AU777436B2 - A fluidized catalytic cracking (FCC) process - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventors: INDIAN OIL CORPORATION LIMITED Marri Rama RAO Vutukuru Lakshminarasimha MURTHY Sanjeev SINGH Asit Kumar DAS Sobhan GHOSH Debasis BHATTACHARYYA Satish MAKHIJA Sukumar MANDAL CULLEN CO., Patent Trade Mark Attorneys, 239 George Street, Brisbane, Qld. 4000, Australia.

A FLUIDIZED CATALYTIC CRACKING (FCC) PROCESS a so a

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*r S *1555 00 0@ 9 0 0@0@ Address for Service: Invention Title: The following statement is a full description of this invention, including the best method of performing it known to us: FIELD gF TJjE INVENTION: This invention relates to S fLtidi zed catalytic cracking (FCC) Process +or- converting heavy Vacuum go% oil and residual Oil fractions into lighter products and to an apparatus theref or B~ACKGROUND OF THE INVENTION: Fluid Catalytic Cracking (FCC) is one of the important processes used in petroleum refineries 4orconverting heavy vacuum gas oil into lighter Pr0duCtS namely gasoline, diesel and liquified petroleum gas (L-PS) Processing o+ heavy residues e.g. atmcospheric and vacuum bottoms are increasingly being practiced in the FCC Unit for enhanced conversion of residue. Heavy residues contain higher amount of c-onradson carbon residue CCR, poisonous metals e.g. sodium, nicifel, vanadium anid basic nitrogen compounds etc., all v+ which have significant impact on the performance of FC.: uit the stability o+ its catalyst.

The high 12CR o+ the feed tends to form coke on the catalyst. surface which in turn brings down its ectivity and selectivity. Moreover, the higher deposit of coke 4on the catalyst. increases the regeu #erator 2.

temperat.tre and therefore catalyst/oil ratio ,educesi for* heat balanced FCC unit. The FCC Cntalys-t cmin toerate a max:imumn temperattre of upto 750 0 C, Which limits the CCR of feed thiet can be pror~ssed in FCC. At Present, FCA' wi th tvio stage r-49enerator and cata 1 yst coole?54 can handle tip to Il wt'. feed CCR eironrjwicet ly.

Nickel vanadium an~d sodiuim are nlso available in quantity in the residial feed. ihe pr.'soning effects of these constituents are well1 knowon 18in the FCC art. Ina the past, there ha.ve beeni some effor-ts to passivate the damaging ef-fects of nickel and vanadium an the catalyst. These efforts have resulted only with some sticcess in the passivaticw' of nickel.

Thus, by the I'riown methods, it is pre-sently possible to handle up to soine 30 ppm of nicIhel on the feed and upto 10,000 PPM niclfel oil the equilIi br iutm catal yst.

~SimnilIarlIy, wi th the knowi- processes, vanadiurn tip to only ppirt aii feed asid 500 ppm oil the equil ibritmt ctalyst can be handled ecoinomically, These above limit.s provide a serious probl em of resi due processing capabil ity of FCC tinit. As stsch, httre quantity of metal laden equilibrium catalyst are withdrawn frpm reCsidue FCC Wiit to keep the circulatingQ catalyst metal level within the tolerable limit. (is regards~ :te 1'asi I: iti rogefi compcitrnds, sujtabl~v pasisivatin tech-nology if' yet to be f ottnd.

11% add it i oi to the deveJ r~pitsen~ of D passivation techrwci gies, there have beet some~ inmpctr.ant.

design cliainges made for effici ert resi dtue prcw-s-sing.

One sitqcfh des-49n change is the Lwo stnge refveiieratiofl instead of a siiigle s~tage regeni-rat ion. US Pai ent 4064039 descri bes the a ages of t VoC -Iage regenera~tor and it.z, +F.exibility to handle additional feed CC[ withotit. reqtiiring cot klyst c ol er. However, even mtii: the two stagje regenerator of US~ Patent no.4064030, her-e i~s a limnitatinn to jnr~~feed

CCR

above 4.5 et10 veIaditun above I~-~ppm rill +ee'd 1V 1. has be4:nr oggented in the art to vise a "~eparabJ e rji xtitrv otf cata yst 'arnd i itert Sol id Par ticl es: for procecl rig of resi d. fhun, 111- Patent. Nos.4895637 an-d 51107'15 sttgge-s a physic~ally separ-abir? iuxi:ttre of FCC cataly~t an~rd varwadium additive having stifficient differences in their setting velocities so eks to cover a segregationf of the twro types uf+ particles in a s ing Ie stage r egenerator. Ilitwigh vloch a process is sinjple, there are several practical disadvantages whiich limit its resid hAndling capability, na~mely 4 0i) tile r-egelierat-or- is kept irk the dense phase wh-ere t he avrage super- f i c i alI vel oc j y i c. about 0i.7 meter/secand. At si ch a ve I c i ky lIevel ,the cfftal yst p arti ClIes stil 1 possess considerable gravi tational ptA] Moreover,there is siJ+ i ci ent tur-btideice And mix:i ng int' he bet! Which I eads t a poor segregation efficiency.

(ii) It is, known in the FCC art that varfadium Js hiilhly mobile i~n the regenerator atmosphere, end iethat in the -single stage regen rator, the vanadiuwf atoy escape from tile -dditive to the catalysparticle. 1Ibis i:efeats the basic puirl. -e catalys' /additive segregation.

iii) At locwer- velocity of 'Ietisf: bed req i in, larger partIcles -tff ianad I+ addi ti ye may iut f Wtidize Srcrne ''thiese i ssites have been addr essed by ::Hadda Ial. r% US3 patent 46*75994 wihere conmbustor type tw eg egeneratur- i5 proposed. Hi gh velOci ty 2a combusticin air is used to li-ft the catalyst particles f r-cim the coinbUStOr *However, the mobil e vanadi urn vapor s ire all owed t% move to thie vii g temper attire regenerator thog lf t line alang with the catal yst t1iiC h May C atse cortsiderable dainage to ZeoiliteS in the ctalyst particles. In addition, the downcomer line f rom the r egener at or to the combustor may all ow the separated catalyst particle to again get mix~ed with the adiditive.

US Patent 4814068 discl:os-es 8 it! I t istage process with three sets o+ intermediate r-iser, U bend, mixring arnd flte gas system. StAE1 a sMyStefn iS ti 16 to separate large pore catalyst particle 4rom those havi ng intermediate pores. i he Particle sire of+ the coarse particle is also very high (50-7000 micran) to avoid the carry-over o+ coarse particles to the second stage regenerator Similar1y, LIS Patent 4892643 and 4767967, also take Alp separation o-f particles of two very *different sizes, one having 20-150 micron arid the othe~r 50-7,0i06 microns. The stripper section is made annular douible stage where by the diff+erence rof settinig velocity o34 the above two size range of part icles are erploi ted.

US paterit5 4695636 and! 4971766 disclose a process and apparatu5 +fir contacting residue feedstock 6 in the den-se bed krept at the riser- bottom before cuetting cracked by thle cuatniyst in the riser. However, the major problem is the proper atomization of feed in the dense bed with largp particles at lnv) velocity. In addition, the system waill be prone to more non selective thermal crncking in the dense bed below riser rest.0ting in higlier gas and coke make. Moreover, the feed CCR will also deposit on the catalyst and theref'ore, thie CCR reLated problems of residue are not. addressed.

lB OS ['atent. 4927522 di scl ose antither way of increasing Elie resi dence tiuwe of ZStl-5 additive iii the ri ser crr.A$.ioig pro~cess. Here the ri-ser is ma~de withi several enlarged regitans and separate feed entry locaitionis afl-.er- each eri arged secti on.

The inventions of US Patent No.5196172 and US Pat No.5Q59302, claim of FCC process and apparatuis employing a separable mixture of catalyet. anad sorbewiL part ic I e. Here the sorbent particles are smnaller i n size (30-90 microns) and the catalyst .particles are bigger in size (80-150 micron). 1he process employs selective varte): pocket classifier and hourizatital cyclorie type burner to -orifinuotvsi y separate the two types of parkicles.

:7 (IBJECTS 9j 1EI. itIVEN I 1014 A~rt object of this ireveniti ar is Pr'OPOse a f luidized Cracking Proces 'for- con'verting heav'y vacttum gas oil and residual oilI fractions into l ighter products and an apparatus theref or.

DESCRIPTION LIF IHE INVENTION According t~o this invention there i. provided a fluidized catalytic cracking apparatus comiprising a riser having a feed inlet for introduction' of the feed Lek stream containing heavy residual oil 4ractions with high concentrati ons of cr.wir adsori colre inetal s stich ats vanaditim, ni ckel and other poisons such as basic ni trc.gell, sai d ri ser- having a first imlet for introduction of high velocity steam, a second inlet. for- .15 introd~uction~ of the feed, a third inlet for- irttr-cdiiction of an adsorbent, a fourth inlet for introduiction of the regenerated cat~alyst, sai d ri ser extendi i-q irto E a stripper- for catising a separation of h ydr o. t-ban fraction from the spent catalyst and adsorbent, said :6stri-pper connected to a separator f o? C.aus3i ng a Separation 0 f the adsorbent, a burner in1- flow communication with said separator for- r-eceiving. the adsorbent, a regenerator in fl1ow communmicati on wi th said separator -f or regenerating the z U catalyILt separated in the separator, said burner h~aving ant outlet in flow commuicationi with the third irilet +-or introdocticoni of the adsorbent into said ri serl sai d regenerator having an oLutlet, in, flow communicationl with said fourth inlet. for introduction of said regenerated catalyst into said riser.

FUrther- according to this invention there i s provided a 4 luidized catalytir cracking process for C-0uiver-ti rig heavy VaCLLUn tIaS C' Il and res.idual oil 16 ractions into lighter- products comprising in +fi rst cmitact i n a heavy residue- feedstEv-ckI with art adsorbent so that the impuirities are deposited on the dor-beit. in the bottoot of a riser, al lowi lig the fe-dstoc:. arnd adsor-bent to contacT a catalyst so as to ca'ise a cracking reaction, the catalyst arid adsor-berit. beinrg separ ated -fr om the procdi .ct hydrc-tcarbons in a stripper, the mi xture of tcatel yst and adsorbent being t rdutred inoB separ-ator for causing a separation of the spent Catal yst arid adsorbenit, the spenit adsorbeit. beinrg introduced i nto a burner and the acti vated adsorbent recycled iinto said ri-3er, the spent catalysf. bei ng r-egener at ed int a regenerator and then intradiuced into said riser.

r9: TIhe present. 3nvenstion, provides fluidized catalytic cracking process and apparatus, t-shei-eir a.

heavy residtue feedstack is first coi-tacted with hot adsorbent particles at the riser- bottom in presence of lift steant. 'the CCR, metals and other imptirities of residue are first deposi ted on the adsor-bent particles in the bat tarn par t of the r iser. Subseq'tent I y, the adsorbent and cl eaned hydrocarbon mixture is~ contacted woith hat regenerated FCC catalyst. particles and the Is cracking reactions are acconqlished in the remainiung part of the riser. 'the catalyst and adsorbent particles are separated from the product hydracarbons, stripped using couinter ctirrent. stripping and allowed to flow into the catal yst separator device.

he improvement in the present invenstion also consi sts of separ ating the catalyst par tic les in the separator using steamI at relatively higher- Velocity but at moderately Jowver temperature, S1uc0 tha~t the adorbet p-ticle fom a dense bed and the catalyst particles Ore transported to the t op aof the regenerator. The separator lift steam is separated from the erisuing catal yst using cycl one and the catal yst after separation is regenerated using oxygen containing 180 gas and recycled to te said riser but. at a level higher than the cataklyst inlet. *the adsorbent particles are voithdrown from the separator bottom and fed Lo the burner where partial or complete remtovel of coi:E- is~ done using ox'ygeri containing gas and the decoked adisorbent, is renycled bad-. to the said riser bottom. Ini accordance i t h aft embodimlent. of Lhis invention, a purge outlIet is provided with the burner- to withdrew a net stream of adsorbent particularly when heavy 4eed with is high CCR is used. In such an embodimtent, calcined coke is the pr-ef erred adsorbent and the net coke withdrawon from the pturge outlet allows the residues with very high CCR to be processed without generating excess heat.

Such net coke stream may be used as fuel in gaSificaEtion ini~t or power plant or other- suitable alternate aisege.

The present invention also enivisag's a direct recycle of the adsorbent from t.he separator wi thout.

having any separate birner. Al so, a part of I.he regenerated catalyst may be circtilated to the separator O.O;Wto increase the tem"perature to som11e extent. In addition, both Lte adsorbent and Lte catalyst may be cooled before being recycled to the riser- tsi ng internal and external coolers if found economic.

.26 DESCgpATjONq OF 1HE~ INVE TION WITH

RFRNET

AQCCOMANY1!!N-Q 99R I NG3S Fig.1 show's a FCC apparatus of the prior art wit?' two stage regenerators, riser reactor wihsingle Stage arnnular stripper andi where the entry of solid particles iS at a single point in the riser,.

FIg.2 shows a FCC apparatus Of the present i nventi an hav ing a catalyst adsorhent separator device usi ng hligh velocity StesnI at lot-er tempr-rature and havitig single stage regenerator for (-atel yst, a burner for the adsorbenit, ri ser rePactinr with at I eas k two solid entry poinits, couni-er ciarrent.

st:ripper and other subsystems used it t:onventi anal FCC tjni k.

Ihe FCC regenierator vessel 1 of fig.1 receives spent catalyst from stripper 3. Comnbustionl air in the regenerator I is distributted at the bottom au-d catalyst dense phase 6 is maintained typically in partial combutstion conditions at which the coke on the catalyst is partially burnt off u~sing controlled amount air at moderate temperatuire. The flIuei gas of regenerator I is separated from the entrained rctatyst by Cyclonle 7 or a series of cyclones. The partially regen~eratedi catalyst is lifted from regei-feratar I to regeneratut' 2 at the top via lift line 9 by u1sing lift air 0B and pAl1g valve at 10. Secondary ai r- It is distr ib~~ted at the bottom of regenier-ator 2 FuChI that the dense bed 12 is mnaintained and the catalyst. is almost completely bttrnt off the cok~e below 0.1 vat%. The :12 x' a a is 15 00 0 0 0 0 0* 0 *00 000* 0* 0* 0*00 0 20 0@00 00*0 0 0 *0*0 0 0 0* regenerated catalyst: is withdrawn from line 13A having pressure equa I i z er- 13B and fed to the bottom of the riser 4 voith lift steam frcm inlet 14 and Ihydrocar-bofl feed injection 15 and the mixtutre of hydracar-bon and catalyst flow through the riser 16 followed by couni-tercurrent steam stripping in the stripper 3. the stripped and spenit catalyst flovis back to regenerto.r- I through pipe 1*7 for cantinuoius regeneration arid circtilatil.

The prcic~t hydrocarbon at thte r-iser end is separated from the catalyst using cyclone 18A, t8o, second stage reactor cycl one 21A, reactor plenum 22A arid directed to product +ractionator via transfer line 24.

The flue gas of regenerator 2 is separated -from the entrained catalyst by cyclone/series of cyclone 19A,19B arnd discharged thratgh outlet Fig.2 illtistrates the FCC apparatus of present iiiventi on wher e a separator 44 usinrg steavi i s employed to traitspar t the relatively Lighter at-if finer Catalyst particles to a regenerator vessel 46 after Separating from the above said steam using cyclon-e(s) and relatively hteevier and coarser catalyst particles from the dense bed (romn which the adsorbent is either directly recycled bacAh to the riser bottom or could be :133 partially or completely burrnt off the caloke in a coke burner before recycling to the riser bottom.

The apparatus of the present invention is illustrated in Fig.2. The mixture of spent catzalyst and adsorbent par-ti cles enter near the middle of a separator 44 vi a spent catal yst. standpipe 2 and a valve 3.

Stewsi ifftrodixced throtilt pipe 37 is Injected at: the bottom of SepArat.or 44 U3 help maintain a derose bed 41 of the relativel y heavier and coarser adsor bent particles. The superficial velocity in separator 44 is maintained suff-iciently so that. the relatively lighter and finer catalyst particles are transpov-ted to the top of a lift line 45 provided at the upper section of fe separ-ator 43. Lift line 45 preferably has a reduced .115 cross section than that of separator 43, and woherein .6 0 steam is injected at different elevation to facilitate an easy trafisport of the catalyst particles. t the top of lift line 45, cyclones 14A,14B are employed to see* *000separat the catal yst from steam, which srcoee 0 *00-*20througjh ovtlet 35 and may be recycled at different 0:sections of stipper 48 and riser reactor 43 stich at :14 25,26,40 or fnay be mixed with product hydrocarbons discharged f roon outlet 34, A~ purge outlet 383 is9 provided with burner 47 so' as to withdraw a n~et stream of adsorbent on continuous basis particularly when the residue feed being processed contains very high CCR.

The adsorbent in such an instance is preferably calcined colce particles, and a net stream of coke thus withdrawn helps to minimize the net heat generation in the system which allows the apparattus to operate with 4eed upto isvery high CUP level. In the instance where the feed CCR is very l ess, i t way not be necessary to have se-par ate adsorbent burner. I n suAch situation, t.he hot regenerated catal yst may be withdrawsn f ront thfe regenerator via line 42 and mix.ed with adsorbent at the 411.9separator. It may noted that: the separator temperature should be maintained with-in maximum 6,A 0 C: and preferably below 550 0 C to achieve the best catalyst thermal. and hydra thermal stability.

The catalyst flows through cyclone diplegs 15A,15P to 5regenerator 46 where air- is injected through in controlled or in e.:cess amount depending on the partial or* complete combustion of the coke on the catalyst as felt necessary. A~ dense bed of catalyst particles, is formed in regenerator 46 where the flue gas is separated using cyclone 19A,19B and allowed to flow via plenumn 29 to the flue gas arid power recovery sectinn. The.

regenerated catalyst is withdrawn through line 11 with pressure equalizer 22 anid recycled back to ri ser 43 at an intermediate r-iser elevation via pipe 23.

Th~e adsorbent particle are withdrawfi from separator 44 via downcomer 36 to adsorbent burner 47.

Oxygen containing gas is injected at the burner bottom Is via pipe 4 so that partial or total burning of the coke is achieved. The flue gas is separated in the burner cyclone 39., The burner is cooled by any suitable means for controlling the temperature upto a fna~xi1mumI of 750 0 C, but such cooling means may not be necessary since a separate coke stream is withdrawn continuiously frout outlet 38, especially When residue of very high CCR i s pr ocessed. The preferred adsorbent in such operation is calcined coke and therefore it. can be removed r a continuous basis from the apparatus which helps in maintaining the heat balance by minimizing the riet heat generation in tihe overall1 process. The adsorbent after- ::cokce burning is recyled from the bottom of burner- 47 Via standpipe 6 and slide valve 7 to the bottom of the riser.

316 1-ift niteam 25 is injected at the bottom of the r iser. Residu~e or poor- quality feed is injected at primfary feed noazzle 26 so that the CCR, metals and other pai scfts existing ini the residue feed are deposited onl the adsor-bent particles. The velocity is maintained in tile riser suiffi ciently above thle transpo'rt velDci ty of the adsorbent and catalyst to lift tile adsorbentcatal yst mi.(tture upwardly of r i er 43 and eventually at catalyst inlet 23 of riser 43, the W hydrocarbon which has been already vaporized anid cleaned by the adsorbent, come in contact with the regener-ated catal yst to accomplish tile actual catalytic cracking reactions and in the process make sufficient vapor to firther li ft the catal yst, ad-sor-bent nd hydrocarbon mixtiAre to the Lop of riser 43. An optionol feed niozzle 43 may be emprloyed to inject: relatively better quality :feeditacit or- to coritral the riser temper-atm.re profile by al 1owl rig to iii ject quench stream e.g. heavy naphths, heavy cycle Cti I etc. IThe hydrocarbon prodeict is froin the catalyst and adsorbent mixture at the top of Lhe riser- by employing known riser terminator, devices and preferentially short contact high efficiency *termi nator. 26A,28D. The product hydrocarbon vapor- :17 t discharged through outlet 34 is withdrawn from the top of the reactor after passing through line 30, cyclone 31 and plenum 33 and the spent catalyst. is stripped in stripper 35 using stripping steam 40 arnd spent catalyst/adsorbent mixture is withdrawn via standpipe 2 and slide valve 3 to separator 43 to mnake the solid circulation continuous. The distance between' the inlet o4 Fpp 6 and pipe 23 in riser- tuber 47, shouild be 20 to of the total riser length.

The major imnprovemients achieved in our invenbtion are summarized below: Mi The separaticin of catalyst and adsorbent is done at. low temper-atire in absence of any oxygen cont~aining gas. The contact time of the catalyst in the separator is very less, since the catalyst.

particles are immediately transported through thle lift line. Such unique separation significantly at. reduces the possibility of catalyst deactivation' :due to metals particularly vanadium. This also a 20 brings dovin the chances of vanaditum mobility -from the adsorbent to the catalyst phase.

ihe steant used in the separator h-lps. in achieving better stripping of the strippeble hydrocarbons carried by U[-2 catalyst ~n co- 29, current pnem~matic. trar-sport conditLion. Further, the steam arnd the ensuing !%ydrocarbofi are i-emoved f'-inth caal~-using cyclone T~.parators, a. as -efore thie catalyst is allowe'd to enter the asvs arer'eneratr. This un4.jue scheine result-S into siynificantly reduced delta coke on the catalyst.

(iii)The adsorbent. contacts first with the residue hydrocarbons at the ri ser bottoin before contacting the catalyst particles. The adsorbent in the above mentioned process of coittartIing most of the metals, CCR end o *ther poisons present irs the residue and thereby helps to keep the catalyst. relatively mtuch cleAner froim.

the .above poisons. This greatly impr-oves the overall performance of the catalyst and also 18 brings downi catalyst make tip rate.

(i)The CCR and metal Laden adsorbent can be wi thdlrawn as separate stream from the separator and the adsorbent. burner. Such adsorbent may contain metals as high as 50000 ppm wlich couild be used far extracting the high value vanadium, and ni ckel from the adsor bent and i+4 etnmi cs permit, recycle the rejuvenated adsorbLent. back to the adsorbent bacit to the adsorbent bUrT'le.

(v)In addition, if tile residue feed corsi~i7mns very 208 hi gi, ICR (above 5 s.47.) any 3tate of the art FCC process,. wi I1I requijre enormou01S Cat &lySt COOL i 111.

toi avoid the higcher regenerator tempci attitre. Ins contrast, at- invention takes cis-e of very hi gh CCR qite effi ci entl y. Ihe adsorbent v: -ptures 259 most. of the fer CCR (abouit 90%) in k'?e riser bot t 1m. In su~ch cases o, high feed UiCR-, the preferred adsor-bent is caicined coke so that at niet coke s1.r-etm can be wi thdrawn. 4rt t tie *sepi* ator 4CIf the adsor bent butrner Slich vii tIhdr wt-i cole streari co"Id b e tvsed as feed for ::cokre 'gassifiiation/power or steam A.74Pr a tioan i nside or out~side tihe refiniery. ihe adscir benit burner in siuch cases is r equired to buvrn only that muitch cake, t)hi civ is st'ff ci ent t:o meiai rai n *35the desired tentperatutre of the reecycle zidso-rbert Sto thp riser-. Itiis uritte feature of our invention al~ows the fle":ibility to process residue with very high CCR (eveni beyond 20 tt c4 feed) without violating the overall heat balan-ce o of the, unit. As well Pnown in the current FCC art, *avoiding the combustion oF the- total coke inside the bettery limit of the unit, niot atnly saves the capi tal. investment on the burnier but also helps to control the NOx and SOx eatission of.

the uni t.

V 19 other benefits and details of the Present invention are di sclosed suibsequent IY.

Adsorbent. particles are intended to adsorb the CCRI the poisonous metals e.g. vanadium, itickel etc.

basic ititrogien avid sitl fur rich compoun-ds j i ig i ni enriched from in the residual hydr-oc.- -bar frartionms.

Typically, adsorbeit particles are having particif si in the range of V microns but prefer abl wit: to ~300-400 miro'as. The particles Jens-:* be ILJ ieert 1500-3000 14c rr 3 i-d prtoferably IE300-2600 1-g/m 3 and msof ~efrl 23@0-2500 kg/m 3 Thue present inpnti also applied to adsorbent of particle size higher than 550 microns and density above 351AO 1-g/m 3 but the larger paricle size and density pose flow problem in the stantdpipe and also in the regenerator.

The adsorbent particles mainly consist of the micir-ospheres composed of alumina, silica alumina, silica inagnesi a, Itaol in Clay Or- a ItiXttiwe there o'4f having acidic properties or cavld he toktally non acidic. These itticrospelieres catild tie prepared itsin-g the cr'riventional art of FCC catalyst preparation' i.e. by preparing the solution of desired chemical ccamposit i art, its spray dirying aild calcinatioti. Typically, these materials have very less acidic craciting activity characterized by Hat.

activity of less than 15 and surface area of less than III/grit However our i nvent.i or i- t not lioni ted to Iasi activi ty adsorbent alone. Far example, one may uise the disposable spent catalyst from FCC/Residue Ff.C or hydraprocessing tinits provided the particle size and densi ty are wi thi rt the speci fied ranige of the adscrbent as mentioned above. More details on the above said 1s materials are available in US Patent 5059302.

For- residues containing CCR above 4-5 we prefer that the adsorbent should be calcined coke produced 4r-om calcination of raw coke generated in the delayed colfing process of petroleum reaidtnes. Coal 15 particles or othf-er- types of cake are also applicable but calcined ciL~e are prefer-red due to their- excel lent *attrition resistance and physical properties higher particlie denlSi ty O.tC. Si rice, the peEI:process produces a net coke streama -or high CCR r esi due feedstocf!, stabl e roke parti cle having proper mechiani cal strength, size, shape and density as gentioned herein above, shouild be used. It may Lie noted th,_t if the attrition resistance of the coke is not good, small coke fines %*ill be generated which can not be separated in 21 t the condition of the dense bed separator device. These fines will thereby reach to the regenerator and increase its temperature beyond l imit. Therefore, we prefer a mechanically stable calcined coke rather thaii raw coke.

The other advantage o+ calcined cokte is that it hies higher density, lower stilphur content and lower volatile matt~ers vi5 a vi a raw cok-e.

typical properties of calcined petrtoletrn colke is given below: 1M As-f-% content 0.17 wtV.

Sulfur 1.94 "L% Volatile riatters(YM z 9.33 wtV.

Iron 149 ppm Vanadiu Lin 3.8B ppm Real density 2.14 gm/cc Bulk density 0. .73 gm/cc: Particle dens-ity t.52 gm/cc Attrition resistance 1.2 (division index) The calcined coke was obtained from one delayed C 01,er unit processing l ofng resi due of atmnospheic coluimn, This calcined coke was grinded mechanically to produce the desired particle sirp range between 200-350 microns. It may be noted that when :::CalcinedC- cCIe is u!Sfd aIS the td-sor bellt, the major intention i5 to drave a separate stream of net col-:e from 22 the separator/bur-ner so that the unit heat balance is properly satisfied. Therefore, fox- safe retise/disposAl of the nek. coke drawon -from the process of ULIAs i nventijon, it is preferred to Use calcined cake- alone, whenever i t is pref erred, wi thouit. addi ng any other adsorberit compoients as nienti ored above.

Fo~r residue feedstock cantairv.-ng higher aftiotirit of vanadi ,.ut (above 10 ppmj) btit havii~ st CR l ess than 2 wt7., we prefer to use commercial ly available vervedium traps such as V--trap additive of M/s. Intercat USA~. rhl~is could be used alone or- in adminture woith other adsor bent Lctmparent as mentioned nbove except calcined coke. The concentration of Vanadium, -reap in the mixture of other adsorbent component may vary from B-100 wt/ depending on the concentration of Vanadium in the feed, but usually 10-40 wt X is considered sufficient -for feed having vanadium upto 50 ppm.

In case, the feed contai ris higher emouit of both vanadium and CCP., we prefer to uise calcined col~e as the ads~orbent, siir,:e cal ci ned cok~e has ci st very good metal trapping ability. It. may be noted tha. rat* cokce could be used in otnr application. Buit the calcined coke 15 0S 20 23 is preferred in ou-r- process. This is due the fact that our invention involves high velocity separation and ri ser- operation with- the adsorbent partic)es which demand good attrition resistance and retatively higher per-ti cie density. Cal ci ned colfe has ver y good attt i t ion resistance which is equiv/alenk. to or- better theii even conveit i olE31 FCC catalyst and its particle density is also mare than raw coke. Inb general it maey be noted that all these particles shOUld meet the reqt.tir-enenlts of parti clIe size and/or particle density or both in order to achi eve the max imum segjregati on ef f ici ency i rt the separ a tor.

typi cal parti Cle adsorbent particles are given 15 20 70 Adsorbent size distribution of the belIow: Particle Size microns 320 350 365 375 385 390 400 24 The adsorbent particles preferably shotild be microspherical in nature. iowever the present i nventi on i not IJimi ted to other shapes of per tic] es.

C~onvent iorial state of the art commercial catalyst used in FCC technology, may be emoployed in this J nvent ion. However, the present invention specific~ally describes the particle size of the catalyst to be within 20-200 mict otis and more preferably 20-170 mirrons and 143 most preferably 20-40th microns. Similarly, Lhe particle densi ty ma~y be wi thin 1200-1800 kjj/m' 3 and mor-e preferably 1300-160QI kq/m e nd mast preferably within 1300-1400 Ig/su 3 to obtain best rVeSLults as disclosed in the present invention. Like adsow-benk.s, catal Yst sh-ould be preferably micro-spherical in sheope. The present invention is not restricted to any partictilar type of FCC catalyst. T-herefore, rare earth exchanged Y zeolite, Ultrastable Y zeolite, non crystalline acidic :mat r ix and even other reolites- e. g. shape s'elect~ive 281 ZSM-5 zeolite may also be used. TUhe present invention prefers to have no CO promoters since the both cataly-st regener-ators and adsorbent btirier of the present :inventiont slwiotld preferably run itt partial 1ni. huIt. i on mode. Hovo,'ever, our invention is riot limited COt promoter usage particular-ly when the feed contains CCR lower than 2 wt Typical partiicle size distribution of the catalyst microspheres are: Wt% Ad-sorbent Particle Size microris 0I 2 W 150 Th7r0n netonpoie oe aproc to hi 0 105mtl n ohrpios axmmbnft i respctiely preen mnentlinludeovdnsa noeld approalh t aydl esda n htdrthatbour hinaveyo phfietghyalo h CCR, metals and other- poisons. aiu ei~ti of the feed to deposit on the adsorbent first before contacting with the caLalysL. Moreover-, a riet. coke :..025 stream is withdrawn from the process wshich helps to maintain heat balance quite easily -for feedstocL.; with 990 high CCR.

999 0 26 CAVLSTj SEPARA'fER The spent catalyst and adsorberfl mixture enters the separator near middle of the elevation. rhe separator acts as a vessel to segregate the ratalyst from the admar-berit. particle. The separator- warks on the principle of da+ret~eo transport velocities among two types of particles i.e. catalyst and adsorbent. In the prior ar't, Usually settling velocity differeice haes been employed for such separation. We have di scovered now that the best segregation efficiency is achieved by utilizing the transport velocity difference whiich is further ilixistrated in Example-A. of ther- pr esent i nverkti on.

A~ccordinlgly, in the preferred embodimtent, the is having an entry line -for- the spent adsorben t:-cat a]yst mnz tttre and operating withini a tenpera-tUr-e range of 450-600 0 C arid preferably %within 490--5500r,, a specified superficiali velcity rarige which is at least. 207. above the transport velocity af the ~largest and heaviestt cetalyst particle but at. least. *307.

Lower than the transport velocity of the, lirjtest. and finest adsorbent particle, where in steam is irojected at the bottom o-f the separator- to maiintain a dense 27 fluidized bed o-f adsorbent. and transporting the spent catalyst particles through a lift line having reduced diameter than that of the separator with additional steam injection points and withdrawing the adsorbent to the burner kept at. lower elevation than the separator.

The most important feature of our separator device is that suich high efficiency separation of ctalyst, is achi eved i.sing steam at low t:emperature.

The zteato iti the separator serves many ptirpose and such 19 low tetMpjrature separationtji ies followi rig import ant benef it s: lift the catal yst parti cles to the tcop of the separator- li-ft line end maintain a deinse bed of adsorbent inside the separator; iii) strip ouit the remaining hydrocarbons from the spent adsorbent -and catalyst mixture in co-current transport regime at fairly low teemperature. This *..reduces the delta coke on catalyst and adsorbei-t. and at the same time minimizes the thermal cracking reactions which occur -in high temperature and conventiooal counter current strippers with relatively larger contart time; (iii) for- high CCR (above 5 vwtX) residtue feed, it is possible to draw a relatively cooler stream of net coike from the separ ator while tising cal ci ned coeas adsorbernt. Stich lowm temiperatuire adsorben~t stream require less cool in-g requirement for its dis'pos-al or, reuse. fhost. intpurt ail y, the I-et corke withdrawn helps to solve the high t~emperature prohleni associF ated wai ti high CUR feed. Sirtce Elhe cake is wri thdrowin from the system, only that rtuch heat is allowied t~o be gerfn'rated from cake burniing vwhich is required to meet the reactor [teat demlelid. The other advaintage' is thmt th'e rost Iy treatment of flue gas rould avoided since the flu~e gas 28 SO_. anid NO-. are cat-siderably reduced in the preset inventtion ildue to low temperature regerterntion and removal of significanrt quantity of coke as separate stream WithOUt burning; (i V) the separatdor can soinetimes act as a dense bed to supply adsorbent to the riser bottomn rar-ti cul ar when the -feed CCR is very low (less then 2 bujt mnetal s i n the feed are relatively higher. In such0 casesi adsorbent: burner is niot necessary arid optirx~al 18 streafn of hot regerterated catalyst froim the regjenerato~r mnay be added tn the separator to maintein its temperature up to 600'3CU ntaximumf, so that hot adsorbent stream can be drawn from the separator bottom for recycling to the riser; The 9team along with the hydrocarbons separated i ni the cyclone from the catal yst are rects~bl e as stripping steam in the conventional catalyst. stripper arnd or as lift steam/atonioration steam in ri-sc'r bottom and 4eed nozzle or for similar application-, in the process lines. of riser/reacator/stripper sectiott.

CATALYST R GENERATOR The lifted catalyst from the separat-or is separated +rau, the steatt and enstting hydrocar-b#onrs in a cyclone or a series of cyclones. The catalyst psarticles 5 fall through the cyclone dipieg to~ the denise bed of the regenerator. In the present embodiment as t::hown in 2, st..perficial. velocity is mainitained 1: piceaily within 0.5-1.0 m/s and more preferably withit 0.6--tO.B rn/s to have a conventional. dense bed regeneration of the 6*0-10catalyst. However, otur- irivenitiofl is also applicable to 0*fast fluidized comibustor or eventosaerenear desi gns.

:29 I he exces's air is 9Maintained Such that preferabl y parti al combuistion i s achi eved and the coke an regenerated catalyst is preferably less than 0.3 wt.

In the partial ciobtxstioni aode, chances of vailadium deactivation a f catalyst particles reduces significantly. Moreover, heat generation per un it of coke burnt also reduces resulting into higher catalyst to oil ratio in the unit. However-, total COMbLSti.r May also be employed along wit~h the present invention where 16 the regenerator temperature is Eept with in the limit of 7509C. Since the feed CCR and metals are preferentially deposited on the adsorbent particles, wte do not ex-pect too much colte lay down ont the catalyst. Theref ore, it may not fie difficuilt to keep the regjenerator temperatuire wi thi n Ii mi t. It may fie specifically Mentioned that our invention does nat require any catalyst cooling even processing of high CCR feedstock. This is due to the selective deposition of CCR in the adsorbent high fi ci ent-y and low severity segregation of catetlyst from 26 adsorbent separate withdrawal of coke stream from the *****adsorbent separator and or burner for mairita-irting heat *balance without requiring catalyst coaling.* ADRBENT BRNER The burner usually runs on the partial :":"0125combustion mode tinder controlled air flow in dense bed fluidzatios- regime. The coke btrnt +ram the adsor-bent s sufficient to maintain the bUrner temperatitre wi thiin 0 9C and most preferably within 68001,. '1he-. eXCess o,:ygen in, the flue gas could be in the r-ange 0-2 volY% and CO/CO 2 mlay vary in the range 0.2-10 vol/vol. Ther e i s no MO.liffmUM limit on the coke on the edsorbhent.

Usually, it is observed that at higher concentratioin of coke on the adsorbent, the vanadium and CCR tr appi ng ability of the adsorbent i mproves. However, 4for 18 practical reasons, the coke content on the ad-r;crbent is kept in the range a* 0.3-2 wt%.

IThere is- provisicii to vaithdrawi a nr-t stream of coke ftain the bi.wner when the residue conteins feed wi th CCR above 5 wt7. arsd th~e prefer-r-ed adsorbheit: in such 0 O5 case is cal citied colte. This helps to process heavy CCR residue wi thoi it violi-A irig Che heant bal ance. T he burner can also rtun in total combustion mode, althouigh it is *0.

0 not desi rable fr om heat bal ance vi ew point. The flue gas of the burner and the regenerator could be ii,ed together before sendi ng to, CO boil er or energy recover y 0 00000sect ion.

*RISER

In this section, the adsorbent particles 00 conting fromf btirner or separator are fir-st cc:.,tnrted with preheat.ed heavy residiial hydrocarbon in presence of lift Steam. lypically, lift and feed atomirtio.n steam 4 abottt 10--56A wt% of feed may be added in the bottom esectioti of the riser dependinig on thle quality o+ residue particuilarly CCR content. The adsorbent/oil ratia and the stearn/or ratio are variled in the +ol lowitic raflgex Feed Typical Adsorbent/Residual. oil Steam/Residual CCR lilI ie wt7.

3 0.

7 5 0.7 The superficial velocity is maintained in the range of 6-10 rn/s typically which will be sufficient to lift the adsorbent particles through the riser.

:The regenerated catal yst is iniPcted at t',e intermediate elevation of thle r-iser. ihe cLalyst/ital hydrocarbott is Ifept normallIy i rt the raw-,e of 4-6 wt wt to achieve best posvible r-estl ts. Mhere is provi -ion for injecting separate ed stream at- thle jritermedi r e riser elevatio- above the entry point of the regener;-Ated :catalyst. Such feed stoul d have CCR, ai-etal anid other Z 32 poiS(~ sri.L- less as possitne but. definitely I ov'eer then those of the esi dual stream injected at the r-iser bot t cM. Tryoric example of such cleaner streams are fresh vacuium, gas oil, heavy cycle oil recycle etc, The r iser top temperature and the intermediate temperature just. belovm the catalyst entry point could be used to Control c at alyst /oilI arid adsorbent /resi dtue ratios respectively through the corresponding sdlide valve.

Total residence timfe in the riser bottom sectiort could to be 10-40%. of the total riser residence time. The catalyst resideice time in the riser may be maintained between 1--15 seconds and pre'erably between 3-0 seconds depending on the severity of the operation desired.

Stripping steam may be injected at the hottom, the stripper- and/or at different elevak-ions to achieve better stripping efficiency. Usual) y, 2-5 tons per- 10e00 tons o-f solid flow is the normal Yrate o4 total steati flow in the stripper. One imkportald here 219 is to maintain higher velociLy of the Fitrippiog gas typically above 0.2 rn/s so thit the coarse -:ar licles are at least above the minimium fluidization velocity.

Specially, irt th-e standpipes and at the b(ittomr of thte stripper, steam puiroee is given to keep the adsnrber-A. and the catalyst mixture -flaweable. 9tiher non conventional s-tripping e.g. fns Ittdit'ized Stripping, hot. Stripping etc. may alsii be adopted but -nat essentie-J in the pr esent i vn erit i on. Th i 5 'S heCaUse, thr c~taI yst separator also ef.Oa*nceq St-ripping efficieic. C.0 current st i ppi ing ti iii hi gh vEeri ut 1 Ly if+t. steiiritas described earlijer.

~EXMLE 1 Ihis exampiii- illustrates the relaionship of is Super f i c i A hec ve Ioci ty "wit h t he segrega tioan eff+i c iency of 8 duatl Sol id system. A gl ass col umn wi th fol Iowi ng design speci-Fication is used for the Stt~dy.

Col umn di atteter 5 i nch Column height fr-am airentry paint :35.4 inch Wal 1 thi rkhtess 0. 196 ifnch Disengage height above column 12U? inch Disenyjager D~iamneter 8 inch *Sand is used in the ize range of .220--320 micrcns twith par-ticle density of 2600 kg/rn 3 Cat-alyst 29 is in the size r-arge of 40-J50 microns voith particle diensity of 14~50 ifcj/is Fypi cal ly 800 gills of 50/50 by wt aof sand and catalyst mix ture is loaded and ai r i s i :t irect ed at the buttom of the column at di f fer-ert 334 Velocities. Solid sample is co~llected near bolttomr of the column Just. abalve the air entry point. Ifie par icle sir~e di str ibuti on of the call ected so-i d i s done~ to establi sh aefHount of segregation Ahak. has taken place.

For 100% segreqatiot, the collected sponple' Shold d contain no -varticle of size below 20P micrc i.e. the cut off size betweeii sand and :atal yst. Vo I lowing results are obt.ajnec- "hent 11- air velocity is I cr eased for a flixlJLrF-e weith !tart~ rg inventory of E30 gr ans Of IS vst. mi:d ture.

.Supel Ii r-i Ed oct segregation efficiertcy (meters/sec)

V

0.65 47 01.72 58 0.79 69 0 86 76 0. ?2 00 Q1.02 E14 I1t i s f otnd that i ricre'asi rig Super 4 i ci a) veloci y Si gnif icanti y improves the* segregati on e-ff ici ency. SuIperf i ia 81VelOC'il:y With J1ASt abUVP I meter/ser 9egregation of abouit 84% could be achieved.

The other imaportant observation is that beyonid certain velocity, the segregation efficiency actually tapers off. This could be possibly due to the entraintment, of lighter and relatively smaller fraction of the adsorbent with the Lransported catalyst particles. iher-efore, iL may be noted tt-at the stiperfirial velocity ill the separator is to maintained such that it is sufficient to lift and tranispartI even* thec heaviest and l argest range of catalyst. particles but distinctly insifficient. to be able to lift the fin-est and lightevA. porft orl o+ the adsorbent. Ill other- words, the separatoir bed velocity should be above the transport velocity o~f the catalyst but lower thari that. of the adsorbent. For the size and den-sity of the sandc and catalyst as me-ti oned above in this extample, the trarnsport and settling velocities are: Settling Velocity Transport veloity Catalyst. .1.3 Sand 1.13 Typically, for FCC catalyst perticles having particle density u-f 1450 k/3the tr-ansport velocity var iat ion wi th the average parti cl e si ze i s givYen betlovo :average pa-ticte size transport velocity Smi r r oi0 ec) *I eel 150 36 200 2.3 2548 2.8 303 As seenu above, the variation in' transport velocity with average particle size is quite significant and even more prominent than the differ-ence in their respect ive settIi fg velocities. Therefoare, the transprt velocity difference is exploited in this invention to maximize the seyregatiot efficiency betwen Lw3 types of particles.

This ex arplIe illustrates that if thle superficial velocity is maintained around 0.6-0.7 in/s as done in conventional dense bed regime, it i Snolt possibl~e to achi eve more+ U-san 591-607. segr eatiouan eff+i ciency. This ex~ample also highlights that the proper linawledge of the transport velocity of bath adsorbent and catalyst particle is very esse'ntial to mnax i i Ze the solid segregation efficiency of the separ ator.

EXAMPLE 2 This eXamnple MiStrateS the benefits of sequential dual solid processing particularly the vanadiUm deposition preferentially on the adsorbent particles and thereby improving the activity of the FCC catal yst.

1 37 v For this considered.

pur-pose follolding Saelples wt were

S

S

Catalyst A ReIJSY (rare earth exchanged ultra stable Y) based FGC catalyst ,amplIe (commerci al I y availIable from 1/S. AKZO Nobel, the Netherlands ine trade name Vision 56M1) Adsorbent V-trap commercial additive from M/S. Inter-cat, UsIi. But wi th particle size in the range of 250-350 micron.

Vanadi um i s first deposited (by adopting pore voltsise impregnation route of Mitchell) at M~ and 10068 ppmn on the mixture of catalyst A and adsor bervt B mixed in the rat-io o-F 190.6.

Typically, the MM'T activity was determined usi ng MAT (micro activity test) conditicir of 510oC reactor temperature, 2.5 grains solid loading, M seconds feed injection time and varying feed ratv to generate date at different conversion level. Feed itsed is the combined feed used in one commercial FCC uttit. with CCR 0.4 wt%, boiling range .370-5i6Q'C, density o-C 0.91 gm/cc.

Thereafter, the Vanadium i S deposited selectively on the adsorbent D at E,166i66 ppm iising same pare vulumffe ji pregniati on techn1ique. The mfetal I aderi 2 .3f%

S

adsorbert isthen mixed with th-e catalyst A in the same ratict of 8-6: 10- MAT activity and proiluct selectivity were ifeaS.Ured' uSi ng t he samte feed with this sol id mi,-tttre as performed in above.

Faw the salke of cvltpari son, MAI studi es were also dcone with ani y Catalyst. A (wi thotit adding any adnor bet-t)', both att 0 and 10000 ppm vanedi urni levelI.

Following results are obtained: Mat activity is defined as Elhe coiversioTn obtained at 1.*SV of 114a hour-j and conver sion is defined ast the prodict. boilinig below- 2160~C iicluding Coke.

Vanladi trn Cat al yst Vanadi turn Van ad i urn level ,ppn3 A deposited an deposited a L1mO1 S. A r e nly Adsorbent 16.5 37.5 U' 16,600' 38.6 10. 1 COKFi IffC1VT Situiln'rly, the coke svlectivity Chat'ges with vanadium are giveni below, with both comnbine~d as tsell as Sequential processi ncj of Solid. tiere, cokre sfe]ectivity 3 9 i s de-fi ned as the cok.-e yield (wt% of feed) at 383 wt conversirin l evel.

Yanadi tizr, Cat 81 yst Van ad i urn Yekild tim level ppin Adeposi Led art deposited only Composite Ceatalyst on Atdsorbent Adsorbent 81.87 10065.93 3.62 1.9 It is observed here that if no adsorbent is used, vanatdium at. 10000 ppm concentration, brings dowen the conversiont very significantly fram 383.6 to to 10.1 unit, which improves to 16.5 wihen the adsorbent is used combi ned wit$h the catal yst. However, vahen sequential vanadi.tm deposition is done- first an the adsorbent before mix~inrg witH tile catalyst, the solid mi tUrL shiows al most the conversion as if no vanadi ui i s there.

Similar case is observed onl the colte selectivity also.

Sequential vanadium deposition on the adsorbent first is able to provide coke selectivity almost same that of the catalyst wi th-out van~adiumn.

From the above, the importance and advantage of first depositing vanadium selectively on the adsor-benit is clearly observed. There has been remarkable retention oF the catalyst activity, coke and other product sel ecti vi ty i f thle YAviadi urn i S prefer-entially deposited an the adsorbent first befare gettirtg inr coritact with U te aCltUal cat&i yet.

:46

C

Claims (9)

1. A~ fluidized catalytic craicking apparatus comprising a riser having a feed inlet far introduction of the feed stream containing heavy residual fractions with high concentrat ions of conradson coke, metals such as vanad-it un, nici-el arid other poi sons such as itrgei said riser having a 4irst inlet -for- introduction of high velocity steam a second inlet +or- iritradtiction of the feed, a third inlet for- introduction of. an adsurwbet and 18a fourthe inlet disposed above said third inlet f or introduction of the regenerated catalyst, said riser extending into a stripper fo~r causing a 5eparationv of hydrocarbon fraction fr-am the spent. catalyst and adsorber, said stripper connected to a separator for causing a separation of the adsorber from the catalyst, said separator havinrg an inlet for injection of steam, a 9burner in flaw cafftmuni cation with said separatir for receiviing the adsorher and causing a regeyipr at ion *':~:thereof a regeneratoir in flaw commuicatiort with said separator for regenerati rig the ttatal yst separated ini the ::sepstratak said buirter having an outlet in flow cotomnicaior wi th the third inlet for introduction of the adsorber into said riser, said regenerator having an 41 outtlet, in fliow cornmuni cation with said fottrth inlet for i ntrodtict iort of said regenerated catalyst irito sai d ri set

2. A fhatidized catalytic cr ac k ing apparattus, as in claim 1. wherein the distance between the third and f our th inlets is 20 to 40% of the riser Length.

3. A fluvidized catelytic cracking appetrsius as claimed in claim 1 comprising a down-comner between said 16~ separator and burner for allowing a flow of the adsorber from the separator to the burner.

4. A fluidized catalytic cracking apparatus Lqs claiated irt claim 3 whierein said burner has ani inlet for introduciort of air for cattsing a combustioni withiin said burner and causing a reactivation of the adsorber A fluidized catalytic cracking apparaitts as claimed in claim 35 wherein said burner has a purge :outlet for discharge of coike.

6. A fluidized catalytic cracking apparatus as claimed in claim I wherein a riser is contected between the separator and regenerator for allowing the flow of ~the s_!pent catal yst front the separator- to the r egenerat. 42

7. A flsiidized catalytic crack~ing apperatuts as clIa imoed inr claim 4 wherei n sai d bur ner i s dis.posed below of said meparator.

8. A fluidized catalytic cracking process F or Sconverting heavy /Acuum gas oil and residual oilI fr actions into ligchter products comrpr isinrg inr first contacting a heavy residue feedstock with an adsorbent so that th-e impurities on the adsorbent in the botom of a riser, allowing the feedstock and adsorbent to U3 contact a catalyst so as to cause a cracking reaction, the catalyst. and adsorbent being separated from the product hydrocarbons -in a stripper, the mfixtulre Of* catalyst asid adsor-bent. being introduced into a separator for causitiui a separation of the spent catalyst fromt the adsor-beri it- the presence a4 steam arid at a temper atitre of 450-6000Ci., the spent adsorbent being intr'diured inito a burner arid the activated adsorbent recycled ito said riser, the spent catal yst beinig regener ated inf a regenerator and then introduced into said riser.

9. A process as claimed ini claim 13 wHerein the temperature within said separator- i~s prefe'-ably between 4 90-550 0 C. :43 A process as claimed in claim 8 wherein the temperature within said burner is maintained eat 600- 759, and preferably between

640-680 0 C. 11. A Proacess as claimed in claim 8 wherein the temperature within said regenerator is 600 750 t3C, and preferab] y 6 50-- 6 12. A process a5 claimted in claim 8 wher-eirt the temperature within said riser is 450-650 0 C arid the velocity at )east 10%. above the maximnum trarisport to velocity of the adsarbent. particles. 13. A process as claimed iii claim 9 wherein -said catalyst is shaped selective pentasil zealite and CO promoter wit~h the particle's having particle size in the range of 20--200 micron and preferably 20-100~ iicrons and the particle density from 1200Q-1800 kg/m"3 anti preferably within 1300--1400 kg/m. *14. A process as claimed in claim 10 kierein the adsorbent is acidic or non acidic alumina, silica- alumine, Itaclitsite, commercial vanadium traps particles and the ini-.t.ure of the said components having particle sire of 200-500 ati crats and preferably 300QACM microns with the particle density in the range of ii-_-,00 kg/ift 3 arid prefer-ably in the range of 1800-2600~ kg/rn 1 44 A process as claisned in claim 9 wherein said adsorbent: is calcined coke for heavy feed containitig CCR of about 4-5 wt%. and -above. 16. A process as claintedin claim 8 whereiii the adsorbent. to residual feed r-atio in thbe riser bottom is in the range of 10:1 to 1:2 wt/wt. 17. A process as claimed in 8 wherein the toa steam flow to the hydrocarbon flow in the riser bo~ttom section is in~ the range of .0~5:1 to 1:2 wt/wt.. Lim 1.8. A process as cl aimed in claim 6 "herein the catalyst to total hydrocarbon in the riser is maintained in the rainig of 3zA to 15:1. DAE hs8t dyo INIA OI.OPRTO IIE By thiPtntAtony CULE CO