RU2532547C1 - Method of removing air from catalyst cooler and apparatus therefor - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to catalyst regeneration and specifically to a catalyst regenerator. The disclosed regenerator comprises: a housing having an inlet opening for the catalyst and combustion gas, an outlet opening for the regenerated catalyst, an outlet opening for feeding the catalyst into the cooler and an outlet opening for effluent gas; a catalyst cooler, having an inlet opening for a hot catalyst, linked to the outlet opening of said regenerator housing, which serves to feed the catalyst into the cooler, a gas distributor, an air vent, an outlet opening for the cooled catalyst and a plurality of heat-exchange pipes therein for carrying the coolant; and an air pipe which links said air vent with said regenerator housing. The invention also relates to a method for catalyst regeneration in said regenerator.

EFFECT: disclosed catalyst regenerator and regeneration method using same enable to efficiently use air for fluidising a hot catalyst in catalyst coolers equipped with regenerators.

10 cl, 1 dwg

Description

FIELD OF THE INVENTION

The invention relates to catalyst regeneration in a fluidized catalyst cracker (FCC).

State of the art

Fluidized catalyst cracking (FCC) is a hydrocarbon conversion process that is carried out by contacting a hydrocarbon with a catalyst in the form of a finely divided particulate material that is in the reaction zone in a fluidized state. The catalytic cracking reaction, as opposed to hydrocracking, is carried out without significant addition or consumption of hydrogen. As the cracking reaction proceeds, a substantial amount of high-carbon material called coke is deposited on the catalyst. In the process of high-temperature regeneration carried out in the regeneration zone, coke is burned from the catalyst. The catalyst on which coke is deposited, referred to herein as a coked catalyst, is continuously removed from the reaction zone and replaced with a catalyst substantially free of coke from the regeneration zone. The fluidization of the solid particles of the catalyst using various gaseous streams allows the catalyst to be transported between the reaction zone and the regeneration zone.

Conventional regenerators typically comprise a housing having an inlet for a coked catalyst, an outlet for a regenerated catalyst, and a combustion gas distributor for supplying air or other oxygen-containing gas to the catalyst bed that is located inside the housing. Cyclone separators trap the catalyst carried away by the off-gas stream before the off-gas is removed from the regenerator body.

There are several types of catalyst regenerators currently in use. A conventional stationary fluidized bed regenerator contains only one chamber in which air sparges through a dense catalyst bed. In this case, the coked catalyst is added, and the regenerated catalyst is withdrawn from the same dense catalyst bed. A relatively small amount of catalyst is carried away in the off-gas stream exiting said dense catalyst bed.

Two types of regenerators have two chambers. Two-stage stationary fluidized beds use two chambers. The coked catalyst is added to the dense layer in the first, upper chamber, and it is partially regenerated by air. The partially regenerated catalyst is transported into a dense layer in the second lower chamber and it is completely regenerated by air. The completely regenerated catalyst is removed from the second chamber.

Complete regeneration of the catalyst can be carried out in a regenerator in which coke is burned, operating with a fast rarefied fluidized bed. The coked catalyst is added to the lower chamber and transported upward by air in a fast fluidized bed mode, while the catalyst is completely regenerated. The regenerated catalyst is separated from the exhaust gas by means of a primary separator when introduced into the upper chamber, in which the regenerated catalyst and the exhaust gas are separated from each other. Only a small portion of the air added to the regenerator body is added to the upper chamber. US Pat. Nos. 4,197,189 and 4,336,160 describe a combustion zone in a vertical riser pipe (elevator reactor), which maintains the conditions of a fast fluidized bed for complete combustion without the need for additional combustion in a catalyst bed collected from the top of the riser.

Afterburning is a phenomenon that occurs when a hot off-gas that is separated from a regenerated catalyst contains carbon monoxide, which is burned to form carbon dioxide. Burning in the upper separation chamber, which contains the exhaust gases that have been separated from the catalyst, can be dangerous, while providing a rarefied phase of the catalyst. In this rarefied phase, the catalyst is not in sufficient quantity in order to be used as a heat absorber, ensuring the absorption of heat released during combustion. Therefore, the surrounding equipment is exposed to higher temperatures, which create a risk of damage to the equipment, and an atmosphere can be created that promotes the formation of nitrogen oxides.

To cool the regenerated catalyst, catalyst coolers are used which enable the regenerator and reactor to operate under independent conditions. In catalyst coolers, the hot regenerated catalyst is cooled by indirect heat exchange with water, which evaporates and turns into water vapor. The resulting water vapor is removed from the catalyst cooler for other purposes, while the cooled catalyst is returned to the regenerator. The air used to fluidize the catalyst in the catalyst cooler may be directed to a regenerator.

The prior art catalyst cooler with an air hole communicating with the upper chamber of the regenerator body. The air for fluidizing the catalyst in the cooler directed to the upper chamber of the regenerator may provide an oxidizing agent for afterburning.

Ways are being found for the efficient use of air to fluidize the hot catalyst in the catalyst coolers that the regenerators are equipped with.

Disclosure of invention

In one embodiment related to the method, an object of the invention is a method for regenerating a catalyst, comprising burning coke from a catalyst in a combustion chamber located in a regenerator body. The off-gas is separated from the catalyst in a separation chamber. The hot catalyst is transported from the regenerator body through the inlet for the hot catalyst to the catalyst cooler. The hot catalyst diverted from the regenerator body is cooled in a catalyst cooler. The catalyst is fluidized in a catalyst cooler with air. The cooled catalyst is discharged from the catalyst cooler. Air is sent from the catalyst cooler to the regenerator body. A distinctive feature of the present invention is the removal of air from the catalyst cooler into the combustion chamber.

In another embodiment related to the method, an object of the invention is a catalyst regeneration method comprising burning coke from a catalyst in a combustion chamber of a regenerator body. The regenerated catalyst is separated from the combustion products in the separation chamber of the regenerator body. The hot catalyst is transported from the separation chamber to the catalyst cooler through the inlet for the hot catalyst. The hot catalyst diverted from the regenerator body is cooled in a catalyst cooler. The catalyst is fluidized in a catalyst cooler with air. The cooled catalyst is transported to the combustion chamber. Air is taken from the catalyst cooler to the regenerator body separately from the cooled catalyst. A distinctive feature of the invention is the removal of air from the catalyst cooler into the combustion chamber.

According to yet another embodiment, an object of the invention is a catalyst regeneration method comprising transporting a coked catalyst and combustion gas to a regenerator body. Coke is burned from the coked catalyst in the combustion chamber of the regenerator body. The catalyst is separated from the exhaust gas in a separation chamber. The hot catalyst is transported to the catalyst cooler from the regenerator body through the catalyst inlet. The hot catalyst diverted from the regenerator body is cooled in a catalyst cooler. The catalyst is fluidized in a catalyst cooler with air. The cooled catalyst is discharged from the catalyst cooler. Air from the catalyst cooler is discharged into the regenerator body separately from the cooled catalyst and from the inlet for the hot catalyst. The cooled catalyst discharged from the catalyst cooler is transported via a riser to a combustion chamber. A distinctive feature of the present invention is the removal of air from the air hole into the combustion chamber.

In one embodiment related to the device, an object of the invention is a catalyst regenerator comprising a regenerator body having an inlet for catalyst and combustion gas, an outlet for regenerated catalyst, an outlet for exhausted catalyst cooler, an outlet for exhaust gas, an upper chamber, and bottom camera. The device also contains a catalyst cooler having an inlet for hot catalyst, which communicates with an outlet in the housing of the regenerator for the catalyst discharged into the cooler. The catalyst cooler contains a gas distributor, an air hole, an outlet for the catalyst to be directed to the cooler, and a large number of heat transfer tubes in the catalyst cooler for conveying the coolant. The air pipe communicates the air hole with the regenerator body. A distinctive feature of the present invention is that the air pipe communicates an air hole with a lower chamber in the regenerator body.

In another embodiment related to the device, an object of the invention is a catalyst regenerator comprising a housing having an inlet for a catalyst and a combustion gas, an outlet for a regenerated catalyst, an outlet for a catalyst guided to the cooler, an outlet for the exhaust gas, an upper chamber and a lower the camera. The device also contains a catalyst cooler having an inlet for hot catalyst, which is in communication with the specified outlet for directed to the catalyst cooler. The catalyst cooler is equipped with a gas distributor and contains an air hole located above the inlet for the hot catalyst to form a separation section, an outlet for the catalyst directed to the cooler, and a large number of heat transfer pipes located in the catalyst cooler for transporting the heat carrier. The air pipe communicates the air hole with the regenerator body. A distinctive feature of the present invention is that the air pipe communicates the air hole with the upper chamber in the regenerator body.

According to another embodiment related to the device, an object of the invention is a catalyst regenerator comprising a regenerator housing having an inlet for catalyst and combustion gas in a combustion chamber, an outlet for regenerated catalyst, an outlet for exhaust gas in a separation chamber and an outlet in the separation chamber for the catalyst directed to the cooler. The device also contains a catalyst cooler having an inlet for a hot catalyst that communicates with an outlet for a catalyst directed to the cooler, which is provided in the regenerator body. The catalyst cooler is equipped with an air hole, an outlet for the cooled catalyst and a large number of heat transfer tubes in the catalyst cooler for transporting the coolant. The air pipe communicates the air hole with the regenerator body. A distinctive feature of the present invention is that the air pipe communicates with the combustion chamber.

Drawing - schematically shows a catalytic cracking unit (FCC) in accordance with the present invention.

The implementation of the invention

The inventors have found that the removal of air from the catalyst cooler to the lower chamber of the regenerator, instead of its removal to the upper chamber, minimizes the afterburning that can occur when the air is removed from the cooler to the upper chamber of the regenerator. The air supply to the lower chamber allows using it when burning precipitated coke on the spent catalyst.

The drawing shows the installation of 8 FCC, which can be used to conduct the FCC process. The hydrocarbon feed can be injected using distributors 10 into the riser reactor 20, where it is in contact with the catalyst. In general, the feedstock may be cracked in an elevator reactor 20 in the presence of a catalyst to produce a cracked product stream.

The traditional feedstock for the FCC process is a suitable feed to the riser reactor 20. The most common of these feedstocks is “vacuum gas oil” (VGO), which is typically a hydrocarbon material boiling in the temperature range 343 to 552 ° C (650 to 1025 ° F) obtained by vacuum fractionation of the residue of atmospheric distillation. Heavy hydrocarbon feeds may also be used in the present invention. Conventional FCC process feeds can be vaporized and injected into the elevator reactor using valves 10.

As shown in the drawing, the regenerated catalyst is fed into the elevator reactor 20 from the outlet riser 18 of the regenerator. In one embodiment, the carrier gas (gas for gas lift) may be an inert gas, such as water vapor, that can be dispensed by the carrier gas distributor 6 to transport the catalyst upward from the bottom portion 14 of the riser reactor 20. The hydrocarbon feed sprayed by the manifold 10 is in contact with fluidized catalyst and moves up in the elevator reactor 20, while the hydrocarbon feed is cracked to produce cracked products including lighter hydrocarbons. The cracked products and spent catalyst enter the reactor vessel 70, then are discharged from the top of the elevator reactor 20 through the outlet 72 and are separated into a vapor stream containing cracked products and a plurality of solid particulate catalyst coated with a substantial amount of coke and commonly referred to as spent catalyst. The design of the vortex sleeve 74 at the end of the elevator reactor 20 can further increase the initial separation of the catalyst and cracked hydrocarbon products by imparting a tangential flow rate to the mixture of the effluent catalyst and vapor cracking products. A swirl sleeve 74 is installed in the upper part of the separation chamber 76, and in the lower part of the separation chamber 76 there is a stripping zone 78. The catalyst separated by the swirl sleeve 74 falls down into the stripping zone 78.

A stream of cracked hydrocarbon vapor products containing cracked hydrocarbons including naphtha, light olefins, and some catalyst may exit the separation chamber 76 through a gas pipe 80 communicating with cyclones 82. The cyclones 82 may remove remaining catalyst particles from the vapor stream to reduce particle concentration to very low levels. The vaporous product stream may exit from the top of the reactor vessel 70 through the outlet 84. The catalyst separated by cyclones 82 is returned to the reactor vessel 70 through the cyclone downpipe and enters the dense bed 86, where the catalyst will pass through the openings 88 in the chamber and enter to zone 78 steaming.

In the stripping zone 78, the adsorbed and flux-carried hydrocarbons are removed from the catalyst by countercurrently contacting with an inert gas, such as water vapor, using disk reflectors 90, if necessary. Water vapor can enter the stripping zone 78 through a distributor 92. The coked catalyst is transported to the catalyst regenerator 30 via the spent catalyst conduit 94, wherein the catalyst flow is controlled by a control valve. In addition, a certain amount of spent catalyst without regeneration can be returned through a pipe for recycling spent catalyst (not shown) back to the elevator reactor 20 below the raw material distributors 10.

As shown in the drawing, the coked catalyst enters the catalyst regenerator 30 through the inlet 32, and in the regenerator, coke is usually burned from the surface of the solid particles of the catalyst due to contact with an oxygen-containing gas. Oxygen-containing combustion gas enters from below the regenerator 30 through an inlet 34 into the combustion gas distributor 36. The off-gas and stream-carried catalyst is transported upward through the regenerator 30. Exhaust gas leaves the regenerator through the exhaust gas outlet 38.

The catalyst regenerator 30 comprises a housing 40 in which there is a lower chamber 42 and an upper chamber 44. The catalyst regenerator may be a two-stage regenerator in which air enters the upper chamber 44 of the first stage and the lower chamber 42 of the second stage. In a two-stage regenerator, 20 to 40 mass% of air is supplied to the lower chamber. The oxygen-depleted air from the lower chamber and the remainder of all air supplied to the catalyst regenerator enter the upper chamber. The spent catalyst first enters the chamber 44 of the first stage. The partially regenerated catalyst is then transported down to the second stage chamber 42 to contact with fresh air and complete the regeneration process.

The catalyst regenerator 30 may also be a regenerator with a combustion chamber, as shown in the drawing. In the regenerator configured with the combustion chamber, the spent catalyst enters the lower chamber 42, called the combustion chamber, in which coke is burned from the catalyst, and then the catalyst and exhaust gas are transported from the lower chamber 42 to the upper chamber 44, called the separation chamber. Initially, the catalyst is separated from the combustion products by means of a primary separator, such as a T-shaped otveivat 50. The entrained particles of the catalyst are separated and removed from the upward flow of exhaust gas using regenerator cyclones 52, 54 or other means before the exhaust gas leaves the regenerator body through the outlet 38 for exhaust gas. Burning coke from solid catalyst particles raises the temperature of the catalyst. The separated catalyst is collected in a dense bed 56, which is fluidized by air supplied from the distributor 58. The separated catalyst can be discharged from the regenerator body through the outlet for the regenerated catalyst 16 to the outlet riser 18 of the regenerator. The catalyst can be transported through the outlet riser 18 of the regenerator to the lower section 14 of the elevator reactor 20, while the flow of the catalyst is controlled by a control valve.

The regenerated catalyst coming from outlet riser 18 will typically have a temperature in the range of 649 to 760 ° C. (1200 to 1400 ° F.). If air is used as the oxygen-containing gas, the dry air flow rate in the regenerator may be in the range from 8 to 15 kg / kg of coke. The hydrogen content in the coke can be from 4 to 8 wt.%, And the sulfur content in the coke from 0.6 to 3.0 wt.%.

At least one catalyst cooler 100 is used to cool the regenerated catalyst. In the regenerator 30 with the combustion chamber, the catalyst from the upper chamber 44 is transported through the outlet 102 for the catalyst to be directed to the cooler and the hot catalyst conduit 104 to the catalyst cooler 100, which enters through the inlet 106 for the hot catalyst. The outlet 102 for the catalyst to be directed to the cooler is provided in the upper chamber, and the hot catalyst is removed from the upper chamber 44 for transporting to the inlet 106 for the hot catalyst. Although only one catalyst cooler is shown in the drawing, more than one catalyst cooler can be used according to the invention.

The catalyst cooler 100 shown in the drawing is a direct-flow type cooler. In the catalyst cooler 100, catalyst heat exchange pipes 120 are arranged that cool the catalyst before it is discharged from the catalyst cooler 100 through the cooled catalyst outlet 110 to a cooled catalyst conduit 108. The use of heat exchange tubes 120 allows you to remove and remove heat from the catalyst, which is released when burning coke in the body 40 of the regenerator. Preferably, from 50 to 250 heat transfer tubes 120 are located in the catalyst cooler 100, more preferably from 75 to 200 heat transfer tubes 120 are used. Typically, heat from the catalyst is removed to generate water vapor, which can be used elsewhere in the refinery. The catalyst control valve 112 controls the amount of chilled catalyst discharged from the chilled catalyst outlet 110 and passing through the chilled catalyst conduit 108 and therefore the amount of hot catalyst entering the cooler 100 from the regenerator body 40, and thereby the control valve 112 controls the temperature inside the regenerator body 40.

The regenerated catalyst entering the catalyst cooler 100 through the inlet 106 for the hot catalyst contacts the heat exchanger tubes 120. The catalyst moves downward through the catalyst cooler 100, passes into the bottom of the cooler, and exits through the cooled catalyst outlet 110 below the specified inlet 106 for hot catalyst.

The catalyst cooler 100 is typically a “cold wall surrounded” cooler. The term "surrounded by a cold wall" means that the metal casing (shell) 128 of the cooler 100 is coated with an internal heat-resistant insulating lining. However, in one embodiment, the casing 128 can be made without using a heat-resistant insulating lining, and therefore, the cooler is considered “surrounded by a hot wall”. Additionally, the elements of the cooler 100 may be further provided with an abrasion resistant coating. The housing 128 of the cooler 100 may be made of stainless steel.

The catalyst cooler 100 includes an inlet manifold 114 and an outlet manifold 130. The lower tube plate 118 can be bolted between the flange on the upper end of the bottom 122 of the cooler 100 and the lower flange on the lower end of the output manifold 130. The upper tube plate 132 can be bolted between the flange on the upper end of the outlet manifold 130 and on the lower end of the housing 128, which forms a cooler 100. Grilts 140 are horizontally mounted in the catalyst cooler 100 to provide stiffening beam heat exchange tubes 120 which are oriented along the vertical axis 100 of the catalyst cooler. Said gratings 140 may form openings through which heat exchange tubes are passed. At least two gratings 140 can be placed in each catalyst cooler 100. The gratings are attached to the heat exchange tubes 120 and connected to each other using vertical support rods, which can be made of the same material as the heat transfer tubes 120. The gratings 140 and heat exchange tubes 120 are capable of joint thermal expansion, if necessary, if there is no connection between them.

In one embodiment, the coolant is process water, but it is contemplated to use another type of coolant, including water with additives that affect the boiling point of that coolant. The specified process water enters the inlet manifold 114 through a nozzle 116 for supplying a cooling medium located near the bottom or bottom of the catalyst cooler 100. In one embodiment, an inlet manifold 114 is formed between the lower tube plate 118 and the bottom 122 of the cooler. Preferably, the heat exchange pipes 120 with the catalyst have an inlet and outlet near or near the bottom of the cooler 100. Preferably, the heat transfer pipes 120 are bayonet type pipes, each of which comprises an inner pipe 124 and an outer pipe 126. The inner pipe 124 passes inside and through most the length of the outer pipe 126. The inner pipe 124 of the heat exchanger pipe 120 is attached to the lower tube plate 118, passes through this tube plate and protrudes upward. The inlets of the inner tubes 124 are in fluid communication with the inlet manifold 114. The process water entering the inlet manifold 114 is directed upward through the inner tube 124 of the bayonet heat exchange pipe 120. The process water flows upward through the inner tube 124 and exits through the outlet openings of the inner tubes 124. Then, the process water reverses its direction of motion and flows downward along the outer tube 126, which extends externally to the inner tube 124. The catalyst contacts the outer surface of the outer tube 126 of the heat exchange tubes 120 and there is heat exchange of the outer surface with the catalyst.

The heat from the catalyst is transferred by indirect (through the wall) heat exchange to the process water flowing in the outer pipes 126. Due to indirect heat exchange, the temperature of the process water in the outer pipes 126 rises, and the process water is converted at least partially into water vapor. By contacting the outer pipes 126, the temperature of the catalyst, which drops down in the catalyst cooler 100, decreases. Heated process water and water vapor from the outer pipes 126 exit the outlets of the outer pipes 126 and are sent to an output manifold 130 formed between the upper pipe plate 132 and the lower pipe board 118 in the catalyst cooler 100. Outer tubes 126 are attached to the upper tube plate 132, pass through this tube plate, and protrude upward from it. The outlets of the outer pipes 126 are in fluid communication with the outlet manifold 130. The fluid entering the outlet manifold 130 can then be transported from the catalyst cooler 100 through a nozzle 136 to a separation vessel in which steam and heated process water are separated from each other. The cooled catalyst is then discharged from the catalyst cooler 100 through the cooled catalyst outlet 110 to a conduit 108 that communicates the catalyst cooler to the regenerator body 40 via the catalyst recirculation valve 112. In one aspect, the chilled catalyst conduit 108 communicates with the chimney 150. A fluidizing gas is supplied to the chimney 150 to lift and feed the chilled catalyst from the chimney 150 to the regenerator body 40, preferably to the lower chamber of the regenerator 30. The catalyst distributor 152 may through openings distribute the catalyst inside the regenerator body 40.

The fluidizing gas in the catalyst cooler 100 is also directed downward with a nozzle distributor 138. Preferably, the distributor 138 is located above the heat exchanger tubes 120, with the nozzles directing the fluidizing gas in the catalyst cooler 10 downward. Gas, such as air, is used to fluidize the solid catalyst particles entering the catalyst cooler 100 through the inlet 106 for the hot catalyst. The flow rate of the fluidizing gas must be high enough to maintain the catalyst in a fluidized state. The fluidizing gas used in the catalyst cooler 100 improves the heat transfer between the catalyst and the heat transfer pipes 120 by generating turbulence, which increases the heat transfer coefficient between the catalyst and the heat transfer pipes 120. The two existing ways of controlling the temperature of the circulating catalyst are to control either the amount of catalyst, passing through the catalyst cooler 100, using the catalyst recirculation valve 112, or the flow rate of a fluidizing gas, is distributed of the catalyst in the cooler 100 through the distributor 138.

At the top of the catalyst cooler 100, there is an air hole 144 that allows fluidizing gas to exit the catalyst cooler. The air pipe 146 communicates the air hole 144 with the regenerator body through the outlet 154 for the exhaust gas. In one aspect, the air tube 146 communicates with the lower chamber 42 of the regenerator body 40. Air enters the lower chamber 42 separately from the cooled catalyst discharged into the cooled catalyst conduit 108 and the hot catalyst entering through the inlet 106 for the hot catalyst. Accordingly, the air leaving the catalyst cooler passes into the lower regenerator chamber 42, where it can be used to burn coke from the spent catalyst. The supply of fluidizing air to the lower chamber 42 is an improvement over the supply of air to the upper chamber 44, since the air, after burning it, does not contribute to the coke burning process in the upper chamber 44, but contributes to the burning of coke in the lower chamber 42. Air passing through the air pipe 146, after being fed from said air hole 144 and before entering said lower chamber 42 of said regenerator body 40, is directed downward. In one embodiment, the air tube may direct fluidizing air leaving catalyst cooler 100 up, then laterally, then down, and then laterally air enters the lower chamber 42 of the regenerator body 40. In this case, the inlet 154 for the gas discharged from the cooler is located below the air hole 144.

The separation zone 148 may be located in the catalyst cooler 100 between the inlet for the hot catalyst and the air hole 144 and above the gas distributor 138. The separation zone 148 is the volume in which the catalyst can be separated from the fluidizing gas before the gas leaves the air hole 144. Heat transfer pipes 120 are located below the separation zone 148. In one aspect, the air hole 144 is located above the specified inlet 106 for the hot catalyst, forming thus dividing zone 148.

Heat transfer tubes can be made of an alloy of chromium, molybdenum and iron, since this alloy is corrosion-resistant against traces of chlorides contained in process water, if it is used as a heat transfer fluid.

The zeolite molecular sieves used in the conventional FCC process have a large average pore size and are suitable for the present invention. Molecular sieves with large pore sizes, the effective hole diameter of which is more than 0.7 nm, are formed by more than ten-membered and usually twelve-membered ring structures. Suitable large pore molecular sieves include artificial zeolites, such as type X and type Y zeolites, mordenite and faujasite. Preferred are type X zeolites with a low content of rare earth metals. A low content of rare earth metals means less than or equal to 1.0 mass% of rare earth oxide on the zeolite portion of the catalyst. Modifying additives to the catalyst may be added to the catalyst during operation. Medium pore molecular sieves, such as MFI zeolite types with openings of 0.7 nm or less, can be mixed with molecular sieves having large pores to increase light olefin production. In some cases, only molecular sieves with an intermediate pore size can be used if the feed to the elevator reactor is the overhead obtained from the FCC process, such as a naphtha stream.

The elevator reactor 20 can operate at a catalyst-oil ratio in the range from 4 to 12, preferably from 4 to 10. The amount of inert gas supplied to the elevator reactor 20 can be from 1 to 15 wt.%, Based on hydrocarbon feed, preferably from 4 to 12 wt.%. Before contacting the catalyst, the hydrocarbon feed may have a temperature in the range of 149 to 427 ° C (300 to 800 ° F), preferably in the range of 204 to 288 ° C (400 to 550 ° F). The elevator reactor 20 may operate at a temperature in the range of 427 to 649 ° C. (800 to 1200 ° F), preferably in the range of 482 to 593 ° C. (900 to 1100 ° F). The pressure in the riser reactor 20 may range from 69 to 241 kPa (gauge) (10 to 35 lb / ^in2), preferably 103 kPa (gauge) (15 lb / ^in2).

Preferred embodiments of the present invention are disclosed herein, including the best options known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are merely examples, and should not be construed as limiting the scope of the invention.

It is believed that a specialist in the art without further elaboration and research, using the above description of the invention, can use the present invention in its fullest extent. The preceding preferred specific embodiments should be understood, therefore, only as illustrative, not generally limiting in any way the rest of the description.

In the above description, all temperatures are given in degrees Celsius, and all fractions and percentages are by weight, unless otherwise indicated.

From the above description, a person skilled in the art can easily establish the essential features of the present invention and, without going beyond the scope and essence of the invention, can make various changes and modifications of the invention in order to adapt it to various conditions and applications.

Claims (10)

1. A catalyst regenerator comprising
a regenerator housing having an inlet for a catalyst and a combustion gas, an outlet for a regenerated catalyst, an outlet for discharging the catalyst to a cooler, and an outlet for exhaust gas;
a catalyst cooler having an inlet for a hot catalyst in communication with an outlet of said regenerator body serving to divert the catalyst to a cooler, a gas distributor, an air outlet, an outlet for a cooled catalyst, and a plurality of heat exchange tubes located therein for conveying a heat carrier; and
an air pipe communicating said air hole with said regenerator body. 2. The catalyst regenerator according to claim 1, containing in the specified catalyst cooler the head part between the specified inlet for the hot catalyst and the specified air hole. 3. The catalyst regenerator according to claim 2, in which these heat transfer pipes are located below the specified head part. 4. The catalyst regenerator according to claim 1, wherein said regenerator housing comprises a combustion chamber and a separation chamber, and an outlet for discharging the catalyst to the cooler is located in the specified separation chamber. 5. The catalyst regenerator according to claim 4, in which the specified air pipe passes to the specified separation chamber. 6. The catalyst regenerator according to claim 4, in which the specified air pipe passes to the specified combustion chamber. 7. A method of regenerating a catalyst, comprising
burning coke from the catalyst in the regenerator body;
transporting the hot catalyst from said regenerator body through the inlet for the hot catalyst to the catalyst cooler;
cooling the hot catalyst coming from the regenerator body in said catalyst cooler;
catalyst fluidization with air in said catalyst cooler;
discharging the cooled catalyst from said catalyst cooler; and
venting air from said catalyst cooler to said regenerator housing separately from said cooled catalyst and said hot catalyst inlet. 8. The method according to claim 7, in which the specified housing of the regenerator contains a combustion chamber and a separation chamber, and the specified hot catalyst is removed from the specified separation chamber for transportation to the specified inlet for the hot catalyst, and air is vented to the specified separation chamber. 9. The method according to claim 7, in which the specified housing of the regenerator comprises a combustion chamber and a separation chamber, and said hot catalyst is discharged from said separation chamber for transporting to said inlet for a hot catalyst, and air is discharged into said combustion chamber. 10. The method according to claim 9, in which the specified exhaust air is directed up and then down after removal from the specified air holes and before entering the combustion chamber.

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