MXPA98002918A - Perfected process and installation for the regeneration of a catalyst for the production of aromatic compounds or reformac - Google Patents

Abstract

The invention relates to a process and an installation for regenerating a catalyst for producing aromatics and particularly for reforming, the catalyst being in a moving bed, comprising the steps of combustion, oxychlorination, and calcination, in which it is introduced for the stage of oxychlorination, at least one chlorinating agent, at least one gas containing oxygen, and water, so that the molar ratio H2O / HCl is from 1 to 50, the oxychlorination step is carried out in the presence of an oxychlorination gas which contains less than 21% oxygen and at least 50 ppm by weight of chlorine (calculated as HC1), and at a temperature of 350-600 ° C and the combustion stage develops in at least two combustion zones, each zone is separated from the adjacent zones, and in each zone at least one gas charged with oxygen is introduced, the gases produced are extracted at the level of each zone, and the severity of the operating conditions increases in the sense of Catalyst circulation

Description

PROCESS AND INSTALLATION PERFECTED FOR I. REGENERATION OF A CATALYTIC FOR THE PRODUCTION OF AROMATIC OR REFORMATION COMPOUNDS FIELD OF THE INVENTION The invention relates to the processes in moving bed for the production of aromatic hydrocarbons, and particularly to the reformation. It relates more particularly to the regeneration of the catalyst used, intended to provide its initial catalytic characteristics.

BACKGROUND OF THE INVENTION The catalyst generally comprises a support (for example formed of at least one refractory oxide, the support can also include one or more zeolites), at least one noble metal (preferably platinum), and preferably at least one promoter metal (for example tin or rhenium), at least one halogen and optionally one or more additional elements (such as alkaline, alkaline earth metal, lanthanide, silicon, elements of group IV B, non-noble metals, elements of group III A, REP: 27252 etc.). Catalysts of this type contain, for example, platinum and at least one other metal deposited on a chlorinated alumina support. In general, these catalysts are used for the conversion of naphthenic or paraffinic hydrocarbons, capable of being transformed by dehydrocyclization and / or dehydrogenation, in the reformation or for the production of aromatic hydrocarbons (for example benzene, toluene, ortho, meta production). or paraxylenes). These hydrocarbons come from the fractionation of crude oils by distillation or other transformation processes. These catalysts are widely described in the literature.

BRIEF DESCRIPTION OF THE INVENTION One of the means to increase the yields of these processes of reforming or producing aromatics is to reduce the "operating" pressures, to which the different reactions of interest are made. For example, 30 years ago the reforming reactions were carried out at 40 bars; 20 years ago at 15 bars. At present, it is normal to see reformers working at pressures below 10 bars, especially between 3 and 8 bars.

The improvement of the reactions is beneficial due to the low pressure, is accompanied by a faster deactivation of the catalyst by carbonization. The coke, composed of high molecular weight and consisting essentially of carbon and hydrogen, is deposited on the active sites of the catalyst. The molar ratio H / C of the formed coke varies from about 0.3 to 1.0. The carbon and hydrogen atoms that form the condensed polyaromatic structures in which the degree of crystalline organization is variable depending on the nature of the catalyst and the operating conditions of the reactors. Although the selectivity of the conversion of the hydrocarbons into coke is very low, the coke content accumulated on the catalyst may be important. Typically, for fixed bed units, these contents are between 2.0 and 20.0 to 25.5% by weight. For units with circulating bed, these contents are less than 10.0% by weight. The deposition of coke, faster at low pressure, needs an equally faster regeneration of the catalyst. The current regeneration cycles may decrease up to 2-3 days. The patent EP-A-0,378,482 of the applicant, discloses a process of continuous regeneration of a reforming catalyst or production of aromatics, which allows to mitigate these inherent drawbacks to these increasingly shorter cycles. One of the stages of regeneration is the oxychlorination of the catalyst. The present invention relates to this stage. According to EP-A-0,378,482, the used catalyst circulates progressively from top to bottom in a regeneration chamber or is successively in a first zone of mobile and radial bed of combustion, a second moving and radial combustion bed zone, a moving axial oxychlorination bed zone and "an axial moving bed zone of calcination, and (a) in the first combustion zone, the catalyst is treated under a pressure of 3 to 8 bars substantially equal to that prevailing in the first reforming reactor, at a temperature comprised between 350 and 450 ° C by a combustion gas based on an inert gas circulating cocurrently of the catalyst, containing 0, 01 to 1% oxygen by volume, this combustion gas comes from a gas washing zone from the combustion of oxychlorination and from calcination (b) in the second combustion zone, the catalyst is treated under a pressure from 3 to 8 bars sensibly equal to that prevailing in the first reactor at a temperature higher than at least 20 ° C, the temperature that predominates in the first combustion zone, in the presence of the gas coming from the first combustion zone ny in the presence of an inert complement gas, to which is added up to 20% by volume of oxygen, so that the catalyst is in contact with a gas containing 0.01 to 1% oxygen by volume, this gas circulates at cocurrent of the catalyst. (c) the combustion gases are evacuated from the second combustion zone and sent to a "wash cycle" after being lightly mixed with the gases removed from the oxychlorination zone and the calcination zone. axial zone of oxychlorination, the catalyst is treated cocurrently with a mixture of a gas coming from the calcination zone and the chlorinated gas for 30 to 60 minutes, the mixture forms an oxychlorination gas containing from 4 to 10% by volume of oxygen, under a pressure of 3 to 8 bars, the water content is of the order of 500-7000 ppm, without added water, the water comes from the gas coming from the combustion, washing and drying that is used in part for the oxychlorination , but also essentially of the calcination. (e) in the axial zone of calcination, the catalyst is treated for 45 to 80 minutes countercurrently between 350 and 550 ° C under a pressure comprised between 3 and 8 bars, for a part of the gas coming from the washing cycle and from a drying zone, which does not contain more than 100 ppm of water.

DETAILED DESCRIPTION OF THE INVENTION The inventors have ascertained that the control of the operating conditions of the process can be improved and a proportion of gases has been sought which allow the operating conditions of the combustion stages to be precisely controlled, and also of the calcination stage. The method and the device according to the invention meet these objectives. More precisely, the process according to the invention is a regeneration process of a mobile bed catalyst for the production of aromatic or reforming hydrocarbons, said catalyst comprises a support, at least one noble metal and at least one halogen, the method comprises a combustion stage with the treatment of the mobile bed catalyst in at least two successive combustion zones, and an oxychlorination stage and a calcination stage in which each combustion zone is separated from the adjacent combustion zones, so that it can pass the catalyst and prevents the passage of gases, in each zone of the combustion stage at least one oxygen-containing gas is introduced and the gases produced are extracted from each zone, the severity of the operating conditions in each zone of the combustion stage it is increased in the direction of the catalyst circulation, it is introduced for the oxygen stage At least one chlorinating agent, at least one gas containing oxygen, and water, so that the molar ratio H20 / HC1 is from 1 to 50, the oxychlorination stage is carried out in the presence of an oxychlorination gas containing less of 21% oxygen and at least 50 ppm by weight chlorine (calculated as HCl), and at a temperature of 350-600 ° C. The process is carried out in a moving bed or with an intermittent recirculation of the catalyst (in this case, each stage develops in at least one different zone, the catalyst leaves from one zone to the other). The regeneration begins with a combustion stage of the carbon material. It is followed by an oxychlorination stage and after a calcination stage.

The gases that come from the combustion and the gases that come from the oxychlorination are extracted separately from the regeneration process, in a general way. To avoid mixing these gases, it is advantageous to place a plate or other means to separate the combustion and oxychlorination zones in the moving bed processes. On the contrary, in these moving bed processes, the gases coming from the calcination can generally pass freely to the oxychlorination zone. As far as the combustion stage is concerned, it develops in at least two adjacent adjacent and separate * zones, ie the catalyst leaving a combustion zone goes directly to the next combustion zone, it can not undergo treatment between the two zones, the gas extracted from a combustion zone, is sent at least in part, and preferably in its entirety, to the next zone (in the direction of the catalyst circulation) with an optional complement of oxygen (for example air). In general, the severity of the operating conditions is obtained by increasing the temperature and / or oxygen content of the incoming gas. Preferably, for each zone in oxygen content of the incoming gas is between 0.01-2%, preferably 0.5-1.5% and generally higher than 0.5%, the temperature of the gas entering this comprised between 350-600 ° C, preferably 400-600 ° C, the residence time of the catalyst in an area is comprised between 5 minutes-3 hours and the PPH (hourly mass flow of the gas / mass of the catalyst in contact with the gas) is comprised between 1-50 h "1. Advantageously, the combustion stage ends with a last control zone, called control of the end of combustion, in which the consumption of oxygen is less than 10% of the oxygen that enters said zone. The temperature is preferably, substantially constant. Preferably, the control zone is located in the lower part of the last combustion zone, after "the final part of the front of the flame." In addition, a gas containing oxygen in an amount is generally introduced into the control zone. higher than that of the gas entering the upper levels (in the direction of the catalyst circulation) Thus, in the present invention, combustion is defined in several zones (or stages), wherein each stage is characterized by a temperature predominant in said step, an inlet temperature of the oxygen-containing gas, an oxygen content of the entering gas, a gas flow rate and a duration of exposure of the charred catalyst to these conditions, in order to have a more efficient combustion .

The catalyst that has undergone the combustion stage is ready to undergo an oxychlorination stage. This develops in one or several zones, of the axial or radial type. At least one chlorinating agent, at least one gas containing oxygen and water, is introduced into the oxychlorination zone. The chlorinating agent may be chlorine, HCl, or a halogenated hydrocarbon containing at least 4 carbon atoms, and from 1 to 6 chlorine atoms (for example CC14) or any known chlorinating agent in these regeneration processes, for release the chlorine; It is preferably introduced with the oxygen-containing gas. "It will be advantageously introduced into the lower part of the oxychlorination zone, so that it flows countercurrently to the catalyst, when the oxychlorination zone is axial. introduced is such that the concentration in chlorine (calculated as HCl) in the gas in contact with the catalyst in the oxychlorination zone, called the oxychlorination gas (ie, for the moving-bed processes, the gas introduced in the oxychlorination zone). + the gas coming from the calcination zone) is at least 50 ppm by weight, in general 50-8000 ppm by weight, advantageously, above 650 ppm by weight, and preferably, comprises between 1000 and 8000 ppm by weight, it will also be preferred, for technological reasons (linked to corrosion, for example or to the subsequent treatment of chlorinated gases), to work with contents that do not exceed 4000 or 5000 ppm by weight. also in the oxychlorination zone, at least one gas containing oxygen. Advantageously, this gas comprises a part of the gas coming from the combustion, washing and drying stage preferably, added with an oxygen supplement, such as air for example. In the processes of moving bed with axial zone of oxychlorination, this gas preferably circulates countercurrently of the catalyst. The catalyst is in the oxychlorination zone in contact with the gas thus introduced and also in contact with the gas coming from the calcination zone, still charged with oxygen and containing a little water resulting from the calcination. The oxygen content of the oxychlorination gas is less than 21% (volume). It is generally above 10% by volume. It will be noted that according to the invention, in a preferred embodiment in the moving bed processes, and contrary to the prior art EP-A, 0 378 482, it is introduced in the oxychlorination stage (the axial oxychlorination zone by example) at least one gas containing oxygen, independently of the gas containing the oxygen introduced in the calcination stage (the axial calcination zone, for example).

It can also be seen without departing from the invention, that only the chlorinating agent and water are introduced into the oxychlorination stage, the good distribution of chlorine and water is therefore more delicate, the gas containing Oxygen comes only from the calcination zone. In a novel way with respect to EP patent, 0 378 482, water is introduced into the oxychlorination stage. It is advantageously placed in a mixture with the gas containing the introduced oxygen. The amount of water thus introduced is within * the molar ratio of H20 / HC1 from 1 to 50, generally this ratio is at least 3 and preferably is from 4 to 50, or from 4 to 30, advantageously from 7 to 50. to 50 and more preferably from 7 to 30. Water is provided in the liquid form or preferably in the form of steam. The oxychlorination gas is therefore highly charged with water, and its water content is higher than 7000 ppm, and is generally at least 8000 ppm to 10000 ppm by weight, and preferably greater than 10000 ppm by weight. The redispersion of the noble metal is obtained in the presence of oxygen, chlorine and water under the stated conditions, and at the temperatures in the oxychlorination stage of 350-600 ° C, preferably at 350-550 ° C, but most commonly at least 450 ° C, and preferably between 490 and 530 ° C. The residence time of the catalyst in the oxychlorination stage is often less than 2 hours and is generally established between 45 minutes and 2 hours. The predominant pressure in this zone must be balanced with the pressures of the adjacent areas, in the case of catalyst circulation, and 3-8 bars for the mobile bed processes of regeneration of the catalyst that works in the pressure reforming processes reduced. In mobile bed processes, the oxychlorination gas also contains a gas that comes from the "calcination zone"; in this calcination zone, a gas containing oxygen and less than 1% in mol of water is introduced, and preferably less than 0.1% of water and better, at least 0.05% of water. Generally, the water content will be less than 150 ppm per mole, better, less than 100 ppm per mole, and advantageously, less than 50 ppm per mole. The oxygen-containing gas can be air. Advantageously, this gas comprises a part of gas that comes from the stage of combustion, washing and drying, and added with a complement of oxygen (air). In this advantageous case, the oxygen content of the gas introduced for the calcination step is less than 21% by volume. In a general manner, the oxygen content of the gas introduced for the calcination stage is more than 21% by volume.

The temperature of the calcination stage is comprised, in a known manner, between 350 and 600 ° C, and preferably between 350-550 ° C. The oxygen-containing gas circulates countercurrent to the catalyst in the processes with a moving bed with an axial calcination zone. In general, the residence time is less than 1 hour. In order to be able to strictly control the operating conditions in the oxychlorination zone, it is preferably operated without recycling the oxychlorination gases. The absence of recycling also allows a more precise control of the percentage of oxygen, and allows to obtain the high oxygen contents (absence of dilution) economically. But the modalities may include recycling. In the absence of recycling (preferred case), the oxychlorination gas (or the purge of this gas if it is recycled) leaves the oxychlorination zone and is discarded outside the facility (into the atmosphere, for example) after the treatment to eliminate at least the chlorinated impurities. It is also of interest to dry the gas that comes from combustion, provided in the oxychlorination zone, when this is the case, in order to control the amount of water present in the oxychlorination gas from the amount of water added. This drying can be carried out on the gas extracted from the combustion before its fractionation to obtain a part in the oxychlorination zone, or on the fractional part. The air is likewise, dried preferably. Under the conditions of the process according to the invention, a remarkable improvement in the redispersion of the metal phase of the catalyst is obtained, with respect to the prior art. The dispersion state of the metal phase of the catalyst is determined quantitatively by the chemisorption technique H20 / 02. The procedure will be better understood from the description of Figure 1, which shows the installation object of the invention. Another object of the invention is an installation for the regeneration of reforming catalyst or the reduction of aromatics comprising a support, at least one noble metal and at least one halogen, at least one inlet conduit (1) and one conduit (4). ) out of the catalyst of the chamber, said catalyst in the form of a moving bed that passes successively through the combustion, oxychlorination and calcination zones, the chamber comprises: at least two radial combustion zones (A1, A2), arranged in series, and between the combustion zones are placed separation means that allow the passage of the catalyst between said areas in the conduits for this purpose, but that prevent the passage of gases between said zones, a zone (FC) of control of end of the combustion, located in the lower part of the last combustion zone, - at least one duct (30) for the introduction of the oxygen-containing gas in the first combustion zone, * to the a duct (32) for the evacuation of a gas from a combustion zone and for its introduction into the next combustion zone, at least one duct (31) for the introduction of oxygen-containing gas into the control zone, less a conduit (5) for the evacuation of the gases coming from the combustion stage outside the chamber, said conduit is located before the oxychlorination zone, the chamber comprises at least one means for the re-cooling of said gases, less means for treating said gases to eliminate impurities, at least one means for drying the gases, and at least one means for its compression, at least one conduit (9) for evacuating a part of the gases that come from combustion, compressed and gathered in the ducts (30) and (31), at least one duct (10) to evacuate the other part of the gases that come from the combustion, compressed in said duct and placed in at least one means of heating (1 6) of the gases, and said conduit is joined to at least one conduit (17) that carries a part of at least said gases to the oxychlorination zone., said duct (17) is connected to at least one duct (20) for the introduction of water and at least one duct (19) for the introduction of a chlorinating agent, at least one duct (18) for the introduction of a gas containing oxygen in the calcination zone, - at least one conduit (21) for evacuating gases coming from the oxychlorination zone having at least one means (22) for the treatment of said gases before their evacuation of the installation. Advantageously, the duct (9) comprises at least one means for heating the gas brought to the control area. Advantageously, at least one heating means (36, 37) of the gas is placed on each duct (30) and (31).

Advantageously, the duct (5) comprises at least one means of re-cooling, followed by at least one dryer, then, of at least one compression means. The global proportion of the gases at the chamber level ensures optimized combined operation of the combustion, oxychlorination and calcination zones. Thus, the gases that come from the combustion stage are re-cooled, treated to eliminate the impurities, dried, compressed and then split into two flows; the first flow is, after being supplied with oxygene and eventually reheated, sent to the first combustion zone, the second flow is, after being supplied with oxygen, with water and chlorination agent, and then heated, sent to the oxychlorination stage, the gases that come from oxychlorination are treated and evacuated outside the installation. In the case of figure 1, which has two combustion zones, the zones are separated so as to let the catalyst pass and prevent the passage of gases, the second combustion zone comprises in its lower part a control area of the end of the combustion, and the gas extracted from the first combustion zone is sent in its entirety in the second combustion zone, after a complement with oxygen, the gas coming from the second combustion zone is re-cooled, it is treated to eliminate impurities, it is purged, dried, compressed and then separated into two streams; the first flow is introduced after being supplied with oxygen in the first combustion zone and then eventually overheated in the control zone; the second stream is added with a dry gas containing reheated oxygen and sent to the oxychlorination zone after the addition of water and the chlorinating agent. According to one embodiment, the first flow is separated into two fractions, one which is introduced after the supply with oxygen in the first combustion zone; the other is added with oxygen, reheated and introduced into * the control zone. In another embodiment, the first flow is separated into two fractions, each of which is added with oxygen and reheated before introduction, in one of the first combustion zones, and the other in the control zone. Furthermore, according to one embodiment, the second superheated flow is separated into two fractions, one which is sent to the oxychlorination zone after the addition of water and chlorination agent, the other is sent to the calcination zone. It is also possible, in another embodiment, to reheat the two fractions that come from the first flow or only the fraction that is introduced in the control zone.

In a conventional manner, the catalyst used for regeneration enters the upper part (2) of the regeneration chamber E through the conduit (1). The catalyst is then introduced through the conduits or legs (3) into a first combustion zone Al. In this zone the catalyst undergoes a first combustion or combustion with the aid of a gas containing oxygen introduced through the conduit (30). In general, the combustion zones are of the radial type, and preferably annular, the bed then circulates in the annular space delimited by two coaxial cylindrical walls, the gas enters through one wall and exits through the other. then in this first combustion zone, it is withdrawn from said zone by the conduit (32), and is at least partly reintroduced, and preferably completely, in the second combustion zone A2, in which the catalyst circulates. In a general manner, the gas extracted from a combustion zone is reintroduced at least in part, and preferably in its entirety, in the next combustion zone.An oxygen supplement takes place, if necessary, and by a conduit ( 35) This arrangement allows a maximum utilization of the remaining oxygen and a minimum oxygen supplement In accordance with the invention, the combustion zones Al and A2 are typically separated so that they allow the catalyst to pass through but prevent the passage of gases, for example, the direct passage of gases in Al towards A2. The expert in the field will choose the most adapted means to fulfill this function. In the embodiment of figure 1, a plate (29) is placed to this effect between the zones Al and A2 over the entire sequence of the chamber E of * regeneration, with exceptions of the sections reserved for the passage of the catalyst (legs or other conduits). Of course, some of the gas passes into zone A2 with the catalyst in the legs, but it is a minor part of the gas. The gas then passes to this second combustion zone and is extracted from said zone by the conduit (5). This separate proportion of the gases at the level of each combustion zone makes it possible to know precisely at all times the temperatures of the gases entering and leaving and their quantities of oxygen. A maximum use of oxygen, this proportion allows a control of the combustion of the coke by controlling the operating conditions at the level of each zone.

An operation to control the end of combustion is carried out in a last zone of the combustion stage. In the embodiment of FIG. 1, this operation is carried out in the lower part (in the direction of the catalyst recirculation) of the last combustion zone A2, this lower part therefore constitutes a control zone FC. In another embodiment not shown, the control zone FC is a zone not included in the last combustion zone A2. The control zone FC is distinguished from a combustion zone in which the oxygen consumption is in the FC zone approximately less than 10% of the oxygen that enters. Advantageously, the prevailing temperature there remains substantially constant (variation of 3% maximum and better than 2% maximum) with measurement errors and thermal waste. A gas containing oxygen enters the zone FC through the conduit (31), the oxygen is carried by the conduit (34), the gas that is extracted after passing through the zone FC through the conduit (5), for which the evacuation of the gas that has passed through the last combustion zone A2 is also carried out. The expert in the field will choose the means to measure the oxygen consumption in the FC zone. For example, the variation of the oxygen content between the input and output of the FC zone can be measured from a variation in the input content (to the same total gas flow) and the measurement of the variation in the content at the exit of the zone. In a general way, if the operation of the preceding stages is correct, the oxygen consumption in the FC zone must be reduced (less than 2-3%). Another means is to place means for measuring the temperature and / or oxygen content either on the gas leaving (for example, in the case where the gas - regardless of the other gases coming from the "combustion"), either At the level of the wall through which the gas from the FC zone exits, the means for measuring the temperature of the catalytic bed or the catalyst entering and leaving the control zone can also be adapted. the proper functioning of the combustion stages, and by the independent proportion of the gases in each stage, can be quickly and easily remedied the combustion deficiencies by varying the temperature or the percentage of oxygen in one or several zones. the comparison of the oxygen contents or the temperatures in the gas and / or the catalyst leads to variations outside the admissible values for the procedure (less than 10% for oxygen and at least 3% for the temperature) then at least one operating condition of the at least one combustion zone is modified, so that the difference is corrected. This can be due to the modification of the oxygen content and / or the temperature of the gas that enters). The operating conditions are chosen for each zone and are strictly controlled at the level of each zone (contrary to the prior art) in order to reduce as much as possible the harmful effect of combustion on the catalyst. Each stage (zone) collects at least one gas containing oxygen at a PPH between 1 and 50 h "1, and preferably 10-40 h "1, and more preferably 15-35 h" 1, a temperature T comprised between 350 and 600 ° C, preferably 400 and 600 ° C, an oxygen content 02, when very much 2% and preferably 0.5-1.5%, - each zone has a volume V corresponding to a catalyst residence time of 5 minutes to 3 hours. For each zone, the inlet temperature of the oxygen-containing gas and the oxygen content are such that: the maximum temperature at the outlet of the bed is less than a maximum allowable value, which is a function of the materials used (for example, 770) ° C for poorly alloyed steel), - the maximum temperature rise between the inlet and the outlet of the bed is less than 200 ° C, preferably of the order of 100 ° C, the temperature in the area is at least 350 ° C ° C, advantageously at least 400 ° C and lower than 600 ° C, preferably lower than 580 ° C, and better than more than 550 ° C, the temperature in the zone is higher than the temperature of the zone that it immediately precedes him. Thus, in zone A2, the temperature T2 is greater than TI of the Al zone. These increasingly higher temperatures result in the transfer of the heated catalyst from the preceding zone, the introduction of the hot gas containing oxygen and the reaction exothermic combustion that develops, and the increasing severity of operating conditions. Preferably, in order to ensure the proper functioning of the combustion, increasingly hot gases are introduced at the level of the zones found in the catalyst circulation. Thus, the temperature T2 of the gas entering the second zone will advantageously be greater than that of the gas entering the first zone, and T3 will be greater than T2 (T3: temperature of the control zone). More precisely, a gas having a temperature at least substantially equal to that prevailing at the end of the combustion of the last combustion zone enters the FC zone. the oxygen content of the gas introduced is also increasingly greater at the level of the zones found by the catalyst, and the control zone corresponds to the largest oxygen content (the amount "greater than that of the gases that enter the highest levels.) After having suffered combustion, the catalyst has a reduced carbon content that reaches the oxychlorination zone (B) and passes through the conduits or legs. calcination (C) and leaves the chamber through the ducts (4) .. Figure 1 shows an oxychlorination zone and a calcination zone, several are possible.These zones are very advantageously of the axial type. On the one hand and oxychlorination, on the other hand, a plate or some other means of separation of the zones, allowing the passage of the catalyst, but not the gases, can be advantageously placed. freely from the calcination zone to the oxychlorination zone. In fact, in figure 1, there is only one catalyst bed for calcination and oxychlorination. The invention can employ different beds with gas and catalyst circulation. The gases coming from the combustion are evacuated by at least one duct (5) that opens into the treatment washing zone (6) to eliminate the "impurities, for example, washing." After pre-drying in a dryer (7) and in a compressor (8), the gases are divided into two flows.The first flow is recirculated through the conduit (9) to the combustion zones (A), after the addition of oxygen through the conduit (33) and eventually overheats , while the other part of the gas passes through the conduit 10. A dry oxygen content (dryer 13 preceded by a re-cooler) is added to the second gas flow in the conduit (10) by means of a conduit (11). attached to a compressor (12) that ensures a flow of air, for example, regulated for example thanks to a valve, depending on the percentage of oxygen required in the gas. A gas containing oxygen is obtained in the conduit (14). The gas is advantageously preheated in the exchanger (15), before passing inside an oven (16) (or any other heating means). According to the embodiment of figure 1, a part of this gas is fed directly to the oxychlorination zone through the conduit (17), while the other part will be fed to the calcination zone by the conduit (18). The injection of the gas into the oxychlorination zones is done before adding a controlled amount of water vapor through at least one duct (19) and a quantity of chlorinating agent through at least one duct (20). The ducts (17) and (18) reach the lower part of each of the axial zones so as to produce a gas-solid countercurrent. At the level of the duct (17), at least one baffle (24) for a good distribution of the gases is advantageously placed in the catalytic bed. The gas is evacuated from the oxychlorination zone by the conduit (21), it passes advantageously to the exchanger (15), before being routed to a washing zone (22). The washed gas can then be released into the atmosphere through the conduit (23) or more generally, evacuated outside the installation. Preferably, a conduit (18) attached to a conduit (14) is provided to provide the oxygen-containing gas in the calcination zone, preferably the conduit (18) is placed after the kiln (16). It will be noted that in the case of Figure 1, the gases introduced by the ducts (17) and (18) will have substantially the same oxygen content. The modality of figure 1 corresponds to an optimized proportion of the gases with the use of the gas coming from the combustion in the calcination zone. We can also obtain all the dry and reheated air directly in the calcination zone, that is, without fractionating the gas heated in the oven (16). This gas is thus, at least in part, sent to the oxychlorination zone. Another embodiment is shown in Figure 2, which is distinguished from that of Figure 1 by the equipment placed on the ducts (driers, ovens, exchangers ...). This figure is provided to illustrate the possibility of varying the arrangement of equipment and conduits within the framework of the invention. The conduit (5) for evacuating the gases coming from the combustion, which flows into a washing flask (6), is recognized. After washing, the gas is fractionated in a part that returns to the combustion zone through a duct (9), the equipment on this duct is not represented. The other part evacuated by the conduit (10) is added with compressed oxygen (air) (by the compressor (12)) provided by the conduit (11). The gas charged with oxygen passes to an exchanger (25), a dryer (26), an exchanger (15) and an oven (16). After reheating, the gas is divided into a flow that leaves by a conduit (17) to the oxychlorination zone with the addition of chlorinating agent through the conduit (19) and water through the conduit (20). The other flow goes through the conduit (18) to the calcination zone. The effluent that comes from the oxychlorination is evacuated through the conduit (21), passes to the exchanger (15), a * re-cooler (27), a washing flask (22) and is sent to the atmosphere through the conduit (23). It will be noted that the present modalities are made without recycling cycle of the oxychlorination gases. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims (19)

1. A regeneration process of a moving bed of a catalyst for production of aromatic hydrocarbons or reforming, the catalyst comprises a support, a noble metal and at least one halogen, the process is characterized in that it comprises a stage of combustion with the treatmof the catalyst in a moving bed, in at least two successive combustion zones, an oxychlorination stage, and a calcination stage, in which each combustion zone is separated from the "adjaccombustion zones, so as to allow the catalyst to pass and prevthe passage of the gases, in each zone of the combustion stage, at least one oxygen-containing gas is introduced and the gases produced are extracted from each zone, the severity of the operating conditions in each zone of the combustion stage, increases with the direction of the catalyst circulation, - at least one chlorinating agis introduced for the oxychlorination stage, at least one gas which e contains oxygen, and water, in such a way that the molar ratio H20 / HC1 is from 1 to 50, the oxychlorination stage is carried out in the presence of an oxychlorination gas containing less than 21% oxygen and at least 50 ppm in chlorine weight (calculated as HCl), and at a temperature of 350-600 ° C.

2. The process according to claim 1, characterized in that the gas extracted from a combustion zone is sat least in part to the next zone (in the direction of the catalyst circulation), with an optional complemof oxygen.

3. The process according to one of claims 1 or 2, characterized in that the gas extracted "from a combustion zone is sin its rety to the next zone, with an optional supply of oxygen.

4. The method according to one of the preceding claims, characterized in that the combustion stage is completed in a last so-called control zone of the end of combustion, in which the oxygen consumption is approximately less than 10% of the oxygen ring the combustion. said area.

5. The method according to one of the preceding claims, characterized in that the gases coming from the combustion stage are re-cooled, treated to eliminate the impurities, dried, compressed and then divided into two flows, the first flow is, after being added with oxygen and evally reheated, sto the first combustion zone, the second flow is, after being added with oxygen, water and chlorination ag and then heated, sto the oxychlorination stage, the gases coming from the oxychlorination are treat and evacuate outside the facility.

6. The method according to claim 5, characterized in that it comprises a combustion stage with the treatmof the catalyst in a first * combustion zone, then a second combustion zone, in which the zones are separated so as to pass through the catalyst , and prevthe passage of gases, the second combustion zone comprises in its lower part, a control zone for the end of combustion, and the gas extracted from the first combustion zone is sin its rety to the second combustion zone. combustion, after being added with oxygen, the gas coming from the second combustion zone is re-cooled, treated to eliminate the impurities, purged, dried, compressed and then separated into two flows, the first flow is introduced, then to be added with oxygens, in the first combustion zone, and after the eval reheating, in the control zone; the second flow is added with a dry gas containing superheated oxygen, and is sto the oxychlorination zone, after the addition of water and a chlorinating ag

7. The process according to claim 6, characterized in that the first flow is separated into two fractions, one is introduced after adding with oxygen, to the first combustion zone, the other is added with oxygen, reheated and introduced into the zone. of control .

8. The process according to claim 6, characterized in that the first flow is separated into two fractions, each is added with oxygen and is reheated before introduction, one in the first combustion zone, and the other in the zone of combustion. control.

9. The method according to one of claims 1 to 4, characterized in that the gases coming from the combustion stage are re-cooled, treated to remove the impurities, dried, compressed and then divided into two flows, the first flow is after to be added with oxygen and eventually reheated, sent to the first combustion zone, the second flow is, after being added with oxygen, water and chlorinating agent, and then heated, sent to the oxychlorination stage, the gases coming from the oxychlorination are treated and evacuated outside the installation.

10. The process according to one of claims 5 to 8, characterized in that the second superheated flow is separated into two fractions, one is sent to the oxychlorination zone, after the addition of water and chlorination agent, the other is sent to the calcination zone.

11. The method according to one of claims 5 to 9, characterized in that the two fractions that come from the first flow are reheated.

12. The method according to one of claims 5 to 9, characterized in that the fraction of the first stream is reheated before being introduced into the control zone.

13. The method according to the preceding claims, characterized in that for each combustion or control zone, the oxygen content of the gas entering is between 0.01-2%, the temperature of the gas entering is between 350-600 ° C, the residence time of the catalyst in a zone is between 5 min-3h and the PPH is between 1-50 h'1 and the severity of the operating conditions are obtained by increasing the temperature and / or the content of oxygen from the entering gas.

14. The method according to one of the preceding claims, characterized in that the temperature is substantially constant in the control area.

15. A method according to one of the preceding claims, characterized in that the calcination step * takes place in the presence of a gas with a content of at most 21% oxygen, and less than 1% water.

16. An installation for the regeneration of reforming catalyst or the reduction of aromatics comprising a support, at least one noble metal and at least one halogen, at least one inlet duct and one outlet duct (4) of the chamber catalyst, said catalyst in the form of a moving bed passing successively the combustion, oxychlorination and calcination zones, the chamber is characterized in that it comprises: at least two radial combustion zones (Al, A2), arranged in series, and between the combustion zones are placed separation means that allow the passage of the catalyst between said areas in the conduits for this purpose, but that prevent the passage of gases between these areas, - an area (FC) control end of combustion, located at the bottom of the last combustion zone, at least one conduit for introducing the oxygen-containing gas into the first combustion zone, at least one conduit for the evacuation of a gas from a combustion zone and for its introduction into the next combustion zone *, at least one duct for the introduction of the oxygen-containing gas into the control zone, at least one duct for the evacuation of the gases that come from the combustion stage outside the chamber, said duct is located before the oxychlorination zone, the chamber comprises at least one means for the re-cooling of said gases, at least one means for treating said gases to eliminate the impurities, at least one means for drying the gases, and at least one means for its compression, at least one conduit for evacuating a part of the gases that come from the combustion, compressed and gathered in the conduits, at least one conduit for evacuate the other part of the gases that come from combustion, compressed in said duct and placed in at least one gas heating means, and said duct is joined to at least one duct carrying a part of at least said gases to the oxychlorination zone, said conduit is joined to at least one conduit for the introduction of water and at least one conduit for the introduction of a chlorinating agent, - at least one conduit for the introduction of a gas containing oxygen in the zone of calcining, at least one conduit for evacuating the gases coming from the oxychlorination zone that have at least one means for the treatment of said gases before their evacuation outside the installation.

17. The chamber according to claim 16, characterized in that the duct comprises at least one means for heating the gas brought to the control area.

18. The chamber according to one of claims 16 or 17, characterized in that at least one means of cooling the gas is placed on each conduit.

19. The chamber according to claim 16, characterized in that the duct, comprises at least one means of re-cooling, followed by at least one dryer, after at least one compression means.