US2587669A - Processing liquid hydrocarbons - Google Patents

Description

March 4, 1952 w. w. WEINRlcH PROCESSING LIQUID HYDROCARBONS Filed Jan. 5, 1950 Lira/WZL? GHS INVENTQR UIiHiam lll. 111m E SEER MISSOK WQNK Patented Mar. 4, 1952 UNITED STATES PATENT OFFICE y 2,587,669 PROCESSING LIQUID HYDROCARBONSV William W. Weinrich, Wallingford, Pa., assignor to Houdry Process Corporation, Wilmington, Del., a corporation of Delaware Application January 3, 1950,` Serial No. 136,444

(Cl. 19E- 52) 14 Claims. l

; The present invention relates to systems and methods for conversion or other processingy of hydrocarbons in contact with a granular contact mass and is particularly directed to improvements in the operation of suchV systems. wherein the granular mass is circulatedto andfrom a reaction zone or treating zone. The invention is especially concerned withthose systems and operations wherein the granular contact mass during such lcirculation iselevated fromv a lower to an upper level in the system by a liftinguid stream.

Various hydrocarbon conversion. or treating operations employ systems of the type above designated; for example in. catalytic conversion of hydrocarbons using a, moving bed of. adsorptive granular, catalystV asin cracking', desulfurization, reforming. etc. Other operations coming into consideration include those whereina granular contactmasahaving little or no catalytic activity, is. employed chiey as ameans of transferring contained sensible heat to an oil to be processed, Whether for the purpose ofthermally cracking or precoking the. oil, or for heating the same to requiredreaction temperature or to vaporization temperature in the caseof previously unvaporized liquid oils. While certain aspects of the present invention are applicable to operations. of the various types hereinbefore designated, the inventionwill be more particularly described in connection with the cracking of normally liquid hydrocarbons in contact with adsorptive catalysts to productsof.. vlower boiling vpoint and lower molecular weight, such as products in thegasoline boiling range.

Normally liquid hydrocarbonswhen subjected to certain elevatedtemperatures, Whether or not in the presence of acatalytically activemas's; break down to form solidcarbonaceous or'hydro-i carbonaceous deposits called coke As a general rule higher boiling hydrocarbons ata' givencracking severity display'a comparatively Agreatertendency to form coke deposits. Where'such coke material is inherently orconcomitantly formed as a result of contact of hydrocarbons at elevated temperature with catalyst or otherj adsorptive contact mass, the cokeable material is deposited in' the. contact Pmass, and can be' periodically apparatus. as a resultl of coke-producing hydrocarbonsremaining on the hot walls thereof, in many instances constitutes a .severe problem, oftento the extent of precluding practical adapttion of a-processing technique that' would other-A wise be highly desirable from the standpoint of enici'ency and economy of operation.

In catalyst circulatingsystems wherein the elen vationofthe catalyst iseffectedby a vapor stream form, to take advantage of the heat content of removed therefrom by transporting the' thus contaminated mass, in the course'fofits circulation, to a regeneration'zone' wherein the mass'is contacted at ignition temperature'witlroxygen-con;-

taining gas to eiect combustion of the coke and resulting'restcraton of the mass forfrther'use in thehydrocarbon'processing'operation. Accu p mulationof coke'orrconta'ct mas'siwhich cannot besubie'c'ted to regeneration, or Vontp'ari';s"of"the l the catalyst for vaporization of liquid, and"par` ticularly in handling of hydrocarbonswhichare not readily volatilized below coking temperatures. These drawbacks arising from coke accumulation when charging. non-vaporized hydrocarbons to avaporlift, are elciently overcome by vthe novel arrangement and operating `method of the present invention.

` Inaccordance with the present invention,.cata lyst. or other hot .granular contact material is continuously. supplied 'to a .transfer zone orhopper to form a bed of the material at the foot of and surrounding a vertical lift conduit. A' gas or vapor lift medium is passeddnto the bed ofV contact material under pressure so as to cause elevation of the contact material into the-left-conduit, and transportation through that conduit. Hydrocarbons to be" converted or otherwise proc"- essed are admitted in liquid state directly within the lift' channel to engage the upwardly moving contact material therein. Within the lower p'ortion of the lift conduit and in' the region to which the liquid hydrocarbons are admitted, the'contact material is present in comparatively high concentration and is moving in its impelled path constantly upwardly in the lift channel; there.. fore the liquidhydrocarbons are subjected to con# -ditions which favorcomplete and uniform distribution of liquid onthe contact mass. yBy oper-- ating in this manner the coke that may be formed. asa result of'subjecting the liquidhydrocarbons to the high temperatures prevailing in the'viciity ofthe lift hopper, is depbsitedi or on 'thecoitact? material that is ini positive upward. motion and which' n' be subjected to' reg'eeltio'n'- BS required, thereby avoiding the possibility of forming interfering quantities of coke deposit within the lift hopper, as on the exposed walls thereof or on any stagnant or relatively slow moving' contact material that may be present therein.

In typical procedures directed to the preparation of a charge stock for catalytic cracking, a bottoms fraction of crude oil or other high boiling fraction containing heavy ends which are not vaporized at the prevailing heating temperature, may be sent from the preheating furnace to a flash distillation zone, providing a vapor effluent and a high boiling liquid fraction. The system and operation of the present invention are advantageously adapted to the handling of both the liquid and vapor products from such flash distillation zone. Conveniently such vapor products may be employed as all or part of the lifting uid for the granular contact mass, while theliquid hydrocarbons are introduced directly into the lift channel on the moving contact mass as above indicated. The vapor introduced into the transfer hopper for lifting or assisting in lifting of the granular solid contact material therein is, of course, not limited to such vaporous effluent from flash distillation, and may be any gas or vapor not incompatible with hydrocarbons, but is preferably hydrocarbon vapor and/or steam. When hydrocarbon vapors are employed as lifting fluid or to assist in lifting the granular catalyst or other contact mass, such vapors may comprise all or a part of the vaporous eiiiuent from a tar separator or other flash distillation apparatus. The liquid hydrocarbons may comprise the non-vaporized fraction from flash distillation, preferably free from tars as such and from undesirable salts present in tar residues. .Alternatively the liquid feed may be composed in whole or part of heavy liquid separated from products of cracking, either recycled from the particular cracking operation or from some other source.

The operation of the novel features of the invention will be better understood and other advantages thereof appreciated from the description K which follows, read in connection with the accompanying drawings illustrating several alternative embodiments adapted for practice of the invention.

` Figure 1 is a schematic diagram of a systemA for circulating catalyst or other contact mass, particularly illustrating the arrangement of the lift conduit and vessels directly communicating therewith.

Figures 2, 3 and 4 are enlarged partial views p'.

in vertical section of different modifications of details of the transfer hopper and the lower portion of the lift conduit. Figure 5 is an enlarged view` of an additonal detail.

, vReferring now particularly to Figure 1, there i;-

is shown a transfer hopper I, into which catalyst or other solid granular contact material is continuously admitted through a run down conduit 2, to form a bed within the hopper maintained at a substantially constant level as indi- ,in a separating or disengaging vessel 5, which vessel is provided with a discharge conduit 6 at or near the bottom thereof.

4 the lift conduit 4, above the bottom of that conduit. The conduit 4 is surrounded by a concentric sleeve or housing 8, which terminates at its lower end approximately at or near the level of the bottom periphery of the lift conduit 4. There is thereby formed between the outer wall of conduit 4 and the inner wall of sleeve 8 an annular chamber 9, which is open at its bottom end I0 and sealed at its top end I I. The top end of the sleeve is in communication with a vapor supply line I2. At an upper portion of the hopper I there may also be provided a vapor inlet line as indicated at I3 (see Fig. 3) for purposes which will hereinafter appear. It will be understood that the sleeve 8 may be formed in other than cylindrical shapes and need not completely sur- 'round the lift conduit.

, Details of the hopper I and its associated parts are better shown in the enlarged views of Figures A liquid feed line 1 passes upwardly through the bottom of the hopper I and terminatespwithin 2, 3 and 4. Referring now particularly to Figure l2, as illustrated, the bottom of hopper Ia is shaped to conform in contour substantially with the path of iiow of the contact mass in the hopper when passing down the hopper and reversing direction to pass upwardly into the lift conduit 4. With a hopper bottom of approximately this shape the quantity of non-moving or relatively slowly moving contact mass in the hopper is reduced to a practical minimum.`

The liquid feed line 1 may be simply a pipe having an open end terminating within the conduit 4 and discharging a stream comprising liquid hydrocarbons into that conduit. If desired, the stream thus introduced through line 1 may contain some vapor materials such as steam or vaporized hydrocarbons. In some instances it may be preferred to discharge the liquid hydrocarbons into ythe conduit 4 in atomized condition. One suitable arrangement for effecting atomization, accordingly, is illustrated in Figure 2 and shown in greater detail in Figure 5. Thus the feed line 1 may be provided with a T-coupling I1 or other pipe fitting having a lateral opening communicating with a liquid supply line I8 and a connecting branch for reception of a vapor supply line as shown for instance at I9. The vapor supply line I9 may be equipped with a discharge nozzle 20 of reduced cross section. Admission of an atomizing gas or vapor through line I9 approximate the intersection of line I8 will cause atomization of the liquid introduced through line I8 and consequent discharge as an atomized stream through feed line 1.

In the operation of the embodiment illustrated in Figures 1 and 2 the lift vapors, such as steam and/ or hydrocarbon vapors are introduced at the required pressure and in required quantity through line I2 into the annular zone 9 between the sleeve and the lift conduit. These vapors flow downwardly in the annular zone and issue through the bottom I0 of the zone as an annular stream, which flows to a level somewhat below the lower end of conduit 4. These vapors then reverse their direction of flow and pass upwardly into the lift conduit 4. In doing so the vapors contact granularL material from the bed in hopper I (or Ia) adjacent the lowerends of sleeve 8 and conduit 4, and lying in the vapor path, causing the granular material to pass beneath the lower periphery of conduit 4 and upwardly into that conduit. The granular material is then impelled upwardly in the conduit 4 by the vapors passing through that conduit, and is discharged from the upper end of the conduit into the disengaging vessel 5. Because of the expanded cfiiss7` section@ of theysseli 5;' the? vapors? dise" ed therein from conduit 4 lose velocity?to"l raniiiar material is-vfno longer f' an I the granular material' iiieafbyeente'rsienteY seme extentte' cracked;

pese enligne which may' 'be steenr er1 other inert;-

gas; admitted" into the? catalyst inletfleg 2v may be 'introduced al? a' suitable" pressure so` that'r a portion of the` gas ilows'concurrently with"the' catalyst and down" that leg, entering the" space above vth'e catalyst level in the hopper. Alternatively csi-"in addition-such seal gets-might be 111-' troduei' directlyintoth hopper above the cata# lyst level by meansvof the valve-controlled inlet liii "|'3`.` The` use of steam for this purposeV has tla'dvantagvof providing at least a" po'rtioniolfv thef stanr that maybedesired to' be employedv as lprocss"stearii added to' the: hydrocarbonvconvex-i; Si'v reactiony The vapors `el`i`i`g`th lift' conduit 4' together Witl' V'fp's f'r illthalt -C'Ondllit by'vaporz'ai#L tio'afl'coii'yesiohf (ifl the liquid feed 'introduced 'tlll' w line-'1 aredischarged together" with the cataly'sti'ntothe disengagerv vessel 5. Unvapor.L Y liquid', if there bev any, Will be adsorbedon' the catalyst; and Will be Vvaporized or converted byflni'i-rlinginContact with thecatalyst iii the' accumulated-bed thereofv formed in the'` Vessel-Y 5; during gravitation ef that bea toward the die: charge outlet-of that' vessel; A'I'he' vapor products dirscliarg'*edatftlieV topY of'theY lift, pass dovvn wafmy 'through the catalyst' benj inith'e vvessel-1 5 .are lSubjelctedj to further 'conversion theifebyf the" vaporous4 conyersion' products" beiig dischi A fromthecatalystin"passingover a'suitabl' solid-gas cisenga'ging means 211, whithnittype injtheforrn of 'a tubefv sheet lralfi'nrg'fshortdepeifiiI iiigtiibes thereiuer thefw'eii kiiettii tueur-tha 'f elsdS-enig'ager.' The vapors thus disengaged-are disohalfgd from the Vbottom of the? vessel 5 nby' Ineans'of a dischaigeiline 22 from Which tlfieyfnov'lJ to apparatus for 'separation into desired fractions and further'proces'sing as desired.. Below the'disfengaging means 21 the catalyst' enters'thedi'schargeconduitt through which it'mayffloyv` to vt silitabliejl kilnfor regeneration by combustion' of thefjcokein the catalyst. Before admission tothe kiln',` litHWilly be understood; the catalyst will be subjected to .a purging" operation tolremoveiesserbes iiquius' end tapers: The *eateiystinj di"- eliluent discharged through line' Inivanyicase the catalyst is ultimately" regenerated`and?reL anular materiel wiir be' eti-a;

' maintained.

turned .inft regenerated forniv frein the kiln' through the' catalyst inlet conduit 2-for repetition'Ezv of' the''described cycle.

In an alternative processing arrangement ernploying the apparatus illustrated in Figures 1 and2` the vaporsadmitted to the annular cham` ber'9f may.v consist of steam or lighthydrocarbon:

gases, and if desired crackable hydrocarbons may be admitted as the atomizing gas into the fitting Il through line IS.

admitted through line rI9;VA such steam assists in vaporization of the liquid hydrocarbons.

In `the modification shown in Figure 3 the lift gas,which mayY consist of or contain vaporize'd" hydrocarbons, is supplied principally through a jet'23 atthe bottom of the hopper l terminatingl in an outlet spaced vertically from the bottom of conduit 4 and providing therebetween a gap 24 into which the granular mass continuously flows, and is picked up by the ejected vapors discharged through jet23 and lifted thereby into th'e conduitl Again, as inthe previously described:

ein' 'dimentg theA liquid hydrocarbons are" adrrii'tt'ed into the'lift conduit through the -liq'uid s'iipply linel l, which may be brought in concentiicallyrthroughthelarger pipe 23, as illustrated.

or' may'beothervvise'lbrou'ght intoVv the hopper l'w poking' tendency'as compared With the'less r ct''y heavy'ends of the oil, maybe intro'- duced through line I3, steam" rbeing 'introduced thi'ou'ghje't v23'. l

Instead of bringing the liquid feed in concentrically into thebottom ofthe lift conduit 4, in anjalternative arrangement as illustrated'in igure 4 5 the liquid hydrocarbons may be introduced tliroughone or more laterally intersecting pipes 2f-ata1ievel `abov'ethe bottom of the lift conduit; Such pipes 26 maybe simply provided with an open end'at the discharge-outlet thereof into the conduit 4,'. 0r may be, equippedl With screened hea'dsio'r diffuser nozzles;

Asi'further` illustratedfin Figure 4, the" total reizl'uirem'ent of lifting' Vapor in arrangements employing the sleeve' 8V surrounding the lift con duitfll; need no'tlbesupplied through line l2, but an-auiiliary vapor inlet may bei` provided, as shown at 27,1 to paesi' tapers yu'p'wetuiiy "through the catalyst' bed. Thus theY vapors admitted through? line 2T mingle withA the vapors discharged'fror'n the annular! 'chamber 9 passing together-upwardly into the conduit'- 4 Vand eiect-l elevation ofthe vgnanular contact material ehgagedby thesevapors.I By regulating the rate and quantity of vapors'l respectively v admitted tllrr'oughAlinesulgV and 2l ef'cient-'controlof the circulation ra'tof the Contact vrmateriall can; b n y t I The vapori` introduced through lines-{Zand- 27 lmay befof the same vor different composition for 'instance' steam: maybe adriiitted thrt'rughv Jowneof these lines vandhydrocarbons vapors*throughftlfeiothen The line 21 may be amp'penfV 'ended i pipe: or may 'be4 provided with Y a K In operations wherein hydro'"y carbons are admitted through-line I2 it may be preferred to` employ steam as the atomizing gasl 7 diffuser head of suitable design. As shown at 28, the discharge outlet of the pipe may be provided with a suitable baiile or screen to prevent granular ,material from falling into the pipe.

Common to all of the described embodiments, the introduction of the more readily cokeable liquid hydrocarbons into initial contact with the catalyst or other granular material takes place in the lift conduit proper or closely adjacent thereto in the channel traversed by granular material that is already positively directed in its upward path for entry into the lift conduit, there by avoiding the possibility of undesired coke accumulation within the hopper l (or la), and rendering unnecessary the elaborate precautions. that might otherwise be required to safeguard against the building up in a comparatively short period of an accumulation of coke in the hopper to an extent interfering with the lifting operation. By restricting, the liquid introduction to the lift channel and particularly to within the lower portion of the lift conduit, the liquid thus admitted contacts the -catalyst in (l) comparatively dense phase, yet (2) at a point or zone at which all of the catalyst is movingpositively upward in a path of xed lateral boundary delineated or prescribed by the diameter of the surrounding wall of the lift conduit. These two conditions prevailing at the point or zone of liquid introduction are further explained below.

In a lift pipe of uniform cross section at a given mass circulation rate, the catalyst concentration at any level withinthe pipe will vary inversely with the catalyst velocity at that level. Just below the entrance to the lift pipe the catalyst is changed in its direction of movement and an upward force imparted thereto so thatthe catalyst is accelerated in upward direction from zero velocity in that direction to a positive velocity during a comparatively short distance of travel within the lift conduit. The acceleration thentapers off, but the velocity is progressively increasing to reach a, maximum at or adjacent the top outlet of the conduit, so that the concentration of the catalyst at a given uniform mass fiow rate is thus vconstantly decreasing. Accordingly the highest catalyst concentration within the lift conduitA prevails near the bottom of the conduit. The point of liquid introduction between the ends of the lift conduit is preferably one at which the catalyst concentration is at least equal to 10% of the apparent bulk density of the catalyst in a random packed bed thereof. By so choosing the point 0f liquid introduction, ordinarily, there will still remain a path of travel of the catalyst or other contact mass within the lift conduit of sufficient length to assure good distribution of the liquid on the upwardly moving granular mass, which liquid may be adsorbed therein or adhere thereto as -a surface film, and without having free liquid as such discharged from the conduit, or remaining on the walls of. the conduit to deposit coke thereon. The same considerations apply in arrangements employing a lift conduit that is tapered or otherwise constructed of increasing diameter in a direction toward the top thereof. In such instances, however, although adequate catalyst concentration may be had at levels higher up in the lift conduit than in the case of a lift of uniform cross-section, the introduction ofthe liquid is preferably at a point sufficiently low that the liquid has adequate time and distance to become well distributed in the catalyst prior to its discharge from the conduit, so that no liquid oil as such is carried over in thevdisengaging vessel 5.

It is also given as a, condition that theliquid introduction is at a point or zone at which all of the catalyst is moving positively upward. I mmediately below the bottom of the lift conduit and over Ia short projected cross section of that conduit constituting a part of the lift channel, positive movement of all the catalyst is established. The lift channel therefore comprises not only the catalyst path within the lift conduit surrounded by the conduit wall, but includes a zone of substantially the same lateral dimension for a short distance below the foot of the lift conduit. This distance may vary to some extent with the vapor velocity and with the relative position of the bottom of the sleeve 8 with respect to the bottom of the lift conduit for this type of vapor lift inlet; or mayvvary with the length of the gap 24 the types of inletsystems illustrated in Figure 3. In either case the -zone in which positive upward movement of catalyst is assured includes that distance below the bottom of -the lift conduit proper, no greater than approximately one-fourththediameter of the lift conduit, which zone is there fore embracedwithin the designation liftchannel. By thus distributing the introduced liquid on the contact mass that hasentered or is entering the'lift conduit, coke formed from lsuch liquid will be carried on the contact mass `and will be ultimately burned in regeneration of the mass. l

The total quantity of liquid hydrocarbons introdueed intothelift certainly should not exceed the amount that can be adsorbed by the catalyst or` will adhere to the contact mass supplied'to the zone of solid-liquid contact. In practical operation, even in the case of adsorbent catalyst, the point of saturation of the hot catalyst with liquid hydrocarbons, will not be the determining-factor in fixing the maximum ratio of liquid oil to cata-- lyst, since conditions of desired heat transfer to achieve thermal balance in such practical operations may Vlimit the total amount of liquid that can be charged, to a figure well below such point of saturation of the catalyst. For instance atypical pelleted catalyst having a porosity say of 50 volume percent can theoretically adsorbv an amount of liquid oil substantially equal to one half thel apparent pellet volume of the catalyst, given sucient time,` and not taking into account continuous vaporization of theoil with or without accompanying cracking. In practical operation, however, the amount of liquid oil charged should not exceed about. 1/3 of the catalyst volume, and in fact taking into consideration the relative temperature differential between the oil and the catalyst that is most convenient in such operation, and considering also the heat required and the reaction temperatures desired to be maintained inthe principal conversion reactor, the amount of liquid oil charged vwill be preferably below 1/4 of the catalyst volume. The quantity of vaporized hydrocarbons charged in addition to the liquid hydrocarbons, will depend upon the operating conditions established for the principal reaction zone (compact movingA bedvreactor) including the selected catalyst to total hydrocarbon ratio as one of `these conditions. Such additional vaporized hydrocarbons may be introduced, entirely or onlyin part into the lift conduit, as previously described, to serve as lifting vapors,` and additional hydrocarbons may be brought into the compact bed reactor, if needed to make up the required hydrocarbon to catalyst ratio.

9 Asa general rule, practice of the invention does .not necessitate a departure from the usual processing conditions used in conventional systems lion carrying out hydrocarbon conversion reac- "tions, for instance' those employing gravitating 4compact beds of catalyst or other contact mass, as in catalytic cracking vvof hydrocarbons to gasoline',y catalytic reforming ofV naphthas to products tof improved quality, or correspondingnon-catav lytic''operations wherein the 'granular' contact `'massis relied upon chiefly for heat transfer.

" ",As lcatalysts for hydrocarbon cracking operations there may be employed'the known siliceous and other cracking catalysts including acid-activated clay pellets or synthetic silica-alumina in the form of cylindrical or spherical pellets (beads), of a size range designated as granular as distinguished from nely vdivided powders 'of up to`100-200 mesh size. Such granular catalyst or other solid contact mass is characterized bythe fprope'rty of forming compact beds throughwhich gase'sand vapors can be passed upwardly atpractical operating velocity without significantly disturbing the bed, as distinguishedfromnely di- "vide'd 'powders which are impelled or form.fluid vizedv bedsby l.passage of gases or .vapors` therethrough at considerably lowervelocity. The granular catalyst or other contact mass employedin Hpractice of the present .invention .should generjally .be of a size greater than about .05.-inch in .major dimension, and up ,toabout 0.5,inch.

' Ininstallations wherein the chamber5 isemv.ployed to accumulatethe contact mass as a bed `'of ,suilicient height to serve as a gravitating bed reactor, V.this chambershould .be `maintained,at ,.suflicientpressure ,above atmospheric 'that the vapor. products discharged through line22 can be .sent to further processing without necessitating pressure boosting. Generally the pressureat the `discharge line 22should be in the order of at least about pounds per square in chgaugalso that .witha pressure-drop of about 4one pound or more through the bed in vessel 5, the pressure above the v,bed .wouldbe atleast 7. poundspersquare inchv or more. `llllicient andsmooth operation of the lift ,andadequate solids concentration` for adsorption of thefliquid hydrocarbonfeed is. generally had under conditions'providing a pressure drop of vabout 1 .to about 12 pounds per square inchin `the A lift conduit 4, so that the. pressure in hopper I immediately below the conduit 4`Will be the sum Ao f .th e pressures prevailing at the discharge end ...the lift conduit Zand Vthe pressure 'drop "in that fc duit. The required pressure in hopper I thereb determines the .pressure rof introduction of vapors throughline l2 or line 23.'

VThe disengaging vessel 5 need not be operated to ,accumulatea rbed of granular Contact material 1`,of"""sig`nicant` height."y For example, the tube r"sheetor other partitionfzl mayhie'omittedland the discharge conduit 6 may be ofjsuch diameter as to'be `capable of. transport ing' the granular i'bon conversion reactor'as the granular mate- "yersion reactor, the4 pressure in the disengaging vessel should advantageously be higher thanV that `prevailing at the reactor inlet.`

ExamplmevI The following example illustrates a typicaloperation in the practical yadaptation of the invention ,as applied to processing about 2000 barrels ofpilwpe'r `day as fresh feed. The arrangement is based on the use ofv a unit compri/sing" a'f12 --inch .diameter lift conduit ofabo'ut`2'00 -feet inv height.

EastQTexas crude oilis fractionated and the bottoms fraction constituting about"l0% of ylthe totalerude separated. This fractiomhavinga Agravity 01223.7" A. P. I. and an initial boiling point Itigres@ F., 80% boiling up to 1o14 F.; is admitted at appropriate'temperafure to a ilash yapori'zation zone, such as a conventional tar separator. operating at a temperature of 850 F. at a pressure of about.17.5 p. s. i. gauge, steam being admitted to the zone at the rate of Yabout- 24:37 poundsper barrel of oil charged. .Allofthe yaporizedhydrocanbonsand steam withdrawn overhead are sent tothe lift hopper .to operate as l'fapor lift medium, entering the hopper at about the ash distillation temperature. The non-va- `'porizedhydrocarbons, constituting about 31.5% of the. oilcharged vto the lash vdistillation zone, are'removed as a bottomsifractionand sent toa .vacuum flash ,distillation AZone toremove the heavytars and saltA contaminants. Theyauum distillation zone is. operatedatv a pressure Qf abeut 100. mm. of mercuryand steam isgaddedsthere to at .the .rateofapproxirnately 2.9 pounds Aper -barrel of oil. `About one-,fthof the original 40% bottoms fraction. ofthe v crude oil, is dischargedas .taibottoms from the yacuum ,distillati9n zone. while-.the o verhe'ad therefromis permittedto condense and .pumped as liquid feed 2 3.4 A. `vPLI.

gravity)..to. the lift throughhline 1. @On the basis .oanl original 2,000 barrelsper day charged to. the flash .distillationzona .this will provide vfor vintro- '-.duc tion.in to thelift about 12,50 barrels of hydro- .carbon yapors at lthe stated. temperature plusmthe .addedsteanr andiabout 3 50 barre ls Qfliquid feed at .about-,650 F. yFreshly. regenerated synthetic silica-aluminay bead catalyst at about 1 0 00f 11'. en

ters thelift at arate giving aweight ratio.. of catalyst tooil of 6 to l. The pressureattheiootgof the. lift is maintained. at about 15. p. s..i. `gauge 1 and at thedischarge outlet ofthe lift,.in the dis- Cracked Products heavier than vg Lbs/Hr.

c; fre@ Gasoline (375 r. 90%).

C4 Cut Dry gas Coke burnoir 3. Barrels per stream. day.

In-the foregoingwexample a virgin oilffraction was charged as liquidy feed toA the lift. .Inan al- VLternative operationlthe vapor overhead* from .the

rflash distillation zone is used -asflift mediums perdre,- biituuie 1iduid.feed coiistitdts recycled are obtained the following products:

-Jdom packed volume of the granular contact mass.

eration is described in the following example.

amZeI Ex p I The catalytic gas oil is pumped as liquid and introduced into the lift through line 1 at '700 F., the lift vapors from ash distillation entering at about 850 F. Freshly regenerated synthetic silica alumina bead catalyst is admitted to the hopper at 1000 F. or somewhat above. Under approximately the same cracking conditions aS employed in the previous example, but employing 625 bbls./day of liquid feed at about 700 F., there BPSD Lbs./Hr.

C4 free gasoline (375i F. 90%

Catalytic gas oil (boiling above gasoline) C4 cut Dry gas Coke burnoi F., while in some cases the liquid feed may be attemperatures as high as 900 F., or above. In certain operations-the entire liquid bottoms from flash distillation may be sent directly to the lift Without removal of the heavy tars. Various other sources of liquid feed may be used, such as slop oil from a lube refining operation.

Since the vaporization of the liquid hydrocarbons takes place essentially within the lift conduit, the vapors thus produced do not signicantly influence the catalyst circulation rate. Accordingly, uncontrolled changes in catalyst flow rate that might result from variation in the nature or condition of the liquid'feed, if it "were vaporized in the lift hopper, are avoided.

The term apparent bulk density as herein employed, has reference to the weight of a ran- In the case of silica-alumina bead catalyst of about 0.12 inch diameter that has been in use 'andlmaintained at equilibrium activity, the apparent bulk density is about 46 pounds per cubic foot.

Obviously many modifications and variations of the invention as hereinbefore set forth may be madefwithout departing from the spirit and scope thereof and therefore only such limitations should be' imposed as are indicated in the appended claims.

I claim as my invention:

1. The method which comprises continuously supplying hot granular contact material to a transfer zone to form a compact bed of said material in said zone, passing a gaseous stream compatible With hydrocarbons into said bed under pressureto cause elevation of a portion of the contact material and suspension in said gaseousA A stream, directing the gaseous stream and contact material suspended therein into a vertical elongated channel commencing below the `top level of said bed, flowing the gaseous stream past the contact material in said channel to impel the contact material vertically upward in said channel, admitting into said channel liquid hydrocarbons to directly engage the upwardly moving contact material therein, said liquid hydrocarbons being admitted to a lower portion ot said channel and in a region wherein said contact material is present in relatively high concentration as compared with higher regionsof said channel, whereby said liquid hydrocarbons are completely and uniformly distributed on said contact material, the contact material in said bed and directed into said channel being at a temperature sufiiciently high to cause coking of said liquid hydrocarbons; whereby the coke produced as a result of conversion of said liquid hydrocarbons at the temperature prevailing within said transfer zone and in said channel is deposited substantially entirely on the moving contact material.

2. The method of treating liquid hydrocarbons which comprises engaging hot granular contact mass with a vapor stream to effect elevation of said mass into and through an elongated vertical channel under the impelling influence of said vapor stream, said vapor stream being compatible with hydrocarbons, distributing liquid hydrocarbon oil on the vertically moving contact mass at a level within said channel at which said contact mass is present in suspension in the vapor stream in an average concentration of not less than 10% of the apparent bulk density of said mass, said contact mass being at a higher temperature than said liquid oil, transferring heat from the cont-act mass to the oil to effect vaporization of the oil within said channel, discharging the contact mass and oil vapors thus formed into an expanded disengaging area, maintaining engagement between said oil vapors and said contact `mass thereafter to effect at least partial conversion of said vapors to lower boiling hydrocarbons, discharging the contact mass into a heating zone and heating the same in said zone to restore the temperature of said mass, and returning the thus heated contact mass to further eng-agement with saidA elevating vapor stream.

. 3. The method in accordance with claim 2 wherein the quantity of liquid oil distributed on said contact mass is not in excess of that quantity which will be converted to vapors prior to discharge of said contact mass into said disengaging zone. y

`4. The method in accordance with claim 2 wherein said liquid oil comprises hydrocarbons boiling above the range of gasoline.

5. The method in accordancev with claim 4 wherein a portion of said' hydrocarbons boiling above the range of gasoline are converted to gasoline during contact with said contact mass, thereby concomitantly depositing coke on said contact mass, and said heating of the contact mass in the heating zone is effected by combustion of the coke thereon.

6. The method in accordance with claim 2 wherein the quantity of liquid oil distributed on said contact mass is not in excess of one-third by weight ofthe contact mass.

7. The method in accordance with claim 2 wherein said vapor stream engaging said contact mass comprises hydrocarbon vapors from distillation of a liquid hydrocarbon oil fraction and said liquid oil distributed on said mass comprises at least a part of the unvaporized residue of such distillation.

8. The method of hydrocarbon conversion which comprises engaging a hot granular adsorptive contact mass with a vapor stream compatible with hydrocarbons, to eifect elevation of said contact mass into and through an elongated vertical channel, admitting hydrocarbons in liquid state into said channel to contact said granular mass for heat exchange therewith thereby effecting at least partial vaporization of said hydrocarbons within said channel, and separating the contact mass from said vapors beyond said channel, said liquid hydrocarbons being introduced into said channel at a locus wherein the contact mass is in positive upward motion and is present in suflciently high concentration to adsorb the liquid hydrocarbons contacted therewith, and the sensible heat content of said contact mass is sufcient to effect vaporization of said liquid hydrocarbons and to eifect at least partial cracking of said liquid hydrocarbons to lower boiling products.

9. The method of hydrocarbon conversion which comprises vertically moving hot freshly regenerated granular cracking catalyst through an elongated transportation zone under the impelling influence of a hydrocarbon-containing vapor stream, the concentration of catalyst within said transportation zone decreasing in the direction of movement of said catalyst, admitting hydrocarbons in liquid state within said transportation zone directly into contact with said vertically moving catalyst and at a locus in said zone wherein the catalyst concentration is at-least equal to of the apparent bulk density of the catalyst to effect distribution of the liquid oil in the catalyst, said liquid hydrocarbons being at a temperature below that of the catalyst, maintaining contact between said liquid hydrocarbons and said catalyst in said transportation zone for a time suiicient to eiect complete vaporization of said liquid hydrocarbons by heat exchange with catalyst within said transportation zone, and contacting the hydrocarbon vapors thus formed with the catalyst beyond said transportation zone to further crack said vapors into lower boiling products with accompanying deposition of coke in said catalyst, regenerating the coked catalyst and returning the regenerated catalyst for engagement with the transporting hydrocarbon-containing vapnr `stream.

10. The method of hydrocarbon conversion which comprises continuously supplying hot freshly regenerated granular catalyst at hydrocarbon conversion temperature to a transfer zone to form a compact bed of catalyst in said zone, passing a vapor stream compatible with hydrocarbons into said bed under pressure to effect elevation of catalyst from `said bed. directing said stream and the catalyst elevated thereby into a conned vertical elongated transporting zone and owing said stream past the catalyst within said zone to impel said catalyst vertically upward through said elongated zone to a disengaging zone wherein said stream and catalyst are separated, introducing hydrocarbons in liquid state into a lower portion of said transporting zone and into engagement with upwardly moving catalyst therein, maintaining contact between hydrocarbons and catalyst in said transporting zone for a period sumcient to vaporize liquid hydrocarbons and partially convert vapor and liquid hydrocarbons to lower boiling products, and again contacting a mixture of said vaporized hydrocarbons and lower boiling products thus formed with the catalyst after discharge into said disengaging zone to effect further conversion of at least a part of said mixture into lower boiling hydrocarbons; the catalyst being contaminated with coke formed by conversion of hydrocarbons in contact therewith, being then separated from hydrocarbons and regenerated by combustion of the coke therein to provide hot freshly regenerated catalyst at hydrocarbon conversion temperature for supply to said transfer zone.

11. The method in accordance with claim 10 wherein said liquid hydrocarbons are introduced at a rate not in excess of the liquid hydrocarbon adsorption capacity of the catalyst at the temperature and catalyst concentration prevailing in the region within said transporting zone wherein said liquid hydrocarbons are introduced.

12. The method in accordance with claim 10 wherein the rate of introduction of liquid hydrocarbons into said transporting zone is related to the rate that the catalyst is supplied to said zone and to the heat content of said catalyst, such that the total heat content of the catalyst is suiHcient to supply theheat required for vaporization of the liquid hydrocarbons and for the endothermic heat of reaction for the said conversion of the hydrocarbons.

13. The method in accordance with claim 10 wherein said catalyst and said liquid hydrocarbons are supplied to said transporting zone at rates such that the weight ratio of catalyst to liquid hydrocarbons is at least 3/ 1.

14. The method which comprises subjecting a heavy hydrocarbon oil fraction to ash distillation in the presence of steam to obtain a vapor eiiiuent comprising relatively light hydrocarbons and an unvaporized liquid residue comprising relatively heavier hydrocarbons, introducing said vapor eilluent containing steam and said light hydrocarbons in vapor state into a bed of hot freshly regenerated catalyst under pressure to impel catalyst from said bed upwardly into and through a confined transporting zone, admitting at least a portion of said relatively heavier hydrocarbons in liquid state into said transporting zone to engage upwardly moving catalyst in said zone, said relatively heavier hydrocarbons being admitted at a lower portion of said transporting zone and in a region therein-where the catalyst concentration is relatively dense, so that any liquid hydrocarbons unvaporized by contact with the catalyst are adsorbed therein during movement o1' the catalyst in said confined transporting zone, and whereby coke formed by conversion of hydrocarbons in said transporting zone is substantially entirely deposited on catalyst in said transporting zone.

WILLIAM W. WEINRICH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,412,152 Hun? Dec. 3. 1946 2,437,222 Crowley et al. Mar. 2, 1948 2,440,475 Jacomini Apr. 27, 1948 2,487,961 Angell Nov. 15, 1949

Claims (1)

1. 2. THE METHOD OF TREATING LIQUID HYDROCARBONS WHICH COMPRISES ENGAGING HOT GRANULAR CONTACT MASS WITH A VAPOR STREAM TO EFFECT ELEVATION OF SAID MASS INTO AND THROUGH AN ELONGATED VERTICAL CHANNEL UNDER THE IMPELLING INFLUENCE OF SAID VAPOR STREAM, SAID VAPOR STREAM BEING COMPATIBLE WITH HYDROCARBONS, DISTRIBUTING LIQUID HYDROCARBON OIL ON THE VERTICALLY MOVING CONTACT MASS AT A LEVEL WITHIN SAID CHANNEL AT WHICH SAID CONTACT MASS IS PRESENT IN SUSPENSION IN THE VAPOR STREAM IN AN AVERAGE CONCENTRATION OF NOT LESS THAN 10% OF THE APPARENT BULK DENSITY OF SAID MASS, SAID CONTACT MASS BEING AT A HIGHER TEMPERATURE THAN SAID LIQUID OIL, TRANSFERRING HEAT FROM THE CONTACT MASS TO THE OIL TO EFFECT VAPORIZATION OF THE OIL WITHIN SAID CHANNEL, DISCHARGING THE CONTACT MASS AND OIL VAPORS THUS FORMED INTO AN EXPANDED DISENGAGING AREA, MAINTAINING ENGAGEMENT BETWEEN SAID OIL VAPORS AND SAID CONTACT MASS THEREAFTER TO EFFECT AT LEAST PARTIAL CONVERSION OF SAID VAPORS TO LOWER BOILING HYDROCARBONS, DISCHARGING THE CONTACT MASS INTO A HEATING ZONE AND HEATING THE SAME IN SAID ZONE TO RESTORE THE TEMPERATURE OF SAID MASS, AND RETURNING THE THUS HEATED CONTACT MASS TO FURTHER ENGAGEMENT WITH SAID ELEVATING VAPOR STREAM.

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