US2556198A - Process fob converting hydro - Google Patents

Description

June 12, 1951 R. c. LASSIAT raocsss FOR CONVERTING HYDROCARBON MATERIAL 2 SheetS -FSheet 1 Filed Dec. 19, 1947 INVENTOR. Raymund Clam/1a? B Y Armmmx I June 12, 1951 R. c. LASSIAT PROCESS FOR CONVERTING HYDROCARBON MATERIAL 2 Sheets-Sheet 2 Filed Dec. 19, 1947 INVENTOR. Raymond Giana/1m Patented June 1 2, 1951 UNITED STATES PATENT FIE PROCESS FOR CONVERTING HYDRO- CARBON MATERIAL Application December 19, 1947, Serial No. 792,724

My invention relates to a process of converting hydrocarbon material.

For reasons known in the art and as referred to generally in pending application Serial No. 766,714, filed August 6, 1947, now Patent No. 2,5};8312, it is desirable, in the art of converting hydrocarbons, for liquid phase hydrocarbon material to be applied directly to hot contact material as it gravitates through a reaction housing'. This is true particularly when the charging stock contains heavy fractions because the latter, in the presence/of the gravitating contact material, are either vaporized and converted, or converted directly to lower boiling products.

In the process and apparatus herein disclosed, contact material," in bed formation, gravitates through a ho g and, in known manner, forms the conversi n orreaction zone proper. Above this bed, in accordance with my invention, contact material having suitable conversion temperature gravitates in layer formation along a downwardly inclined path offering the sole resistance to downward movement of the contact material during passage thereof throughout the length of said path and, as this operation proceeds, atomized hydrocarbon material is directed into en gagement with said gravitating layer of contact material. Preferably, the aforesaid downwardly inclined path is defined by the interior surface of an inverted conical member around which the layer of contact material extends in a circumferentially-complete manner and, below which, the contact material falls freely into engagement with "the upper bed surface.

' In a more restricted sense, the inverted conical member is disposed in vertically alined relation "beneath an upright conical member, these members being suitably spaced from the interior housing' surface and arranged in chamber-forming relation so that a suitable atomizer may be supl ported within the chamber. During operation,

5 Claims. (Cl. 19652) 2 features of the character hereinafter described and claimed.

For an understanding of my invention and for an illustration of one form of apparatus with which the invention may be practiced, reference is to be had to the accompanying drawings, in which:

Fig. l is a vertical sectional view, partly in elevation, showing a conversion housing and associated mechanism as constructed in accordance with one form of my invention;

Fig. 2 is a horizontal sectional view, partly in inverted plan, taken on the line 2-2 of Fig. 1 looking in the direction of the arrows;

Fig. 3 is an enlarged vertical sectional view, partly in elevation, showing an atomizer; and

Fig. 4 is a horizontal sectional view, partly in plan, taken on the line 44 of Fig. 3 looking in the direction of the arrows.

Referring particularly to Fig. 1, I have shown a vertical housing I which, in horizontal cross section, may be circular or of any other suitable configuration. The housing I defines a reaction zone wherein hydrocarbon material is cracked or otherwise converted in the presence of contact material C which moves downwardly therethrough under the influence of gravity, the contact material C, usually after regeneration thereof in a suitable regenerating zone, not shown, being introduced into said housing I in suitable manner, as by an inlet pipe 2 extending through the top housing wall at the center thereof.

In the form of the invention herein shown, although not necessarily, a shallow receptaclelike member 3 is suitably supported in the upper portion of the housing i, said member 3 having a central discharge pipe 4 opening therethrough and extending downwardly therefrom. Slidably associated with the discharge pipe 4 is a horizontal valve member 5 having an operating handle extending through and terminating exteriorly of the housing I. The valve member 5 comprises a passage 5a the diameter of which is suitably less than said internal diameter of the pipe l. Below the member 3, a horizontal frame 6 may be suitably'secured to the interior surfaces of the housing I, said frame 6 having an upright (non-inverted) conical member 1 welded or otherwise suitably secured thereto.

In accordance with the invention, a suitable downwardly inclined, path-defining member such as a frusto-conical member 8 is disposed below the conical member 1, said member 8 being supported in any suitable manner, as by a horizontal frame 9 which may be secured thereto and to interior surfaces of the housing I by welded joints or equivalent. The member 8 comprises a lower discharge passage 8a and the upper end thereof may comprise a tubular portion 8b which extends upwardly around the lower portion of the conical member 'I. The tubular portion 82) has interior diameter somewhat greater than the exterior diameter of the lower surface of the conical member I and, by reason of the fact that said conical member I and the tubular portion 81) are symmetrically related to each other, there is an annular slot or passage Ill therebetween having uniform width throughout the circular length thereof. As shown, the respective longitudinal axes of the pipe 4, the conical member I, and the conical member 8 together with its discharge passage 8a and tubular portion 81) are in coincidence and these axes coincide, preferably, with the longitudinal axis of the housing I.

In operation, regenerated or other heated contact material C having suitable conversion temperature passes continuously from the pipe 2 and, to suitable extent, fills the receptacle 3 which defines an upper zone of the housing I. When the valve member 5 is positioned as illustrated, namely, with its passage to alined with the pipe 4, a desired control is effected on the amount of contact material which gravitates downwardly through the discharge pipe 4 from the receptacle 3. The valve member 5, then, restricts the downward flow of contact material under the infiuence of gravity through that part of said pipe 4 above the plane of said valve member 5. After leaving the valve member 5, the contact material engages and is deflected outwardly by the conical member 'I, the contact material thereafter passing through the annular passage III and then engaging and being deflected inwardly by the conical member 8 as a layer L of contact material whereupon, as a generally tubular freely falling stream S, it passes through the discharge passage 8a of said last named member 8. The width of the annular passage III is such that the surfaces defining said passage offer no restriction to movement of contact material downwardly therethrough. Therefore, as the contact material After leaving the aforesaid discharge passage 8a, the contact material falls freely under the influence of gravity generally in tubular fashion until it comes to rest upon and at least partly defines the upper surface of a bed B of gravitating contact material which constitutes the reaction zone proper, the bottom surface of this bed of contact material engaging a tube sheet If horizontally disposed in the housing I and suitably secured to the interior surface thereof.

If desired, a plurality of pipes I2 may be spaced uniformly around the interior surface of the housing I. The upper ends of these pipes I2 communicate with the chamber defined by the member 3, which may support said pipes, and the lower ends thereof terminate at the upper surface of the aforesaid bed of contact material.

They are adapted to be traversed by a portion, preferably a minor portion, as 20% more or less, of the total amount of contact material gravitating downwardly through the housing I. The pipes I2, when utilized, contribute as regards maintenance of the surface of the bed B at a level approximately that of the lower ends of said pipes.

The aforesaid tube sheet I I supports a plurality of suitably spaced depending pipes I3 which open therethrough. The contact material passes through thes pipes l3 and thereafter, in known manner, may be discharged from the housing I for passage through a conduit I4 which should contain a valve 5 utilizable for controlling the flow of contact material therethrough so that the contact material forming the bed B is restricted or impeded as it moves downwardly through the housing I in solid bed fashion under the infiuence of gravity.

Adjacent the lower end of the housing I, any suitable arrangement may be provided for disengaging cracked or converted vapors from the contact material C. To this end, as diagrammatically indicated, the aforesaid tube sheet I I'may sup port a plurality of tubes l6 which upstand therefrom and open therethrough, the tubes IG-supporting a plurality of suitably arranged channel members II, or equivalent, which are disposed in inverted relation so that, in known manner, they may be utilized for disengagment of vapors from the contact material, the vapors thereafter entering the tubes It by way of passages IBa formed, respectfully, therein. Apipe I8 opens through the wall of the housing I below the tube sheet I I and communicates with the space above the adjacent conical piles of contact material. This pipe 53 may have associated therewith a control valve I3 and it is adapted to receive and conduct the converted vapors to any suitable destination.

In accordance with the invention, the contact material, as it gravitates along the interior surface of the conical member 8, is engaged by atoms -ized liquid hydrocarbon material to be cracked or otherwise converted. To this end, .an atomizer A is suitably located within the chamber defined by the members I and 8 preferably inalinement with the longitudinal axis of the housing I and it may be supported in any suitable manner, for example, by a pipe 20 extending from the exterior of the housing I to the interior thereof. The atomizer A should be one which produces fog,

mist, spray or other liquid particles having suit-. able dimensions from the liquid hydrocarbon material admitted thereto and it may be of any suitable character. Preferably, although not necessarily, it is of the general'character disclosed in the pending application of James E. Evans, Serial No. 756,032, filed June 20, 1947.

In the form of the invention hereinafter specifically described, hydrocarbon material which is substantially or totally in the liquid phase is ad mitted to the atomizer A and, hence, it should be adapted for efiicient atomization of material of this character as referred to in the aforesaid pending application Serial No. 756,032 and as illustrated on the drawings of this application; Thus, as shown, said atomizer A comprises a casing 2| having a top wall 22 through which the lower end of the aforesaid pipe 29 opens and to which said pipe is secured. The casing 2| has a lower wall 23 above which said casing 2I comprises vertical and horizontal circular plate portions ZIa and 2Ib related to each'otherin Hydrocarbon material ad mitted by the pipe 20 to the casing 2| passes to and through each of said ports 2 I c. In view of the foregoing, it clearly a'ppearsthat the conical members I and 8 together with the atomizer A are located in a chamber D of the housing I, said chamber D being bounded, at its lower end, by the zone defined by the upper surface of the bed B and, at its upper end, by the aforesaid zone defined by the receptacle 3.

When hydrocarbon material is to be cracked in the housing I, the contact material C hereinbefore'referred to should be catalytic in character and the temperature thereof, upon admission to the housing I, should range between 800 F. and

1000 F; or higher for example, about 900 F. Any

suitable kind of catalytic contact material may thus be utilized such, for example, as activated clay pellets, or synthetic silica alumina pellets or beads, etc. having suitable major dimensions such as between and of an inch;

Other suitable catalysts for cracking include synthetic plural oxide composites, silicious or non-" silicious in character and containing for example; zirconia, alumina or berylli'a. In lieu of a cracking operation, other types of conversionoperations such, for example, as one wherein hydro'carbon material of the character referred to below is desu lphurized under known conditions with catalytic contact material of the general character referred to above, or equivalent. Or, reforming or dehydrogenation of naphtha-s or other normally liquid hydrocarbons may be effected in the presence of the above or other desired types of catalyst; certain of which are well known in the art. In lieu of the conversion operations described above, heavy hydrocarbon material may ,be vaporized and viscosity-broken in the presence of inert contact material of known character.

During operation with suitable cracking contact material, vapors such, for example, as vapori'zed gas oil, naphtha or lighter hydrocarbons having suitable elevated temperatures, as in a range from 850,F. to 950 F., are admitted con- ,"tinuously to the housing I by way of a conduit 24 which should open thereinto at a higher level than the aforesaid pipe 20. Simultaneously, liquid hydrocarbon material such, for example, as a suitable residual stock, topped or reduced crude having temperature elevated into a suitable range as, for example, from 400 F. to 800 F. ischarged continuously through the pipe 29 under superatmospheric pressure ranging, for ample, from lbs. to 200 lbs. per square inch /gauge or as otherwise may be required for causing the atomized liquid material from the atomizer A to engage and properly penetrate the layer L of contact material gravitating along theinterior surface of the conical member 8. The liquid hydrocarbon material thus traversing the pipe passes through the atomizer casing 2| and the alined atomizer ports 210 of the respective sets thereof are traversed, respectively, by streams of liquid hydrocarbon material. The streams of liquid material from each pair of said portsZic engage each other in head-on relation with resultant production of atomized liquid material which, as a mist or fog, moves down wardly i'n inclined relation and, as a circumferentially complete stream, Fig. 2, engages-the con tact material last named. I

The base diameter of the conical member I and the corresponding major dimension of the conical member 8 may be such as is suitable and desirable. Preferably, however," ,these dimensions are substantial, for example, approxi mately one-half the internal diameter of the housing I and, if so, it follows that; the afore said gravitating layer L of contact material is relatively thin. I By reason of this condition and further by reason of the fact thatdowiiwfid movement of the contact material is restricted onlyin the manner described above,' itjf ollows that the atomized liquid material is effectively distributed in a uniform manner on the individual pieces of contact material, This, of course, is highly desirable because promoting the eiliciency of the cracking operation.

The contact material, after movement thereof through the discharge passage 8a, falls freely under the influence of gravity generally asthe described tubular stream S. Further, during downward movement of the contact material along the interior surface of the conical member 8, the thickness of the layer L increasesin a progressive manner until, at the discharge passage 8a, said layer L has maximum thicke ness. Accordingly, it follows that thethickness of the tubular stream S of contact materialis substantially the same as that of the aforesaid-layer L at the lower end thereof. The foregoing is in I accordance with a detailed feature of the in ventio-n. Thus, during operation of "the-atom i'zer A as described above, some offthe. atomized liquid material, instead of being applied directly to the contact material forming the layer L, migrates downwardly and is intercepted by the contact material forming thetu-bular stream S. In addition, atomized liquid m'ater-ial which tends to migrate upwardly through the annular passage I0 is intercepted by the contact material passing through this passage.

Accordingly, in view of the foregoing, it follows that, within the chamber definedby the conical member 8, atomized liquidmaterial is applied in an eirective manner to "'the;,-grav'i-'- "tating contact material. Further, with the disclosed system, migration of atomized liquid material into engagement with the interior surface of the housing I and the pipes i2 islargelyor substantially prevented. Should this happen to any substantial extent, there is resultzintforma tion of adherent deposits of carbonaceous ma terial which, in the course of time, separate into chunks that move into and through the bed B with resultant partial or complete plugging of the outlets at the bottom of the housing I. This, of course, is undersirable and is substantially prevented, in accordance with my invention, as described above.

As stated, hydrocarbon vapors, which in connection with a cracking operation preferably have temperature substantially higher than that of the liquid hydrocarbon material admitted to atomizer A, are admitted to the housing I by way of the pipe 24. These vapors pass through the housing I, concurrently as regards the contact material C, and in the presence thereof are co'n-' verted to cracked products. In so doing, the heat content of these vapors, by reason of the temperature relation referred to immediately above,

assists as regards vaporization of the liquid hydrocarbon material entering said housing' l" through the atomizerA and provide 'a desired control on the relative quantities of contact material and hydrocarbon material traversing thehousing I. Simultaneously, in the manner described above, atomized liquid hydrocarbon material is engaged with the layer L of contact material with resultant vaporization of such atomized. liquid material and formation of cracked products while 7 passing through the housing I concurrently as regards the contact material C. As regards the total charge entering the housing I, the ratio of vapors to liquid material may be such as is suitable and desirable. !I hus, for example, between and 30% of the charge may be in the liquid phase for passage to the atomizer A and the, remainder in the vapor phase for-passage through the pipes 2d.

Accordingly, in view of the foregoing, it will be understood that hydrocarbon material admitted to the housing I by Way of the pipes 2i} and 24 isconverted in the presence of the contact material C to produce cracked products. As the operation proceeds, hydrocarbon vapors, principally, fill the aforesaid chamber D under pressure deter-mined by the pressure existing inthe hereinb'efore described pipe 18. In known mane er, a suitable sealing medium such as a stream of flue gases, is admitted to the top of thehousing by wayof a pipe l a, Fig. 1, this sealing medium being maintained under pressure slightly greater than that of said hydrocarbon vapors last named in order to prevent passage of these hydrocarbon vapors upwardly through the pipe 2. Due to this pressure relation which exists in the chamber D, the hydrocarbon material admitted thereto as described above, is caused to pass downwardly concurrently as regards the gravitating contact material, this hydrocarbon material being cracked in the presence of said contact material and the resulting cracked vapors being disengaged therefrom at the channel members l1. Thereafter, in the form oi the invention herein shown, these cracked vapors enter the tubes 16 by way of the respective passages iEa, pass downwardly through said tubes and enter the space below the tube sheet ll, said cracked vapors passing to any suitable destination by way of the hereinbefore described pipe l8. In known manner and by suitable means, not shown, a suitable gaseous .medium, such as steam is admitted to the lower portion of the housing 5, below the pipe i8 and under. pressure above that existing at the level thereof, to prevent passage of hydrocarbon vapors through the-pipe (4.

As the operation proceeds, the spent contact material C passes through pipes l3 and then leaves the housing by way of the pipe l4. fhereafter, in suitable manner, said spent contact material is regenerated and then returned to the inlet pipe 2 for readmission to the housmg l.

In the form of the invention hereinbefore specifically described, the hydrocarbon material adr -itted to the atomizer A was stated to be substantially or totally in the liquid phase. However, the invention is not to be thus limited. If desired, mixed phase hydrocarbon material (which may be fOli'led from liquid phase and vapor phase material of the same character and proportioned as described above) may be admitted to the atomizer A and, if so, the atomizer should be adapted for eflicient atomization of such mixed phase material as described in the aforesaid pending application Serial No. 756,032. When mixed phase material is thus suppliedto the atomizer A, the quantity of vapors traversing the pipe 24 mayv be substantially decreased or entirelyeliminated, a

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without 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

1. In a hydrocarbon conversion processwherein liquid hydrocarbons contactmoving particles of hot contact material in a conver si on "zone under heat exchange conditions such that said liquid hydrocarbons are at least. partially vaporized, the steps which comprise feeding a stream of said contact material to the upper portion of a smooth, downwardly converging frustoconical impenetrable surface, gravitating said contact material over said surface as a circumferentially complete thin layer of particles, uniformly distributing atomized liquid hydrocarbons on the particles in said layer from an upwardly enclosed location, and flowing said particles downwardly below said frusto-conical surface as a freely falling stream. Y

2. In a hydrocarbon conversion process wherein liquid hydrocarbons contact moving particles of hot contact material in a conversion zone un-. der heat exchange conditions such that said liquid hydrocarbons are at least partially vaporized, the steps which compriseflowing downwardly a stream of said contact material divergently outward from its vertical axis so as to form a circumferentially complete stream which increases in diameter as it moves 'unob structeclly downward, flowing said contact material downwardly. as a freely falling annular stream to the upper portion of a smooth, downwardly converging frusto-conical impenetrable surface, gravitating said contact material over said surface as a circumferentially complete thin layer of particles, uniformly distributing atomized liquid'hydrocarbons on the particles in said layer o upwardly enclosed location belo'wthe c. erging stream of contact material, and flowing particles downwardly below said frusto-conical surface as a freely falling stream.

3. In a hydrocarbon conversion process wherein liquid hydrocarbons contact moving, particles of hot contact material in a conversion zone under heat exchange conditions such that said liquid hydrocarbons are at least '-par.tially vaporized, the steps which comprise introducing a downwardly moving compact column of said contact material into said conversion zone, discharging contact material from the bottom of said column as a freely falling stream, deflecting said stream outwardly from the vertical axis thereof (so by a downwardly diverging impenetrable surface,

discharging said contact material from said down- 4. In a hydrocarbon conversion process where;

in liquid hydrocarbons contact moving particles of hot contact material in a conversion zone under heat exchange conditions such that said liquid hydrocarbons are at least partially vaporized, the steps which comprise feeding a stream of said contact material to the upper portion of a smooth, downwardly converging frusto-conical impenetrable surface, gravitating said contact material over said surface as a circumferentially complete thin layer of particles, directing atomized liquid hydrocarbons at least partially to said layer of particles, intercepting atomized liquid hydrocarbon material that has not contacted said layer with a freely falling circumferentially complete stream of contact material discharged from the lowermost portion of said frusto-conical surface and accumulating the contact material discharged from said surface on the top of a downwardly moving non-turbulent bed of contact material in-the lower part of said conversion zone.

5. In a hydrocarbon conversion process wherein liquid hydrocarbons contact moving particles of hot contact material under heat exchange conditions such that said liquid hydrocarbons are at least partially vaporized, the steps which comprise gravitating a circumferentially complete RAYMOND C. LASSIAT.

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

UNITED STATES PATENTS Number Name Date 768,692 Provost Aug. 30, 1904 2,438,261 Utterback Mar. 23, 1943 2,439,372 Simpson Apr. 6, 1948 2,458,162 I-Iagerbaumer Jan. 4, 1949

Claims (1)

1. IN A HYDROCARBON CONVERSION PROCESS WHEREIN LIQUID HYDROCARBONS CONTACT MOVING PARTICLES OF HOT CONTACT MATERIAL IN A CONVERSION ZONE UNDER HEAT EXCHANGE CONDITIONS SUCH THAT SAID LIQUID HYDROCARBONS ARE AT LEAST PARTIALLY VAPORIZED, THE STEPS WHICH COMPRISE FEEDING A STREAM OF SAID CONTACT MATERIAL TO THE UPPER PORTION OF A SMOOTH, DOWNWARDLY CONVERGING FRUSTOCONICAL IMPENETRABLE SURFACE, GRAVITATING SAID CONTACT MATERIAL OVER SAID SURFACE AS A CIRCUMFERENTIALLY COMPLETE THIN LAYER OF PARTICLES, UNIFORMLY DISTRIBUTING ATOMIZED LIQUID HYDROCARBONS ON THE PARTICLES IN SAID LAYER FROM AN UPWARDLY ENCLOSED LOCATION, AND FLOWING SAID PARTICLES DOWNWARDLY BELOLW SAID FRUSTO-CONICAL SURFACE AS A FREELY FALLING STREAM.

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