Method for producing feedstock oil for fluid catalytic cracking and method for fluid catalytic cracking

Abstract

To provide a raw oil for fluidized catalytic cracking which is obtained by hydrogen treatment of a fraction comprising a vacuum gas oil and a light oil, has a conversion ratio equivalent to or more as compared to a case where only a fraction obtained by hydrogen treatment of a fraction comprising only a vacuum gas oil is used as a raw oil for fluidized catalytic cracking, and a fluidized catalytic cracking method using the raw oil for fluidized catalytic cracking.SOLUTION: A raw oil for fluidized catalytic cracking, obtained by hydrogen treatment of a fraction comprising 1-60 vol.% of a fraction A which has a ratio of a fraction distilled at 350°C or over to a total volume of a fraction distilled at 350°C or under of 0.3 or over to the total volume, and 40-99 vol.% of a vacuum gas oil, is disclosed.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a feedstock for fluid catalytic cracking Manufacturing method and a fluid catalytic cracking method.

Background Art

[0002] A fluid catalytic cracking unit is a device that produces cracked oils with high added value, such as gasoline, kerosene, gas oil, and propylene and ethylene, which are petrochemical raw materials, by catalytically cracking a feedstock containing low-quality heavy oil obtained in the petroleum refining process. As the heavy oil, desulfurized vacuum gas oil obtained by subjecting vacuum gas oil obtained by vacuum distillation of atmospheric residue oil obtained by atmospheric distillation of crude oil in an atmospheric distillation unit to desulfurization treatment in an indirect desulfurization unit is used.

[0003] As a fluid catalytic cracking unit, a riser that contacts a feedstock with a fluid catalytic cracking catalyst to crack the feedstock and produce cracked oil, a reaction tower that separates the cracked oil and the fluid catalytic cracking catalyst, and a regeneration tower that regenerates the catalyst by burning carbon (coke) deposited on the separated fluid catalytic cracking catalyst are well-known (for example, Patent Document 1). The fluid catalytic cracking catalyst is a powdery solid catalyst, and for example, a solid catalyst containing zeolite as a main component is widely used (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Fluid catalytic cracking units are considered most profitable when operated at their maximum processing capacity. However, there may be shortages of vacuum diesel fuel, resulting in a shortage of desulfurized vacuum diesel fuel relative to the maximum processing capacity of the equipment.

[0006] The inventors of this application investigated how to compensate for the aforementioned deficiency by using a desulfurized fraction containing desulfurized vacuum gas oil, obtained by mixing vacuum gas oil with light oil and desulfurizing the resulting fraction in an indirect desulfurization unit. In this case, the inventors of this application expected that the conversion rate of the raw material oil would be about the same whether only desulfurized vacuum gas oil was used as the raw material oil in a fluid catalytic cracking unit or whether the desulfurized fraction containing the aforementioned desulfurized vacuum gas oil was used as the raw material oil in a fluid catalytic cracking unit. However, contrary to expectations, it was found that the conversion rate of the raw material oil was sometimes lower in the latter case than in the former case.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a feedstock for fluid catalytic cracking obtained by hydrogenating a fraction consisting of vacuum-reduced diesel and light oil, and a fluid catalytic cracking method using the said feedstock for fluid catalytic cracking, which has a conversion rate equal to or greater than that of a case in which only a fraction obtained by hydrogenating a fraction consisting only of vacuum-reduced diesel is used as the feedstock for fluid catalytic cracking. [Means for solving the problem]

[0008] To solve the above problems, the present invention has the following embodiments. [1] A feedstock for fluid catalytic cracking obtained by hydrothermating a fraction consisting of 1 to 60 volume percent of fraction A, in which the ratio of the total volume of fractions distilled at 350°C or above to the total volume of fractions distilled at 350°C or below is 0.3 or more, and 40 to 99 volume percent of vacuum diesel fuel. [2] The fluid catalytic cracking feedstock according to [1], wherein the content of the fraction distilled at 340 to 400°C relative to the total volume of the fluid catalytic cracking feedstock is 20 to 50% by volume. [3] The feedstock for fluid catalytic cracking according to [1] or [2], wherein fraction A includes fraction B which contains a straight-run gas oil fraction obtained by atmospheric distillation of crude oil, and the content of the straight-run gas oil fraction relative to the total volume of fraction B is 80 to 100% by volume. [4] A fluid catalytic cracking method comprising treating a raw material oil containing a raw material oil for fluid catalytic cracking described in any of [1] to [3] in a fluid catalytic cracking apparatus. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a feedstock for fluid catalytic cracking obtained by hydrogenating a fraction consisting of vacuum-reduced diesel and light oil, which has a conversion rate equal to or greater than that of a case where only a fraction obtained by hydrogenating a fraction consisting only of vacuum-reduced diesel is used as the feedstock for fluid catalytic cracking, and a fluid catalytic cracking method using the said feedstock for fluid catalytic cracking. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing a method for producing a raw material oil for fluid catalytic cracking according to one embodiment. [Figure 2] This is a diagram showing the configuration of a fluid catalytic cracking apparatus. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below, but the following description is merely one example of an embodiment of the present invention, and the present invention is not limited to these contents and can be modified and implemented within the scope of its gist.

[0012] <Definition> The term "boiling point range" refers to the range from the initial boiling point (IBP) to the end point (EP). IBP, EP, and X volume % distillation temperature (where X is greater than 0 and less than 100) can be measured in accordance with JIS K2254 (2018) "Petroleum products - Method for determining distillation properties". Sulfur content can be measured in accordance with JIS K 2541-4 (2003) "Crude oil and petroleum products - Test methods for sulfur content Part 4: Radiation excitation method".

[0013] The "straight-run gas oil fraction" means the gas oil fraction obtained by subjecting crude oil to atmospheric distillation in an atmospheric distillation unit. The boiling point range of the straight-run gas oil fraction is, for example, 200 to 460°C.

[0014] The "vacuum gas oil" means the heavy fraction among the gas oil fractions obtained by subjecting the atmospheric residue oil obtained by subjecting crude oil to atmospheric distillation in an atmospheric distillation unit to vacuum distillation in a vacuum distillation unit. The boiling point range of the vacuum gas oil is, for example, 250 to 600°C. The "light vacuum gas oil" means the light fraction among the gas oil fractions obtained by subjecting the atmospheric residue oil obtained by subjecting crude oil to atmospheric distillation in an atmospheric distillation unit to vacuum distillation in a vacuum distillation unit. The boiling point range of the light vacuum gas oil is, for example, 200 to 360°C.

[0015] The "desulfurized vacuum gas oil" means the heavy fraction among the fractions obtained by subjecting a fraction containing vacuum gas oil to desulfurization treatment in an indirect desulfurization unit. The boiling point range of the desulfurized vacuum gas oil is, for example, 200 to 600°C. The sulfur content relative to the total mass of the desulfurized vacuum gas oil is, for example, 0.05 to 0.5% by mass. The "desulfurized light vacuum gas oil" means the light fraction among the fractions obtained by subjecting a fraction containing vacuum gas oil to desulfurization treatment in an indirect desulfurization unit. The boiling point range of the desulfurized light vacuum gas oil is, for example, 160 to 370°C. The sulfur content relative to the total mass of the desulfurized light vacuum gas oil is, for example, 0.005 to 0.02% by mass.

[0016] ≪Feedstock for Fluid Catalytic Cracking≫ The feedstock for fluid catalytic cracking of the present embodiment is a feedstock for fluid catalytic cracking obtained by subjecting a fraction composed of 1 to 60% by volume of fraction A having a ratio of the total volume of the fraction distilled at 350°C or higher to the total volume of the fraction distilled at 350°C or lower of 0.3 or higher and 40 to 99% by volume of vacuum gas oil to hydrogenation treatment.

[0017] The content of fraction A is 1 to 60% by volume, preferably 1 to 50% by volume, and more preferably 3 to 35% by volume. When the content of fraction A is at least the lower limit of the above range, the throughput of fraction A, which is a light oil, is improved. When the content of fraction A is at most the upper limit of the above range, the conversion rate of the feedstock is improved.

[0018] The vacuum-reduced diesel content is 40 to 99% by volume, preferably 50 to 99% by volume, and more preferably 65 to 97% by volume. When the vacuum-reduced diesel content is above the lower limit of the above range, the conversion rate of the raw material oil improves. When the vacuum-reduced diesel content is below the upper limit of the above range, the processing volume of fraction A, which is light oil, improves.

[0019] The content of the fraction distilled at 340-400°C relative to the total volume of the feedstock for fluid catalytic cracking is preferably 20-50% by volume, more preferably 20-40% by volume, and even more preferably 25-40% by volume. If the content is above the lower limit of the above range, the conversion rate of the feedstock oil improves. If the content is below the upper limit of the above range, the fraction derived from vacuum diesel, which is the original FCC feedstock oil, becomes larger, and the benefits of cracking heavy fractions are more easily obtained.

[0020] The boiling point range of the feedstock oil for fluid catalytic cracking is, for example, 200 to 600°C, preferably 220 to 580°C, and more preferably 250 to 550°C. The 10% volume distillation temperature of the feedstock oil for fluid catalytic cracking is preferably 300-400°C, more preferably 320-380°C, and even more preferably 340-360°C. The 50% volume distillation temperature of the feedstock oil for fluid catalytic cracking is preferably 400-500°C, more preferably 420-480°C, and even more preferably 440-460°C. The 90% volume distillation temperature of the feedstock oil for fluid catalytic cracking is preferably 480-580°C, more preferably 490-560°C, and even more preferably 510-540°C. The sulfur content relative to the total mass of the feedstock oil for fluid catalytic cracking is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and even more preferably 0.1 to 0.3% by mass.

[0021] <Depressurized diesel fuel> The boiling point range of reduced-pressure diesel fuel is preferably 250 to 600°C, more preferably 260 to 580°C, and even more preferably 280 to 550°C. The 10% volume distillation temperature of reduced-pressure diesel fuel is preferably 300-400°C, more preferably 320-380°C, and even more preferably 340-360°C. The 50% volume distillation temperature of vacuum diesel is preferably 400-500°C, more preferably 420-480°C, and even more preferably 430-460°C. The 90% volume distillation temperature of reduced-pressure diesel fuel is preferably 480-580°C, more preferably 500-560°C, and even more preferably 510-540°C.

[0022] <Dividend A> Fraction A is a fraction in which the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower is 0.3 or higher. The ratio is preferably 0.5 or higher, more preferably 0.8 or higher, and even more preferably 1 or higher. The ratio is preferably 3 or lower, more preferably 2.5 or lower, and even more preferably 2 or lower. The upper and lower limits can be combined in any way. If the ratio is above the lower limit, the conversion rate of the raw material oil improves. For the purpose of this invention, which is to compensate for a deficiency in heavy components with light components, it is preferable that the ratio be below the upper limit.

[0023] The boiling point range of fraction A is preferably 200 to 500°C, more preferably 220 to 480°C, and even more preferably 250 to 450°C. The distillation temperature for 10% by volume of fraction A is preferably 280-380°C, more preferably 300-360°C, and even more preferably 320-340°C. The 50% volume distillation temperature of fraction A is preferably 320-420°C, more preferably 340-400°C, and even more preferably 340-360°C. The 90% volume distillation temperature of fraction A is preferably 350-450°C, more preferably 370-430°C, and even more preferably 390-410°C. There are no particular limitations on the sulfur content of fraction A, but if fraction A is derived from crude oil such as straight-run diesel, the sulfur content of fraction A relative to the total mass is preferably 0.5 to 1.5% by mass, more preferably 0.5 to 1.3% by mass, and even more preferably 0.5 to 1.1% by mass.

[0024] Fraction A is not particularly limited as long as it is a fraction in which the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower is 0.3 or higher.

[0025] Fraction A includes fractions containing straight-run diesel fuel obtained by atmospheric distillation of crude oil (hereinafter also referred to as "fraction B"), fractions containing light vacuum diesel fuel, fractions containing waste cooking oil, fractions containing FT synthetic oil, fractions containing plastic oil, etc., with fraction B being preferred. The boiling point range of the straight-run diesel fuel contained in fraction B is preferably 300°C or higher at a 10% volume distillation temperature, more preferably 310°C or higher, and even more preferably 320°C or higher.

[0026] The total content of straight-run diesel fuel relative to the total volume of fraction B is preferably 80 to 100% by volume, more preferably 82 to 100% by volume, and even more preferably 85 to 100% by volume.

[0027] The boiling point range of fraction B is, for example, 250 to 600°C, preferably 300 to 500°C, and more preferably 350 to 450°C. The 10% volume distillation temperature of fraction B is preferably 280-380°C, more preferably 300-360°C, and even more preferably 320-340°C. The 50% volume distillation temperature of fraction B is preferably 310 to 410°C, more preferably 330 to 390°C, and even more preferably 350 to 370°C. The 90% volume distillation temperature of fraction B is preferably 350-450°C, more preferably 370-430°C, and even more preferably 390-410°C.

[0028] <Method for producing raw material oil for fluid catalytic cracking> Figure 1 is a schematic diagram showing a method for producing a raw material oil for fluid catalytic cracking according to one embodiment. The method for producing a raw material oil for fluid catalytic cracking according to this embodiment will be described below with reference to Figure 1.

[0029] Figure 1 is a schematic diagram illustrating the method for producing the raw material oil for fluid catalytic cracking according to this embodiment. Crude oil is distilled at atmospheric pressure in an atmospheric pressure distillation unit 100 to obtain atmospheric pressure residue oil. The atmospheric pressure residue oil is distilled at reduced pressure in a reduced pressure distillation unit 200 to obtain reduced pressure diesel fuel. By mixing fraction A with the reduced pressure diesel fuel, mixed reduced pressure diesel fuel is obtained. The mixed reduced pressure diesel fuel consists of fractions of 1 to 60 volume percent of fraction A and 40 to 99 volume percent of the reduced pressure diesel fuel. The mixed reduced pressure diesel fuel is hydrotreated to obtain desulfurized mixed reduced pressure diesel fuel. Hydrotreatment can be carried out using a hydrotreatment apparatus known in this field. In Figure 1, an indirect desulfurization apparatus 300 is shown as an example of a hydrotreatment apparatus. The desulfurized mixed reduced pressure diesel fuel obtained in this way is the feedstock oil for fluid catalytic cracking in this embodiment.

[0030] In the above description, the desulfurized mixed vacuum gas oil obtained by desulfurizing mixed vacuum gas oil in an indirect desulfurization unit 300 was used as the feedstock for fluid catalytic cracking. However, the refined desulfurized mixed vacuum gas oil obtained by separating extremely light fractions such as gaseous components from the desulfurized mixed vacuum gas oil may also be used as the feedstock for fluid catalytic cracking. Alternatively, the desulfurized vacuum gas oil fraction may be separated into a heavy fraction (desulfurized vacuum gas oil) and a light fraction (desulfurized light vacuum gas oil), and the mixed fraction obtained by mixing the desulfurized vacuum gas oil, desulfurized light vacuum gas oil, and other fractions as needed may be used as the feedstock for fluid catalytic cracking.

[0031] The boiling point range of the mixed reduced-pressure diesel fuel is, for example, 250 to 600°C, preferably 260 to 590°C, and more preferably 270 to 580°C. The 10% volume distillation temperature of the mixed vacuum diesel fuel is preferably 300-400°C, more preferably 320-380°C, and even more preferably 340-360°C. The 50% volume distillation temperature of the mixed vacuum diesel fuel is preferably 350 to 450°C, more preferably 360 to 430°C, and even more preferably 380 to 420°C. The 90% volume distillation temperature of the mixed vacuum diesel fuel is preferably 450-550°C, more preferably 470-540°C, and even more preferably 490-530°C.

[0032] The boiling point range of the desulfurized mixed vacuum diesel fuel and the refined desulfurized mixed vacuum diesel fuel is, for example, 200 to 600°C, preferably 220 to 580°C, and more preferably 250 to 550°C. The 10% volume distillation temperature of the desulfurized mixed vacuum gas oil and the refined desulfurized mixed vacuum gas oil is preferably 300 to 400°C, more preferably 320 to 380°C, and even more preferably 340 to 360°C. The 50% volume distillation temperature of the desulfurized mixed vacuum gas oil and the refined desulfurized mixed vacuum gas oil is preferably 400 to 500°C, more preferably 420 to 480°C, and even more preferably 440 to 460°C. The 90% volume distillation temperature of the desulfurized mixed vacuum gas oil and the refined desulfurized mixed vacuum gas oil is preferably 480 to 580°C, more preferably 490 to 560°C, and even more preferably 510 to 540°C. The sulfur content relative to the total mass of the desulfurized mixed vacuum gas oil and the refined desulfurized mixed vacuum gas oil is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and even more preferably 0.1 to 0.3% by mass.

[0033] The boiling point range of desulfurized vacuum diesel is preferably 200 to 600°C, more preferably 220 to 580°C, and even more preferably 240 to 560°C. The 10% volume distillation temperature of desulfurized vacuum diesel is preferably 260-360°C, more preferably 280-340°C, and even more preferably 300-320°C. The 50% volume distillation temperature of desulfurized vacuum diesel is preferably 330-430°C, more preferably 350-410°C, and even more preferably 370-390°C. The 90% volume distillation temperature of desulfurized vacuum diesel is preferably 430-530°C, more preferably 450-510°C, and even more preferably 470-490°C. The sulfur content relative to the total mass of desulfurized vacuum diesel fuel is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and even more preferably 0.1 to 0.3% by mass.

[0034] The boiling point range of desulfurized light vacuum gas oil is preferably 160 to 370°C, more preferably 180 to 360°C, and even more preferably 210 to 360°C. The 10% volume distillation temperature of desulfurized light vacuum gas oil is preferably 220 to 320°C, more preferably 240 to 300°C, and even more preferably 260 to 280°C. The 50% volume distillation temperature of desulfurized light vacuum gas oil is preferably 260 to 360°C, more preferably 280 to 340°C, and even more preferably 300 to 320°C. The 90% volume distillation temperature of desulfurized light vacuum gas oil is preferably 290 to 370°C, more preferably 310 to 360°C, and even more preferably 330 to 350°C. The sulfur content relative to the total mass of desulfurized light vacuum gas oil is preferably 0.005 to 0.02% by mass, more preferably 0.005 to 0.015% by mass, and even more preferably 0.01 to 0.015% by mass.

[0035] When a desulfurized vacuum gas oil fraction is separated into desulfurized vacuum gas oil and desulfurized light vacuum gas oil, and the mixed fraction obtained by mixing the desulfurized vacuum gas oil, desulfurized light vacuum gas oil, and other fractions as needed is used as feedstock for fluid catalytic cracking, the total content of desulfurized vacuum gas oil and desulfurized light vacuum gas oil relative to the total volume of the feedstock for fluid catalytic cracking is preferably 60 to 100% by volume, more preferably 70 to 100% by volume, and even more preferably 80 to 100% by volume. The content of desulfurized vacuum gas oil relative to the total volume of feedstock oil for fluid catalytic cracking is preferably 30 to 80% by volume, more preferably 40 to 85% by volume, and even more preferably 50 to 80% by volume. The content of desulfurized light vacuum gas oil relative to the total volume of feedstock oil for fluid catalytic cracking is preferably 10 to 50% by volume, more preferably 10 to 40% by volume, and even more preferably 10 to 35% by volume. Examples of the other fractions include waste cooking oil, FT synthetic oil, plastic oil, etc. The content of the other fractions is preferably 0 to 40% by volume, more preferably 0 to 30% by volume, and even more preferably 0 to 20% by volume.

[0036] <Hydrogenation treatment> Hydrogenation can be carried out by methods known in this field. For example, it can be carried out by supplying the mixed vacuum diesel (raw material oil) and hydrogen to an indirect desulfurization apparatus equipped with an indirect desulfurization catalyst. The following will specifically describe the case where the hydrogenation is an indirect desulfurization treatment.

[0037] Examples of indirect desulfurization catalysts include alumina catalysts in which at least one metal selected from Group 6 of the periodic table and at least one metal selected from Group 9 or Group 10 of the periodic table, or both, are supported on an inorganic oxide support such as zeolite, boria, silica, zirconia, zinc oxide, or phosphorus oxide. The inorganic oxide support is preferably an alumina support, and more preferably a γ-alumina support. The Group 6 metal is preferably molybdenum. The Group 9 or Group 10 metal is preferably nickel or cobalt, and more preferably cobalt.

[0038] The hydrogen / raw material ratio is 100-1000 Nm³. 3 It is preferably / kL and 175~925Nm 3 It is more preferable that the value be / kL, and the range is 250-850 Nm 3 It is even more preferable that the value be / kL. The hydrogen partial pressure is preferably 3.5 to 10 MPa, and more preferably 4 to 9 MPa. If the hydrogen partial pressure is above the lower limit of the above range, the hydrogenation reaction proceeds more easily. The reaction temperature is preferably 330 to 430°C, and more preferably 350 to 410°C. If the reaction temperature is above the lower limit of the above range, the catalytic activity can be fully exhibited. If the reaction temperature is below the upper limit of the above range, the thermal decomposition of the heavy hydrocarbon oil proceeds appropriately, while catalyst degradation is less likely to occur. The reaction temperature refers to the average temperature of the catalyst bed. LHSV is 0.2-2 hours -1 Preferably, this is 0.5 to 2 hours. -1 It is preferable that it be so.

[0039] ≪Fluid catalytic cracking method≫ The fluid catalytic cracking method of this embodiment is a fluid catalytic cracking method in which a raw material oil containing the above-mentioned fluid catalytic cracking raw material oil is processed in a fluid catalytic cracking apparatus. The method for producing cracked oil according to this embodiment is a method for producing cracked oil by processing a raw material oil containing the above-mentioned raw material oil for fluid catalytic cracking in a fluid catalytic cracking apparatus. Hereinafter, the raw material oil for fluid catalytic cracking described above will also be referred to as "raw material oil 1," and the raw material oil containing the above-mentioned raw material oil 1 will also be referred to as "raw material oil 2."

[0040] <Fluid catalytic cracking equipment> The fluid catalytic cracking apparatus (hereinafter also referred to as the "FCC apparatus") of this embodiment is equipped with a fluid catalytic cracking catalyst. It comprises a riser that produces cracked oil by contacting the fluid catalytic cracking catalyst with the raw material oil 2 to crack the raw material oil 2, a reaction tower that separates the cracked oil from the fluid catalytic cracking catalyst, and a regeneration tower that regenerates the catalyst by burning the carbon (coke) deposited on the separated fluid catalytic cracking catalyst. An example of the FCC apparatus of this embodiment will be described below with reference to Figure 3. Figure 3 is a configuration diagram showing an example of the FCC apparatus. The FCC apparatus 1 comprises a riser 10, a reaction tower 20, and a regeneration tower 30.

[0041] (Riser) The riser 10 is a device that produces cracked oil by contacting the feed oil 2 with a fluid catalytic cracking catalyst and cracking the feed oil 2. The riser 10 is connected to, for example, a regenerated catalyst transfer line 34 that supplies the fluid catalytic cracking catalyst regenerated in the regeneration tower 30, and a feed oil supply line 11 that supplies the feed oil 2. A preheating device 12 is also provided on the feed oil supply line. Furthermore, the riser 10 is connected to the reaction tower 20 above.

[0042] (Reaction tower) The reaction tower 20 is a device for separating the cracked oil from the fluid catalytic cracking catalyst. The reaction tower 20 includes, for example, a cyclone 21, a cracked oil discharge line 22, a stripper 23, and a post-reaction catalyst transfer line 24. The upper part of the cyclone 21 is connected to the cracked oil discharge line 22. Furthermore, the bottom of the stripper 23 and the lower part of the regeneration tower 30 are connected by a post-reaction catalyst transfer line 24.

[0043] (Regeneration Tower) The regeneration tower 30 is a device that regenerates the catalyst by burning the coke on the fluid catalytic cracking catalyst separated in the reaction tower 20. The regeneration tower 30 includes, for example, an air blower 31, an air grid 32, a cyclone 33, a regenerated catalyst transfer line 34, and an exhaust gas line 35. The bottom of the regeneration tower and the air blower 31 are connected via the air grid 32. Furthermore, a cyclone 33 is installed at the top of the regeneration tower, and the top of the cyclone 33 is connected to the exhaust gas line 35.

[0044] (Refining equipment) The reaction tower 20 of the fluid catalytic cracking unit 1 is preferably connected to a refining facility (not shown) via a cracked oil discharge line 22. The refining facility is equipment that separates the cracked oil produced in the FCC unit into gasoline, kerosene, diesel fuel, and petrochemical raw materials, and is, for example, a distillation tower.

[0045] <Fluid catalytic cracking catalyst> Examples of the fluid catalytic cracking catalyst (hereinafter also referred to as "FCC catalyst") of this embodiment include a fluid catalytic cracking catalyst composed of a zeolite having decomposition activity, an inorganic oxide such as alumina or a viscosity mineral as a matrix component, and a binder that combines these. The zeolite preferably includes zeolites having a sodalite cage structure, β-zeolite, ZSM-5 type zeolite, and more preferably zeolites having a sodalite cage structure. The zeolite having a sodalite cage structure can be one or more selected from sodalite, type A zeolite, EMT, type X zeolite, type Y zeolite, stabilized type Y zeolite, etc., and stabilized type Y zeolite is preferred.

[0046] <Flow Catalytic Cracking Treatment> In this embodiment, the fluid catalytic cracking treatment can be carried out by methods known in the art. The fluid catalytic cracking treatment can be carried out in an FCC apparatus by bringing the feed oil 2 into contact with the FCC catalyst.

[0047] Raw material oil 2 may consist solely of raw material oil 1, or it may be raw material oil containing raw material oil 1 and other fractions. Examples of the aforementioned other fractions include fractions obtained by directly desulfurizing either atmospheric pressure residue oil or vacuum residue oil obtained by vacuum distillation of atmospheric pressure residue oil in a vacuum distillation unit, or fractions obtained by desulfurizing coker cracking fraction obtained by thermal decomposition of the vacuum residue oil in a heavy oil thermal cracking unit.

[0048] The properties of the other fractions mentioned above are preferably as follows. The boiling point range of the raw material oil 2 is preferably 200 to 600°C, more preferably 220 to 580°C, and even more preferably 250 to 550°C. The 10% volume distillation temperature of the raw material oil 2 is preferably 300-400°C, more preferably 320-380°C, and even more preferably 340-360°C. The 50% volume distillation temperature of the raw material oil 2 is preferably 400-500°C, more preferably 420-480°C, and even more preferably 440-460°C. The 90% volume distillation temperature of the raw material oil 2 is preferably 480-580°C, more preferably 490-560°C, and even more preferably 510-540°C. The sulfur content of the raw material oil 2 relative to the total mass is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and even more preferably 0.1 to 0.3% by mass.

[0049] The fluid catalytic cracking treatment of the feed oil 2 can be carried out by continuously circulating an FCC catalyst through an FCC apparatus 1 consisting of a vertically mounted riser 10, a reaction tower 20, and a regeneration tower 30. In this specification, the fluid catalytic cracking apparatus (FCC apparatus) also includes a residual oil fluid catalytic cracking apparatus (RFCC apparatus). That is, in this specification, the fluid catalytic cracking treatment also includes the residual oil fluid catalytic cracking treatment.

[0050] The following will provide a detailed explanation of the fluid catalytic cracking process performed by the FCC apparatus. A lifting fluid flows upward within the riser 10, and the FCC catalyst supplied from the regenerating catalyst transfer line 34 flows upward within the riser 10 together with the lifting fluid. The raw material oil 2 is heated to a predetermined temperature by the preheating device 12, steam is added to it, and then it is supplied from the raw material oil supply line 11 to the riser 10. The raw material oil 2 supplied to the riser 10 comes into contact with the FCC catalyst and a decomposition reaction occurs. The decomposed oil and FCC catalyst produced by the decomposition reaction are transferred to the reaction tower 20.

[0051] The operating conditions for the riser 10 are preferably a reaction temperature of 490 to 530°C, and more preferably 500 to 520°C. When the reaction temperature is above the lower limit of the range, the decomposition reaction of the feedstock oil 2 proceeds more easily, and the conversion rate of the feedstock oil 2 improves. When the reaction temperature is below the upper limit of the range, the amount of light gases such as dry gas and coke produced by thermal decomposition can be reduced, making it easier to relatively increase the yield of the target gasoline, petrochemical raw materials, etc., and thus economical.

[0052] The reaction pressure is 0.10 MPa (atmospheric pressure) to 0.49 MPa (5 kg / cm²). 2 Preferably, the pressure is 0.10 MPa (normal pressure) to 0.29 MPa (3 kg / cm²). 2 It is more preferable that the reaction is as follows: Since the decomposition reaction is a reaction in which the number of moles of product increases relative to the number of moles of reactants, it is thermodynamically (equilibrium-wise) favorable if the reaction pressure in riser 10 is 0.49 MPa or less.

[0053] The mass ratio of FCC catalyst to raw material oil 2 is preferably 6 to 12, and more preferably 7 to 11. When the mass ratio is above the lower limit of the range, the catalyst concentration in the riser 10 can be kept at an appropriate level, and the decomposition efficiency of the raw material oil is improved. When the mass ratio is below the upper limit of the range, the decomposition reaction of the raw material oil proceeds effectively, and it becomes easier to promote a decomposition reaction that is commensurate with the increase in catalyst concentration.

[0054] The cracked oil produced by the decomposition of the feedstock oil 2 in the riser 10 is supplied to the cyclone 21. The cyclone 21 uses centrifugal force to separate the cracked oil from the FCC catalyst. The cracked oil is then discharged from the reaction tower 20 via the cracked oil discharge line 22 and transferred to the refining facility.

[0055] The FCC catalyst separated by cyclone 21 is supplied to stripper 23. Steam, nitrogen, etc. are supplied to stripper 23. In stripper 23, hydrocarbons on the FCC catalyst are removed using steam, nitrogen, etc. The FCC catalyst is then discharged from reaction tower 20 via post-reaction catalyst transfer line 24 and transferred to regeneration tower 30.

[0056] The temperature during the stripping process in the stripper 23 is typically 470 to 530°C, preferably 480 to 520°C, and more preferably 490 to 510°C. The gas used for stripping is an inert gas such as steam generated by a boiler or nitrogen pressurized by a compressor.

[0057] Air is supplied from the air blower 31 to the air grid 32, and from the air grid 32 to the regeneration tower 30. The coke on the FCC catalyst after stripping, which has been transferred to the regeneration tower 30, is burned, and the FCC catalyst is regenerated. The regenerated FCC catalyst and the exhaust gas generated by the combustion of the coke are separated by the cyclone 33. The regenerated FCC catalyst is discharged from the regeneration tower 30 via the regeneration catalyst transfer line 34 and supplied to the riser 10. The exhaust gas is discharged from the regeneration tower 30 via the exhaust gas line 35.

[0058] The operating conditions for the catalyst regeneration tower are preferably such that the regeneration temperature is 600 to 800°C, and more preferably 700 to 750°C. When the regeneration temperature in the catalyst regeneration tower is 600°C or higher, the combustion of coke proceeds sufficiently, and the catalyst activity is fully restored. Conversely, when the regeneration temperature in the catalyst regeneration tower is 800°C or lower, the adverse effects on the equipment materials are minimal.

[0059] The cracked oil, transferred from the reaction tower 20 to the refining facility via the cracked oil discharge line 22, is then distilled in the refining facility (distillation column). From the top of the column, a fraction containing compounds with 1 to 13 carbon atoms is distilled off; from the middle of the column, heavy cracked gas oil (HCO) and light cracked gas oil (LCO) are distilled off; and from the bottom of the column, fluid catalytic cracking residue (SLO) is distilled off. [Examples]

[0060] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0061] <Method for measuring distillation properties> The distillation properties of each fraction used in Examples 1-4, Comparative Examples 1-4, and Reference Examples 1-6 were measured in accordance with JIS K2254 (2018) "Petroleum Products - Method for Determining Distillation Properties".

[0062] <Distillates used in the preparation of feedstock oil for fluid catalytic cracking> The fractions used in the production of the feedstock oils for fluid catalytic cracking used in Examples 1-4, Comparative Examples 1-4, and Reference Examples 1-6 are as follows. The distillation properties of each fraction are shown in Table 1. • Reduced pressure diesel fuel (hereinafter also referred to as "VGO," including the description in Table 1). • Straight-run diesel fuel with a 10% volume distillation temperature of 330°C or higher (hereinafter also referred to as "LGO(330+)" as described in Table 1). • Light vacuum diesel fuel (hereinafter also referred to as "LVGO," including the description in Table 1).

[0063] <Indirect desulfurization treatment> The process was carried out by supplying feedstock oil to an indirect desulfurization unit equipped with an indirect desulfurization catalyst in which molybdenum and cobalt were supported on alumina. Specifically, a mixed fluid of feedstock oil heated to the reaction temperature and hydrogen-containing gas was introduced from the top of the indirect desulfurization unit, and the hydrogenation reaction of the desulfurization and decomposition reactions was carried out under the following conditions. The mixed fluid of the product oil and gas was discharged from the bottom of the reactor, and the product oil was separated by a gas-liquid separator. The product oil was then distilled at atmospheric pressure in an atmospheric distillation unit, and light vacuum gas oil was obtained from the top of the column and vacuum gas oil from the bottom of the column. The reaction conditions were: pressure (hydrogen partial pressure); 5.7 MPa, liquid space velocity; 0.511 hr -1 The hydrogen / raw material oil ratio was 1621 scf / bbl, and the reaction temperature was set so that the sulfur content in the resulting oil was 0.08% by mass.

[0064] <Flow Catalytic Cracking Treatment> FCC equilibrium catalysts containing stabilized Y-type zeolite as the active ingredient, obtained by long-term reaction in an actual fluid catalytic cracking apparatus, were loaded into a boiling bed micro-activity test apparatus (ACE-Model R+, manufactured by KAYSER TECHNOLOGY). Fluid catalytic cracking treatment was performed using the raw material oils of Examples 1-4, Comparative Examples 1-4, and Reference Examples 1-6 described below, at a reaction temperature of 510°C and an FCC catalyst regeneration temperature of 650°C. The obtained cracked oil was analyzed by gas chromatography distillation using an AC Simdis Analyzer from Agilent Technologies, and the yields of Dry Gas (H2, C1, C2 compounds), LPG (C3, C4 compounds), gasoline (boiling point 27-190°C), LCO and HCO (boiling point greater than 190°C and less than 350°C), and SLO (boiling point greater than 350°C) were analyzed. The yield of Coke was analyzed and calculated from the CO and CO2 concentrations in the regeneration column. Furthermore, the yields of H2 (H2 in Tables 2, 3A, and 3B), C1 compounds (C1 in Tables 2, 3A, and 3B), C2 compounds (C2 in Tables 2, 3A, and 3B) in Dry Gas, and C3 compounds (Total C3 in Tables 2, 3A, and 3B), and C4 compounds (Total C4 in Tables 2, 3A, and 3B) in LPG were quantified by gas chromatography. The conversion rate was calculated from 100% - the yield (mass%) of LCO and HCO - the yield (mass%) of SLO.

[0065] [Reference example 1] VGO was indirectly desulfurized to produce desulfurized vacuum gas oil (hereinafter also referred to as "T-VGO1") and desulfurized light vacuum gas oil (hereinafter also referred to as "HDS-LGO1"). T-VGO1 was used as the feedstock, and fluid catalytic cracking was performed with a mass ratio of FCC catalyst / feedstock oil of 9. The conversion rate and yield of each component are shown in Table 2.

[0066] [Example 1] Mixed oil 2 was obtained by mixing VGO and LGO(330+). For LGO(330+), the ratio of the total volume of the fraction distilled at 350°C or higher to the total volume of the fraction distilled at 350°C or lower was 1.78. The mixing ratio was 75% by volume of VGO and 25% by volume of LGO(330+). Mixed oil 2 was indirectly desulfurized to produce desulfurized vacuum gas oil (hereinafter also referred to as "T-VGO2") and desulfurized light vacuum gas oil (hereinafter also referred to as "HDS-LGO2"). Mixed oil 2' was obtained by mixing T-VGO2 and HDS-LGO2. The mixing ratio was 75% by volume of T-VGO2 and 25% by volume of HDS-LGO2. This mixed oil 2' was used as the feedstock oil, and fluid catalytic cracking treatment was performed with an FCC catalyst / feedstock oil mass ratio of 9. The conversion rate and the yield of each component are shown in Table 2.

[0067] [Example 2] Mixed oil 3 was obtained by mixing VGO and LGO(330+). The mixing ratio was 50% by volume of VGO and 50% by volume of LGO(330+). For LGO(330+), the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower was 1.78. Mixed oil 3 was indirectly desulfurized to produce desulfurized vacuum gas oil (hereinafter also referred to as "T-VGO3") and desulfurized light vacuum gas oil (hereinafter also referred to as "HDS-LGO3"). Mixed oil 3' was obtained by mixing T-VGO3 and HDS-LGO3. The mixing ratio was 68% by volume of T-VGO3 and 32% by volume of HDS-LGO3. This mixed oil 3' was used as the feedstock oil, and fluid catalytic cracking treatment was performed with an FCC catalyst / feedstock oil mass ratio of 9. The conversion rate and the yield of each component are shown in Table 2.

[0068] [Reference example 2] Mixed oil 4 was obtained by mixing T-VGO1 and HDS-LGO1 in Reference Example 1. The mixing ratio was 75% by volume of T-VGO1 and 25% by volume of HDS-LGO1. This mixed oil 4 was used as the feedstock oil, and fluid catalytic cracking treatment was performed with a mass ratio of FCC catalyst / feedstock oil of 9. The conversion rate and the yield of each component are shown in Table 2. The distillation properties of HDS-LGO1 are shown in Table 1.

[0069] [Reference example 3] Mixed oil 5 was obtained by mixing T-VGO1 and HDS-LGO1 in Reference Example 1. The mixing ratio was 50% by volume of T-VGO1 and 50% by volume of HDS-LGO1. This mixed oil 5 was used as the feedstock oil, and fluid catalytic cracking treatment was performed with a mass ratio of FCC catalyst / feedstock oil of 9. The conversion rate and the yield of each component are shown in Table 2.

[0070] [Comparative Example 1] Mixed oil 6 was obtained by mixing VGO and LVGO. The mixing ratio was 75% by volume of VGO and 25% by volume of LVGO. For LVGO, the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower was 0.09. Mixed oil 6 was indirectly desulfurized to produce desulfurized vacuum gas oil (hereinafter also referred to as "T-VGO4") and desulfurized light vacuum gas oil (hereinafter also referred to as "HDS-LGO4"). Mixed oil 6' was obtained by mixing T-VGO4 and HDS-LGO4. The mixing ratio was 66% by volume of T-VGO4 and 34% by volume of HDS-LGO4. This mixed oil 6' was used as the feedstock oil, and fluid catalytic cracking treatment was performed with an FCC catalyst / feedstock oil mass ratio of 9. The conversion rate and the yield of each component are shown in Table 2.

[0071] [Comparative Example 2] Mixed oil 7 was obtained by mixing VGO and LVGO. The mixing ratio was 50% by volume of VGO and 50% by volume of LVGO. For LVGO, the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower was 0.09. Mixed oil 7 was subjected to indirect desulfurization treatment to produce desulfurized vacuum gas oil (hereinafter also referred to as "T-VGO5") and desulfurized light vacuum gas oil (hereinafter also referred to as "HDS-LGO5"). Mixed oil 7' was obtained by mixing T-VGO5 and HDS-LGO5. The mixing ratio was 50% by volume of T-VGO5 and 50% by volume of HDS-LGO5. This mixed oil 7' was used as the feedstock oil, and fluid catalytic cracking treatment was performed with an FCC catalyst / feedstock oil mass ratio of 9. The conversion rate and the yield of each component are shown in Table 2.

[0072] [Table 1]

[0073] [Table 2]

[0074] In Examples 1 and 2, the conversion rate was higher and the gasoline yield was higher than in Reference Examples 1 to 3, which used conventional feedstock oil obtained by hydrogenating only VGO. On the other hand, in Comparative Examples 1 and 2, the conversion rate was lower than in Reference Examples 1 to 3, which used conventional feedstock oil obtained by hydrogenating only VGO.

[0075] [Reference example 4] Similar to Reference Example 1, T-VGO1 was used as the feedstock, and the mass ratio of the FCC catalyst to the feedstock was changed as shown in Table 3A, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3A.

[0076] [Example 3] Similar to Example 1, mixed oil 2' was used as the feedstock oil, and the mass ratio of FCC catalyst / feedstock oil was changed as shown in Table 3A before performing fluid catalytic cracking. The conversion rate and the yield of each component are shown in Table 3A.

[0077] [Example 4] Similar to Example 2, mixed oil 3' was used as the feedstock oil, and the mass ratio of the FCC catalyst to the feedstock oil was changed as shown in Table 3A, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3A.

[0078] [Reference example 5] Similar to Reference Example 2, mixed oil 4 was used as the raw material, and the mass ratio of the FCC catalyst to the raw material was changed as shown in Table 3B, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3B.

[0079] [Reference example 6] Similar to Reference Example 3, mixed oil 5 was used as the raw material, and the mass ratio of the FCC catalyst to the raw material was changed as shown in Table 3B, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3B.

[0080] [Comparative Example 3] Similar to Comparative Example 1, mixed oil 6' was used as the feedstock oil, and the mass ratio of the FCC catalyst to the feedstock oil was changed as shown in Table 3B, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3B.

[0081] [Comparative Example 3] Similar to Comparative Example 2, mixed oil 7' was used as the feedstock oil, and the mass ratio of the FCC catalyst to the feedstock oil was changed as shown in Table 3B, and fluid catalytic cracking treatment was performed. The conversion rate and the yield of each component are shown in Table 3B.

[0082] [Table 3A]

[0083] [Table 3B]

[0084] In equivalent FCC catalyst / raw material oil mass ratios, Examples 3 and 4 showed higher conversion rates and higher gasoline yields than Reference Examples 4-6, which used conventional raw material oil obtained by hydrogenating only VGO. On the other hand, in equivalent FCC catalyst / raw material oil mass ratios, Comparative Examples 3 and 4 showed lower conversion rates than Reference Examples 4-6, which used conventional raw material oil obtained by hydrogenating only VGO. [Industrial applicability]

[0085] Using the feedstock oil for fluid catalytic cracking according to the present invention is useful because it results in a conversion rate equal to or higher than that when only desulfurized vacuum gas oil is used as the feedstock oil for fluid catalytic cracking. In other words, when the amount of vacuum gas oil (i.e., desulfurized vacuum gas oil) is insufficient compared to the maximum processing capacity set in the fluid catalytic cracking apparatus, using the feedstock oil for fluid catalytic cracking according to the present invention can increase the operating rate of the fluid catalytic cracking apparatus and improve profitability. [Explanation of Symbols]

[0086] 1…Fluid catalytic cracking unit, 10…Riser, 11…Food oil supply line, 12…Preheating unit, 20…Reaction tower, 21…Cyclone, 22…Cracked oil discharge line, 23…Stripper, 24…Post-reaction catalyst transfer line, 30…Regeneration tower, 31…Air blower, 32…Air grid, 33…Cyclone, 34…Regenerated catalyst transfer line, 35…Exhaust gas line, 100…Atmospheric distillation unit, 200…Reduced pressure distillation unit, 300…Indirect desulfurization unit

Claims

1. A method for producing a raw material oil for fluid catalytic cracking, 1 to 60 volume percent of fraction A, in which the ratio of the total volume of fractions distilled at 350°C or higher to the total volume of fractions distilled at 350°C or lower is 0.3 or higher, A fraction consisting of 40-99% by volume of vacuum diesel fuel is subjected to hydrogenation treatment. This process involves mixing the heavy fraction of the obtained fraction, which is desulfurized vacuum gas oil, with the light fraction, which is desulfurized light vacuum gas oil. A method for producing a raw material for fluid catalytic cracking, wherein the content of the desulfurized vacuum gas oil relative to the total volume of the raw material for fluid catalytic cracking is 30 to 80% by volume, and the content of the desulfurized light vacuum gas oil is 10 to 50% by volume.

2. The method for producing a fluid catalytic cracking raw material oil according to claim 1, wherein the content of the fraction distilled at 340 to 400°C relative to the total volume of the fluid catalytic cracking raw material oil is 20 to 50% by volume.

3. The method for producing a feedstock for fluid catalytic cracking according to claim 1 or 2, wherein the fraction A includes a fraction B containing a straight-run gas oil fraction obtained by atmospheric distillation of crude oil, and the content of the straight-run gas oil fraction relative to the total volume of fraction B is 80 to 100% by volume.

4. The method for producing a raw material for fluid catalytic cracking according to claim 1 or 2, wherein the boiling point range of the desulfurized vacuum gas oil is 200 to 600°C, and the boiling point range of the desulfurized light vacuum gas oil is 160 to 370°C.

5. A raw material for fluid catalytic cracking is obtained by the method for producing a raw material for fluid catalytic cracking described in claim 1 or 2. A fluid catalytic cracking method comprising processing a raw material oil containing the aforementioned raw material oil for fluid catalytic cracking in a fluid catalytic cracking apparatus.

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