A method and system for the production of low sulfur fuel oil components and low carbon olefins
By fractionating feedstock oil into light and heavy components and then subjecting it to catalytic cracking and hydrodesulfurization, the problems of resource waste and economic efficiency in the production of low-sulfur fuel oil and low-carbon olefins have been solved, and a method and system for the efficient production of low-sulfur fuel oil and low-carbon olefins has been realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2021-10-14
- Publication Date
- 2026-07-14
AI Technical Summary
Existing refineries face challenges in producing low-sulfur fuel oil and low-carbon olefins, including limited and high-priced low-sulfur crude oil resources, or issues with the economic benefits of feeding into vacuum residue catalytic cracking units. Furthermore, the production of saturated hydrocarbon resources in vacuum residue is subject to significant waste, impacting enterprise profitability.
The feedstock oil is fractionated into light and heavy components in the first fractionation tower. The heavy components are catalytically cracked in a catalytic cracking reactor under hydrogen-free conditions, separating catalytic wax oil fraction and low-carbon olefins. The light components and catalytic wax oil fraction are hydrodesulfurized, and the light gasoline fraction is recycled back to the reactor to optimize product distribution.
It improved the yield of low-sulfur fuel oil components and low-carbon olefins, reduced the energy consumption of the catalytic unit, optimized the hydrogen distribution of the products, and enhanced economic and social benefits.
Smart Images
Figure CN115975676B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of catalytic cracking, specifically to a method for catalytically cracking hydrocarbon feedstock into low-sulfur fuel oil components while simultaneously producing low-carbon olefins. Background Technology
[0002] According to the International Maritime Organization (IMO) Convention for the Prevention of Pollution from Ships, starting from January 1, 2020, ships worldwide must use marine fuel with a sulfur content not exceeding 0.5%.
[0003] There are two main existing low-sulfur fuel oil production schemes in refineries. One is to purchase low-sulfur crude oil and feed it into an atmospheric or vacuum distillation unit, directly using the resulting atmospheric or vacuum residue as a blending component for low-sulfur fuel oil. The other is to feed high-sulfur crude oil into an atmospheric or vacuum distillation unit, obtaining atmospheric or vacuum residue. However, due to excessive sulfur content in the residue, it cannot be used as a blending component for low-sulfur fuel oil. The resulting residue fraction must be sent to a residue hydrotreating unit to obtain hydrotreated heavy oil, which is then used as a blending component for low-sulfur fuel oil. For example, CN109722303A discloses a method for increasing the production of low-sulfur marine fuel oil blending components from high-sulfur heavy oil. These conventional low-sulfur fuel oil production routes either suffer from the problem of scarce and expensive low-sulfur crude oil resources or squeeze the feedstock of the residue catalytic cracking unit, thus affecting the refinery's economic efficiency. The saturated hydrocarbons in vacuum residue are excellent precursors for the production of low-carbon olefins such as propylene and isobutylene. Using them directly as fuel oil components instead of catalytic feedstock inevitably leads to resource waste and affects the enterprise's economic efficiency.
[0004] Currently, the demand for organic chemical intermediates such as propylene and isobutylene in my country is constantly increasing. By utilizing the core refining unit—catalytic cracking—the saturated hydrocarbons in the feedstock can be selectively converted into low-carbon olefins such as propylene and isobutylene at the molecular level. Polycyclic aromatic hydrocarbons are retained to the greatest extent in the fuel oil blending components, avoiding excessive condensation reactions that lead to coke, reducing coke generation in the catalytic unit, and lowering carbon dioxide emissions from the refinery. Summary of the Invention
[0005] This application provides a method for producing more low-sulfur fuel oil components and low-carbon olefins, comprising:
[0006] i) The feedstock oil is fed into the first fractionation tower, where it is fractionated to obtain light and heavy components of the feedstock oil;
[0007] ii) The heavy components of the feedstock are brought into contact with the catalytic cracking catalyst in a catalytic cracking reactor in the absence of hydrogen to carry out a catalytic cracking reaction, and the reaction products are obtained;
[0008] iii) Separate catalytic cracking wax oil fraction, low-carbon olefins and light gasoline fraction from the reaction product obtained in step ii), wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%.
[0009] iv) The light component of the feedstock oil from step i) and the catalytic cracking wax oil fraction from step iii) are subjected to hydrodesulfurization treatment to obtain a low-sulfur fuel oil component;
[0010] v) Return the light gasoline fraction to the catalytic cracking reactor.
[0011] In one embodiment, the fractionation temperature for obtaining the light and heavy components of the feedstock oil in step i) is 330–380°C, preferably 340–370°C, and most preferably 350–360°C.
[0012] In one embodiment, the final boiling point of the light gasoline fraction is not greater than 120°C, preferably not greater than 100°C, and most preferably not greater than 90°C.
[0013] And / or, the olefin content in the light gasoline fraction is not less than 50 vol%, more preferably not less than 60 vol%, and most preferably not less than 80 vol%.
[0014] In one embodiment, the initial boiling point of the catalytic cracking wax oil fraction is not less than 250°C, and the final boiling point is not greater than 520°C, preferably not greater than 500°C.
[0015] In one embodiment, the yield of the catalytic cracking wax oil fraction in the reaction products is not less than 15% by weight of the feedstock oil, preferably not less than 20%, and not more than 50%.
[0016] In one embodiment, the conditions for the hydrodesulfurization treatment include: a reaction pressure of 2.0-24.0 MPa, a reaction temperature of 200-500°C, and a hydrogen-to-oil volume ratio of 50-5000 Nm³. 3 / m 3 The liquid hourly space velocity is 0.1-30.0 h⁻¹. -1 ;
[0017] In one embodiment, the conditions for the hydrodesulfurization treatment include: a reaction pressure of 3.0-10.0 MPa; a reaction temperature of 250-380°C; and a hydrogen-to-oil volume ratio of 200-2000 Nm³. 3 / m 3 The liquid hourly space velocity is 0.2-10.0 h⁻¹. -1 .
[0018] In one embodiment, the reaction conditions for the catalytic cracking reaction include: a reaction temperature of 500-680°C and a weight hourly space velocity of 20-100 h⁻¹.-1 Alternatively, the reaction time may be 2-8 seconds, and the agent-to-oil weight ratio may be 5-12.
[0019] In one embodiment, the mass ratio of propylene to propane in the reaction product is not less than 4, preferably not less than 6, and most preferably not less than 8.
[0020] In one embodiment, the sulfur content in the low-sulfur fuel oil component is no more than 0.1%, preferably no more than 0.05%.
[0021] This application also provides a system for producing more low-sulfur fuel oil components and low-carbon olefins.
[0022] The first fractionation tower is used to fractionate the feed oil to obtain light components and heavy components of the feed oil.
[0023] A catalytic cracking reactor is used to carry out catalytic cracking reactions of heavy components of feedstock oil from the first fractionation tower within the catalytic cracking reactor to obtain reaction products;
[0024] A separation system is used to separate the reaction products into catalytic cracking wax oil fraction, low-carbon olefins, and light gasoline fraction, wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%; wherein the light gasoline fraction outlet pipeline of the separation system is connected to the catalytic cracking reactor of the catalytic cracking reactor, so that the light gasoline fraction is returned to the catalytic cracking reactor;
[0025] The hydrodesulfurization unit is used to perform hydrodesulfurization treatment on catalytic cracking wax oil fractions and light components of feedstock oil to obtain low-sulfur fuel oil components.
[0026] In one embodiment, the separation system includes:
[0027] The product fractionation tower is used to separate the reaction products into dry gas fraction, liquefied gas fraction, gasoline fraction, light circulating oil fraction, catalytic cracking wax oil fraction and oil slurry fraction.
[0028] A liquefied petroleum gas (LPG) fractionation tower is used to separate LPG fractions to obtain propylene and butene.
[0029] A gasoline fractionation tower is used to separate the gasoline fraction into a heavy gasoline fraction and a light gasoline fraction, wherein the outlet of the light gasoline fraction of the gasoline fractionation tower is connected to a feedstock inlet of the catalytic cracking reactor of the catalytic cracking unit, so that the light gasoline fraction is recycled back to the catalytic cracking reactor.
[0030] In one embodiment, the oil slurry fraction outlet of the product fractionation tower is connected to a feedstock inlet of the catalytic cracking reactor of the catalytic cracking unit, so that the oil slurry fraction is recycled back to the catalytic cracking reactor.
[0031] The method of this application can selectively convert alkanes and hydrocarbons with alkyl side chains in the heavy components of hydrocarbon-containing feedstocks to propylene and isobutylene to the greatest extent possible. Meanwhile, the light components in the hydrocarbon-containing feedstocks, after hydrodesulfurization, retain bicyclic and polycyclic aromatic hydrocarbons and cycloalkanes that are less prone to cracking to form low-carbon olefins, which can be used as blending components for fuel oil. Through this method, the yield and selectivity of propylene and isobutylene can be further improved while producing fuel oil components, reducing the energy consumption of the catalytic cracking unit and optimizing the hydrogen distribution of the products.
[0032] Specifically, the method of this application has at least one of the following technical effects compared with the prior art:
[0033] 1. While producing fuel oil components, further improving the selectivity and yield of low-carbon olefins such as propylene and isobutylene has certain economic and social benefits;
[0034] 2. By specifically selecting light components in the feedstock oil and excluding them from catalytic cracking, the energy consumption of the catalytic cracking unit can be reduced, while the yield of fuel oil components can be increased. Attached Figure Description
[0035] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings:
[0036] Figure 1 This is a flowchart illustrating the method and system of this application. Detailed Implementation
[0037] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.
[0038] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.
[0039] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.
[0040] This application provides a method for producing more low-sulfur fuel oil components and low-carbon olefins, comprising:
[0041] i) The feedstock oil is fed into the first fractionation tower, where it is fractionated to obtain light and heavy components of the feedstock oil;
[0042] ii) The heavy components of the feedstock are brought into contact with the catalytic cracking catalyst in a catalytic cracking reactor in the absence of hydrogen to carry out a catalytic cracking reaction, and the reaction products are obtained;
[0043] iii) Separate catalytic cracking wax oil fraction, low-carbon olefins and light gasoline fraction from the reaction product obtained in step ii), wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%.
[0044] iv) The light component of the feedstock oil from step i) and the catalytic cracking wax oil fraction from step iii) are subjected to hydrodesulfurization treatment to obtain a low-sulfur fuel oil component;
[0045] v) Return the light gasoline fraction to the catalytic cracking reactor.
[0046] At the same time, such as Figure 1 As shown, this application provides a system for producing more low-sulfur fuel oil components and low-carbon olefins.
[0047] The first fractionation tower 34 is used to fractionate the feed oil to obtain the light component 35 and the heavy component 36 of the feed oil.
[0048] The catalytic cracking reactor 100 is used to carry out catalytic cracking reaction of the heavy component 36 of the feed oil from the first fractionation tower 34 in the catalytic cracking reactor 2 of the catalytic cracking reactor 100 to obtain reaction products.
[0049] The separation system 200 is used to separate the reaction products into catalytic cracking wax oil fraction 23, low-carbon olefins 26 and 27, and light gasoline fraction 31, wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%. The light gasoline fraction outlet pipeline of the separation system 200 is connected to the catalytic cracking reactor 2 of the catalytic cracking reactor 100, allowing the light gasoline fraction to be returned to the catalytic cracking reactor 2.
[0050] The hydrodesulfurization unit 32 is used to perform hydrodesulfurization treatment on the catalytic cracking wax oil fraction 23 and the light component 35 of the feedstock oil to obtain low-sulfur fuel oil component 33.
[0051] The following combination Figure 1 The method and system of the present invention are described.
[0052] In one embodiment, the feedstock oil used in this invention is selected from petroleum hydrocarbons, other mineral oils, or mixtures thereof. The petroleum hydrocarbons are selected from vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, hydrotreated wax oil, hydrotreated residue, hydrotreated heavy oil, top-load oil, or any mixture thereof. The other mineral oils are selected from coal liquefaction oil, oil sands oil, shale oil, or any mixture thereof. In another embodiment, the feedstock oil may be selected from petroleum hydrocarbons, other mineral oils, or mixtures thereof. The petroleum hydrocarbons may be selected from vacuum gas oil (VGO), atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue (VR), atmospheric residue, hydrotreated wax oil, hydrotreated residue, hydrotreated heavy oil, top-load oil, or various mixtures thereof. The other mineral oils may be selected from coal liquefaction oil, oil sands oil, shale oil, or various mixtures thereof.
[0053] In the method of this invention, a first fractionation tower is used to cut the feedstock oil 3 into light feedstock components 35 and heavy feedstock components 36. The inventors of this invention unexpectedly discovered that cutting the feedstock oil 3 into different light and heavy components and subjecting the light and heavy components to different treatments can improve the yield of low-sulfur fuel oil components and the yield of low-carbon olefins such as propylene and butene.
[0054] In one embodiment, the cutting temperature points (fractionation points) of the light and heavy components of the feedstock are controlled between 330 and 380°C, preferably between 340 and 370°C, and most preferably between 350 and 360°C. The low-boiling-point components (components below the fractionation point) are the light components of the feedstock, and the high-boiling-point components (components above the fractionation point) are the heavy components. The high-boiling-point heavy components are fed into the catalytic cracking reactor 2 of the catalytic cracking reactor 100 for catalytic cracking reaction to obtain reaction products.
[0055] The catalytic cracking reactor 100 typically includes a catalytic cracking reactor 2 for carrying out the catalytic cracking reaction; a settling tank 7 for separating the catalyst; a stripper 10 for stripping the separated catalyst using stripping steam 11; and a regenerator 13, in which the catalyst to be recycled enters through a regenerating inclined tube 12 and is regenerated under the action of regeneration gas 13. The regenerated catalyst is then returned to the catalytic cracking reactor 2 through a regeneration inclined tube 16, and the regeneration flue gas 15 is discharged from the top. The structure of these devices and the connection methods between them can be in accordance with structures and methods known in the art, and will not be described in detail here.
[0056] In one embodiment, the catalytic cracking reactor 2 can be a fluidized bed reactor of various forms, such as a single fluidized bed reactor or a composite reactor obtained by combining multiple fluidized bed reactors in series or parallel. In some preferred embodiments, the fluidized bed reactor can be a constant-diameter riser reactor or a fluidized bed reactor of various variable diameter forms, such as the reactor disclosed in Chinese Patent CN1078094C.
[0057] like Figure 1 As shown, the catalytic cracking reactor 2 includes a first reaction zone 8 and a second reaction zone 9. Heavy feedstock components 36 enter the catalytic cracking reactor 2 from the lower part of the first reaction zone 8 under the action of steam 4. Meanwhile, the regenerated catalyst, entering from the regeneration inclined tube 16, enters the catalytic cracking reactor 2 under the action of the pre-lifting medium 1, thereby contacting the heavy feedstock components 36 and carrying out the catalytic cracking reaction. As will be described later, the light gasoline fraction 31 can also be recycled back to the catalytic cracking reactor 2 under the action of steam 6, and the slurry oil 24 can also be recycled back under the action of steam 5.
[0058] According to this application, various catalytic cracking catalysts known in the art can be used. In one embodiment, the catalytic cracking catalyst may comprise, by weight of the total catalyst, about 1-50 wt% zeolite, about 5-99 wt% inorganic oxides, and about 0-70 wt% clay. Preferably, the catalyst may comprise about 5-45 wt% zeolite, more preferably about 10-40 wt% zeolite, about 5-80 wt% inorganic oxides, and about 10-70 wt% clay.
[0059] In a preferred embodiment, the zeolite comprises, by total weight, about 51-100 wt%, preferably about 70-100 wt%, of mesoporous zeolite and about 0-49 wt%, preferably about 0-30 wt%, of macroporous zeolite. The mesoporous zeolite is preferably selected from ZSM series zeolites and ZRP zeolites; the macroporous zeolite is preferably one or more of Beta series zeolites and Y series zeolites.
[0060] In one embodiment, the reaction conditions of the catalytic cracking reaction are controlled such that the yield of the catalytic cracked wax oil fraction in the resulting reaction products is not less than about 15% by weight of the feedstock oil, preferably not less than about 20%, and not more than about 50%. In one embodiment, the reaction conditions of the catalytic cracking reaction include: a reaction temperature of 500-680°C and a weight hourly space velocity of 20-100 h⁻¹. -1 Alternatively, the reaction time may be 2-8 seconds, and the agent-to-oil weight ratio may be 5-12.
[0061] In one embodiment, the mass ratio of propylene to propane in the reaction product is not less than 4, preferably not less than 6, and most preferably not less than 8.
[0062] like Figure 1 As shown, the oil and gas 17 (reaction products) discharged from the settler 7 enters the separation system 200 via pipeline for separation to obtain the respective products. The separation system 200 includes a product fractionation tower 18, in which the oil and gas 17 (reaction products) is separated according to their respective boiling ranges into dry gas fraction 19, liquefied petroleum gas fraction 20, gasoline fraction 21, light cycle oil fraction 22, catalytic cracking wax oil fraction 23, and slurry oil fraction 24. In one embodiment, the initial boiling point of the catalytic cracking wax oil fraction is not less than 250°C, and the final boiling point is not greater than 520°C, preferably not greater than 500°C.
[0063] The separation system 200 includes a liquefied gas fractionation tower 25 for separating liquefied gas fraction 20 to obtain propylene 26 and butene 27, as well as other hydrocarbons 28.
[0064] The separation system 200 includes a gasoline fractionation tower 29 for separating the gasoline fraction 21 into a heavy gasoline fraction 30 and a light gasoline fraction 31. In one embodiment, the final boiling point of the light gasoline fraction is not greater than 120°C, preferably not greater than 100°C, and most preferably not greater than 90°C; and / or, the olefin content in the light gasoline fraction is not less than 50 v%, more preferably not less than 60 v%, and most preferably not less than 80 v%. In this application, the outlet of the light gasoline fraction 31 of the gasoline fractionation tower 29 is connected to a feedstock inlet of the catalytic cracking reactor 2 of the catalytic cracking reactor, so that the light gasoline fraction 31 is recycled back to the catalytic cracking reactor 2.
[0065] The system of this application includes a hydrodesulfurization unit 32, which is used to hydrodesulfurize the catalytic cracking wax oil fraction 23 and the light component 35 of the feedstock oil to obtain a low-sulfur fuel oil component 33.
[0066] In one embodiment, the catalyst used in the hydrodesulfurization treatment is a catalyst comprising a Group VIB metal and / or a Group VIII metal supported on an alumina and / or amorphous silica-alumina support. More preferably, the catalyst used in the hydrodesulfurization treatment comprises about 0-10 wt% additives, about 1-40 wt% of at least one Group VIII metal (based on metal oxides), about 1-50 wt% of at least one Group VIB metal (based on metal oxides), and the balance being a support selected from alumina and amorphous silica-alumina, wherein the additives comprise nonmetallic elements selected from fluorine, phosphorus, etc., metallic elements selected from titanium, platinum, etc., or combinations thereof. For example, the additives may be phosphorus-containing or fluorine-containing additives, such as ammonium fluoride. The Group VIB metal is preferably selected from molybdenum, tungsten, or combinations thereof; the Group VIII metal is preferably selected from nickel, cobalt, or combinations thereof.
[0067] In one embodiment, the conditions for the hydrodesulfurization treatment include: a reaction pressure of about 2.0-24.0 MPa, preferably about 3.0-10.0 MPa; a reaction temperature of about 200-500°C, preferably about 250-380°C; and a hydrogen-to-oil volume ratio of about 50-5000 Nm³. 3 / m 3 Preferably around 200-2000 Nm 3 / m 3 The liquid hourly space velocity is approximately 0.1–30.0 h⁻¹. -1 Preferably, it takes about 0.2-10.0 hours. -1 .
[0068] In one embodiment, the conditions for the hydrodesulfurization treatment include: a reaction pressure of approximately 2.0-24.0 MPa, a reaction temperature of approximately 200-500°C, and a hydrogen-to-oil volume ratio of approximately 50-5000 Nm. 3 / m 3 The liquid hourly space velocity is approximately 0.1–30.0 h⁻¹. -1 ;
[0069] Preferably, the conditions for the hydrodesulfurization treatment include: a reaction pressure of approximately 3.0-10.0 MPa; a reaction temperature of approximately 250-380°C; and a hydrogen-to-oil volume ratio of approximately 200-2000 Nm³. 3 / m 3 The liquid hourly space velocity is approximately 0.2-10.0 h⁻¹. -1 .
[0070] In one embodiment, the low-sulfur hydrotreated distillate oil obtained after hydrodesulfurization can be used as a fuel oil blending component, wherein the sulfur content is no more than about 0.1%, preferably no more than about 0.05%.
[0071] In this application, low carbon olefins refer to C2-C4 olefins, such as ethylene, propylene, butene (including isobutene), and particularly propylene and butene (including isobutene).
[0072] For a long time, those skilled in the art have believed that catalytic cracking has low requirements for feedstock. As long as the conventional properties of the feedstock, such as heavy metal content, residual carbon, and density, meet the feedstock requirements, the lower the initial boiling point and the lower the density, the higher the yield of target products such as low-carbon olefins. However, through creative thinking and repeated experiments, the inventors discovered that a lower initial boiling point is not necessarily better for heavy oil catalytic cracking feedstocks. When the initial boiling point is below a certain value, the selectivity and yield of high-value target products such as low-carbon olefins will decrease. Therefore, the method of this invention separates components that are not easily converted into low-carbon olefins and affect the high selectivity of other hydrocarbon molecules to low-carbon olefins during catalytic cracking before catalytic cracking. This can further improve the selectivity and yield of low-carbon olefins, as well as the yield of low-sulfur fuel oil components. Furthermore, since the light components of the feedstock do not enter the catalytic cracking unit, the energy consumption of the catalytic cracking unit is greatly reduced.
[0073] The present application will be further described below with reference to the embodiments, but this does not limit the present application.
[0074] The properties of the feedstock and catalyst used in the following examples and comparative examples are listed in Tables 1 and 2. The catalytic conversion catalysts used in the examples and comparative examples were TCC catalysts, produced by Qilu Catalyst Branch.
[0075] Example 1
[0076] according to Figure 1 The process shown was tested using hydrotreated heavy oil as feedstock. The feedstock was split into light and heavy components in the first fractionation tower at 350°C. The heavy components of the hydrotreated heavy oil were then tested in a variable-diameter fluidized bed reactor using a TCC catalyst as the catalytic conversion catalyst. Oil and gas were separated from the spent catalyst in a settling tank. The product oil and gas were separated according to their boiling range in the fractionation unit (oil-gas fractionation tower) and the absorption stabilization section, yielding liquefied petroleum gas (LPG), which was further separated into propylene, butene, etc., in a LPG fractionation tower, gasoline, light cycle oil, catalytic cracking wax oil (boiling range 250-500°C), and slurry oil. The gasoline was split in a gasoline fractionation tower to obtain fractions below 90°C, which were returned to the bottom of the riser. The obtained catalytic cracking wax oil, the light components of the hydrotreated heavy oil, and hydrogen entered the hydrodesulfurization reactor to contact with the hydrodesulfurization catalyst, yielding low-sulfur hydrotreated distillate oil. The reaction conditions and product distribution are listed in Table 3.
[0077] Comparative Example 1
[0078] according to Figure 1The process illustrated in the experiment was conducted using hydrotreated heavy oil as feedstock, which was directly fed into a variable-diameter fluidized bed reactor. A TCC catalyst was used as the catalytic conversion catalyst. Oil and gas were separated from the catalyst in a settling tank. The product oil and gas were separated according to their boiling range in a fractionation unit (oil-gas fractionation tower), yielding liquefied petroleum gas (LPG), which was further separated into propylene, butene, etc., in a LPG fractionation tower, gasoline, light cycle oil, catalytic cracking wax oil (boiling range 250-500℃), and slurry oil. The gasoline was further fractionated in a gasoline fractionation tower to obtain fractions below 90℃, which were returned to the bottom of the riser. The resulting catalytic cracking wax oil and hydrogen entered a hydrodesulfurization reactor under the same hydrotreating conditions as in the previous example. The resulting low-sulfur hydrotreated distillate oil can be used as a fuel oil blending component. The reaction conditions and product distribution are listed in Table 3.
[0079] Comparative Example 2
[0080] Comparative Example 2 is similar to Example 1, except that the gasoline fraction is not cut and recycled back to the riser reactor through a gasoline fractionation tower. The gasoline is directly discharged from the unit as a product. The product distribution is shown in Table 3.
[0081] As can be seen from the reaction results in Table 3, Comparative Example 1 only yielded 28.22 wt% low-sulfur hydrotreated distillate (low-sulfur marine fuel oil), 11.32 wt% propylene, and 9.60 wt% butene (4.40 wt% isobutene). Compared to Comparative Example 1, the Example, with a 0.3 percentage point decrease in coke yield, yielded 31.43 wt% low-sulfur hydrotreated distillate (low-sulfur marine fuel oil), 11.97 wt% propylene, and 11.04 wt% butene (4.97 wt% isobutene). Compared to Comparative Example 2, the Example showed a significant increase in the yield of propylene and butene while maintaining a comparable yield of low-sulfur hydrotreated distillate (low-sulfur marine fuel oil).
[0082] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0083] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.
[0084] Table 1. Properties of the feedstock oils used in Example 1 and Comparative Examples 1-2
[0085] Crude oil name Hydrogenated heavy oil <![CDATA[Density (20 °C), g / cm 3 > 916.7 Element / Weight % carbon 87.0 sulfur 0.40 nitrogen 0.09
[0086] Table 2. Properties of the catalytic conversion catalysts used in Example 1 and Comparative Examples 1-2
[0087] Catalyst grades TCC physical properties <![CDATA[Bulk density / (g·cm -3 )]]> 0.78 <![CDATA[Wear index / (%·h -1 )]]> 1.3 Sieving composition / weight% 0-40μm 16.2 0-80μm 58.8 0-105μm / 0-149μm 96.0
[0088] Table 3 Reaction conditions and product distribution of Example 1 and Comparative Example 1
[0089]
[0090] *In Examples 1, 1, and 2, the hydrogen consumption of the hydrogenation unit relative to the catalyst feedstock was 0.30%, 0.23%, and 0.27%, respectively.
Claims
1. A method for producing multiple low-sulfur fuel oil components and low-carbon olefins, characterized in that, The method includes: i) The feedstock oil is fed into the first fractionation tower, and fractionation is carried out to obtain light components and heavy components of the feedstock oil. The fractionation temperature for obtaining the light components and heavy components of the feedstock oil is 330~380℃. ii) The heavy components of the feedstock are brought into contact with the catalytic cracking catalyst in a catalytic cracking reactor in the absence of hydrogen to carry out a catalytic cracking reaction, and the reaction products are obtained; iii) Separate the catalytic cracking wax oil fraction, low-carbon olefins, and light gasoline fraction from the reaction products obtained in step ii), wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%. iv) The light components of the feedstock oil from step i) and the catalytic cracking wax oil fraction from step iii) are subjected to hydrodesulfurization treatment to obtain low-sulfur fuel oil components; v) Return the light gasoline fraction to the catalytic cracking reactor.
2. The method according to claim 1, characterized in that, Step i) The fractionation temperature for obtaining the light and heavy components of the feedstock oil is 340~370℃.
3. The method according to claim 2, characterized in that, Step i) The fractionation temperature for obtaining the light and heavy components of the feedstock oil is 350~360℃.
4. The method according to claim 1, characterized in that, The feedstock oil is selected from petroleum hydrocarbons, other mineral oils, or mixtures thereof, wherein the petroleum hydrocarbons are selected from vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, hydrotreated wax oil, hydrotreated residue, hydrotreated heavy oil, or any mixture thereof, and the other mineral oils are selected from coal liquefaction oil, oil sands oil, shale oil, or any mixture thereof.
5. The method according to claim 1, characterized in that, The final boiling point of the light gasoline fraction is not greater than 100°C.
6. The method according to claim 1, characterized in that, The final boiling point of the light gasoline fraction is not greater than 90°C.
7. The method according to claim 1, characterized in that, The olefin content in the light gasoline fraction is not less than 60%.
8. The method according to claim 1, characterized in that, The olefin content in the light gasoline fraction is not less than 80%.
9. The method according to any one of claims 1-8, characterized in that, The initial boiling point of the catalytic cracking wax oil fraction is not less than 250℃, and the final boiling point is not greater than 520℃.
10. The method according to claim 9, characterized in that, The final boiling point of the catalytic cracking wax oil fraction is not greater than 500℃.
11. The method according to any one of claims 1-8, characterized in that, In the reaction products, the yield of the catalytic cracking wax oil fraction is not less than 15% of the weight of the feedstock oil.
12. The method according to any one of claims 1-8, characterized in that, In the reaction products, the yield of the catalytic cracking wax oil fraction is not less than 20% and not more than 50% of the weight of the feedstock oil.
13. The method according to any one of claims 1-8, characterized in that, The conditions for the hydrodesulfurization treatment include: a reaction pressure of 2.0-24.0 MPa, a reaction temperature of 200-500℃, and a hydrogen-to-oil volume ratio of 50-5000 Nm. 3 / m 3 The liquid hourly space velocity is 0.1-30.0 h⁻¹. -1 .
14. The method according to claim 13, characterized in that, The conditions for the hydrodesulfurization treatment include: a reaction pressure of 3.0-10.0 MPa; a reaction temperature of 250-380℃; and a hydrogen-to-oil volume ratio of 200-2000 Nm. 3 / m 3 The liquid hourly space velocity is 0.2-10.0 h⁻¹. -1 .
15. The method according to any one of claims 1-8, characterized in that, The reaction conditions for catalytic cracking include: a reaction temperature of 500-680℃ and a weight hourly space velocity of 20-100 h⁻¹. -1 Alternatively, the reaction time may be 2-8 seconds, and the agent-to-oil weight ratio may be 5-12.
16. The method according to any one of claims 1-8, characterized in that, The mass ratio of propylene to propane in the reaction product is not less than 4.
17. The method according to claim 16, characterized in that, The mass ratio of propylene to propane in the reaction product is not less than 6.
18. The method according to claim 16, characterized in that, The mass ratio of propylene to propane in the reaction product is not less than 8.
19. The method according to any one of claims 1-8, characterized in that, The sulfur content in low-sulfur fuel oil components is no more than 0.1%.
20. The method according to claim 19, characterized in that, The sulfur content in low-sulfur fuel oil components is no more than 0.05%.
21. A system for producing multiple low-sulfur fuel oil components and low-carbon olefins, characterized in that, The system includes: The first fractionation tower is used to fractionate the feed oil at a fractionation temperature of 330~380℃ to obtain the light components and heavy components of the feed oil. A catalytic cracking reactor is used to carry out catalytic cracking reactions of heavy components of feedstock oil from the first fractionation tower within the catalytic cracking reactor to obtain reaction products; A separation system is used to separate the reaction products into catalytic cracking wax oil fraction, low-carbon olefins, and light gasoline fraction, wherein the final boiling point of the light gasoline fraction is not greater than 120°C and / or the olefin content is not less than 50% v%; wherein the light gasoline fraction outlet pipeline of the separation system is connected to the catalytic cracking reactor of the catalytic cracking reaction unit, so that the light gasoline fraction is returned to the catalytic cracking reactor; The hydrodesulfurization unit is used to perform hydrodesulfurization treatment on catalytic cracking wax oil fractions and light components of feedstock oil to obtain low-sulfur fuel oil components.
22. The system according to claim 21, characterized in that, The separation system includes: The product fractionation tower is used to separate the reaction products into dry gas fraction, liquefied gas fraction, gasoline fraction, light circulating oil fraction, catalytic cracking wax oil fraction and oil slurry fraction. A liquefied petroleum gas (LPG) fractionation tower is used to separate LPG fractions to obtain propylene and butene. A gasoline fractionation tower is used to separate the gasoline fraction into a heavy gasoline fraction and a light gasoline fraction, wherein the outlet of the light gasoline fraction of the gasoline fractionation tower is connected to a feedstock inlet of the catalytic cracking reactor of the catalytic cracking unit, so that the light gasoline fraction is recycled back to the catalytic cracking reactor.
23. The system according to claim 22, characterized in that, The oil slurry fraction outlet of the product fractionation tower is connected to a feedstock inlet of the catalytic cracking reactor of the catalytic cracking unit, so that the oil slurry fraction is recycled back to the catalytic cracking reactor.
24. The system according to any one of claims 21 to 23, characterized in that, The feedstock oil is selected from petroleum hydrocarbons, other mineral oils, or mixtures thereof, wherein the petroleum hydrocarbons are selected from vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, hydrotreated wax oil, hydrotreated residue, hydrotreated heavy oil, or any mixture thereof, and the other mineral oils are selected from coal liquefaction oil, oil sands oil, shale oil, or any mixture thereof.