecessary, and high-value utilization of waste gas can be achieved.

[0005] Specifically, the present invention relates to the following aspects.

[0006] 1. A method for converting a sulfur-containing hydrocarbon feedstock, comprising the following steps:

[0007] 1) providing a sulfur-containing feedstock hydrocarbon, wherein the sulfur content of the feedstock hydrocarbon is 50-5000 mg / kg (preferably 200-1000 mg / kg), relative to the total weight of the feedstock hydrocarbon,

[0008] 2) chemically converting the sulfur-containing feed hydrocarbon to obtain a sulfur-containing conversion product, and

[0009] 3) Steam cracking the sulfur-containing conversion product to obtain a cracking product containing ethylene.

[0010] 2. The conversion method according to claim 1, wherein the sulfur-containing feedstock hydrocarbon contains C 5 -C 6 The chemical conversion is to make at least a portion (such as more than 30wt%, more than 40wt%, more than 50wt%, more than 60wt%, more than 70wt%, more than 80wt% or more than 90wt% of the total amount) of the C 5 -C 6 Isoparaffin undergoes a conversion reaction in the presence of hydrogen, and the conversion product comprises C 2 -C 6 Normal alkanes.

[0011] 3. The conversion method according to any one of the preceding or following aspects, wherein the initial distillation point of the sulfur-containing feedstock hydrocarbon is 10-30°C (preferably 15-25°C) and the final distillation point is 50-100°C (preferably 55-70°C).

[0012] 4. The conversion method according to any one of the preceding or following aspects, wherein the sulfur-containing feedstock hydrocarbon contains C 7+ The content of hydrocarbon is 0-10wt% (preferably 0.5-5wt%), C 5 -C 6 The content of isoparaffin is 50wt% or more (preferably 60-90wt%, more preferably 70-80wt%), C 5 -C 6 The content of normal alkanes is 10-30wt% (preferably 15-25wt%), C 4 -hydrocarbon content is 0-10wt% (preferably 2-5wt%), cyclic hydrocarbon content is 1-10wt% (preferably 2-5wt%), sulfur content is 50-5000mg / kg (preferably 200-1000mg / kg), based on the total weight of the raw hydrocarbon as 100wt%, and / or C 7 + hydrocarbon content is not higher than 5wt% (preferably not higher than 1wt%), C 5 -C 6 The content of isoparaffin is 0-50wt% (preferably 10-40wt%), C 2 -C 6 The content of normal alkanes is 40-90wt% (preferably 50-80wt%), the content of cyclic hydrocarbons is not higher than 3wt% (preferably not higher than 1wt%), and the sulfur content is 50-1000mg / kg (preferably 100-200mg / kg), based on the total weight of the conversion product being 100wt%.

[0013] 5. The conversion method according to any one of the preceding or following aspects, wherein the sulfur-containing feed hydrocarbon is a light naphtha component obtained by cracking a hydrocarbon oil feedstock (such as hydrocracking or catalytic cracking).

[0014] 6. The conversion method according to any one of the preceding or following aspects, wherein the conversion process needs to be carried out in the presence of a catalyst, and the catalyst comprises an acidic component and a hydrogenation component.

[0015] 7. The conversion method according to any of the preceding or following aspects, wherein the acidic component is a molecular sieve having shape-selective catalytic properties, preferably selected from one or more of mordenite, ZSM molecular sieve, SAPO molecular sieve and EU-1 molecular sieve, more preferably selected from one or more of mordenite and ZSM molecular sieve, particularly preferably selected from one or more of mordenite, ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, Beta molecular sieve and ZSM-38 molecular sieve, in particular selected from one or more of mordenite and ZSM-5 molecular sieve.

[0016] 8. The conversion method according to any of the preceding or following aspects, wherein the catalyst further comprises a binder (preferably alumina), and the content of the binder is 5-65wt% (preferably 10-35wt%) based on the weight of the catalyst.

[0017] 9. The conversion method according to any of the preceding or following aspects, wherein the hydrogenation component is selected from at least one of the metals of Group VIB and Group VIII, the metal of Group VIB is preferably molybdenum and / or tungsten, and the metal of Group VIII is preferably cobalt and / or nickel.

[0018] 10. A conversion method according to any of the preceding or subsequent aspects, wherein the content of the VIB Group metal (in terms of oxide) is 5.0-30.0 wt% (preferably 10-20 wt%), and the content of the VIII Group non-precious metal (in terms of oxide) is 0.5-15.0 wt% (preferably 3-10 wt%), based on the weight of the catalyst.

[0019] 11. The conversion method according to any one of the preceding or following aspects, wherein the content of the acidic component is 30-80 wt% (preferably 40-70 wt%) based on the weight of the catalyst.

[0020] 12. The conversion method according to any of the preceding or following aspects, wherein the specific surface area of ​​the catalyst is 200-400 m 2 / g, and the pore volume is 0.25-0.45mL / g.

[0021] 13. The conversion method according to any of the preceding or following aspects, wherein the reaction conditions of the conversion reaction include: a reaction pressure of 0.5-10.0 MPaG (preferably 2.0-8.0 MPaG or 2.0-5.0 MPaG), a reaction temperature of 250-500° C. (preferably 350-450° C.), a liquid hourly volume space velocity of 0.1-15.0 h -1 (Preferably 0.5-5.0h -1 ), the volume ratio of hydrogen to oil is 10:1-2500:1 (preferably 100:1-2000:1 or 100:1-1000:1).

[0022] 14. The conversion method according to any of the preceding or following aspects, wherein the operating conditions of the steam cracking include: reaction temperature 750-900°C, reaction pressure 0.1-0.5MPaG, water-oil mass ratio 0.2-0.6, and system sulfur content 100-200mg / kg.

[0023] 15. The method according to any of the preceding or following aspects further comprises the following steps:

[0024] Isolate the conversion product to obtain 2 -C 6 a separation stream that is primarily normal alkanes (e.g., more than 80 wt%, more than 90 wt%, or more than 95 wt%), and

[0025] The separated stream is steam cracked to obtain a cracking product comprising ethylene.

[0026] 16. The conversion method according to any of the preceding or following aspects, wherein the weight ratio of the separated stream to the raw hydrocarbon is 0.4-0.9:1 (preferably 0.5-0.8:1).

[0027] 17. The method according to any of the preceding or following aspects further comprises the following steps:

[0028] Isolate the conversion product to obtain 4 -C 6 A normal stream mainly composed of normal alkanes (e.g., more than 80 wt%, more than 90 wt%, or more than 95 wt% of the total amount) and / or a stream mainly composed of C 2 -C 3 A low-carbon stream mainly composed of hydrocarbons (e.g., more than 90 wt% or more than 95 wt% of the total amount), and

[0029] The normal stream and / or the low carbon stream are steam cracked to obtain a cracking product comprising ethylene.

[0030] 18. A system for converting sulfur-containing hydrocarbon feedstock, comprising the following units:

[0031] 1) a feedstock hydrocarbon supply unit, which is configured to provide a sulfur-containing feedstock hydrocarbon, wherein the sulfur content of the feedstock hydrocarbon is 50-5000 mg / kg (preferably 200-1000 mg / kg), relative to the total weight of the feedstock hydrocarbon,

[0032] 2) a feedstock hydrocarbon conversion unit configured to chemically convert the sulfur-containing feedstock hydrocarbon to obtain a sulfur-containing conversion product, and

[0033] 3) A steam cracking unit configured to steam crack the sulfur-containing conversion product to obtain a cracking product comprising ethylene.

[0034] Technical Effects

[0035] Compared with the prior art, the method and system provided by the present invention can achieve one of the following technical effects or a combination of all or part of them:

[0036] 1. In the process of steam cracking to produce ethylene, the sulfur content of the raw materials needs to be controlled to a certain level. If the sulfur content is too low, sulfur needs to be injected before the cracking furnace, otherwise it will accelerate the coking of the ethylene cracking furnace, affecting the operating cycle and cracking effect; if the sulfur content in the raw materials is too high, it will increase the operating cost of subsequent desulfurization. When producing ethylene raw materials through hydrogenation reaction, by processing the raw materials and controlling the appropriate sulfur content in the hydrogenation product, the sulfur content in the raw materials of the ethylene unit can be effectively controlled, and the sulfur injection amount of the ethylene cracking furnace can be reduced or even eliminated.

[0037] 2. During the hydrogenation reaction of raw hydrocarbons, organic sulfides will be converted into hydrogen sulfide, which is a worthless product for the hydrogenation unit and even needs to be removed by separation means such as stripping. The removed hydrogen sulfide also needs subsequent harmless treatment. When the hydrogenation product containing a certain amount of hydrogen sulfide is used as an ethylene raw material, the problem of ethylene sulfur injection can be solved, and the high-value utilization of useless components can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a process flow diagram of the process method of the present invention.

[0039] exist Figure 1 In the figure, 1-sulfur-containing hydrocarbon stream, 2-hydrogen, 3-hydrogenation reaction zone, 4-effluent from the hydroconversion reaction zone, 5-high-pressure separator, 6-gas phase stream hydrogen-rich gas, 7-liquid phase stream.

[0040] Figure 2 The figure is a process flow diagram of the process method of the present invention.

[0041] exist Figure 2In the figure, 1-sulfur-containing hydrocarbon stream, 2-hydrogen, 3-hydrogenation reaction zone, 4-hydrogenation reaction zone effluent, 5-high-pressure separator, 6-gas stream hydrogen-rich gas, 7-liquid stream, 8-fractionation tower, 9-gas product, 10-liquid product. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are described in detail below, but it should be pointed out that the protection scope of the present invention is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0043] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definitions in this specification shall prevail.

[0044] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0045] In the context of the present invention, all numerical values ​​for parameters (eg amounts or conditions) are to be understood as being modified in all instances by the term "about", regardless of whether "about" actually appears before the numerical value.

[0046] In the context of the present invention, unless otherwise specified, each device used in the present invention may use a structure conventionally selected in the art without any particular limitation.

[0047] In the context of the present invention, the measurement method of the initial boiling point and the final boiling point is in accordance with the ASTM D86 measurement method.

[0048] In the context of the present invention, the method for measuring sulfur content is in accordance with GB / T380.

[0049] In the context of the present invention, the term "C 2 -C 6 "Normal alkanes" refer to normal alkanes with carbon numbers from 2 to 6. It should be particularly clarified that, although there is no distinction between normal alkanes and isoalkanes for alkanes with carbon numbers from 2 to 3, for the convenience of description in the present invention, alkanes with carbon numbers from 2 to 3 are also regarded as normal alkanes. In addition, unless otherwise specified, when the present invention uses this term, it can refer to any one or more of the normal alkanes with carbon numbers from 2 to 6, and can also refer to all normal alkanes with carbon numbers from 2 to 6.

[0050] In the context of the present invention, cyclic hydrocarbons refer to hydrocarbons having a ring structure in their molecular structure, such as cycloalkanes and aromatic hydrocarbons.

[0051] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight and pressure is gauge pressure.

[0052] In the context of the present invention, any two or more technical solutions or aspects of the present invention may be arbitrarily combined, and the technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0053] According to the technical solution of the invention of this application, a method for converting sulfur-containing raw hydrocarbons is involved. According to the invention, during the hydrogenation reaction, a portion of the hydrogen sulfide generated by the reaction is retained in the hydrogenation product during the separation process, so that when the hydrogenation product is used as an ethylene raw material, sulfur injection before entering the ethylene cracking furnace can be reduced or even unnecessary, and high-value utilization of waste gas can be achieved.

[0054] According to the technical solution of the present invention, the method includes the step of providing a sulfur-containing feedstock hydrocarbon. According to the present invention, the sulfur-containing feedstock hydrocarbon can be manufactured by any method known in the art, as long as it meets the requirements of the present invention for the sulfur-containing feedstock hydrocarbon. As the manufacturing method of the sulfur-containing feedstock hydrocarbon, for example, hydrocracking, catalytic cracking or atmospheric and vacuum distillation can be cited. Preferably, the initial boiling point of the sulfur-containing feedstock hydrocarbon is 10-30°C (preferably 15-25°C), and the final boiling point is 50-100°C (preferably 55-70°C), and more preferably, the sulfur-containing feedstock hydrocarbon is a light naphtha component obtained by hydrocracking a hydrocarbon oil feedstock.

[0055] According to the present invention, the sulfur content of the raw hydrocarbon is 50-5000 mg / kg (preferably 200-1000 mg / kg), relative to the total weight of the raw hydrocarbon. The inventors of the present invention have found that too low a content in the raw material is likely to cause the hydrogenation catalyst to continuously lose sulfur during the reaction, and the valence state of the hydrogenation component changes, thereby causing the catalyst to be deactivated. At the same time, too low a sulfur content cannot transfer the sulfur in the raw material to the hydrogenation product, and cannot solve the sulfur injection problem of the ethylene unit; if the sulfur content in the raw material is too high, it will increase the difficulty of removing it by the hydrogenation reaction, especially for low-pressure reaction processes, the difficulty of hydrodesulfurization is greatly increased, and when excessive sulfides remain in the hydrogenation product and enter the ethylene unit, it will also cause the sulfur content of the ethylene product to increase, increasing the difficulty of subsequent removal.

[0056] According to the technical solution of the present invention, in order to make the technical effect of the present invention more excellent, it is preferred that the sulfur-containing raw hydrocarbon contains C 5 -C 6More preferably, the C 5 -C 6 The content of isoparaffins is generally above 50wt% (preferably 60-90wt%, more preferably 70-80wt%), based on the total weight of the raw material hydrocarbon being 100wt%. According to the present invention, the content of isoparaffins in the raw material hydrocarbon should be within a certain range. When the raw material with a lower isoparaffin content is directly used as an ethylene raw material, a higher ethylene product yield can also be obtained. Although the proportion of normal alkanes can be increased after conversion, the increase is limited; the raw material with a higher isoparaffin content is difficult to obtain, and cannot be directly obtained by conventional distillation, and requires a high energy consumption operation unit to obtain it.

[0057] According to the technical solution of the present invention, C 7+ There is no particular restriction on the content of hydrocarbons, but in order to make the technical effect of the present invention more excellent, the C 7+ The content of hydrocarbon is generally 0-10wt% (preferably 0.5-5wt%), based on the total weight of the raw hydrocarbon being 100wt%. 7+ Too high a hydrocarbon content results in the inclusion of complex macromolecular components in the raw material. These macromolecular components are difficult to enter the molecular sieve pores with shape-selective conversion function, and are difficult to be converted into the main target product of the present invention, normal alkanes, through the conversion process, which is disadvantageous to the present invention.

[0058] According to the technical solution of the present invention, C 5 -C 6 There is no particular restriction on the content of normal alkanes, but in order to make the technical effect of the present invention more excellent, the C 5 -C 6 The content of normal alkanes is generally 10-30wt% (preferably 15-25wt%), based on the total weight of the raw hydrocarbon being 100wt%. The inventors of the present invention have found that the conversion of isoalkanes in the raw hydrocarbon to normal alkanes is affected by the chemical reaction balance. If the content of normal hydrocarbons is too high, the chemical reaction balance will proceed in the reverse direction, i.e., normal alkanes will be converted into isoalkanes, which will affect the conversion effect of isoalkanes and is not beneficial to the present invention.

[0059] According to the technical solution of the present invention, C 4 The content of C-hydrocarbon is not particularly limited, but in order to make the technical effect of the present invention more excellent, the C-hydrocarbon in the raw material 4 The content of - hydrocarbon is generally 0-10wt% (preferably 2-5wt%), based on the total weight of the raw material hydrocarbon as 100wt%. The inventors of the present invention have found that C 4 -Hydrocarbon and C5 -C 6 When hydrocarbon mixture is used as feedstock in the hydroconversion process, the feedstock needs to be pressurized before entering the feed pump in order to make C 4 - hydrocarbons are in liquid state, which also increases the difficulty of operation. In addition, the inventors of the present invention have found that as the carbon number of hydrocarbon molecules decreases, the difficulty of the conversion reaction gradually increases. 5 -C 6 Under the reaction conditions of isoalkanes, C 4 The difficulty of hydrocarbon conversion is relatively high (for example, the conversion rate is generally less than 20%), so C 4 Too high a hydrocarbon content will significantly inhibit the conversion activity of the raw hydrocarbon of the present invention, which is disadvantageous to the present invention.

[0060] According to the technical solution of the present invention, there is no particular restriction on the content of cyclic hydrocarbons in the raw material hydrocarbons, but in order to make the technical effect of the present invention more excellent, the content of cyclic hydrocarbons in the raw material hydrocarbons is generally 1-10wt% (preferably 2-5wt%), based on the total weight of the raw material hydrocarbons as 100wt%. The inventors of the present invention have found that, affected by the reaction conditions and the pore structure of the molecular sieve, cycloalkanes with complex branched structures and aromatic hydrocarbons with arbitrary structures are difficult to be converted in the conversion process of the present invention. After passing through the reaction system, the molecular structure of these cyclic hydrocarbons does not change and they directly enter the ethylene device as conversion products, affecting the ethylene and triene yields of the ethylene device, which is disadvantageous to the present invention.

[0061] According to the technical solution of the present invention, the method comprises the step of chemically converting the sulfur-containing feedstock hydrocarbon to obtain a sulfur-containing conversion product. Preferably, the chemical conversion is to convert at least a portion of the C 5 -C 6 The isoparaffin undergoes a conversion reaction in the presence of hydrogen. Here, at least a portion of the isoparaffin may be, for example, more than 30 wt%, more than 40 wt%, more than 50 wt%, more than 60 wt%, more than 70 wt%, more than 80 wt% or more than 90 wt% of the total amount. 5 -C 6 The conversion rate of isoparaffin is not particularly limited, therefore, C 5 -C 6 The isoparaffins can be converted once to achieve the conversion rate (single-pass conversion rate), or they can be recycled multiple times (for example, unreacted C 5 -C 6 This conversion rate is achieved after the conversion reaction is carried out after separation of the isoparaffins from the conversion products.

[0062] According to the technical solution of the present invention, the conversion reaction can be a hydrogenation normalization reaction to obtain C 4 -C6 The conversion product with normal alkanes as the main product can also be obtained by hydrocracking reaction with C 2 -C 3 The inventors of the present invention have found through research that C 5 and C 6 There are mainly two reaction pathways for isoparaffins in the conversion reaction process of the present invention, one is that isoparaffins are directly converted to generate normal paraffins with the same carbon number, i.e., normalization reaction, and the other is that isoparaffins are directly cracked to generate low-carbon paraffins, i.e., cracking reaction. Both of these reaction pathways need to occur on a catalyst with a shape-selective catalytic function, and the acidity of the molecular sieve will also affect the reaction process. For molecular sieves with a higher content of strong acid centers, cracking reactions are more likely to occur, while for molecular sieves with a higher content of medium-strong acid centers, normalization reactions are more likely to occur. The normalization reaction is affected by the content of isoparaffins in the raw material. The higher the content of isoparaffins in the raw material, the more the normalization reaction tends to proceed in the positive reaction direction. As the content of normal paraffins generated by the conversion increases, the occurrence of the normalization reaction will be suppressed. At this time, we need to increase the cracking reaction to further increase the yield of normal paraffins in the conversion product.

[0063] According to the technical solution of the present invention, the reaction conditions of the conversion reaction include: reaction pressure of 0.5-10.0MPaG (preferably 2.0-8.0MPaG or 2.0-5.0MPaG), reaction temperature of 250-500°C (preferably 350-450°C), liquid hourly volume space velocity of 0.1-15.0h -1 (Preferably 0.5-5.0h -1 ), the hydrogen to oil volume ratio is 10:1-2500:1 (preferably 100:1-2000:1 or 100:1-1000:1). The inventors of the present invention have found that the raw material hydrocarbon conversion reaction (such as C 4 Compared with the conversion reaction of raw hydrocarbons, the reaction conditions of the conversion reaction of the present invention are milder, especially the reaction temperature is lower, for example, generally 10-50°C lower. The inventors of the present invention also found that at this lower reaction temperature, C 5 -C 6 Isoalkanes still show high conversion rates, such as C 5 -C 6 Under the reaction conditions of the present invention, isoparaffins can exhibit a single-pass conversion rate of 30 wt % or more, 40 wt % or more, 50 wt % or more, 60 wt % or more, 70 wt % or more, 80 wt % or more, or 90 wt % or more. 4 Due to its molecular structure, its conversion is difficult. For the conversion process to proceed, dehydrogenation reaction must occur first, and C 4 The difficulty of dehydrogenation of hydrocarbons is much higher than that of C5 -C 6 Isoalkanes, which also cause 4 The conversion of hydrocarbons requires more stringent reaction conditions (such as a reaction temperature 20-30°C higher). 7+ The conversion of components is affected by the reaction conditions and the pore structure of the molecular sieve. Cycloalkanes with complex branched structures and aromatic hydrocarbons with arbitrary structures are difficult to convert in the conversion process of the present invention. After passing through the reaction system, the molecular structure of these cyclic hydrocarbons does not change and they directly enter the ethylene unit as conversion products, affecting the ethylene and triene yields of the ethylene unit.

[0064] According to the technical solution of the invention of this application, the conversion reaction is carried out in the presence of a catalyst, and the catalyst comprises a molecular sieve and an active metal component.

[0065] According to the technical solution of the present invention, the molecular sieve is a molecular sieve with shape-selective catalytic performance, preferably selected from one or more of mordenite, ZSM molecular sieve, SAPO molecular sieve and EU-1 molecular sieve, more preferably selected from one or more of mordenite and ZSM molecular sieve, particularly preferably selected from one or more of mordenite, ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, Beta molecular sieve and ZSM-38 molecular sieve, especially selected from one or more of mordenite and ZSM-5 molecular sieve. Here, based on the weight of the catalyst, the content of the molecular sieve is 30-80wt% (preferably 40-70wt%). The inventors of the present invention have found that the acid strength of the molecular sieve directly affects the reaction characteristics of isoparaffins. The molecular sieve has more strong acid centers and is more prone to cracking reactions, such as ZSM-5 molecular sieves; while the medium-strong acid centers are more, and it is easier to undergo normalization reactions, such as mordenite. Therefore, according to the present invention, different reaction pathways can be achieved by selecting the acid strength of the molecular sieve.

[0066] According to the technical solution of the present invention, the hydrogenation component is selected from at least one of the metals of Group VIB and Group VIII, the metal of Group VIB is preferably molybdenum and / or tungsten, and the metal of Group VIII is preferably cobalt and / or nickel. Here, based on the weight of the catalyst, the content of the Group VIB metal (in terms of oxide) is 5.0-30.0wt% (10.0-20.0wt%), and the content of the Group VIII non-noble metal (in terms of oxide) is 0.5-15.0wt% (preferably 3.0-10.0wt%).

[0067] According to the technical solution of the present invention, the catalyst further comprises a binder. The type of the binder can be a conventional choice in the art, including but not limited to aluminum oxide and silicon oxide, wherein aluminum oxide is preferred. Here, based on the weight of the catalyst, the content of the binder is 5-65wt% (preferably 10-35wt%).

[0068] According to the technical solution of the present invention, the specific surface area of ​​the catalyst is 200-400m 2 / g, and the pore volume is 0.25-0.45mL / g.

[0069] According to the technical solution of the invention of this application, the preparation method of the catalyst can be prepared according to conventional methods in the art. The preparation method includes the preparation of the carrier and the loading of the active metal component, wherein the preparation process of the carrier is as follows: the molecular sieve and the binder are mechanically mixed, molded, and then dried and calcined to prepare a catalyst carrier. Conventional conditions can be used for drying and calcining the carrier. The drying conditions are: drying at 100°C-150°C for 1-12 hours. The calcination conditions are: calcining at 450°C-550°C for 2.5-6.0 hours.

[0070] According to the technical solution of the invention of the present application, in the preparation method of the 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 saturated impregnation method, an excessive impregnation method or a complex impregnation method, that is, the catalyst carrier is impregnated with a solution containing the required active metal component, and then dried and calcined to obtain the first catalyst. The drying conditions are: drying at 100°C-150°C for 1-12 hours. The calcination conditions are: calcining at 450°C-550°C for 2.5-6.0 hours.

[0071] According to the present invention, the conversion product comprises C 2 -C 6 n-alkanes, and the conversion product contains sulfur. Preferably, the sulfur contained in the sulfur-containing feed hydrocarbon is substantially completely retained in the conversion product. In order to make the technical effect of the present invention more excellent, the C 7 + hydrocarbon content is not higher than 5wt% (preferably not higher than 1wt%), C 5 -C 6 The content of isoparaffin is 0-50wt% (preferably 10-40wt%), C 2 -C 6 The content of normal alkanes is 40-90wt% (preferably 50-80wt%), the content of cyclic hydrocarbons is not higher than 3wt% (preferably not higher than 1wt%), and the sulfur content is 50-1000mg / kg (preferably 100-200mg / kg), based on the total weight of the conversion product being 100wt%.

[0072] According to the technical solution of the present invention, the method further comprises the following steps: separating the conversion product to obtain C 2 -C 6 A separation stream mainly composed of normal alkanes (e.g., more than 80 wt%, more than 90 wt%, or more than 95 wt% of the total amount) is obtained. 5 -C 6 Isoalkanes. The unreacted C 5 -C 6 Isoparaffins can be used as recycled materials to continue the conversion reaction with the raw material hydrocarbons, thereby converting a higher proportion of C 5 -C 6 Conversion of isoalkanes to C 2 -C 6 Normal alkanes.

[0073] According to the technical solution of the invention of this application, the weight ratio of the separation stream to the raw hydrocarbon is 0.4-0.9:1 (preferably 0.5-0.8:1).

[0074] According to the technical solution of the present invention, the method further comprises the following steps: separating the conversion product to obtain 4 -C 6 A normal stream mainly composed of normal alkanes (e.g., more than 80 wt%, more than 90 wt%, or more than 95 wt% of the total amount) and / or a stream mainly composed of C 2 -C 3 A low-carbon stream mainly composed of hydrocarbons (e.g., accounting for more than 90 wt% or more than 95 wt% of the total). According to the specific situation of the conversion rate, unreacted C 5 -C 6 Isoalkanes. The unreacted C 5 -C 6 Isoparaffins can be used as recycled materials to continue the conversion reaction with the raw material hydrocarbons, thereby converting a higher proportion of C 5 -C 6 Conversion of isoalkanes to C 2 -C 6 Normal alkanes.

[0075] According to the technical solution of the invention of the present application, the conversion product, the separation stream, the normal stream or the low-carbon stream shows high chemical activity compared with the raw hydrocarbon, and can therefore be advantageously used in chemical treatments such as steam cracking, alkane degassing, hydrocracking, etc. to obtain high value-added chemicals, preferably used in steam cracking to produce ethylene.

[0076] According to the technical solution of the present invention, the conversion product, the separation stream, the normal stream or the low-carbon stream are steam cracked to obtain a cracking product containing ethylene. According to the present invention, the conversion product, the separation stream, the normal stream or the low-carbon stream is an ideal ethylene cracking feedstock, and the ethylene yield when using these streams is generally above 30wt%, thereby finding a high-value utilization method for the low-value-added raw material hydrocarbons in the prior art.

[0077] According to the technical solution of the present invention, the operating conditions of the steam cracking include: reaction temperature 750-900°C, reaction pressure 0.1-0.5MPaG, water-oil mass ratio 0.2-0.6, and sulfur injection amount to control the sulfur content in the raw material to be 100-200mg / kg. According to the present invention, since the conversion product, the separation stream, the normal stream or the low-carbon stream substantially retains the sulfur contained in the sulfur-containing raw hydrocarbon, the sulfur injection demand of the steam cracking can be reduced by at least 50%. In the most preferred case, the steam cracking can be completely free of additional sulfur injection, and only the sulfur contained in the conversion product, the separation stream, the normal stream or the low-carbon stream can be used to meet the steam cracking demand.

[0078] According to the technical solution of the invention of this application, it also relates to a sulfur-containing feedstock hydrocarbon conversion system, which includes a feedstock hydrocarbon supply unit, a feedstock hydrocarbon conversion unit and a steam cracking unit. According to the present invention, the system is specially set up to implement the method described in the foregoing text of this specification, so except for the contents clearly defined in this paragraph, any other contents or matters not clearly defined can directly refer to the contents or matters described in the foregoing text of this specification for the method, and there is no special limitation.

[0079] The present invention is further described below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

[0080] according to Figure 1 The sulfur-containing raw hydrocarbon 1 is mixed with hydrogen 2 and enters the hydroconversion reaction zone 3. The effluent 4 of the hydroconversion reaction zone enters the high-pressure separator 5. The separated gaseous stream hydrogen-rich gas 6 is recycled, and the liquid stream is used as an ethylene feedstock.

[0081] according to Figure 2 The sulfur-containing raw hydrocarbon 1 is mixed with hydrogen 2 and enters the hydroconversion reaction zone 3. The effluent 4 of the hydroconversion reaction zone enters the high-pressure separator 5. The separated gaseous stream hydrogen-rich gas 6 is recycled. The liquid stream 7 enters the distillation tower for separation to obtain a gaseous product 9 as an ethylene feedstock. The liquid product 10 is circulated to the inlet of the hydroconversion reaction zone 3.

[0082] Example

[0083] The present invention is further described in detail below using examples and comparative examples, but the present invention is not limited to these examples.

[0084] In the following examples and comparative examples, the calculation method of ethylene yield is the mass percentage of ethylene output to the feed amount of ethylene unit, and the ton of oil processing benefit refers to the income obtained from processing 1 ton of raw materials, and the calculation method is (ethylene product price - raw material and hydrogen price - processing energy consumption) / processing amount. The benchmark of ton of oil processing benefit is that the raw materials are directly used as ethylene raw materials without hydrogenation conversion.

[0085] In the following examples and comparative examples, each hydroconversion catalyst is represented by Cat-A plus a number, such as Cat-A1, Cat-A2, Cat-A3, etc. The hydroconversion catalyst is prepared by a conventional active metal saturation impregnation method, and the physicochemical properties of the obtained catalyst are shown in Table 1.

[0086] The preparation method of Cat-A1 to Cat-A3 catalysts is:

[0087] (1) Select SiO 2 / Al 2 O 3 Mordenite with a molar ratio of 15 was mechanically mixed with a binder, molded, dried at 120° C. for 10 hours, and calcined at 500° C. for 4 hours to prepare a catalyst carrier.

[0088] (2) The catalyst carrier obtained in step (1) is impregnated with the active component, dried at 120°C for 10 hours, and calcined at 500°C for 4 hours to prepare a hydrogenation conversion catalyst.

[0089] The preparation method of Cat-A4 to Cat-A6 catalysts is:

[0090] (1) Select SiO 2 / Al 2 O 3 ZSM-5 with a molar ratio of 10 was mechanically mixed with a binder, molded, dried at 120° C. for 10 hours, and calcined at 500° C. for 4 hours to prepare a catalyst carrier.

[0091] (2) The catalyst carrier obtained in step (1) is impregnated with the active component, dried at 120°C for 10 hours, and calcined at 500°C for 4 hours to prepare a hydrogenation conversion catalyst.

[0092] The properties of the raw materials are shown in Table 2. Among them, the raw material 5 needs to be obtained by adsorption separation or distillation of an isoparaffin-containing raw material.

[0093] Table 1

[0094]

[0095] Table 2

[0096]

[0097] Example 1

[0098] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0099] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A1;

[0100] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0101] In this case, C accounts for about 47 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.34:1.

[0102] Example 2

[0103] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0104] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A2;

[0105] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0106] In this example, C accounts for about 38 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.54:1.

[0107] Example 3

[0108] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0109] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A3;

[0110] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0111] In this example, C accounts for about 31 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.63:1.

[0112] Example 4

[0113] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0114] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A4;

[0115] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0116] In this example, C accounts for about 59 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.18:1.

[0117] Example 5

[0118] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0119] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A5;

[0120] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0121] In this example, C accounts for about 53 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.26:1.

[0122] Example 6

[0123] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0124] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A6;

[0125] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0126] In this example, C accounts for about 46 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.35:1.

[0127] Example 7

[0128] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 2 Process, including:

[0129] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A4;

[0130] (2) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone in step (1) is carried out into hydrogen-rich gas and liquid phase flow, the hydrogen-rich gas is recycled, and the liquid phase flow is separated to obtain C 2 and C 3 As ethylene feedstock, the remaining stream (called C 4 -C 6 The process conditions and conversion results in this example are shown in Table 3.

[0131] In this case, C accounts for about 78 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 3 Normal alkanes. C 4 -C 6 The weight ratio of the circulating stream to the raw material 1 is 0.1:1.

[0132] Example 8

[0133] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 2Process, including:

[0134] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A5;

[0135] (2) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone in step (1) is carried out into hydrogen-rich gas and liquid phase flow, the hydrogen-rich gas is recycled, and the liquid phase flow is separated to obtain C 2 and C 3 As a raw material for ethylene, C 4 -C 6 Cyclic cracking. The process conditions and conversion results in this example are shown in Table 3.

[0136] In this case, C accounts for about 78 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 3 Normal alkanes. C 4 -C 6 The weight ratio of the circulating stream to the feedstock 1 is 0.2:1.

[0137] Example 9

[0138] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 2 Process, including:

[0139] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A5;

[0140] (2) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone in step (1) is carried out into hydrogen-rich gas and liquid phase flow, the hydrogen-rich gas is recycled, and the liquid phase flow is separated to obtain C 2 and C 3 As a raw material for ethylene, C 4 -C 6 Cyclic cracking. The process conditions and conversion results in this example are shown in Table 3.

[0141] In this case, C accounts for about 78 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 3 Normal alkanes. C 4 -C 6 The weight ratio of the circulating stream to the feedstock 1 is 0.3:1.

[0142] Example 10

[0143] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0144] (1) Raw material 2 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A1;

[0145] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0146] In this example, C accounts for about 39 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.55:1.

[0147] Embodiment 11

[0148] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0149] (1) The raw material 3 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A4;

[0150] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0151] In this example, C accounts for about 36 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.51:1.

[0152] Example 12

[0153] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0154] (1) Raw material 1 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with hydroconversion catalyst Cat-A1;

[0155] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0156] In this example, C accounts for about 28 wt% of the total5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.68:1.

[0157] Embodiment 13

[0158] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0159] (1) The raw material 7 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A1;

[0160] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0161] In this case, C accounts for about 47 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.34:1.

[0162] Embodiment 14

[0163] The conversion method of sulfur-containing feed hydrocarbons adopts the following method: Figure 1 Process, including:

[0164] (1) The raw material 8 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A1;

[0165] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0166] In this case, C accounts for about 47 wt% of the total 5 -C 6 Isoalkanes are converted to C 2 -C 6 Normal alkanes. The weight ratio of the liquid phase flow to the feedstock 1 is 0.34:1.

[0167] Comparative Example 1

[0168] The conversion method of the raw hydrocarbon is as follows: Figure 1 Process, including:

[0169] (1) The raw material 4 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A1;

[0170] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0171] Comparative Example 2

[0172] The conversion method of the raw hydrocarbon is as follows: Figure 1 Process, including:

[0173] (1) The raw material 4 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A4;

[0174] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0175] Comparative Example 3

[0176] The conversion method of the raw hydrocarbon is as follows: Figure 1 Process, including:

[0177] (1) The raw material 5 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A1;

[0178] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0179] Comparative Example 4

[0180] The conversion method of the raw hydrocarbon is as follows: Figure 1 Process, including:

[0181] (1) The raw material 5 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A4;

[0182] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0183] Comparative Example 5

[0184] The conversion method of the raw hydrocarbon is as follows: Figure 1Process, including:

[0185] (1) The raw material 6 is mixed with hydrogen and sequentially enters the hydroconversion reaction zone; the hydroconversion reaction zone is loaded with the hydroconversion catalyst Cat-A1;

[0186] (2) Step (1) The gas-liquid separation of the reaction effluent from the hydroconversion reaction zone is into hydrogen-rich gas and liquid phase stream, the hydrogen-rich gas is recycled, and the liquid phase stream is directly used as ethylene feedstock. The process conditions and conversion results in this example are shown in Table 3.

[0187] Table 3 Transformation results

[0188] serial number Example 1 Example 2 Example 3 Hydrogenation conversion raw material Raw material 1 Raw material 1 Raw material 1 catalyst Cat-A1 Cat-A2 Cat-A3 Reaction temperature / ℃ 415 395 385 Reaction pressure / MPa 4 4 4 Hydrogen to oil volume ratio 800 600 700 <![CDATA[Space velocity per hour -1 > 1 0.6 1 <![CDATA[Product C 2 -C 6 Normal paraffin content, wt%]]> 63 54 47 Product sulfur content, mg / kg 100 150 200 Steam cracking to produce ethylene Sulfur supplementation amount of cracking raw materials, mg / kg 50 0 0 Reaction temperature / ℃ 880 880 880 Reaction pressure / MPa 0.3 0.3 0.3 Water-oil mass ratio 0.4 0.4 0.4 Ethylene yield, wt% 36.9 33.2 31.6 Propylene yield, wt% 15.7 17.4 17.8 Butadiene yield, wt% 3.5 3.8 3.8 Processing benefit per ton of oil, Yuan / ton Baseline+160 Baseline+180 Baseline +140 serial number Example 4 Example 5 Example 6 Hydrogenation conversion raw material Raw material 1 Raw material 1 Raw material 1 catalyst Cat-A4 Cat-A5 Cat-A6 Reaction temperature / ℃ 405 410 400 Reaction pressure / MPa 4 4 4 Hydrogen to oil volume ratio 600 400 600 <![CDATA[Space velocity per hour -1 > 0.6 0.6 1 <![CDATA[Product C 2 -C 6 Normal paraffin content, wt%]]> 75 69 62 Product sulfur content, mg / kg 120 140 180 Steam cracking to produce ethylene Sulfur supplementation amount of cracking raw materials, mg / kg 30 10 0 Reaction temperature / ℃ 880 880 880 Reaction pressure / MPa 0.3 0.3 0.3 Water-oil mass ratio 0.4 0.4 0.4 Ethylene yield, wt% 39.3 38.4 36.6 Propylene yield, wt% 13.9 14.5 15.7 Butadiene yield, wt% 3.5 3.6 3.5 Processing benefit per ton of oil, Yuan / ton Baseline +150 Baseline +170 Baseline+160

[0189] Table 3 Conversion results

[0190] serial number Example 7 Example 8 Example 9 Hydrogenation conversion raw material Raw material 1 Raw material 1 Raw material 1 catalyst Cat-A4 Cat-A5 Cat-A6 Reaction temperature / ℃ 405 400 393 Reaction pressure / MPa 4 4 4 Hydrogen to oil volume ratio 400 400 400 <![CDATA[Space velocity per hour -1 > 0.8 0.8 0.8 <![CDATA[Product C 2 -C 6 Normal paraffin content, wt%]]> 89 90 91 Product sulfur content, mg / kg 110 160 190 Steam cracking to produce ethylene Sulfur supplementation amount of cracking raw materials, mg / kg 40 0 0 Reaction temperature / ℃ 880 880 880 Reaction pressure / MPa 0.3 0.3 0.3 Water-oil mass ratio 0.4 0.4 0.4 Ethylene yield, wt% 45.3 45.8 46.4 Propylene yield, wt% 10.5 10.2 10 Butadiene yield, wt% 4.1 4.1 4 Processing benefit per ton of oil, Yuan / ton Baseline+80 Baseline+60 Baseline+160 serial number Example 10 Embodiment 11 Example 12 Hydrogenation conversion raw material Raw material 2 Raw material 3 Raw material 1 catalyst Cat-A1 Cat-A4 Cat-A1 Reaction temperature / ℃ 400 400 380 Reaction pressure / MPa 4 4 5 Hydrogen to oil volume ratio 400 400 400 Volume space velocity / h-1 1 0.8 0.6 <![CDATA[Product C 2 -C 6 Normal paraffin content, wt%]]> 55 52 44 Product sulfur content, mg / kg 50 300 150 Steam cracking to produce ethylene Sulfur supplementation amount of cracking raw materials, mg / kg 100 0 0 Reaction temperature / ℃ 880 880 880 Reaction pressure / MPa 0.3 0.3 0.3 Water-oil mass ratio 0.4 0.4 0.4 Ethylene yield, wt% 33.9 32.1 31.3 Propylene yield, wt% 17.3 17.5 18.1 Butadiene yield, wt% 3.7 3.9 3.9 Processing benefit per ton of oil, Yuan / ton Baseline+60 Baseline+50 Baseline+50

[0191] Table 3 Conversion results

[0192] serial number Embodiment 13 Embodiment 14 Hydrogenation conversion raw material Raw material 1 Raw material 1 catalyst Cat-A1 Cat-A1 Reaction temperature / ℃ 415 415 Reaction pressure / MPa 4 4 Hydrogen to oil volume ratio 800 800 <![CDATA[Space velocity per hour -1 > 1 1 <![CDATA[Product C 2 -C 6 Normal paraffin content, wt%]]> 62 63 Product sulfur content, mg / kg 40 800 Steam cracking to produce ethylene Sulfur supplementation amount of cracking raw materials, mg / kg 110 0 Reaction temperature / ℃ 880 880 Reaction pressure / MPa 0.3 0.3 Water-oil mass ratio 0.4 0.4 Ethylene yield, wt% 36.5 36.1 Propylene yield, wt% 15.7 15.8 Butadiene yield, wt% 3.5 3.5 Processing benefit per ton of oil, Yuan / ton Baseline +100 Baseline +90

[0193] Table 3 Conversion results

[0194]

[0195]

[0196] By comparison, it can be seen that the method of the present invention can effectively convert the sulfide in the raw material into hydrogen sulfide and selectively retain it in the conversion product. When the conversion product is used as an ethylene raw material, the amount of sulfur injection can be reduced or even eliminated, thereby realizing high-value utilization of worthless components.

Claims

1. A method for converting a sulfur-containing hydrocarbon feedstock, comprising the following steps: 1) providing a sulfur-containing feedstock hydrocarbon, wherein the sulfur content of the feedstock hydrocarbon is 50-5000 mg / kg (preferably 200-1000 mg / kg), relative to the total weight of the feedstock hydrocarbon, 2) chemically converting the sulfur-containing feed hydrocarbon to obtain a sulfur-containing conversion product, and 3) Steam cracking the sulfur-containing conversion product to obtain a cracking product containing ethylene.

2. The conversion method according to claim 1, wherein the sulfur-containing feedstock hydrocarbon contains C5-6 isoalkanes, and the chemical conversion is to cause at least a portion (for example, more than 30wt%, more than 40wt%, more than 50wt%, more than 60wt%, more than 70wt%, more than 80wt% or more than 90wt% of the total amount) of the C5-6 isoalkanes to undergo a conversion reaction in the presence of hydrogen, and the conversion product contains C2-6 normal alkanes.

3. The conversion method according to claim 1, wherein the initial distillation point of the sulfur-containing feedstock hydrocarbon is 10-30°C (preferably 15-25°C) and the final distillation point is 50-100°C (preferably 55-70°C).

4. The conversion method according to claim 1, wherein the content of C7+ hydrocarbons in the sulfur-containing feed hydrocarbon is 0-10wt% (preferably 0.5-5wt%), the content of C5-C6 isoparaffins is 50wt% or more (preferably 60-90wt%, more preferably 70-80wt%), the content of C5-C6 normal paraffins is 10-30wt% (preferably 15-25wt%), the content of C4- hydrocarbons is 0-10wt% (preferably 2-5wt%), the content of cyclic hydrocarbons is 1-10wt% (preferably 2-5wt%), the sulfur content is 0.5-1000mg / kg, and the content of C4- hydrocarbons is 0-10wt% (preferably 2-5wt%). The total weight of the raw hydrocarbon is 100wt%, and / or the content of C7+ hydrocarbons in the conversion product is not higher than 5wt% (preferably not higher than 1wt%), the content of C5-C6 isoparaffins is 0-50wt% (preferably 10-40wt%), the content of C2-C6 normal paraffins is 40-90wt% (preferably 50-80wt%), the content of cyclic hydrocarbons is not higher than 3wt% (preferably not higher than 1wt%), and the sulfur content is 50-1000mg / kg (preferably 100-200mg / kg), based on the total weight of the conversion product being 100wt%.

5. The conversion method according to claim 1, wherein the conversion process needs to be carried out in the presence of a catalyst, and the catalyst comprises a molecular sieve and an active metal component.

6. The conversion method according to claim 5, wherein the molecular sieve is a molecular sieve having shape-selective catalytic performance, preferably selected from one or more of mordenite, ZSM molecular sieve, SAPO molecular sieve and EU-1 molecular sieve, more preferably selected from one or more of mordenite and ZSM molecular sieve, particularly preferably selected from one or more of mordenite, ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, Beta molecular sieve and ZSM-38 molecular sieve, in particular selected from one or more of mordenite and ZSM-5 molecular sieve.

7. The conversion method according to claim 5, wherein the catalyst further comprises a binder (preferably alumina), and the content of the binder is 5-65wt% (preferably 10-35wt%) based on the weight of the catalyst.

8. The conversion method according to claim 5, wherein the hydrogenation component is selected from at least one of metals of Group VIB and Group VIII, the metal of Group VIB is preferably molybdenum and / or tungsten, and the metal of Group VIII is preferably cobalt and / or nickel.

9. The conversion method according to claim 8, wherein the content of the VIB group metal (calculated as oxide) is 5.0-30.0 wt% (preferably 10-20 wt%), and the content of the VIII group non-noble metal (calculated as oxide) is 0.5-15.0 wt% (preferably 3-10 wt%), based on the weight of the catalyst.

10. The conversion method according to claim 5, wherein the content of the molecular sieve is 30-80wt% (preferably 40-70wt%) based on the weight of the catalyst.

11. The conversion method of claim 1, wherein the reaction conditions of the conversion reaction include: The reaction pressure is 0.5-10.0MPaG (preferably 2.0-8.0MPaG or 2.0-5.0MPaG), the reaction temperature is 250-500℃ (preferably 350-450℃), and the liquid hourly volume space velocity is 0.1-15.0h -1 (Preferably 0.5-5.0h -1 ), the volume ratio of hydrogen to oil is 10:1-2500:1 (preferably 100:1-2000:1 or 100:1-1000:1).

12. The method of claim 1, further comprising the steps of: Optionally separating the conversion product to obtain a separated stream mainly composed of C2-C6 normal alkanes (e.g., accounting for more than 80wt%, more than 90wt% or more than 95wt% of the total amount), or separating the conversion product to obtain a normal stream mainly composed of C4-C6 normal alkanes (e.g., accounting for more than 80wt%, more than 90wt% or more than 95wt% of the total amount) and / or a low-carbon stream mainly composed of C2-C3 hydrocarbons (e.g., accounting for more than 90wt% or more than 95wt% of the total amount), and The conversion product, the separation stream, the normal stream or the low-carbon stream is steam cracked to obtain a cracking product comprising ethylene.

13. The conversion method according to claim 12, wherein the weight ratio of the separated stream to the feed hydrocarbon is 0.4-0.9:1 (preferably 0.5-0.8:1).

14. The conversion method of claim 12, wherein the operating conditions of the steam cracking include: The reaction temperature is 750-900°C, the reaction pressure is 0.1-0.5MPaG, the water-oil mass ratio is 0.2-0.6, and the sulfur content of the system is 100-200mg / kg.

15. A system for converting sulfur-containing hydrocarbon feedstock, comprising the following units: 1) A feedstock hydrocarbon supply unit, which is configured to provide a sulfur-containing feedstock hydrocarbon, wherein the sulfur content of the feedstock hydrocarbon is 50-5000 mg / kg (preferably 200-1000 mg / kg), relative to the total weight of the feedstock hydrocarbon, 2) a feedstock hydrocarbon conversion unit configured to chemically convert the sulfur-containing feedstock hydrocarbon to obtain a sulfur-containing conversion product, and 3) A steam cracking unit configured to steam crack the sulfur-containing conversion product to obtain a cracking product comprising ethylene.

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