EP2222395A1

EP2222395A1 - Reactor and method for gaseous phase endothermal reaction on a solid catalyst

Info

Publication number: EP2222395A1
Application number: EP08872450A
Authority: EP
Inventors: Gilles Ferschneider; Béatrice Fischer
Original assignee: IFP Energies Nouvelles IFPEN
Current assignee: IFP Energies Nouvelles IFPEN
Priority date: 2007-12-06
Filing date: 2008-12-01
Publication date: 2010-09-01
Also published as: KR20100105572A; US20100252482A1; TW200940171A; SA108290772B1; WO2009101280A1; FR2924624B1; FR2924624A1

Abstract

The invention relates to a reactor for the catalytic reforming or the dehydrogenation of hydrocarbons, having a cylindrical shape along a vertical axis, an upper bottom and a lower bottom including at least two annular areas centred on the vertical axis, said two annular areas consisting of a so-called catalytic area (202) and a so-called exchange area (204). Sealed vertical panels (65) divide the reactor into sectors, said sectors each including at least one exchange section and at least one catalytic section, all exchange sections defining the exchange area and all catalytic sections defining the catalytic area. The invention also relates to a method that uses the reactor of the invention.

Description

Reactor and process for endothermic gas phase reactions on solid catalyst

Field of the invention

The invention relates to a reactor and a process using this reactor for endothermic reactions in the gas phase on a solid catalyst. This reactor is particularly suited to catalytic reforming reactions and hydrocarbon dehydrogenation reactions.

The present invention relates to a reactor for recovering the heat of the combustion gas under pressure and to perform the reactions.

The process utilizes pressurized combustion gas to heat the reactor by indirect heat exchange within the reactor.

Prior art:

It is usual to treat the cuts of heavy gasoline (80 - 18O ⁰ C) comprising mainly hydrocarbons between C6 and C10 from the initial distillation of oil to bring their octane number to a high value for use in an engine of car automobile. The catalytic reforming process makes it possible to perform this operation. This process consists in passing the gasoline cut in the presence of hydrogen over a catalyst comprising precious metals at a high temperature (close to 500 ^° C.). Catalytic reforming reactions consist mainly of dehydrogenating the naphthenes and paraffins present in the feedstock to transform them into aromatics that have a high octane number, and to isomerize the remaining paraffins to also increase the octane number of gasoline. A first undesirable reaction is cracking which produces light hydrocarbons, such as methane, ethane, propane and butane and which reduces the yield of the operation. A second undesirable reaction is the coking of the catalyst, which decreases the activity of the catalyst and forces its periodic regeneration by burning the coke to restore its activity. The cracking is all the more important as the pressure is high. Thus, the yields are better at low pressure. However, the coking is even higher than the partial pressure of hydrogen is low.

The old units operated at high pressure (about 15 to 30 bar), with a high rate of hydrogen recycle, with poor yields, and allowed to operate for about 11 months before it was necessary to regenerate the catalyst.

The units with continuous regeneration of the catalyst make it possible to regenerate the totality of the catalyst in a few days, which allows operation at low pressure (approximately 3 to 5 bars), and therefore higher yields. The catalyst circulates continuously in the reactors, which are then radial type, and is sent to a regeneration section to be regenerated, before being returned to the first reactor. The dehydrogenation reactions are very endothermic, and the reactions stop when the temperature is too low. Current processes generally comprise three or four reactors and as many furnaces in series. Each oven is followed by a reactor. Because of high temperatures, the furnaces have a low yield and it is customary to produce steam to improve the overall efficiency of the furnace. It is also customary to use this steam to drive a turbine driving the recycle compressor and the hydrogen export compressor. In recent years, it is more common to use a variable speed electric motor for compressors, and the use of steam is lower in modern refineries, which for economic reasons favor the use of electricity. As a result, the use of large steam generating furnaces with the associated problems of operation and maintenance is nowadays rather a disadvantage for the process.

Other hydrocarbon dehydrogenation processes such as the dehydrogenation of long paraffins use a process identical to catalytic reforming and are concerned with the same problem. Brief description of the invention

The invention relates to a reactor for catalytic reforming or dehydrogenation of hydrocarbons having a cylindrical shape along a vertical axis, an upper bottom and a lower bottom comprising at least two annular zones centered on the vertical axis, these two zones. annular being an area called catalytic zone and a so-called zone exchange area. Vertical hermetic panels divide the reactor into sectors, said sectors each comprising at least one exchange section and at least one catalytic section, all of said exchange sections forming the exchange zone and all of said catalytic sections forming the catalytic zone. The invention also relates to the process using the reactor according to the invention.

The present invention generally uses for the heating of the reactor, preferably the reforming reactor, pressurized combustion gases which also make it possible to produce electricity for the catalytic reforming unit, and possibly for other units. A single reactor is generally used, with special internals allowing the alternation of heating sections by exchange with the combustion gas and adiabatic catalytic sections, the catalyst being able to circulate by gravity in the reactor. The overall footprint of the unit, the number of equipment and the cost of the reaction section are thus reduced.

If the size of the reactor is too large, in the case of very large capacities, several reactors of this type may be present, preferably in parallel. Each reactor is then generally fed by a dedicated air compressor and a dedicated burner.

Detailed description of the invention

Throughout the text, 1 bar equals 0.1 MPa. The invention relates to a reactor for carrying out an endothermic gas phase reaction having a cylindrical shape along a vertical axis and comprising: at least two annular zones centered on the vertical axis: a catalytic zone and an exchange area

vertical hermetic panels (65) located along the radii of the cylindrical reactor divide the reactor into sectors, said sectors each comprising at least one exchange section (61) and at least one catalytic section (62), all of said exchange sections forming the exchange zone (204) and all of said catalytic sections forming the catalytic zone (202).

In the context of the invention, the first sector is defined as the sector in which the reaction mixture is fed to the reactor. The other sectors are named second sector, third sector up to the last sector, respecting the circulation order of the reaction mixture in the reactor. For example, in the case of 4 sectors, the first sector is that in which the reaction mixture feed to the reactor takes place. The reaction mixture then circulates successively in this first sector then in the second sector then in the third sector and then in the last sector before being discharged out of the reactor.

According to a preferred embodiment, the catalytic zone and the exchange zone, follow one another from the edge to the center of the reactor.

According to another preferred embodiment, at least four annular zones centered on the vertical axis follow one another from the edge to the center of the reactor, a first zone (201) called a feed zone, a second zone (202) called a catalytic zone. a third zone (203) called the collection zone and a fourth zone (204) called the exchange zone. According to this variant, the vertical hermetic panels (65) dividing the reactor into sectors are fixed along a central cylindrical zone (205). Generally, the sectors each comprise an exchange section (61), a catalytic section (62), a feed section (161) and a collection section (162), all of said exchange sections forming the exchange zone (204), all of said catalytic sections forming the catalytic zone (202), all of said feed sections forming the feed zone (201) and all of said collection sectors forming the collection zone (203). Generally, the reactor comprises an upper bottom and a lower bottom. At least one tubing (163) per section generally passes through the upper bottom of the reactor to supply catalytic catalyst sections and at least one tubing (263) per section passes through the lower bottom of the reactor to discharge the catalyst from the catalytic sections. Generally, a supply pipe (17) passing through the upper bottom of the reactor makes it possible to feed a sector, called the first sector, into a reaction mixture, an evacuation pipe (18) passing through the upper bottom of the reactor makes it possible to evacuate the last sector of the reaction mixture reactor. A conduit (67) connecting the collection area of the last sector to the conduit (18) for discharging the reaction mixture is generally present. According to this same variant, an inlet duct (6) passing through the lower bottom of the reactor is connected to ducts (70) leading to tubular chambers (71). The tubular chambers distribute flue gas by means of tubular plates (69) through the bottom of the reactor into each exchange section. Tubular chambers (72) make it possible to collect the combustion gas at the top of each exchange section, then ducts (73) provided with expansion bellows (74) make it possible to evacuate the combustion gas towards the outlet duct ( 7) which passes through the upper bottom of the reactor.

Each exchange section is generally made of tubular heat exchangers or plate heat exchangers. Each exchange section has either an identical surface or the exchange surface increases from the first to the last exchange section.

Each catalytic section is generally formed by two concentric metal grids, preferably of the "Johnson grids" type. All catalytic sections generally have the same size or the size of the catalytic sections increases from the first to the last sector. Vertical hermetic panels (65) generally divide the reactor into 3, 4, 6 or 8 sectors, preferably 4 or 6 sectors.

According to a very preferred embodiment, a conduit (64) connects the collection section of each sector, except for the last sector, to the exchange section of the next sector.

The invention also relates to the method of carrying out a catalytic reforming or dehydrogenation reaction of hydrocarbons in a reactor according to the invention.

The invention also relates to the method for carrying out an endothermic gas-phase reaction of catalytic reforming or dehydrogenation of hydrocarbons on a solid catalyst in a reactor according to the most preferred embodiment in which the reaction mixture enters the reactor. via the conduit (17), flows up and down in the first exchange section (61). Said reaction mixture then passes under the first catalytic section (62) between the catalyst descent pipes (263), then passes radially through the first catalytic section (62), passing from the supply zone (201) to the collection zone. (203) of the reactor, passes to the exchange section of the second sector by the pipe (64). Finally, the reaction mixture circulates successively and alternately in the following exchange sections and the following catalytic sections.

The catalyst generally flows up and down at the same rate in all catalytic sections. The catalyst can also flow up and down at a higher and higher rate from the first to the last catalytic section.

The invention also relates to the method wherein the pressurized combustion gas provides heating of the reaction mixture by indirect heat exchange. According to a first production variant of the combustion gas, the combustion gas supplying the reactor (60) via the pipe (6) comes from the heating of air under atmospheric pressure flowing via the line (1) to an air compressor ( 2) then via the line (3) to a combustion chamber (4) in which the burning of a fuel gas circulating via (5) can carry the combustion gas to a temperature between 600 ⁰ C and 800 ° C and preferably between 650 ⁰ C and 750 ⁰ C.

According to a second variant of production of the combustion gas, the combustion gas supplied to the reactor (60) via the pipe (6) comes from the heating of air under atmospheric pressure flowing via line (1) to an air compressor ( 2) then via the line (3) to a combustion chamber (4) in which the burning of a fuel gas circulating via 5 is used to heat the combustion air, which then passes through an expansion turbine (12) which is on the same shaft as the air compressor and which provides the power required for compression, the combustion gas leaving the expansion turbine (12) is at a pressure between 0.2 and 0.45 MPa, and at a temperature between 600 and 800 ° C, and preferably between 650 and 750 ° C.

According to each of the two variants of production of the combustion gas, the combustion gas leaving the reactor via the pipe 7 can be heated in a combustion chamber (8) before being sent into an expansion turbine (10) to produce electricity.

Description of the figures:

Figure 1 depicts one of the ways of supplying heat to the reactor. Atmospheric air is supplied via line (1) to the air compressor (2). The air is compressed at a pressure of about 4 bars absolute (0.4 MPa) and is then sent via line (3) into a combustion chamber (4). A combustible gas is fed via line (5) to be burned in the combustion chamber (4). The depleted air heated by combustion at a temperature of 700 ^° C. is sent via line (6) into the reactor (60). The reaction mixture enters via line (17) and exits via line (18). The combustion gas is cooled by exchange with the reaction mixture undergoing an endothermic catalytic reforming reaction.

At the outlet of the reactor, the cooled gas is sent via the line (7) to a second combustion chamber (8), where it is heated by combustion of the fuel gas supplied via the line (9). At the outlet of the combustion chamber, the hot gas is sent at a temperature of 75O ⁰ C in an expansion turbine (10) which drives an alternator (11) to produce electricity.

Figure 2 depicts an alternative way of supplying heat to the reactor (60). Atmospheric air is supplied via line (1) to the air compressor (2). The compressed air at a pressure of about 20 bar is then sent via line (3) into the combustion chamber (4). A combustible gas is fed via line (5) to be burned in the combustion chamber (4). The depleted air and heated by combustion at a temperature of 1300 ⁰ C is sent into an expansion turbine (12) which drives the air compressor (2). The gas at the outlet of the turbine is around 3 bars and at a temperature of 700 ^° C. It is sent via line (6) into the reactor (60).

The reaction mixture enters via line (17) and exits via line (18). The combustion gas is cooled by exchange with the reaction mixture undergoing an endothermic catalytic reforming reaction. At the outlet of the reactor, the cooled gas is sent via the line (7) to a second combustion chamber (8), where it is heated by combustion of the fuel gas supplied via the line (9). At the outlet of the combustion chamber, the hot gas is sent at a temperature of 75O ⁰ C in an expansion turbine (10) which drives an alternator (11) to produce electricity.

FIG. 3 describes a variant of FIG. 1 in which heat is recovered from the hot gases flowing via the line (40) at the outlet of the turbine (10). The heat exchanger (41) makes it possible to recover heat either: -by steam production, which can be used in the refinery or to produce electricity,

or by heating a heat transfer fluid (hot oil), which can be used, for example, to reboil the columns of the process. The effluent gas from the exchanger (41) flows via the line (42).

This variant is of course also possible in the same way in the case of Figure 2 (not shown).

FIG. 4 represents the reaction section of a catalytic reforming according to the invention.

The combustion gas enters via the line (6) and exits via the line (7) of the reactor (60).

The charge arrives via the line (14) to the charge pump (15). The discharge charge of the pump is sent via line (16) to the heat exchanger (19), which is preferably of the Packinox type.

The recycling gas circulating via the line (26) is also sent to this exchanger (19), to be mixed with the charge circulating via the line (16) in the exchanger and heated to a temperature of 44O ⁰ C by exchange with the reaction mixture leaving the reactor (60) via the line (18). At the outlet of the heat exchanger (19), the reaction mixture is sent into the reactor (60) via the line (17). The reaction mixture leaving the reactor via the line (18) is around 490 ° C. and is sent to the top of the heat exchanger (19), where it is cooled to around 100 ^° C. At the exit of the heat exchanger (19), the effluent is sent via the line (20) to a heat exchanger (21), where it is cooled by heat exchange with air or cooling water. At the outlet of the exchanger (21), the cooled and partially condensed effluent is sent via line (22) to the separator tank (23). The liquid from the flask is withdrawn via line (28) to a stabilizing section. The gaseous phase of the separator tank (24), consisting mainly of hydrogen, is used in part to constitute a gaseous recycle, compressed by the compressor (25) and then circulating via the line (26), the remainder being sent to a section of purification via the line (27). Figures 5, 6, 7 and 8 show a preferred version of the reactor in different sections.

Figure 5 schematically shows the reactor (60) in section and seen from the front. Four annular zones centered on the vertical axis follow each other from the edge towards the center of the reactor, a first zone (visible in FIG. 6 number 201) called the feed zone, a second zone (visible in FIG. catalytic zone, a third zone (visible in Figure 6 number 203) called collection zone and a fourth zone (visible in Figure 6 number 204) said exchange zone.

Vertical hermetic panels (visible in FIG. 6 number (65)) are fixed on the central cylindrical zone (visible in FIG. 6, number 205) and divide the reactor into sectors.

Each sector has an exchange section (61) and a catalytic section (62). All exchange sections form the exchange zone

(204) and all of the catalytic sections form the catalytic zone (202).

Each sector has a feed section (161) and a pickup section (162). The set of feed sections forms the feed zone (201) and all of the collection sections form the collection zone (203).

The flue gas flows up and down the reactor. The combustion gas is fed from the bottom of the reactor via the inlet duct (6) and is distributed in each exchange section via the ducts (70) and via the tubular chambers (71) before being distributed by tubular plates (69) in tubes (99). At the outlet of the tubes, the combustion gas is collected at the top of the reactor in tubular chambers (72) and then sent via the conduits (73) provided with expansion bellows (74) to the outlet duct (7).

The reaction mixture successively traverses all sectors. The reaction mixture enters through the conduit (17) and at the outlet of the collection section of the last sector, it is collected by the conduit (visible in Figure 6 number 67) and then leaves the reactor via the conduit (18). The circulation of the reaction mixture, comprising hydrogen and hydrocarbons, is represented by the arrows.

The inlet pressure of the reactor is close to 4 bars. The reaction mixture enters the exchange zone of the first sector through the inlet (66) (see arrow 101). In this first sector, the reaction mixture heats down (arrow 102) against the current of the combustion gas and exits through the outlet (75) of the first exchange section. The gas passes below the catalytic section 62 (arrow 103), between the descent tubes of the catalyst (263), goes up along the ferrule, and passes through the catalytic section (62) (arrows 104). The reaction mixture reacts and cools very quickly on the catalyst because the naphthenes present in the feed react very quickly and very endothermically.

The temperature is generally less than 400 ^° C. at the outlet of the first catalyst section. The reaction mixture is then removed from the first section at the top of the reactor and sent to the second section via a pipe (visible in FIG. 6, number (64)). The reaction mixture is reheated in the exchange section of the second sector and then cooled by reacting in the catalytic section of the second sector.

As the reactions progress, there are fewer and fewer naphthenes, the paraffins are slower to react, and the exothermic cracking partly compensates for the endothermicity of the other reactions. The output temperature profile thus input of the reaction mixture in the successive sectors is ascending, which is considered favorable for the yields. At the outlet of the last sector, the reaction mixture is collected by the conduit (visible in Figure 6 number 67) and sent to the outlet duct (18).

Figure 6 shows the reactor seen from above and in section. Four annular zones centered on the vertical axis follow each other from the edge to the center of the reactor: the feed zone (201), the catalytic zone (202), the collection zone (203) and the exchange zone (204). ).

Vertical hermetic panels (65) are attached to the central cylindrical zone (205) and divide the reactor into 8 sectors. The conduits (64) allow the passage from one sector to another. The reaction mixture enters the first exchange section through the inlet (66). At the outlet of the last sector, the reaction mixture is collected by the conduit (67).

FIG. 7 shows a sector of the reactor seen from the center of the reactor, with the exchange section (61) in the foreground, the tube plate (69), and the catalytic section (62) in the background, with the downcomers catalyst (163) and (263) and the closure plates (68). FIG. 8 represents the same sector seen from the ferrule, with the exchange section (61) in the background, the catalytic section (62) in the foreground, the exit of the exchange section (75), the passage ( 64) from one sector to another and a closure plate (68).

Example

The configuration of the reactor shown in FIGS. 5 to 8 is implemented in this example.

A catalytic reforming unit treating 60 tons per hour of charge is considered, with 35 tons of catalyst.

The filler is a 90-170 ^° C. section, with a paraffin content of 60% by volume, 25% naphthenes and 15% volume aromatics.

The molar ratio of pure hydrogen to the charge is 2.5

The target octane is 102. The entire catalyst is regenerated continuously in 2.5 days.

To provide the heat of reaction, about 75.24 million kJ / h (18 million kcal / h), we compress 330 tons of air at 4 bar absolute. The centrifugal air compressor has a polytropic efficiency of 80% and consumes 16.7 MW. The outlet temperature of the compressor is 192 ^° C. 4160 kg / h of natural gas are burned in the first combustion chamber at 15 ^° C., with a lower heating value of 46439.8 kJ / kg (1110 kcal / kg). ). The combustion chamber outlet temperature of 700 ⁰ C. The combustion gas passes via line (6) to about 700 ⁰ C. The inlet and outlet temperatures on the catalytic reforming side in the different sectors are as follows:

Reaction mixture

The reaction mixture reaches 450 ^c C in the reactor, from the exchanger effluent load Packinox. It is heated by exchange with the hot fumes of the first sector and reaches 486 ° C in the catalyst of the first sector, it is then sent to the second sector, where it is heated before being fed to the second sector. 8 sectors are assumed in this example: catalytic section 1: entry into the catalyst at 486 ° C., exit at 396 ° C. catalytic section 2: entry into the catalyst at 441 ^° C., exit at 419 ^° C. catalytic section 3: 46 ° inlet ⁰ C, output 437 ° C catalytic section 4: inlet 475 ⁰ C, outlet 451 ⁰ C catalytic section 5: inlet 487 ° C, outlet 463 ° C catalytic section 6: inlet 497 ⁰ C, outlet 475 ° C catalytic section 7: inlet 507 ⁰ C, outlet 487 ° C catalytic section 8: inlet 517 ° C, outlet 501 ⁰ C (at 4.8 bar absolute)

flue gas

^1st exchange section: 700 ° C input, 471 ⁰ C output 2nd exchange section: 700 ⁰ C input, 422 ⁰ C output 3rd exchange section: 700 ⁰ C input, 442 ° C output

4th exchange section: 700 ° C input, 460 ° C output 5th exchange section: 700 ⁰ C input, 472 ° C output 6th exchange section: 700 ⁰ C input, 483 ° C output 7th exchange section : input 700 ⁰ C, output 494 ⁰ C 8th exchange section: input 700 ⁰ C, output 505 ⁰ C

The flue gas exited the reactor at 469 ° C, after yielding 88.198 million KJ / h (21.1 MM Kcal / h) to the reaction mixture. The effluent combustion gas is sent to a second combustion chamber where 2560 kg / h of combustible gases are burned to reach 760 ^° C. at a pressure of 3.4 bar absolute at the inlet of an expansion turbine. This turbine has a polytropic efficiency of 85% and provides about 26 MW of electrical power that drives the air compressor and provides enough electricity for catalytic reforming and pretreatment units.

At the turbine outlet, the gaseous effluent is at a temperature of 526 ^° C., which makes it possible either to produce more electricity by generating steam or to heat a heat transfer fluid which makes it possible to reboil the columns of the process (the stripping column of pretreatment and stabilization of reforming).

In this example, there is 48.07 million kJ / h (11.5 MM kcal / h) available between 526 ° C and 400 ⁰ C, which is more than enough for the two columns.

An exchange area of approximately 4000 m ² is necessary, ie 8 times 500 m ² . This corresponds to 8 times 350 tubes 30 mm in diameter and 15 m long. The example is given with tubular exchangers to simplify the calculations, but it is possible, without departing from the scope of the invention, to use other types of exchangers, for example Packinox type welded plate heat exchangers, which should allow a much better compactness.

The tubes are installed in triangular pitch pitch P = 38 mm. With this step, it takes a section of 0.00125 m2 (0.866 x P ² ) to accommodate a tube, so about 3.5 m2 to house the 2800 tubes.

Leaving an access of 0.8 m diameter in the center and increasing the area by 15% to take into account the sectioning, it requires a surface of 0.5 + 3.5 x 1, 15 = 4.5 m2 for the entire exchange zone, a diameter of 2.4 m.

The catalyst is installed in an annular zone of internal diameter 3.2 m and a height of about 14 m. We have 35 tons of catalyst, about 50 m3, so 3.6 m2 of catalytic zone (50/14). The outer diameter of the annular catalytic zone is therefore 3.85 m.

Each sector thus comprises from the outer shell: -an empty section (about 60 cm)

a section filled with catalyst between two grids Johnson or equivalent (approximately 65 cm)

-a free section (about 40 cm)

an exchange section (about 80 cm) filled with vertical tubes 30 mm in diameter

-a central free section (about 40 cm radius)

In order to install the exchange tubes and the catalyst as explained above, a ferrule of 5.7 m inside diameter and about 16.5 m in height is required.

The coke produced is very low in the first sector, and increasingly important sector in sector, to be the highest in the last (8% coke if the catalyst circulates in 2.5 days in this sector). One solution is to circulate the catalyst everywhere at the same speed, to mix the catalyst at the outlet of the reactor to send it to the regenerator and to regenerate it as a mixture, the average coke content is then only about 4%, and allows regeneration without risk.

However, the catalyst of the first sectors is regenerated before it is necessary, and it is probably preferable to size the catalyst descent devices so that the catalyst of the first sectors falls more slowly, and the catalyst of the last descends more quickly.

Claims

claims

A reactor for carrying out an endothermic gas phase reaction having a cylindrical shape along a vertical axis and comprising:

at least two annular zones centered on the vertical axis: a catalytic zone and an exchange zone of the vertical hermetic panels (65) located along the radii of the cylindrical reactor which divide the reactor into sectors, said sectors each comprising at least one at least one exchange section (61) and at least one catalytic section (62), all of said exchange sections forming the exchange zone (204) and all of said catalytic sections forming the catalytic zone (202) .

2- reactor according to claim 1 wherein the catalytic zone and the exchange zone follow one another from the edge to the center of the reactor.

3- reactor according to one of claims 1 or 2 wherein at least four annular zones centered on the vertical axis follow one another from the edge to the center of the reactor, a first zone (201) said feed zone, a second zone (202) said catalytic zone, a third zone (203) called the collection zone and a fourth zone (204) called the exchange zone.

4- reactor according to one of claims 1 to 3 wherein the vertical hermetic panels (65) are fixed along a central cylindrical zone (205), said sectors each comprise an exchange section (61), a section catalytic converter (62), a feed section (161) and a collection section (162), all of said exchange sections forming the exchange zone (204), all of said catalytic sections forming the catalytic zone (202), all of said feed sections forming the feed zone (201) and all of said collection sections forming the collection zone (203). 5. Reactor according to one of claims 1 to 4 wherein at least one tubing (163) per sector passes through the upper bottom of the reactor to feed the catalytic catalyst sections and at least one tubing (263) by sector crosses the bottom bottom reactor to remove the catalyst from the catalytic sections.

Reactor according to one of claims 1 to 5 comprising an upper bottom and a lower bottom and wherein:

a supply duct (17) passing through the upper bottom of the reactor makes it possible to feed a sector, called first sector, into a reaction mixture; an evacuation duct (18) passing through the upper bottom of the reactor makes it possible to evacuate the mixture; reaction of the last sector of the reactor

a duct (67) connects the collection zone of the last sector to the duct (18) making it possible to evacuate the reaction mixture.

7- Reactor according to one of claims 1 to 6 wherein:

- an inlet duct (6) passing through the lower bottom of the reactor is connected to ducts (70) leading to tubular chambers (71), said tubular chambers distributing combustion gas by means of tubular plates (69) by means of bottom of the reactor and in each exchange section

tubular chambers (72) make it possible to collect the combustion gas at the top of each exchange section, then ducts (73) provided with expansion bellows (74) make it possible to evacuate the combustion gas towards the outlet duct (7) which passes through the upper bottom of the reactor.

8- reactor according to one of claims 1 to 7 wherein each catalytic section is formed by two concentric metal grids.

9- reactor according to one of claims 1 to 8 wherein each exchange section consists of tubular exchangers.

10- reactor according to one of claims 1 to 8 wherein each exchange section consists of plate heat exchangers. 11- Reactor according to one of claims 1 to 10 wherein each exchange section has an identical surface.

12- reactor according to one of claims 1 to 10 wherein the exchange surface increases from the first to the last exchange section.

13- reactor according to one of claims 1 to 12 wherein all the catalytic sections have the same dimension.

14- Reactor according to one of claims 1 to 12 wherein the dimension of the catalytic sections increases from the first to the last catalytic section.

15- reactor according to one of claims 3 to 14 wherein a conduit (64) connects the collection section of each sector, except the last sector, to the exchange section of the next sector.

16. Reactor according to one of claims 1 to 15 wherein the vertical hermetic panels (65) divide the reactor into 3, 4, 6 or 8 sectors.

17. A process for carrying out a catalytic reforming or dehydrogenation reaction of hydrocarbons in a reactor according to one of claims 1 to 16.

18- A method of carrying out a catalytic reforming or dehydrogenation reaction of hydrocarbons in a reactor according to claim 15 wherein the reaction mixture enters the reactor via the conduit (17), flows up and down in the reactor; first exchange section (61) passes under the first catalytic section (62) between the catalyst descent pipes (263), then radially crosses the first catalytic section (62) passing from the supply zone (201) at the collection zone (203) of the reactor, go to the exchange section of the second sector by the pipe (64) and then circulates successively and alternately in the following exchange sections and the following catalytic sections.

19- Method according to one of claims 17 to 18 wherein the catalyst flows from top to bottom at the same speed in all the catalytic sections.

20- Method according to one of claims 17 to 18 wherein the catalyst flows from top to bottom at a higher and higher rate of the first to the last catalytic section.

21. A method according to one of claims 17 to 20 wherein the combustion gas under pressure provides heating of the reaction mixture by indirect heat exchange.

22- The method of claim 21 wherein the combustion gas supplying the reactor (60) via the conduit (6) comes from heating air under atmospheric pressure flowing via a line (1) to an air compressor (2) then via a line (3) to a combustion chamber (4) in which the burning of a combustible gas circulating via a line (5) makes it possible to bring the combustion gas to a temperature of between 600 ^° C. and 800 ^° C. .

23- The method of claim 21 wherein the combustion gas supplying the reactor (60) via the conduit (6) comes from heating air under atmospheric pressure flowing via a line (1) to an air compressor (2) then via a line (3) to a combustion chamber (4) in which the burning of a fuel gas circulating via a line (5) is used to heat the combustion air which then passes through an expansion turbine (12). ) which is on the same shaft as the air compressor and provides the power required for compression, the combustion gas exiting the expansion turbine (12) is at a pressure between 0.2 and 0.45 MPa, and at a temperature of between 600 and 800 ^° C. 24- A method according to one of claims 22 to 23 wherein the combustion gas exiting the reactor via the conduit 7 is heated in a combustion chamber (8) before being sent into an expansion turbine (10) to produce electricity.