BE460889A - - Google Patents

Description

       

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  "Method and apparatus for bringing solids and gases into contact".



   The present invention relates to a process and apparatus for contacting a solid material in finely divided form with gaseous products and more particularly relates to a process and apparatus in which a solid material in finely divided form is mixed. to, a gaseous fluid and the resulting mixture is sent through. to a treatment area,
The invention finds application in industrial operations of various types in which finely divided solids are mixed with a stream of gas and vapor in a continuous manner with a view to causing physical or chemical changes in the gases or solids or both.



   Examples of operations in which the solids are subjected to the action of gases and in which phases of the invention can be applied are: the low temperature carbonization of coal, the production of gas at water from coal, distillation of wood, oily shale or coal, processing of ores such as reduction and roasting of various metal ores, drying of solid materials, etc.



   Examples of non-catalytic operations in which the gases are subjected to the action of solids and in which certain phases of the invention find their application are:
The oxidation of gases by various solid oxides, the separation and purification of gases from solid absorbents such as activated carbon and oxide gels as in air conditioning, and the recovery of vapors out of gas' as in the recovery of gas solvents in dry cleaning and painting establishments, the recovery of gasoline constituents from natural gas, or refinery gas that has not been cracked, etc.,

   the separation of gases or vapors by selective absorption comprising the selective removal of high boiling point hydrocarbons from low boiling point hydrocarbons.



   A third class of process in which the invention

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 finds its application is that in which finely divided materials act as a catalyst to cause gas reactions. We can mention as different examples
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 organic reactions involving oxidation, reduction, chlora, un-hydration, dehydration, etc. and more
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 particularly different hydrocarbon reactions in which solid catalysts or treatment agents
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 can be employed, as in crakin, hydropnation, dehydrogenation, polymerization, alkylation, dealkylation, isom.4risp., tion, aromatization, desulphurization, synthesis of hydrocarbons from therein. carbon monoxide, and hydrocene, etc.

   The invention in its more particular phases is directed especially to those processes in which the solid material after passing through the processing zone is separated from the gas and vapor stream and is returned to the processing zone. It is applied by-
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 particular to operations in which it is desirable (1) to reactivate or regenerate the catalyst powders before
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 to return these to the process, as in the catalytic conversion of hydrocarbon oils or steam or (3) to quickly add or remove heat from the process zone in which the reactions take place strongly exothermic or endothermic.



   It is a general object of the present invention to provide a method and apparatus for contacting solids with gases, comprising a mixture of finely divided solids in a gas stream and transporting the solids. resulting mixing through a process zone in a continuous fashion, the apparatus being simpler and more economical to construct and operate. operate and the process is not subject to the operating difficulties encountered heretofore in operations of this kind.



   Other more particular objects and advantages of the invention will emerge from the more detailed description which follows.



   The invention as a whole comprises a complete unitary operation involving reaction and regeneration treatment of the pulverized material in a closed circuit and also embraces certain combinations and sub-combinations of operations and elements, as described above. specified for resale
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 dications ..



   The invention will be described by way of example with particular reference to the catalytic cracking of petroleum oils, to which it has been found particularly applicable, but it is of course, from the preceding description, that The invention in its broadest sense has a more general application.



   For an understanding of the invention, reference will now be made to the accompanying drawings in which:
FIG. 1 is a schematic view in elevation: of a part of the apparatus according to the present invention,
Fig. 1A is an extension of fig.l, showing the remainder of the apparatus.
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  In the figure of the drawing the reference numeral 10 denotes a charging line through which the oil to be cracked is introduced into the system. This oil can be clean condensate such as gas oil or a residual material such as improved or reduced residue.



   The oil introduced into the system through line 10 first passes through a heat exchanger 11 in which the oil
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 goes into a heat exchange relationship with spent regeneration gases, as will be described below. Oil coming from

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   the heat exchanger 11 passes through line 12 to a second heat exchanger 13 where it is further heated by the exchange of heat with pulverized catalytic material removed from the regeneration zone described later, L ' oil which has passed through the heat exchanger 13 is transferred through the pipes 14 and 15 to a vaporization coil 16 ', located in an oven 17,

   where it is heated rapidly to a temperature sufficient to vaporize at least a significant portion of the oil. If desired, steam or other off-gas can be introduced into the oil through line 18 before or during its passage through vaporization coil 16 to facilitate vaporization of the oil.



   The products coming from the vaporization coil 16 can pass through the transfer line 19 to a separator 21 to separate the vapors from the unvaporized residue. Steam or other additional release agent may be introduced into separator 21 through line 22. The unvaporized residue separated in separator 21 may be removed therefrom through line 23. Vapors released into separator 21 may be removed therefrom. separator 21 exit at the top through line 24.



   In cases in which the oil to be treated is clean condensate, the separator 21 can be omitted or the oil coming from the vaporization coil 16 can bypass the separator 21 via line 25.



   The vapors released in the separator 21 constitute the feed material for the catalytic cracking oil. These vapors can pass through conduits 24 and 25 to conduit 27 where the vapors mix into a sprayed catalytic material introduced into the conduit in a manner described later. Dispersion, resulting from oil vapors. and pulverized material passes through line 27 to a cracking vessel 89 (see figlA).



   In some cases it is desirable to further heat the oil vapors from separator 21. In such cases, the vapors from line 24 may be passed through a superheater coil 31 or other heater to receive the desired heat. ..



   The amount of catalyst introduced into the oil vapors going into the reaction chamber 29 can vary within wide limits depending on a number of factors such as the characteristics of the oil to be caracked, the activity of the oil. catalyst and the degree of conversion desired, in general the amount of catalyst thus introduced can be within the limits of 0.5 20 parts of catalyst per part of oil, by weight *
The bottom of the reaction chamber may be provided with a perforated plate 32 through which the dispersion passes. The function of this plate is to evenly distribute the dispersion throughout the cross section of the cracking vessel.



   The cracking vessel is made in such dimensions that the desired conversion is achieved at relatively low speeds such as 0.5 to 10 feet per second.



    Because of the relatively low velocities at which the gases flow through the circuit, the powder tends to settle out of the gas. It is presumed that there is a considerable slip between the solid particles and the vapors, so that a continuous mixing of the gas and the solids is obtained. In addition, the density of the suspension or dispersion

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 'in the zone. of reaction will be much greater than the density of the stream passing to the reaction zone or the relative proportions of catalyst and oil vapors introduced into the zone.

   The density of the mixture should be at least twice as great as that of the current passing to the zone: In other words, the velocity of the gases passing through the reaction orane is preferably controlled, as far as concerns the size and density of the catalyst particles, so that the residence time of the catalyst particles in the cracking zone in such a case is significantly longer than the residence time of the oil vapors.



   For example, while the residence time of oil vapors may be on the order of 5 to 50 seconds, the residence time of solid particles in the cracking zone may be on the order of 10 seconds at hour or more. As a result, a smaller and more compact reaction vessel can be employed for a given capacity cracking unit, and the amount of sprayed catalyst circulating can also be reduced.



   The velocity of the oil vapors passing through the cracking zone, however, is preferably sufficient to prevent complete deposition of the powder so that the vapors from the cracking can be used to remove the pulverized material from the cracking zone. .



   The suspension of oil and catalyst vapors which have passed through the cracking vessel is removed therefrom through line 32 having a Venturi nozzle 33 and is sent to a first cyclone separator 34 in which the greater part of the powder is removed from the oil vapors. The catalyst separated in the first cyclone separator
34 is drained into bottom 35, which is preferably of sufficient size to provide sufficient reserve to last 5 to 15 minutes. The catalyst discharges from hopper 35 through a suitable valve 36 into a stream of off-gas such as water vapor passing through the line.
37 to a cyclone separator 38 forming the upper section of a second catalyst hopper 39.

   The water vapor separated in the separator 38 is removed therefrom through the pipe
41 and is sent by means of a steam injector 42: the inlet of the cyclone separator 34, through line 43.



   The reintroduction of the catalyst into a stream of water vapor in line 37 serves primarily to remove volatile oil constituents which may be retained in the catalyst after separation. Instead of water vapor, other inert gases such as nitrogen, carbonic acid, complete combustion gases, etc. can be used.



   The vapors separated in the first cyclone separator
34 and from which most of the pulverized material has been removed, pass through a line 44 to a second cyclone separator 45 where the vapors are subjected to further purification. The second cyclone separator 45 can advantageously be constructed in the upper section of the catalyst hopper 39. The catalyst separated in the second cyclone separator 45 can then fall directly into the catalyst hopper 39. The cracking vapors coming from the second cyclone repairer 45 are sent via line 46 to a third cyclone separator 47 in which a further removal of pulverized material from the sputtering products is obtained.

   The catalyst separated in the third cyclone separator 47 is discharged through line 48, the end of which ends.

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1 in the lower part of the catalyst hopper 39 at a point below the level of the catalyst maintained therein. The cracking vapors are removed from the third cyclone separator 47 through line 49 and sent to a suitable fractionation or rectification system (not shown) for the separation of the desired motor fuel products from the insufficiently heated components. cracking and normally gaseous constituents. The fractionation or rectification system can be of any usual form and for greater simplicity it has not been shown in the drawing.



   Although a group of three cyclone separators operating in series to separate the pulverized catalyst from the vapors has been shown, it should be understood that other equivalent devices for effecting the separation of solids from gases may be employed if. we want it,
In cases where the catalyst is not completely removed from the oil vapors before they pass through the fractionation tower, a narrow fraction of the initial condensate formed in the fractionation tower, containing the catalyst - residual lyser, can be separated from the remainder by means of an expulsion plate or a similar device and put back into circulation through line 51 to the inlet of the first cyclone separator 34.



   The catalyst collected in the hopper 39 is discharged into a vertical pipe 52 of sufficient height to send the catalyst into a stream of regeneration gas under a pressure at least sufficient to overcome the drop in pressure through the regeneration circuit. .



   One of the important phases of the present invention is the use of a catalyst column of sufficient height to produce a base pressure which introduces the catalyst into the stream of reeneration gas.



   It has been found that under suitably revelated conditions the pulverized material can be made to flow as a fluid and conform to many laws of physics of a fluid, in order to ensure that As the material flows as a fluid, measures are usually necessary to prevent the sprayed material from agglomerating in the pipe 53. This can be easily achieved by introducing a small amount. of a fluidizing gas at one or more points spaced along the length of the vertical pipe, by conduits 55, 56 and 57.



   The fluidization gas introduced through the pipes 55,
56 and 57 is preferably one. inert gas such as water vapor, carbonic acid, spent combustion gases, nitrogen, etc.



   The lower end of the vertical pipe 52 is provided with a suitable valve 58 to control the amount of catalyst delivered by the tuvau. A conventional damper valve, comprising a damper with an opening which can be moved to adjust the size of the orifice through which the powder passes, is well suited for this purpose although other types of valves can be used * This valve can be operated by hand or automatically, for example by the level in the hopper 39 * The valve is shown in the drawing schematically as being controlled by an instrument
59 under the action of the level in the hopper 39,

   
As a safety precaution to prevent the possibility of regeneration gas passing upwards through the

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 vertical pipe and its mixture with the oil vapors, a second safety valve 61 is preferably provided. This valve can be actuated automatically to close when the level of the powder in the hopper 39 drops below a determined point,

   or it can be established so that it is
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 automatically close when uBfla rression below valve 58 is close to or equal to the pressure above valve 58.
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 The spent catalyst separated from the mrsokinel product is introduced into a stream of regeneration gas which can
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 be air or air diluted by means of a controlled inert such as water vapor, carbonic acid, nitrogen, etc., introduced into the system by driving 65.

   The regeneration gas is put by means of a fan or a.
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 another similar device (not shown) under sufficient pressure to discharge the stream of regeneration gas and catalyst a. through the regeneration circuit. A flow of the regeneration gas and of the catalyst to be regenerated is formed in the line 66 and sent through the line 67 into
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 a regeneration chamber 68 (see fig * 1 which is preferably similar in construction to that of the cracking chamber 39. The regeneration chamber 68 is also preferably of such dimensions that the flow of the slurry through the room is relatively slow, so that it
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 produces a considerable bond between the powder and the gases.



  The speed of the gases, however, is greater than the average deposition rate, so the gases can be used to transport the catalyst through the regeneration system. As a consequence, as in the cracking chamber 29, the residence time of the catalyst in the regeneration zone
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 is significantly greater than the residence time of the regeneration <:, 1 "Z thereof.

   The slurry of revered catalyst and regeneration gas introduced into regeneration chamber 68 is mixed with the cooled regenerated catalyst introduced through line 69 as will be described in the following.
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 The amount of regenerated catalyst introduced into the regeneration chamber is adjusted to control the temperature in the regeneration chamber to be below a value which would permanently decrease the activity.
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 of the catalyst. During its passage through the rg-en9rqtion.t chamber the catalyst is subjected to an oxidation reaction to burn the carbon base formed on it during the cracking operation.

   The slurry of regenerated catalyst and az, after passing through regeneration chamber 68 is conducted through pipe 71 to a first cyclone separator 72 in which most of the regenerated catalyst is separated. regeneration gas.



   The density of the vapor passing through line 71 can be measured by the pressure drop. through a Venturi tube 73 placed in this pipe and this measurement can be
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 used to adjust the flow through the reo: enerH. 68.



  The regenerated catalyst separated in the first cyclone separator 7P can be discharged directly into a catalyst hopper 74. For this purpose the cyclone separator 72 can be constructed in the upper part of the catalyst hopper, as shown. . The reenergation gas is removed from the first separator 72 through line 75 and is sent to a
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 second cyclone separator 76 in which further catalyst removal from the regeneration gas is produced. The catalyst separated in the second cyclone separator 76 is discharged through the

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 conduit 77 having its lower end embedded below the level of the catalyst ma contained in the catalyst hopper 74.



   Regeneration gas from second cyclone separator 76 passes through line 78 to third cyclone separator 79 where a further removal of regenerated catalyst from the gas is obtained.



   The catalyst separated in the third cyclone separator 79 is discharged through line 81 into the catalyst hopper 74 at a point below the level of the catalyst maintained therein. By embedding the ends of catalyst discharge lines 77 and 81 below the level of the catalyst in hopper 74, a closure is maintained preventing gas from the catalyst hopper from passing in a reverse direction through the second. and the third cyclones.



   The regeneration gas from the third cyclone separator 79 is sent via line 82 to the heat exchanger 11, in which it passes into a heat exchange relationship with fresh oil to be subjected to cracking, as has been done. previously described. The advantage of the heat exchanger 11 is not only to heat the oil but also to cool the regeneration cells to a point where they can be passed to an electrical precision for the complete removal of the material. The regeneration gas may, for example, be cooled as it passes through the heat exchanger 11 from a temperature of 1000 to a temperature of 700 before passing through the electric precipitator.



   After passing through the heat exchanger 11, the regeneration gas is transferred through a line 83 to a pre-. electric precipitator 84 for further purification of the gas before sending it to the armosphere. This electric purifier can be of any conventional construction. The catalyst precipitated in the electrical precipitator 84 is discharged through line 85 into the catalyst hopper 74 at a point below the level of the material therein. After having been substantially purified by means of the cyclone separators and the electric precipitator, the regeneration gas is discharged from the system via line 86.



  This gas can, if desired, be sent to a suitable waste heat boiler or other heat recovery system for the removal of the heat before it leaves to the atmosphere *
The regenerated catalyst collected in the hopper 74 leaves continuously in two vertical pipes 87 and 88. The pipe 88 must be of sufficient height to produce at its lower part sufficient pressure to introduce the catalyst into the stream of oil vapors. to be subjected to the cracking, which in turn must be at least sufficient to overcome the pressure drop across the cracking equipment.



   The vertical pipe 87 must also be of sufficient height to develop at the base an adequate pressure to return the catalyst to the regeneration zone.



   In order for vertical pipes to act effectively in building pressure, it is important that the catalyst held therein is in a free flowing state. For this purpose a fluidization gas can be re-introduced into one or. several places spaced in the vertical pipes 87 and 88 by conduits 90 to 93 inclusive and respectively 94 to 96 inclusive.



   The catalyst held in the vertical pipe 88 is des-

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 keen to be sent back to the crackling circuit. For this purpose the lower part of the pipe 88 can be provided with a valve
97 to regulate the flow of catalyst in the flow of oil vapors from line 27.



   Valve 97 may be manually adjusted but is preferably controlled to maintain the desired catalyst-to-oil ratio as measured by Venturi tube 33.



    As also shown, a second safety valve 99 may be placed at the bottom of vertical pipe 88 to prevent the possibility of oil vapors from line 27 to pass through pipe 88 and to mix with the regeneration gas. For this purpose the valve 99 can be set so as to close automatically when the level in the pipe 88 or the hopper
74 drops below a specified point or when the pressure difference between opposing sides of valve 97 reaches a specified minimum.



   In view of the illustration, the valves located at the lower part of the pipe 88 and the other vertical pipes have been shown as a simple register valve, which is the preferred form. It may, however, be desirable in some instances to provide a valve which is capable of causing agitation of the spray material passing through it. Such a valve may for example comprise a rotating propeller such as a star feeder or it may be in the form of an endless screw operated to feed the catalyst at the desired speed.



   The catalyst collected in the vertical pipe 87 is intended to be returned to the regeneration chamber to adjust the temperature there.



   For this purpose a part of the catalyst collected in the vertical pipe 87 can be sent through the valve 103 and the pipe 104 to the condenser 13 where it passes in heat exchange with fresh oil to be distilled and subjected to cracking and returns from there to the regeneration area
68.If desired, part of the catalyst sent to the regeneration zone can bypass refrigerant 13 by means of valve 105 and line 106.If desired, air or other regeneration gas can be introduced through line 107 into the stream of regenerated catalyst circulated in coolant 13 or through line 108 into line 106 bypassing the coolant, or into both lines, to act as a vehicle for the catalyst sent,

   
By controlling the relative amounts of cooled regenerated catalyst and uncooled regenerated catalyst returned to the regeneration chamber through lines 104 and
106 respectively, careful control of the temperature in the regeneration chamber can be achieved.



   In many cases, the. amount of heat which must be removed from the catalyst during regeneration is in excess of that required to heat the oil to the desired temperature. Further, it is convenient from a practical point of view to send the oil to the cooling coil. vaporization 16 at a uniform temperature regardless of the amount of heat liberated in the regeneration zone.



   As shown in the drawing, part of the oil can, after passing through the heat exchanger 13, be sent through line 111 to a waste heat boiler
112 where the oil can be cooled and water vapor can be produced. After moving to. through the boiler

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112 with waste heat, the oil can be returned to the inlet of the heat exchanger 13 by means of a pump 113 and a pipe 114.



   By connecting it. As the amount of oil passes through the waste heat boiler 112, a uniform temperature of the inlet to the vaporization coil 16 can be maintained without affecting the amount of cooling removed in the catalyst coolant 13. ,
From the foregoing description, it follows that all the pressure necessary to introduce the catalyst into the stream of reaction gas and of regeneration gas is obtained by means of vertical columns of catalyst and not by the use of mechanical devices.



   The examples which follow will be useful for the understanding of the invention, but it is understood that the values and the conditions cited are by way of example and nbn by way of limitation, @ Reduced raw material to be treated, introduced into the system through line 10, can be heated beforehand in heat exchanger 11 from an initial temperature of 400 to 450 F, up to a temperature of 4500 to 500 F., and in the refrigerant at. catalyst 13 at a temperature of
650 to 750 F, usually 700 F, before passing to vaporizer 16. The oil as it passes through vaporizer coil 16 is heated to a temperature of 800 to
900 F, usually 850 F.

   The oil then passes from the spray coil 16 to the separator, where 60 to 95% passes upward as vapors. The vapors from the separator pass through a superheater where they are heated to a temperature of 8500 to 950 F, preferably 900 F.



   The value of the pressure applied to the oil vapors must be sufficient to overcome the resistance of the cracking circuit and of the fractionation system * In an industrial-sized cracking apparatus employing the type of reaction vessel described above. , a pressure of one atmosphere is usually sufficient.



   The catalyst introduced into the oil vapor stream can be any active cracking catalyst, such as naturally active or activated clay and particularly acid-treated clays, or it can be gels. synthetic or other absorptive catalysts of the same or different chemical composition, such as synthetic silica-alumina gels, silica-magnesia gels, and mixtures thereof.



   The amount of catalyst introduced into the oil vapors can range from 0.1 to 20 parts by weight of catalyst per part of oil. When using acid-treated bentonite clays, the ratio may be 4 parts catalyst per part oil. The temperature of the catalyst introduced into the oil stream is preferably substantially the final regeneration temperature which may be on the order of 1000 to 1100 F, so that the resulting equilibrium temperature of the catalyst and oil vapors, can be between 900 F and 1000 F.



   The height of the vertical pipe 88 from which the catalyst is fed into the oil stream should be sufficient to develop a pressure charm suitable for introducing the catalyst into the oil vapor stream. In a particular case where activated clay is used as a catalyst and where the column is suitably fluidized by

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 Addition of 0.82: of fluidizing along the length of the vertical pipe, 4 to 6 feet of fluidized catalyst is required for each pound of pressure.

   In the particular case where the oil vapors are at a pressure of one atmosphere and the pressure at the top of the vertical pipe 88 is on the order of 3 pounds per square inch, the minimum height of the vertical pipe will be of the order of 50 feet and is preferably 100 feet or more. In order to ensure proper adjustment of the inlet of catalyst to the oil stream, it is necessary to maintain a pressure difference across the adjustment valves of 2 to 5 pounds per square inch.



   The speed of the oil stream passing through the cracking zone 29 is preferably less than 8 feet per second and may for example be on the order of about 2 feet per second. When these low speeds are maintained, the concentration of catalyst in the reaction zone is significantly greater than the concentration of catalyst in the stream to the reaction zone. When, for example, the vapor speed d is employed. For 2 feet of oil per second, the concentration of catalyst in the cracking zone can be up to 10 pounds per cubic foot of space. reaction. Under these circumstances, the residence time of the catalyst in the reaction zone may be about 3 minutes, while the residence time of the oil vapors will be on the order of 10 seconds.



   The cracked vapors and spent catalyst pass to the first cyclone separator at a temperature of
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 850 to 9500F. The pressure drop from the point where the -cata- lyser is introduced into the oil vapors through the cracking chamber to the first cyclone where the catalyst is separated can be on the order of 5 pounds per inch. square.



  In this case, the oil vapors going to the fractionation tower will be under a positive pressure of about 10 pounds per square inch. As a result, no additional pressure needs to be applied to effect the subsequent treatment of the oil. -fractionation and stabilization.



   The height of the vertical pipe 52 which introduces the cal- lyser into the regeneration gas should be sufficient to produce at the bottom a pressure charge which introduces the spent catalyst into a stream of regeneration gas which in turn should. be under sufficient pressure
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 health to transport the mixture through the regeneration circuit.

   This pressure may for example be on the order of 12 pounds per square inch. In such a case, when the pressure on the hopper 39 is on the order of 10 pounds per inch.
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 this square, the height of the vertical pipe 5? can be of the order of 30. 60 feet to ensure a suitable difference b. tra-
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 towards the control valves, The catalyst and the reeneration flow going to the regeneration chamber 68 are brought from the cooled atlyseur r'jén! oeµ recirculated by means of the vertical pipe 87 towards the refrigerant 13 in pro-
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 conditions such that the equilibrium temperature of the median introduced into the regenerator is of the order of 900 F.

   The temperature is affected, however, by the amount of catalyst recirculated through the coolant and the amount con-
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 turning the ZA-friz-4rant, to prevent the temperature in the reaction vessel from exceeding a point which would permanently impair the activity of the catalyst. In the activated diar- iles, previously mentioned, the maximum allowable temperature of the regeneration zone can be of the order of

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 EMI11.1
 I0500F. The velocity of the r2cen,; ra, tion gas passing through the regeneration zone may be substantially the same as that of the
 EMI11.2
 oil vapors passing through the cracking zone, i.e. 1
8 feet per second ,.

   Under these conditions, the residence time of the catalyst in the regeneration zone can be from 1 to
5 minutes and the residence time of the regeneration gas in the regeneration zone can be 2 to 60 seconds.



   The suspension of regenerated catalyst and regenerated gas. ration is separated in the cyclone separators and the electric precipitators at a temperature close to the temperature
 EMI11.3
 ture obtained during regeneration, a-% can be 1 in the order of 1000 to 1100 F, as previously described.
The height of the vertical pipe 87 to bring the catalyst
 EMI11.4
 through the refres-irant 13 in the unregenerated catalyst stream going to the regenerator must be sufficient to overcome the pressure drop b across the refréo'irant, 1a. regeneration chamber and connecting ducts.



   It may be useful to mention at this point that the growth of the powder from the highest point to the same point is made possible by the fact that the current density in the return branch is lower than in the return branch. The difference in pressure between the top and bottom branches can be expressed by the formula DP = dh where d is the density of the material and h is the distance from the top to the bottom. In order for the powder to circulate in the system,
 EMI11.5
 dlhldmust be greater than dah2¯J if d hi is the density and height of the material in the / return branch. d2 is reduced by introducing reaction or regeneration gas to one side of the circuit.

   The same result can be achieved
 EMI11.6
 also Bar Inapplication of cbalaur on one side will reduce 1 '"TTaeacerKTante ei D2 H2 hé ensife the' height Ge 'la ma laoraHche
In order for the pulverized matter to seek its own level and behave otherwise like a liquid, the solid matter must be in a finely divided form and each particle
 EMI11.7
 should preferably be surrounded by a zaz film. Particle sizes smaller than 200 mesh are usually preferred.
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  Although the invention has been applied to the conventional cracking of hydrocarbon oils, which operation in this area has found its specific application, the same general procedural steps apply to other types of oil reaction. hvdrocgr- bures with or without the presence of an external gas such as hy droene, although the specific operating conditions
 EMI11.9
 They usually ignore what has just been described.



  For example, in the zo11ne amendment to improve the octane number, the catalyst may be an alumina or ra, nc, sie carrier, preferably in an absorptive form, containing dss oxides or sulfides. mtau'x 'found in III VIII, preferably metals du. rump VI. Temperature
 EMI11.10
 can range from z 1400OF, and the contact time can vary from? at 60 seconds ,. The pressures employed can range from atmospheric pressure to 400 pounds per square inch.



   With regard to pressure, it should be understood that the system can operate under any pressure desired, since vertical pipes are employed to generate sufficient pressure to overcome the pressure drop in the system.
 EMI11.11
 In the case of 0 "ll ', byàro7ène is employed for the treatment of measures are necessary to recirculate the hy-
 EMI11.12
 drr-.ne in excess. '

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When dehydrogenating gases are used, the same cycle of catalysts begins! is used only for amendment.



  The temperature can be a little higher, from -700'0 1400 F, and the pressure can be a little lower and can range from below atmospheric pressure to .200 pounds per square inch. -
In the alkylation of olefins with branched chain paraffins, active cracking catalysts may be employed. A particularly suitable catalyst is a complex sodium aluminum chloride. The temperature can be in the range of 500 to 3000 pounds per square inch.



   In hydrocarbon treatments involving isomerization of straight chain paraffins to branched chain paraffins, sodium aluminum chloride may be used as a catalyst or anhydrous aluminum chloride or sodium fluoride. boron supported on absorbent vehicles such as activated charcoal, natural or activated arils, synthetic gels, etc. The temperature can be in the range of 200 to 300 F and the pressure can range from atmospheric pressure to 300 pounds per square inch. To isomerize olefins, one can use activated clays, bauxite, and activated aluminas as catalysts, and the temperature can range from 5750 to 1000 F.



   In the catalytic refining of hydrocarbons to remove the? gum-forming constituents, sulfur and other impurities, activated alumina, alumina gels, naturally active or activated clays with or without the presence of other metal oxides can be employed as catalysts.



  In this process, the temperature is lower than the active cracking temperature, for example from 400 to 800 F,
For reactions involving hydrogenation, pressures in excess of 300 pounds per square inch will be employed.



  Temperatures above. 700 F can be used with a catalyst consisting of finely powdered nickel, tungsten or molyodene or their oxides and sulphides. Other known hydrogenating catalysts can also be employed.



   For example in certain variations of catalytic cracking and in certain other operations using the present invention, the amount of heat released in the regeneration may be relatively small and the desired operating temperature range from inlet to outlet may be relative. - very large, so that it is possible to cool the stream of spent liquefied catalyst before its introduction into the regenerator and to eliminate the re-entry of the regenerated catalyst from the vertical pipe containing the regenerated catalyst to the regenerator.



   In some cases it may be desirable to heat the recirculated regenerated catalyst to the reaction vessel instead of cooling it.



   In some operations as well, which utilize the present invention, the amount of heat absorbed in the processing phase may be relatively large and the desired operating temperature range from inlet to outlet may be relatively small, ranging from inlet to outlet. so that it is desirable to add to the above-described apparatus equipment not shown to allow recirculation of the catalyst from the spent catalyst riser through an indirect heat exchange device or heat exchanger. another way (to heat the stream) to the reaction vessel.



   Although the catalytic removal phase has been shown

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 seur recovered in primary cyclone 34, in many of these this phase can be deleted *,
For lack of one. better term, the term "fluistatic" has been employed in the claims as a synonym for "hydrostatic II except that it is not limited to liquids. Rais also applies to finely divided solids which in the fluidized state , behave in many ways like a liquid.



     After having described the preferred embodiment of the invention, it should be pointed out that the invention encompasses the other variants and modifications which come within its scope.


    

Claims (1)

R ev e n d i c a t i o n s. 1. A method of continuously circulating finely divided solids through a processing zone, which comprises the features of maintaining a vertical column of such finely divided solids, maintaining a gas of. fluidizing in intimate admixture with these solids along the length of the column, controlling the amount of fluidizing az in admixture with the solids in the column to maintain these solids in a fluidized state and thereby produce a pressure. sion of fluid at the base of the column, to. removing the finely divided solids from the base of the column in a gas stream to the treatment zone, maintaining the finely divided solids in contact with this gas in the processing zone for a fixed period, separating the finely divided solids from the gas and then sending the solids thus separated to the top of the column for the back to the treatment area. 2. A process according to claim 1, wherein the fluidizing gas is introduced at spaced points along the length of the column, to maintain the solids at. the fluidized state. 3. A process according to claims 1 and 2, wherein the finely divided solids form a catalyst for carrying out the treatment in the treatment zone. 4. A process according to any preceding claim wherein the gases to be treated are composed of hydrocarbon vapors. @ 5. A process according to any one of the preceding claims wherein the treatment zone comprises a cracking zone in which hydrocarbon vapors are cracked to form lower boiling point hydrocarbons. . 6. A process according to any preceding claim wherein the finely divided solid material is subjected, following separation, to a regeneration treatment before being returned to the top of the column. 7. A process for continuously treating solids and gases which comprises the features of. maintaining a vertical column of the finely divided solids, maintaining a fluidizing gas intimately mixed with the solids throughout the length of the column, controlling the amount of fluidizing gas. tion maintained in admixture with the solids in the column to maintain these solids in a fluidized state capable of producing a base fluid pressure. <Desc / Clms Page number 14> the column, to evacuate the finely-divided solids from the base of the column) by the fluid pressure produced by this column, in a stream of gas to be treated, passing these gases from the bottom upwards through a processing zone at a rate controlled to allow partial separation of finely divided solids from these gases and thereby forming a relatively dense mixture of gases and solids in the processing zone, a mixture which is maintained in a turbulent state by the bottom-to-top passage of the gases through the treatment zone, the finely divided solids being continuously separated from the gases undergoing treatment and then sent to the top of the column. 8. The method of claim 7, wherein the finely divided solids are continuously separated from the gases undergoing the treatment and are regenerated and returned to the top of the column. 9. The process of claims 7 and 8, wherein the finely divided solids thus separated are discharged to the top of a second column maintained in the fluidized state, and the finely divided solids of the second column are discharged to the top. a second gas stream capable of regenerating these solids, the finely divided solids then being separated from the second gas stream and returned to the top of the first-mentioned column. 10. A process according to claims 7 and 8, wherein the finely divided materials constitute a catalyst for effecting the treatment. 11. The method of claims 7 is: 9, wherein the gases to be treated comprise hydrocarbon vapors. 12. A process according to claims 7,9 and 10, in which the hydrocarbon vapors are subjected to cracking in the treatment zone,