JP2016155960A - Fluid catalytic cracking apparatus and catalytic cracking method of stock oil using the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FCC apparatus that can produce a cracked product capable of increasing a yield of gasoline and to provide a catalytic cracking method of a stock oil using the FCC apparatus.SOLUTION: A fluid catalytic cracking apparatus 1 comprises a riser 10 for producing a cracked product by bringing a stock oil into contact with a catalyst to crack the stock oil, a reaction tower 20 for separating the cracked product and the catalyst and a regeneration tower 30 for regenerating the catalyst by burning coke present on the separated catalyst. The catalyst with which the stock oil is brought into contact in the riser 10 includes a catalyst regenerated by the regeneration tower 30 and the ratio of the catalyst having a particle size of 50 μm or less in the catalyst with which the stock oil is brought into contact is 10 mass% or more. The catalytic cracking method of the stock oil uses the fluid catalytic cracking apparatus 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluid catalytic cracking apparatus for cracking raw material oil by bringing the raw material oil into contact with a catalyst and a method for catalytic cracking of raw material oil using the apparatus.

  A fluid catalytic cracking apparatus (FCC apparatus) including a reaction tower and a regeneration tower is known as a prior art (see, for example, Patent Document 1). In the FCC device, the feedstock oil is brought into contact with the catalyst to decompose the feedstock oil, the cracked product and the catalyst are separated in the reaction tower, the separated catalyst is transferred to the regeneration tower, and the coke on the catalyst in the regeneration tower. To regenerate the catalyst, and the regenerated catalyst is used again for the decomposition of the feedstock.

  As a catalyst used in the FCC apparatus, 10 to 75% by mass of clay mineral, 20 to 60% by mass of crystalline aluminosilicate, 5 to 40% by mass of alumina binder, and the average particle of the clay mineral A hydrocarbon oil catalytic cracking catalyst having a diameter of 1 μm or less and a 90% by mass particle diameter of 2 μm or less is known as a prior art (see, for example, Patent Document 2). By using this catalytic cracking catalyst, FCC gasoline can be obtained in high yield.

JP-A-11-102204 JP 2008-173583 A

  Fluid catalytic cracking by an FCC device is often performed for the purpose of obtaining gasoline. For this reason, in the FCC apparatus, it is desirable that the yield of gasoline distilled from the decomposition product is high. Then, an object of this invention is to provide the FCC apparatus which can obtain the cracked product which can make the yield of gasoline high, and the catalytic cracking method of feedstock using the FCC apparatus.

In the catalyst circulating between the reaction tower and the regeneration tower in the FCC unit, some of the particles having a particle size of 50 μm or less have been treated with the decomposition products or the exhaust gas when coke is burned so far. And was discharged from the FCC unit. However, the present inventors have found that a decomposition product capable of increasing the yield of gasoline can be obtained by setting the ratio of the catalyst having a particle size of 50 μm or less to a predetermined value or more, and completed the present invention. I let you. That is, the present invention is as follows.
[1] Bringing a raw material oil into contact with a catalyst to decompose the raw material oil to generate a decomposition product, a reaction tower for separating the decomposition product and the catalyst, and burning coke on the separated catalyst The catalyst that regenerates the catalyst by the catalyst and is brought into contact with the raw material oil in the riser includes the catalyst regenerated by the regenerating tower, and the ratio of the catalyst having a particle diameter of 50 μm or less in the catalyst that is brought into contact with the raw material oil is 10% by mass This is the fluid catalytic cracking apparatus.
[2] The fluid catalytic cracking apparatus according to the above [1], wherein the ratio of the catalyst having a particle size of 50 μm or less in the catalyst brought into contact with the raw material oil is 10% by mass or more and 20% by mass or less.
[3] The catalyst contains at least one zeolite selected from the group consisting of Y-type zeolite, ultra-stable Y-type zeolite, β-zeolite and ZSM-5-type zeolite, and the proportion of the zeolite in the catalyst is 10 mass. The fluid catalytic cracking apparatus according to the above [1] or [2], which is not less than 40% and not more than 40% by mass.
[4] The catalyst contains at least one selected from the group consisting of alumina, clay minerals, and silica, the proportion of alumina in the catalyst is 60% by mass or less, and the proportion of clay mineral in the catalyst is 80% by mass or less. The fluid catalytic cracking apparatus according to any one of [1] to [3], wherein the ratio of silica in the catalyst is 60% by mass or less.
[5] The density of the raw material oil is 0.88 g / cm ³ or more and 0.95 g / cm ³ or less, the residual carbon content of the raw material oil is 0.5 mass% or more and 7.0 mass% or less, Fluidized catalytic cracking apparatus as described in any one of said [1]-[4] whose sulfur content is 0.1 to 0.7 mass%.
[6] Any one of the above [1] to [5], wherein the outlet temperature of the reaction tower is 450 ° C. or higher and 550 ° C. or lower, and the mass ratio of the catalyst to the raw material oil (catalyst / raw material oil) is 5 or more and 20 or less. Fluidized catalytic cracking apparatus as described in one.
[7] A method for catalytic cracking of raw oil using the fluid catalytic cracking apparatus according to any one of [1] to [6].

  ADVANTAGE OF THE INVENTION According to this invention, the FCC apparatus which can obtain the decomposition product which can make the yield of gasoline high, and the catalytic cracking method of feedstock using the FCC apparatus can be provided.

FIG. 1 is a schematic configuration diagram showing an FCC apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view for explaining distillation of a decomposition product obtained by the FCC apparatus according to one embodiment of the present invention.

[FCC equipment]
With reference to FIG. 1, the FCC apparatus in one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram showing an FCC apparatus according to an embodiment of the present invention. The FCC apparatus 1 includes a riser 10, a reaction tower 20, and a regeneration tower 30.

(Riser)
The riser 10 generates a decomposition product by bringing the raw material oil into contact with the catalyst to decompose the raw material oil. The riser 10 is connected to, for example, a regenerated catalyst transfer line 34 that supplies the catalyst regenerated in the regeneration tower 30 and a raw material oil supply line 11 that supplies raw material oil. In the riser 10, the lifting fluid A flows, and the catalyst supplied from the regenerated catalyst transfer line 34 flows in the riser 10 together with the lifting fluid A. The raw material oil B is heated by the preheating device 12 and added with steam C, and then supplied to the riser 10 from the raw material oil supply line 11. The feedstock supplied into the riser 10 comes into contact with the catalyst and decomposes. The decomposition product and catalyst produced by the decomposition of the raw material oil are transferred to the reaction tower 20.

(catalyst)
The catalyst brought into contact with the raw material oil B in the riser 10 includes a catalyst regenerated by the regeneration tower 30. The catalyst that is brought into contact with the raw material oil B in the riser 10 may be a catalyst regenerated by the regeneration tower 30. Further, a part of the catalyst brought into contact with the raw material oil B in the riser 10 may be a new catalyst. Normally, a part of the catalyst circulating in the FCC apparatus is extracted from the FCC apparatus 1 and a new catalyst is supplied to the FCC apparatus 1 in order to keep the activity of the catalyst constant. In this way, a catalyst in which the activity of the catalyst is maintained constant is generally called an equilibrium catalyst.

  The ratio of the catalyst having a particle size of 50 μm or less in the catalyst brought into contact with the raw material oil B is 10% by mass or more, and preferably 10% by mass or more and 20% by mass or less. When the ratio of the catalyst having a particle size of 50 μm or less in the catalyst brought into contact with the raw material oil B is less than 10% by mass, the yield of gasoline in the cracked product obtained by the FCC apparatus 1 becomes low.

  From the viewpoint of wear resistance, hydrothermal resistance and metal poisoning resistance, the catalyst to be contacted with the feedstock B is preferably selected from the group consisting of Y-type zeolite, ultra-stable Y-type zeolite, β-zeolite and ZSM-5-type zeolite. At least one zeolite. The proportion of the zeolite in the catalyst is preferably 10% by mass to 40% by mass, preferably 15% by mass to 40% by mass, and more preferably 15% by mass to 35% by mass. Further, the catalyst brought into contact with the raw material oil B may contain at least one selected from the group consisting of alumina, clay minerals and silica. In this case, for example, the proportion of alumina in the catalyst is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 45% by mass or less. Moreover, the ratio of the clay mineral in a catalyst becomes like this. Preferably it is 80 mass% or less, More preferably, it is 75 mass% or less, More preferably, it is 70 mass% or less. Further, the ratio of silica in the catalyst is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 45% by mass or less.

(Raw oil)
From the viewpoint of increasing the yield of gasoline in the cracked product obtained by the FCC apparatus 1 in one embodiment of the present invention, the density of the feedstock B used in the FCC apparatus 1 in one embodiment of the present invention is preferably Is 0.88 g / cm ³ or more and 0.95 g / cm ³ or less, more preferably 0.89 / cm ³ or more and 0.94 g / cm ³ or less, and further preferably 0.90 / cm ³ or more and 0.00. 94 g / cm ³ or less. The residual carbon content of the feedstock is preferably 0.5% by mass or more and 7.0% by mass or less, more preferably 6.0% by mass or less, and further preferably 5.0% by mass or less. . Further, the sulfur content of the raw material oil is preferably 0.1% by mass or more and 0.7% by mass or less, more preferably 0.1% by mass or more and 0.6% by mass or less, and further preferably 0.1% by mass. % Or more and 0.5% by mass or less.

  The raw material oil B processed by the FCC apparatus 1 in one embodiment of the present invention is, for example, heavy oil. Fluid catalytic cracking of heavy oil is commonly referred to as residual fluid catalytic cracking (RFCC). In order to remove impurities that adversely affect the operation of the FCC apparatus, and because the aromatic rings in the feedstock are easily hydrogenated and decomposed, the heavy processed by the FCC apparatus 1 in one embodiment of the present invention The oil is preferably hydrodesulfurized and hydrocracked in advance. Examples of such heavy oil include indirect desulfurized heavy oil and direct desulfurized heavy oil. Indirect desulfurized heavy oil includes, for example, desulfurized vacuum gas oil (VHHGO) obtained by desulfurizing heavy gas oil and vacuum gas oil obtained by atmospheric distillation of crude oil with an indirect desulfurizer (VH). Indirect desulfurized heavy oil and degassed oil (DAO) obtained from a solvent degassing apparatus may be used together as a raw material oil. On the other hand, for direct desulfurized heavy oil, high-density petroleum such as crude oil atmospheric distillation residue (AR) and vacuum distillation residue (VR), heavy gas oil, catalytic cracking residue, visbreaking oil and bitumen, for example. Examples thereof include desulfurized heavy oil (DSAR) obtained by hydrodesulfurizing and hydrocracking a fraction in a heavy oil direct desulfurization unit (RH).

Hydrodesulfurization and hydrocracking to obtain desulfurized heavy oil (DSAR) are performed in the presence of a catalyst. And, by optimizing reaction conditions such as reaction temperature, reaction pressure and liquid space velocity, it is possible to achieve the desulfurization rate and heavy oil decomposition rate required to obtain desulfurized heavy oil (DSAR). . Hydrodesulfurization and hydrocracking are usually 300 ° C. or higher and 450 ° C. or lower, preferably 330 ° C. or higher and 420 ° C. or lower, more preferably 380 ° C. or higher and 420 ° C. or lower, and usually 10 MPa or higher and 22 MPa or lower, preferably 13 MPa. It is carried out under a hydrogen pressure of 20 MPa or less. Liquid hourly space velocity of the hydrodesulfurization and hydrocracking (LHSV) is usually 0.1 h ^-1 or ^{10h -1} or less, preferably 0.1 h ^-1 or more ^{3h -1} or less, the hydrogen to oil ratio (hydrogen / oil) is usually 200 Nm ³ / KL than 10,000 nM ³ / KL or less, preferably 500 Nm ³ / KL than 10,000 nM ³ / KL.

  The hydrodesulfurization and hydrocracking to obtain desulfurized heavy oil (DSAR) preferably includes two steps of a hydrodesulfurization treatment step as a first step and a hydrodesulfurization treatment step as a second step. The raw heavy oil is first hydrodemetallized in the hydrodemetallation process, which is the first step, and metal components such as vanadium and nickel that cause a decrease in the activity of the hydrodesulfurization catalyst are hydrogenated. The heavy metal oil is demetalized. Next, the raw material heavy oil treated in the hydrodemetallation process is sent to the hydrodesulfurization process, which is the second process, and the hydrodesulfurization process is performed. The first step and the second step may be performed in the same apparatus or may be performed in separate apparatuses. From the viewpoint of suppressing the deterioration of the catalyst, it is preferable to separately provide a demetallizer such as an OCR (On Stream Catalyst Replacement) device upstream of the heavy oil direct desulfurizer (RH).

  As a specific means for realizing the function sharing between the first step and the second step, the pore structure of the catalyst support and the amount of the supported metal are used as parameters. For example, in the first step, the pore size of the support is increased ( Alternatively, by increasing the pore volume of the catalyst by capturing a large amount of metal in the molecule, the surface area is large in the second step (the pore diameter is small and the number is large). You may mainly hydrodesulfurize a sulfur compound using the catalyst which supported the active metal more on the support | carrier. Each of these steps has the main function sharing as described above, but as a whole, hydrorefining treatment of raw material heavy oil is performed.

  As a catalyst used for hydrodesulfurization and hydrocracking to obtain desulfurized heavy oil (DSAR), any of known catalysts having hydrodemetallization ability and hydrodesulfurization ability can be used. Examples of such a catalyst include a catalyst in which a group V to VIII metal, or a sulfide or oxide thereof is supported on a support selected from the group consisting of alumina, silica-alumina, zeolite, and a mixture thereof. Is mentioned. From the viewpoint of using an active metal suitable for hydrodesulfurization, the metal of the group V to VIII metal is preferably nickel, cobalt, molybdenum, tungsten, or a combination thereof. From the viewpoint of superior hydrodesulfurization, hydrocracking and hydrogenation ability with respect to heavy oil, the catalyst used for hydrodesulfurization and hydrocracking to obtain desulfurized heavy oil (DSAR) is more preferably , A catalyst in which a metal such as Co—Mo, Co—Mo—P, Ni—Mo and Ni—Mo—P is supported on a porous inorganic oxide carrier such as alumina.

  As the reactor used in the hydrodesulfurization and hydrocracking, a conventionally known type of reactor can be used. The reactor used in the hydrodesulfurization and hydrocracking may be either a fixed bed or a moving bed, and may be either a downflow type or an upflow type.

  The reaction product obtained by hydrodesulfurization and hydrocracking in the heavy oil direct desulfurization unit (RH) is separated into gas and liquid by a gas-liquid separator, and the liquid phase is separated by naphtha fraction, kerosene fraction by separation operation such as distillation. Fractions, light oil fractions, heavy oil fractions, etc. Desulfurized heavy oil (DSAR), which is the heavy oil fraction obtained at this time, is used as the FCC feedstock.

  In hydrodesulfurization and hydrocracking in the heavy oil direct desulfurization unit (RH), the desulfurization rate (HDS), denitrogenation rate (HDN), devanadium rate (HDV), denicking rate (HDNi), decarburized carbon It is preferable that the rate (HDCR) and the deasphalten rate (HDAs) are 80 to 90%, 35 to 40%, 75 to 80%, 65 to 75%, 50 to 55%, and 60% or more, respectively. These are all calculated as the removal ratio of each component from the amount of each component in the raw oil and product oil of the heavy oil direct desulfurization unit (RH).

  In the heavy oil processed by the FCC apparatus 1 in one embodiment of the present invention, heavy gas oil (HGO), vacuum gas oil (VGO) is used as long as the effects of the present invention are not impaired compared to the above heavy oil. ), Degassed diesel oil (DAO), atmospheric residual oil (AR) and the like can be used in combination.

  The mass ratio of the catalyst to the raw material oil B (catalyst / raw material oil) is preferably 5 or more and 20 or less, more preferably 5.5 or more and 18 or less, and further preferably 6 or more and 15 or less. When the mass ratio of the catalyst to the raw material oil B (catalyst / raw material oil) is 5 or more and 20 or less, the raw material oil B can be sufficiently brought into contact with the catalyst and the throughput of the raw material oil can be increased.

(Reaction tower)
The reaction tower 20 separates the decomposition product E and the catalyst. The reaction tower 20 includes, for example, a cyclone 21, a decomposition product discharge line 22, a stripper 23, and a spent catalyst transfer line 24. The decomposition product E generated by the decomposition of the raw material oil in the riser 10 is supplied to the cyclone 21. The cyclone 21 uses the centrifugal force to separate the decomposition product E from the catalyst. And the decomposition product E is discharged | emitted from the reaction tower 20 by the decomposition product discharge line 22, and is transferred to the following process. In the FCC apparatus 1 according to one embodiment of the present invention, the operating conditions of the cyclone 21 are adjusted so that the catalyst having a particle size of 50 μm or less is not discharged from the reaction tower 20 together with the decomposition products as much as possible. The catalyst separated by the cyclone 21 is supplied to the stripper 23. Steam is supplied to the stripper 23. In the stripper 23, hydrocarbons on the catalyst are removed by steam, and the amount of coke on the catalyst is reduced. Then, the catalyst is discharged from the reaction tower 20 through the spent catalyst transfer line 24 and transferred to the regeneration tower 30.

  The outlet temperature of the reaction tower 20 is preferably 450 ° C. or higher and 550 ° C. or lower, more preferably 470 ° C. or higher and 540 ° C. or lower, and further preferably 490 ° C. or higher and 530 ° C. or lower. When the outlet temperature of the reaction tower 20 is 450 ° C. or more and 550 ° C. or less, non-evaporated hydrocarbons on the catalyst increase and decrease, and the amount of hydrocarbons brought into the regeneration tower 30 can be further reduced.

(Regeneration tower)
The regeneration tower 30 regenerates the catalyst by burning the coke on the 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 regeneration catalyst transfer line 34, and an exhaust gas line 35. Air F is supplied from the air blower 31 to the air grid 32, and air is supplied from the air grid 32 into the regeneration tower 30. The spent catalyst is supplied to the regeneration tower 30 from the spent catalyst transfer line 24. When air is supplied into the regeneration tower 30, the coke on the catalyst burns and the catalyst is regenerated. In the regeneration tower 30, for example, a used catalyst is regenerated at a temperature of 640 to 800 ° C. The regenerated catalyst and the exhaust gas generated by the combustion of coke are separated by the cyclone 33. The regenerated catalyst is discharged from the regeneration tower 30 through the regenerated catalyst transfer line 34 and supplied to the riser 10. The exhaust gas is discharged from the regeneration tower 30 through the exhaust gas line 35. The exhaust gas contains CO ₂ gas and SOx gas as main components. In the FCC apparatus 1 according to an embodiment of the present invention, the operating conditions of the cyclone 32 are adjusted so that a catalyst having a particle size of 50 μm or less is not discharged from the regeneration tower 30 together with the exhaust gas as much as possible.

(Decomposition product)
The decomposition product E discharged from the reaction tower 20 is washed and rectified by, for example, a main distillation tower. The distillation of the decomposition product E will be described with reference to FIG. FIG. 2 is a schematic diagram for explaining distillation of the decomposition product E obtained by the FCC apparatus 1 according to one embodiment of the present invention. The cracked product E is transferred to the main distillation column 41, and fuel gas G, liquefied petroleum gas (LPG) H and gasoline I are distilled from the top of the main distillation column 41, and cracked light oil ( LCO) J is distilled, and cracked bottom oil (SLO) K is distilled from the bottom of the main distillation column 41. Further, as the reflux fraction for removing heat from the main fractionator 41, there are light naphtha circulating oil (TPA), heavy naphtha (MPA) and heavy light oil circulating oil (HPA).

  In the fuel gas G, the total ratio of the C1 fraction and the C2 fraction is preferably 40 mol% or more, and the hydrogen ratio is preferably 20 mol% or less. In addition, the ratio of C1 fraction, C2 fraction, and hydrogen is a value measured according to JIS K 2301 “Fuel gas and natural gas—analysis and test method”. Liquefied petroleum gas (LPG) H contains a C3 fraction (propane, propylene) and a C4 fraction (butane, butylene). The total proportion of propane and propylene in the C3 fraction is preferably 95 mol% or more. The total proportion of butane and butylene in the C4 fraction is preferably 95 mol% or more. The ratio of the total of propane and propylene in the C3 fraction and the ratio of the total of butane and butylene in the C4 fraction are values measured according to JIS K 2240 “Liquefied petroleum gas-composition analysis method”.

Gasoline I is a fraction having a boiling range of less than 185 ° C. The density of gasoline I at 15 ° C. is preferably 0.7200 g / cm ³ or more, and the sulfur content is preferably 100 ppm or less. Cracked gas oil (LCO) J is a fraction of 185 ° C or higher and 370 ° C or lower. The density of cracked light oil (LCO) J at 15 ° C. is preferably 0.9000 g / cm ³ or more, and the sulfur content is preferably 0.30% by mass or less. Cracked bottom oil (SLO) K is a fraction of 370 ° C or higher. The density of cracked bottom oil (SLO) K at 15 ° C. is preferably 1.1000 g / cm ³ or less, and the sulfur content is preferably 1.25% by mass or less. The density at 15 ° C. is a value measured in accordance with JIS K 2249 “Crude oil and petroleum product density test method and density / mass / capacity conversion table”, and the sulfur content is JIS K 2541 “crude oil and petroleum It is a value measured in accordance with “Petroleum product-Sulfur content test method”.

  The above description is merely an example, and the present invention is not limited to the above embodiment.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples.

[Measurement and evaluation]
The catalysts and feedstocks used in the feedstock catalytic cracking methods of Examples and Comparative Examples were measured and evaluated as follows.
(1) Particle size distribution and average particle size of the catalysts used in the examples and comparative examples The proportion of the catalyst having a particle size of 40 μm or less and the proportion of the catalyst having a particle size of 50 μm or less in the catalysts used in the examples and comparative examples, and The average particle size was measured according to JIS Z 8815 (screening test method).
(2) BET specific surface area of catalyst used in examples and comparative examples The specific surface area of the catalysts used in the examples and comparative examples was measured using a specific surface area measuring device (manufactured by Cantachrome, Inc., model number: Autosorb 3). , Measured by the BET multipoint method under conditions of a relative pressure of nitrogen of 0.3 (P / P ₀ ).
(3) Density at 15 ° C. of the feedstock oil used in Examples and Comparative Examples The density at 15 ° C of the feedstock oil conforms to JIS K 2249 “Density test method and density / mass / capacity conversion table for crude oil and petroleum products”. And measured.
(4) Residual coal of raw material oil used in Examples and Comparative Examples Residual coal of raw material oil conforms to JIS K 2270-1 "Crude oil and petroleum products-Determination of residual carbon content-Part 1: Conradson method" And measured.
(5) Sulfur content of raw material oil used in Examples and Comparative Examples The sulfur content of the raw material oil was measured according to JIS K2541 “Crude oil and petroleum products—sulfur content test method”.

[Methods for catalytic cracking of raw oils of Examples and Comparative Examples]
The catalytic cracking method of the raw material oil of Examples 1-4 and Comparative Examples 1 and 2 was implemented as follows.
(Examples 1 to 3, Comparative Example 1)
A catalyst containing 25% by mass of ultrastable Y-type zeolite, 0% by mass of alumina, 68% by mass of clay mineral, 5% by mass of silica, and 2% by mass including other impurities was used. By changing the cyclone efficiency in the regeneration tower and adjusting the catalyst discharge in the regeneration tower, the ratio of the catalyst having a particle diameter of 40 μm or less, the ratio of the catalyst having a particle diameter of 50 μm or less, and the average particle diameter of the catalyst are changed. It was. The ratio of the catalyst having a particle diameter of 40 μm or less, the ratio of the catalyst having a particle diameter of 50 μm or less, the average particle diameter and the specific surface area in the catalysts of Examples 1 to 3 and Comparative Example 1 are shown in Table 1 below. The properties of the feed oil are shown below. Furthermore, the operating conditions of the FCC device are also shown below.
Properties of the feed oil Density at 50 ° C .: 0.925 ± 0.05 g / cm ³
Residual charcoal: 3.8 ± 0.5% by mass
Sulfur content: 0.30 ± 0.03 mass%
Operating conditions of FCC unit Reaction tower outlet temperature (ROT): 518 ± 3 ° C
Mass ratio of catalyst to feedstock (catalyst / feedstock): 6.5 ± 0.3

(Example 4, Comparative Example 2)
A catalyst containing 15% by mass of ultrastable Y-type zeolite, 8% by mass of alumina, 70% by mass of clay mineral, 5% by mass of silica, and 2% by mass including other impurities was used. Other than that, the catalytic cracking method of Example 4 and Comparative Example 2 was carried out in the same manner as in the catalytic cracking method of Examples 1 to 3 and Comparative Example 1. The ratio of the catalyst having a particle diameter of 40 μm or less, the ratio of the catalyst having a particle diameter of 50 μm or less, the average particle diameter, and the specific surface area are shown in Table 2 below.

[Measurement and evaluation results]
Respective yields and total yields of fuel gas, LPG, gasoline, cracked light oil and cracked bottom oil distilled from cracked products obtained by the catalytic cracking methods of the raw material oils of Examples 1 to 3 and Comparative Example 1 Is shown in Table 3 below. In addition, the respective yields and total yields of fuel gas, LPG, gasoline, cracked gas oil and cracked bottom oil distilled from the cracked products obtained by the catalytic cracking method of the raw material oil of Example 4 and Comparative Example 2 are shown. It is shown in Table 4 below. Distillation from the cracked product obtained by the catalytic cracking method of the feedstock of Comparative Example 1 and the yield of gasoline distilled from the cracking product obtained by the cracking product of the feedstock of Examples 1-3 And the yield of gasoline distilled from the cracked product obtained by the catalytic cracking method of the feedstock of Example 4 and the feedstock of Comparative Example 2 By comparing the yield of gasoline distilled from the cracked product obtained by the catalytic cracking method, the ratio of the catalyst having a particle size of 50 μm or less in the catalyst to be brought into contact with the raw material oil is set to 10% by mass or more. It was found that a decomposition product capable of increasing the gasoline yield can be obtained.

DESCRIPTION OF SYMBOLS 1 FCC apparatus 10 Riser 11 Raw material oil supply line 20 Reaction tower 21 Cyclone 22 Decomposition product discharge line 23 Stripper 24 Spent catalyst transfer line 30 Regeneration tower 31 Air blower 32 Air grid 33 Cyclone 34 Regenerated catalyst transfer line 35 Exhaust gas line 41 Main distillation Tower

Claims (7)

A riser that generates a decomposition product by bringing the feedstock into contact with a catalyst and breaking down the feedstock;
A reaction tower for separating the decomposition product and the catalyst, and a regeneration tower for regenerating the catalyst by burning coke on the separated catalyst,
The catalyst brought into contact with the raw material oil in the riser includes the catalyst regenerated by the regeneration tower,
A fluid catalytic cracking apparatus in which a ratio of a catalyst having a particle diameter of 50 μm or less in the catalyst brought into contact with the raw material oil is 10% by mass or more.   The fluid catalytic cracking apparatus according to claim 1, wherein a ratio of a catalyst having a particle diameter of 50 µm or less in the catalyst brought into contact with the raw material oil is 10 mass% or more and 20 mass% or less. The catalyst comprises at least one zeolite selected from the group consisting of Y-type zeolite, ultra-stable Y-type zeolite, β-zeolite and ZSM-5-type zeolite;
The fluid catalytic cracking apparatus according to claim 1 or 2, wherein a ratio of the zeolite in the catalyst is 10 mass% or more and 40 mass% or less. The catalyst comprises at least one selected from the group consisting of alumina, clay minerals and silica;
A ratio of the alumina in the catalyst is 60% by mass or less;
The proportion of the clay mineral in the catalyst is 80% by mass or less,
The fluid catalytic cracking apparatus according to any one of claims 1 to 3, wherein a ratio of the silica in the catalyst is 60 mass% or less. The density of the raw material oil is 0.88 g / cm ³ or more and 0.95 g / cm ³ or less,
The residual carbon content of the raw material oil is 0.5 mass% or more and 7.0 mass% or less,
The fluid catalytic cracking apparatus according to any one of claims 1 to 4, wherein a sulfur content of the raw material oil is 0.1 mass% or more and 0.7 mass% or less. The outlet temperature of the reaction tower is 450 ° C. or higher and 550 ° C. or lower,
The fluid catalytic cracking apparatus according to any one of claims 1 to 5, wherein a mass ratio of the catalyst to the raw material oil (catalyst / raw material oil) is 5 or more and 20 or less.   A method for catalytic cracking of raw material oil using the fluid catalytic cracking apparatus according to any one of claims 1 to 6.