FR2548681A1 - REACTOR OF CRACKING AND PROCESSING HYDROCARBONS - Google Patents

Abstract

THE INVENTION RELATES TO CRACKING REACTORS. IT RELATES TO A REACTOR WHICH INCLUDES, IN A METAL ENCLOSURE 16, A MAIN CRACKING ZONE 14, AN EXTRACTION ZONE 20, AND A CARBONING ZONE 34, IN WHICH A DOWN CURRENT FROM A PARTICULAR VEHICLE AND A CURRENT FLOWS ASCENDING FLUIDIZATION GAS. ACCORDING TO THE INVENTION, AN INTERMEDIATE ZONE 24 IS PLACED BETWEEN THE EXTRACTION ZONE AND THE CARBONING ZONE AND IT PROVIDES A SECONDARY CRACKING REACTION AT CONTROLLED TEMPERATURE. APPLICATION TO THE CRACKING OF HEAVY HYDROCARBONS.

Description

The present invention relates to cracking and

hydrocarbon transformation.

  More specifically, the invention relates to a process for the cracking and hydrogen conversion of heavy hydrocarbon feedstocks such as crudes or residual oils, with the formation of lighter liquid hydrocarbons such as naphtha and distillates and products. In the form of a combustible gas It relates in particular to a process and a reactor employing several zones 10 containing fluidized beds of a material in the form of a particulate vehicle, facilitating the cracking of the feedstock in an upper zone and the gasification of the feedstocks. deposits

  coke on the vehicle, in a lower area.

  Considerable work has been devoted to transforming heavy oil feeds in several areas using a circulating particulate vehicle. For example, one process employs a three-zone reactor having an upper main cracking zone. an intermediate zone of secondary extraction and cracking and a lower zone of combustion and gasification, each of the zones containing a fluidized bed of a particulate vehicle whose material is contiguous from one zone to the next. first, cracking on and within the particulate vehicle in the upper zone, and carbon is deposited on the vehicle, and the carbon-charged particles descend counter to an updraft of hot reducing gas in the extraction zone The vehicle is regenerated by partial oxidation of the carbonaceous material in the gasification zone, and is recycled by means of a transport gas s a conduit

  forming a riser emerging in the main cracking zone, by transmitting the heat of reaction.

  Some examples of corresponding patents are US Pat. Nos. 2,861,943, 2,885,342 and 2,885,343 which describe the use of a circulating particulate vehicle so that coke can be deposited when formed. from the cracking of crude oil and residual oil feeds, U.S. Patent Nos. 2,875,150 and 3,202,603 also disclose hydrocracking and multi-bed processes for charging in the form of residual oils and tars, using a particulate vehicle for hydrocracking the heavy oil charge

  with formation of gaseous and liquid fractions.

  In such a process for converting heavy hydrocarbon feeds, it is desirable that a large temperature gradient be maintained in the fluidized bed extraction zone which separates the primary cracking and gasification zones. However, it is difficult to To obtain such a temperature gradient in a steady-state fluidization regime in a dense phase A bad contact between the gas and the solids, between the extraction and gasification zones, can limit the secondary cracking temperatures reached in the extraction zone La Mechanical realization of the fluidized bed extraction zone must take into account that it is adjacent to the gasification zone which is preferably at temperatures of 870 to 1040 ° C. In addition, the setting of the hot solid vehicle stream without recirculating coke requires strangulation in

  a hot valve and thus contributes to the mechanical complexity.

  The method and the apparatus for converting hydrocarbons according to the invention constitute an improvement of known hydrocracking processes, by forming an intermediate zone disposed between the extraction zone and the lower gasification zone, and intended for allow a better regulation of the temperature, circulation of the solids forming the vehicle and reactions

  secondary cracking in this region.

  More specifically, the invention relates to a reactor and a multi-zone conversion process for improving the quality of heavy hydrocarbon feedstocks with the formation of liquid and gaseous products consisting of lighter hydrocarbons. a four-zone reactor having an upper transformation zone or a main cracking zone and a lower gasification or combustion zone, maintained at a relatively high temperature, and separated by an intermediate extraction zone and an intermediate zone placed below. The reactor zones all contain fluidized beds of a particulate vehicle which circulates continuously in the zones and which is fluidized by gas updrafts. The feedstock is cracked in the main fluidized bed cracking zone at a temperature between 45.degree. 0 and 980 C, so that gaseous and liquid products are formed, and The coke-containing vehicle, comprising coke-absorbed refractory particles and liquids having a high boiling temperature, is lowered into the extraction zone which has a packing material. The intermediate zone is advantageously located between the extraction zone and the lower gasification zone so as to allow better adjustment of the temperatures at this location and thus an adjustment of the amount of extraction and secondary cracking of the hydrocarbon residues contained on the carbon-loaded downcomer particulate vehicle, placed in the reactor, before transfer of the vehicle to the lower gasification zone. temperature between 870 and 10400 C by means of steam and an oxygen-containing gas The hot particulate solids, freed of coke, are then returned to the main cracking zone. The intermediate zone thus constitutes a specific means of thermal regulation placed between the zone of cracking and the formation of the reducing gas. extraction and the lower gasification zone, thus allowing a better adjustment of the secondary cracking of the feedstock and a better selectivity of the liquid products obtained. It also minimizes the amount of carbonaceous material transported to the gasification zone by the vehicle, and it allows the adjustment of the vehicle flow and the communication with a solids valve The temperature in the intermediate zone

  is usually maintained between 540 and 870 C.

  The use of the intermediate zone in a fluidized bed allowing a better adjustment of the temperature

  in a four zone reactor has several advantages.

  It allows the use of a more open packed bed or an ordered arrangement in the extraction zone, i.e. having a larger percentage of cavities, improving the fluidization characteristics of the cavity. particulate vehicle and allowing a better adjustment of the yields of hydrocarbon liquids produced and their distribution In addition, the intermediate zone ensures optimal secondary cracking of high molecular weight entities, such as aromatic compounds to several

  nuclei, and it contributes to the production of hydrogen.

  Other characteristics and advantages of the invention will be better understood on reading the description which follows of examples of embodiment and with reference to

  to the accompanying drawing in which: Figure 1 is a schematic sectional elevation of a multi-zone reactor according to the invention; and FIG. 2 shows a configuration variant of the reactor solids recycling device.

of Figure 1.

  According to the invention, the reactor and the hydrocarbon conversion process employ four main fluidized bed zones, which are vertically connected and staggered, the connections being suitably made by a plurality of weir columns and a column conduit. In the process according to the invention, the hydrocarbon feedstock, for example a heavy crude oil or a residual oil, shale oil, bituminous sand bitumen or residues, such products as well as mixtures of these products with charcoal, is preheated and injected at a suitable level into a fog bed of the particulate vehicle, placed in the upper main or primary cracking zone. In addition, certain parts of liquid products distillables can be recycled to this zone to allow for further cracking. It is maintained at a temperature of 450 to 760 ° C. and has a total pressure usually of between 14 and 56 bar, although a higher pressure can be used. The material of the filler is absorbed by the bed of porous particles of the vehicle and is subjected to cracking which forms products in the liquid state and in the vapor state, as well as coke deposits on the vehicle material The hydrogen partial pressure created in the cracking zone by an upcollowing gas limits the The formation of coke and the distribution of product yields is favorable compared to that of a conventional fluidized bed coking operation. The heat required for the main cracking zone comes mainly from the hot particles of the vehicle returned from the lower zone. This hot particulate vehicle is lifted by a carrier gas into a dense phase riser duct, the upper cracking zone, so that the heat of reaction is introduced therein and the sensible heat necessary for the operations is brought to equilibrium In addition, the upward reducing gas formed by partial oxidation in the lower gasification zone of the coke deposited on the vehicle material, goes up in the intermediate and extraction zones and

  forms the reactive and fluidizing gas for the hydrocracking of the charge which takes place in the main cracking zone, with a part of the heat required in the cracking zone This reducing gas essentially contains hydrogen, carbon monoxide, water vapor and carbon dioxide.

  The extraction zone located just below the main cracking zone contains a fixed packing material preferably comprising a plurality of horizontal members and a coarse packing material having a size such that it limits the axial mixing of the solids. by forming a significant vertical temperature gradient of the order of 80 to 420 C, so that a secondary cracking and extraction zone

  by countercurrent and non-isothermal circulation is formed.

  When a coarse particulate packing is used, a packing support structure is used to allow the formation of a sufficient downward flow of the solid particulate matter of the vehicle and a sufficient upward flow of reducing gas in the area of the packing. In order for the liquid hydrocarbons from the lining to be efficiently extracted, many horizontal support structures can be placed without the need for a support structure. A surface removal grid, placed above the extraction zone, can be used to prevent the descent and clogging of the packing material from the extrac- tion zone by agglomerates that can form in the

main cracking area.

  An intermediate zone is located at the lower end of the extraction zone and contains no packing material, but it contains the fluidized particulate vehicle and therefore constitutes a region close to isothermal behavior. The particulate matter descending or in it from the extraction zone is cracked in the intermediate zone. The temperature in this intermediate zone 30 is regulated essentially by a combination of three solid particulate carrier streams, namely: (a) a downward flow from the main cracking zone and flowing to the intermediate zone through the extraction zone, (b) a downflow from the intermediate zone and transmitted to the gasification zone, and (c) hot solids entrained up the gasification zone to the intermediate zone

  by the updraft of reducing gas.

  The temperature in the intermediate zone is therefore usually maintained between 540 and 870 ° C. Thus, this intermediate zone gives a very high control of the exit temperature of the secondary cracking and extraction zone so that the most refractory species and The highest boiling point in the feed is fully cracked. The temperature of the intermediate zone depends essentially on the circulation rate of the solids of the vehicle between the intermediate and gasification zones, this flow being obtained by arrangement of a valve in a spillway column. The intermediate and gasification zones are separated by a grid-like structure which ensures a proper distribution of the gas and solids entrained from the gasification zone and which constitutes the desired thermal barrier between these zones. Intermediate and gasification can work independently over a wide range of usable temperatures in practice, thus enabling optimization of the process in response to variations in load and stress presented by market demand, without the implementation becoming impossible. or saris that the extraction zone requires a mechanical realization practically impossible A sump intended for the removal of agglomerates and integral with the grid is placed at the lower part of the intermediate zone so that clinkers or fine agglomerates can not be collected. at this location and can not prov The sump intended for the removal of this clinker is also arranged so that it can be removed during operation, when such materials are formed during a transient period or in the event of a disturbance of the installation. in derivation with respect to the extraction zone can also be arranged so that it allows an extension of the processing capacity of the multi-zone reactor The use of this bypass conduit allows a stable operation of the main cracking zone in bed fluidized with increased velocities of the rising gas, by formation of an auxiliary capacity allowing a downward flow resulting from the solid particulate vehicle The bypass duct also allows a descent of a reduced flow of the vehicle through the zone d extraction when the implementation of the reactor may make it desirable of the material or packing structure of the extraction zone may be such that a small fraction or most of the sensible heat transmitted to the main cracking zone from the lower gasification zone is due to the vertical thermal diffusivity of solids in the extraction zone This allows

  independent control of the temperatures in the extraction zone, over a wide range of potential operating conditions.

  The upper part of the gasification zone has a reduced diameter and a shape such that the desired flow rate of solids entrainment by the upward reducing gas, corresponding to the criteria set by the thermal balance, is obtained. The grid form separating the gasification and intermediate zones has dimensions such that it operates with a sufficient pressure drop so that the upward reducing gas is well distributed. This grid is formed of a refractory material and is preferably of a form In a dome designed to prevent it from cracking under the action of any significant overpressures A reduction in the solids load in the gasification zone by a slight closure of the valve of the bypass column connecting the intermediate zones and gasification causes a drop in the level of the fluidized bed in the gasification zone and thus a reduction in the entrainment This reduced solids entrainment is obtained by the combined effect of the profile of the gasification zone, as indicated previously,

  and the relative position of the effective separating height of the particles during transport.

  The desired temperature in the gasification zone, between 870 and 1040 C, is maintained by gasification

  and burning the coke deposited on the vehicle or in the vehicle.

  Oxygen and water vapor are injected by circumferentially and vertically transversely directed nozzles in a frustoconical section of the lower end of the gasification zone. Part of the total stream of water vapor is used. for the fluidization of the solids in the gasification zone so that a zone giving a good mixture is formed, the oxygen can be injected into this zone without clinker formation with the vehicle or without sintering thereof The zone s' tilts outward in the injection region

  of oxygen so that the desired uniform rate of fluidization which promotes the dispersion of oxygen is maintained.

  The coke-freed hot solid particulate matter is removed from the base of the gasification zone and passed to a fluidized dense phase transport riser via a solids valve or damper. The solids are then raised by the addition of water vapor or a carrier gas to the dense phase riser conduit and arrive at the cracking zone. In this way, the solids flow rate adjustment can be achieved by arranging the entry points of the drive gas and adjusting the flow rates of the entrainment gas transmitted at these points. The valve or damper that is to be exposed. at high temperatures in the gasification zone, can usually be controlled so that it opens completely or at least without throttling during the Normal Operations A solids extraction assembly is also located at the bottom of the gasification zone. This assembly can be used for removal of sintered or clinker solids that may have formed in this zone. The selection of a suitable particulate vehicle for its absorption properties, pore size and volume, and other suitable characteristics is such that all refractory species boiling at substantially elevated temperature and the coke produced in the process are readily available. upper main cracking zone are collected and that the desired cracking reactions are carried out without agglomeration of the materials The particulate vehicle may be selected from aluminas, aluminosilicates or similar materials having the necessary absorption characteristics and of natural or synthetic type. desired for particles may correspond to a particle diameter

  average between about 40 and 250 pm.

  As shown in FIG. 1, a hydrocarbon feed 10, for example a heavy crude oil or a residual oil, is pressurized at 12 and then preheated at 13 and is injected at an intermediate level into the upper main cracking zone. 14 of a

  multi-zone reactor 16 Zone 14 contains a fluidized bed 15 of a particulate vehicle 17.

  The cracking zone 14 is maintained at a temperature of 450 to 760 ° C. and has a total pressure usually of between 14 and 56 bar. The material of the filler is absorbed by the bed 15 of the porous particles 17 of the vehicle 30 and is cracked so that It forms liquid and vapor products as well as coke deposits on the vehicle and in it. The hydrogen partial pressure is created in the cracking zone 14 by the upward reducing gas which limits the importance of the formation. The resultant products in the vapor phase return to a cyclone separator 50 and are removed as a stream 51. The heat required for the main cracking zone 14 essentially comes from the hot particles. of the vehicle recycled from the lower gasification zone 34 and entrained by a transport gas in a conduit 32 forming a ph-riser densely, up to the upper cracking zone 14, bringing the required heat of reaction In addition, the upward flow of hot reductant gas obtained by partial oxidation in the lower zone 34 of gasification coke 10 deposited on the particles of the vehicle passes successively upwards in the intermediate and extraction zones and forms the reactive and fluidizing gas necessary for the hydrocracking of the feed in the main cracking zone 14 The reducing gas updraft essentially contains hydrogen, carbon monoxide,

  water vapor and cabonic anhydride.

  The extraction zone just below the main cracking zone 14 contains a fixed lining containing a plurality of support members 20 or coarse particulate lining intended to limit the mixing of the solids between the top and the bottom so that a high vertical temperature gradient of 420 C is obtained, this gradient creating a non-isothermal countercurrent extraction and secondary cracking zone When a particulate packing material is used in zone 20, a support structure of the lining is obviously arranged so that it allows

  a sufficient downward flow rate of the solid particles of the vehicle and an upward flow of reducing gas in the extraction zone sufficient for the liquid hydrocarbons from the packing to be extracted efficiently.

  A surface separation grid 22 is preferably placed above the extraction zone 20 to prevent the bed of packing material 35 from being lowered and clogged from the extraction zone by agglomerates which can form. in the main cracked zone

  At the lower end of the extractive zone

  An intermediate zone 24 is devoid of packing material but contains the fluidized particulate vehicle and is therefore close to the isothermal conditions. The high boiling temperature liquid remaining on or in the particulate vehicle from the The temperature in this zone 24 is adjusted essentially by a combination of the streams of the particulate solids of the vehicle. The solids are lowered from the main cracking zone into the extraction zone and then through a cracking in the intermediate zone 24. in the intermediate zone in which they undergo additional heating, and then descend from the intermediate zone to the gasification zone. In addition, the hot solids are driven upwards from the gasification zone by raising a

  reducing gas stream in the intermediate zone.

  The temperature of the intermediate zone is thus usually maintained between 540 and 870 ° C. and preferably between 590 and 820 ° C. The temperature of the intermediate zone is essentially regulated by the flow rate of the solids of the vehicle between the intermediate zones and the intermediate zone. This gasification is achieved by arranging the valve or larder 25 placed in the column 26. For example, when the damper 25 is opened and a greater amount of solids is lowered into the gasification zone 30, the level of the gasifier is increased. fluidized bed in this area goes up and a greater amount of solids is driven upwards

  in the intermediate zone 24 by the updraft 30 of reducing gas.

  The intermediate and gasification zones are separated by a grid-like structure 28 which constitutes a thermal barrier which makes it possible to limit to the gasification zone the high temperatures necessary for a profitable gasification of the coke residue. A sump for extracting agglomerates , integral with the grid, is placed at the lower part of the intermediate zone so that it prevents a bad distribution of the ascending hot reducing gas which could be due to fine agglomerates or to clinkers which could collect therein. The collection of these clinkers is also carried out in such a way that it allows continuous extraction when clinkers are formed during a transient period or during

a disturbance of the operation.

  A conduit 18 for bypassing the extraction zone

  and a valve 19 are intended to increase the charge processing capacity of the multi-zone reactor 16.

  The use of this bypass allows stable operation of the main fluidized bed cracking zone for higher gas up rates than for a particular nominal design, by forming an auxiliary capacity giving a downward flow resulting from the vehicle. The bypass duct also makes it possible to reduce the flow of the vehicle downwards in the extraction zone when the use of the reactor requires it. The embodiment of the packing structure or the lining of the zone extraction

  is such that a small fraction or most of the sensible heat supplied to the main cracking zone from the lower gasification zone is due to the thermal diffusivity of the solids through the dye zone. extraction.

  The upper portion 32 of the gasification zone 30 has a reduced diameter and a profile such that it gives the desired solids entrainment rate by the reducing gas updraft, corresponding to the criteria set by the heat balance. , the plate 28 forming the grid separating the gasification and intermediate zones has a dimension such that it gives a sufficient pressure drop so that the reducing gas rising from the zone 32 is well distributed. This grid 28 is formed of a material refractory such as "Cerox 600", available from CE Refractories Inc. This grid is preferably dome-shaped preventing its cracking under the action of significant overpressures which may correspond to a high multiple of the nominal value Uneréduction of the load of materials solids transferred to the gasification zone by slight closing of the valve 25 of the column 26 causes a reduction in the level of the It is fluidized in the upper part of the gasification zone 30 and thus reduces the upward entrainment of the hot particles of the cokeless vehicle 17. The reduced solids entrainment is obtained by the combined effect of the above mentioned profile. the gasification zone 32 and the relative position of the separation effective height

particles by transport.

  The desired temperature for the gasification zone between 870 and 1040 ° C. is maintained by gasification and combustion of the coke deposited on the vehicle 17 and in the latter. The oxygen is injected with the steam by a series of nozzles. placed circumferentially and

  vertically in a transverse direction in a frusto-conical section 34 formed at the base of the gasification zone 30.

  Part of the total amount of water vapor is used for the fluidization of the vehicle solids in the gasification zone with formation of a well-mixed zone, in which oxygen can be injected without production of clinkers or sintering. vehicle material. The zone flares outward at the lower end so that the desired uniform rate of fluidization which promotes the oxygen distribution is maintained. A separate row of water vapor nozzles is preferably placed at the bottom. In this case, oxygen can be injected with water vapor in order to increase the stability of the fluidized bed and to ensure that the penetration of the bed is minimal. The hot, coke-freed solid particles are removed through a side duct 38 from the base of the gasification zone and back up into a fluidized dense phase riser 40 through a solids circulation register 42, the lateral duct and the reverse duct creating a zone of high resistance The particulate solids are then raised by introduction of a transport gas such as water vapor or a combustible gas produced at 41 and / or 41a, penetrating the In this manner, the flow rate control of the hot solid particles can be achieved by arranging the inlet points of the dense phase riser 40, and they are transmitted upwards to the main cracking zone 14. In this way, The control or valve 39, which must be exposed to the elevated temperatures of the operating zone, is used to control the entrainment gas flow at these points. gasification, can

  usually be controlled so that it is wide open or at least without throttling in normal operations.

  An enlarged change of direction member 42, having a hard impact surface 44 formed of a refractory material, is intended to return solids to the zone

main cracking 14.

  A conduit 46 and a solids extraction register 47 are also located at the bottom of the gasification zone. This device can be used for the removal of the sintered solids.

  forming a clinker out of the gasification zone.

  Depending on the feedstock used, the liquid and gaseous products with a small amount of unconverted coke having a small particle size and a greater proportion of small particle size solids leave the upper zone of the reactor as a stream 51 and This separating operation removes from the produced gas stream the particles which can remain coke and solids in the form of a stream which can be returned to the reactor. The resulting effluent stream 54 from the cyclone is then usually cooled to 55, for example by a stream of oil, or otherwise cooled.

  so that its temperature is limited and additional adverse reactions are limited or prevented.

  The cooled gas and liquid are then separated by a conventional fractionator 56 giving a product gas stream 57, a liquid naphtha stream 58, and a liquid light distillate stream 59 and a heavy distillate liquid fraction. product 50 The light distillate usually has an initial boiling point of about 205 ° C and a final boiling point of 315 ° C to 540 ° C; the heavy distillate has an initial boiling point of 315 ° C. or higher. If appropriate, a portion 61 of the heavy fraction 59 can be returned to the main cracking zone 14 to undergo further reaction. part of the heavy liquid stream 60 can be returned to the intermediate zone 24 to undergo further cracking reaction In addition, part of the stream 57 can be returned for use

  as a gas 41 or 41a driving in the conduit 40.

  FIG. 2 represents a variant of recycling of the removed hot particulate solids

  coke to the main cracking zone The hot solids of the coke-free vehicle descend through a regulating damper 65 and then into an upstanding side portion 66 of the conduit 40.

EXAMPLE

  A charge formed from an oil residue enters the upper main fluidized bed cracking zone of the four-zone reactor and undergoes hydrocracking on a particulate vehicle. The operating conditions used and the products obtained are disclosed in FIG.

the next board.

BOARD

  Loads Residue, m 3 / d 815 Oxygen, t / d 174 Water vapor, t / d 196 Temperature, C Main cracking zone 538 Extraction zone 538-760 Intermediate zone 760 Gasification zone 982 Pressure, bars 17, 5 Products Combustible gas, m 3 / d 365,000 Naphtha, m 3 / d 373 Distillate 2044820 C, m 3 / d 236

  In this example, a portion of the distillate stream produced between 204 and 482 ° C is recycled to the main cracking zone at 0.5 volume of recycle stream per 1.0 volume of fresh feed.

  A fluidized bed extraction zone, comprising a packing, gives a temperature gradient of 18 to 110 C per meter of height and distributes the reducing gas obtained to form the fluidizing gas of the main cracking zone. resulting flow rate of 113.5 t / h of vehicle descends countercurrently from the fluidizing reducing gas In the intermediate zone, below the extraction zone, an isothermal bed is maintained at approximately 760 C by withdrawing 177 t / h of the vehicle descending through the branch line and entering the gasification zone, and driving 63.5 t / h of the vehicle at about 980 C of the gasification zone in front of the gate with the hot reducing gas produced in

this zone.

  Of course, various modifications may be made by those skilled in the art to the reactors which have just been described solely as non-limiting examples.

  without departing from the scope of the invention.

Claims (5)

  A reactor for cracking and transforming heavy hydrocarbon feedstocks to liquid and gaseous lighter hydrocarbon products in a plurality of zones, the reactor being characterized by comprising: ) a reactor metal enclosure (16) to be pressurized, (b) a main cracking zone (14) located at the upper end of the reactor and intended to provide a fluidized bed reaction, (c) a device (10) introducing a hydrocarbon feedstock into the main cracking zone, (d) an extraction zone (20) placed below the main cracking zone and containing a fixed packing material, (e) a gasification zone (34) at the lower end of the reactor for providing a fluidized bed gasification reaction; (f) an intermediate zone (24) located between the extraction zone and the gasification zone; gasification and for providing a secondary cracking reaction at a controlled temperature, (g) a device (35) for introducing a combustion gas and steam into the lower gasification zone (34), ( h) a device (40) for recycling a hot particulate vehicle from the lower gasification zone (34) to the upper cracking zone (14), (i) a device (41, 41 a) of introducing a carrier gas at the lower end of the conduit device (40), and (j) a device (50) for removing   produced gases resulting from the main cracking zone of the reactor.   2 reactor according to claim 1, characterized   in that each zone contains a particulate matter   a vehicle which is fluidized and recycled from the upper cracking zone (14) successively in the extraction zones (20) and intermediate (14) to the lower gasification zone (34) by descent, and which is recycled upwardly through an outer duct (40) and an adjustment damper (39) to the upper zone main cracking 14.   3 reactor according to claim 1, characterized in that a gate (28) having openings is placed between the intermediate zone (24) and the gasification zone (34) so that it regulates the flow of particulate solids between said areas.   4 reactor according to claim 1, characterized in that a grid (23) having openings and formed of a refractory material is placed at the lower end of the extraction zone (20) so that it supports a   coarse particulate packing material.   Reactor according to claim 1, characterized   in that the extraction zone (20) contains an ordered arrangement of horizontal support members.   Reactor according to claim 1, characterized in that it comprises a device (50) for phase separation, coated with a refractory material and placed above the main cracking zone (14) so that it removes 25 the particulate vehicle and returns it to the cracking zone. A reactor for cracking and transforming heavy hydrocarbon feedstocks into liquid and gaseous lighter hydrocarbon products, the reactor comprising a plurality of zones and characterized by comprising: (a) a metal enclosure (16) forming a reactor to be pressurized, (b) a main cracking zone (14) located at the upper end of the reactor and containing a particulate carrier for fluidized bed reaction, (c) a device ( 10) for introducing a hydrocarbon feed into the main cracking zone; (d) an extraction zone (20) located below the main cracking zone and containing an ordered arrangement of horizontal members of sufficiently spaced apart to allow formation of a downflow of the particulate vehicle, (e) a gasification zone (34) at the lower end of the reactor and containing a vehicle particulate means for providing a fluidized bed gasification reaction; (f) an intermediate zone (24) positioned between the extraction zone and the lower gasification zone and intended to provide secondary cracking within a controlled range of temperatures; g) a conduit device (35) for introducing a gas containing oxygen and water vapor into the lower gasification zone, (h) a device (40) for recycling a particulate vehicle from the lower gasification zone to the upper cracking zone, the pipe being placed outside the reactor enclosure, (i) a device (41, 41 a) for introducing a transport gas to the lower end of the conduit device (40), and (j) a device (50) for the extraction   gaseous products resulting from the main cracking zone of the reactor enclosure.