JP2022166720A - Method of operating fluid catalytic cracking apparatus and fluid catalytic cracking apparatus - Google Patents

Abstract

To provided a method of operating a fluid catalytic cracking apparatus that improves processing capacity of the fluid catalytic cracking apparatus while suppressing an increase in load on an air blower, and to provide the fluid catalytic cracking apparatus.SOLUTION: A fluid catalytic cracking apparatus comprises: a reaction tower for performing a reaction using a fluid catalytic cracking catalyst; and a regeneration tower for regenerating the fluid catalytic cracking catalyst used in the reaction tower, a method of operating the fluid catalytic cracking apparatus comprises regenerating the fluid catalytic cracking catalyst by supplying oxygen and air to the regeneration tower, and the apparatus comprises: the reaction tower; the regeneration tower; and supply means for supplying oxygen and air to the regeneration tower.SELECTED DRAWING: None

Description

The present invention relates to a method of operating a fluid catalytic cracking unit and a fluid catalytic cracking unit.

In recent years, the prevention of environmental pollution has been identified as one of the most important global issues. It was decided to tighten the regulations on the sulfur content from the current 3.5 mass % or less to 0.5 mass % or less. Therefore, there is an urgent need to make the fuel oil composition for ships have a sulfur content of 0.5% by mass or less, thereby reducing the burden on the environment and having excellent environmental performance.

In order to comply with the above regulations, it has become necessary to greatly modify the supply and demand balance of various fractions in refineries in order to reduce the sulfur content of various fractions used in fuel oil compositions. For example, high sulfur C heavy oil fractions (also referred to as “HSC heavy oil fractions”) with a relatively high sulfur content, including vacuum distillation residue fractions distilled from vacuum distillation towers, have been used in fuel oil compositions. It has come in handy as a product (see Patent Document 1, for example). However, since the vacuum distillation residue fraction has a high sulfur content, it is necessary to use a desulfurized fraction in order to reduce the sulfur content.

After undergoing various refining processes according to demand, crude oil is supplied with properties suitable for various uses. Focusing on the vacuum distillation residue fraction that has been widely used for fuel oil compositions, the vacuum distillation residue fraction is obtained by vacuum distillation of the atmospheric distillation residue fraction obtained by atmospheric distillation of crude oil. The vacuum distillation residue fraction is used alone or in combination with other heavy fractions such as fluid catalytic cracking residue fractions as HSC heavy oil fractions, as a raw material for fuel oil compositions as described above. It has been On the other hand, the atmospheric distillation residue fraction obtained by atmospheric distillation is hydrodesulfurized in a heavy oil direct desulfurization unit (also referred to as "RH unit") to obtain a low sulfur C heavy oil fraction with a low sulfur content. (also referred to as "LSC heavy oil fraction"), and if necessary, a cracked gasoline fraction or the like is obtained by fluid catalytic cracking treatment in a fluid catalytic cracking unit (FCC unit, RFCC unit, etc.).

When trying to suppress the amount of the vacuum distillation residue fraction used in the fuel oil composition, the fraction obtained by refining the vacuum distillation residue fraction, specifically, hydrodesulfurization in a heavy oil direct desulfurization unit (RH unit) Processed desulfurized heavy oil fraction (for example, the above-mentioned low-sulfur C heavy oil fraction (LSC heavy oil fraction)), a fraction obtained by subjecting the desulfurized heavy oil fraction to fluid catalytic cracking by a fluid catalytic cracking unit (FCC unit, RFCC unit, etc.) etc.) as fuel oil. Thus, in order to comply with the above regulations, it will be necessary to review the supply and demand balance of the entire refinery.
Then, as a means to review the supply and demand balance and respond to the above regulations, increase the processing amount of the vacuum residue fraction in the heavy oil direct desulfurization unit (RH unit), processing in the downstream fluid catalytic cracking unit (FCC unit, RFCC unit) an increase in the amount, etc.;

International Publication No. 2012/61019 Pamphlet

By the way, when increasing the throughput in the heavy oil direct desulfurization unit (RH unit), not only the metal concentration and sulfur concentration contained in the processed heavy oil fraction increase, but also the coke precursors increase and the fluid catalytic cracking unit Coke (also referred to as “hydrocarbons”) tends to adhere to fluid catalytic cracking catalysts used in (FCC units, RFCC units). Thus, the fluid catalytic cracking unit (FCC unit, RFCC unit) is affected by the performance of the heavy oil direct desulfurization unit (RH unit) upstream thereof.
Increased deposition of coke (hydrocarbons) on fluid catalytic cracking catalysts leads to increased loading of catalyst regeneration towers in fluid catalytic cracking units (FCC units, RFCC units). Specifically, air is used to regenerate the catalyst, and it is necessary to increase the amount of air supplied to the regeneration tower in order to increase the regeneration capacity of the catalyst. As a result, various problems such as an increase in the power required to supply air into the regeneration tower and insufficient capacity of the air blower arise.

Accordingly, an object of the present invention is to provide a method of operating a fluid catalytic cracking unit and a fluid catalytic cracking unit that improve the processing capacity of the fluid catalytic cracking unit while suppressing an increase in the load on the air blower.

The present inventors have made intensive studies to solve the above problems, and as a result, have found that the problems can be solved by the following inventions. That is, the present invention provides a method for operating a fluid catalytic cracking unit and a fluid catalytic cracking unit having the following configurations.

1. A method for operating a fluid catalytic cracking apparatus comprising a reaction tower for performing a reaction using a fluid catalytic cracking catalyst and a regeneration tower for regenerating the fluid catalytic cracking catalyst used in the reaction tower,
Regeneration of the fluid catalytic cracking catalyst is performed by supplying oxygen and air to the regeneration tower;
A method of operating a fluidized catalytic cracking unit.
2. 2. The method for operating a fluid catalytic cracking unit according to 1 above, wherein the regeneration of the fluid catalytic cracking catalyst is performed by supplying an oxygen-enriched mixed gas containing oxygen and air to the regeneration tower.
3. 3. The method for operating a fluidized catalytic cracking unit according to 1 or 2 above, wherein the amount of oxygen supplied is 0.5 parts by volume or more and 22.0 parts by volume or less with respect to 100 parts by volume of the air supplied.
4. 4. The method for operating a fluidized catalytic cracking unit according to any one of 1 to 3 above, wherein the feed oil containing the desulfurized heavy oil fraction is reacted with the catalyst in the reaction tower.
5. Fluid contact comprising a reactor for performing a reaction using a fluid catalytic cracking catalyst, a regeneration tower for regenerating the fluid catalytic cracking catalyst used in the reactor, and a supply means for supplying oxygen and air to the regeneration tower decomposition equipment.
6. 6. The fluid catalytic cracking apparatus according to 5 above, wherein the supply means comprises an oxygen supply means for supplying oxygen and an air supply means for supplying air.
7. 7. The above 5 or 6, wherein the supply means comprises mixing means for mixing the oxygen and the air to produce an oxygen-enriched mixed gas, and oxygen-enriched mixed gas supply means for supplying the oxygen-enriched mixed gas. fluid catalytic cracking unit.

ADVANTAGE OF THE INVENTION According to this invention, the operating method of a fluid catalytic cracking apparatus and fluid catalytic cracking apparatus which improve the processing capacity of a fluid catalytic cracking apparatus can be provided, suppressing the increase in the load of an air blower.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the preferable one aspect|mode of the fluid catalytic cracking apparatus used with the operating method of this embodiment. 4 is a graph showing the results of Example 1 and Comparative Example. 4 is a graph showing the results of Example 2 and Comparative Example.

[Method of operating fluidized catalytic cracking unit]
A method for operating a fluid catalytic cracking unit according to an embodiment of the present invention (hereinafter sometimes simply referred to as this embodiment) includes a reaction tower for performing a reaction using a fluid catalytic cracking catalyst, and a reaction tower used in the reaction tower. A method for operating a fluid catalytic cracking unit comprising a regeneration tower for regenerating the fluid catalytic cracking catalyst,
The regeneration of the fluidized catalytic cracking catalyst is performed by supplying oxygen and air to the regeneration tower.

As described above, due to an increase in the throughput of the heavy oil direct desulfurization unit (RH unit), the amount of coke precursors contained in the processed heavy oil fraction increases, so the load on the regeneration tower in the fluid catalytic cracking unit increases. That is, it is assumed that the load on the air blower for blowing the air used for regenerating the catalyst will increase. Furthermore, if the amount of air used for regeneration of the catalyst exceeds the capacity of the air blower, the amount of air supplied for regeneration will be insufficient, making it impossible to sufficiently regenerate the catalyst, resulting in fluid catalytic cracking. It is also assumed that the performance of the device itself is degraded.

In the method of operating the fluidized catalytic cracking unit of the present embodiment, in the regeneration of the catalyst in the regeneration tower, by simultaneously supplying oxygen in addition to the conventionally used air, (i) when the load on the regeneration tower increases It is possible to suppress an increase in the load on the air blower by maintaining the amount of air supplied, and (ii) to increase the load on the regeneration tower to an extent that cannot be achieved only by increasing the load on the air blower. . Here, the effect of the present invention, "improving the processing capacity of the fluid catalytic cracking unit while suppressing an increase in the load on the air blower" basically means the above (i) and (ii). However, the reduction in energy consumption due to the reduction in the amount of exhaust gas, which will be described later (iii), is also a secondary effect of the present invention.

In relation to the air blower, by simultaneously supplying oxygen in addition to the conventionally used air, (iii) when the load on the regeneration tower does not change, the amount of air supplied is reduced to reduce the load on the air blower. , is also possible. In addition, the operation method of the present embodiment can also reduce the amount of exhaust gas from the regeneration tower, so that the exhaust gas and the regenerated catalyst can be separated from each other by the cyclone in the regeneration tower. Therefore, when the throughput is increased, the separation capacity of the cyclone is not restricted, and the energy consumption of the fluid contact cracking apparatus can be reduced.
Thus, according to the operating method of the fluid catalytic cracking apparatus of this embodiment, it is possible to improve the processing capacity of the fluid catalytic cracking apparatus while suppressing an increase in the load on the air blower. It also becomes possible to reduce the energy consumption in the fluidized catalytic cracking apparatus.

(Configuration of fluidized catalytic cracking unit)
The configuration of the fluidized catalytic cracking apparatus used in the operating method of this embodiment will be described with reference to FIG. FIG. 1 shows a preferred embodiment of a fluidized catalytic cracking unit that can be used in the operating method of this embodiment.
The fluid catalytic cracking apparatus 1 shown in FIG. and supply means (air blower 41 (air supply means) and mixing means 42 for generating an oxygen-enriched mixed gas).

A riser 10 is provided at the bottom of the reaction tower 20 . The riser 10 includes a regenerated catalyst transfer line 33 for supplying the fluidized catalytic cracking catalyst (hereinafter sometimes simply referred to as "catalyst") regenerated in the regeneration tower 30, and a raw material supply line for supplying the raw material containing the raw material oil B. connected to line 11.
A pumping fluid A flows through the riser 10 . Also, the riser 10 is supplied with raw material obtained by adding steam C to the raw material oil B heated by the preheater 12 from the raw material supply line 11 . Therefore, the raw material containing the feed oil B and the steam C supplied into the riser 10 is regenerated in the regeneration tower 30, contacted with the catalyst supplied from the regenerated catalyst transfer line 33, and cracked by catalytic cracking reaction. Decomposition products E and catalyst obtained by decomposing the raw material pass through the riser 10 by the pumping fluid A and are supplied to the reaction tower 20 .

Reactor 20 includes cyclone 21 , cracked product discharge line 22 , stripper 23 and spent catalyst transfer line 24 .
The cracked product E obtained by cracking the raw material containing the raw material oil B in the riser 10 is supplied to the cyclone 21 provided in the reaction tower 20, and separated into the cracked product E and the catalyst in the cyclone 21 by centrifugal force. . The cracking product E is a fluidized catalytic cracking product of the feedstock, discharged from the cracking product discharge line 22, and utilized for desired applications. Steam D is supplied to the stripper 23, and in order to reduce the amount of coke (hydrocarbons) adhering to the catalyst surface in the regeneration tower 30, after removing the coke (hydrocarbons) adhering to the catalyst surface, the catalyst is spent. It is discharged from reactor 20 through catalyst transfer line 24 and transferred to regeneration tower 30 .

The regeneration tower 30 burns coke (hydrocarbons) adhering to the surface of the used catalyst separated in the cyclone 21 of the reaction tower 20 to regenerate the catalyst. The regeneration tower 30 has an air grid 31 , a cyclone 32 , a regeneration catalyst transfer line 33 and an exhaust gas line 34 .
The air grid 31 is a grid for supplying air or an oxygen-enriched mixed gas containing air and oxygen into the regeneration tower. In FIG. It is shown as supplying an oxygen-enriched mixed gas mixed with oxygen by means of a mixing means 42 to be generated into the regeneration tower. The air and oxygen supplied into the regeneration tower are used to burn the coke (hydrocarbons) from the spent catalyst transferred from the reaction tower 20 and having coke (hydrocarbons) adhered to the surface thereof to regenerate the catalyst. . Cyclone 32 separates the regenerated catalyst and exhaust gases from coke (hydrocarbon) combustion. The regenerated catalyst is then discharged from regeneration tower 30 via regenerated catalyst transfer line 33 and supplied to riser 10 . An exhaust gas containing carbon dioxide and SO 2 _X as main components is discharged from the regeneration tower 30 through an exhaust gas line 34 .

(Supply of oxygen and air)
In the method of operating the fluidized catalytic cracking unit of the present embodiment, oxygen and air are supplied to the regeneration tower for regeneration of the catalyst. The method of supplying oxygen and air is not particularly limited, and oxygen and air may be individually supplied to the regeneration tower, or as shown in FIG. may be fed to the regeneration tower.
When a fluidized catalytic cracking unit exists as an existing unit, it is preferable to mix oxygen and air in advance and supply them as shown in FIG. This is because it is sufficient to newly install the mixing means 42 for mixing oxygen to generate an oxygen-enriched mixed gas in the existing air supply line. Further, if oxygen and air are mixed in advance and supplied, local temperature rise in the regeneration tower can be suppressed as much as possible, so that more stable operation becomes possible.

The amount of oxygen supplied is preferably 0.5 parts by volume or more, more preferably 1.0 parts by volume or more, still more preferably 1.2 parts by volume or more, and even more preferably, with respect to 100 parts by volume of air supplied. 1.3 parts by volume or more, and the upper limit is preferably 22.0 parts by volume or less, more preferably 15.0 parts by volume or less, even more preferably 10.0 parts by volume or less, and even more preferably 5.0 parts by volume or less. is. The amount of oxygen supplied is the same whether oxygen and air are individually supplied to the regeneration tower or when oxygen and air are mixed in advance and supplied as an oxygen-enriched mixed gas.
When the oxygen supply amount is within the above range, it is possible to efficiently improve the processing capacity of the fluid catalytic cracking apparatus while suppressing an increase in the load on the air blower. In addition, when using an oxygen-enriched mixed gas, the need to use a special material suitable for the use of oxygen is reduced, so existing equipment such as piping for supplying air to the regeneration tower, supply to the regeneration tower If an air preheater or the like for preheating air is provided, these pipes and air preheater can be used as they are.

(raw material oil)
In the method for operating the fluid catalytic cracking unit of the present embodiment, the feedstock oil to be subjected to the reaction using the fluid catalytic cracking catalyst preferably contains a desulfurized heavy oil fraction.
The desulfurized heavy oil fraction is a low-sulfur heavy oil fraction (DSAR) obtained by hydrodesulfurization in a heavy oil direct desulfurization unit (RH unit). A heavy oil direct desulfurization unit (RH unit) is usually connected to an atmospheric distillation unit and a vacuum distillation unit, and is a unit that hydrodesulfurizes residual oil (heavy oil) obtained from these units using a catalyst. In this device, hydrodesulfurization and hydrocracking are carried out, and the resulting reaction product is separated from gas and liquid, and the liquid phase is separated into naphtha fraction, gas oil fraction, heavy oil fraction, etc. by separation operation such as distillation. The desired fractions are fractionated and recovered. The heavy oil fraction recovered here is the desulfurized heavy oil fraction (DSAR).

The heavy oil to be processed in the RH unit is not particularly limited, for example, atmospheric distillation residue (AR) of crude oil, vacuum distillation residue (VR), heavy cycle oil (HCO: Heavy Cycle Oil), fluid catalytic cracking residue High density petroleum fractions such as CLO (Clarified Oil), heavy gas oil, visbreaking oil, and bitumen may be mentioned, and these may be used alone or in combination.

Hydrodesulfurization and hydrocracking in the RH unit are usually carried out in the presence of a catalyst, and by adjusting various reaction conditions such as reaction temperature, reaction pressure, and liquid hourly space velocity, the desired desulfurization rate and heavy oil cracking rate can be obtained. can be achieved. Hydrodesulfurization and hydrocracking are not particularly limited, but are usually carried out at a reaction temperature of 300 to 450° C. under hydrogen pressure of usually 10 to 22 MPa, and the liquid hourly space velocity (LHSV) is usually 0.1 to 10 h ^{− 1} , and the hydrogen/heavy oil ratio is usually 200 to 10,000 Nm ³ /kL.

The feedstock for the fluidized catalytic cracking unit may contain fractions other than the desulfurized heavy oil fraction. Such fractions are not particularly limited. Desulfurized vacuum gas oil fraction (VHHGO) obtained by desulfurizing vacuum gas oil fraction etc. with indirect desulfurization equipment, deasphalted oil (DAO) obtained from indirect desulfurized heavy oil fraction and solvent deasphalting equipment, vacuum heavy oil fraction ( VR), coker gas oil, and various heavy oils such as coker bottom oil.

The content of the desulfurized heavy oil fraction in the feedstock can be appropriately changed according to the balance between supply and demand, and is not particularly limited. It may be vol% or more, and the upper limit may be 100 vol%, that is, the whole amount may be a desulfurized heavy oil fraction, or, for example, 90 vol% or less, 75 vol% or less, or 50 vol% or less. good. If the content of the desulfurized heavy oil fraction in the feedstock is within the above range, the balance between supply and demand can be easily met, and stable operation of the fluidized catalytic cracking unit is possible.

(fluid catalytic cracking catalyst)
The fluid catalytic cracking catalyst used in the method for operating the fluid catalytic cracking unit of the present embodiment is not particularly limited, and a so-called equilibrium catalyst can be used, and a general-purpose commercial product can be used, You may use what was prepared. For example, catalysts such as various zeolites, alumina, clay minerals, silica, etc., or these as porous inorganic oxide carriers, vanadium, other manganese, manganese, magnesium, calcium, cobalt, zinc, copper, titanium, aluminum, nickel, iron , chromium, lanthanum, yttrium, scandium, niobium, tantalum, molybdenum, and tungsten.

(Operating conditions)
As for the operating conditions of the reaction tower, the outlet temperature of the reaction tower is preferably 450° C. or higher, more preferably 470° C. or higher, still more preferably 490° C. or higher, and the upper limit is preferably 550° C. or lower, more preferably 540° C. 530° C. or less, more preferably 530° C. or less. Under such reaction conditions, the progress of the cracking reaction is further promoted, and the amount of coke (hydrocarbons) on the fluidized catalytic cracking catalyst can be further reduced, and the amount of coke (hydrocarbons) brought into the regeneration tower can be reduced. can be further reduced. Therefore, stable operation becomes possible, and the yield of fluid catalytic cracking gasoline corresponding to the cracked product E is improved.

The operating temperature in the regeneration tower is preferably 615° C. or higher, more preferably 620° C. or higher, and the upper limit is preferably 645° C. or lower, more preferably 635° C. or lower. When the regeneration temperature is 615° C. or higher, the coke (hydrocarbon) can be sufficiently combusted, thereby improving the catalytic activity. On the other hand, if the regeneration temperature is 645° C. or lower, generation of steam due to combustion of coke (hydrocarbon) can be further suppressed, and deterioration of catalytic activity (hydrothermal deterioration) can be further suppressed, resulting in improved catalytic activity. In addition, since the cracking rate is improved without reducing the circulation amount of the catalyst, the yield of the fluid catalytic cracking gasoline corresponding to the cracked product E is improved.

[Fluid catalytic cracking equipment]
The fluidized catalytic cracking apparatus of the present embodiment includes a reaction tower for performing a reaction using a fluidized catalytic cracking catalyst, a regeneration tower for regenerating the fluidized catalytic cracking catalyst used in the reaction tower, and oxygen and air in the regeneration tower. and supply means for supplying. The fluid catalytic cracking apparatus of the present embodiment is preferably employed in the method of operating the fluid catalytic cracking apparatus of the present embodiment described above, that is, the method of operating the fluid catalytic cracking apparatus of the present embodiment is It can be easily implemented by the device.

A preferred embodiment of the fluid catalytic cracking apparatus of the present embodiment includes the fluid catalytic cracking apparatus shown in FIG. 1 described in the operating method of the fluid catalytic cracking apparatus of the present embodiment.
The structures of the reaction tower and the regeneration tower provided in the fluid catalytic cracking apparatus of the present embodiment are as described in the operating method of the fluid catalytic cracking apparatus of the present embodiment.

(Supply Means for Supplying Oxygen and Air to Regeneration Tower)
The fluidized catalytic cracking apparatus of the present embodiment is provided with supply means (hereinafter also referred to as unit "supply means") for supplying oxygen and air to the regeneration tower.
For example, when oxygen and air are individually supplied to the regeneration tower, the fluidized catalytic cracking apparatus of the present embodiment includes, as supply means, an oxygen supply means for supplying oxygen and an air supply means for supplying air. . A specific configuration of the air supply means for supplying air includes a configuration having piping to the air blower and the regeneration tower shown in FIG. Further, a specific configuration of the oxygen supply means for supplying oxygen includes a configuration having an oxygen production device for producing oxygen and piping for supplying oxygen from the device to the regeneration tower. For example, when the fluid catalytic cracking apparatus of the present embodiment is installed in a plant such as a refinery, there is a line that supplies oxygen to the plant, and if this can be used, there is no need to separately install an oxygen production apparatus. do not have.

Further, when oxygen and air are mixed and supplied to the regeneration tower as an oxygen-enriched mixed gas, the supply means is configured as shown in FIG. It is preferable to adopt a configuration having a mixing means 42 for generating a mixed gas as a main component. Specifically, the supply means shown in FIG. oxygen-enriched mixed gas supply means having piping up to the regeneration tower 30 .

The specific configuration of the mixing means 42 is not particularly limited as long as it is configured to mix oxygen and air. A configuration such as a mixer that can be newly installed by connecting flanges may be used, or a configuration in which a nozzle for supplying oxygen is simply inserted into an air pipe may be used.

The air supply means may have a flow meter for measuring the flow rate of the air supplied to the regeneration tower and a flow control valve for adjusting the flow rate, and the oxygen supply means may also have a flow meter and a flow control valve. good.
Further, the oxygen-enriched mixed gas supply means may have a preheater for preheating the oxygen-enriched mixed gas, and has a flow meter and a flow control valve for measuring the flow rate of the oxygen-enriched mixed gas to the regeneration tower. You may have

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples.

(Comparative example)
The fluidized catalytic cracking reaction of feedstock oil was carried out as follows.
A fluid catalytic cracking apparatus having the configuration shown in FIG. 1 was used. A feedstock oil containing the following fraction and having the properties shown in Table 1 is supplied to a reaction tower of a fluid catalytic cracking unit that circulates the following fluid catalytic cracking catalyst, and the feedstock oil throughput (7155 kL / day) , and the feedstock oil was cracked while setting the amount of fluid catalytic cracking catalyst input (1.6 tons/day). Here, the linear velocity in the cyclone of the regeneration tower was operated so as not to exceed the upper limit of 23.6 m/s.
(Properties of raw material oil)
Desulfurized heavy oil fraction content: 30% by volume (density: 0.925 g/cm ³ , sulfur content: 0.280 mass%, residual carbon content: 3.99 mass%)
Desulfurized light oil fraction content: 70% by volume (density: 0.887 g/cm ³ , sulfur content: 0.207 mass%, residual carbon content: 0.03 mass%)
(fluid catalytic cracking catalyst)
Components: A catalyst containing 25% by mass of ultra-stable Y-type zeolite, 5% by mass of alumina, 60% by mass of clay mineral, 5% by mass of silica, and 5% by mass of other impurities was used.
Specific surface area: 250 m ² /g
Pore volume: 0.20 cm ³ /g
(Operating conditions of fluidized catalytic cracking unit)
Reactor outlet temperature (ROT): 518°C
Operating temperature of regeneration tower: 632°C
Catalyst circulation amount: 51 tons/min
Air supply amount: 144×10 ³ Nm ³ /h

(Example 1)
Following the above comparative example, the operation was carried out in the same manner as in the comparative example except that the air supply amount of 144×10 ³ Nm ³ /h was changed to 137×10 ³ Nm ³ /h and the oxygen supply amount was changed to 1890 Nm ³ /h.

(Example 2)
Following the above comparative example, the operation was carried out in the same manner as in the comparative example except that the air supply amount of 144×10 ³ Nm ³ /h was changed to 123×10 ³ Nm ³ /h and the oxygen supply amount was changed to 3460 Nm ³ /h.

For Example 1 and Comparative Example, the flow rate of oxygen gas, the linear velocity (m / s) in the cyclone of the regeneration tower, and the treatment ratio (% by volume) of the low-sulfur heavy oil fraction (DSAR) over time are shown in FIG. shown in
According to FIG. 2, in the comparative example in which only air was supplied, the linear velocity of the regeneration tower cyclone was 23.6 m / s at a low sulfur heavy oil fraction (DSAR) treatment rate of 30%, but the air When oxygen was supplied together, the linear velocity in the cyclone of the regeneration tower decreased to about 22.0 m / s, and there was a margin in the regeneration performance of the catalyst, so the treatment ratio of the low sulfur heavy oil fraction (DSAR) was 35%. rose to In addition, since the linear velocity in the cyclone of the regeneration tower has a margin up to the standard of 23.6 m/s, it is considered possible to further improve the treatment ratio. Moreover, it was confirmed that the air supply amount could be reduced by 4.9%, and the load on the air blower could be reduced.

FIG. 3 shows changes over time in the flow rate of oxygen gas, the linear velocity (m/s) in the cyclone of the regeneration tower, and the treatment ratio (% by volume) of the low-sulfur heavy oil fraction (DSAR) in Example 2 and Comparative Example. is shown. According to FIG. 3, in Comparative Example 1 in which only air was supplied, the linear velocity of the regeneration tower cyclone was 23.6 m/s as in Example 1, but when oxygen was supplied together with air, the regeneration tower It was confirmed that the linear velocity in the cyclone was reduced to about 20.5 m/s. From this, it is considered that the processing ratio of DSAR can be increased in the case of the second embodiment as well, compared to the first embodiment. It was also confirmed that the amount of air supplied could be reduced by 14.6% and the load on the air blower could be reduced.

As described above, from the results of Examples and Comparative Examples, it is possible to improve the processing capacity of the fluid catalytic cracking unit while suppressing an increase in the load on the air blower by the operating method of the fluid catalytic cracking unit of the present embodiment. One thing has been confirmed.

Claims (7)

A method for operating a fluid catalytic cracking apparatus comprising a reaction tower for performing a reaction using a fluid catalytic cracking catalyst and a regeneration tower for regenerating the fluid catalytic cracking catalyst used in the reaction tower,
Regeneration of the fluid catalytic cracking catalyst is performed by supplying oxygen and air to the regeneration tower;
A method of operating a fluidized catalytic cracking unit. 2. The method of operating a fluid catalytic cracking unit according to claim 1, wherein regeneration of said fluid catalytic cracking catalyst is performed by supplying an oxygen-enriched mixed gas containing oxygen and air to said regeneration tower. 3. The method of operating a fluidized catalytic cracking unit according to claim 1, wherein the amount of oxygen supplied is 0.5 parts by volume or more and 22.0 parts by volume or less with respect to 100 parts by volume of the air supplied. The method of operating a fluidized catalytic cracking unit according to any one of claims 1 to 3, wherein the catalyst in the reaction tower reacts the feed oil containing the desulfurized heavy oil fraction. Fluid contact comprising a reactor for performing a reaction using a fluid catalytic cracking catalyst, a regeneration tower for regenerating the fluid catalytic cracking catalyst used in the reactor, and a supply means for supplying oxygen and air to the regeneration tower decomposition equipment. 6. The fluid catalytic cracking unit of claim 5, wherein said supply means comprises an oxygen supply means for supplying oxygen and an air supply means for supplying air. 7. The method according to claim 5 or 6, wherein said supply means comprises mixing means for mixing said oxygen and said air to produce an oxygen-enriched mixed gas, and oxygen-enriched mixed gas supply means for supplying said oxygen-enriched mixed gas. Fluid catalytic cracking unit as described.

Images