JPS585959B2 - Multistage catalytic reforming method using different types of catalyst particles flowing down by gravity - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention catalytically converts a hydrocarbon reactant stream in a multistage reaction system in which the reactant stream flows in series through multiple reaction zones and catalyst particles move through each reaction zone by gravity flow. Regarding improved technology for

In particular, the technology is applicable to applications in gas phase systems where the conversion reaction is primarily endothermic and the hydrocarbon reactant flow is cocurrent and laterally radial with respect to the downward movement of the catalyst particles.

Generally, multi-stage reaction systems adopt one of the following two methods.

(1) Side-by-side configuration where the reactant stream or mixture flows in series from one reaction zone to the next, with intermediate heating between the reaction zones.
ion), and (2) stacked designs in which the single or more reaction chambers contain multiple catalyst contacting stages.

In the case where the conversion reaction is carried out in the gas phase and the catalyst particles are moved by gravity flow, and the reaction system exists in a horizontal arrangement, two or more catalyst contact zones are stacked. It is particularly intended for use in processes where one or more additional reaction zones are arranged in a stacked side-by-side relationship.

In this technique, catalyst particles are extracted from the bottom of one reaction zone, and new or regenerated catalyst is introduced into the top of a second reaction zone.

The technology also applies to reaction systems in which the catalyst is arranged as an annular bed and the flow of the reactant stream in series from one zone to the next is perpendicular to or radially transverse to the movement of the catalyst stream. It is intended to be applied.

Generally, radial flow reaction systems consist of tubular sections having different nominal cross-sectional areas and arranged vertically and concentrically to form reaction vessels.

The system has a nominal internal cross-sectional area smaller than the reaction chamber.
It includes a reaction chamber that includes a concentrically arranged catalyst retaining network and a porous central tube having a nominal internal cross-sectional area smaller than the catalyst retaining network.

The reactant stream is introduced in the gas phase into the annular space created between the inner wall of the chamber and the outer surface of the catalyst holding network.

The latter together with the outer surface of the porous central tube forms an annular catalyst retention zone.

The vaporous reactant stream flows laterally and radially through the network and catalyst zone into the central tube and out of the reaction chamber.

Although the tubular array of various reactant elements may take any suitable shape, such as triangular, square, rectangular or diamond-shaped, it is advantageous from a manufacturing and technical point of view to use elements of substantially circular cross-section. It is.

For multi-stack reactor systems with gravity-flowing catalyst particles to which the present invention is particularly applicable, U.S. Pat.
No. 06,536.

The movement of the gravity-flowing catalyst particles from one reaction zone to the next, the introduction of fresh catalyst particles and the withdrawal of spent catalyst particles is accomplished using a plurality of catalyst transfer conduits.

The deactivated catalyst particles are extracted from the final reaction zone and transferred to the regeneration tower, where they are moved downward by gravity flow.

The concept of the invention encompasses processes having two separate reactor systems, each system containing from one to three separate reaction zones, and each system being associated with a separate regeneration column.

Each system includes a catalyst composition that has activity and stability properties that differ from the compositions of other systems.

In particular, the process according to the invention is intended for application in the catalytic reforming of hydrocarbon feedstocks for the production of high octane liquid products in high yields.

Accordingly, one embodiment of the invention includes the following series of steps:
A process for catalytically reforming hydrocarbon feedstocks is directed.

(a) reacting the bulk feedstock with hydrogen in contact with a first catalyst composition disposed in a first reactor system in which the catalyst particles descend by gravity flow; (b) the catalyst particles descend by gravity flow; said first reactor system effluent is further reacted in contact with a second catalyst composition disposed in a second reactor system descending by said second catalyst composition such that said second catalyst composition (c) at least periodically withdrawing deactivated catalyst particles from said first reactor system and in which the catalyst particles descend by gravity flow; (d) at least periodically withdrawing deactivated catalyst particles from the second reactor system, and introducing the withdrawn catalyst particles into a second regeneration column where the catalyst particles descend by gravity flow. (e) regenerating said first and second catalyst particles in said first and second regeneration towers under contact with air, halogen and water vapor, and drying said regenerated catalyst particles; f) withdrawing dried regenerated catalyst particles from said first regeneration tower and at least periodically introducing said regenerated first catalyst composition into said first reactor system; and (g) drying from said second regeneration tower. The regenerated catalyst particles are extracted and the regenerated second catalyst composition is introduced into the second reactor system at least periodically.

In more particular embodiments, the first and second catalyst compositions each contain at least one Group I noble metal component and a halogen component combined with a refractory inorganic oxide and have activity and stability properties. The difference is caused by different noble metal concentrations.

In still other specific embodiments, the first and second catalyst compositions each contain a Group I noble metal component and at least one catalytic metal modifier;
Differences in activity and stability properties result from different catalyst modifications.

The present invention is primarily intended for use in reactor systems where the main reaction is endothermic and takes place in the gas phase.

The following explanation specifically applies to naphtha boiling point range distillates. The present invention is not limited to this, although the catalytic reforming has been carried out for several minutes.

Like many other processes, catalytic reforming has gone through several stages of development and is now a system in which the catalyst bed is in the form of a tube descending through one or more reactors. It's coming.

Typically, the catalyst has a nominal diameter in the range of 0.8 to 4.0 mm in order to provide free-flowing properties for the descending cylinders of catalyst without bridging or agglomeration within the entire reactor system. It is used in a spherical shape.

In multi-stage systems, the reaction chambers are generally arranged in vertical stacks, and a plurality (usually about 6 to about 16) of relatively small diameter conduits transport catalyst particles from one reaction zone to the next lower reaction zone. (by gravity flow) and is used to ultimately extract the catalyst particles from the final reaction zone.

The latter is typically transferred to the top of the catalyst regenerator, where it becomes a descending cylinder of catalyst particles, and the regenerated catalyst particles are then transferred to the top of the upper reaction zone of the stack.

It is particularly important that the catalyst particles have a relatively small nominal diameter, preferably 4.0 mm or less, to smooth and promote gravity flow within each reaction vessel and from one zone to the next.

In conversion systems having separate reaction zones in side-by-side relationship, a catalyst transfer vessel (of the type shown in U.S. Pat. No. 3,839,197) transports catalyst particles from the bottom of one zone to the following zone. It is used to move to the top and from the final reaction zone to the top of the regenerator.

Gas phase catalytic reforming of naphtha boiling range hydrocarbons is 371
Conversion conditions are carried out including catalyst bed temperatures ranging from 0.degree. C. to 549.degree.

Other conditions generally include a pressure of 4.4 to 69.0 atmospheres, an hourly liquid hourly space velocity (defined as the amount of fresh feedstock per hour per total catalyst amount), and 1
．． Hydrogen to hydrocarbon molar ratios ranging from 0:1.0 to 10.0:1.0 are included.

As is known to those skilled in the petroleum refining arts, continuous regenerative reforming systems have many advantages over the fixed bed prior art.

Among these, relatively low pressures111 such as 4.4 to 14.6 atm111 and high hourly liquid hourly space velocities11 to
For example, it is capable of efficient operation at 3.0:1.0 to 8.0:1.0-11.

As a result of continuous catalyst regeneration, a constant catalyst bed inlet temperature, for example 510°C to 543°C, can be maintained for a longer period of time.

Furthermore, a corresponding increase in hydrogen production and hydrogen purity in the recycled gas phase from the product separation device also results.

Catalytic reforming reactions include dehydrogenation of naphthenes to aromatics, dehydrocyclization of paraffins to aromatics, hydrocracking of long chain paraffins to low boiling liquids, and some isomerization of paraffins.

These reactions are entirely endothermic and involve a halogen (e.g. chlorine and/or fluorine) and one or more Group I noble metals (e.g. platinum, osmium, iridium,
rhodium, ruthenium, palladium).

Recent studies have shown that even more can be achieved by simultaneously using catalyst modifiers, usually selected from iron, cobalt, copper, nickel, gallium, zinc, germanium, tin, cadmium, rhenium, bismuth and vanadium and mixtures thereof. It has been shown that favorable results can be obtained.

Catalytic reforming generally employs a multi-stage process, with each stage containing a different amount of catalyst, usually expressed in volume percent.

The reactant streams of hydrogen and hydrocarbon feedstock are intermediately heated and flow in series through reaction zones with successive increasing amounts of catalyst.

In a three reaction zone system, typical catalyst loading is
Stage 10.0% to 30.0%, second stage 20.0% to 40.0%, and third stage 40.0% to 60.0.
%.

For systems with four reaction zones, the appropriate catalyst loading is
Stage 5.0% to 15.0%, second stage 15.0% to 25.0%, third stage 25.0% to 35.0% and fourth stage 35.0% to 50.0%. be.

A progressively increasing uneven distribution of the catalyst in the direction of flow of the reactant stream facilitates distribution of the reaction and total reaction heat.

An important aspect of the present invention is the use of heterogeneous reforming catalysts, characterized by having different binding properties of activity and stability.

For purposes of explanation, we will establish some definitions.

"Activity" is normally defined as the level of operating severity required to obtain a given required octane number for a liquid reforming product stream, ie, pentane and heavier hydrocarbons.

For example, to obtain a final product with a lead-free research octane number of 100.0, when all other variables are constant except catalyst bed temperature, a catalyst producing this product at 50 γC would require a temperature of 518 °C. It is more active than other substances.

Similarly, the catalyst bed temperature is kept constant and the hourly liquid hourly space velocity (LH
SV) is adjusted to obtain the target octane number, L
The catalyst that gives the desired results at HSV2.0 is LHS
It is more active than those requiring V1,75.

Catalyst "stability" is defined as the rate of change in activity related to catalyst life measured as cubic meters of feed per kg of catalyst charged into the reaction chamber, m3/#g.

Stability is often expressed in units of temperature increase per unit of catalyst life to maintain a constant target octane number, usually for a liquid product stream, which is commonly expressed in C/m''/kg.

Therefore, a catalyst composition with a deactivation rate of 4.0°C/m'/kg is significantly more stable than one with a deactivation rate of 127°C/m3/kg.

The yield of pentane and heavier products and the purity of hydrogen in the gaseous products are also used to select the catalyst composition for use in the reforming system.

The reforming catalyst composition is unique in that it has dual functionality;
This can be defined in a variety of ways, but most commonly the catalyst exhibits both acidic properties and metal hydrogenation/dehydrogenation functions.

The heterogeneity of the catalysts used in the process techniques of the present invention is achieved primarily by varying the dual-functional properties of the compositions.

As mentioned above, catalyst compositions exhibit different binding properties of activity and stability.

To illustrate, various reforming catalyst compositions were subjected to activity and stability performance tests and rated on a scale of 1 to 10, with 10 indicating the highest activity and highest stability compared to standard catalysts and catalysts to each other. Assume that

According to this conveniently chosen scale, catalyst A has an activity of 5.
and a stability value of 10, and catalyst B has an activity of 10 and a stability value of 5, then both catalysts have different binding properties of activity and stability.

Similarly, if both catalysts have an activity value of 8, one has a stability value of 8, and the second has a stability value of 3, for the purposes of this invention have different binding properties.

As mentioned above, the reforming catalyst includes at least one Group I noble metal component such as platinum, palladium, rhodium, ruthenium, osmium and/or iridium, and an acid-active halogen component, typically chlorine, fluorine or both.

During the manufacturing process, these materials are manufactured using alumina, silica, zirconia,
Combined with a heat-resistant inorganic oxide selected from the group of strontia, magnesia, hafnia and mixtures thereof.

Catalyst modifications of the type mentioned above are often combined with these in order to adjust the activity/stability relationship.

The Group I noble metal component is present in an amount of 0.1% to 2.0% by weight calculated on an elemental basis.

Excellent results are obtained when the catalyst contains 0.3% to 0.9% by weight of Group I noble metal component.

The halogen is bound to the carrier material during the filtration process, which impregnates the carrier with the active metal component.

The amount of halogen, in the case of chlorine, fluorine, or both, calculated on an elemental basis, is such that the final catalyst composition contains 0.1% to 1.5% by weight, most commonly 0.3% to 1.5% by weight.
The content is 2%.

The metal catalyst modification is preferably present in an amount ranging from 0.1% to 5.0% by weight on an elemental basis.

Regardless of the absolute amount or nature of these catalyst modifiers,
The atomic ratio of group II noble metals to modified catalysts in the catalyst is:
Preferably o. i:i. Excellent results are obtained with an atomic ratio of 0.5:1.0 to 1.5:1.0.

In certain circumstances for certain naphtha boiling range enlarged feedstocks, it may be necessary to weaken the acid function of the selected catalyst composition.

This is achieved by adding the alkaline metal component in amounts of 0.01% to 1.5% by weight.

This component is selected from the group of lithium, sodium, potassium, rubidium, cesium, barium, strontium, calcium, magnesium, beryllium and mixtures thereof.

Following preparation and calcination, the reformed catalyst composition is subjected to a substantially water-free reduction in hydrogen.

It is convenient to carry out the reduction in the apparatus as a step combined with the start-up operation, but care must be taken to dry the system to a substantially moisture-free state beforehand.

The catalytic reforming process reduces the reducing composition to 0.05 on an elemental basis.
% to 0.5% by weight of sulfur.

Differences in activity and stability properties can be achieved by changing physical properties, chemical properties, or both.

The former includes apparent bulk specific gravity, pore diameter (nominal) and surface area, generally measured in square meters per catalytic duram.

By varying the chemical composition, the activity and/or stability properties can be varied over a wide range and is therefore preferred.

Looking first at refractory inorganic oxide supports, alumina exhibits different activity and stability compared to those containing approximately 20 wt% silica, even with the same Group I noble metal and halogen concentrations. do.

For simplicity, the following description is limited to reforming catalysts with an all-alumina support and chlorine as the halogen component;
The present invention is not limited thereto.

If both catalyst compositions contain platinum as the Group I metal component, differences in activity and stability properties (A/S properties) can be easily achieved by varying the concentration of platinum.

Thus alumina, 0.9% chlorine and 0.75% by weight
The composition of platinum is alumina, 0.9% chlorine and 0
．． It has different bond A/S characteristics than that of 375% platinum.

Similarly, a platinum/alumina catalyst containing 1.0% by weight chlorine has different A/S characteristics than one containing substantially no chlorine.

On the other hand, the chlorine concentration can also be varied to change the A/S characteristics.

Additionally, one catalyst may contain platinum as the only Group I metal component, and a second catalyst may contain both platinum and iridium.

Binary metal compositions, as well as ternary and quaternary metal compositions, differ from monometallic compositions.

Similarly, a catalyst containing platinum, vanadium and chlorine combined with alumina is different from a similar catalyst without vanadium.
/S characteristics differ.

Platinum/alumina/chlorine catalyst is palladium/alumina/
Shows different characteristics from chlorine catalysts.

If the catalyst composition contains the same Group I component and the same chlorine concentration, differences can be obtained by using the same modification at different concentrations.

Whether or not the calcined, reduced catalyst is subjected to a sulfurization technique prior to use will affect the A/S characteristics, as will different concentrations even though the other components and concentrations are the same.

The particular technique is not important in the method of the invention, but rather the activity and stability properties measured are different.

Briefly, the invention uses two separate reactor systems in which catalyst particles descend by gravity flow through each system.

Each system is connected to its own separate regeneration tower, in which the catalyst particles descend by gravity flow.

Each reactor system contains a catalyst that exhibits different activity and stability characteristics than catalysts located in other reactor systems.

Catalyst particles are withdrawn from each reactor system at least periodically;
Introduced into each regeneration tower.

Regeneration is carried out by contacting the deactivated particles with air, halogen and water vapor, followed by a drying operation in substantially moisture-free air, and the catalyst particles are placed in a separate vessel or in a separate reactor system. The reduction operation is carried out in a separate vessel connected to the

The dried regenerated particles are introduced into the separate reactor system at least periodically.

The precise technique used for catalyst regeneration and reconditioning (halogen reconditioning) is not a critical feature of the present invention and may be any prior art method using a mixture of air, steam, and halogen.

For two reactor systems, each includes at least one reaction zone.

Many arrangements are possible according to the invention.

For example, one system may contain two or three individual reaction zones and a second system may consist of one or two individual reaction zones.

As previously mentioned, the reaction zone generally contains varying amounts of catalyst that increase in the direction of flow of the reactant stream.

Catalytic reforming is entirely endothermic and requires interstage heating.

The exact number of individual reaction zones and catalyst distribution therefore depends primarily on the physical and chemical properties of the new feedstock and the final predictions of the reaction and the distribution of the total reaction heat.

As mentioned above, catalytic reforming involves four major reactions, and the overall result is a temperature drop and an endotherm.

For illustration purposes, the catalyst distribution is 10.0%, 15.0%, 25.
When considering a four-reaction zone system of 0% and 50.0%, the first
In the reaction zone, substantially all naphthenic hydrocarbons are dehydrogenated to aromatics, a highly endothermic reaction.

In the second reaction zone, after the temperature of the first zone effluent is raised by intermediate heating, residual naphthenes are dehydrogenated and the dehydrocyclization of paraffins to aromatics takes place, also endothermic.

The latter is also carried out in the third reaction zone together with the isomerization of normal paraffins to isomerized products.

Some isomerization also occurs in the fourth reaction zone, with hydrogenolysis of long chain paraffins to lower molecular weight, usually liquid paraffins.

The idea of the present invention using two different catalyst compositions further facilitates many of the advantages of the latter when used in conjunction with continuous catalyst regeneration/catalytic reforming where the catalyst particles are moved by gravity flow. It provides a process specifically tailored to large raw material properties and desired results.

To further explain the spirit of the invention and the catalytic reforming process it encompasses, reference is made to the accompanying drawings that illustrate one or more embodiments.

The explanation is provided by a simplified system diagram showing only the main equipment.

They include a two-reaction zone stacked reactor system I, a regeneration tower I with a catalyst desorption hopper 1, a two-reaction zone system I, and a regeneration column I with a catalyst desorption hopper 45. It is a tower■.

Details such as pumps and compressors, heaters and coolers, condensers, heat exchangers and heat recovery circuits, start-up piping, valves and similar equipment have been omitted as they are not important to the understanding of the technology.

For the drawings, stacked reactor system I is shown as having two separate reaction zones 5 and 6, in which gamma alumina, 0.95% by weight combined chlorine and approximately 0.75% by weight % platinum and having a nominal diameter of 1.6 mm.

On a conveniently chosen scale of 1 to 10, this catalyst has an activity value of about 8 and a stability value of about 6.

Reaction zones 64 and 65 of stacked reactor system (1) contain gamma alumina, 0.95% by weight combined chlorine, and 0.95% by weight combined chlorine.
A heterogeneous catalyst containing 375% by weight platinum, nominally 1.6 mm in diameter, and presulfided to a sulfur level of 0.25% by weight is disposed.

This catalyst exhibits an activity level of 4 and a stability level of approximately 9.

Thus, in this example, the fresh feedstock is first contacted with a relatively high activity/low stability composition and then contacted with a relatively low activity/high stability composition.

In some situations, the composition may be reversed, primarily due to feedstock properties and overall reaction zone considerations.

That is, low activity/high stability catalysts are followed by high activity/low stability catalysts.

The bulk feedstock in the naphtha boiling range is mixed with the recycled hydrogen-enriched vapor phase and introduced into the catalyst holding and pre-reduction zone 4 via line 59.

A vessel of this type, in which the catalyst is located in the central part 20 and the feed reactant stream flows through the annulus formed by the cylindrical container 21 and the inner wall of the band 4, is described in US Pat.
It is of the type described in No. 536.

The hydrogen to hydrocarbon molar ratio is approximately 6,0:1. O, the pressure is about 7
．． At 8 atmospheres and based on the total amount of catalyst placed in all four reaction zones 5, 6, 64 and 65, the hourly liquid hourly space velocity is approximately 1.5.

Before entering catalyst retention zone 4, the hydrogen/hydrocarbon mixed feed stream is heated to a level such that the inlet temperature of reaction zone 5 is approximately 510°C.

The reactant stream flows laterally and radially from the annular space between the inner wall of the reaction zone 5 and the catalyst holding network 23, enters and passes through the annular catalyst bed 22, and reaches the porous central tube 24 from which the product stream flows into the conduit. It is extracted by 60.

After passing through a reaction zone intermediate heater (not shown), the reactant stream continues through conduit 60 and is introduced into flow reaction zone 6.

The reactant stream again flows laterally and radially through the annular catalyst bed 25 created by the catalyst retaining network 26 and the porous central tube 27 .

The reaction product stream passes through outlet 28 and tube 29, is heated and introduced into catalyst retention zone 32.

As described in the stacked reactor system (1), the catalyst particles from the regeneration tower (2) enter the inlet section 33 and are preheated and prereduced in the holding section 34 within the cylindrical container 35.

Reaction zone 64 is also formed by porous central tube 38 and catalyst retention network 37 and includes an annular catalyst bed 36 through which the reactant flow flows laterally and radially.

The inlet temperature of the reactant stream is 510°C.

The reaction product stream from reaction zone 64 is withdrawn via tube 61, heated to a temperature of 510° C., and introduced into reaction zone 65.

The reactant flow flows laterally and radially from the outer annulus formed by the catalyst retaining network 40 and the inner wall of the reaction chamber 65 into the annular catalyst bed 39 and into the porous central tube 41 .

The final product stream is withdrawn via outlet 62 and conduit 63 and transferred to a cooler/condenser and separation device (not shown) where it is separated into a normally liquid product and a hydrogen-enriched vapor phase.

A portion of the latter is discharged from the system by pressure control, and the remainder is recycled via line 59 to stack reactor system I.

The effluent conduits 60 and 61 begin at the lowest ends of the porous central tubes 24 and 38 in an industrially designed system.

Although these are shown exiting from the sides of reaction zones 5 and 64, this is merely for convenience and simplicity in the drawing.

Regenerated catalyst particles are periodically transferred through the riser 17 and introduced into the catalyst holding and pre-preparation zone 4 via the inlet section 19 .

From bed 20, the catalyst particles are typically about 6 to about 16 in number.
It is discharged to an annular catalyst bed 22 via a plurality of transfer conduits.

The particles flow by gravity to the annular catalyst bed 25 of the reaction zone 6 through a plurality of other transfer conduits.

Deactivated catalyst particles are removed from the lowermost end of reaction zone 6 via a plurality of outlets 30 and conduits 31.

These particles are of the type shown in US Pat. No. 3,856,662 and are not shown in this figure.

Introduced into a fixed extraction and transfer container.

The extracted catalyst particles are transferred to a desorption hopper 1 via a riser pipe 2.

The desorption hopper 1 serves to separate catalyst fines and dust-like particles, which are removed via conduit 3 to a suitable metal recovery device.

The catalyst particles are withdrawn via an outlet 7 and passed through a plurality of transfer conduits 8.
and flows down to the regeneration tower I.

These deactivated catalyst particles are attached to the annular catalyst formed by the cylindrical catalyst holding network 10 and the combustion product exhaust gas central pipe 11. It is arranged as floor 9.

A mixture of air, water vapor and chlorine-containing compounds is introduced into tube 13
It is mixed with the recycled exhaust gas from the reactor and introduced through conduit 12 into the upper carbon combustion/halogenation section of the regeneration tower (1).

In this part, coke and other carbonaceous materials are removed and
Also, the chloride content of the catalyst composition is adjusted back to its original level.

Substantially dry air is introduced via pipe 14 into the lower part of regeneration column I, the drying section, to remove substantially all residual moisture from the catalyst particles.

The exhaust gas combustion products are removed from the central pipe 11 via a conduit 18.

A portion thereof is separated via pipe 13 and combined with a mixture of water vapor, chlorine-containing compounds and air introduced via pipe 12.

Dilution with exhaust gas in this way is expedient in order to maintain the oxygen level in the carbon combustion section at a maximum of about 2.0% on a molar basis.

The dried regenerated catalyst particles pass through the outlet section 16 to the lowermost end section 1.
5 and transferred to the catalyst holding zone 4 through the riser pipe 17.

Lift loaders of the type found in the prior art
A catalyst extraction and transfer vessel is used for this purpose.

In a similar manner, deactivated and chloride-depleted catalyst particles are withdrawn from the stacked reactor system (1) through a plurality of outlets 42 and conduits 43.

These are transferred through riser 44 to desorption hopper 45 and fines and dust-like materials are removed from conduit 46.

The catalyst particles are removed from the outlet 47 and transferred to a plurality of transfer conduits 4.
The catalyst is introduced into the regeneration tower (1) through 8, and is arranged as an annular catalyst bed 49.

The latter is formed by the exhaust gas central pipe 50 and the catalyst holding network 51.

Air, water vapor and chlorine-containing compounds are mixed with recirculated exhaust gas combustion products from pipe 53 and introduced into the carbon combustion top via pipe 52.

As mentioned for the regeneration column (1), coke and other carbonaceous materials are burned off from the catalyst particles and the chloride content is adjusted to its original level.

A stream of substantially dry air enters the lower drying section by conduit 54.

Gaseous combustion products are removed through the exhaust gas central pipe 50 and conduit 58, and at least a portion thereof is separated via pipe 53 for recirculation to the carbon combustion/halogen conditioning section.

The regenerated and substantially moisture-free reconditioned catalyst is extracted from the lowermost end 55 via the outlet 56 and transferred via the riser 57 to the catalyst holding zone 32 located at the top of the reaction system (1).

[Brief explanation of the drawing]

The drawing is a schematic system diagram showing one embodiment of the present invention.

Claims (1)

[Scope of Claims] 1 (a) Reacting the bulking raw material and hydrogen in contact with a first catalyst composition disposed in a first reaction system in which catalyst particles descend by gravity flow; (b ) further reacting the effluent of said first system in contact with a second catalyst composition disposed in a second reactor system in which the catalyst particles descend by gravity flow, so that said second catalyst composition (C) withdrawing deactivated catalyst particles from the first reactor system at least periodically, the catalyst particles descending by gravity flow; introducing said withdrawn catalyst particles into a first regeneration tower; (d) at least periodically withdrawing deactivated catalyst particles from said second reactor system; (e) regenerating said first and second catalyst particles in said first and second regeneration towers in contact with air, halogen and water vapor, and regenerating said regenerated catalyst particles; (f) extracting the dried regenerated catalyst particles from the first regeneration tower and introducing the regenerated first catalyst composition into the first reactor system at least periodically; and (g) removing the regenerated catalyst particles from the second regeneration column. A method for catalytic reforming of a hydrocarbon feedstock, comprising a series of steps of extracting dried regenerated catalyst particles from a regeneration tower and introducing the regenerated second catalyst composition into the second reactor system at least periodically. . 2. The method of claim 1, wherein the first reactor system comprises a plurality of reaction zones, and the first catalyst composition is transferred by gravity flow from one zone to a subsequent zone. 3. The method of claim 1 or 2, wherein the second reactor system comprises a plurality of reaction zones, and the second catalyst composition is transferred by gravity flow from one zone to a subsequent zone. 4. The first and second catalyst compositions each contain at least one Group III noble metal component and a halogen component combined with a heat-resistant inorganic oxide, and the difference in activity and stability properties leads to different noble metal concentrations. The method according to any one of paragraphs 1 to 3, which is brought about by: 5. The method of any one of clauses 1 to 3, wherein the first and second catalyst compositions each contain a halogen component, and the difference in activity and stability properties is provided by different halogen concentrations. 6 The first and second catalyst compositions are each
Group noble metal component and at least one modified catalytic metal (m
3. A method according to any one of clauses 1 to 3, wherein the catalyst modifications contain different activity and stability properties. 7. The method of claim 1, wherein said first reactor system includes at least two separate reaction zones and said second reactor system comprises a single reaction zone. 8. The method according to item 4 or 6, wherein the Group (1) noble metal component is a platinum component. 9. The method of claim 1, wherein said first and second reactor systems each include two separate reaction zones.