US2763598A

US2763598A - Method of improving the yield of reformate in the process of reforming hydrocarbons

Info

Publication number: US2763598A
Application number: US285484A
Authority: US
Inventors: Kenneth M Elliott
Original assignee: Socony Mobil Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1952-05-01
Filing date: 1952-05-01
Publication date: 1956-09-18
Anticipated expiration: 1973-09-18

Description

fivaph 18, 1956 ELLIOTT 2,763,9

E METHOD OF IMPROVING THE YIELD OF REFORMATE IN THE PROCESS OF REFORMING HYDROCARBONS Filed May 1, 1952 3 Sheets-Sheet l t E M EE N m .1 F. M N w E m E 5 m w E M w M Y 1/ 4 4 E E E E PW E E E E a. W 7 E A! 5 mm 6 W i g. pa 6 W 4 4. WE W EV 1 Q 5 M W 6 Q0 1 MM 4A 1 W 6 9. WTU| .7 m MW MM 0 E 1 m EE A M m w m 5 5 W W E V a J 4 W 2 I 7 Mm" H 0 y w A E w 5 E JW E Sept 11, 1956 uo -r 2,763,598

METHOD OF IMPROVING THE YIELD OF REFORMATE IN THE PROCESS OF REFORMING HYDROCARBONS Flled May 1, 1952 3 Sheets-Sheet 2 5 & M m w W V 1 m A B 4 m a u L.

F D ME M hm 2 NE mfl 0P VP 0F 3U EU K. M. ELLIOTT METHOD OF IMPROVING THE YIELD OF REFORMATE IN THE PROCESS OF REFORMING HYDROCARBONS Filed May 1, 1952 5 Sheets-Sheet 3 I N VEIV TOR.

HGENT United States Patent METHOD OF IMPROVING THE YIELD OF REFOR- MATE IN THE PROCESS OF REFORMING HY- DROCARBONS Kenneth M. Elliott, Woodbury, N. 1., assignor to Socony Mobil Oil Company, Inc., a corporation of New York Application May 1, 1952, Serial No. 285,484

4 Claims. (Cl. 196-50) The present invention relates to the treatment of hydrocarbon mixtures containing hydrocarbons convertible to aromatic hydrocarbons to increase the concentration of aromatic hydrocarbons therein and, more particularly, to the treatment of primarily aliphatic mixtures of by drocarbons to increase the octane rating thereof.

It is well-known that the sum total of the dehydrogenating, hydrogenating and dehydrogenating-cyclizing reactions occurring when a mixture of hydrocarbons containing hydrocarbons convertible to aromatic hydrocarbons such as a virgin naphtha or a cracked naphtha is contacted with a reforming catalyst at elevated temperatures is an increase in the concentration of aromatic hydrocarbons in the product of the treatment. This end result is generally known as reforming, and the catalysts are generally known as reforming catalysts.

It has now been found that in a reforming operation employing a moving bed of particle form reforming catalyst, that the yield of reformate is serious reduced if (1) the catalyst in any zone except the upper 3 volume per cent of the catalyst bed is at a temperature lower than 5 F. below the temperature of the vapors surrounding the catalyst, and (2) any catalyst in the lower 70 per cent of the bed contains more than about 0.7 weight per cent of loosely-bound oxygen and/or water. It has now been discovered that the yield of reformate from a given charge stock can be kept at a maximum for catalyst inlet temperatures below 800 F. when the ratio of the vapor stream heat capacity to the catalyst stream heat capacity is adjusted to be greater than about 1.25 and preferably greater than about 1.50 and when a minimum residence time, depending on the temperature and generally less than 60 minutes, is provided in the top 20-30 volume per cent of the bed. For catalyst inlet temperatures above 800 F. there is no lower limit on the heat capacity ratio but some minimum contact time, depending on the temperature, must be provided in the top 20%-30% of the bed. Accordingly, it is an object of the present invention to provide a method of operating a moving bed catalytic reforming process wherein a maximum yield reformate of given aromatic content is obtained from a given charge stock. It is another object of the present invention to provide a method of operating a moving bed catalytic reforming process wherein the ratio of the vapor stream heat capacity to the catalyst stream heat capacity and the catalyst and vapor stream temperatures are adjusted so that the catalyst in the lower 97 volume per cent, preferably the lower 99 volume per cent, of the bed is at a temperature not lower than 5 F. below the temperature of the vapor immediately surrounding that catalyst. It is a further object of the present invention to provide a method of operating a moving bed catalytic reforming process so that the catalyst in the lower 70 volume per cent, preferably the lower 80 volume per cent of the catalyst bed contains less than 0.7 and preferably less than 0.5 weight per cent of looselybound oxygen and/or water. It is also within the purview of the present invention to provide a method of operating a reforming process wherein the minimum average temperature in the 30 volume per cent and preferably in the 20 volume per cent of the catalyst bed contiguous to the catalyst inlet is determined by the equation:

Minimum average temperature, Er-750+? where T is catalyst contact time in 20% of the catalyst bed expressed as minutes. These and other objects and advantages of the present invention will become apparent from the following description thereof taken in conjunction with the drawings, in which:

Figure 1 is a highly diagrammatic illustration of a reactor, a regenerator or kiln and auxiliary equipment in which the method of the present invention can be carried out;

Figure 2 is a highly diagrammatic illustration of two reactors in series relation which can be used in conjunction with the regenerator or kiln and auxiliary equipment illustrated in Figure 2 in accordance with the principles of the present invention, and

Figure 3 is a highly diagrammatic illustration of a reactor which can be used in conjunction with the regenerator or kiln and auxiliary equipment illustrated in Figure 1 in accordance with the principles of the present invention.

In general, it is preferred to operate in accordance with the principles of the present invention with a split flow of the liquid hydrocarbon feed introduced at a point intermediate the catalyst inlet and the catalyst outlet. However, totally counter-current flow of the feed with respect to the flow of the catalyst can also be employed. Accordingly, the conditions set forth hereinbelow have been found to provide satisfactory results.

Reactor Broad Preferred Vapor Inlet Temp, F 100-1, 100 000-1060 Catalyst Inlet Temp, "F 100-1, 200 700-1, 050 Space Velocity: Volume Naptha/Hour/Voh ume of Catalyst t. 0 1-6. 0 0 5-27 5 Recycle Ratio: Mols Hydrogen/Mole Naphthal-8 2-5 Mols Recycle Gas/Mols N aphtha 1-15 4-10 Vapor Stream Heat Capacity/ Catalyst Stream Heat Capacity l00-0v 05 1. 25 Pressure, p. s. i. a 15 600 100* 300 galtalyst Residence Time, minutes 20 50 Temperature, Fr 6004, 100 700-1, 100 Pressure, p. s. i. a 15-600 15-35 While any reforming catalyst in particle form can be used, presently it is preferred to use a chromia-alumina catalyst, particularly a chromia-alumina bead catalyst, comprising at least mol per cent alumina and 18 to 30 mol per cent chromia.

When a reforming catalyst is circulated cyclically through a reforming zone and a regenerating zone, it has been found that oxygen in some form, probably as a higher oxide of chromium although the present invention is not predicated upon the exact form in which the oxygen is present in the catalyst, is present on the regenerated catalyst and is reduced in the reforming zone to yield water. The water so produced has been found to have a detrimental effect upon the yield of reformate. The loosely-bound water and oxygen content of a catalyst may be determined by contacting the catalyst with hydrogen at 1100" F. for 30 minutes.

Thus, for example, a virgin Columbian naphtha was reformed to illustrate the benefits derived from operating in accordance with the principles of the present invention. In Case I the catalyst is pretreated to remove loosely found oxygen and/or water before it is passed to the reactor. Case II is illustrative of the same overall operation except for the pretreatment of the catalyst prior to entry into the reactor. It will be noted that the gasoline yield in Case II is 3 per cent lower than in Case I. Cases III and IV are two illustrative examples of operations carried out in accordance with theprinciples of the present invention wherein the catalyst is not pretreated but the high yields normally associated with catalyst pretreatment to remove loosely-bound oxygen and/or water are obtained. In Case III the catalyst rate of flow and the vapor rate of flow have been correlated to provide a contact time of approximately 20 minutes in the top 20 per cent of the bed as compared with a contact time of about 5 minutes in Case II by reducing the catalyst flow rate. In order to obtain gasoline of the same octane rating as was produced under the conditions represented by Cases I and II, it was necessary to reduce the vapor inlet temperature from 1025 F. to 985 F. In Case IV the vapor inlet temperature was the same as in Cases I and II (1025 F.) and the liquid space velocity was increased to produce a gasoline having the same octane rating as that of Cases I and II.

Table 1 Charge Stock:

Virgin Columbian Naphtha, BR. 200-400 F. Octane N umber- F-l (clear) F-l 3 cc. TEL/ga Catalyst: Fresh chromia-alumina beads comprising at least 70 mol percent alumina, balance chromia.

Case Number Case I Case II Crisis Case IV Catalyst Pretreatment Yes No No N Water and Loosely-Bound Oxygen Content of Catalyst Feed, Wt.

Percent 0. 5 1.5 1. 5 1. 5 Pressure, p. s. i. a 190 190 190 190 Gas Recycle M01 Ratio- 6 6 6 Catalyst Inlet Temp., F 800 800 800 800 Space Velocity, V./Hr./V 1 0 1.0 1.0 4 5 Vapor Contact Time, ec. 7. 2 7. 2 7.2 1.6 Catalyst Contact Time, Min- 27 27 105 80 Catalyst to Naphtha Ratio 2. 92 '2. 92 0.73 0. 24 Vapor Stream Heat Capacity/Catalyst Stream Heat Capacity 2.0 2.0 8.0 25. Vapor Inlet Temp., F 1,025 1, 025 985 1, 025 Vapor Outlet Temp., F. 8 856 902 963 Average Temp. Catalyst Bed, F 930 935 930 980 Average Temp. Top 20 percent Cataly Bed, "F 906 912 917 970 Catalyst Time Top 20 percent Catalyst Bed, Minutes 5. 3 5.3 21. 16. Octane No. 10 R. V. P Gasoline- Clear 81 81 81 81 F1 3 cc. TEL/gaL 92 02 92 92 Yield, 10 R. V. P. Gasoline, Vol.

percent of charge 94 91 94 94 When evaluating the improvement in gasoline yield obtained by operating in accordance with the principles of the present invention as illustrated by Cases III and IV, it must be borne in mind that a 3 per cent increase in yield of 10 R. V. P. gasoline having an octane number of 92 (F-1+3 cc. TEL/gal.) for a 10,000 B. P. S. D. plant is about $500,000 per year.

The data presented in Table I establish that, when catalyst is not pretreated and enters the reactor containing in excess of 0.7 weight per cent loosely-bound oxygen and/ or water, substantially the same yield of gasoline of given octane number as obtained with pretreated catalyst can be obtained by operating with special conditions in the upper 30 volume per cent, preferably the upper volume per cent of the catalyst bed.

The removal of loosely-bound oxygen and/or water from the catalyst in the upper 20 to of the catalyst bed under conditions such that maximum gasoline yield is attained has been found to be a function of both time and temperature. The limiting relationship between time Catalyst Residence Time required in 20 Vol. percent of Catalyst Bed eontiguous to Catalyst Inlet (minutes) Average Temp., F., 20 Vol. percent of Catalyst Bed contiguous to Catalyst Inlet at least 70. at least 23. at least 14.

Accordingly, the minimum average temperature in the 20 volume per cent of the catalyst bed contiguous to the catalyst inlet is expressed in terms of the catalyst residence time in 20 volume per cent of the bed by the equation,

where T is the catalyst residence time in minutes.

Furthermore, it has been found that when the catalyst inlet temperature is 800 F. or less, the ratio of the vapor stream heat capacity to the catalyst stream heat capacity must be at least 1.25 and preferably at least 1.50 to obtain the conditions necessary to produce the temperature and the oxygen and/ or water conditions set forth hereinbefore. On the other hand, when the catalyst inlet temperature is above 800 F., the ratio of the vapor stream heat capacity to the catalyst stream heat capacity can be reduced below 1.25 to a value only limited by the equipment and economic considerations.

Therefore, the present invention provides a method for reforming hydrocarbons in the presence of a reforming catalyst initially containing more than 0.5 weight per cent loosely-bound oxygen and/or water as defined hereinbefore wherein not more than about 3 volume per cent, preferably not more than about 1 volume per cent of the catalyst bed contiguous to the catalyst inlet is less than about 5 F. below the temperature of the vapor immediately surrounding it and the catalyst in the lower 70 volume per cent and preferably the lower volume per cent of the bed contains less than about 0.7 and preferably less than about 0.5 weight per cent of looselybound oxygen and/ or water as defined hereinbefore and wherein the minimum average temperature in the 20 volume per cent of the bed contiguous to the catalyst inlet is expressed by the equation:

Minimum average temperature, 01122750 (3290) and wherein the ratio of the vapor stream heat capacity to the catalyst stream heat capacity is at least 1.25, preferably 1.50 for catalyst inlet temperatures of 800 F. or less and in general is about 1.25 to 100.

Vapor stream heat capacity is defined as the product of the pounds of liquid reactant per hour and the specific heat of the liquid reactant entering the reactor and catalyst stream heat capacity is defined as the product of the pounds of catalyst per hour and the specific heat of the catalyst entering the reactor or reformer.

The method of reforming substantially non-aromatic mixtures of hydrocarbons, for example, primarily aliphatic mixtures of hydrocarbons such as virgin naphthas, cracked naphthas and mixtures of virgin or straight run naphtha and cracked naphtha in accordance with the principles of the present invention, can well be discussed in conjunction with the drawings. Those skilled in the art will recognize that for simplicity certain auxiliary equipment such as compressors, flares, depropanizing and distillation equipment together with other equipment for after treating the reformate have been omitted since the inclusion thereof is not essential to an understanding of the present invention. Furthermore, those skilled in the art avenues will immediately recognize that the reformers depicted in Figures 2 and 3 can be used in conjunction with a kilnor regenerator such as illustrated in Figure 1 or any other suitable kiln or regenerator in which particle form catalyst contaminated by a carbonaceous deposit can be reactivated by combustion of the carbonaceous deposit in a combustion supporting gas such as air.

Referring now to Figure 1. Active catalyst is accumulated in reactor catalyst feed bin 11 and flows into surge tank 12 through conduit 13. Since thereactor 14 preferably is operated at superatmospheric pressures reactor 14 is provided with a suitable reactor sealing means whereby catalyst in surge tank 12 at a pressure lower than that of the reactor 14 can be introduced into reactor 14. Of course, when reactor 14 is operating at substantially atmospheric pressure, the sealing means is not required.

The sealing means illustrated comprises two gas-

tight valves

15 and 16 between which is located a pressuring chamber or pot 17. This sealing means is operated cyclically as follows: With gas-

tight valves

15 and 16 closed, a non-flammable or inert gas is introduced into pot 17 to purge the chamber. Thus, a non-flammable gas such as flue gas drawn from a source not shown is passed through

lines

18 and 20 with valve 19 open and valve 24 closed into pot 17 and vented therefrom to a flare through lines 21 and 22 with valve 25 closed and valve 23 open. After purging, pot 17 is filled to a predetermined level with catalyst from surge tank 12 by opening gas-tight valve 15. With pot 17 filled with catalyst to the predetermined level, gas-tight valve 15 is closed, valve 23 is closed and with gas-tight valve 16 and

valves

19 and 25 closed, pressuring gas such as recycle gas is drawn from holder 26 through

lines

27 and 20 under control of valve 24 and introduced into pressuring pot 17 until the pressure therein is at least equal to but preferably somewhat greater, say about 5 p. s. i. greater, than the pressure in reactor 14. Gas-tight valve 16 then is opened and the catalyst flows into reactor or reformer 14. The residual pressuring gas in pressuring pot 17 is then vented to a flare, not shown, through lines 21 and 28 with valve 25 open and valve 23 closed completing the cycle. From this point the course of the catalyst through the reactor as a substantially compact column, thence to the regenerator and back to feed bin 11, will be followed. Thereafter the path of the reactant and product will be followed through the reactor to the point of entry into the aftertreating equipment.

The catalyst containing more than 0.5 weight per cent loosely-bound oxygen and/ or water as defined hereinbefore, enters the reactor 14 at a temperature of about 100 to about 800 F, and in some operations at temperatures in excess of 800 F. However, for the purpose of description, the catalyst temperature inlet temperature is not in excess of about 800 F. The pressure in the reactor can be about 15 to about 600 p. s. i. a. and preferably about 100 to about 300 p. s. i. a. with reactor temperature of the order of 800 to 1080 F. The catalyst flows downwardly as a substantially compact column through reactor 14 to pass through any suitable catalyst flow control device 29 into surge bin 30.

It is in area A of Figure 1 that the temperature of the catalyst can be permitted to be more than 5 F. below the temperature of the vapor immediately surrounding the catalyst and in Area B that the loosely-bound oxygen and/ or water content of the catalyst is reduced to 0.7 and preferably to less than 0.5 weight per cent of the catalyst by the stripping action of the naptha and the recycle gas.

The catalyst is withdrawn from surge bin 30, which is at reactor pressure, through any suitable reactor sealing device and means for transferring particle form solid from an area of superatmospheric pressure to an area of lower pressure. Such a reactor sealing means or transfer device is necessary only when the regenerator is operated at a pressure below that of the reactor. In Figure 1 the reactor sealing means is a depressuring lock similar to the pressuring lock through which the catalyst is introduced into the reactor and operated in a similar cyclic manner.

Thus, with gas-tight valves 31 and 32 closed, depressuring pot 33 is purged with an inert or non-flammable gas such as flue gas. The non-flammable or inert gas is drawn from a source not shown through lines 34- and 35 with valve 36 open and valve 37 closed and vented to a flare through

lines

38 and 39 with valve 40 open and valve 41 closed.

Valves

36 and 40 are closed and a suitable gas such as recycle gas is drawn from a holder such as 26 through

lines

27, 42 and 35 under control of valve 37. When the pressure in pot 33 has been raised to that of surge pct 30 and reactor 1%, valve 37 is closed, gastight valve 31 is opened and catalyst flows from surge tank 30 into depressuring pot 33 to fill the pot 33 to a pre determined level. Gas-tight valve 31 is then closed and valve 41 opened and the pressure in depressuring pot 33 reduced to that of the kiln or regenerator by venting the gas contained therein to a flare through pipes 38 and 43. Gas-tight valve 32 then is opened and the catalyst flows into surge tank 98, through valve 99 into chute 4-4. Gastight valve 32 is closed; completing the cycle.

Chute 44 carries the spent catalyst to any suitable catalyst transfer device such as a gas-lift, an elevator or the like for transporting the spent catalyst to the regenerator or kiln. The catalyst transfer device illustrated is a bucket elevator 45 such as more fully described in U. S. Patent No. 2,531,192. The catalyst flows through chute 44 to boot 46 of elevator 45 Where it is picked up by the elevator buckets and raised to elevator head 4'7. It is to be noted that the elevator illustrated in a highly diagrammatic manner in Figure 1 is provided with buckets having pockets or compartments one or more for spent catalyst and the others for regenerated 0r reactivated catalyst. The catalyst is raised in the buckets of elevator 45 to the head 47 thereof where the buckets discharge into elevator spout 48. Elevator spout 48 is provided with a divided discharge d9 constructed and arranged so that regenerated catalyst flows into chute 50 which in turn is constructed and arranged so that the catalyst fines flow through chute 52 to the gas elutriator 53 while the balance of the regenerated catalyst flows through chute 51 to reactor catalyst feed bin 11 and the spent catalyst flows along chute 54 to kiln or regenerator feed hopper 55.

The spent catalyst flows through conduit 56 into kiln or regenerator 5'7. (iln or regenerator 57 is of any suitable design for burn-ing the carbonaceous deposit on the spent catalyst. Presently, it is preferred to use a multi-stage kiln having a plurality of alternate burning and cooling stages operating at a temperature of about 600 to about 1400 F. and preferably at about 700 to about 1100 F. at a pressure of about 15 to about 600 p. s. i. a. and preferably presently at a pressure of about 15 to about 35 p. s. i. a. A multi-stage kiln is more fully described in U. S. iatent No. 2,469,332. Briefly, such a multi-stage kiln or regenerator comprises an uppermost surge section and about 6 to about 20 burning zones alternating with cooling zones. The number of burning stages or zones being dependent upon the amount of earbonaceous contaminant to be burned off the catalyst. The cooling zones or stages are provided with heat transfer tubes through which a heat transfer medium such as high pressure steam, water, low melting alloys, or fused inorganic salts can be passed. Details of the kiln are not shown in Figure l.

The spent catalyst flows from feed bin 55 through the kiln 57 and passes through conduit Stli to chute 59 by means of which the reactivated catalyst is transferred to any suitable catalyst transfer device by means of which the active catalyst is transported to reactor catalyst feed bin 11. Suitable catalyst transfer devices are gas-lift, elevator, etc. In Figure 1, a bucket elevator such as described more fully in U. S. Patent No. 2,531,192 is in- 7 dicated. The reactivated catalyst passes along chute 59 to boot 46 of elevator 45, is raised by the buckets therein to elevator head 47, discharged into elevator spout 48, flows through divided spout discharge 49 and along

chutes

50 and 51 to reactor catalyst feed bin 11.

The fines among the particles of reactivated catalyst flow through chute 52 to gas elutr-iator 53. In gas elutriator 53 the larger particles of catalyst drop out of the gas stream and are discharged into conduit 60 through which the particles flow to chute 59 and the catalyst transfer device 45. The smaller particles are carried with the gas stream through conduit 61 to cyclone separator 62 where the catalyst particles are discharged through line 63, and the gas escapes through vent 64.

Considering the flow of vapors through the reactor 14, return to Figure l. A mixture of non-aromatic hydrocarbons such as a virgin naphtha is drawn from a source not shown through line 94, drier 90, and line 65 into furnace 66. In furnace 66 the naphtha or charge stock is heated to about 850 F. to about 1080 F. and flows through line 67 under control of valve 68 to reactor 14.

As is Well known, the reforming reaction can 'be carried out in the presence or absence of hydrogen. When the reforming reaction is to be carried out in the presence of hydrogen, the recycle gas is a hydrogen-containing gas containing about 25 per cent to about 80 per cent, preferably about 35 per cent to about 60 per cent hydrogen and the balance C1 to Cs hydrocarbons. Under other conditions the hydrogen content of the recycle gas can be below 25 per cent. The recycle gas is drawn from a source such as holder 26 through pipe 69 to furnace 70 in which the recycle gas is heated to about 850 to about 1300 P. such that the mixture of recycle gas and charge stock in line 67 enters the reactor 14 preferably at about 900 to about 1060 F. The recycle gas then passes through pipe 71 under control of valve 72 to be admixed With the charge stock in the ratio of about 1 to 15 preferably about 4 to mols of gas per mol of charge stock to form a charge mixture. When the reforming reaction is carried out in the presence of hydrogen, the hydrogencontaining recycle gas is mixed with the charge stock in the proportion of about 1 to about 8 mols, preferably about 25 mols of hydrogen per mol of naphtha. The average molecular weight of the charge stock is determined in the usual manner from the A. S. T. M. distillation curve.

As shown in Figure 1, the charge mixture enters the reactor at the midpoint thereof and is distributed across ,1

the cross-section of the reactor by a distributor, not shown. Distribution of the charge mixture to the catalyst above and below the charge mixture inlet is controlled by throttling devices of any suitable type such as

throttle valves

73 and 74 in

reformate withdrawal lines

75 and 76 respectively.

Throttling devices

73 and 74 are of any suitable type whereby the volume of vapor passing therethrough can be regulated. By means of such throttling devices, the quantity of charge mixture passing through the upper reforming zone, i. e., reactor volume above the charge mixture inlet, and the volume of charge mixture passing through the lower reforming zone, i. e., reactor volume below the charge mixture inlet can be regulated and controlled to provide the required ratio or vapor stream heat capacity to catalyst stream heat capacity, the temperature of the catalyst in the upper 3 per cent and preferably 1 volume per cent of the upper reforming zone, and the concentration of loosely-bound oxygen and/or water below 0.7 and preferably below 0.5 weight per cent in the lower 70 volume per cent and preferably the lower 80 volume per cent of the upper reforming zone.

The charge mixture passes from inlet 67 upwardly counter-current to the downwardly flowing substantially compact column of catalyst in the upper reforming zone.

About 20% to about of the charge mixture can be passed through the upper reforming zone and the balance downwardly concurrent with the downwardly flowing substantially compact column of catalyst in the lower reforming zone. In the top 30%, preferably the top 20%, of the upper zone the loosely-bound oxygen and water content of the downwardly flowing catalyst is reduced to less than 0.7 and preferably less than 0.5 weight per cent.

The reformate produced in the upper reforming zone leaves the reactor through line 75 under control of throttling device 73. The reformate produced in the lower reforming zone leaves reactor 14 under control of throttling device 74 and passes through

lines

76 and 78 to line 75 where it is mixed with the reformate from the top zone. The combined stream passes through cooler 77 and line 79 to gas-liquid separator 81. In gas-liquid separator 31 the condensed hydrocarbons are withdrawn to after-treating, distillation, storage and distribution through line 83. Part of the water removed from the catalyst in the upper 30% of the top zone of reactor 14 may be removed as liquid through pipe 84 under control of valve 82. The non-condensed gases escape from gasliquid separator 81 through pipes 85 and 91 under control of valve 93 to gas recycle pipe 95. A portion of the gas equivalent to the net production in reactor 14 is withdrawn from pipe 85 to a recovery plant not shown through pipe 87 under control of valve 89.

In pipe 95 the recycle gases are transported to drier 96 where the water vapor removed from the catalyst in the top part of reactor 14 which was not condensed in separator 81 is removed from the recycle gas. The recycle gases then travel through pipe 97 to holder 26 ready for further circulation through the furnace and I'GQCEOI'.

Referring now to Figure 2. Non-aromatic mixtures of hydrocarbons such as naphthas can be reformed in two in-series reactors or reformers as illustrated in a highly diagrammatic manner in Figure 2. Thus, the active catalyst containing more than about 0.5 weight per cent loosely-bound oxygen and/ or water as defined hereinbefore, flows from a surge tank such as surge tank 12 of Figure 1 through a reactor sealing means such as the pressuring lock illustrated in Figure 2. The pressuring lock illustrated in Figure 2 comprises gas-tight valves and 116 and pressuring pot 117, and is operated in a cyclic manner. Gas-

tight valves

115 and 116 are closed and the pressuring pot 117 purged by passing a nonflammable or inert gas through pipes 113 and 120 under control of valve 119 with valve 124 closed into pressure pot 117. The purge gas is vented to a flare not shown through pipes 121 and 122 under control of valve 123; with valve 125 closed; gas-tight valve 115 then is opened and catalyst flows into pressuring pot 117 to a predetermined level. Gas-tight valve 115 is closed and with

valves

123, 125 and 119 closed, a suitable pressuring gas such as recycle gas is drawn from the holder 126 through

pipes

127 and 120 under control of valve 124 and introduced into pressuring pot 117 until the pressure therein is at least as high as that of

reactors

114 and 114a. Valve 124 is closed, gas-tight valve116 opened and catalyst flows as a substantially compact column into reactor 114. Gas-tight valve 116 is closed, valve 125 opened and the residual gas vented from pot 117 through

pipes

121 and 128 to a flare until the pressure in pot 117 is that of the surge tank.

The catalyst enters the reactor 114 at a temperature of about 100 to about 800 F., and in some operations at temperatures in excess of 800 F. However, for the purpose of description, the catalyst inlet temperature is not in excess of about 800 F. The pressure in the

re actors

114 and 114a can be about 15 to about 600 p. s. i. a. and preferably about 100 to about 300 p. s. i. a. with reactor temperatures of the order of about 800 to 1080 F. The catalyst flows downwardly through reactor 114 as a substantially compact column, passes through conduit 196 into reactor 114a through which the catalyst also flows as a substantially compact column to leave reactor 114a at a temperature of about 800 to about 1000 F. through catalyst flow control device 129. The spent catalyst passes through catalyst flow control device 129 into surge tank 130 and thence to any suitable device for transferring particles from an area of higher pressure to an area of lower pressure. The device illustrated is a depressuring device comprising gas-

tight valves

131 and 132 and depressuring pot 133. The reactor sealing means operates in a cyclic manner similar to the pressuring lock as follows: Pressuring pot 133 is purged with a nonlammable or inert gas such as flue gas, drawn from a source, not shown, through pipes 134 and 135 under control of valve 136 with gas-

tight valves

131 and 132 and valve 137 closed. The purge is vented to a flare not shown through

pipes

138 and 139 under control of valve 140 with valve 141 closed. Then

valves

136, 140 and 141 are closed and valve 137 opened and a suitable pressuring gas such as recycle gas drawn from a holder 126 through

pipes

127, 142 and 135 under control of valve 137 and introduced into depressuring pot 133 until the pressure is about that of surge tank 130. Gas-tight valve 131 is opened and catalyst flows from surge tank 130 into depressuring pot 133 until the latter is filled to a predetermined level. Gas-tight valve 131 is closed and valve 141 opened and the gas in depressuring pot 133 vented through

pipes

133 and 143 to a flare not shown until the pressure in depressuring pot is substantially that of the kiln or regenerator in which the spent catalyst is to be reactivated. Gas-tight valve 132 is opened and the catalyst flows into surge tank 199 and thence to chute 144 through which it flows to a suitable catalyst transfer device by means of which the catalyst is transferred to the regenerator. Gas-tight valve 132 is closed; completing the cycle. The catalyst is then reactivated in any suitable manner, for example, as described in conjunction with Figure 1.

It is in area A of Figure 2 that the temperature of the catalyst is not permitted to be less than F. below the temperature of the vapor immediately. surrounding the.

catalyst and in area B of reactor 114 that the looselybound oxygen and/ or water is reduced to less than 0.7 and preferably less than 0.5 weight per cent of the catalyst.

The charge stock is drawn from. a source not shown through line 165, heated infurnace 166 to about 850 F. to about 1080 F. and flows through line 167 to

reactors

114 and 114a under control of

valves

168 and 168a. Recycle gas of any suitable, composition, for example, when carrying out the reforming operation in the presence of hydrogen, a recycle gas containing about 25 per cent to about 80 per cent and preferably about 35 per cent to about: 60 per cent hydrogen, balance C1 to C6 hydrocarbons, is drawn from holder. 126 through

lines

127 and 169 and heated in furnace 170 to a temperature of about 850 to about 1300 P. such that the mixture of recycle gas and charge stock inline 167 enters

thereactors

114 and 114a preferably at about 900 to about 1060" F. The recycle gas passes from furnace 170 through pipe 171 under control of valve 172 to line 167 wherein it is mixed with the charge stock to form the charge mixture.

The recycle gas is mixed with the charge stock to produce a ratio of about 1 to about 8, preferably about 3 mols, of hydrogen per mol of naphtha.

The charge mixture of hydrocarbons to be reformed and recycle gas enters rea'ctor 114 through line 197 r and is distributed across the cross section of the reactor by means of a suitable distributor not shown. The charge mixture vapors flow upwardly countercurrent to the downwardly flow substantially compact column of catalyst. In the top 30% of reactor 114 the loosely-bound oxygen and water content of the downwardly flowing catalyst is reduced to less than 0.7 weight per cent and preferably less than 0.5 weight percent. The loosely-bound oxygen 10 is generally converted to water in this section of the reactor. The reformate leaves reactor 114 through line 175, passes through cooler 177 and line 179 into gasliquid separator 181 under the control of throttling device 173.

Throttling devices

173 and 174 are any suitable device such as a throttle valve whereby the volume of vapors issuing from reactor 114 can be regulated and maintained substantially constant. By means of throttling device 173, the volume of charge mixture passing through reactor 114 is regulated to provide, in conjunction with the temperature of the incoming catalyst and the temperature of the incoming charge mixture vapors, a control on the reforming conditions existing in reactor 114 and the amount of loosely-bound oxygen and/or water present on the catalyst in the reactor below area B and the temperature of the catalyst relative: to the immediately surrounding vapor in the reactor below area A.

The charge stock to be reformed in reactor 114a enters reactor 114a admixed with recycle gas as a charge mixture through line 198 and is distributed across the crosssection of the reactor by a suitable distributor, not shown. The vapors of the charge mixture flow downwardly concurrently with the downwardly flowing substantially compact column of catalyst. As in reactor 114 throttling device 174 controls the passage of charge mixture vapors through the reactor. Reformate leaves reactor 114a through line 176, passes through cooler 178, and line 180 under control of throttling device 174 to liquid-gas separator 182.

In liquid-gas separator 151 the condensed hydrocarbons are withdrawn to after-treating, distillation, storage and distribution through line 183. That portion of the water in the vapors from reactor 114 which was condensed in cooler 177 is removed through line 154 under control of valve 153. The gases escape from separator 181 through pipe 185 to pass under control of valve 193 through pipe 191 to recycle gas pipe 195. When desired or necessary, a part or all of the gas from separator 131 can be vented to a recovery system, not shown, through pipe 187 under control of valve 189. In pipe the gas is transported to drier 155 where the remainder of the water is removed from the recycle gas before it passes into line 156.

In liquid-gas separator 18?. the condensed hydrocarbons are Withdrawn to after-treating, distillation, storage and distribution through line 184. The gases escape from separator 182 through

pipes

136 and 192 under control of valve 194 to recycle gas pipe 156. When desired or necessary, all or part of the gas escaping from separator can be vented to a recovery system not. shown through pipe 183 under control of valve 190.

In Figure 3 is shown a very flexible system for use in reforming mixtures of hydrocarbons containing hydrocarbons convertible to aromatic hydrocarbons such as petroleum naphthas. Reactor 214 is provided with a plurality of pairs of inlets whereby the catalyst bed can be divided into two beds of a plurality of relative volumes. Reactor 21 i is also provided with effluent regulators whereby the volume of effluents from the two reforming zones and consequently the distribution of reactant to the respective zones can be eifectively controlled. The combination of these two instrumentalities provides a very large number of combinations by which a great variety of reforming conditions can be established and maintained.

Reactor 214 like reactor 14 is provided with a reactor catalyst feed bin such as 11 of Figure 1 from which the catalyst flows through a reactor sealing and charging means such as the pressuring lock formed between gastight valves 215 and 216. The pressuring lock operates in a cyclic manner as follows: With gas-tight valves 215 and 216 closed pressuring chamber 217 is purged with a non-flammable and/ or inert gas such as flue gas. The purge gas is drawn from a source not shown, passed through

pipes

218 and 220 under control of valve 219 with valve 224 closed. The purge is vented from pressuring chamber 217 to a flare not shown through

pipes

221 and 222 under the control of valve 223 with valve 225 closed. Valve 215 is then opened and catalyst flows into pressuring chamber 127 to a predetermined level. Gas-tight valve 215 then is closed,

valves

219, 223 and 225 are closed and valve 224 opened. A suitable pressuring gas such as a recycle gas is drawn from a source such as holder 226 through pipe 227 and introduced through pipe 220 until the pressure in pressuring pot 217 is at least that of the reactor 214. Valve 224 then is closed and gas-tight valve 216 opened. The catalyst flows from pressuring chamber 217 as a substantially compact column into reactor 214. When chamber 217 is substantially empty of catalyst, gas-tight valve 216 is closed and residual gas in pressuring chamber 217 is vented to a flare through pipe 221 under control of valve 225 until the pressure in chamber 217 has been reduced to atmospheric pressure. This completes the cycle.

The catalyst enters the reactor at a temperature of about 100 to about 1200 F., preferably about 700 to about 1050 F. and flows as a substantially compact column downwardly through reactor 214. During flow through the reactor, the catalyst becomes contaminated with a carbonaceous deposit which reduces its activity, i. e., the catalyst is spent. The spent catalyst leaves reactor 214 through catalyst flow control device such as a throttle valve 229 and flows into surge chamber 230. Catalyst is removed from surge chamber 230 by any suitable device for removing solid particles from a vessel at one pressure to a vessel at a lower pressure. Such a device can be the depressuring lock formed between gas-

tight valves

231 and 232.

The depressuring lock formed between gas-

tight valves

231 and 232 operates on a cycle similar to the pressuring lock described hereinbefore as follows: With gas-

tight valves

231 and 232 closed, depressuring chamber 233 is purged with a non-flammable and/or inert gas such as flue gas. Flue gas drawn from a source not shown is passed into chamber 233 through pipes 234 and 235 under the control of valve 236 with valve 237 closed. The purge is vented to a flare through

pipes

238 and 239 under the control of valve 240 with valve 241 closed. Valves 236 and 240 are then closed and a pressuring gas such as recycle gas drawn from a source such as holder 226 through pipe 242 under the control of valve 237 is passed through pipe 235 into chamber 233 until the pressure therein is equal to that in surge chamber 230 and reactor 214. Gas-tight valve 231 is then opened. Catalyst flows from surge chamber 230 into depressuring chamber 233 until the chamber 233 is filled to a pre-determined level. Gas-tight valve 231 is closed, valve 241 opened and the pressure in depressuring chamber 233 reduced to that of the kiln by venting the gas therein to a flare not shown through

pipes

238 and 243. Gas-tight valve 232 is then opened and the catalyst flows into surge tank 400 and thence into chute 244. The catalyst flows along chute 244 to any suitable catalyst transfer device such as a gaslift, elevator or kiln by means of which the catalyst is transferred to the kiln or regenerator.

Those skilled in the art will understand that when the kiln or regenerator is operated at the same or substantially the same pressure as the reactor, there is no need for a reactor sealing means such as the depressuring lock described hereinbefore.

Now the course of the reactant and recycle gas through the reactor 214 will be traced. The process illustrated in Figure 3 provides for the treatment of two different or similar charge stocks and will be described on the basis of two different charge stocks.

Thus, two feed stocks can be treated simultaneously in reactor 214. For example, feed stock (1) can be a West Texas virgin naphtha having a boiling range of 200 to 400 F. and feed stock (2) can be a blend of (a) 55 volume per cent California virgin naphtha and 45 volume per cent cracked naphtha from coking a Cali- 12 forniaresiduum. The naphthas can be treated simul taneously under diiferent conditions of reforming severity as set forth in Table II.

Table II Feed Stocks:

(1) Venezuelan virgin naphtha-BR 200400 F.

ctane Number- 39 61 (2) Blend of (a) 55 volume percent Ca v and (b) 45 volume percent cracked naphtha from coking a California residuum. Octane Number- F-l (clear) 65 Ii -1+3 cc. TEL/gal 76 Catalyst:

Chromia-alumina beads comprising at least 70 mol percent alumina, balance chromia. Water and loosely-bound oxygen content of regenerated catalyst 1.5 Weight percent. Average operating conditions in reactor:

Pressure, p. s. i. a- 190 Catalyst inlet temp., "F 600 S ace velocity 0.7 apor stream heat capacity/catalyst stream heat capacity 16. 0

Reactor Section Top Bottom Catalyst Volume percent of total 50 50- Charge Stock number 1 2 Volume percent of total charge to reactor 5O 50 Space Velocity O. 7 0. 7 Vapor Inlet Temp, F 1, 050 1, 000 Vapor Outlet Temp., F 923 Average Temp, "F 983 952 Catalyst Time Top 20% of upper bed, minutes-.. 30 Ctgl'ialyst Average Temp. Top 20% of upper bed, 970

t Maximum Temperature ifierence Between catall yst and vapor in bottom 97% of upper bed, 4 Maximum Water and Loosely-Bound Oxygen Content of Catalyst in lower 80% of top zone 0. 5 Recycle Gas: Mols gas/Mole Naphtha 6 (5 Mols Hydrogen/Mole Naphtha 2. 4 2. 4 Gasoline Octane Number:

F-l (clear) 91 F-l-l-3 cc. TEL/gal 9s 92 Charge stock (1) is drawn from a source not shown through line 265 and heated to a temperature of about 900 F. in furnace 266. The heated charge stock is discharged from furnace 266 into line 267. In line 267 the charge stock (1) is mixed with recycle gas drawn from holder 226 through pipe 294, heated in furnace 295 to about 1200" F. such that when passed through pipe 296 under control of valve 298 into line 267 and mixed with heated charge stock (1) to form charge mixture (1), the temperature of charge mixture (1) is about 1050 F. The charge mixture (1) then passes through manifold 268. From manifold 268 the charge mixture (1) passes to inlet 271 under control of valve 276 and its attached distributor (not shown) under control of valve 276 so that the catalyst bed in reactor 214 is divided into two zones with the upper zone comprising about 50 per cent and the lower about 50 per cent of the total volume in the reactor.

Charge stock (2) is drawn from a source, not shown, through line 279, heated in furnace 280 to a temperature of about 780 F. and discharged from furnace 280 into line 281. Recycle gas drawn from holder 226 through pipe 294 is heated in furnace 295, passed through pipe 296 under control of valve 299 and mixed with charge stock (2) to form charge mixture (2) in line 281. Charge mixture (2) passes through line 281 to manifold 282 and thence to inlet 285 under control of valve 291 and its associated distributor which is paired with the aforesaid inlet 271 for charge mixture (1). Charge mixture (2) passes through the lower reforming zone which is about 50 per cent of the total volume of the reactor. Charge mixture (2), enters the reactor at a temperature of about 1000 F.

Reactor 214 is provided with throttling devices 373 and 374 such as throttle valves whereby the volume of reformate issuing from the upper and lower reforming zones is controlled. The reformate from the upper or top reforming zone passes through throttling device 373 line 375 through cooler 377 and line 379 into gas-liquid separator 38]..

The condensed hydrocarbons in separator 381 are withdrawn therefrom to after-treatment, distillation, storage and distribution through line 383. Water removed from the catalyst in the top 30% of upper reforming zone of reactor 214 and condensed in cooler 37'] is removed from line 399 under control of valve 398. The uncondensed gases escape through pipe 385, through pipe 391 under control of valve 393 to recycle gas pipe 395. When desired, all or a portion of the gases escaping from separator 381 can be vented to a recovery plant not shown through pipe 387 under control of valve 389.

The eflluent from the lower reforming zone or bottom section of reactor 214 passes through throttling device 374, line 376, cooler 378 and line 380 into gas-liquid separator 382. The condensed hydrocarbons in separator 382 are withdrawn therefrom to after-treatment, distillation, storage and distribution through line 384. The uncondensed gases escape from gas-liquid separator 382 through pipe 386 and pass through pipe 392 under control of valve 394 to gas recycle pipe 395. When desired, all or a portion of the gases escaping from separator 382 can be vented to a recovery plant not shown through pipe 388 under the control of valve 390. The

combined gases from

separators

382 and 381 pass through.

line 395 to gas drier 396 where residual water vapor is removed from the gases. From drier 396 the gases pass through line 397 to storage sphere 2.26 where it is available for use as recycle gas.

As will be observed by those skilled in the art. the charge. mixture inlet temperature, the catalyst inlet temperature, the ratio of the vapor stream heat capacity to the catalyst stream heat capacity were correlated so that, although the catalyst entered the reactor carrying more than 0.5 weight per cent loosely-bound oxygen and/ or water as defined hereinbefore, the temperature of the catalyst in the lower 97 volume per cent of the upper reforming zone was less than F. below the temperature of the vapor surrounding the catalyst and the catalyst in the lower 80 per cent of the upper reforming zone contained less than 0.7 preferably less than 0.5 weight per cent water. Consequently, maximum reforming yields were obtained without catalyst pretreatment.

I claim:

I. In the method of reforming hydrocarbon mixtures which comprises introducing a particle-form reforming catalyst containing in excess of 0.7 weight per cent looselybound oxygen and water and having a temperature of 100 to about 1200 F. into a reactor at about 800 to about 1080 F. and about 15 to about 600 p. s. i. a., passing said reforming catalyst through said reactor from a catalyst inlet to a catalyst outlet, introducing a vaporous mixture comprising hydrocarbon vapors and gaseous heat carrier at a temperature of 100 to about 1100 F. into said reactor, passing said vaporous mixture from a vapor inlet to a vapor outlet counter-current to said moving catalyst, withdrawing catalyst from said reactor, regenerating said withdrawn catalyst to obtain regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water, recycling said regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water to said reactor, withdrawing vapors from said reactor and recovering reformed hydrocarbons from said withdrawn vapors, the improvement which comprises regulating the temperature and amount of said catalyst and the temperature and amount of said vaporous mixture introduced into said reactor (1) to provide a vapor stream heat capacity to catalyst stream heat capacity ratio of at least 1.25 when the catalyst inlet temperature is less than 800 F. and at least 0.02 when 1 4 thecatalyst inlet temperature is greater than 800F1, and (2) to provide a minimum average temperature of in the 20-30 volume per cent of catalyst bed contiguous to said catalyst inlet, T being the residence time in minutes of the catalyst in said 20-30 volume percentofsaid catalyst bed contiguous to said catalyst inlet, and. (3). to provide catalyst temperatures in the 97 to 99=volurne per cent of catalyst bed contiguous tosaid catalyst outlet notmore than 5 F. below the temperatures of the vapors surrounding said catalyst.

2. In the method of reforming hydrocarbon mixtures which comprises introducing a particle-form reforming catalyst containing in excess of 0.7 weight per cent'loosely bound oxygen and water and having a temperature of 100 to about 1200 F. into a reactor at about 800' to about 1080 F. and about 15 to about 600 p. s. i. a., passing said reforming catalyst downwardly as a substantially compact column through said reactor from a catalystinlet to a catalyst outlet, introducinga vaporous mixture comprising hydrocarbon vapors and gaseous heat carrier at a temperature of 100 to about 1100 F. into said reactor, passing said vaporous mixture from a vapor inlet to a vapor outlet counter-current to said moving catalyst, withdrawing catalyst from said reactor, regenerating said withdrawn catalyst to obtain regenerated catalyst containing in excess of' 0.7 weight per cent loosely bound oxygen and water, recycling said regenerated catalyst containingin excess of 0.7weight per cent loosely bound' oxygen and water to said reactor, withdrawing vapors from said reactor and recovering reformed hydrocarbons from said withdrawn vapors, their'nprove ment which comprises regulating the temperature and amount ofsaid catalyst and the temperature and amount of said vaporous mixture introduced into said reactor, (1)' to provide a vapor stream heat capacity to catalyst stream heat capacity ratio of at least 1.25 when the catalyst inlet temperature is less than 800 F. and at least 0.02 when the catalyst inlet temperature is greater than 800 F.', (2) to provide a minimum average temperatureof in the 20-30 volume per cent of catalyst bed contiguous to said catalyst inlet, T being the residence time in minutes of the catalyst in said 20-30 volume per cent of said catalyst bed contiguous to said catalyst inlet, and (3) to provide catalyst temperatures in the 97 to 99 volume per cent of said catalyst column contiguous to said catalyst outlet not more than 5 F. below the temperatures of the vapors surrounding said portion of said catalyst column.

3. In the method of reforming hydrocarbon mixtures which comprises flowing downwardly a particle-form reforming catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water and having a temperature of 100 to about 1200 F. as a substantially compact column of particle-form reforming catalyst through a reactor at a temperature of about 800 to about 1080 F. and a pressure of about 15 to about 600 p. s. i. a. from a catalyst inlet to a catalyst outlet introducing a vaporous mixture comprising hydrocarbons and a gaseous heat carrier into said reactor at a vapor inlet intermediate said catalyst inlet and outlet to form an upper reforming zone above said vapor inlet and a lower reforming zone below said vapor inlet, flowing a portion of said vaporous mixture upwardly through said upper reforming zone countercurrent to said downwardly flowing column of catalyst to a vapor outlet in said upper reforming zone, flowing the balance of said vaporous mixture downwardly through said lower reforming zone concurrently with said downwardly flowing catalyst column to a vapor outlet in said lower reforming zone, withdrawing catalyst from said lower reforming zone, regenerating said withdrawn catalyst to obtain regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water, recycling said regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water "to said upper'reforming zone, withdrawing vapors from said upper reforming zone, withdrawing vapors from said lower reforming zone, and recovering reformed hydrocarbons from said withdrawn vapors, the improvement which comprises regulating the temperature and amount of said catalyst introduced into said reactor and the temperature and amount of said vaporous mixture introduced into said upper reforming zone to provide a ratio of vapor stream heat capacity to catalyst stream heat capacity of about 0.05 to 100 and to provide in the 20 to 30 volume per cent of said catalyst column in said upper reforming zone contiguous to said catalyst inlet a minimum average temperature of where T is the catalyst residence time in minutes in said 20 to 30 volume per cent of said catalyst column in said upper reforming zone and to provide catalyst temperatures in the 97 to 99 volume per cent of the catalyst bed contiguous to said vapor inlet not more than F. below the temperatures of the vapors surrounding said catalyst.

4. In the method of reforming hydrocarbon mixtures which comprises flowing downwardly as a substantially compact column a particle-form reforming catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water and having a temperature of 100 to about 1200 F. through a reactor at a temperature of about 800 to about 1080 F. and a pressure of about 15 to about 600 p. s. i. a. from a catalyst inlet to a catalyst outlet, introducing a first vaporous mixture comprising hydrocarbons and a gaseous heat carrier into said reactor at a first vapor inlet intermediate said catalyst inlet and said catalyst outlet, introducing a second vaporous mixture comprising hydrocarbons and a gaseous heat carrier into said reactor at a second vapor inlet intermediate said first vapor inlet and said catalyst outlet and adjacent to said first vapor inlet, flowing said first vaporous mixture upwardly counter-current to said downwardly flowing catalyst from said first vapor inlet to a first vapor outlet in the region of said catalyst inlet, flowing said second vaporous mixture downwardly concurrently with said downwardly flow catalyst from said second vapor inlet to a second vapor outlet in the region of said catalyst outlet, withdrawing catalyst from said catalyst outlet, regenerating said withdrawn catalyst to obtain regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water, recycling said regenerated catalyst containing in excess of 0.7 weight per cent loosely bound oxygen and water to said catalyst inlet, withdrawing vapors from said first and second vapor outlets, and recovering reformed hydrocarbons from said withdrawn vapors, the improvement which comprises regulating the temperature and amount of said first vaporous mixture introduced into said reactor (1) to provide a vapor stream heat capacity to catalyst stream heat capacity ratio of at least 1.25 when the catalyst inlet temperature is less than 800 F. and at least 0.02 when the catalyst inlet temperature is greater than 800 F., and (2) to provide a minimum average temperature of References Cited in the file of this patent UNITED STATES PATENTS 2,324,165 Layng et al. July 13, 1943 2,335,610 Plummer Nov. 30, 1943 2,338,573 Creelman Jan. 4, 1944 2,364,453 Layng et al. Dec. 5, 1944 2,366,372 Voorhees Jan. 2, 1945 2,419,517

Eastwood Apr. 22, 1947

Claims

1. IN THE METHOD OF REFORMING HYDROCARON MIXTURES WHICH COMPRISES INTRODUCING A PARTICLE-FORM REFORMING CATALYST CONTAINING IN EXCESS OF 0.7 WEIGHT PER CENT LOOSELYBOUND OXYGEN AND WATER AND HAVING A TEMPERATURE OF 100* TO ABOUT 1200* F. INTO A REACTOR AT ABOUT 800* TO ABOUT 1080* F. AND ABOUT 15 TO ABOUT 600 P. S. I. A., PASSING SAID REFORMING CATALYST THROUGH SAID REACTOR FROM A CATALYST INLET TO A CATALYST OUTLET, INTRODUCING A VAPOROUS MIXTURE COMPRISING HYDROCARBON VAPORS AND GASEOUS HEAT CARRIER AT A TEMPERATURE OF 100* TO ABOUT 1100* F., INTO SAID REACTOR, PASSING SAID VAPOROUS MIXTURE FROM A VAPOR INLET TO A VAPOR OUTLET COUNTER-CURRENT TO SAID MOVING CATALYST, WITHDRAWING CATALYST FROM SAID REACTOR, REGENERATING SAID WITH DRAWN CATALYST TO OBTAIN REGENERATED CATALYST CONTAINING IN EXCESS OF 0.7 WEIGHT PER CENT LOOSELY BOUND OXYGEN AND WATER, RECYCLING SAID REGENERATED CATALYST CONTAINING IN EXCESS OF 0.7 WEIHT PER CENT LOOSELY BOUND OXYGEN AND WATER TO SAID REACTOR, WITHDRAWING VAPORS FROM SAID REACTOR AND RECOVERING REFORMED HYDROCARBONS FROM SAID WITHDRAWN VAPORS, THE IMPROVEMENT WHICH COMPRISES REGULATING THE TEMPERATURE AND AMOUNT OF SAID CATALYST AND THE TEMPERATURE AND AMOUNT OF SAID VAPOROUS MIXTURE INTRODUCED INTO SAID REACTOR (1) TO PROVIDE A VAPOR STREAM HEAT CAPACITY TO CATALYST STREAM HEAT CAPACITY RATIO OF AT LEAST 1.25 WHEN THE CATALYST INLET TEMPERATURE IS LESS THAN 800* F. AND AT LEAST 0.02 WHEN THE CATALYST INLET TEMPERATURE IS GREATER THAN 800* F., AND (2) TO PROVIDE A MINIMUM AVERAGE TEMPERATURE OF