US2508993A

US2508993A - Method for conducting gaseous reactions in the presence of a moving particle form solid

Info

Publication number: US2508993A
Application number: US748578A
Authority: US
Inventors: Jr John A Crowley
Original assignee: Socony Vacuum Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1947-05-16
Filing date: 1947-05-16
Publication date: 1950-05-23
Anticipated expiration: 1967-05-23

Description

May23, 1950 J. A. CROWLEY JR 2,508,993

METHOD FOR CONDUCTING GASEOUSREACTIONS IN THE PRESENCE 0F A MOVING PARTICLE FORM SOLID Filed May 16, 1947 2 Sheets-Sheet l /6 43 J8 la J9 MEC/mman /3 l Com/from INVENTOR owaaawegwy May 23, 1950 Filed May 16,

J. A. CROWLEY muon Fox coNnucTING GAsEous PRESENCE 0F A MOVING PARTICLE FORM SOLID REACTIONS IN THE 2 Sheets-Sheet 2 WOZ/NG CHR/1455 lNVENTOR a ww Patented May 23, 1950 METHOD FOR CONDUCTING GASEOUS RE- ACTIONS IN THE PRESENCE F A MOVING PABTICLE FORM SOLID John Crowley, Jr., New York, N. Y., assigner to Socony-Vacnum Oil Company, Incorporated.

a corporation of New York Application May 16,1947, serial No. 743,573

' 19 claim. (cl. ias-52) This invention has to do with a method for conducting gaseous reactions in the presence of a particle form contact material vmoving through the reaction zone as a substantially compact column. The method of this invention is particularly adapted for conducting gaseous reactions which require reaction temperatures above those temperatures at which solid material can be Dractically conveyed in conventional conveyor equipment. Exemplary of such processes is the high temperature catalytic cracking conversion of hydrocarbons at temperatures of the order of 1000 F. to 1200 F. to high yields of aviation gasoline and C4 fractions. Another process is the conversion of propane to acetylene at temperatures of the order of 2300 F. in the presence of an inert solid material. Another process is the dehydrogenation of butene to di-oleilns at temperatures of the order of 1000*' F. to 1300 F. in the presence of a dehydrogenation catalyst such as chromic oxide on alumina. Still another reaction is the pyrolyss of pentene-2 to butadiene at temperatures of the order of 1200-1300 F. Another reaction is the preparation of thiophene and butadiene by reaction between n-butane and sulfur vapors at temperatures of the order of 900-1200 F. Another process is the manufacture of ethylene by the `cracking of heavier hydrocarbons such as gas oils or by the cracking of propane or ethane at temperatures of the order of l400 F.- 1800 F. In the case of all of these reactions the operation is carried out at relatively low pressures of the order of atmospheric to about 100 pounds per square inch gauge.

An important practical dilculty arises in attempting to conduct such processes as enumerated above in the so-called moving bed type of processes. Such moving bed type processes for proper operation require the use of a granular or particle form contact material as distinguished from powdered contact material and it is of the utmost importance in moving bed processes to limit the amount of catalyst attrition to fines to an absolute minimum. In order to attain this objective it has been found necessary in such systems wherein cyclic flow of the contact material is involved to utilize mechanical conveyors to complete the cyclic event. One of the most satisfactory types of mechanical conveyors for this purpose is the continuous bucket elevator which is adapted to transfer solid particles from one level to another with a minimum oi.' breakage and attrition of said solid particles. However, in processes of the type described hereinabove, the-required contact material temperatures are so high that attempts to mechanically convey the contact materials at such tempera- Vtures would result in failure and very rapid wear of the metal parts of the mechanical conveyor. It has been found unpractical to attempt to mechanically convey contact materials at the temperatures involved in most of the above described reactions. On the other hand to cool the contact material down before conveying and then to reheat the contact material again after conveying to render it suitable for use in the convertor results in a loss from the cyclic system of an uneconomically high amount of heat which renders the whole process unfeasible. 'I'he use of gas conveyors or gas lifts to transfer the contact material in such processes is also unfeasible because of the excessive amount of contact material attrition that inherently occurs in that type of conveying equipment.

A maior object of this invention is the provision of a method for conducting such processes as described hereinabove which method overcomes the above described dimculties.

Another object of this invention is the provision of a practical method for conducting reactions involving gaseous reactants in the presence of a mass of moving solid material particles at reaction temperatures above those at which it has been heretofore found practical to l convey solid particles.

Another object is the provision oi.' a practical continuous process for conducting high temperature gaseous reactions in the presence of a substantially compact column of movingsolid particles.

A specific object of this invention is the provision of an improved cyclic process for the high temperature conversion of saturated fluid hydrocarbons to ethylene containing products.

y Another specific object is the provision of an improved cyclic process for catalytic cracking conversion of petroleum fractions to gaseous products containing substantial amounts of hydrocarbons containing four carbon atoms in the presence of a moving mass of particle form catalyst.

These and other objects of this invention will become apparent from the following discussion thereof.

The invention may be most readily understood by reference to the attached drawings of which Figure 1 is an elevational view, partially in section,.of a system for conducting the method of this invention; and,

Figure 2 is a similar .view of a modiiled and preferred form of this invention. Both oi' these drawings are highly diagrammatic in form.

Turning now to Figure 1 there is shown an elongated vertical vessel I0, which may be supplied with contact material at its upper end through an elongated feed conduit II extending downwardly from a supply hopper I2. A contact material discharge conduit I3 bearing a throttling valve I4 is connected into the downwardly tapered bottom of vessel II). Above the discharge conduit I3 there are provided across the vessel Ill two vertically spaced apart horizontal partitions I5 and I6. The partition I5 has a plurality of uniformly spaced orices I1 therein. The partition I6 has a smaller plurality of orices I8 therein, positioned in horizontally staggered relationship with the orifices I1. The arrangement is such that the contact material flowing from the column thereof above partition I6 is split into a plurality of streams uniformly distributed over the vessel cross-section, which streams are then proportionately merged in steps until only a singie outlet stream in conduit I3 is provided. By this arrangement it is possible to withdraw con-l tact material uniformly from all portions of the vessel horizontal cross-sectional area to the single outlet I3. This invention is not to be construed as llimited to this arrangement and it is contemplated that any other arrangement adapted'to accomplish the same purpose may be substituted therefor. The vessel I0 is divided into four superposed chambers by means of vertically spaced horizontal partitions I9, and 2l positioned at intervals within the vessel. The chambers so formed are, reading downwardly, contact material surge chamber 22, heating chamber 23, conversion chamber 24, and cooling chamber 25. Uniformly

distributed tubes

26, 21 and 28 depend from partitions I9, 20 and 2| respectively for ow of contact material from each chamber to the chamber next below. The

tubes

26, 21 and 23 also serve to provide gas collecting spaces 29, 30 and 3| in the upper ends of

chambers

23, 24 and 25 respectively. Gas outlet conduits 32. 33 and 34 connect into the vessel shell at the levels of collecting spaces 29, and 3| respectively. Within the lower sections of

chambers

23, 24 and 25 there are provided rows of spaced, horizontally extending inverted

gas distributing troughs

35, 36 and 31 respectively. Only one trough in each row is visible in Figure 1. In a preferred form these troughs may have gable shaped roofs and they are open along their bottoms and closed by plates such as 8 on their ends. Gas may be supplied under troughs 35. 36 and 31 by through pipes 38, 33 and 4I! respectively which in turn connect outside the vessel to manifolds 4I, 42 and 43 respectively. Reactant charge may be supplied to manifold 42 through conduit 44 and gas may be supplied to manifolds 4I and 43 through conduits 45 and 46 respectively. Positioned alongside of the vessel I0 is a separate vertical reconditioning vessel 43. In the form shown the reconditioner is provided with a solid inlet chute 43 at its upper end and a solid outlet conduit 5I! on its lower end. A ilow throttling valve 5I is provided on conduit 5l. A gas inlet conduit 52 connects into the lower end of vessel 48 and may communicate within the vessel with suitable gas distributing devices (not shown). A gas outlet conduit 53 is provided near the upper end of vessel 43. Heat transfer tubes (not shown) supplied with uid through conduit 54 may be positioned within vessel 43. 'I'he heat exchange fluid may be withdrawn from the tubes through conduit 55. The type of reconditioner shown is one of several possible types which may be employed for operations in which the reaction process involves deposition of carbonaceous contaminant on a solid catalyst, which contaminant must be burned in order to regenerate the catalyst. The reconditioner may take other forms depending upon the particular reaction involved. In some reactions involving hydrocarbon conversion in the presence of inert refractory type particles, the contaminant burning step may not require close temperature control, in which case the heat transfer tubes may be omitted. In other processes, substantially no contaminant may be deposited on the contact mat` .n.l, in which case the reconditioner may simply take the form of apparatus adapted to permit an adjustment in the contact material temperature to render it suitable for reuse in the conversion zone. This temperature adjustment may be upward or downward depending upon whether the particular conversion reaction involved is endothermic or exothermic. It should be understood that the term reconditioning zone as employed herein in describing and in claiming this invention is intended to mean any zone properly adapted to suitably recondition the contact material, be it inert or catalytic, after its use in the conversion zone for reuse in the conversion zone. This reconditioning may involve the removal of a contaminant'deposit, the heating or cooling of the contact material or both burning oil of the contaminant and heating or cooling of the contact material to a level suitable for its subsequent introduction to the conversion zone or at least suitable for introduction into the conversion zone after it has passed through a heating zone of the type of zone 23 in Figure 1. A conveyor 53 is provided to transfer reconditioned contact material from vessel 48 to supply hopper I2 and another conveyor 53 is provided to transfer contact material from cooling chamber 25 to reconditloner 43. These

conveyors

58 and 53 are mechanical conveyors being driven by motors 50 and 6I respectively. Preferably they may be continuous bucket elevators.

As a typical example of the operation according to the method of this invention the high temperature catalytic cracking of petroleum gas oil fractions to products containing large amounts of aviation gasoline and of hydrocarbons containing four carbon atoms may be considered. In this operation the gas oil charge boiling within the range about 450 F.800 F. for example, may be introduced through conduit 65 to furnace 55 wherein it is vaporized and heated to a suitable temperature which is below that at which substantial pyrolytic cracking will take place at low pressures. For example, the gas oil may be heated to about 900 F. and passed through conduit 44 to manifold 42 and thence through pipes 39 to distributors 36 by which it is distributed into the lower section of a substantially compact column of gravitating catalyst `particles maintained within conversion chamber 24. The catalyst may consist of particles' of 4 to 16 mesh size, by Tyler standard screen analysis, for example. These particles may partake of the nature of a synthetic silica-alumina gel, for example. The catalyst may be introduced into the upper end of chamber 24 via tubes 21 at a temperature suiliciently high to supply the endothermic heat of hydrocarbon conversion without itself being cooled to a temperature below the desired conversion temperature range. For this type of reaction the desired reaction temperature range may be of the order of about l000 F. to 1200* F. and the drop in catalyst teml 5 perature in the conversion zone may vary from about 50 to 200 F. depending upon the particular operating conditions and severity of the reaction. For example, the catalyst may enter chamber 24 at about 1200 F. and leave chamber 24 through tubes 28 at about 1100 F. The hydrocarbons are converted to gaseous products containing substantial amounts of aviation gasoline and C4 hydrocarbons, which are withdrawn from the conversion zone through conduit 33. It should be understood that the word gaseous" as used herein in describing and in claiming this invention is used in the broad sense as meaning material existing in the gaseous phase under the particular conditions of temperature and pressure involved regardless of the normal phase of that material under ordinary atmospheric conditions. The used catalyst bearing a, carbonaceous" contaminant deposited during the hydrocarbon conversion is then purged substantially free of gaseous reactants by means of a suitable inert purging gas such as steam or ilue gas introduced through conduit 85, manifold 85 and pipes 81 to distributor 88 Within the lower section oi chamber 24. The purged catalyst then passes as a substantially compact column downwardly through cooling chamber 25 wherein it is cooled by a suitable inert heat exchange gas which is introduced under distributors 31 from conduit 46 ai a temperature substantially below the ternperature in zone 24. The heat exchange gas should be substantially inert under the condition of its use to reaction with the hydrocarbon reactants. Steam, flue gas, CO: or Na are examples. The heat exchange gas flows upwardly through the column in the zone 25 countercurrently to the catalyst ow and the rate of gas flow is controlled so that the catalyst upon reaching the lower end of chamber 25 has been cooled to a temperature at which it may be practically mechanically conveyed.' It will be understood that the expression,a temperature at which it may be practically mechanically conveyed as used in the above sentence and as similarly used in claiming this invention, is intended to mean a temperature at which the contact material may be mechanically conveyed in mechanical conveyors adapted for transfer of the solids without excessive attrition thereof without frequent mechanical failure of the working elements of the conveyor because of the high temperatures involved. It has been found that mechanical conveyors, for example continuous bucket elevators, cannot be expected to practically handle contact material at temperatures above about 1100 F. without frequent failure, and that preferably the contact material temperature should be below about 1000o F. In the present example the catalyst may enter cooling zone 25 at about 1100 F. and be cooled therein to about 950 F. at which temperature the catalyst is withdrawn from vessel through conduit I3 at a suitable rate controlled by valve I4. The catalyst is then mechanically conveyed to reconditioner 48 which in this instance is a regenerator wherein it moves downwardly as a compact column while being subjected to contact with air or oxygen to burn oif the contaminants. A suitable heat exchange fluid is passed through heat transfer tubes within vessel 48 so as to limit the temperature of the catalyst below a heat damaging level and so as to provide a regenerated catalyst at conduit 50 which may be practically mechanically conveyed. The heat damaging temperature is the level above which the catalyst will suffer permanent substantial impairment in its catalytic enectiveness for the particular reaction involved. 'I'he heat damaging temperature will vary depending upon the nature of the contact material involved being above about 1150 to 1250 F. for many clay catalysts and above about 1350 F. to about 1500 F. for synthetic silica-alumina gel catalysts. In the present example the catalyst containing only about 0.1% to .8% by weight of residual carbon is mechanically conveyed by conveyor 58 to hopper I2 at a temperature of the order of 950 F. The regenerated catalyst then passes downwardly through leg II to surge zone 22 and then through heating chamber 23 wherein it moves as a substantially compact column. The heat exchange gas from cooling chamber 25 passes via

conduits

34, 15 and 18 to a conventional line burner 1|, supplied with fuel at 12 and air at 13 and then via conduits 14 and 45 to distributor 35 in chamber 23. The gas then passes upwardly through the column in chamber 23 transferring to the catalyst substantially all the heat picked up by the gas from the catalyst in cooling chamber 25. The heat exchange gas then passes from chamber 23 ateabout 950 F. through conduit 32 to blower 80 by which it is forced'through conduit 45 back into the cooling chamber 25. Since the catalyst temperature decreased somewhat in the conversion chamber 24 due to the heat required for the reaction, that amount of heat is still missing in the catalyst in chamber 23 even after transfer thereto of all the heat picked up in zone 25 by the heat exchange gas. To make up for this heat of hydrocarbon conversion. the heat exchange gas is heated a, controlled amount in line burner 1I so that the contact material in zone 23 may be heated again to tle desired reactor inlet temperature of 1200 F. (in this example) by the time it reaches the bottom of heating chamber 23. In those cases wherein the reaction in chamber 24 is exothermic instead of endothermic, for example polymerization reactions, it is then desirable to cool the heat exchange gas an amount approximately equal to the heat released in the convertor. In such cases the heat exchange gas may be conveniently steam which instead of being heated in line heater 1|, is passed via conduit 18 to spray cooler 11 wherein it is cooled by a water spray introduced at 18. The excess steam produced in cooler 11 or the excess flue gas and nitrogen produced by line burner 1| may be bled from the' closed cyclic heat exchange gas system through vent |52. It will be apparent that by proper control of the rate of heat exchange gas cyclic flow (using bypass |54) and by proper adjustment of its temperature at line cooler 11 or line heater 1|, the desired amount of heat may be transferred from catalyst in cooling zone 25 to catalyst in heating zone 23, while maintaining the gas inlet temperature to the catalyst cooling zone 25 at 46 substantially constant. It is desirable to control the gaseous pressures in

chambers

23 and 25 slightly higher than that in chamber 24. This may be accomplished by conventional methods, for example. when the Operating pressure in conversion zone 24 is about 10 pounds per square inch gauge. the pressure in

chambers

23 and 25 may be maintained by means of differential pressure control instruments operating valves-|50 and IM on conduits 3 4 and 32 respectively or van. |53 on vent |52 at a pressure of about 10i/ pounds per square inch gauge. In this manner the

chambers

23 and 25 serve not only as catalvst cooling and heating chambers but also as seal zones, to prevent escape of hydrocarbon reactants from either end oi.' the conversion zone 24.

In the case of reactions wherein the endothermic heat required for the reaction in the conversion chamber is very great, it is preferable to conduct the process of this invention in the manner shown in Figure 2. In Figure 2 there are shown two superposed vessels 90 and 9|, through which thecontact material ilows serially, and a mechanical conveyor 92 to convey the contact material from the outlet conduit 93 of the lower vessel 9| to the solids inlet conduit 94- at the top of the upper vessel 90. If desired a catalyst surgeA chamber (not shown) may be incorporated in conduit 94 or positioned above the top of vessel 90 as shown at 22 in Figure l to permit greater flexibility to the operation. The vessel 90 is dlvided into an upper heating chamber 95 and a lower reconditioning chamber 96 by horizontal partition 91 positioned thereacross. Tubes 90 depend from partition 91 for flow of contact material from chamber 95 to chamber 96 and to provide a gas collecting space 99 in the upper end of chamber 96. A similar gas collecting space is provided within the upper end of chamber 95 by the downward extension of solid inlet 94 within the chamber 95 a short distance below the upper end thereof. Gas outlet conduits |0| and |02 are provided on the shell adjacent spaces 99 and |00 respectively. A row of gas distributor troughs |03 supplied by pipes |04 from manifold |05 and conduit |06 is provided within the lower section of chamber 95 and a similar row of troughs |01 supplied by pipes |06 from manifold |09 and conduit ||0 is positioned within the lower section of chamber '96.` Contact material passes from the lower end of vessel 90 through conduit |50 bearing throttling valve to the upper end of vessel 9|. Vessel 90 is divided by horizontal partitions ||2 and ||3 into an upper seal chamber ||4, an intermediate conversion chamber and a lower cooling chamber ||6. Tubes and ||3 depend from partitions ||2 and I|3 respectively for contact material ilow. A gas outlet ||9 connects into the shell of vessel 9| opposite the gas collecting space |20 in the upper end of chamber ||5 and a gas outlet conduit 2| connects into the shell opposite gas collecting space |22 in the upper end of cooling chamber ||6. Reactant distributing troughs |23 are provided across the lower section of chamber i|5 and a row of purge gas distributing troughs |24 is also provided within chamber 5 below the troughs |23. The troughs |23 are supplied with reactant fluid through pipes |25 which connect into manifold |26, in turn supplied by conduit |21. The troughs |24 are supplied with gas from conduit |20 via manifold |29 and pipes |30. A similar row of troughs |3| supplied from conduit |32 via manifold |33 and pipes |34 is provided within the lower section of cooling chamber i6. A blower |35 is provided to cyclically circulate heat exchange gas through the cooling chamber I i6 and heating chamber 95.

As a typical example of the operation according to the method of this invention, the process of ethylene manufacture by the high temperature cracking of ethane may be considered. In this operation a particle form solid refractory material, such as fused alumina, mullite or zirkite, for examples, which material is substantially inert to the reacants may be: employed. Generally the particle size range should fall 'within the range 0.006 to 1.0 inch and preferably within the range 0.03 to 0.5 inch average diameter. The solid material is introduced into the upper end of vessel 9| at a temperature of the order of l'150-1800 F., for example. Ethane which may be preheated in a conventional external heater to a suitable temperature of the order of 500 to 1000 F. for example may be introduced, at a pressure of about 5-20 pounds per square inch for example,through conduit |21, to manifold |26 and thence vla pipes |25 to distributor |23 in the conversion chamber H5. The ethane to which steam may be added in controlled amounts, if desired, passes upwardly through the column of contact material in chamber ||5 so as to be converted to gaseous ethylene containing products which are withdrawn at i9. If desired an initial quench may be effected by spraying water into the eilluent gas either in space |20 in conduit ||9. Perforated pipes are provided in space |20 for that purpose and are supplied with quench liquid from header |60. The products are then nally quenched to a temperature usually at least below about 900 F. in a suitable external apparatus (not shown). The rate of contact material ow may be controlled by valve |40 on conduit 93 so as to adjust the drop in contact material temperature as it passes through chamber ||5 to any set amount. In the present example the rate of contact material iiow may be controlled so that the contact material passing through tubes ||6 to chamber 6 exists at about 1500 F. The contact material may be purged by steam or iiue gas introduced at |28 to distributor |24 before it is withdrawn from chamber H5. In chamber ||6 the contact material is cooled by direct contact with gas introduced from conduit |32 to distributors 3|. The contact may be cooled in chamber ||6 from an inlet temperature of about 1500 F. to an outlet temperature of about l100 F., for example, and then be mechanically conveyed by mechanical conveyor 92 to conduit 94 supplying the heating chamber 95. In heating chamber 95 the contact material is reheated from about 10.90 F. to about 1490 F. by heat exchange gas leaving chamber ||6 at about 1500 F. and passing through conduits |2| and |4| to inlet |06 and thence into the distributor |03 in chamber 95. The gas after transferring its heat to the contact material in chamber 95 then passes at about 1100 F. through conduits |02 and |42 to blower |35 by which it is forced back into chamber |I6. The rate of gas flow may be controlled by controlling the rate of speed of the blower |35 or by other suitable means such as .by use of bypass |43 so as to accomplish the desired transfer of heat from cooling chamber I6 to heating chamber 95. It will be understood that depending upon the rate of gas flow the temperature differentials between the gas leaving zones 95 or ||6 and the entering solids may be somewhat greater or less than those given in the above example. The contact material, after being so heated in zone 95, may Pass to reconditioning chamber 96 at about 1500 F., for example. As it passes through chamber 96, the contact material may be heated by means of a suitable hot gas introduced through conduit |09 to distributor |01 to a temperature of about 1750-1800 F. and then it may be returned via conduit ||0 to the vessel 9| for reuse. If desired the heating in chamber 96 may be accomplished by burning of a gaseous fuel introduced from conduit by air introduced at H0 within the column in chamber 90. On the other hand often a certain amount oi' carbonaceous material may be deposited on the contact material during the hydrocarbon conversion reaction in chamber `I I5, and the contaminant may be burned'in chamber 96 to supply part or all of the required heating to be accomplished therein. The cyclic system may be maintained at constant temperature levels in the various zones by proper adjustment of the operation of reconditioner 06. Added flexibility may be provided by provision of a small heat exchanger on conduit Ill or in a surge chamber for` contact material positioned -above zone 95 or below zone IIS. A suitable seal gassuch as steam or ilue gas may be introduced into seal chamber III through conduit |46 at a suicient rate to maintain a gaseous pressure in chamber lll above that in chambers 96 and H5 thereby preventing interflow of gas therebetween.

The system shown in Figure 42 may also be employed for the same type of reaction described in connection with Figure 1. In this case the heating chamber 95 may be positioned as shown or it may be positioned vertically between chamber $6 and the vessel 9|. In the latter case by proper control ofthe inert gaseous pressure in chambers 95 and IIB, the need for seal chamber III may be eliminated, if desired.

It will be apparent from the above discussion that the method of this invention permits the conducting of gaseous reactions in the presencev of a moving particle form solid material at very high reaction temperatures without the necessity of subjecting the solid conveying equipment to the high reaction temperatures. Inasmuch as it is usually undcmrable to convey solid materials of this type in mechanical conveyors, bucket elevators, for vexample at temperatures in excess of about 1100 F., this feature permits the conducting of a large number of reactions in a continuous moving column type operation, which reactions heretofore could not be so conducted. Moreover this advantage is accomplished without the loss of any heat from the cyclically moving catalyst stream. Inasmuch as such processes on a commercial scale involve the circulation of about 50 to 400 tons of contact material per hour. the large amount v of heat saved by the use of the cyclic gaseous heat exchange system involving substantially no gas reject is a highly important factor. For many operations the amount of heat -recovered by burning contaminants in the reconditioning zone isI suiilcient to balance the heat required y for endothermic hydrocarbon conversions. Such` operations when conducted by the method described hereinabove become substantially thermally independent and self-sustaining. Moreover, there is very little cooling load involving the use of expensive heat transfer tubes.

It will be understood that the dimensions of the apparatus employed, the rates of reactant and solid flow, and the type oi solid material and heat exchangev gas employed are subject to wide variation depending upon the particular process to which this invention is applied. In

general, the reaction zone should be of such size as will permit the proper time of reactant contact with the suitable solid material therein for any given process. The contact material heating and cooling zones need only be of suiiicient size to permit the desiredy amount of gas-solid heat transfer. Due to the very high co-eillcients of .heat transfer between gases and solid when passed in direct contact relationship in the manner described hereinabove, the heating `and cooling zones may be of relatively small size, and of very simple and economical construction. In operations wherein very high volumetric gas throughput rates are required in the heating and cooling zones, these zones may be of somewhat larger cross-sectional area than the reaction zone therebetween in order to insure adequate gas throughput capacity without interference with the solid iiow.

The reactant space velocityin the conversion zone will of course vary depending upon the particular operation involved. Where petroleum gas oils are to be converted to products containing high amounts of aviation gasoline and four carbon atom hydrocarbons in the manner described in the example given hereinabove in connection with Figure l, the oil space velocity may vary from about 0.5 to 5.0 volumes oi oil charge (measured as a liquid at 60 F.) per hour per volume of catalyst in the conversion zone (measured as a substantially compact flowing column). The catalyst to oil charge ratio to the convertor in such an operation may -fall within the range about 1 to10 parts by weight of catalyst per part by weight of oil charged. In the case of the example considered hereinabove in connection with Figure 2, the solid throughput amounting to about 5 to l5 pounds of solid per pound of ethane charge is satisfactory. The volume of the reaction zone 24 should be such as to provide a reactant residence time of about 1.0 to 1.7 seconds.

The type of solid material used may vary from an inert solid such as corhart material, a fused alumina, which may be used for ethylene manufacture to an adsorbent type catalytic material which may be used for catalytic dehydrogenation reactions and for catalytic cracking reaction. Such catalytic materials may take the form of natural or treated clays, bauxites, inert carriers containing deposited metallic oxides such as deposits of the oxides of molybdenum, chromium or tungsten, or certain synthetic associations of silica, alumina or silica or alumina to which small percentages of othex` materials vsuch as metallic oxides may be added for special purposes. In general, it has been found that the particle size of such contact materials should fall broadly within the range about .006 to 1.0 inch average diameter and preferably within the range about 0.03 to 0.5 inch average diameter. It should be understood that the expression suitable particle form contact material as used in describing and in claiming this invention is used in a sense sufllciently broad to cover either so-called catalytic or non-catalytic materials which may be found suitable for the particular reaction involved. The term is to be considered as limited, however, only to those solid materials which have physical and chemical characteristics making them suitable for the particular process involved. Thus, for example solids, which would enter substantially into the main reaction or which would be decomposed or otherwise damaged under the reaction conditions involved, are vnot intended to be included in the term.

The expression suitable heat exchange gas" as used in describing and in claiming this invention is intended to mean a gas capable of carrying heat into the heating -zone and giving it up by ticular process involved. Thus, a gas used for any particular reaction process which would undergo an undesirable reaction under the conditions in the reaction zone or which would injure the solid material or reaction vessel is not intended to be included within the meaning of the above expression.

In the claiming of this invention the expressions suitable conversion temperature" and range of suitable conversion temperatures are intended to mean a temperature or range of temperatures which are suitable for conducting the particular reaction involved at a practical rate and to practical yields of the desired products.

It should be understood that the foregoing description of the method of this invention and examples of its applications and of the apparatus to which it may be applied are merely exemplary in character and are not intended to limit the scope of this invention except as it is limited in the following claims.

I claim:

1. A method for conducting thermo-chemical conversions of fluid reactants at controlled elevated temperatures in the presence of a suitable moving particle-form solid contact material which comprises: contacting said duid reactants at a suitable elevated conversion temperature with a substantially compact column of downwardly moving solid particle-form contact material in a confined reaction zone to effect said conversion of said reactants, withdrawing iluid conversion products from said reaction zone, withdrawing used contact material from said reaction zone and passing it as a substantially compact column through a conned cooling zone, introducing a suitable heat exchange gas into said column in said cooling zone at a temperature substantially below that oi said contact material entering said coolingzone and passing said gas through said column in said cooling zone to cool the contact material substantially below the temperature in said reaction zone, passing the cooled contact material from said cooling zone through a separate reconditioning zone wherein it is treated to render it suitable for reuse in said reaction zone, passing the reconditioned contact material to a heating zone and passing it through said heating zone as a substantially compact column, withdrawing said heat exchange gas from said cooling zone and passing it through said column in said heating zone so as to transfer heat removed from said contact material passing through said cooling zone back to said contact material passing through said heating zone, withdrawing the resulting cooled heat exchange` gas from said heating zone and returning it tc said cooling zone.

2. In a process for conversion of duid hydrocal-bons in the presence of a moving particleform contact material at elevated temperatures which are substantially above those at which said contact material may be practically handled in mechanical conveying equipment, wherein said contact material is passed through a cyclic path of travel in which it passes through a conversion zone wherein it ilows as a substantially compact column while being contacted with iiuid hydrocarbons to etect the conversion thereof and through a reconditioning zone wherein it conveyed, and before its return to said conversion zone through a heating zone as a substantially compact column while heating it therein, said heating zone being a separate zone in said cyclic path of travel in addition to said cooling, reconditioning and conversion zones; passing a suitable heat exchange gas as a cyclically moving stream through the column of contact material in said cooling and heating zones to eiect the cooling of said contact material in said cooling zone and to effect the transfer of the heat removed from said contact material in said cooling zone to said contact material moving through said heating zone so as to accomplish said aforesaid heating therein, and adjusting the heat content of said cyclically moving stream of heat exchange gas at a point in its cycle outside of said heating and cooling zones to maintain the gas inlet temperature to said cooling zone substantially constant.

3. In a continuous cyclic process for hydrocarbon conversion at elevated temperatures wherein a particle-form contact material is passed continuously through a cyclic path of travel which includes a conversion zone wherein it is contacted with iluid hydrocarbons at elevated temperatures to eiect the conversion thereof, a mechanical conveying zone in which is mechanically conveyed from a low level tc a higher level and a reconditioning zone in which it is treated to render it suitable for reuse in said conversion zone, the improvement which comprises; passing said contact material as a substantially compact gravitating column through a separate cooling zone at a location in its path of travel prior to its entrance into said mechanical conveying zone, passing a suitable inert heat exchange gas through said column in said cooling zone to eect a su'lcient removal of heat from said contactmaterial to lower its temperaturer to a level at which it may be practically mechanically conveyed, and passing said contact material as a substantially compact gravitating column through a heating zone at a iiows as a substantially compact column while being contacted with a suitable reconditioning huid to at least partially recondition it for reuse location in its cyclic path of travel after it has been mechanically conveyed and before it is returned into said conversion zone, said heating zone being a. separate zone in said cyclic path of travel in addition to said cooling conversion and reconditioning zcnes, passing the heat exchange gas from said cooling zone through said column in said heating zone under conditions controlled to effect transfer to the contact material therein at least a substantial part of the heat removed from the contact material in said cooling zone, and returning the heat exchange gas to said cooling zone.

4. A method for conversion of fluid hydrocarbons at elevated temperatures above about 1000" F. in the presence of a moving particleform contact material which comprises; contacting said iiuld hydrocarbon reactants at a suitin said conversion zone and in which path of able elevated conversion temperature which is 13 above about 1000 F. with a substantially compact column of downwardly moving solid particle-form contactrmaterial in a conned reaction zone to effect said conversion of said reactants, withdrawing fluid conversion products from said reaction zone, withdrawing used contact material from said reaction zone and passing it as a substantially compact column through a conned cooling zone, introducing a suitableheat exchange gas into said column in said cooling zone at a temperature substantially below that of said contact material entering said cooling zone and passing said gas through said column in said cooling zone to cool the contact material to a temperature within the range about 700 F. to 1100 F., mechanically conveying the cooled contact material to a regeneration zone, passing said contact material through said regeneration zone as a substantially compact col umn while contacting it with an oxygen containing gas to burn off therefrom carbonaceous contaminant, passing the regenerated contact material through a heating zone as a substantially compact column, passing said heat exchange gas from said cooling zone through said column in said heating zone to transfer to said contact material the heat removed by said gas from the contact material in said cooling zone returning the gas from said heating zone to said cooling zone, and flowing the heated contact material from said heating zone to said conversion zone.

5. A continuous process for conversion of uid hydrocarbons at elevated temperatures in the presence of a suitable moving particle-form contact material which comprises: passing said contact material cyclically in a closed path of travel which includes a conversion zone wherein it moves downwardly as a substantially compact column and is contacted at a suitable elevated conversion temperature with a fluid hydrocarbon charge to effect the conversion thereof with resultant deposition of carbonaceous material on said contact material, through a burning zone wherein the carbonaceous material is burned to raise the temperature of said contact material so as to supply thereto heat for said hydrocarbon conversion, and through at least one mechanical conveying zone wherein it is mechanically conveyed from a given level to a higher level; passing the cyclically moving contact material through a cooling zone as a substantially compact gravitating column at a point in its cyclic path of travel after the conversion zone and before at least one conveying zone, passing a suitable inert heat exchange gas through said contact lmaterial column in said cooling zone under conditions controlled to cool said contact material to a temperature within the range about 700 F. to ll F., passing the contact material asa substantially compact gravitating column through a conned heating zone at a point in its cyclic path of travel after at least one conveying zone and before it passes to said conversion zone, said heating zone being a separate zone in said closed path of travel in addition to said conversion, burning, cooling and mechanical conveying zones, passing said heat exchange gas from said cooling zone through the column in said heating zone under conditions controlled 'to effect transfer thereto approximately the amount of heat removed thereby from said cooling zone and returning the heat exchange gas after passage through said heating zone to said cooling zone.

6. A method for conducting thermochemical conversions of uid reactants at controlled elevated temperatures in the presence of a moving particle-form contact material which comprises: passing a suitable heated contact material as a substantially compact column of gravitating particles through a conned reaction zone in contact with iluid reactants at a temperature suitable for effecting the desired conversion of said reactants, withdrawing iluid reaction products from said zone, withdrawing used contact material from the lower section of said zone substantiallv separately of said iluid'products and flowing said used contact material by gravity to a confined cooling zone, passing said used contact material downwardly through said cooling zone as a substantially compact column, passing a suitable heat exchange gas upwardly through said column in said cooling zone under such conditions as to cool said contact material to a level at which it may be practically mechani- 'cally conveyed, mechanically conveying the cooled contact material to a levelsuitable for introduction thereof into a confined reconditioning zone, passing said contact material downwardly through said reconditioning zone as a substantially compact column while subjecting it to a treatment to render it suitable for reuse in said conversion zone, maintaining a coniined heating zone at a level above said conversion zone, passing reconditioned contact material-to said heating zone, passing the contact material as a substantially compact column downwardly through said heating zone, passing said heat exchange gas from said cooling zone upwardly through said column in said heating zone to transfer to said contact material moving therethrough the heat removed by said gas from said cooling zone and maintaining the temperature of the contact material entering said heating zone suiciently below that of the contact material entering said cooling zone to insure said transfer of heat between said zones, returning the heat exchange gas to said cooling zone and flowing the heated contact material from said heating zone into said conversion zone.

7. A method for conducting thermochemical conversions of iluid reactants at controlled elevated temperatures in the presence of a moving particle-form contact material which comprises: passing a suitable heated contact material as a substantially compact column of gravitating particles through a conned reaction zone in contact with iiuid reactants at a temperature suitable for eiecting the desired conversion of said reactants with a resultant change in the contact material temperature due to the heat of the reaction, withdrawing iluid reaction products from said zone, withdrawing used contact material from the lower section of said zone substantially separately of said fluid products and flowing said used contact material by gravity to a coniined cooling zone, passing said used contact material downwardly through said coolingy zone as a substantially compact column while cooling it to a temperature at which it may be practically mechanically conveyed, mechanically conveying the cooled contact material to a level suitable for introduction thereof into a confined reconditioning zone, passing said contact material downwardly through said reconditioning zone as a substantially compact column while subjecting it to a treatment to render it suitable for reuse in said conversion zone, maintaining a confined heating zone at a level above said conversion attacca i8 sono, passing reconditioned contact material to said heating zone, passing the contact material as a substantially compact column downwardly through said heating zone, passing a suitable heat exchange gas cyclically through the columns of contact material in said cooling and heating zones to eiect the contact material cooling in said cooling zone and to transfer at least a substantial portion of the heat removed from the contact material moving through said cooling zone to the contact material moving through said heating zone and maintaining the temperature of the contact material entering said heating zone sufllciently below that of the contact material enteringysaid cooling zone to insure said transfer of heat from said cooling zone to said heating zone, adjusting the temperature of said cyclically moving heat exchange gas at a location in its cyclic path of travel outside of said cooling and heating zones in a direction opposite to that of the temperature change of the contact material passing through said conversion zone and in an amount sumcient to counteract said contact material temperature change and to maintain a substantially constant gas inlet temperature to said cooling zone, and flowing the heated contact material from said heating zone to said conversion zone.

8. A method for conducting an endothermic conversion of iluid hydrocarbon reactants at controlled elevated temperatures in the presence of a moving particle-form contact material which comprises: introducing a suitable particleform contact material into the upper section of a conilned conversion zone at an elevated temperature suitable for supporting said endothermic hydrocarbon conversion, passing said contact material as a substantially compact column downwardly through said conversion zone, passing huid hydrocarbon reactants through said column to eilect said endothermic conversion thereof thereby reducing the temperature of said contact material and causing deposition oi' carbonaceous material thereon, withdrawing iluid conversion products from said zone, separately withdrawing used contact material from the lower section of said conversion zone, ilowing said used contact material as a substantially compact column downwardly through a confined cooling zone while cooling it therein to a temperature at which it may be practically mechanically conveyed, maintaining a conilned burning zone separate from said conversion zone, mechanically conveying the cooled contact material to a location suitable for its introduction to said burning zone, passing said contact material as a substantially compact column downwardly through said burning zone while contacting it with a combustion supporting gas to burn off said contaminant, removing at least a substantial portion of the heat liberated by said burning from the contact material, passing the reconditioned contact material to a mechanical conveying zone at a temperature at which it may be practically mechanically conveyed, maintaining a coniined heating zone above said conversion zone, mechanically conveying said reconditioned contact material to a location suitable for its introduction into said heating zone, passing the contact material downwardly through said heating zone as a substantially compact column, passing a suitable gaseous heat exchange medium cyclically through said columns in said cooling and heating zones to cool said contact material .in said cooling zone as aforesaid and to transfer the heat removed from said contact material in said cooling zone to the contact material in said heating zone, adding heat to said heat exchange medium at a location in its cyclic path oi' flow outside of said heating and cooling zones and prior to its entry into said heating zone in sufncient amount to substantially compensate for the amount` o! heat removed from said contact material in said conversion zone and ilowing the heated contact material from said heating zone to said conversion zone.

9. A method for conducting an endothermic conversion of fluid hydrocarbon reactants at controlled elevated temperatures in the presence of a moving particle-form contact material which comprises: introducing a suitable particle-form contact material into the upper section of a confined conversion zone at an elevated temperature suitable for supporting said endothermlc hydrocarbon conversion without said contact material being cooled below about 1100' F., passing said contact material as a substantially compact column downwardly through said conversion zone, passing iiuid hydrocarbon reactants through said column to eil'ect said endothermic conversion thereof thereby absorbing heat from said contact material and causing deposition of carbonaceous material thereon, withdrawing fluid conversion products from said zone, separately withdrawing used contact material from the lower section of said conversion zone, flowing said used contact material as a substantially compact column downwardly through a coniined cooling zone while cooling it therein to a temperature below about 1100 F., maintaining a coniined burning zone separate from said conversion zone, mechanically conveying the cooled contact material to a location suittable for its introduction to said -burning zone. passing said contact material asa substantially compact column downwardly through said burning zone while contacting it with a combustion supporting gas to burn off said contaminant, removing at least a substantial portion of the heat iiberated by said burning from the contact material, passing the reconditioned contact material at a temperature below about 1100 F. to a mechanical conveyor, maintaining a conilned heating zone above said conversion zone, mechanically conveying reconditioned contact material to a location suitable for its introduction into said heating zone, passing the contact material downwardly through said heating zone as a substantially compact column, passing a suitable gaseous heat exchange medium cyclically through said columns in said cooling and heating zones to cool said contact material in said cooling zone as aforesaid and to transfer the heat removed from said contact material in said cooling zone to the contact material in said heating zone, iiowing the heated contact material from said heating zone to said conversion zone to complete a cyclic path of contact material stream travel, adding sensible heat to the cyclically moving stream of contact material at at least one location in its path of travel to compensate for the heat absorbed by the reaction in said conversion zone and maintaining the temperature of the contact material entering said heating zone suficiently :below that of the contact material entering said cooling zone to insure said transfer of heat from said cooling to said heating zone by said heat exchange gas.

ing particle-form adsorbent catalytic contact material at temperatures above those at-which said contact material may be practically mechanically conveyed which process comprises: introducing a suitable particle-form contact material into the upper section of a connned conversion zone at an elevated temperature suitable for supporting said endothermic hydrocarbon conversion, which temperatures are above about 1000 F., passing said contact material as a substantially compact column downwardly through said conversion zone, passing fluid hydrocarbon reactants through said column to eiect said endothermic conversion thereof thereby causing deposition of carbonaceous material on the contact material, withdrawing fluid conversion products from said zone, separately withdrawing used contact material from the lower section of said conversion zone, iiowing said used contact material as a substantially compact column downwardly through za conned cooling zone while cooling it therein to a temperature at which it may be practically mechanically conveyed, maintaining a conned burning zone separate from said conversion zone, mechanically conveying the cooled contact material to a location suitable for its introduction to said burning zone, passing said contact material as a substantially compact column downwardly through said burningzone while contacting it with a combustion supporting gas to burn on.' said contaminant, removing heat from said contact material during said burning to control it below a heat damaging temperature, withdrawing regenerated contact material from said burning zone, maintaining a conilned heating zone at an-elevational level above said conversion zone, passing said regenerated contact material to said heating zone, passing the contact material downwardly through said heating zone as a substantially compact column, passing a suitable gaseous heat exchange medium cyclically through said columns in said cooling and heating zones in a direction countercurrent to the direction of contact material now in said zones so as to cool said contact material in said cooling zone to a practicable mechanical conveying temperature which is below about 1000 F. and to transfer the heat removed from said contact material passing through said cooling zone to said contact material passing through said heating zone, adjusting the temperature oi' said gas at a point in its cyclic path of travel outside of said cooling and heating zones in sufficient amount to maintain its temperature range substantially constant in said cooling and heating zones and passing the heated contact material from said heating zone to said conversion zone as the supply thereto. l

ll. A cyclic process of conducting endothermic conversions of duid reactants in the presence of a moving mass of contact material at temperatures above those at which the contact material may be practically mechanically conveyed which comprises introducing said iiuid reactant into contact with a substantially compact column of downwardly gravitatlng suitable contact material particles existing at a suitable temperature for the endothermic conversion of said iluid 'reactants, maintaining said reactants in contact with said contact material for a suilcient time to eiect said endothermic conversion and then withdrawing the fluid conversion products from said conversion zone, continuously replenishing said column at its upper end with reconditioned contact material existing at a suitable temperasaid conversion zone to a separate cooling zone and passing itdownwardly therethrough. as a substantially compact column, passing a suitable heat exchange gas'through said column in said cooling zone under conditions controlled to cool said contact material to a temperature at which it may bev practically mechanically conveyed, mechanically conveying said contact material to the level of a separate heating zone, passing said contact through said heating zone as a substantially compact column of gravitating particles, passing said heat exchange gas from said cooling zone through said column in said heating zone to transfer the heat removed from said cooling zone by said gas to said contact material moving through said heating zone and maintaining the temperature of the contact material entering said heating zone suiilcientiy below that of said contact material entering said cooling zone to insure saidl transfer of heat, returning the heat exchange gas after passage through said heating zone to said cooling zone, passing the cotact material from said heating zone through a separate reconditioning zone wherein it moves as a substantially compact column, passing a suitable reconditioning gas through said contact material uiumn in said reconditioning zone to further heat said contact material to a suitable temperature for supply to said conversion zone and passing the reconditioned contact material to said conversion zone as aforesaid.

l2. The methodfor conversion of a iiuid hydrocarbon charge containing a substantial amount oi' saturated hydrocarbons to gaseous ethylene containing products which comprises:

passing a suitable particle-form refractory tim!vv contact material serially downwardly through an uppermost heating zone, a reconditioning zone, a conversion zone and a cooling zone arranged in vertical series, said contact material moving through each of said zones as a substantially compact column of gravitating particles, and mechanically conveying the contact material from the cooling zone to the level of said heating zone for supply thereinto; contacting said contact material in said reconditioning zone with suitable gaseous material to heat it to a ltelnperature within the range about 1400 tal800 F. which is suitable for its supply to said conversion zone, passing said uid hydrocarbon charge into contact with the heated contact material in said conversion zone to effect the conversion of said charge to gaseous ethylene containing products, withdrawing said gaseous products from said conversionl zone substantially separately from said contact material, passing a suitable inert heat exchange gas through said column in said cooling zone at a rate controlled to cool by direct heat transfer the contact material to a temperature below about 1100 1l'. withdrawing the heat exchange gas from said cooling zone and passing it through said column in said heating zone to transfer the heat removed from said contact material in said cooling zone to the contact material in said heating zone and returning the gas after passage through said heating zone to said cooling zone.

13. A process for catalytic conversion of pctroleum hydrocarbon fractions to gaseous products containing substantial amounts of C4 hyv drocarbons and of aviation gasoline which comf is 1200" F. with a substantially compact column of downwardly moving adsorbent particle-form catalyst in a coniined conversion zone to eflect the conversion oi said hydrocarbons to gaseous products containing C4 hydrocarbons and aviation gasoline, withdrawing said gaseous products irom said conversion zone, withdrawing used catalyst from said conversion zone and passing i t as a substantially compact column through a confined cooling (zone, introducing a suitable heat exchange gas into said column in said cooling zone at a temperature substantially below that of said catalyst entering said cooling zone, passing said heat exchange gas through said column in said cooling zone countercurrently to the catalyst iiow to cool said catalyst to a. temperature below about 1000 F., mechanically conveying the cooled catalyst to a regeneration zone, passing said contact material through said regeneration zone as a substantially compact column while contacting it with an oxygen containing gas to burn of! therefrom carbonaceous contaminants, passing the regenerated catalyst vthrough a conilned heating zone as a substantially compact column, passing said heat exchange gas from said cooling zone through said catalyst in said heating zone countercurrently to the catalyst flow to transfer by direct heat transfer the heat removed by said gas from the catalyst passing through said cooling zone to the catalyst passing through said heating zone,

returning the heat exchange gas from said heating zone to said cooling zone and owing the heated catalyst from said heating zone to said conversion zone.

.at elevated temperatures in the presence of a suitable moving particle-form contact material .which comprises: passing said contact material cyclically in a closed path of travel which in- 4cludes a conversion zone wherein it moves down- 4wardly as a substantially compact column and is contacted at a suitable elevated conversion temperature with a iluid hydrocarbonlcharge to effect the conversion thereof with`r a resultant change in the heat level of the contact material due to the thermochemical reaction heat, through a reconditioning zone wherein it is treated to condition it for reuse in said conversion zone, and through at least one mechanical conveying zone wherein it is mechanically conveyed from a given level to a higher level; passing the cyclically moving contact material through a cooling zone as a substantially compact gravitating column at a point in its cyclic pathof travel after the conversion zone and before at least one conveying zone, passing a suitable inert heat exchange gas upwardly through said contact material column in said cooling zone under conditions controlled to cool said contact material to a temperature within the range about 100 F. to 1100 F., passing the contact material as a substantially compact gravitating column through a confined heating zone a pointv in its -cyclic path of travel after at least one conveying zone and before it passes to said conversion zone, said heating zone being a separate zone in said closed path of travel in addition to said conversion. reconditionining, cooling and mechanical conveying zones, passing said heat exchange gas from said cooling zone upwardly through the column in said heating zone while maintaining the temperature of the contact material entering said heating zone subystantialiy below that of the contact material entering said cooling zone whereby heat removed by the gas from said cooling zone is transferred to the column oi' contact material in said heating zone, returning the heat exchange gas after passage through said heating zone to said cooling zone to complete its cyclic path of travel, and substantially counteracting the lchange in heat level of the contact material in passing through said conversion zone by making an appropriate adjustment in the heat level of said heat exchange gas at at least one point in its cyclic path of travel outside of said heating and cooling zones.

15. In a process for conducting endothermic conversion of iluid hydrocarbon reactants at'controlled elevated temperatures in the presence of a moving particle-form contact material where-l in said contact material is passed through a cyclic path in which it moves as a substantially compact column through a conversion zone in which iii-supplies the reaction heat for effecting the endothermic conversion of a iluid hydrocarbon charge thereby undergoing a drop in temperature and through a reconditioning zone in which it nows as a substantially compact column while being subjected to reconditioning iiuixl to eil'ect at least its partial reconditioning for reuse in said conversion zone and in which cyclic path of travel the contact material is at least once mechanically conveyed from one level to a higher level in at least one mechanical conveying zone, the improvement which comprises, passing the hot contact material just prior to its passage to said mechanical conveying zone l through a separate cooling zone as a substantially compact column while cooling it therein to a temperature'beiow about i100 F. and passing the contact material after having been mechanically conveyed and prior to its passage through at least one o! said zones/,other than the conveying and cooling zones through a confined heating zone wherein it ilows as a substantially compact column, passing a suitable gaseous heat exchange medium cyclically through said columns in said cooling and heating zones in a direction countercurrent to the contact material now in each zone so as to cool said contact niaterial in said cooling zone to a practical'conveying temperature which is below about 1100 F. and to transfer at least a substantial part of the heat removed from said contact material in said cooling zone to the contact material inlsaid heating zone, adding sensible heat to the cyclically moving stream of contact material at at least one location in its path of travel to compensate for the heat absorbed by the reaction in said conversion zone and maintaining the temperature of the contact material entering said heating zone substantially below that ci' the contact material entering said cooling zone to insure the transfer of heat from said cooling zone to said heating zone by the heat exchange gas as aforesaid.

16. A cyclic process for conducting thermochemical conversions of fluid reactants in the presence of a moving mass of particle-forni contact material at temperatures above those at which such contact material may be practically mechanically conveyed which comprises, 'passing said contact material downwardly through two separate, superposed, contacting zones through which it flows as a substantially compact mass, passing a fluid reactant into contact with said contact material in one of said contacting zones to enect the thermochemlcal conversion thereof at a suitable range of elevated conversion temperatures and withdrawing fluid conversion products from said zone, passing a suitable conditioning gas through the mass of contact material in the other of said contacting zones to condition said contact material therein for return to the zone of iluld reactant conversion, `passing the contact material from the lower of said contacting zones downwardly through a cooling zone wherein it flows as a compact mass while being cooled 'to a temperature substantially below that in the contacting zone thereabove vand which is suitable for practicable mechanical conveying of said contact material, mechanically conveying said cooled contact material to a level above said contacting zones, passing the contact material after being conveyed and prior to its now again through at least one of said contacting zones through a heating zone in which it flows as a compact mass of particles while being heated, then passing the heated contact material from said heating zone to the contacting zone immediately therebelow, passing a suitable heat exchange gas cyclically through the mass of contact material in said heating and cooling zones to absorb heat from the contact material in said cooling zone and thereby effect said cooling thereof and to transfer at least a substantial part of the heat absorbed in said cooling zone to the contact material in said heating zone.

i7. In a cyclic process for the endothermic conversion of fluid hydrocarbon reactants in the presence of a suitable heated particle-form solid contact material at temperatures above those at which it is practical to mechanically convey said contact material wherein the contact material passes in series through two superposed contact ing zones in each of which it flows as a substantially compact column, one of said zones being a conversion zone and the other being a burning zone, and wherein a iluid hydrocarbon charge is passed into contact with the column of contact material in said conversion zone to effect the endothermic conversion of said reactants to lower boiling uid hydrocarbon products, at a suitable elevated conversion temperature which is substantially above that at which said contact material may be practically mechanically conveyed, said conversion resulting in the deposition of carbonaceous material on said contact material, and wherein an oxygen containing gas is passed through said column in said burning zone to burn carbonaceous material from the contact material and to eiect the increase in the sensible heat content of said contact material to a level at which it may supply the heat of endothermic reaction in said conversion zone without being cooled below a suitable elevated conversion temperature, the improvement which Vin which it ows downwardly as a substantially compact column, then passing the heated contact material from said'heating zone to the contacting zone immediately therebelow, passing a suitable inert heat exchange gas through said column in said cooling zone to cool said contact ma- 22 terial to a temperature at which it may be practically mechanically conveyed, which temperature is below about 1100 F., passing the heat exchange gas from said cooling zone through the column oi' contact material in said heating zone' to transfer the heat removed from the contact material in said cooling zone to the contact material moving through said heating zone, re-

turning the heat exchange gas after passageV through said heating zone to said cooling zone.

1B'. In a cyclic process for conversion o! fluid reactants at elevated temperatures wherein a particle-form solid material is passed continuously through a cyclic path of travel which includes two contacting zones and at least one mechanical conveying zone wherein it is mechanically conveyed from a low level to a higher level, one of said contacting zones being a conversion zone wherein the solid material is contacted with iluid reactants at elevated temperatures to eiiect conversion of said reactants to valuable conversion products and the other contacting zone being a reconditioning zone in which the solid material is at least partially conditioned for reuse in said conversion zone, the improvement which comprises, passing said solid material as a substantially compact gravitating column through a separate cooling zone at a location in its path of travel prior to its entrance into said mechanical conveying zone, passing a suitable inert heat exchange gas through said column in said cooling i zone to effect a suillcient removal of heat from said solid material to lower its temperature to a level at which it may be practically mechanically conveyed, and passing said solid material as a substantially compact gravitating column through a vheating zone at a location in its cyclic path of travel after it has been conveyed and above at least one of said contacting zones, said heating zone `being a separate zone in said closed path of travel in addition to said conversion, reconditioning, cooling and conveying zon, passing a suitable heat exchange gas upwardly through said columin in said cooling zone to eifect suiiicient removal of heat from the solid material to lower its temperature to a level at which it may be practically mechanically oonveyed, said level being substantially below that in the contacting zone immediately above said cooling zone, passing the heat exchange gas from said cooling zone upwardly through said column in said heating zone to transfer to the solid material therein the heat removed from the solid material in said cooling zone and returning the heat exchange gas to said cooling zone, and

i maintaining the temperature of the solid material entering said heating zone below that oi the solid material entering said cooling zone by an amount which will insure substantially complete transfer of said heat removed from said cooling zone to said heating zone by exchanging heat with the solid material to compensate for the reaction heat in said conversion zone at at mechanical conveying zone wherein it is me-l chanically conveyed from a low level to a higher level, one of said contacting zones being a conversion zone wherein the solid material is oontacted with fluid reactants at elevated tempera- 23 tures to eii'ect conversion oi.' said reactants to valuable conversion products and the other contacting zone being a reconditioning zone in which the solid material is at least partially conditioned for reuse in said conversion zone, the improvement which comprises, passing said solid material as a substantially compact gravitating column through a separate cooling zone at a location in its path of travel prior to its entrance into said mechanical conveying zone, passing a suitable inert heat exchange gas through said column in said cooling zone to effect a suicient removal of heat from said solid material to lower its temperature to a level at which it may be practically mechanically conveyed, and passing said solid material as a substantially compact gravitating column through a heating zone at a location in its cyclic path of travel after it has been conveyed and above at least one of said contacting zones, said heating zone being a separate zone in said closed path of travel in addition to said conversion, reconditioning, cooling and conveying zones, passing a suitable heat exchange gas upwardly through said column in said cooling zone to eiect sunicient removal of heat from the solid material to lower its temperature 24 to a level at which it may be practically mechanically conveyed, said level being substantially below that in the contacting zone immediately above said tooling zone, passing the heat exchange gas from said cooling zone upwardly through said column in said heating zone to transfer to the solid material therein substantially all of the heat removed from the solid material in said cooling zone and returning the heat exchange gas from said heating zone to said cooling zone, and maintaining the temperature of the contact material entering said heating zone sufilciently below that of the contact material entering said cooling zone to insure said heat transfer by said heat exchange gas from said cooling zone to said heating zone.

JOHN A. CROWLEY. Jn.

REFERENCES CITED The following references are of record in the ie of this patent;

UNITED STATES PATENTS Number Name f Date 2,239,801 Voorhees Apr. 29, 1941 2,399,450 Ramseyer Apr. 30, 1946

Claims

1. A METHOD FOR CONDUCTING THERMO-CHEMICAL CONVERSIONS OF FLUID REACTANTS AT CONTROLLED ELEVATED TEMPERATURES IN THE PRESSENCE OF A SUITABLE MOVING PARTICLE-FORM SOLID CONTACT MATERIAL WHICH COMPRISES: CONTACTING SAID FLUID REACTANTS AT A SUITABLE ELEVATED CONVERSION TEMPERATURE WITH A SUBSTANTIALLY COMPACT COLUMN OF DOWNWARDLY MOVING SOLID PARTICLE-FORM CONTACT MATERIAL IN A CONFINED REACTION ZONE TO EFFECT SAID CONVERSION OF SAID REACTANTS, WITHDRAWING FLUID CONVERSION PRODUCTS FROM SAID REACTION ZONE, WITHDRAWING USED CONTACT MATERIAL FROM SAID REACTION ZONE AND PASSING IT AS A SUBSTANTIALLY COMPACT COLUMN THROUGH A CONFINED COOLING ZONE, INTRODUCING A SUITABLE HEAT EXCHANGE GAS INTO SAID COLUMN IN SAID COOLING ZONE AT A TEMPERATURE SUBSTANTIALLY BELOW THAT OF SAID CONTACT MATERIAL ENTERING SAID COOLING ZONE AND PASSING SAID GAS THROUGH SAID COLUMN IN SAID COOLING ZONE TO COOL THE CONTACT MATERIAL SUBSTANTIALLY BELOW THE TEMPERATURE IN SAID REACTION ZONE, PASSING THE COOLED CONTACT MATERIAL FROM SAID COOLING ZONE THROUGH A SEPARATE RECONDITIONING ZONE WHEREIN IT IS TREATED TO RENDER IT SUITABLE FOR REUSE IN SAID REACTION ZONE, PASSING THE RECONDITIONED CONTACT MATERIAL TO A HEATING ZONE AND PASSING IT THROUGH SAID HEATING ZONE AS A SUBSTANTIALLY COMPACT COLUMN, WITHDRAWING SAID HEAT EXCHANGE GAS FROM SAID COOLING ZONE AND PASSING IT THROUGH SAID COLUMN IN SAID HEATING ZONE SO AS TO TRANSFER HEAT REMOVED FROM SAID CONTACT MATERIAL PASSING THROUGH SAID COOLING ZONE BACK TO SAID CONTACT MATERIAL PASSING THROUGH SAID HEATING ZONE, WITHDRAWING THE RESULTING COOLED HEAT EXCHANGE GAS FROM SAID HEATING ZONE AND RETURNING IT TO SAID COOLING ZONE.