US2458498A

US2458498A - Method and apparatus for conversion of fluid hydrocarbons

Info

Publication number: US2458498A
Application number: US694334A
Authority: US
Inventors: Eric V Bergstrom
Original assignee: Socony Vacuum Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1946-08-31
Filing date: 1946-08-31
Publication date: 1949-01-11
Anticipated expiration: 1966-01-11

Description

Jan. 11, 1949. v BERGSTRQM 2,458,498

METHOD AND APPARATUS FOR CONVERSION OF FLUID HYDROCARBONS Filed Aug. 31, 1946 4 Sheets-Sheet 1 CON VEYORJ CONVE/PJ/ON- VESSEL PRODUCT RECOVER Y v 404w Q-W L AGENT OR ATTORNEY 11, 1949. E. V..BE RGSTROM 2,453,498 METHOD AND APPARATUS FOR CONVERSION OF FLUID HYDROCARBONS Filed Aug. 31, 1946 4 Sheets-Sheet 2 AENT on" ATTORNEY Jan. 11, 1949. E v. BERGSTROM 2,458,498

METHOD AND APPA us FOR CONVERSION OF FLUID DROCARBONS Filed Aug. 31, 1946 4 Sheets-Sheet 3 INVENTOR E'fF/C 1455965777054 AGENT 0R ATTORNEY Jan. 11, 1949. E. v. BERGSTROM 2,458,498

METHOD AND APPARATUS FOR CONVERSION OF FLUID HYDROCARBONS 4 Sheets-Sheet 4 Filed Aug. 31, 1946 Patented Jan. 11, 1949 METHOD AND APPARATUS FOR CONVER- SION QF FLUID HYDBOCARBONS Eric V. Bergstrom, Short Hills, N. J., assignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York Application August 31, 1948, Serial No. 694,334

16 Claims.

This invention has to do with a method and apparatus for conversion of fluid hydrocarbons in the presence of a particle-form solid contact material which may or may not be catalytic in nature.

Exemplary of the processes to which this invention may be applied are the catalytic cracking conversion of high boiling fluid hydrocarbons, the catalytic hydrogenation, dehydrogenation, aromatization, polymerization, alkylation, isomerization, reforming, treating or desulphurizing of selected hydrocarbon fractions. Also exemplary are the thermal cracking, viscosity breaking and coking of hydrocarbon fractions in the presence of heated inert, solid materials.

Typical of such processes is the catalytic cracking conversion of hydrocarbons, it being well known that high boiling fluid hydrocarbons may be converted to lower boiling gaseous. gasoline containing hydrocarbon products by exposure to a suitable adsorbent type catalytic material at temperatures of the order of about 800 F. and higher and at pressures usually above atmospheric. veloped commercially into a continuous cyclic process wherein the solid catalyst is passed cyclically through a conversion zone wherein it is contacted with fluid hydrocarbons to effect the conversion thereof and through a regeneration zone wherein it is contacted with a combustion supporting gas such as air which acts to burn off from the catalyst a carbonaceous contaminant deposited thereon in the conversion zone.

This invention is particularly concerned with such cyclic conversion processes or gas-solid contacting processes wherein the particle-form contact material moves through the conversion zone or contacting zone as a substantially compact column and wherein gaseous reaction products or contacting gas and the used contact material are separately withdrawn from the conversion or contacting zone.

In such cyclic processes wherein the contact material is a catalyst it may partake of the nature of natural or treated clays, bauxite, inert carriers upon which catalytic materials such as metallic oxides have been deposited or certain synthetic associations of silica, alumina or silica and alumina to which small amounts of other materials such as metallic oxides may be added for special purposes. In processes wherein the contact material is not catalytic in nature its purpose is usually that of a heat carrier and may take any of a number of forms, for example, spheres or particles of metals, stones or refractory materials such as mullite, zirkite, or corhart material. In order to permit practical rates of gas flow through the contact material which is maintained as a substantially compact column in the conversion zone, the contact material should be made up of Such a process has recently been de- 2 particles falling within the size range of about 3 to mesh and preferably 4 to 20 mesh by Tyler standard screen analysis.

In such processes wherein the direction of gas flow through the reaction zone is countercurrent to the downward flow of the contact material, the maximum rate of gas flow should be limited to that which will not cause boiling of the contact material" or serious interference with its flow otherwise serious difllculties arise such as channeling of the solid and gas flow and excessive attrition of the solid material. In many processes such as,'for example, the conversion of liquid: hydrocarbons to lower boiling gaseous products it is desirable to pass the reactant fluid downwardly through the conversion zone concurrently with the contact material flow. In such processes a serious difllculty arises in the withdrawal of gaseous reactants from the contact material column within the conversion zone. In one form ,of operation practiced-heretofore a row of inverted, spaced, collecting troughs was positioned in the column of contact material within the lower section of thereactor and gas was withdrawn through suitable pipes extending under the ends of the troughs. Such an arrangement is unsatisfactorydue to serious entrainment of contact material in the gaseous streams withdrawn from the ends of the collecting troughs. This entrainment is no doubt partially due to the limited settling space available for settling out of entrained particles under the collecting troughs. It may be further due to the fact that the static pressure under each collecting trough progressively increases along its length with distance from the gas withdrawal point so as to cause a maximum rate of gas disengagement from the solid surface and of solid entrainment along that portion of the lengths of the collecting troughs nearest the end of gas withdrawal therefrom.

A major object of this invention is the provision in a process wherein a gaseous material is contacted with a substantially compact column of particle-form contact material of an improved method and apparatus for withdrawal of gas from said column without substantial entrainment of contact material particles.

Another object of this invention is the provision of an improved method and apparatus for conversion of a high boiling fluid hydrocarbon to a lower boiling gaseous hydrocarbon product in a confined zone in the presence of a substantially compact column of contact material particles flowing downwardly through said zone in the direction of the reactant flow.

A specific object is the provision in a hydrocarbon conversion process wherein the contact material moves downwardly as a substantially compact column of solid particles concurrently to the fluid reactant flow of a practical method and 3 apparatus for withdrawal of gaseous conversion products from'said column in the conversion zone without substantial entrainment of contact material particles in the effluent gas stream.

These and other objects of this invention will become apparent from the following detailed description of the invention. Before proceeding with the description, certain expressions employed herein in describing and in claiming this invention will be defined. The term "gaseo as used herein, unless specifically otherwise modifled, is intended broadly to cover material existing in the gaseous phase under the particular operating conditions involved regardless of what may be the normal phase of that material under ordinary atmospheric conditions. The expression contact material," unless otherwise specifically modified, is used herein in a broad sense to cover any solid material having suitable heat carrying and stability properties for the particular process application in which it is employed, and the expression is intended to broadly cover catalytic and non-catalytic materials.

The invention may be most readily understood by reference to the drawings attached hereto of which Figure 1 is an elevational view of an arrangement of a cyclic conversion system to which this invention is applied, Figure 2 is an elevational view, partially in section of a conversion vessel constructed according to this invention, Figure 3 is a vertical view, taken along line 3-3 of Figure 2, partially in section of a portion of the apparatus of Figure 2 and taken along a plane perpendicular to the face of Figure 2, Figure 4 is a sectional plan view of a modified apparatus arrangement, Figure 5 is a vertical view, partially in section, of a portion of a conversion vessel in which is provided another modified arrangement of the apparatus of this invention, Figure 6 is a sectional view taken along line 6-6 of Figure 5, Figure 7 is a vertical view in section showing another modified arrangement of the apparatus, Figure 8 is a plan view taken along line 8-8 of Figure '7 and Figure 9 is a vertical view, partially in section, of a preferred form of the apparatus of this invention. All of these drawings are highly diagrammatic in form.

Turning now to Figure 1, there is shown a conversion vessel ill, a regeneration or revlvification vessel ii and conveyors I 2 and I3 for transfer of contact material between the conversion and regeneration vessels. In operation particleform contact material is supplied from hopper 40 through gravity feed leg 4i into the upper section of the conversion vessel l0. Used contact material is withdrawn from the lower end of vessel i0 through drain conduit l4. The rate of contact material flow is controlled by valve IS on conduit l4 so that a substantially compact column of contact material is maintained within the conversion zone. The hydrocarbon charge to vessel l0 may exist in the gaseous phase or liquid phase or both. The charge may be vaporized and/or heated and separated into vapor and liquid fractions in a suitable charge preparation system [6 which may be of conventional design. Heated charge vapors may be admitted to the upper section of the conversion zone through conduit I I and heated liquid charge may be admitted through conduit I8. Gaseous conversion products are withdrawn, separately of the contact material, from the lower sectionof the conversion zone through conduit l9 through which it passes to a conventional product recovery system 20. An inert seal gas, such as steam or flue gas may be admitted through conduit 2| into a seal zone maintained at the upper end of vessel III for the purpose of preventing hydrocarbon escape through the gravity feed leg. The rate of seal gas introduction may be so controlled by means of diaphragm actuated valve 22 and differential pressure control instrument 23 as to maintain a seal gas pressure in the seal zone slightly above the hydrocarbon pressure in the upper section of the conversion zone. An inert purge gas such as steam or flue gas may be introduced, through conduit 24, into the contact material column below the level of gaseous reactant withdrawal for the purpose of purging gaseous reaction products from the outfiowing used contact material. The used contact material is transferred by conveyor l2, which may be a continuous bucket elevator for example, to the upper end of regeneration vessel H. The regeneration vessel shown is of the multistage type, well adapted for the regeneration of spent cracking catalysts. Air or oxygen containing gas is introduced from manifold 25 into several superposed burning stages through inlet conduits 26, 21 and 28. Flue gas may be withdrawn from these stages through conduits 29, 30 and 3i, all connecting into outlet manifold 32. The contact material temperature may be controlled by passing a suitable cooling fluid through cooling tubes located in vessel II between the burning stages. Cooling fluid may be introduced into the cooling tubes (not shown) through communicating inlets 33 and 34 and withdrawn therefrom through communicating outlets 35 and 3B. Regenerated contact material is withdrawn from vessel ll through drain conduit 31 through which it passes to conveyor l3. The hot regenerated contact material is transferred by conveyor I3 to reactor supply hopper 40. While the regenerator described hereinabove is of the multistage typ it will be understood that other types of regenerators adapted for regeneration contact materials may be employed within the scope of this invention. The type of regenerator or revivification vessel to be employed will vary depending upon the particular process involved. Any apparatus adapted to condition the contact material to a state satisfactory for re-use in the particular conversion process involved is contemplated to be within the scope of this invention. It should be further understood that this invention is not considered as limited to any particular positioned arrangement of conversion and regeneration vessels or to the particular apparatus described hereinabove for contact material introduction into the conversion vessel.

The improvement of this invention as applied to the conversion vessel in is shown in Figure 2, wherein in is the conversion vessel having solid inlet 4| at its upper end and outlet l4 at its lower end. A partition 43 is positioned across the upper section of the vessel I0 to provide a seal chamber 44 in the upper end of vessel i0. Contact material passes from seal chamber 44 onto the surface of the contact material column 45 in the conversion chamber therebelow through uniformly distributed tubes 46 which depend from partition 43. The partition 43 and tubes 46 combine to provide a gas distribution space 41 above the contact material column in the conversion chamber. vaporized hydrocarbons may be introduced into the gas space through conduit ll. Liquid hydrocarbons enter through conduit l8 which extends across the vessel and is closed on its end within the vessel. A number of branch pipes amass such as I! and 49 may connect into the conduit l8 within the chamber. Suitable liquid spray nozzles 10 are connected at intervals along conduit l8 and the pipes branching therefrom for.

spraying of liquid oil downwardly onto the sur-"* face of the column 45. Across the lower section of vessel Hi there is provided a horizontal partition 50 from which depend a plurality of tubes 5| communicating with the contact material column above the partition 50 terminating a spaced distance therebelow. Thus there is provided a solid settling space and plenum chamber 52 from which gravity flow'of solid from the column of contact material is excluded and. a number of confined passages for solid material flow from. the column, through the settling space onto the surface of the compact bed of contact material 53 maintained in the lowest portion of vessel i0. Contact material is withdrawn from the bottom of the bed 53 defined by another partition 54 through a number of uniformly distributed tubes 55. The streams fromtubes 55 are proportionately combined into a smaller number of streams flowing through orifices 56 in still another partition 51 within the lower section of vessel I and the streams from orifices 56 are proportionately combined into a single discharge stream flowing from the conversion vessel in conduit M. It will be noted that the number of orifices within partition 51 are only half the number of tubes depending from partition 54 and that the orifices the troughs and the inlet to tubes to provide a substantial vertical depth of contact material column between the gas spaces under The resistance to gas flow oflered by this substantial vertical depth of column acts as a seal to prevent substantial flow of gas downwardly through tubes I tion 'of the conversion chamber as a substantially 56 are horizontally staggered with respect to tubes 54. By the gradual proportionate combination of streams into a single discharge stream as described hereinabove uniform withdrawal ofcontact material from all portions of the cross-sectional area of the conversion vessel is insured. The number of rows of partitions with orifices or depending tubes associated therewith employed depends, of course, on the horizontal cross-sectional area of the vessel involved. A substantial savings in space may be obtained by arranging the tubes 5| in the partition in such a manner that the partition 50 and tubes 5| serve not only to define the plenum chamber or solid settling space 52 but also as the first element of the contact material flow control system. Thus, as shown in Figure 2, the number of tubes 5| are twice the number of tubes in partition 54 and the tubes 55 are horizontally staggered with respect to tubes 5|. If the vessel It is of circular cross-sectional shape, the tubes in each partition may be conveniently arranged as concentric circular rows of tubes. On the other hand. for a vessel of rectangular cross-sectional shape the tubes in each partition may be conveniently arranged in spaced apart parallel rows of tubes extending across the vessel. At a spaced distance above the partition 50 there is provided a row of horizontally spaced, parallel inverted gable-roofed troughs 60 extending across the vessel. Under each trough 6|! there is provided a row of spaced vertical tubes 6| terminating on their open upper ends under the trough B0 and passing tightly through partition 50 to terminate on their open lower ends a spaced distance below partition 50 and within the gas space 52. The positioning of the tubes 6| with respect to the tubes 5| may be better seen in Figure 3 which is a vertical view in section of the portion of the vessel involved taken at right angles to Figure 2. From Figure 3 it will be observed that the tubes 5| alternate with tubes 5| along the length of each trough 60 and that the inlet level of tubes 5| is sufliciently spaced below the troughs 50 compact bed or column of gravity'flowing particles. The rate of solid flow is controlled by throttling by means of valve |5 on the outlet H from vessel I 0.- .Contact material passes from the bottom of the column through tubes 5| onto the surface of bed 53 from which it is withdrawn as described hereinabove. vaporized hydrocarbon reactants enter through conduit II into the distributing space "above the contact material column and then pass downwardly through the column concurrently with the solid flow. If the reactant exists in the liquid phase it is introduced through conduit i8 and sprayed onto the contact material column by means of spray devices 10. The resulting gaseous conversion products disengage from the column under troughs 65 and are collected along withsome entrained solid particles under the troughs 60. The gas and that portion of the entrained contact material which does not settle under the troughs passes through tubes 6| into the settling space and plenum chamber 52 which is of sumcient size to permit settling of entrained solid particles onto the surface of bed 53.- The gaseous conversion products are then withdrawn from space 52 through conduit I9.

In the above apparatus the provision of gas space 52 serves a double purpose. Since the space 52 is a single gas space of large volume the static pressure therein is substantially the same at every portion of its cross-section. The tubes 5|, all of which communicate with this zone of uniform pressure, serve to equalize the static pressure at intervals along the length of each trough 50. Moreover, by provision of tubes for gas,

withdrawal at frequent intervals along the underside of the troughs, any tendency for occurrence of unequal pressures due to gas flow along the length of the underside of the troughs is minimized. Not only is the pressure equalized at various points along the length of each trough but also the pressure under all the troughs is maintained substantially the same. As a result the rate of gas disengagement from the solid column under the several collecting troughs is;;uniform along the entire length of each trough and uniform for all the troughs, therebypreventing excessive solid entrainment in the gas collected under the troughs 60. The space .52 also serves as a settling chamber to permit gravitysettling from the gas passing from tubes 6| of any entrained solid particles. I

The invention may take a number-of forms both as regards the type of gas collecting member employed and as regards the baffling which serves to provide separate passages for gas and solid flow. In vessels of circular cross-sectional shape it is often desirable to employ generally circular collecting troughs arranged concentrically instead of straight parallel troughs. Such an arrangement is shown in Figure 4 wherein concentrically arranged circular rows 90, SI, 92 and 93 of curved troughs may be seen. Each circular row is made up of four curved troughs each covering a quarter of a circle and being closed on its ends. An inverted conical shaped trough or collector 94 is provided in the center of the vessel. The tube arrangement may be similar to that shown in Figures 2 and 3.

A modified form of the invention is shown in Figures 5 and 6, Figure 5 being a vertical view, partially in section of the gas removal section of a conversion vessel In and Figure 6 being a plan view taken along line 6-6 of Figure 5. In this form of the invention the gas collecting members take the form of inverted cups 10 having tapered roofs and being of rectangular and preferably square cross-sectional shape at their base. Each cup only covers a small portion of the vessel cross-sectional area and is supported a spaced distance above the partition 50 by means of a tube H which passes tightly through the partitions to terminate shortly therebelow in the gasspace 52 on its lower end and which passes through and is fastened tightly to the roof of the inverted cup on its closed upper end. One or more perforations 12 are provided in each tube at a position under the cup to communicate the cups with the interior of the tubes. The cups I0 are so spaced apart horizontally as to leave ample room for solid flow therebetween. The solid material passes from the column of contact material above the partition 50 downwardly through the gas space 52 through tubes 13 which are staggered horizontally between the tubes 1 I, as shown in Figure 6. The tubes II are braced on their upper ends by rods 14. The arrangement shown in Figures 5 and 6 wherein the cups are arranged on a square pattern is well adapted for vessels of rectangular cross-sectional shape. If the vessel is of circular cross-sectional shape that arrangement shown in Figures 7 and 8 is preferable. In the apparatus shown in Figures '7 and 8 the inverted gas collecting cups 80 have conical shaped roofs with cylindrical depending skirts. The cups are arranged in a pattern of spaced concentric circular rows. The central portion of the vessel is occupied by four cups 83 of somewhat smaller size than the others. Each cup is supported by a tube 8| which passes tightly through the partition 50. The cups communicate with the interior of the tubes 8! through the orifices 84 in the tubes. A plurality of tubes 85 depend from partition 50 for flow of contact material through the gas space 52. Other portions of the apparatus may be similar to those described in connection with the apparatus shown in Figures 2 and 3.

For operations wherein the rate of reactant flow through the conversion zone is very high, it isdesirable to provide more than one row of gas collecting members so as to prevent excessive agitation and boiling of the solid material at the surfaces of gas disengagement under the collecting members. Such an apparatus arrangement is shown in Figure 9 wherein there are provided a plurality of side by side, parallel vertical rows of vertically spaced collecting troughs 95, adjacent troughs in adjacent rows being offset vertically. A row of horizontally spaced vertical tubes 96 extends upwardly through the partition 50 and through all troughs in any given vertical row. The tubes 98 closed on their upper ends and perforated at locations along their length just under the roofs of the troughs through which they pass. Rods 81 serve to laterally brace the tubes at their upper ends. Baiiie plates 99 are connected to the lower ends of the tubes and slots 98 are provided in the sides of the tubes just above baflle plates 81 for egress of gas from the tubes. This arrangement deflects the high velocity gas flow from the tubes away from the surface of the bed of contact material 53 therebelow and also imparts a tangential direction of flow of the gas which aids in the settling of entrained particles. Rows of tubes I" depend from the partition 50 for solid flow to the bed 53 and gas outlet [9 is provided for gas withdrawal from gas space 52.

It has been found that when this construction is employed the orifices in any given tube 96 should be of progressively larger size for troughs at successively lower levels. The reason for this is that due to the resistance to flow of gas thnough the column below the uppermost level of troughs, there is a tendency for an excessive amount of gas to be collected by the uppermost troughs. By proper sizing of the oriflces at each level of troughs the rate of gas withdrawal from each level of troughs may be so limited as to prevent boiling of the column material up under any level of troughs. It has been found that the provision of about 12 to 15 inches from top to top of collecting devices in any verbe understood that the expressions gas collecting spaces and gas collecting devices as used in claiming this invention are employed in a broad sense as covering both inverted cups and inverted troughs.

It will be apparent that all of the above described modifications of this invention have certain important features in common. In all of the modifications there is provided within the lower section of the column of contact material in the conversion zone a plurality of uniformly spaced gas handling members adapted to collect gas from the column but to prevent gravity flow of solid material from the column into the gas handling member. Bame means is provided at a spaced vertical distance below these gas collecting devices adapted to provide a solid settling space and plenum chamber of substantially greater size than the gas spaces provided by the gas collecting devices and to provide confined passages for solid fiow from the column through the plenum chamber onto the bed of contact material maintained below the plenum chamber. Conduit means is provided extending from the plenum chamber separately to each gas collecting member or to each vertical row of collecting devices for the purpose of equalizing the pressure in all the gas collecting devices and for the purpose of providing passages for gas withdrawal from the gas collecting devices. Gas substantially free of solid particles is finally withdrawn from the plenum chamber.

' The method and apparatus of this invention may be employed in a wide variety of processes involving contact of gas with a column of particle-form solid material. The invention is particularly applicable to catalytic processes for the cracking conversion of liquid or vaporous hydrocarbon charges or both. In general such hydrocarbon conversion operations are conducted under temperatures within the range about 800 1''.

to 1100 F. Low pressures oi the order of tocharge is preheated to a temperature of the order of 500 F.-900 F. and all or part or the heat required for the conversion may be carried into the conversion zone in the catalyst.

It will be understood that the particular apparatus dimensions employed will vary depending upon the particular operation and operating conditions involved. In general the gas collecting devices should be of such size and number with respect 'to the rate of gas withdrawal from the conversion zone as to permit disengagement of gas from the solid column without causing the solid column surface to rise a substantial distance under the collecting devices. The plenum chamber should be of such size as to provide. more gas space than all the combined gas collecting devices so as to insure proper settling of the contact material particles.

As an example of a satisfactory apparatus construction for the conversion of fluid hydrocarbons in a vessel ofa-bout twelve feet diameter constructed as shown in Figure 2, a single row consisting of eleven gas collecting troughs was provided. The troughs were straight along their lengths, being made of different lengths to meet the contour of the circular vessel. The longest trough which extended across the center of the vessel measured just under twelve feet in length. The troughs measured about fourteen inches in height and nine and one-quarter inches in width and were spaced on twelve inch centers. The bases of the troughs 60 were positioned about sixteen inches above the partition 50. The solid flow pipes 5! were three inch tubes positioned in rows corresponding to the troughs, the tubes in each row being positioned on four and one-half inches centers. The tubes 5! extended below the partition 50 to a distance of about two feet. The gas flow tubes 6| were two and one-half inch diameter tubes positioned on 'four and onehalf inch centers under each trough. The above apparatus may be employed for a catalytic cracking operation wherein the rate of catalyst flow through the convertor is of the order of 50 to 100 tons per hour and the rate of charge of a petroleum gas oil vapor boiling within the range about 450 F. to 800 F. is of the order of 2000 to 5000 barrels per day (measured as a liquid at 60 F.). In such an operation wherein a synthetic gel-type catalyst was employed and suii'icient volume of column within the conversion zone was provided for a reactant space velocity of about 1.8 volumes of oil (measured at 60 F.) per hour per volume of catalyst column in the conversion zone, the eiiluent gaseous reaction products may contain of the order of 40% by weight 400 F. E. P. gasoline and lighter constituents.

It should be understood that the particular details of apparatus construction and of operation and the examples of application of this invention given hereinabove are-intended as exemplary and are not to be construed as limiting the scope of this invention except as it may be limited by the following claims.

I claim:

1. A method for conversion of fluid hydroca bons to lower boiling gaseous hydrocarbons in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined, elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a substantially compact column of downwardly flowing particles, introducing fluid hydrocarbons into the uppPr section of said zone and passing said hydrocarbons downwardly within said column to effect conversion to lower boiling gaseous hydrocarbons, collecting said gaseous products in a plurality of gas collecting spaces spaced apart within the lower section of said column, maintaining within a lower section of said zone a settling space, flowing the contact material in said column downwardly around said collecting spaces and passing contact material as at least one substantially compact confined stream from a level in said column below said ga collecting spaces through said settling space onto a substantially compact bed of said contact material below and exposed-to said settling space, withdrawing contact material from said bed at a controlled rate, passing the collected gaseous products from each of said gas collecting spaces as a confined stream to said settling space and withdrawing gaseous products from said settling space.

2. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbons in the presence oi! a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined, elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone, as a substantially compact column of downwardly flowing particles, flowing contact material from the lower end of said column as a plurality of spaced, confined, compact streams downwardly onto the surface of a bed of contact material maintained within a lower portion of said zone a spaced distance below the bottom of said column so as to establish a single gas space for solid settling around said confined streams and in.

open communication with said bed, withdrawing used contact material from said bed at a controlled rate, introducing heated fluid hydrocarbons at least partially in the liquid phase into the upper section of said conversiofr zone, passing said fluid hydrocarbons downwardly within said column to efiect conversion of said fluid ticles downwardly from each collecting zone as a confined stream to sai single settling space to permit settlingof entrained solid particles onto said bed belowesaid settling space and withdrawing the gaseous conversion products from said single settling space.

3. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbons in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined, elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a substantially compact column of downwardly flowing particles, flowing contact material from the lower end of said column as a plurality of spaced, confined, compact streams downwardly onto the surface of a bed of contact material maintained within a lower portion of said zone a spaced distance below the bottom of said column so as to establish a single gas space for solid settling around said confined streams and in open communication with said bed, withdrawing used contact material from said bed at a controlled rate, introducing heated fluid hydrocarbons into the upper section of said conversion zone, passing said fluid hydrocarbons downwardly within said column to eflfect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, bailling the solid flow in the lower section of said column, at a single level spaced substantially above the lower end of said column to create a plurality of horizon tally spaced apart gas collecting zones within said column from which zones gravity flow of solid material from said column is excluded, collecting the gaseous conversion products in said collecting zones,'passing the collected gas and any entrained solid particles downwardly from each collecting zone as a separate, confined stream to said single settling space to permit settling of entrained solid particles onto said bed below said settling space and withdrawing the gaseous conversion products from said single settling space.

4. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbons in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into theupper section of a confined, elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a substantially compact column of downwardly flowing particles, withdrawing contact material from the lower end of said column by subdividing the column into a plurality of confined components distributed uniformly across the cross-sectional area of said conflnedzone,

. the cumulative cross-sectional area of said components being substantially less than the crosssectional area of said zone so as to provide a single gas space having substantial cross-sectional area within said zone around said components, directing said components onto the surface of a substantially compact bed of said contact material maintained in the lower section of said conversion zone, withdrawing used contact material from said bed at a controlled rate, introducing heated fluid hydrocarbons into the upper section of said conversion zone, passing said fluid hydrocarbons downwardly within said column to efiect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, disengaging the gaseous hydrocarbons from the moving contact material and collecting said gaseous hydrocarbon products in a plurality of gas collecting spaces which collecting spaces are spaced apart and concentrically arranged across permit entrained solid particles to settle in said single gas space, and withdrawing gaseous products from said single gas space.

5. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbons in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined, elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a substantially compact column of downwardly flowing particles, flowing contact material from the lower end of said column as a plurality of spaced, confined, compact streams downwardly onto the surface of a bed of contact material maintained within a lower portion of said zone a spaced distance below the bottom of said column so as to establish a single gas space for solid settling around said confined stream and in open communication with said bed, withdrawing used contact material from said bed at a controlled rate, introducing heated fluid hydrocarbons into the upper section of said conversion zone, passing said fluid hydrocarbons downwardly within said column to effect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, bailling the solid flow in the lower section of said column at a plurality of locations at a plurality of levels all spaced substantially above the lower end of said column so as to create in the lower section of said column a plurality of horizontally spaced apart vertical rows of vertically spaced apart shielded gas collecting spaces from which gravity flow of contact material from said column is excluded, collecting said gaseous conversion products in said collecting spaces and passing the collected gas and any entrained solid particles downwardly from said collecting spaces as confined streams to said single settling space to permit settling of entrained solid particles onto said bed below said settling space and withdrawing the gaseous conversion products from said single settling space.

6. In a gas solid contacting vessel adapted for confining a substantially compact column of particle-form solid material therein an improved means for withdrawal of gas from said columnin said vessel which comprises: a substantially horizontal partition extending across said vessel at a level which is under the surface of said solid material column therein, a plurality of gas collecting members within said vessel a spaced distance above said partition, conduit means passing through said partition adapted to provide passage for solid material from a level spaced substantially below said gas collecting members to a level a spaced distance below said partition, conduit means for gas flow from under each of said gas collecting members to a location below said partition but above the lower extremity of said first named conduit means, and means to withdraw gas from said vessel at a level below said partition but means 13 above the lower extremity of said first named conduit means.

7. In a gas-solid contacting vessel adapted for I means within said vessel substantially spaced above said partition adapted to define a downwardly opening gas collecting space, conduit means for solid flowing passing through said partition terminating at its upper end a spaced distance below said baiiie means and at its lower end a spaced distance below said partition so as to provide a second gas space within said vessel immediately below said partition, conduit means for passage of gas from said gas collecting space into said second gas space and conduit means for withdrawal of gas from said second gas space.

8. In a gas-solid contacting vessel adapted for confining a substantially compact column of particle-form solid material therein an improved means for withdrawal of gas from said column in said vessel which comprises: means within said vessel for defining a plurality of uniformly spaced,

confined passages for solid material fiow through a vertical section of said vessel and for excluding solid flow from a substantial portion of the horizontal cross-sectional area of said vessel along said vertical section so as to provide a substantial single gas space for solid settling, which gas space is open to the portion of the vessel therebelow; at a spaced distance above said first named means within said vessel a plurality of horizontally spaced apart bafiles adapted to define a plurality of gas collecting spaces from which direct gravity fiow of material is excluded; means defining, a confined passage for gas flow from each of said gas collecting spaces to said single gas space for solid settling and means for withdrawal of gas from said single gas space.

9. A gas-solid contacting apparatus which comprises in combination: means defining a contacting chamber, means to introduce contact material to the upper section of said chamber, means to withdraw contact material from the lower section of said chamber, conduit means communieating the upper section of said chamber with the exterior, a plurality of uniformly spaced gas collecting members within said vessel below said contact material introduction means but above said contact material withdrawal means, means defining a single gas space occupying a substantial portion of the horizontal cross-sectional area of said vessel along a section thereof spaced a substantial distance below said gas collecting members and defining at least one confined substantially vertical passageway for contact material flow downwardly from a location in said vessel above said gas space and a substantial distance below said gas collecting members to a location below said single gas space, said single gas space being open to the portion of the vessel therebelow, conduit means defining a confined passage for gas flow from said gas collecting members to said single gas space and means to withdraw gas from said single gas space.

10, A hydrocarbon conversion vessel which comprises in combination: a substantially vertical vessel adapted to confine a reaction gas and a substantially vertical vessel adapted to confine a reaction gas and a substantially compact column of contact material, means to introduce contact material into the upper section of said vessel, means to withdraw contact material from the lower section of said vessel, means to introduce a fluid hydrocarbon reactant into the upper section of said vessel, a plurality of uniformly spaced apart gas collecting devices positioned at a single level within the lower section of said vessel, means spaced substantially below all of said collecting devices defining a single gas space occupying a substantial portion of the horizontal cross-sectional area of said vessel along a section thereof a spaced distance below said gas collecting devices and defining a plurality of spaced apart passages for contact material fiow downwardly from a single level in said vessel spaced below said collecting devices to a level below said single gas space, at least one separate downwardly extending conduit for gas flow from within each of said gas collecting devices to said single gas space, and means to withdraw gas from said single gas space.

11. A hydrocarbon conversion vessel which comprises in combination: a substantially vertical vessel adapted to confine a reaction gas and a substantially compact column of contact material, means to introduce contact material into the upper section of said vessel, means to withdraw contact material from the lower section of said vessel, means to introduce a fluid hydrocarbon reactant into the upper section of said vessel, a plurality of horizontally spaced apart gas collecting devices distributed uniformly across said vessel at a single level within the lower section thereof, said collecting devices being adapted to collect gas from the contact material column in said vessel but to prevent gravity fiow of contact material from said column thereinto, a partition across said vessel a spaced distance below said collecting devices, a plurality of uniformly distributed conduits for solid flow extending through said partition, said conduits terminating on their upper ends a substantial distance below said gas collecting devices and on their lower ends a substantial distance below said partition so as to provide a single gas space from which gravity fiow of contact material is excluded immediately below said partition, separate conduit means for passage of gas from within each of said gas collecting devices downwardly through the intervening portion of said vessel into said single gas space, and conduit means on said vessel for withdrawal of gas from said single gas space.

12. A hydrocarbon conversion Vessel which comprises in combination: a substantially vertical vessel adapted to confine a reaction gas and a substantially compact column of contact material, means to introduce contact material intothe upper section of said vessel, means to withdraw contact material from the lower section of said vessel, means to introduce a fluid hydrocarbon reactant into the upper section of said vessel, a plurality of horizontally spaced apart gas collecting devices distributed uniforml across said vessel at a single level within the lower section thereof, said collecting devices being adapted to collect gas from the contact material column in said vessel but to prevent gravity flow of contact material from said column thereinto; a partition across said vessel a spaced distance below said collecting devices. a plurality of uniformly distributed conduits depending from said partition for flow of solid material from locations just over said partition and spaced substantially below said collecting devices to a substantially single level within said vessel spaced substantially below said partition, for each of said gas collecting devices at least one substantially vertical conduit, closed on its upper end extending through the roof of said collecting devices and being fastened thereto and extending downwardly through said partition and being fastened thereto so as to serve as a support for said collecting device, said last named conduit terminating below said partition but above the lower ends of said conduits depending from said partition and said last named conduits having at least one hole therein positioned to communicate the interior of the conduits with the interior of said gas collecting devices, and means to withdraw gas from said vessel at a level below said partition but above the lower ends of the conduits depending from said partition.

13. An apparatus for conversion of fluid hydrocarbons in the presence of a compact column of downwardly flowing particle-form contact material which comprises in combination: a substantially vertical conversion vessel adapted to confine a fluid reactant and a column of contact material; means to introduce particle-form contact material into the upper section of said vessel; means to withdraw contact material from the lower end of said vessel; a partition extending entirely across said vessel within the lower section thereof; a plurality of uniformly spaced apart conduits for solid fiow depending from said partition and terminating a spaced distance therebelow so as to provide a single gas space within said vessel around the lengths of said conduits; a row of horizontally spaced apart, inverted gas collecting troughs extending across said vessel at a level within the lower section thereof a substantial vertical distance above said partition and a substantial distance below the upper ends of said conduits; a plurality of spaced tubes, open on either end, extending downwardly from a point in the gas space under each of said troughs through said partition and terminating in said single gas space and means to withdraw gas from said single gas space.

14. An apparatus for conversion of fluid hydrocarbons in the presence of a compact column of downwardly flowing particle-form contact material which comprises in combination: a substantially vertical conversion vessel adapted to confine a fluid reactant and a column of contact material, means to introduce particle-form contact material into the upper section of said vessel, means to withdraw contact material from the lower end of said vessel, a partition extending entirely across said vessel within the lower section thereof, a plurality of uniformly spaced apart conduits for solid flow depending from said partition and terminating a spaced distance therebelow so as to provide a single gas space within said vessel around the lengths of said conduits below said partition, a plurality of inverted collecting troughs within the lower section of said vessel a spaced distance above said partition and the upper ends of said depending conduits, said troughs being arranged in a plurality of spaced side by side vertical series of vertically spaced troughs, a plurality of vertical tubes passing through each trough of each series of troughs, and extending tightly through said partition to a level in the gas space therebelow, each of said tubes being closed on its upper end and being perforated to provide communication between the interior thereof and the space below each trough through which it passes, and means to withdraw gas from said single gas space,

15. An apparatus for conversion of fluid hydrocarbons in the presence of a compact column of downwardly flowing particle-form contact material, which comprises in combination: a substantially vertical conversion vessel adapted to conline a fluid reactant and a column of contact material, means to introduce particle-form contact material into the upper section of said vessel, means to withdraw contact material from the lower end of said vessel, a partition extending entirely across said vessel within the lower section thereof, a plurality of uniformly spaced apart conduits for solid flow depending from said partition and terminating a spaced distance therebelow so as to provide a single gas space within said vessel around the lengths of said conduits, a plurality of inverted, substantially horizontal gas collector troughs arranged in a plurality of substantially parallel vertically extending series placed side by side across said chamber, each of said troughs being disposed on a horizontal level intermediate the horizontal level of adjacent troughs of an adjacent series of troughs and the lowermost troughs being spaced a substantial distance above said partition and above the upper ends of said depending conduits, a plurality of vertical tubes passing through each trough of each series of troughs, and extending tightly through said partition to a level in the gas space therebelow, each of said tubes being closed on its upper end and being perforated to provide communication between the interior thereof and the space below each trough through which it passes, and means to withdraw gas from said single gas space.

16. A method for contacting gases with moving particle form solids comprising: passing particle form solids downwardly through a confined zone as a substantially compact bed of downwardly flowing particles, maintaining a second bed of said solids in a second confined zone below said first named bed and maintaining a settling space above said second bed, baffling the solid flow in the lower section of said first named bed to create a plurality of spaced gas collecting spaces within said bed in gas fiow communication with said bed, passing solids in at least one confined stream from a level in said first bed spaced below said gas collecting spaces onto the surface of said second bed, passing gaseous material downwardly within said first bed to contact said solids, collecting the contacted gaseous materials in said gas collecting spaces, passing the collected gaseous material and any entrained solid particles in confined streams from said gas collecting spaces to said settling space above said second bed to permit settling of solid particles onto said second bed, withdrawing gaseous material from said settling space and withdrawing solids from the lower section of said second bed at a controlled rate.

ERIC V. BERGSTROM.

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

UNITED STATES PATENTS Number Name Date 2,386,846 Dunham Oct. 16, 1945 2,409,596 Simpson et al Oct. 15, 1946 17 Certificate of Correction 18 Patent No. 2,458,498. January 11, 1949.

ERIC V. QERGSTROM It is hereby certified that errors appear in the printed specification of the abov numbered patent requiring correction as follows:

Column 13, line 12, claim 7, for the word flowing read flow;

lines

72 and 73, claim 10, strike out the words vertical vessel adapted to confine a reaction gas and a substantially; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 24th day of May, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oommissz'oner of Patents.