CN101501164A - Ancillary cracking of paraffinic naphtha in conjunction with FCC unit operations - Google Patents

Abstract

The production of light hydrocarbons consisting of ethylene, propylene, butylenes, and of gasoline is enhanced by introducing a virgin paraffinic naphtha feedstream derived from an external source into an ancillary downflow reactor that utilizes the same catalyst composition as an adjacent FCC unit for cracking the naphtha and withdrawing the desired lighter hydrocarbon reaction product stream from, the downflow reactor and regenerating the catalyst in the same regeneration vessel that is used to regenerate the spent catalyst from the FCC unit. The efficiency of the recovery of the desired lighter olefinic hydrocarbons is maximized by limiting the feedstream to the downflow reactor to paraffinic naphtha that can be processed under relatively harsher conditions, while minimizing production of undesired by-products and reducing the formation of coke on the catalyst.

Description

Auxiliary cracking with FCC unit operation paraffinic naphtha together

Technical field

The present invention relates to fluid catalytic cracking process operation together the raising light hydrocarbon such as the output of ethene, propylene and butylene and gasoline.

Background technology

Propylene is the second important petrochemical material structural unit that is only second to ethene.Propylene is as from the byproduct acquisition that is used to produce the steam cracking of ethene and is used to produce the refinery fluid catalytic cracking process of gasoline traditionally.The protrusion of the needs of propylene increases and has begun to have surpassed ethene, makes existing technology can not satisfy the needs of propylene from now on.In order to satisfy the market requirement of propylene, may utilize catalysis paraffinic naphtha cracking technology.

The catalytic cracking of olefinic naphtha is well-known and uses in the FCC apparatus of the various raw materials of processing of all types at present.The pressure naphtha of recycling, in having the FCC riser reactor of basic material, easily be converted into propylene from the olefinic naphtha of FCC, viscosity breaking plant or coker.The gasoline of being produced by recycling is being high aspect octane and the aromatic content.The FCC technology of prior art all can have the straight run of cracking lightweight effectively (＂ LSR ＂) petroleum naphtha under the situation about significantly changing.

Fluid catalytic cracking, or FCC are the well-known and widely used technology that is used for heavy hydrocarbon, gas oil and residual oil are converted into the light hydrocarbon fraction.In general, the technology that is used for the crackene raw material depends on and the contacting of the fluidisation catalysed particulate that maintains suitable temperature and the heating of the reaction zone of pressure.When heavy feedstocks contact thermocatalyst and cracking were lighter products, carbonaceous sediment was commonly referred to as coke, forms and make its inactivation on catalyzer.Inactivation or used catalyst separate with crackate, strip removable hydrocarbon and be passed into revivifier, wherein coke is burnt from catalyzer and is produced the catalyzer of regenerating basically in the presence of air.Products of combustion is removed as stack gas from revivifier.The catalyzer of the regeneration of heating is cycled back to the reaction zone in the FCC apparatus then.The general introduction of FCC technology is provided at USP 5,372, and in 704, its whole disclosures are incorporated herein by reference.

Advised that the whole bag of tricks and device are used to improve or increase the output from the specific product logistics of FCC apparatus.Sometimes, provide auxiliary reactor and other to handle container and handled special fraction or reaction product stream.In some cases, a plurality of reactors are provided, each has different chargings, so that obtain the product logistics of special expectation.

For example, USP 4,090,949 have described a kind of method that improves olefinic quality of gasoline inferior, use two riser reactors, one of them receives typical gas feed logistics, and second is used for the feed stream that cracking mainly is made up of the olefinic gasoline of poor quality.Temperature of reactor is that the ratio of 450 ℉-900 ℉ and catalyzer-olefinic gasoline is 1-40, and the residence time is 1-30 second.

At USP 3,856, a kind of technology of using a plurality of zones of cracking in fluidized-bed or riser reactor in parallel is disclosed in 659.In aspect of this integrated process, mix with the pressure naphtha (olefinic) of recycling and be fed to one of riser reactor from the paraffinic naphtha charging of crude unit.Typical service temperature is 900 ℉-1,300 ℉, and catalystoil ratio is 3-20, and the residence time is 1-10 second.

At USP 4,297, disclose in 203 a kind of at the transfer lime that prolongs, or in the lifter, use independently a plurality of have upward to the technology of fluidized reactor.From the cracked naphtha feedstock of first riser reactor be recovered and, with another hydrocarbon feed stream, be cycled back to second lifter.Temperature of reactor is in the previous example.

At USP 4,830, a kind of method that is used for upgrading or cracking virgin naphtha is disclosed in 728, use the single catalyst of y-type zeolite, the perhaps combination of Y zeolite ZSM-5.In this technology, ethene mixes with virgin naphtha in riser reactor.This technology has been mentioned the quality that improves virgin naphtha, described virgin naphtha and round-robin cracking material mixing and be injected in the independent upflowing riser reactor.Obviously, the purpose of this technology is to improve the quality of petroleum naphtha in two riser reaction zone, wherein catalytic gas oil and/or residual oil in first riser tube, catalytic cracking ethene and in second riser tube and in the dense fluidized reactor by the petroleum naphtha recycle of catalytic cracking and/or other petroleum naphtha.

At USP 5,372, a kind of method has been described in 704, it is using used catalyst so that with FCC petroleum naphtha or the limited lighter products that is converted into of other thermogenetic olefinic naphtha in cracking case again, and wherein the octane value of product petroleum naphtha increases.The operational condition of this technology is comparatively gentle, and temperature is 800 ℉-1,100 ℉, and the residence time is 1-100 second.

The disclosure of above-mentioned patent and the review of other prior art resource are failed to disclose a kind of technology, in it and FCC apparatus cracking direct-distilled (virgin) paraffinic naphtha feed stream together, mainly producing the light olefin of forming by ethene, propylene and butylene, and gasoline.

Therefore the purpose of this invention is to provide a kind of technology, wherein, as fraction from external source such as crude oil atmospheric distillation tower, topping unit, as the direct-distilled paraffinic naphtha feed stream that takes out from the by-product stream of hydrotreater or hydroeracking unit, perhaps, provided the lightweight reaction product stream by further cracking from other higher alkane hydrocarbon system naphtha stream of extraction process.

Further target of the present invention provides such technology, and described technology can effectively utilize the identical catalyzer that is used for FCC apparatus and turn round.

Another target of the present invention provides a kind of novel process, it is used for effectively the cracking of paraffinic naphtha raw material to produce the light hydrocarbon product logistics of being made up of ethene, propylene, butylene and gasoline, described reaction product stream can be reclaimed individually and further fractionation perhaps combine and be used for further fractionation so that reclaim independent component with effluent logistics from FCC apparatus.

Term " paraffinic naphtha charging " should be understood to include any hydrocarbon charging, and extremely up to about 450 ℉, the paraffinic components that it comprises 40wt%-80wt% has few olefin component to its boiling spread at pentane (C5) hydrocarbon.Remaining component will be naphthenic hydrocarbon, aromatic substance and alkene, the order of successively decreasing with composition.This paraffinic naphtha charging is usually from crude oil or other atmospheric fractional tower, but can also derive from the technology that other production contains the hydrocarbon of paraffinic hydrocarbons.For example, known hydroprocessing technique will produce paraffinic hydrocarbons from the feed stream of olefinic and aromatics type in refining and petrochemical industry industry, and it can be used in the enforcement of the present invention.Term " paraffinic naphtha " also will be understood to include lightweight straight run (LSR) petroleum naphtha, or virgin naphtha, the sort of as what from crude unit, obtain, and will comprise higher alkane hydrocarbon system naphtha feed logistics from extraction process, it all is known in the art.

Summary of the invention

Above-mentioned target and further advantage obtain by improvement technology of the present invention and device, wherein add the down-flow fluidization catalyticreactor as auxiliary reactor to existing FCC technique unit operation.Auxiliary downflow reactor system, used with FCC apparatus in the used identical heat catalyzer of regenerating.Catalyzer of regenerating and the direct-distilled paraffinic naphtha feed stream that is derived from the source that is independent of FCC apparatus be introduced into and the top of the downflow reactor on reaction zone in mix fully.

Mixture is by reaction zone, and the residence time is 0.1 second-5 seconds, and preferably 0.2 second-2 seconds, wherein the reaction zone service temperature was 900 ℉-1,200 ℉.In reaction zone, the ratio of catalyzer and petroleum naphtha also is called agent-oil ratio, is 10wt%-80wt%, and preferred operating restraint is 20wt%-50wt%.The mensuration of agent-oil ratio is that index and its mensuration of operating severity is well-known in the art.

The introducing by the single feed stream of direct-distilled paraffinic naphtha feed composition is depended in the valid function of this technology.The agent-oil ratio of the lower residence time and higher 20-50wt% is specific for the paraffinic naphtha feed stream.Other hydrocarbon is introduced the yield that will influence the light hydrocarbon reaction product of expectation in the feed stream of auxiliary downflow reactor unfriendly.

Downflow reactor provides some advantages, comprises final product and other component of relatively easy separation expectation.

Improvement technology of the present invention can be used with the prior art FCC apparatus, and no matter they use upflowing or the riser cracking of downflow system reaction process or the light hydrocarbon that bed cracking is catalytically conveted to petroleum naphtha expectation.

Any existing FCC catalyzer can be used to implement improvement technology of the present invention.Typical FCC catalyzer has or does not have catalyst additive, is applicable to this process modification.

Description of drawings

With reference to the accompanying drawings apparatus and method of the present invention will be described in more detail, wherein:

Fig. 1 is the typical FCC apparatus of prior art and the rough schematic view of technology; With

Fig. 2 is the rough schematic view of device of the present invention and implementation of processes scheme.

Embodiment

As noted above, method and apparatus of the present invention can use with the known FCC process unit of many prior aries.With reference to figure 1, diagram has been described typical prior art FCC technology.Reactor vessel (10) receives hydrocarbon, or oil, raw material (12), and it is allowed to enter the lower end of riser reactor (14), wherein it and catalyst mix fresh and/or that regenerated, the latter carries by pipeline (22).Be this rough schematic view and illustrative purposes, do not comprise the well-known many valves of normally used and those skilled in the art, temperature sensor, electronic regulator etc.

In this successive processes, the mixture of catalyzer and FCC reactor feed logistics upwards enters reaction zone by riser tube, wherein temperature, pressure and the residence time also be controlled in the common scope and with the processing property of one or more catalyzer that are used for this technology, the structure of device, type and characteristic and other various parameter correlations of raw material, these are that those skilled in the art are well-known and do not constitute part of the present invention.Reaction product is taken out by pipeline (16), is used for reclaiming and/or further handling at refinery.

Used catalyst from FCC apparatus takes out via transfer lime (18), is used to be transported to the bottom of revivifier (20), and described revivifier (20) is positioned at the most expediently relatively closely near FCC apparatus (10).The used catalyst that enters by transfer lime (18) touches the air logistics that enters by pipeline (24) at least, is used for the Controlled burning of any cumulative coke.Via pipeline (26), from revivifier, remove stack gas, improve the temperature of the catalyzer of regenerating, thereby provide heat for the heat absorption cracking reaction in the reactor vessel (10).

Referring to Fig. 2, now method of the present invention will be described.Should be understood that reactor (10) and revivifier (20) comprise with those total parts that combine Fig. 1 description and it is described and function will no longer be repeated.New device feature of describing among Fig. 2 and working method relate to downflow reactor (30), and it receives the catalyzer of regenerating via transfer lime (28) hot joining, and it is introduced into the top of container (30).Feeding line (32) will be from removing that FCC apparatus is introduced with the paraffinic naphtha feed stream of external source in case with the catalyst mix of the regeneration of coming in from revivifier (20).Petroleum naphtha and mixture of catalysts enter reaction zone (34), and it is maintained at the temperature of 900 ℉-1,200 ℉.The ratio of catalyzer and petroleum naphtha is 20wt%-50wt%.The residence time of mixture in reaction zone is about 0.2 second-Yue 2 seconds.

Though various catalyzer can be used in the described technology, should be understood that the identical catalyzer that is used for main FCC apparatus also is used to the catalytic cracking of the paraffinic naphtha feed stream in downflow reactor (30).In the embodiment of this invention, preferably, use the y-type zeolite catalyzer individually or with the ZSM-5 catalyzer with combining.As skilled in the art will understand, any that catalyst additive can also be in these systems uses.The selection of catalyst system does not constitute part of the present invention.

Continuation is reclaimed the lightweight reaction product stream with reference to figure 2 by pipeline (34).The method according to this invention comprises ethene, propylene, butylene, gasoline and is removed and can reclaims individually in the recovery zone (not shown) of separating or combine with reaction product stream from FCC apparatus from the light hydrocarbon reaction product stream of any other by product of cracking reaction and is used for further fractionation and last recovery.

Stripped vapor enters by pipeline (36), disperses any removable hydrocarbon from used catalyst.These gases discharge and are introduced into the top of stripping tower container (37) from downflow reactor (30), these bonded gases wherein, or steam, leave the stripping tower container so that carry out the product recovery by cyclone separator (39) and by pipeline (34) according to methods known in the art.

Used catalyst from downflow reactor (30) is discharged by transfer lime (40), and enter dropper (dip tube), or ascending manner riser tube, (29) lower end, described dropper (dip tube), or the ascending manner riser tube, extend from the bottom of improved catalyst regenerator (20) (29).

In this embodiment, via forced air pipeline (25), at the end of dropper or ascending manner riser tube (29), air is introduced under the used catalyst transfer lime (40).The more detailed description of the function of auxiliary downflow reactor (30) hereinafter is provided.

The selection of the structure and material of downflow reactor (30), and specific processing property and parameter will depend on the certain quality and the flow velocity of the paraffinic naphtha charging of introducing at feeding line (32), this will depend on the source of raw material again.Hereinafter also set forth more detailed operational condition.

Should will be appreciated that the present invention forgives widely and install the processing generation together of PetroChina Company Limited.'s raw material mainly by light olefin ethene, propylene and butylene in fluid catalytic cracking (FCC), the method of the product logistics of forming with gasoline, described fluid catalytic cracking (FCC) device comprises the catalyzer of the composition of defined, FCC and relevant downflow reactor catalyst charge, it is by the used catalyst regenerated, said method comprising the steps of:

A., independent paraffinic naphtha feed stream is provided and it is imported the top of the downflow reactor of close FCC apparatus;

The catalyzer of regeneration that b. will be used for the same type of FCC apparatus is introduced downflow reactor and is used for mixing with the paraffinic naphtha feed stream, and the ratio of catalyzer and feed stream is 10wt%-80wt%;

C. make catalyzer and paraffinic naphtha mixture by the reaction zone in downflow system (downstream) reactor, described reaction zone is maintained at the temperature of 900 ℉-1,200 ℉, and the residence time is 0.1 second-5 seconds, thus pressure naphtha;

D. separate reaction product stream and the used catalyst that contains light olefin and gasoline;

E. reclaim reaction product stream; With

F. make the used catalyst from downflow reactor lead to independent revivifier, the used catalyst that described revivifier also comprises from FCC apparatus is used for regeneration and is circulated back to FCC apparatus and downflow reactor.

Continuation is with reference to figure 2, the catalyzer of the regeneration of the heat of about 1250 ℉-1500 ℉ by conventional methods, for example, pipeline or conduit (28) by downward guiding, be commonly referred to as transfer lime or vertical tube, be delivered to the withdrawal well (withdrawal well) or the hopper (hopper) (31) at the downflow reactor top on the reaction zone (33) from the regenerator vessel (20) of FCC technology, it is stable to make that at this thermocatalyst flows, so that import the mixing zone or the feed injection part of reaction zone (33) equably.Voltage stabilizing pipeline (38) connects the top of withdrawal well (withdrawal well) (31) to existing revivifier (20).

Feed naphtha is injected into the mixing zone by feed injection nozzle (32a), and described feed injection nozzle (32a) is placed near the introducing point that the catalyzer of regenerating enters downflow reactor (30).These a plurality of injection nozzles (32a) cause catalyzer and oil to mix fully and equably.In case paraffinic naphtha raw material contact thermocatalyst, cracking reaction takes place.The reactive vapors of hydrocarbon cracking product and unreacted naphtha feed and catalyst mixture promptly flows through the rest part of downflow reactor and enters in reactor bottom sharp separation district (35) partly.According to the residence time of the mixture in device known in the art and the time variable control reaction zone.

If necessary,, abut against before the separator, in bottom, for naphtha feed, circulation cracked petroleum naphtha or other light olefin provide quenching injection (50) near reaction zone (33) for temperature control.This quenching injection promptly reduces or has stopped cracking reaction and can be used to control cracking severity and the craft flexibility that increases is provided.

Temperature of reaction, it is the temperature out of downflow reactor, control by opening and closing catalyzer slide valve (not shown), described catalyzer slide valve has been controlled from withdrawal well (withdrawal well) (31) and has been entered catalyzer mobile of the regeneration of mixing zone.The required heat of cracking reaction of heat absorption is to be given by the catalyst supply of regenerating.The flow velocity of catalyzer of the regeneration by changing heat, operating severity or cracking conditions can be controlled to produce the light olefin and the gasoline of expectation yield.

Quick disconnector (35) is placed in the epimere of the tun that is called as catalyst vapor stripper (37) with the terminal portions of downflow reactor (30).Quick disconnector directly imports reactive vapors and catalyzer in the top section of stripping tower container (37).

The logistics of reactor steam moves upward to the stripping tower from the quick disconnector outlet, with from the stripped hydrocarbon product steam of the catalyst stripping section of this container with stripping gas combines and by conventional tripping device such as cyclonic separator (39), it further separates any granules of catalyst of carrying secretly and steam.Be captured in the bed that the bottom that imports to stripping tower container (37) by cyclone dip-leg from the catalyzer of separator in the cyclonic separator is used for being drained into catalyzer, reclaim in the quick disconnector of described catalyzer from stripping stage.

At the steam that merges by cyclonic separator and after leaving the stripping tower container, the product recovery zone that pipeline by being commonly called reactor vapor line (34) or conduit import to the known routine of FCC technical field.

From the catalyst stream of quick disconnector and the cyclone dip-leg hypomere to stripping tower reactor vessel (37), described stripping tower reactor vessel (37) comprises the catalyst stripping section, and suitable stripping gas is introduced wherein by logistics pipeline (36) as steam.Stripping stage has several baffle plates or structured packing (not shown), and the catalyzer adverse current that flows downward thereon is by the mobile stripping gas.Mobile stripping gas upwards, it is steam normally, be used for " stripping " or remove any other be retained in catalyst pores or granules of catalyst between hydrocarbon.

Steam stripped catalyzer is carried by combustion air stream (25) by ascending manner riser tube (29), described ascending manner riser tube (29) ends in the existing revivifier (20) in the typical FCC technology, thereby burn any coke, it is the by product of petroleum naphtha cracking process.In revivifier, the heat that is produced by the combustion by-products coke is transferred to catalyzer, and described by-product coke is produced in first reaction zone (10 and 14) of typical FCC technology and by the petroleum naphtha cracking in the district (33) in downflow reactor (30) by the cracking heavy hydrocarbon.

Regenerator vessel (20) can be any routine previously known design and can use with improvement technology of the present invention and downflow system reaction zone.Revivifier-pipe reactor (28) or the placement of catalyst transport that is used for the regeneration of revivifier should be such, make its stable and successive of guaranteeing the catalyzer of a large amount of regeneration flow, this is that the design maximum that satisfies downflow reactor requires needed.

Catalyzer for technology of the present invention requires and can come together to determine with the catalyzer of any FCC of being generally used for technology, and for example additive and any other of cracking additive, production light olefin are generally used for the catalytic additive of FCC technology at the bottom of zeolite, silica-alumina, CO burning promotion additive, the tower.Preferred cracking zeolite in FCC technology is Y, REY, USY and RE-USY type zeolite.For improving petroleum naphtha cracked possibility, being generally used for FCC technology is ZSM-5 zeolite crystal or other five yuan of supersiliceous zeolite type catalyst structures with the preferred shape selective catalysis additive of producing light olefin and raising FCC gasoline octane rating.Cracking catalyst zeolite in this ZSM-5 additive and the conventional FCC catalyzer and base-material structure are mixed and are preferably used in the inventive method so that maximization and optimization cracking paraffinic naphtha in downflow reactor.

As special advantage improved of the present invention the quantity of the coke that produces by these cracking reactions to the existing FCC technology that is used for typical FCC heavy hydrocarbon feeds.In the petroleum naphtha cracking, influence the operation efficiency of whole device unfriendly owing to the limited quantity of the coke that during cracking reaction, produces.The quantity not sufficient of the coke that is produced is to produce enough heats so that the paraffinic naphtha cracking reaction is taken place in downflow reactor during the catalyst regeneration.Comparatively speaking, the coke that is produced during heavy oil or gas oil cracking in typical FCC technology is greater than the desired value that institute's heat requirement is provided for downflow reactor.In the method for the invention, this heat in container (20), during reclaiming process, by mixing the used catalyst from two kinds of sources, is delivered to downflow reactor by the catalyzer of regenerating from revivifier.

As the improvement of the existing FCC technology that is used for handling simultaneously paraffinic naphtha, further advantage of the present invention is that product can reclaim in the recovery zone of conventional device.Unconverted paraffinic naphtha can circulate in FCC technology to be produced additional light olefin by the cracking olefinic naphtha or as the blending stock in the gasoline product with olefinic naphtha.Described technology has such advantage, provides the independent recovery of petroleum naphtha from each reactor so that further independent downstream processing, and with two kinds of logistics in conjunction with so that be partly recirculated to FCC apparatus or carry out the alternatives that gasoline is in harmonious proportion.

Embodiment

Use small-sized pilot plant to measure and be used for from the operational condition of the product yield of the typical paraffinic naphtha raw material acquisition of cracking expectation.The cracking conditions in the downflow reactor is represented in use pilot plant unit.

In following examples, use two kinds of catalyst systems to prove that the cracking paraffinic naphtha is to produce the potential of selectivity of light olefin hydrocarbon.A kind of catalyzer is the USY type zeolite catalyst that typically low rare earth, low hydrogen transmit, and it is commercially available getting.Second kind of catalyst system is the same commercially available USY zeolitic cracking catalyst that gets, and blending has the cracking catalysis additive of selecting shape ZSM-5 zeolite type.

Following table has been summed up by change the influence that temperature of reactor changes cracking severity in the pilot scale unit of two catalyst systems.

As used in the table, term " selectivity " is defined as the ratio of the quantity of specific components and all gas, for example propylene/all gas.

Should be understood that above-mentioned embodiment is to illustrate the present invention, and those skilled in the art can carry out various changes, it will fall into by in the determined scope of the present invention of following claim.

Claims (15)

1. a raising is derived from the method for the paraffinic naphtha feed stream of crude unit to the conversion of the light hydrocarbon product logistics of being made up of ethene, propylene, butylene and gasoline, and this method comprises:

A. the independent feed stream of paraffinic naphtha is imported to the top of downflow reactor, described downflow reactor comprises catalyzer fresh or that regenerated, have and the catalyzer same composition that is used for FCC apparatus, described FCC apparatus and downflow reactor are related;

B. operating downflow reactor, feed stream is 0.1 second-5 seconds in the residence time of reaction zone, and service temperature is 900 ℉-1,200 ℉, catalyzer and feed stream ratio are 10wt%-80wt%, thereby produce the light hydrocarbon reaction product by cracking paraffinic naphtha feed stream;

C. in the downstream of reaction zone, be separated in the light hydrocarbon reaction product stream and the used catalyst that produce in the downflow reactor cracking process; With

D. reclaim the light hydrocarbon reaction product stream.

2. the process of claim 1 wherein that operating downflow reactor, the feed stream residence time are 0.2 second-2 seconds.

3. the process of claim 1 wherein that catalyzer and feed stream ratio are 20wt%-50wt%.

4. the process of claim 1 wherein that light hydrocarbon reaction product stream from the recovery of downflow reactor is subjected to fractionation and handles.

5. the process of claim 1 wherein to combine with effluent logistics and be used for fractionation and handle from FCC apparatus from the light hydrocarbon reaction product stream of the recovery of downflow reactor.

6. the method for claim 1, it comprise in conjunction with and mix from the used catalyst of downflow reactor with from the used catalyst of FCC apparatus and with institute's bonded used catalyst regeneration so that in FCC apparatus and downflow reactor, reuse.

7. the method for claim 6, it is operate continuously.

8. the process of claim 1 wherein by cyclonic separator technology separate hydrocarbons reaction product stream and used catalyst.

9. the method for claim 1, it is included under the reaction zone and quench fluid is applied to reaction product and catalyzer.

10. the method for claim 1, it is included in the downstream stripping used catalyst of reaction zone.

11. one kind and in the processing generation together of fluid catalytic cracking (FCC) device PetroChina Company Limited. raw material mainly by light olefin ethene, propylene and butylene, the method of the product logistics of forming with gasoline, described fluid catalytic cracking (FCC) device comprises the catalyzer of the composition of defined, the FCC catalyst charge, it is by the used catalyst regenerated, and this method comprises:

A. independent paraffinic naphtha feed stream is introduced top near the downflow reactor of FCC apparatus;

The catalyzer of regeneration that b. will be used for the same type of FCC apparatus is introduced downflow reactor and is used for mixing with the paraffinic naphtha feed stream, and the ratio of catalyzer and feed stream is 10wt%-80wt%;

C. make catalyzer and paraffinic naphtha mixture by the reaction zone in the downflow reactor, described reaction zone is maintained at the temperature of 900 ℉-1,200 ℉, and the residence time is 0.1 second-5 seconds;

D. the reaction product stream of the gained of separation of lighter alkene and gasoline and used catalyst;

E. reclaim reaction product stream; With

F. make the used catalyst from downflow reactor lead to independent revivifier, the used catalyst that described revivifier also comprises from FCC apparatus is used for regeneration.

12. the method for claim 11, operating downflow reactor wherein, the feed stream residence time is 0.2 second-2 seconds.

13. the method for claim 11, wherein catalyzer and feed stream ratio are 20wt%-50wt%.

14. the method for claim 11 wherein combines with effluent logistics from FCC apparatus from the reaction product stream of the recovery of downflow reactor and is used for fractionation and handles.

15. the method for claim 11 wherein is subjected to fractionation from the reaction product stream of the recovery of downflow reactor and handles.

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