FR3090683A1 - Conversion of petroleum crude oil into a compartmentalized fluidized bed - Google Patents

Abstract

The present invention relates to a device and a method for catalytic cracking in a fluidized bed of a hydrocarbon feedstock, in which: a first hydrocarbon feedstock (2A) and at least a second hydrocarbon feedstock (2B, 2C) are cracked in a first compartment ( 6A) and at least one second compartment (6B, 6C) of a dense fluidized bed reactor (1), respectively, the first hydrocarbon charge (2A) being lighter than the second hydrocarbon charge (2B), and in which the first compartment (6A) is supplied with a fresh and / or regenerated catalyst (4) and the second compartment (6B) is supplied with catalyst (4) by circulation between the first compartment (6A) and the second compartment (6B). Figure 1A to be published

Description

Description

Title of the invention: Conversion of petroleum crude into a compartmentalized fluidized bed

Technical area

The invention relates to the field of refining and petrochemicals and processes and devices for the chemical transformation of petroleum products, in particular petroleum crude oil ("crude oil" according to English terminology) by catalytic cracking in a fluidized bed (“Fluid catalytic cracking” or FCC according to English terminology).

Prior art

FCC is a process conventionally used in refining to convert a heavy feed, characterized by a boiling point close to 340 ° C, often above 380 ° C, into lighter products that can be used as fuels , in particular in gasoline, the first FCC product, characterized by temperatures at the beginning of boiling close to the ambient and by temperatures at the end of boiling of 160 ° C or even 220 ° C depending on whether one speaks of gasoline light or not. The field of operation of the process has expanded in its expenses, with in particular mixtures of heavy products and lighter products (recycled cuts from other processes), but also in its products with in particular the production of propylene (olefin of cut C3) for use in petrochemicals, the other light olefins (ethylene in C2) and butenes (olefins in C4) not generally being used as products for petrochemicals (generally cut C2 is not recovered and cut C4 is oriented towards transformation into petrol via the alkylation processes or MTBE for example). In all these cases, the FCC charge or charges were subjected to physical and / or chemical treatments upstream of the process (distillation separations, pretreatment in a catalytic unit to remove nitrogen, metals, etc.).

In order to make an FCC unit even more flexible, it is advantageous to be able to process, in the same FCC unit, several types of petroleum charges or cuts by widening the range of boiling point thereof and therefore, by limiting the number of operations upstream, and by widening the range of products of interest to light olefins such as ethylene, propylene or butenes or to the aromatics contained in liquid fractions.

Depending on the cut to be treated, an optimal contact time and reaction temperature should be considered. Patents describe FCC units comprising several charge injection points and / or several injection points of the regenerated catalyst. Other patents describe the use of several reactors and / or the use of different catalysts.

US 2018/223193 A1 describes an FCC unit comprising two reactors and a compartmentalized regenerator and connected to the two reactors, each compartment of the regenerator making it possible to regenerate the catalyst of each reactor.

FR 3 060 415 A1 describes a turbulent fluidized bed reactor having a compartmentalization for the catalytic cracking of a single charge.

Summary of the invention

In the context previously described, we observed that the lighter loads crack more difficult than heavy loads. We propose to convert the lighter loads with a longer contact time with the catalyst, optionally with a larger amount of catalyst reduced to the amount of load to be converted.

A first object of the present invention is to provide FCC units making it possible on the one hand to treat a hydrocarbon fraction with a large range of boiling temperature and on the other hand to maximize the production of light olefins with logic to increase the synergy between refining and petrochemicals by reorienting the refining processes and their products towards petrochemicals.

According to a first aspect, the abovementioned object, as well as other advantages, are obtained by a catalytic cracking device in a fluidized bed of a hydrocarbon feed, comprising a dense fluidized bed reactor comprising a first compartment and at at least a second compartment for at least partially cracking a first hydrocarbon charge and at least a second hydrocarbon charge, respectively, in which the first hydrocarbon charge is lighter than the second hydrocarbon charge, and in which the first compartment is adapted to be supplied by a fresh and / or regenerated catalyst and the second compartment is adapted to be supplied with catalyst by circulation between the first compartment and the second compartment.

According to a second aspect, the aforementioned object, as well as other advantages, are obtained by a catalytic cracking process in a fluidized bed of a hydrocarbon charge, comprising: cracking at least partially a first hydrocarbon charge and at at least a second hydrocarbon charge in a first compartment and at least a second compartment of a dense fluidized bed reactor, respectively, in which the first hydrocarbon charge is lighter than the second hydrocarbon charge, and in which the first compartment is powered by a fresh and / or regenerated catalyst and the second compartment is supplied with catalyst by circulation between the first compartment and the second compartment.

According to one or more embodiments, each compartment comprises a dedicated input for supplying said compartment with a predetermined hydrocarbon charge, the first compartment being supplied by the lightest hydrocarbon charge and the following compartments being supplied by hydrocarbon charges of heavier and heavier.

According to one or more embodiments, the first compartment is adapted to allow the catalyst to pass into the second compartment by overflowing over a wall separating the first compartment and the second compartment.

According to one or more embodiments, the last compartment comprises a lower window for removing the at least partially used catalyst from the last compartment.

According to one or more embodiments, an optionally central descending or rising conduit is provided for removing the at least partially used catalyst from the dense fluidized bed reactor, the lower window being connected to said descending or ascending conduit.

According to one or more embodiments, the device further comprises an ascending or descending gas-solid co-current fluidized bed reactor connected to the lower window, for treating an additional charge by means of the at least partially spent catalyst. .

According to one or more embodiments, a stripper connected to the dense fluidized bed reactor is provided for desorbing hydrocarbons adsorbed on the at least partially spent catalyst.

According to one or more embodiments, the dense fluidized bed reactor is directly connected to the stripper.

According to one or more embodiments, a regenerator connected to the stripper is provided for burning the coke formed on the desorbed catalyst.

According to one or more embodiments, a transport conduit is provided for transporting the regenerated catalyst from the regenerator to the dense fluidized bed reactor.

According to one or more embodiments, the operating conditions of the dense fluidized bed reactor are as follows:

- gas surface speed: between 0.2 and 2m / s;

- temperature: between 500 and 800 ° C and preferably less than 750 ° C;

- pressure: between 0.1 and 0.6 MPaa; and

- contact time greater than 1 second.

Embodiments of the method and the device referenced above as well as other characteristics and advantages will appear on reading the description which follows, given for illustration only and not limiting, and with reference to the drawings following.

List of Figures

[Fig.lA]

FIG. IA describes a diagram of an FCC device according to one or more embodiments of the present invention comprising a compartmentalized dense fluidized bed reactor.

[Fig.lB]

Figure IB describes a top view of the FCC device according to Figure 1 A.

[Fig.2]

FIG. 2 describes a diagram of an FCC device according to one or more embodiments of the present invention in which the compartmentalized dense fluidized bed reactor is connected to a stripper and a regenerator.

Description of the embodiments

The invention relates to the field of FCC processes and devices for at least partially converting crude oil (e.g. after a first fractionation) in an FCC type unit, with the aim of optimizing the production of light olefins.

The conversion process and device according to the invention can be defined as a series of steps or reactors / cracking sections intended to convert cuts or all cuts of petroleum crude oil. Based on experimental tests, it turns out that the conversion of light loads (eg naphtha) requires a significantly longer contact time than for heavy loads (eg VGO), the latter being conventionally the loads treated in an FCC reactor. (eg fluidized-bed gas-solid ascending or “riser” fluidized bed reactor according to English terminology). We found that it was possible to implement an FCC device comprising a high contact time zone and a lower contact time zone in order to maximize the production of light olefins, the different cuts being injected into the zone. appropriate contact time based on the contact time required for each cut. This involves, for example, injecting a lighter cut in the highest contact time zone, and a heavier cut in the lowest contact time zone. This implementation, which notably comprises successively treating, in the direction followed by the catalyst (solid particles), first the lighter load in a first compartment allowing a long contact time, then the heavier load in another compartment allowing a short contact time is also relevant because it takes advantage of the fact that the cracking of a light fraction is not very coking while the cracking of a heavy cut is very coking. Thus, at the outlet of the first compartment after having contributed to the cracking of the lighter fraction, the catalyst is still active due to its low coke level; it remains operative to crack the heavier fraction, which produces more coke. Once coked, the catalyst no longer plays its catalytic role; the coked catalyst can then be separated from the effluents so that they do not continue to crack under the thermal effect leading to an overproduction of dry gas (also called “dry gas” according to English terminology; light gas fraction at low value ).

The present invention can be defined as a catalytic cracking device in a fluidized bed of a hydrocarbon feedstock, comprising a dense fluidized bed reactor, said reactor being compartmentalized in order to process a plurality of hydrocarbon feedstocks. Specifically, the reactor comprises a first compartment supplied with fresh and / or regenerated catalyst, and one or more following compartments supplied with catalyst from the first compartment, the first compartment being supplied by the lightest charge and the following compartments being supplied by heavier and heavier loads. The reactor thus makes it possible to treat heavier and heavier loads in dedicated compartments with a circulation of catalyst so that it first contacts the lightest load and lastly the heaviest load. According to one or more embodiments, the number of compartments is between 2 and 10, preferably between 2 and 6.

In the present application, the term “dense fluidized bed” means a gaseous fluidized bed operating in bubbling regime or in turbulent regime.

According to one or more embodiments, the dense fluidized bed reactor is chosen from a bubbling fluidized bed reactor and a turbulent fluidized bed reactor (e.g. contact time greater than 1 second such as several seconds).

In the present application, the term “bubbling fluidized bed” means a gas-solid fluidized bed whose gas speed is between the minimum fluidization speed and the speed of transition to the turbulent regime. These speeds depend on the properties of the solid catalyst (density, size, shape of the grains, etc.). The volume fraction of solid is between a value close to 0.4 and the maximum volume fraction of solid corresponding to a fixed, non-fluidized bed, generally close to 0.5.

In the present application, the term "turbulent fluidized bed" means a gas-solid fluidized bed whose gas speed is between the speed of transition to the turbulent regime and the transport speed. The volume fraction of solid is between a value close to 0.25 and a value close to 0.4.

In the present application, the term "transport speed" corresponds to the speed with which essentially all the solid is entrained by the gas. The transport speed is known to the skilled person. For example, the transport speed can be determined according to the properties of the gas (e.g. viscosity and density), the properties of the particles (e.g. size and density) and the size of the fluidized bed (e.g. diameter and height).

Figure IA and Figure IB describe a diagram of an LCC device according to one or more embodiments of the present invention comprising a dense fluidized bed reactor 1 suitable for: being directly fed by and at least partially cracking a plurality of hydrocarbon feedstocks 2A, 2B and 2C; and produce effluents 3 in the presence of a catalyst 4. In FIGS. 1A and 1B, the solid arrows represent the path of the catalyst (solid) in a dense fluidized bed reactor 1, and the hatched arrows represent the path of the charges and effluents (gas) in said reactor.

With reference to FIG. 1A and to FIG. 1B, the dense fluidized bed reactor 1 is compartmentalized so that said dense fluidized bed reactor 1 can process several hydrocarbon charges 2A, 2B and 2C, each of said charges entering ( eg by a dedicated input 5A, 5B or 5C) in a dedicated compartment 6A, 6B, 6C. According to one or more embodiments, the lightest charge 2A has the longest contact time in the dense fluidized bed reactor 1 and the least light charge 2C has the shortest contact time in the bed reactor dense fluidized 1. According to one or more embodiments, in the case of equivalent flow rates between the lightest load 2A and the other loads 2B and 2C, the lightest load 2A enters a first compartment 6A, the least load slight 2C enters a last compartment 6C, the first compartment 6A being the largest compartment (eg in volume and / or height) and the last compartment 6C being the smallest compartment. In the case of respective different flow rates between loads, the size of the compartments can be chosen to favor a decreasing contact time as the load becomes heavier.

According to one or more embodiments, the fluidized bed reactor 1 is cylindrical and the compartments 6A, 6B, 6C form radial sectors of said reactor. According to one or more embodiments, the radial sectors are identical and the compartments 6A, 6B, 6C differ in that the first compartment 6A comprises a height of catalyst greater than that of the second compartment 6B and so on until the last compartment 6C including the lowest catalyst height. According to one or more embodiments, the radial sectors are different and the angle β of the radial sector of the first compartment 6A is greater than that of the second compartment 6B and so on until the last compartment 6C whose angle of the sector radial is the smallest. According to one or more embodiments, the angle β of the first compartment 6A is at least 20 °, preferably at least 30 ° (eg 40 °), larger than that of the second compartment 6B and so on between the second compartment and the third compartment, up to the last compartment

6C.

Referring to Figure IA and Figure IB, the fresh and / or regenerated catalyst 4 enters the first compartment 6A (e.g. through a dedicated inlet 7). The catalyst of a compartment 6A and 6B other than the last compartment 6C is then sent to a downstream compartment (eg by overflow above a wall 8A-B and 8B-C disposed between two adjacent compartments) and the catalyst to less partially used from the last compartment 6C is removed from the dense fluidized bed reactor 1, for example via a lower window 9 (outlet located at the bottom of the last compartment) or any other means allowing the spent catalyst to be directed (eg via a conduit descending 10 (or rising), optionally central) outside the dense fluidized bed reactor 1. In this example, the first compartment 6A and the last compartment 6C are separated by a wall 8A-C adapted to prevent the catalyst 4 from circulating directly from the first compartment 6A to the last compartment 6C. According to one or more embodiments, the lower window 9 is connected to the central downcomer 10.

According to one or more embodiments, at least one intermediate compartment and / or the last compartment 6C are supplied with fresh or regenerated catalyst. For example, the dense fluidized bed reactor 1 can be adapted to send a fresh or regenerated catalyst to the second compartment 6B and / or the last compartment 6C.

According to one or more embodiments, the lower window 9 is connected to an ascending or descending gas-solid co-current fluidized bed reactor, for example via the descending conduit 10. For example, the partially used catalyst leaving of the dense fluidized bed reactor 1 can be used in a riser or downer to at least partially crack an additional hydrocarbon charge, such as a charge heavier than the charges of the fluidized bed reactor 1. The spent catalyst can then be directed towards a stripper and then a regenerator (eg by means of conduits), as defined below with reference to FIG. 2.

According to one or more embodiments, the upper part of the dense fluidized bed reactor 1 located above the compartments 6A, 6B, 6C allows the separation of the gas phase and the catalyst (solid), the latter being reintroduced in the fluidized compartments. According to one or more embodiments, the separation of the gaseous effluents and of the catalyst particles is improved by one or more stages of cyclones, the return legs of which supply the fluidized bed of each compartment with catalyst, or only in certain compartments.

According to one or more embodiments, the effluents 3 follow the same upward path from their respective compartment towards the outside of the dense fluidized bed reactor 1, for example via at least one upper window 11 opening onto a central rising conduit 12. According to one or more embodiments, the effluents 3 are directed to a fractionation column (not shown).

Referring to Figure 2, the at least partially spent catalyst leaving the dense fluidized bed reactor 1, via the central downcomer 10 (eg by gravity), enters a stripper 13 where hydrocarbons adsorbed on the catalyst are stripped (eg hydrocarbons are desorbed or expelled from the interstitial space). The stripper 13 is supplied with a stripping gas (not shown), the stripping gas being preferably devoid of hydrocarbons and preferably comprising coming water vapor, counter-current to the catalyst. According to one or more embodiments, the dense fluidized bed reactor 1 is directly connected to the stripper 13.

Referring to Figure 2, the desorbed catalyst is oriented via an outlet conduit 14 (downflow) and then via a lift 16 (solid in upward flow, transport gas not shown, preferably water vapor ) to regenerator 15 where coke formed on the various catalysts is burned. A transport duct 17 is also provided for sending the regenerated catalyst from the regenerator 15 to the dedicated inlet 7 of the dense fluidized bed reactor 1.

In the present application, the terms "light cut", "couple more / less light than", "heavy cut" and "cut more / less heavy than" mean a fraction of a crude oil whose point of final boil is higher / lower than another fraction of the crude oil.

According to one or more embodiments, the lightest hydrocarbon charge (eg the first charge 2A) that can be sent to the first compartment 6A is a section whose initial boiling point is between 20 and 50 ° C. and a final boiling point of between 70 to 350 ° C, preferably between 70 and 250 ° C, very preferably between 70 to 220 ° C.

According to one or more embodiments, an intermediate hydrocarbon charge (eg the second charge 2B) which can be sent into the intermediate compartment or compartments (ie, from the second compartment 6B to the penultimate compartment) is a section whose initial boiling point is between 80 and 220 ° C and a final boiling point between 160 and 350 ° C, preferably between 220 and 350 ° C, such as between 220 and 300 ° C or between 300 and 350 ° C.

According to one or more embodiments, the least light hydrocarbon charge 2C (ie, the heavy charge or the last charge) that can be sent to the last compartment 6C is a section whose initial boiling point is between 80 ° C and 350 ° C and more generally between 150 ° C and 350 ° C or even between 220 and 350 ° C and a final boiling point greater than 300 ° C, preferably greater than 350 ° C, such as greater than 500 ° C. According to one or more embodiments, the heavy cut corresponds to a cut whose final boiling point is between 350 and 565 ° C. (e.g. conventional FCC charge such as a VGO).

According to one or more embodiments, the additional hydrocarbon charge (ie, the charge heavier than the charges of the fluidized bed reactor 1) which can be sent into riser or the downer is a section whose initial boiling point is between 80 ° C and 350 ° C and more generally between 150 ° C and 350 ° C or even between 220 and 350 ° C and a final boiling point greater than 300 ° C, preferably greater than 350 ° C, such that higher than 500 ° C. According to one or more embodiments, the heavy cut corresponds to a cut whose final boiling point is between 350 and 565 ° C. (e.g. conventional FCC charge such as a VGO).

According to one or more embodiments, the dense fluidized bed reactor 1 is fluidized by a fluidization gas distributor common to all of the compartments (not shown), for example a single crown which serves each compartment, either by a fluidization member individual to each compartment (not shown), which may commonly be a crown or a "sparger" according to English terminology. Any system for distributing the fluidizing gas in the form of branches is called a sparger. These fluidization bodies, crown or "sparger" are well known to those skilled in the art, and will not be described further. According to one or more embodiments, the fluidizing gas is a mixture comprising the vaporized charge.

According to one or more embodiments, the operating conditions of the dense fluidized bed reactor 1 are as follows:

gas surface speed: between 0.2 and 2m / s;

temperature: between 500 and 800 ° C and preferably less than 750 ° C;

pressure: between 0.1 and 0.6 MPaa; and contact time greater than 1 second.

According to one or more embodiments, the dense fluidized bed reactor 1 is adapted to send into the stripper 13 a solid flow of between 10 and 200 kg / m ² / s. According to one or more embodiments, the dense fluidized bed reactor 1 is adapted to send a solid flow between 30 and 150 kg / m ² / s into the stripper 13.

According to one or more embodiments, the "light cut" is a mixture of the light cut from petroleum crude (eg after a first fractionation) and a part (or all) of the gasoline cut from fractionation column.

According to one or more embodiments, the "intermediate cut" is a mixture of the intermediate cut from petroleum crude (eg after a first fractionation) and a part (or all) of the petrol cut from fractionation column.

According to one or more embodiments, the "heavy cut" is a mixture of the heavy cut from petroleum crude (eg after a first fractionation) and a part (or all) of the light diesel cut (" Light Cycle Oil "or LCO according to English terminology) from the fractionation column.

The catalyst is a solid catalyst (eg density, size and shape of the grains chosen for use in a fluidized bed). The densities, sizes and shapes of catalysts for fluidized beds are known to those skilled in the art, and will not be described further. According to one or more embodiments, the catalyst is an FCC type catalyst, containing for example what is commonly called a matrix made of clay, silica or silica alumina, binder and zeolite, for example from 15 to 50% by weight of zeolite relative to the weight of the catalyst, preferably a Y zeolite and / or a ZSM-5 zeolite. According to one or more embodiments, the catalyst comprises a ZSM-5 zeolite. According to one or more embodiments, the grain density of the catalyst is between 1000 and 2000 kg / m ³ . According to one or more embodiments, the grain density of the catalyst is between 1250 and 1750 kg / m ³ .

In the present application, the term "understand" is synonymous with (means the same as) "include" and "contain", and is inclusive or open and does not exclude other elements not recited. It is understood that the term "understand" includes the exclusive and closed term "consist". Furthermore, in the present description, the terms "approximately", "substantially" "substantially", "essentially", "only" and "approximately" are synonymous with (mean the same as) lower and / or higher margin 10%, preferably 5%, most preferably 1%, of the given value. For example, an effluent comprising essentially or only compounds A corresponds to an effluent comprising at least 90%, preferably at least 95%, very preferably at least 99%, of compounds A. Examples

Example 1: conversion of a light charge as a function of the contact time

The conversion of a gasoline charge from direct distillation (“naphta straight run” according to English terminology) was carried out for different contact times in a dense fluidized bed (LE) reactor composed of 40 g of catalyst, as well as in a riser in which the contact time is significantly shorter.

The properties of the filler are given in Table 1 below.

[Tables 1]

Density at 15 ° C 0.6905 Paraffins (% by weight) 33.7 Isoparaffins (% by weight) 41.3 Olefins (% by weight) 0 Naphthenes (% by weight) 19.2 Aromatics (% by weight) 4.1 Boiling point at 5% (° C) 52.2 Boiling point at 50% (° C) 69.7 95% boiling point (° C) 100.2

PIONA (characterization of n-Paraffin, Iso-paraffin, Olefin, Naphthene, and Aromatic) type compounds of the filler is presented in Table 2 below. [Tables2]

P IP O NOT AT C5 2.31 0.39 0.00 0.00 0.00 C6 23.24 21.20 0.00 10.74 2.54 C7 8.12 19.19 0.00 7.80 1.54 C8 0.00 0.46 0.00 0.61 0.01 C9 0.00 0.02 0.00 0.03 0.00 Total 33.67 41.26 0.00 19.18 4.09

The catalyst comprises a commercial additive containing 40% of ZSM-5.

The reaction temperature is adapted to have a conversion identical to that which one would have in a riser at 540 ° C.

Table 3 below shows the conversion (in% of load weight) as a function of the contact time, obtained in riser (for the shortest contact time) and in a dense fluidized bed (LF).

[Tables3]

Contact time (ms) 150 570 1070 2075 4080 Technology to laugh LF LF LF LF Conversion (% load weight) 33 39 44 52 59

The conversion of the charge increases significantly with the contact time.

For a short contact time, corresponding to that in a riser (contact time here of 150 ms), the conversion is barely half of that obtained in a dense fluidized bed (contact time of 4 s). This clearly shows that to better convert a light load, the implementation of a dense fluidized bed reactor is preferable.

Example 2: yield of light olefins as a function of contact time

For the same load as that presented in the previous example, the following table 4 shows the yield structure in light olefins as a function of contact time, obtained in riser (for the shortest contact time) and in bed dense fluidized (LF).

[Tables4]

Contact time (ms) 150 570 1070 2075 4080 Technology to laugh LF LF LF LF C2 olefins (ethylene) * 7.3 8.6 10.9 15.5 20.3 C3 olefins (propylene) * 14.1 16.7 18.7 19.3 17.6 C4 olefins (butenes) * 6.2 6 6.2 6.2 5.5 Total Olefins * 27.6 31.3 35.8 41 43.4 Gain* 0 13% 30% 49% 57% *:% weight compared to the load

Depending on the product target, the contact time can be adapted. In this example, a contact time close to 2075 ms makes it possible to obtain an optimum in propylene, but it may be interesting to continue to increase it, for example to 4080 ms, in a logic of maximum olefins.

Example 3: optimal contact time according to the charges

Table 5 below shows that for two different charges, the contact time set to obtain similar yields of light olefins is higher for the lightest charge (1454 ms for the charge of density 0.6905; 2652 ms for the density charge 0.67305).

[Tables5]

Charges Density 15 ° C 0.6905 0.67305 Boiling point at 5% (° C) 55.2 35 95% boiling point (° C) 100.2 60 Operating conditions Temperature (° C) 680 680 Contact time (ms) 1454 2652 Yields Dry gas (% weight / load) 26.80 28.50 H2 (% weight) 0.57 0.54 Cl (% weight) 4.54 6.99 C2 (% weight) 6.25 6.10 C2 = (% weight) 15.45 14.87 LPG (% weight) 33.75 30.49 C3 (% weight) 6.42 3.57 C3 = (% weight) 19.35 19.61 total C4 (% weight) 1.59 1.02 iC4 (% weight) 0.60 0.35 nC4 (% weight) 0.99 0.67 total C4 = (% weight) 6.40 6.19 iC4 = (% weight) 2.52 3.64 nC4 = (% weight) 3.88 2.55 C4 == (% weight) 0.00 0.10

EXAMPLE 4

Considering a partitioned reactor with the dimensioning indicated in the following table 6, a solid flow of 80 kg / m ² / s in the stripper, a density of catalyst grain of 1500 kg / m ³ and a gas speed in each 0.8 m / s compartment, the contact times obtained are as follows:

- Contact time in compartment n ° l: 3.0 seconds

- Contact time in compartment 2: 2.6 seconds

- Contact time in compartment 3: 2.3 seconds.

[Tables6]

Reactor diameter (m) 6 Diameter of central stripper (m) 1 Height of catalyst bed in compartment no. L (m) 8 Height of catalyst bed in compartment 2 (m) 7 Height of catalyst bed in compartment 3 (m) 6 Angle of the radial sector of compartment n ° l (°) 160 Angle of the radial sector of compartment n ° 2 (°) 120 Angle of the radial sector of compartment n ° 3 (°) 80

Claims [Claim 1] Device for catalytic cracking in a fluidized bed of a hydrocarbon charge, comprising a dense fluidized bed reactor (1) comprising a first compartment (6A) and at least a second compartment (6B) for at least partially cracking a first hydrocarbon charge (2A ) and at least one second hydrocarbon charge (2B), respectively, the first hydrocarbon charge (2A) being lighter than the second hydrocarbon charge (2B), and in which the first compartment (6A) is adapted to be fed by a catalyst (4) fresh and / or regenerated and the second compartment (6B) is adapted to be supplied with catalyst (4) by circulation between the first compartment (6A) and the second compartment (6B). [Claim 2] Device according to claim 1, in which each compartment (6A, 6B, 6C) comprises a dedicated input (5A, 5B, 5C) for supplying said compartment (6A, 6B, 6C) with a predetermined hydrocarbon charge (2A, 2B, 2C ), the first compartment (6A) being supplied with the lightest hydrocarbon charge (2A) and the following compartments (6B, 6C) being supplied with increasingly heavy hydrocarbon charges (2B, 2C). [Claim 3] Device according to claim 1 or claim 2, in which the first compartment (6A) is adapted to allow the catalyst (4) to pass into the second compartment (6B) by overflowing above a wall (8A-B) separating the first compartment (6A) and the second compartment (6B). [Claim 4] Device according to any one of the preceding claims, in which the last compartment (6C) comprises a lower window (9) for removing the at least partially used catalyst (4) from the last compartment (6C). [Claim 5] Device according to claim 4, further comprising a downward or upward pipe (10) for removing the at least partially worn catalyst (4) from the dense fluidized bed reactor (1), the lower window (9) being connected to the downward pipe or amount (10). [Claim 6] Device according to claim 4, further comprising an ascending or descending gas-solid cocurrent fluidized bed reactor connected to the lower window (9), for treating an additional charge by means of the at least partially spent catalyst (4). [Claim 7] Device according to one of the preceding claims, comprising

Claims (1)

Claims [Claim 1] Device for catalytic cracking in a fluidized bed of a hydrocarbon charge, comprising a dense fluidized bed reactor (1) comprising a first compartment (6A) and at least a second compartment (6B) for at least partially cracking a first hydrocarbon charge (2A ) and at least one second hydrocarbon charge (2B), respectively, the first hydrocarbon charge (2A) being lighter than the second hydrocarbon charge (2B), and in which the first compartment (6A) is adapted to be fed by a catalyst (4) fresh and / or regenerated and the second compartment (6B) is adapted to be supplied with catalyst (4) by circulation between the first compartment (6A) and the second compartment (6B). [Claim 2] Device according to claim 1, in which each compartment (6A, 6B, 6C) comprises a dedicated input (5A, 5B, 5C) for supplying said compartment (6A, 6B, 6C) with a predetermined hydrocarbon charge (2A, 2B, 2C ), the first compartment (6A) being supplied with the lightest hydrocarbon charge (2A) and the following compartments (6B, 6C) being supplied with increasingly heavy hydrocarbon charges (2B, 2C). [Claim 3] Device according to claim 1 or claim 2, in which the first compartment (6A) is adapted to allow the catalyst (4) to pass into the second compartment (6B) by overflowing above a wall (8A-B) separating the first compartment (6A) and the second compartment (6B). [Claim 4] Device according to any one of the preceding claims, in which the last compartment (6C) comprises a lower window (9) for removing the at least partially used catalyst (4) from the last compartment (6C). [Claim 5] Device according to claim 4, further comprising a downward or upward pipe (10) for removing the at least partially worn catalyst (4) from the dense fluidized bed reactor (1), the lower window (9) being connected to the downward pipe or amount (10). [Claim 6] Device according to claim 4, further comprising an ascending or descending gas-solid cocurrent fluidized bed reactor connected to the lower window (9), for treating an additional charge by means of the at least partially spent catalyst (4). [Claim 7] Device according to one of the preceding claims, comprising in addition to a stripper (13) connected to the dense fluidized bed reactor (1) for desorbing hydrocarbons adsorbed on the at least partially used catalyst (4). [Claim 8] Device according to claim 7, in which the dense fluidized bed reactor (1) is directly connected to the stripper (13). [Claim 9] Device according to claim 7 or claim 8, further comprising a regenerator (15) connected to the stripper (13) and adapted to burn the coke formed on the desorbed catalyst (4). [Claim 10] The device of claim 9, further comprising a transport conduit (17) for transporting the regenerated catalyst (4) from the regenerator (15) to the dense fluidized bed reactor (1). [Claim 11] Process for catalytic cracking in a fluidized bed of a hydrocarbon feed, comprising of: at least partially cracking a first hydrocarbon charge (2A) and at least a second hydrocarbon charge (2B) in a first compartment (6A) and at least a second compartment (6B) of a dense fluidized bed reactor (1), respectively , in which the first hydrocarbon charge (2A) is lighter than the second hydrocarbon charge (2B), and wherein the first compartment (6A) is supplied with a fresh and / or regenerated catalyst (4) and the second compartment (6B) is supplied with catalyst (4) by circulation between the first compartment (6A) and the second compartment (6B ). [Claim 12] Method according to claim 11, in which each compartment (6A, 6B, 6C) comprises a dedicated input (5A, 5B, 5C) for supplying said compartment (6A, 6B, 6C) with a predetermined hydrocarbon charge (2A, 2B, 2C ), the first compartment (6A) being supplied with the lightest hydrocarbon charge (2A) and the following compartments (6B, 6C) being supplied with increasingly heavy hydrocarbon charges (2B, 2C). [Claim 13] Method according to claim 11 or claim 12, in which the first compartment (6A) is adapted to allow the catalyst (4) to pass into the second compartment (6B) by overflowing above a wall (8A-B) separating the first compartment (6A) and the second compartment (6B). [Claim 14] Process according to any one of Claims 11 to 13, in which the last compartment (6C) comprises a lower window (9) for removing the at least partially used catalyst (4) from the last compartment. partiment (6C). [Claim 15] Process according to any one of Claims 11 to 14, in which the operating conditions of the dense fluidized bed reactor (1) are as follows: - gas surface speed: between 0.2 and 2m / s; - temperature: between 500 and 800 ° C and preferably less than 750 ° C; - pressure: between 0.1 and 0.6 MPaa; and - contact time greater than 1 second.