A method for producing low-sulfur marine residual fuel oil from low-sulfur high-condensate crude oil

Abstract

A method for producing low-sulfur marine residual fuel oil from low-sulfur, high-pour point crude oil comprises: the crude oil is contacted with a pretreatment agent for pretreatment to obtain a carbon deposit pretreatment agent and a pretreatment reaction product; the carbon deposit pretreatment agent is charred and recycled, and the pretreatment reaction product is separated to obtain gas, naphtha, distillate oil, and residue; the gas, naphtha, and distillate oil are contacted with a catalytic cracking catalyst for a catalytic cracking reaction to obtain a carbon deposit catalyst and catalytic cracking products; the catalytic cracking products are separated to obtain dry gas, liquefied gas, gasoline, diesel, and slurry oil; the residue is mixed with the diesel and optionally the slurry oil for clarification to obtain low-sulfur marine residual fuel oil. This method solves the problem that low-sulfur, high-pour point crude oil cannot be used to produce low-sulfur marine residual fuel oil that meets national standards due to its high pour point; it has low investment costs and reduces other secondary processing costs.

Description

Technical Field

[0001] The invention relates to a method for producing low-sulfur marine residual fuel oil from low-sulfur high-condensation-point crude oil. Background Art

[0002] After January 1, 2020, according to the MAPPOL Convention, the sulfur content of marine fuel used by ships should not exceed 0.5%. At the same time, the People's Republic of China Marine Fuel Oil Standard GB17411-2015 stipulates various index requirements for low-sulfur marine residual fuel oil, among which RMG180 index requirements are sulfur content should not exceed 0.5%, pour point not exceeding 30°C, ash (mass fraction) not greater than 0.1%, vanadium content not exceeding 350mg / kg, and kinematic viscosity not exceeding 180mm. 2 / s.

[0003] Crude oil can be classified by sulfur content into four categories: ultra-low sulfur crude oil, low sulfur crude oil, sour crude oil, and high sulfur crude oil. Ultra-low sulfur crude oil and some low sulfur crude oils can theoretically be used to produce fuel oil with a sulfur content of less than 0.5% without desulfurization, but they must also meet other indicators specified in current marine fuel oil standards.

[0004] The hydrocarbon components of crude oil are primarily divided into alkanes, cycloalkanes, and aromatic hydrocarbons. Depending on the hydrocarbon composition, crude oil can be categorized into three types: paraffinic, cycloalkanes, and intermediate-base crude oils. Paraffinic crude oils contain more alkanes; cycloalkanes contain more cycloalkanes and aromatics; and intermediate-base crude oils fall somewhere in between. Currently, the majority of crude oil produced in China is low-sulfur paraffinic. Daqing crude oil, the most representative, has a low sulfur content, high wax content, and a high pour point. This allows the production of high-quality kerosene, diesel, solvent oil, lubricating oil, and commercial paraffin. However, it cannot produce low-sulfur marine residual fuel oil that meets marine fuel oil standards. This is primarily due to the high wax content and high pour point of low-sulfur paraffinic crude oil. Consequently, the atmospheric and vacuum residues produced by conventional atmospheric distillation (atmospheric distillation in refineries) and vacuum distillation (vacuum distillation in refineries) also have high pour points, making them unsuitable for large-scale use as low-sulfur marine residual fuel oil. Developing a process for producing low-sulfur marine residual fuel oil directly from low-sulfur paraffinic crude oil through a single process would significantly increase my country's refinery production capacity for this fuel. Currently, few refineries are capable of producing low-sulfur marine residual fuel oil that meets the latest standards, leaving a significant gap in the low-sulfur fuel oil market. Companies are eager for low-sulfur fuel oil production technology.

[0005] CN 110872533A discloses a low-sulfur heavy marine fuel oil and a preparation method thereof. The method comprises mixing the following raw materials by weight: 40-65 parts of residual oil, 5-15 parts of catalytic slurry oil, 5-20 parts of styrene tar, 5-20 parts of ethylene tar, 5-20 parts of diesel, 0.2-1 part of OP-10 additive, and 0.1-0.5 part of AES additive, according to the corresponding preparation steps, to obtain the low-sulfur heavy marine fuel oil. The residual oil is hydrogenated residual oil, a secondary processed product of atmospheric residue oil and vacuum residue oil, and has high production costs.

[0006] CN 110982561A discloses a residual marine fuel oil and its production method. The fuel is prepared from the following raw materials: 35 to 60 parts by weight of vacuum residue oil; 25 to 32 parts by weight of medium-temperature coal tar; 5 to 15 parts by weight of coal diesel oil; 10 to 25 parts by weight of refined wax oil; and 2 to 10 parts by weight of lubricant regeneration oil. The fuel contains a large amount of secondary processed oil, such as refined wax oil. The production cost is high, and the blending components are numerous.

[0007] Existing technologies primarily focus on producing marine residual fuel oil by directly blending residual oil or hydrotreated residual oil with a large amount of secondary processed oil. This results in high production costs and the need for multiple blending components. There are no reports in the literature on how to produce marine residual fuel oil using low-sulfur, high-pour point crude oil. Summary of the Invention

[0008] The object of the present invention is to provide a method for producing low-sulfur marine residual fuel oil from low-sulfur high-condensation point crude oil.

[0009] The method includes:

[0010] (1) the crude oil is contacted with a pretreatment agent to perform a pretreatment reaction to obtain a carbon deposition pretreatment agent and a pretreatment reaction product;

[0011] (2) separating the pretreatment reaction product to obtain gas, naphtha, distillate oil and residue;

[0012] (3) sending the carbon deposit pretreatment agent into a resurrection device for charring and semi-regeneration, and returning the charred pretreatment agent to the pretreatment reactor for recycling as a pretreatment agent;

[0013] (4) The gas, naphtha, and distillate oil are used as catalytic cracking feedstock oils, contacted with a catalytic cracking catalyst to carry out a catalytic cracking reaction, and the resulting reaction mixture is subjected to oil separation in a settler to obtain a carbonized catalyst and catalytic cracking products;

[0014] (5) The catalytic cracking products are separated to obtain dry gas, liquefied gas, gasoline, diesel and slurry oil;

[0015] (6) sending the carbonized catalyst into a regenerator for burning and regeneration, and returning the regenerated catalyst to the catalytic cracking reactor for recycling as a catalytic cracking catalyst;

[0016] (7) The residue in step (3) is used as low-sulfur marine residual fuel oil or a component of low-sulfur marine residual fuel oil.

[0017] The sulfur content of the crude oil is less than 0.5% by weight and the freezing point is greater than 30°C.

[0018] The pretreatment agent includes inorganic oxides, optional clay and optional large-pore zeolite, and the weight of each component in the total weight of the pretreatment agent is: 5-95 weight% of inorganic oxides, 0-95 weight% of clay, and 0-40 weight% of zeolite. The inorganic oxide includes at least one selected from aluminum oxide, silicon oxide, etc., the clay includes at least one selected from kaolin, montmorillonite, hydrotalcite, and montmorillonite, and the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silica Y.

[0019] The catalytic cracking catalyst contains large-pore zeolite and optional medium-pore zeolite, wherein the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silicon Y, and the medium-pore zeolite includes at least one selected from ZSM series zeolite, ZRP zeolite, and Beta zeolite.

[0020] The activity of the pretreatment agent is 5-40%, and the sum of the nickel content and the vanadium content in the pretreatment agent is 10,000-100,000 micrograms / gram.

[0021] The activity of the catalytic cracking catalyst is 50-70%, and the sum of the nickel content and the vanadium content on the catalytic cracking catalyst is 100-10000 micrograms / gram.

[0022] The activity is determined according to the method for determining the micro-reaction activity index of catalytic cracking catalysts NB / SH / T 0952-2017.

[0023] The operating conditions of the pretreatment reaction include: reaction temperature of 200-450° C.; reaction time of 1-20 seconds; weight ratio of pretreatment agent to crude oil of 3-15:1; and weight ratio of water vapor to crude oil of 0.01-0.5:1.

[0024] The operating conditions of the catalytic cracking reaction include: reaction temperature of 450-700°C; reaction time of 1-20 seconds; weight ratio of catalyst to catalytic cracking feedstock oil of 5-30:1; weight ratio of water vapor to catalytic cracking feedstock oil of 0.03-1:1.

[0025] The semi-regenerated fluidizing medium used in the resurrection vessel includes air and dilution gas, and the dilution gas can be selected from carbon dioxide, nitrogen, and catalytic cracking flue gas containing carbon dioxide and nitrogen. The carbon content of the obtained semi-regenerated pretreatment agent is controlled to be 0.5-3.0% by weight, and the oxygen content in the flue gas of the resurrection vessel is less than 0.1% by volume.

[0026] The residue in step (3) is used as a low-sulfur marine residual fuel oil component and mixed with other marine residual fuel oil blending components, where the other marine residual fuel oil blending components are selected from at least one of hydrogenated heavy oil, hydrogenated diesel, catalytic diesel, coker diesel, catalytic recycled oil, desolidified catalytic oil slurry, hydrogenated catalytic diesel, and coal tar.

[0027] 80-90 wt% of the residue is mixed with 5-15 wt% of the diesel and 0-5 wt% of the slurry oil to produce low-sulfur marine residual fuel oil.

[0028] Compared with the traditional method for producing low-sulfur marine residual fuel oil, the present invention has the following effects:

[0029] 1. Low-sulfur, high-pour point crude oil is first exposed to the pretreatment agent for a pretreatment reaction, significantly lowering the pour point of the residue while also reducing metal content, sulfur content, and acid value. The product yield of the pretreated low-sulfur, high-pour point crude oil is roughly equivalent to that obtained by fractionating the untreated low-sulfur, high-pour point crude oil over the same distillation range. During stable operation, the pretreatment agent concentrates a significant amount of metals in the crude oil, resulting in extremely low activity and cracking capacity. It does not significantly crack the major hydrocarbons in the crude oil, but it can slightly crack a small amount of linear alkanes in the crude oil's heavy components, transferring them to the crude oil's light components. This also causes some carbon-sulfur bonds and other heteroatom-containing bonds to break, thereby lowering the pour point of the crude oil's heavy components.

[0030] 2. The pretreatment agent can be prepared at low cost to improve its metal accommodating capacity, and can also be obtained directly by secondary treatment of catalytic cracking catalyst discarded from refineries, with extremely low cost.

[0031] 3. The crude oil pretreatment unit can also serve as the refinery's catalytic cracking unit. After the refinery uses crude oil residue to produce marine fuel oil, the heavy oil feed required for the secondary heavy oil processing unit is insufficient. In a refinery with multiple catalytic cracking units, one of the catalytic cracking units may be idle, which can be used as a crude oil pretreatment reaction unit. Alternatively, a new crude oil pretreatment reaction unit can be built.

[0032] 4. The carbon deposit pretreatment agent in the crude oil pretreatment unit uses air and diluent gas as regeneration media for semi-regeneration. The diluent gas can be selected from the regeneration flue gas of the catalytic cracking unit, which can greatly reduce energy consumption. The semi-regeneration process conditions ensure that the pretreatment agent always contains a certain proportion of coke. It is not easy to form high-oxidation valence polluting metal oxides, such as vanadium pentoxide, on the pretreatment agent, which slows down the toxic effect of metals enriched on the pretreatment agent and ensures the long-term stable use of the pretreatment agent.

[0033] 5. The gas, naphtha and distillate oil in the low-sulfur and high-freezing-point crude oil produced in the pretreatment reaction can be directly fed into another catalytic cracking unit for secondary conversion. The low-value catalytic diesel (LCO) and slurry oil produced can be mixed with the residue in the crude oil to produce low-sulfur marine residual fuel oil, thereby increasing the output of fuel oil produced directly from crude oil.

[0034] The method of the present invention solves the problem that low-sulfur high-freezing-point crude oil cannot be used in large quantities to produce low-sulfur marine residual fuel oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 The present invention provides a flow chart of a method for producing low-sulfur marine residual fuel oil from low-sulfur high-freezing point crude oil.

[0037] The following are the descriptions of the reference numerals:

[0038] 1 (low sulfur high pour point crude oil) pipeline

[0039] 2 (gas) pipelines

[0040] 3 (Naphtha) pipeline

[0041] 4 (distillate oil) pipeline

[0042] 5 (residue) pipeline

[0043] 6 (Dry Gas) Pipeline

[0044] 7 (liquefied gas) pipeline

[0045] 8 (Gasoline) pipeline

[0046] 9 (diesel) pipeline

[0047] 10 (slurry) pipeline

[0048] 11 (Low-sulfur marine residual fuel oil) pipeline

[0049] 12 (air used by the resurrection device) pipeline

[0050] 13 (Dilution gas used in resurrection device) pipeline

[0051] 14 (Resurrection device flue gas) pipeline

[0052] 15 (air used by regenerator) pipeline

[0053] 16 (Flue gas from catalytic cracking regenerator) pipeline

[0054] 50 Crude oil pretreatment reactor

[0055] 51 Resurrection Device

[0056] 52 (semi-regenerated pretreatment agent) pipeline

[0057] 53 (carbon deposit pretreatment agent) pipeline

[0058] 54 (pretreatment reaction product) pipeline

[0059] 60 Catalytic Cracking Reactor

[0060] 61 Regenerator

[0061] 62 (catalytic cracking regeneration catalyst) pipeline

[0062] 63 (carbon deposit catalyst) pipeline

[0063] 64 (catalytic cracking products) pipeline

[0064] 71 First product separation system

[0065] 72 Second product separation system

[0066] 80 Fuel oil mixing tank DETAILED DESCRIPTION

[0067] The inventors have discovered that the atmospheric residue produced by distilling low-sulfur, high-pour point crude oil directly through a refinery's atmospheric distillation tower has a pour point greater than 50°C. Even when this atmospheric residue is mixed with No. -10 catalytic diesel in a 50:50 ratio, the pour point remains greater than 45°C. The yield of atmospheric residue after distillation of crude oil is generally between 40% and 70%. As the primary processed product, it accounts for nearly half of the total, making it difficult for refineries to combine it with other secondary processed oils (such as catalytic diesel, slurry oil, and hydrotreated diesel) to produce low-sulfur marine residual fuel oil. Therefore, it is impossible to directly use low-sulfur, high-pour point crude oil in a refinery's atmospheric and vacuum tower systems to produce standard low-sulfur marine residual fuel oil.

[0068] At the same time, the inventors further discovered that by finely segmenting and cutting low-sulfur, high-pour point crude oil, the components with higher pour points and pour points are mainly concentrated in the heavy components above 330°C in the crude oil, which have the highest wax content and the largest molecular weight, but it is also difficult to remove the wax directly.

[0069] However, the inventors unexpectedly discovered that reacting low-sulfur, high-pour point crude oil with spent catalytic cracking catalyst from a refinery's catalytic cracking unit at a relatively low reaction temperature significantly lowers the pour point of the residual oil separated from the resulting reaction product. Further research revealed that the spent catalytic cracking catalyst was subjected to a hydrothermal deactivation treatment exceeding conventional levels and a metal contamination deactivation treatment exceeding conventional levels, reducing the activity of the spent catalyst to the limit, approaching that of an inert medium. The spent catalytic cracking catalyst, which had undergone a secondary treatment exceeding conventional levels, was used as a pretreatment agent in a pretreatment reaction with low-sulfur, high-pour point crude oil. The yields of naphtha, distillate, and residue in the resulting reaction product were similar to those obtained by direct atmospheric distillation of the low-sulfur, high-pour point crude oil without pretreatment. However, the pour point of the residue from the former was significantly lower than that of the residue from direct distillation of the low-sulfur, high-pour point crude oil. Furthermore, the metal content, sulfur content, and acid value of the residue from the former were also unexpectedly significantly reduced.

[0070] The method provided by the present invention for producing low-sulfur marine residual fuel oil from low-sulfur high-condensate-point crude oil comprises:

[0071] (1) the crude oil is contacted with a pretreatment agent to perform a pretreatment reaction to obtain a carbon deposition pretreatment agent and a pretreatment reaction product;

[0072] (2) separating the pretreatment reaction product to obtain gas, naphtha, distillate oil and residue;

[0073] (3) sending the carbon deposit pretreatment agent into a resurrection device for charring and semi-regeneration, and returning the charred pretreatment agent to the pretreatment reactor for recycling as a pretreatment agent;

[0074] (4) The gas, naphtha, and distillate oil are used as catalytic cracking feedstock oils, contacted with a catalytic cracking catalyst to carry out a catalytic cracking reaction, and the resulting reaction mixture is subjected to oil separation in a settler to obtain a carbonized catalyst and catalytic cracking products;

[0075] (5) The catalytic cracking products are separated to obtain dry gas, liquefied gas, gasoline, diesel and slurry oil;

[0076] (6) sending the carbonized catalyst into a regenerator for burning and regeneration, and returning the regenerated catalyst to the catalytic cracking reactor for recycling as a catalytic cracking catalyst;

[0077] (7) The residue in step (3) is used as low-sulfur marine residual fuel oil or a component of low-sulfur marine residual fuel oil.

[0078] The following is combined with Figure 1 The method provided by the present invention is further described, but the present invention is not limited thereby.

[0079] Figure 1 Among them, 50 is a pretreatment reactor, 51 is a resurrection reactor, 60 is a catalytic cracking reactor, 61 is a regenerator, 71 is a first product separation system, 72 is a second product separation system, and 80 is a fuel oil mixing tank.

[0080] After being heated, the desalted and dehydrated low-sulfur, high-pour point crude oil enters pretreatment reactor 50 via pipeline 1. It then comes into contact with the pretreatment agent from pipeline 52 for a pretreatment reaction, which absorbs metals from the crude oil, converts some of the sulfides, deacidifies, and lowers the pour point. This produces a carbon deposit pretreatment agent and a pretreatment reaction product. The pretreatment reaction product is introduced into first product separation system 71 via pipeline 54 for separation, yielding gas, naphtha, distillate oil, and residue, which are then withdrawn via pipelines 2, 3, 4, and 5, respectively. The carbon deposit pretreatment agent is then fed into resurrection vessel 51 via pipeline 53. Air and dilution gas 13 are simultaneously introduced into resurrection vessel 51 via pipelines 12 and 13, respectively, for charring and semi-regeneration. The semi-regenerated pretreatment agent is then returned to pretreatment reactor 50 via pipeline 52 for recycling. The resulting flue gas is withdrawn via pipeline 14 and discharged after desulfurization, denitrification, and dust removal.

[0081] Gas, naphtha, and distillate are fed into catalytic cracking reactor 60 via pipelines 2, 3, and 4, respectively, where they contact catalytic cracking catalyst from pipeline 62 for a catalytic cracking reaction. The resulting reaction mixture undergoes oil-agent separation in a settler, yielding carbonized catalyst and catalytic cracking products. The catalytic cracking products are introduced into second product separation system 72 via pipeline 64 for separation, yielding dry gas, liquefied petroleum gas, gasoline, diesel, and slurry oil, respectively, which are withdrawn via pipelines 6, 7, 8, 9, and 10. The carbonized catalyst is fed into regenerator 61 via pipeline 63. Air is simultaneously introduced into regenerator 61 via pipeline 15 for char regeneration. The regenerated catalyst is returned to the catalytic cracking reactor via pipeline 62 for recycling as catalytic cracking catalyst. The resulting flue gas is withdrawn via pipeline 16, desulfurized, denitrified, and dust-removed before being discharged.

[0082] The residue is sent to the fuel oil mixing tank 80 via pipeline 5, and part or all of the diesel and optional part or all of the slurry oil are sent to the fuel oil mixing tank 80 via pipelines 9 and 10 respectively for mixing and clarification to obtain low-sulfur marine residual fuel oil, which is then drawn out via pipeline 11.

[0083] According to the present invention, the properties of the low-sulfur and high-pour point paraffin-based crude oil are preferably a sulfur content of less than 0.5% by weight, a pour point greater than 30° C., and a crude oil wax content of 22-35% by weight.

[0084] According to the present invention, the pretreatment agent includes an inorganic oxide, optional clay and optional large-pore zeolite, wherein the inorganic oxide includes at least one selected from alumina, silica, etc., the clay includes at least one selected from kaolin, montmorillonite, hydrotalcite, trochosite, etc., and the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silica Y.

[0085] According to the present invention, the catalytic cracking catalyst contains large-pore zeolite and optional medium-pore zeolite, wherein the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silicon Y, and the medium-pore zeolite includes at least one selected from ZSM series zeolite, ZRP zeolite, and Beta zeolite.

[0086] The activity of the semi-regenerated pretreatment agent is 5-40%, and the sum of the nickel content and the vanadium content of the pretreatment agent is 10,000-100,000 micrograms / gram.

[0087] According to the present invention, the activity of the catalytic cracking regeneration catalyst is 50-70%, and the sum of the nickel content and the vanadium content on the catalytic cracking regeneration catalyst is 100-10000 μg / g.

[0088] According to the present invention, the operating conditions of the pretreatment reaction include: a reaction temperature of 200-450°C; a reaction time of 1-20 seconds; a weight ratio of the pretreatment agent to the crude oil (referred to as the agent-oil ratio) of 3-15:1; and a weight ratio of water vapor to the crude oil (referred to as the water-oil ratio) of 0.01-0.5:1.

[0089] The pretreatment reactor is selected from one or a combination of two or more of a riser reactor, a fluidized bed reactor, a fast bed reactor, a turbulent bed reactor, a bubbling bed reactor, and a fixed fluidized bed.

[0090] According to the present invention, the operating conditions of the catalytic cracking reaction include: a reaction temperature of 450-700°C; a reaction time of 1-20 seconds; a weight ratio of catalyst to catalytic cracking feedstock oil (referred to as catalyst-oil ratio) of 5-30:1; and a weight ratio of water vapor to catalytic cracking feedstock oil (referred to as water-oil ratio) of 0.03-1:1.

[0091] The catalytic cracking reactor is selected from one or a combination of two or more of a riser reactor, a fluidized bed reactor, a fast bed reactor, a turbulent bed reactor, a bubbling bed reactor, and a fixed fluidized bed.

[0092] According to the present invention, the semi-regenerated fluidizing medium used in the resurrection vessel comprises air and a diluent gas, wherein the diluent gas can be selected from carbon dioxide, nitrogen, and flue gas from a catalytic cracking unit containing carbon dioxide and nitrogen. The carbon content of the obtained semi-regenerated pretreatment agent is controlled to be 0.5-3.0% by weight, and the oxygen content in the flue gas of the resurrection vessel is less than 0.1% by volume.

[0093] In one embodiment, the method of the present invention further comprises:

[0094] Optionally, the low-sulfur marine residual fuel oil is mixed with other marine residual fuel oil blending components to increase the yield of marine residual fuel oil. The other marine residual fuel oil blending components can be selected from at least one of hydrogenated heavy oil, hydrogenated diesel, catalytic diesel, coker diesel, catalytic recycled oil, desolidified catalytic oil slurry, hydrogenated catalytic diesel, coal tar, etc.

[0095] To obtain low-sulfur marine residual fuel oil, when the residue is mixed with the diesel and the slurry oil, the mixing ratio is preferably: 80-90 weight %: 5-15 weight %: 0-5 weight %.

[0096] The method provided by the present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0097] The catalytic cracking catalyst used in the following examples and comparative examples is a cracking catalyst with the trade name SGC-1 produced by the Qilu Branch of Sinopec Catalyst Co., Ltd. Its specific properties are shown in Table 1. The catalyst contains an ultrastable Y molecular sieve containing rare earth.

[0098] The pretreatment agent used in the following examples was prepared from discarded SGC-1 balance agent discharged from an industrial catalytic cracking unit. The pretreatment agent required for the experiments was obtained using a cyclic contamination aging treatment method to simulate the properties of the pretreatment agent in industrial operation. The specific operation method is as follows:

[0099] Prepare 3290g of nickel naphthenate (the mass fraction of Ni in the liquid is 8%) and 4430g of vanadium naphthenate (the mass fraction of V in the liquid is 2%), pour them into 38.6kg of catalytic cracking diesel, stir and dissolve them evenly, and obtain the metal-containing catalytic cracking diesel feedstock required for the experiment.

[0100] Approximately 10 kg of spent SGC-1 balance was loaded into a continuously operated medium-sized catalytic cracking unit. The riser reactor had an inner diameter of 16 mm and a height of 3,800 mm. The SGC-1 balance continuously circulated between the reactor and the regenerator. The SGC-1 balance, at a temperature of 700°C, from the regenerator passed through a catalyst delivery ramp into the bottom of the riser reactor, where it flowed upward under the influence of pre-lift steam. Metal-containing catalytically cracked diesel feedstock was injected into the riser through a feed nozzle, where it came into contact with the hot SGC-1 balance to undergo a catalytic cracking reaction, depositing metallic nickel and vanadium on the SGC-1 balance. The post-reaction oil and gas from the riser reactor and the coked SGC-1 balance were separated in a settler. The separated SGC-1 balance then flowed by gravity into the stripping zone for stripping. After stripping, the carbon-deposited SGC-1 balance agent is fed into the regenerator through the spent agent delivery pipe. It then comes into contact with heated air and undergoes regeneration at 700°C. The hot SGC-1 balance agent is then returned to the catalytic cracking reactor for recycling and decontamination. The flue gas generated by the regenerator is then discharged. After the entire metal-containing catalytic cracking diesel feedstock is fed, the metal-contaminated SGC-1 balance agent is continuously circulated between the reactor and the regenerator for an additional 72 hours for further hydrothermal deactivation, ultimately yielding the pretreatment agent SGC-Deactivation A.

[0101] The same method was used to obtain pretreatment agents SGC-inactivated B and SGC-inactivated C. Their specific properties are shown in Table 2.

[0102] Example 1

[0103] Example 1 illustrates the effect of the method provided by the present invention on producing low-sulfur marine residual fuel oil from low-sulfur high-freezing point crude oil.

[0104] Two continuously operated medium-sized devices were used for the experiment, and the test was operated in a single-pass mode.

[0105] The first medium-sized device is used as a crude oil pretreatment reaction device, including a pretreatment reactor and a resurrection device. The pretreatment reactor is a riser with an inner diameter of 16 mm and a height of 3,800 mm.

[0106] The pretreatment agent, at a temperature of 640°C, flows from the resurrection vessel through a pretreatment agent delivery sloping pipe into the bottom of the pretreatment reactor riser, where it flows upward under the influence of pre-lift steam. Crude oil is heated to 190°C in a preheating furnace, mixed with atomized steam, and then sprayed into the pretreatment reactor riser through a feed nozzle, where it comes into contact with the hot pretreatment agent for a pretreatment reaction. The pretreatment reaction product and the coke pretreatment agent flow from the outlet of the pretreatment reactor riser into a settler for rapid separation. The coke pretreatment agent then enters the stripping zone for stripping. After stripping, the coke pretreatment agent enters the resurrection vessel through a coke pretreatment agent delivery pipe. Heated air mixed with a dilution gas rich in nitrogen and carbon dioxide enters the bottom of the resurrection vessel, where it comes into contact with the coke pretreatment agent and undergoes semi-regeneration at approximately 650°C. The hot pretreatment agent is then returned to the pretreatment reactor for recycling. The pretreatment reaction product exits the settler and is introduced into the primary product separation system for product separation, yielding gas and various liquid fractions (fractionated into naphtha, distillate, and residue).

[0107] The second medium-sized unit is used as a catalytic cracking unit, including a catalytic cracking reactor and a regenerator. The catalytic cracking reactor is a composite reactor consisting of a riser and a fluidized bed. The inner diameter of the riser reactor is 16 mm and the height is 3200 mm. The inner diameter of the fluidized bed reactor is 64 mm and the height is 600 mm. The outlet of the riser reactor is connected to the fluidized bed reactor.

[0108] The 670°C catalytic cracking catalyst from the regenerator enters the bottom of the riser in the catalytic cracking complex reactor through a catalyst delivery inclined pipe and flows upward under the action of pre-lift steam. Gas, naphtha, and distillate from the crude oil pretreatment reactor are sequentially injected into the riser through feed nozzles, where they come into contact with the hot catalytic cracking catalyst and initiate the catalytic cracking reaction. Gas is injected into the bottom of the riser, while naphtha is preheated to 60°C, mixed with atomized steam, and injected into the lower portion of the riser. Distillate is preheated to 250°C, mixed with atomized steam, and injected into the lower portion of the riser. The reaction oil-catalyst mixture from the riser reactor is introduced into a fluidized bed reactor at the riser outlet for further reaction. After the reaction, the gas and coked catalyst pass through the fluidized bed reactor and are separated in a settler. The separated coked catalyst then flows by gravity into the stripping zone for stripping. After stripping, the carbonized catalyst enters the regenerator through the spent catalyst delivery pipe, where it comes into contact with heated air and undergoes regeneration at 690°C. The hot regenerated catalyst is returned to the catalytic cracking reactor for recycling, and the flue gas generated by the regenerator is discharged. The post-reaction oil and gas (catalytic cracking products) are drawn from the settler and introduced into the secondary product separation system for product separation, yielding dry gas, liquefied petroleum gas, gasoline, diesel, and slurry oil.

[0109] The first medium-sized unit uses dilution gas rich in nitrogen and carbon dioxide from the flue gas produced by the regenerator of the second medium-sized unit.

[0110] In Example 1, the low-sulfur, high-condensation-point crude oil used was crude oil from the Subei Oilfield, and its properties are shown in Table 1. The pretreatment agent used was SGC-deactivation A.

[0111] The residue is mixed with the diesel and the slurry oil for clarification to obtain low-sulfur marine residual fuel oil.

[0112] Other reaction conditions are shown in Table 4.

[0113] The properties of the low-sulfur marine residual fuel oil obtained by mixing are shown in Table 5.

[0114] Comparative Example 1

[0115] Comparative Example 1 illustrates the effect of producing low-sulfur marine residual fuel oil from low-sulfur high-freeze point crude oil using a conventional production scheme.

[0116] The experiment was conducted using a medium-sized atmospheric distillation unit with an inner diameter of 50 mm and a height of 1500 mm. The distillation tower was filled with packing and the bottom and bottom kettle were electrically heated.

[0117] Low-sulfur, high-pour point crude oil is fed into the bottom kettle of an atmospheric distillation unit, where it is heated and distilled at atmospheric pressure, sequentially separating naphtha and distillate. The remaining residue at the bottom of the kettle is atmospheric residue. The atmospheric distillation unit operates under the following conditions: a bottom and kettle temperature of 360°C and a top pressure of 101 kPa (absolute).

[0118] The obtained residue was used as low sulfur marine residual fuel oil, and its properties are shown in Table 5.

[0119] In Comparative Example 1, the low-sulfur, high-freezing-point crude oil used is crude oil from the Subei Oilfield, which is the same as that in Example 1. The properties are shown in Table 1.

[0120] Comparative Example 2

[0121] Comparative Example 2 illustrates the effect of producing low-sulfur marine residual fuel oil from low-sulfur high-freeze point crude oil using a conventional production scheme.

[0122] The first step of the implementation process is the same as that of Comparative Example 1, which is to send the low-sulfur, high-freezing-point crude oil into the atmospheric distillation device to cut out naphtha and distillate oil in sequence, and the remaining bottom of the kettle is the residue (atmospheric residue oil).

[0123] Meanwhile, in Comparative Example 2, the naphtha and distillate oil obtained in the first step are further fed into a medium-sized catalytic cracking unit for use.

[0124] The medium-sized catalytic cracking unit includes a catalytic cracking reactor and a regenerator, wherein the catalytic cracking reactor is a composite reactor consisting of a riser and a fluidized bed. The inner diameter of the riser reactor is 16 mm and the height is 3200 mm. The inner diameter of the fluidized bed reactor is 64 mm and the height is 600 mm. The outlet of the riser reactor is connected to the fluidized bed reactor.

[0125] The 670°C catalytic cracking catalyst from the regenerator enters the bottom of the riser in the catalytic cracking complex reactor through a catalyst delivery inclined pipe, where it flows upward under the action of pre-lift steam. Naphtha and distillate oil from the crude oil pretreatment reactor are sequentially injected into the riser through feed nozzles, where they come into contact with the hot catalytic cracking catalyst to initiate the catalytic cracking reaction. The naphtha is preheated to 60°C, mixed with atomized steam, and then injected into the lower portion of the riser. The distillate oil is preheated to 250°C, mixed with atomized steam, and then injected into the lower portion of the riser. The reaction oil-catalyst mixture from the riser reactor is introduced into the fluidized bed reactor at the riser outlet for further reaction. After the reaction, the oil, gas, and coked catalyst are separated in a settler in the fluidized bed reactor. The separated coked catalyst is then gravity-fed into the stripping zone for stripping. After stripping, the carbonized catalyst enters the regenerator through the spent catalyst delivery pipe, where it comes into contact with heated air and undergoes regeneration at 690°C. The hot regenerated catalyst is returned to the catalytic cracking reactor for recycling, and the flue gas generated by the regenerator is discharged. The post-reaction oil and gas (catalytic cracking products) are drawn from the settler and introduced into the secondary product separation system for product separation, yielding dry gas, liquefied petroleum gas, gasoline, diesel, and slurry oil.

[0126] The residue was mixed with the diesel and the slurry oil for clarification to obtain low-sulfur marine residual fuel oil. The properties of the low-sulfur marine residual fuel oil obtained by mixing are shown in Table 5.

[0127] Other reaction conditions are shown in Table 4.

[0128] In Comparative Example 2, the low-sulfur, high-freezing-point crude oil used is crude oil from the Subei Oilfield.

[0129] Example 2

[0130] Example 2 further illustrates the implementation effect of the method provided by the present invention for producing low-sulfur marine residual fuel oil from low-sulfur high-condensation-point crude oil.

[0131] The experimental apparatus, method and crude oil were the same as those in Example 1.

[0132] The difference is that the pretreatment agent used is SGC-inactivated B.

[0133] The reaction conditions are shown in Table 4.

[0134] The properties of the low-sulfur marine residual fuel oil obtained by mixing are shown in Table 5.

[0135] Example 3

[0136] Example 3 further illustrates the implementation effect of the method provided by the present invention for producing low-sulfur marine residual fuel oil from low-sulfur high-freezing point crude oil.

[0137] The experimental apparatus, method and crude oil were the same as those in Example 1.

[0138] The difference is that the pretreatment agent used is SGC-inactivated C.

[0139] The reaction conditions are shown in Table 4.

[0140] The properties of the low-sulfur marine residual fuel oil obtained by mixing are shown in Table 5.

[0141] Table 1

[0142] Catalyst name SCG-1 Chemical properties, weight % <![CDATA[Al2O3]]> 52.6 <![CDATA[Na2O]]> 0.14 <![CDATA[RE2O3]]> 3.2 Physical properties Pore ​​volume, mL / g 0.29 <![CDATA[Specific surface area, m 2 / g]]> 124 Apparent bulk density, g / mL 0.82 Catalyst carbon content, % 0.02 Particle size distribution, weight % 0~20μm 0.2 0~40μm 8.8 0~80μm 59.1 0~105μm 80.6 0~149μm 96.4 Activity, weight % 67 Metal content, μg / g Ni 4451 V 2135

[0143] Table 2

[0144] Pretreatment agent name SCG-inactivated A SCG-inactivated B SCG-inactivated C Pretreatment conditions Catalytic cracking diesel consumption, kg 38.6 82.4 89.8 Nickel naphthenate dosage, g 3290 7040 5920 Amount of vanadium naphthenate, g 4430 9430 6430 Hydrothermal inactivation time, h 72 72 72 Activity, weight % 18 15 13 Metal content, μg / g Ni 30452 60233 51054 V 10632 20915 14678

[0145] Table 3

[0146] Raw oil name Subei Oilfield Crude Oil Density (20℃), kg / m3 0.845 Elemental composition, weight % S 0.202 N 0.14 Gum, % 8.4 Asphaltene, % 0.2 Wax content, % 28.1 Residual carbon value, % 3.46 Freezing point, ℃ 35 Pour point, ℃ 39 Viscosity (80℃) 6.751 Viscosity (100℃) 6.081 Metal content, μg / g Fe 1.4 Ni 9.9 V 0.1 Na 3 Ca 0.8 Distillation range, ℃ IBP 175.7 5％ 229.1 10％ 258.9 30％ 354.3 50％ 447.3 64.7％ 548

[0147] Table 4

[0148]

[0149] Table 5

[0150]

[0151] As can be seen from Tables 4 and 5, Example 1 adopts the method provided by the present invention, using low-sulfur, high-condensation-point crude oil from the Subei Oilfield as raw material. Through the method provided by the present invention, low-sulfur marine residual fuel oil that meets the RMG180 index in GB17411-2015 can be produced, with a sulfur content of no more than 0.5% by weight and a pour point of no more than 30°C.

[0152] In Comparative Example 1, low-sulfur, high-pour point crude oil from the Subei Oilfield was used as raw material, and conventional distillation and cutting were used to produce low-sulfur residual fuel oil for marine use. The pour point was greater than 30°C and it could not be shipped. In Comparative Example 2, low-sulfur, high-pour point crude oil from the Subei Oilfield was used as raw material, and conventional distillation, cutting, and blending methods were used to produce low-sulfur residual fuel oil for marine use. The pour point was greater than 30°C and it could not be shipped.

[0153] In Example 2 and Example 3, the method provided by the present invention is adopted, and low-sulfur, high-condensation-point crude oil from the Subei Oilfield is used as raw material. By the method provided by the present invention, low-sulfur marine residual fuel oil that meets the RMG180 index in GB17411-2015 can also be produced.

[0154] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0155] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0156] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the spirit of the present invention, they should also be regarded as the content of the present invention.

Claims

1. A method for producing low-sulfur marine residual fuel oil from low-sulfur high-condensate crude oil, characterized in that: The method includes: (1) The crude oil is contacted with a pretreatment agent to perform a pretreatment reaction to obtain a carbon deposition pretreatment agent and a pretreatment reaction product; The pretreatment agent includes an inorganic oxide, an optional clay, and an optional large-pore zeolite, and the weight of each component accounts for 5-95% by weight of the inorganic oxide, 0-95% by weight of the clay, and 0-40% by weight of the zeolite. The inorganic oxide includes at least one selected from alumina and silica, the clay includes at least one selected from kaolin, montmorillonite, hydrotalcite, and trochosite, and the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silica Y. The activity of the pretreatment agent is 5-40%, and the sum of the nickel content and the vanadium content of the pretreatment agent is 10,000-100,000 μg / g; The operating conditions of the pretreatment reaction include: reaction temperature of 200-450°C; reaction time of 1-20 seconds; weight ratio of pretreatment agent to crude oil of 3-15:1; weight ratio of water vapor to crude oil of 0.01-0.5:1; (2) The pretreatment reaction product is separated to obtain gas, naphtha, distillate oil and residue; (3) sending the carbon deposit pretreatment agent into a resurrection device for charring and semi-regeneration, and returning the charred pretreatment agent to the pretreatment reactor for recycling as a pretreatment agent; (4) The gas, naphtha and distillate oil are used as catalytic cracking feedstock oils, contacted with a catalytic cracking catalyst to carry out a catalytic cracking reaction, and the resulting reaction mixture is subjected to oil separation in a settler to obtain a carbon deposited catalyst and catalytic cracking products; The catalytic cracking catalyst contains a large-pore zeolite and an optional medium-pore zeolite, wherein the large-pore zeolite includes at least one selected from Y, REY, HY, USY, and high-silicon Y, and the medium-pore zeolite includes at least one selected from ZSM series zeolite, ZRP zeolite, and Beta zeolite; (5) The catalytic cracking products are separated to obtain dry gas, liquefied gas, gasoline, diesel and slurry oil; (6) sending the carbonized catalyst into a regenerator for burning and regeneration, and returning the regenerated catalyst to the catalytic cracking reactor for recycling as a catalytic cracking catalyst; (7) The residue is mixed with the diesel and the slurry oil for clarification to obtain low-sulfur marine residual fuel oil.

2. The method according to claim 1, wherein the sulfur content of the crude oil is less than 0.5% by weight and the pour point is greater than 30°C.

3. The method according to claim 1, wherein The activity of the catalytic cracking catalyst is 50-70%, and the sum of the nickel content and the vanadium content on the catalytic cracking catalyst is 100-10000 μg / g.

4. The method according to claim 1, wherein The operating conditions of the catalytic cracking reaction include: reaction temperature of 450-700°C; reaction time of 1-20 seconds; weight ratio of catalyst to catalytic cracking feedstock oil of 5-30:1; weight ratio of water vapor to catalytic cracking feedstock oil of 0.03-1:

1.

5. The method according to claim 1, wherein The semi-regenerated fluidizing medium used in the resurrection vessel comprises air and dilution gas, wherein the dilution gas is selected from carbon dioxide, nitrogen, and catalytic cracking flue gas containing carbon dioxide and nitrogen. The carbon content of the semi-regenerated pretreatment agent is controlled to be 0.5-3.0% by weight, and the oxygen content in the flue gas of the resurrection vessel is less than 0.1% by volume.

6. The method according to claim 1, wherein 80-90 wt% of the residue is mixed with 5-15 wt% of the diesel and 0.65-5 wt% of the slurry oil to produce low-sulfur marine residual fuel oil.

Images