MXPA99005370A - Process and apparatus to put in contact reactives with a catalyst bed which moves intermittently while controlling the reaction temperatures - Google Patents

Abstract

Proceso y aparato para poner en contacto los reactivos con un catalizador particulado mientras se ponen en contacto los reactivos y el catalizador particulado con un medio de intercambio de calor y mientras se extrae y se reemplaza el catalizador particulado mediante una operación que restringe secuencialmente el flujo de reactivos moviendo al mismo tiempo el catalizador a través de los bloques de reacción en los cuales el flujo de reactivos ha sido restringido. La invención permite un cambio de catalizador en un arreglo de reactor de tipo canal que normalmente restringiría el flujo del catalizador durante la operación y permite el movimiento del catalizador a través de un reactor de intercambio de calor que tiene canales de reactivos y de intercambio de calor, permitiendo con ello el control de la actividad del catalizador, asícomo de las temperaturas de reacción.

Description

"PROCESS AND APPARATUS TO CONTACT REAGENTS WITH A CATALYTIC BED THAT MOVES INTERMITTENTLY WHILE CONTROLLING THE REACTION TEMPERATURES "FIELD This invention relates to chemical reactors for the catalytic conversion of a reaction fluid while replacing the catalyst and indirectly exchanges heat with a heat exchange fluid thereby controlling at the same time the reaction temperatures and the catalyst activity BACKGROUND In the petrochemical and chemical industries, the processes employ reactors in which chemical reactions are carried out in the components of one or more reaction fluids in contact with a catalyst under certain temperature and pressure conditions. The reactions generate or absorb heat at several points and are therefore exothermic or endothermic.The effects of heating or cooling associated with exothermic or endothermic reactions can affect the operation of the reaction zone in a positive or negative way. They can include and other things: little elaboration of produsto, deactivation of the catalyst, production of unwanted derivatives and, in extreme cases, damage to the reaction vessel and associated pipeline. More generally, the undesired effects associated with changes in temperature will reduce the selectivity or processing of products from the reaction zone. One solution to the problem has been the indirect heating of reagents and / or catalysts within a reaction zone with a heating or cooling medium. Most well-known catalytic reactors of this type are tubular arrangements having fixed or mobile catalyst beds. The geometry of tubular reactors poses design limitations that require large reactors or limit overall performance. Indirect heat exchange has also been performed using thin plates to define alternating channels that retain the catalyst and reagents in a series of channels and a heat transfer fluid in alternate channels to indirectly heat or cool the reagents and catalysts. The heat exchange plates in these indirect heat exchange reactors can be flat or curved and can have surface variations as grooves to increase heat transfer between the heat transfer fluids and the reactants and catalysts. Although thin plates of heat transfer can, to a certain extent, compensate for changes in temperature induced by the heat of reaction, not all indirect heat transfer arrangements are able to offer full control of temperature It will benefit many processes by maintaining a profile of the desired temperature through a reaction zone. Many hydrocarbon conversion processes will operate more conveniently maintaining a temperature profile that differs from the profile created by the heat of reaction. In many reactions, the most beneficial temperature profile will be obtained by substantially isothermal conditions. In some cases, a temperature profile directionally opposite to the temperature changes associated with the heat of reaction will provide the most beneficial conditions. An example of this case is in the dehydrogenation reactions where the selectivity and conversion of the endothermic process is improved by having an ascending temperature profile or inverse temperature gradient across the reaction zone. In US-A-5, 525, 311 a specific arrangement can be found for heat transfer and reagent channels that offers more complete control. Most catalysts for the hydrocarbon reaction are susceptible to deactivation over time. Deactivation will generally occur due to an accumulation of deposits that cause deactivation by blocking active pore sites or catalytic sites on the catalyst surface. When the accumulation of coke deposits causes deactivation, the reconditioning of the catalyst to eliminate the coke deposits restores the activity of the catalyst. The coke is normally removed from the catalyst by contacting the catalyst containing high temperature coke with an oxygen containing gas to burn or eliminate the coke in a regeneration process. The regeneration process can be carried out at the site or the catalyst can be taken out of a vessel in which the conversion of hydrocarbons is carried out and transported to a separate regeneration zone for the removal of the coke. The arrangements for continuously or semicontinuously removing catalyst particles from a bed in a reaction zone for the removal of coke in a regeneration zone are well known. US-A-3, 652, 231 describes a process of continuous regeneration of catalysts which is used in conjunction with the catalytic conversion of hydrocarbons. In the case of the reaction zone, the catalyst is transferred under gravity flow by removing the catalyst from the bottom of the reaction zone and adding catalyst to the top. A phenomenon known as "clamping" inhibits the transfer of the catalyst in many reactor arrays. "Clamping" is the phenomenon where the flow of reagent gas at sufficient velocity can block the downward movement of the catalyst. "Clamping" is a function of the velocity of the gas and the physical characteristics of the flow channel in which the flowing gaseous reactants have contact with the catalyst. When the gas flows through the channels that retain the catalyst, the gas attaches to the catalyst particles and causes intergranular friction between the particles. When the vertical component of the friction forces between the particles exceeds the force of gravity in the particles, the particles are "clamped". When the length of the flow path of the gas through the catalyst particles becomes longer, the forces in the particles increase progressively from the outlet to the entrance of the flow channel. In addition, when the catalyst flow channel becomes more limited, the gravity flow of the catalyst particles becomes more clogged. Consequently, as the size of the flow channel becomes more limited, the wall effects are increasingly added to the vertical holding force in the catalyst particles. As a result, narrow flow channels have a greater susceptibility to "clamping" and can not normally provide continuous circulation of catalysts. In the case of reactors that provide indirect heat exchange, the reactor arrangement exacerbates the problem of "holding" the catalysts. Increasing the number of channels decreasing in size facilitates heat transfer by increasing the surface area between the heat exchange fluid and the catalyst. In addition, heat transfer is further facilitated by irregularities in the surface of the plate that create turbulence and reduce the film factors that interfere with heat exchange. However, the irregularities in the plates that define the channels also interfere with the movement of the catalyst and promote a greater tendency for the catalyst to "set". Therefore, methods and reactor arrays are proposed to use a channel type reactor that facilitates heat exchange and catalyst circulation while the reactor is still in operation. SUMMARY Accordingly, an object of this invention is to provide a process for contacting reagents with a catalyst bed in a reaction zone while providing indirect heat exchange with a heat exchange fluid and running circulation of the catalyst through of the reaction zone. Another objective of this invention is to provide a reactor apparatus for the indirect heat exchange of a reagent stream and the contact of the reagent stream with a catalyst bed while allowing the running circulation of the catalyst.

This invention uses a sequential gas flow reduction or cessation, to periodically remove and / or replace the catalyst from the selected reagent channels in a single reaction zone so that continuous circulation can be effected in the reaction zone while maintaining the passage of the reactants through the catalyst and while indirectly exchanging heat between the reactants and a heat exchange medium. The subdivision of the reaction zone into a multiplicity of reaction blocks provides multiple banks of reagent channels for selective reduction or cessation of flow during the transfer of catalysts. The reaction blocks define alternating channel corridors. The corridors of channels extend vertically and horizontally. The catalyst enters the reagent aisles and is continuously or semi-continuously removed from the bottom of the aisle to effect catalyst circulation. The reagents flow radially through the reagent passages for contact with the catalyst. The plates that define the corridors provide a heat transfer surface for a heat transfer fluid that passes through the heat transfer channels. The removal and / or addition of reagents to the reaction blocks is selectively controlled so that the flow of reagents to one or more reaction blocks is interrupted or restricted while the flow of reagents continues in the remaining reaction blocks. The restriction or interruption of the flow allows the catalyst to fall under gravity flow of the selected reaction zones. The classification of the flow restriction of reagents and the removal of the catalyst can be carried out in a manner that suits the particular process. The cycle of reagent flow reduction and removal of the catalyst particles can proceed continuously with the sequential removal of the catalyst from each reaction block in a regular interval. Alternatively, the operation of the process may continue until a predetermined degree of deactivation results. At that time, a classification of reagent flow restriction can be used to establish a cycle that sequentially replaces the catalyst in each reaction zone until a desired degree of activity is re-established. A combination of catalyst replacement and indirect heat exchange with a heat transfer fluid can also provide a reaction advantage for processes using this invention. This combination can provide an isosinetic recess reaction within the reaction blocks. When the catalyst is replaced by increases in the reaction blocks, the more deactivated catalyst is removed from the bottom while the more active catalyst enters the upper part of the reaction block.

This periodic replacement thereby provides a continuous activity gradient along the length of the aatalyst lesho in each reaction block. The decrease in activity can be compensated for by an increase in the reaction temperature. In the case of an endothermic reassum where a vent fluid enters the heat transfer channels, the fluid can enter the reassessment block in a flow direction that compensates for the loss of activity in the sachallizer. By passing the heat exchange fluid from the bottom of the reactive block to the upper part of the reaction block, the higher temperatures are maintained in the lower part where the most deactivated catalyst has sontaste are the reastives. Advancing upwards through the reassuring block, the reagent salting cools the heating medium thereby causing a relatively low temperature for the reagents in the upper part of the reaction block which contains the most active catalyst. Adaptation of replacement of catalysts, the temperature of the heating medium and the heat exchange through the reagent channels and heat exchange can be arranged to provide an isokinetic operasion through the reaction zone. This isozyme operation can result in a more uniform effluent of the product and the more efficient utilization of the reaction volume in each reaction block. The isokinetic conditions can be maintained exothermic reactions, as well as with endothermic reactions. In the exothermic reactions, the cooling medium must enter the upper part of the salinity exchange channels to maintain a parallel flow are the satallizer so that the maximum cooling is provided in the most astute satalizer region. Accordingly, in one embodiment, this invention is a process for counteracting the reagents with the catalyst in a channel reactor and indirectly reconciling the reagents with a heat transfer fluid that allows intermittent movement of the catalyst through the catalyst. a catalyst bed. In the process, the catalyst particles are retained in a plurality of reactive blocks. Each reaction block has a plurality of reaction channels extended vertically and horizontally and heat exchange channels. A stream of reagents passes to at least one of the reagent blocks and contacts the catalyst with the reagent stream. A soruent of product is recovered from the reagent channels. A heat exchange fluid passes through the heat exchange channels and at least one parsial restriction of the flow of the reagent stream to a selected reaction block is effected intermittently to transfer the particles of the sataylator into the block of selected reassessment by removing the catalyst particles from the bottom and adding them to the top of the reactive block. The flow of the retentate soruent is stabilized again in the reastive block after the adsorption of the satative to it. In another embodiment, this invention is an arrangement of the channel reastor to contact the reagents with a particulate catalyst, indirectly exchanging the reagents with a heat transfer fluid and replacing the catalyst particles in the stream. The array includes a plurality of reactive blocks comprised of parallel plasmas extending vertically and horizontally to define salinity transfer channels and reagent channels in each reagent block. A means is provided for passing a retentate stream through the reagent channels and selectively restricting the flow of the reagent stream through the seals of reagent seals. A means is also provided for passing and adding catalyst particles to the upper part and removing them from the bottom of each reactive block. The reagent channels also work in cooperasión are a means to pass a fluid of heat exchange through the channels of intersambio of salor of sada block of reassión.

In another realization, this invention is a reastor to put in sontasto the reastives are a split satallizer while indirectly intermeshing the reactants with a heat exchange fluid and replacing the catalyst particles in the stream. The apparatus contains a refill container that houses a plurality of reassignment blocks. Each reaction block comprises a plurality of parallel plates extending vertically and horizontally to define the heat transfer channels and reagent channels in each reaction block. The reaction vessel defines a reagent inlet to pass a stream of reagents to the reagent channels. At least two pipes receive fluid from the reagent channels. Each pipe is in communisation with a valve to regulate the flow or fluid of the reagent channels and is communicated with less than the total number of reagent sanales. A catalyst distributor at the top of each reagent block and a catalyst manifold at the bottom of each reagent block operates in conjunction with a means to selectively control the addition of catalyst particles to each block of reagents and removal of the catalyst. the same ones of each reagent block. A means for passing a heat exchange fluid through the heat exchange channels in each reaction block is also provided.

In the following detailed description of the invention, realizations, arrangements and additional details of this invention are disclosed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical section of a reactor arranged in accordance with this invention. FIG. 2 is a section taken along line 2-2 of FIG. 1. FIG. 3 is a schematic representation of a reaction block and the flow of catalyst, reagents and heat exchange medium therethrough. FIG. 4 is a cross section of the reaction block taken along line 4-4 of FIG. 3. FIG. 5 is a schematic diagram of a system for removing the catalyst. FIG. 6 shows a cross section of a reactor containing reactive blocks similar to those shown in FIGS. 1-4. DETAILED DESCRIPTION The process can be useful in a wide variety of catalytic reactions using heterogeneous catalysts. Proper arrangements of the reaction zone will employ a moving catalyst bed as opposed to a fluidized catalyst bed. This invention applies more beneficially to catalytic conversion processes that have high heats of reaction. Typical reactions of this type are hydrocarbon conversion reassessments that include: aromatization of hydrocarbons, conversion of hydrocarbons, dehydrogenation of hydrocarbons and alkylation of hydrocarbons. These hydrocarbon conversion processes, to which this invention is adapted, include: paraffin satalitide dehydrogenase, deaeration of naphtha supply sorbent, light hydrocarbon aromatization and alkylation of aromatic hydrocarbons. The reaction zones for the process of this invention can bring the reagents back into equilibrium with the heat exchange fluid in any relative direction. In this way, the flow channels and inlets and outlets of the replenishment zones can be designed for parallel, countercurrent, or cross flow of reagent and heat exchange fluid. Preferred process arrangements for practicing this invention will pass reagents in the cross flow to the heat exchange fluid. The cross-flow of reagents is generally preferred to minimize the pressure flow as a result of the flow of reastives through the reastor. For this reason, a flow-through arrangement can be used to provide the reactants with a shorter flow path through the re-entry zone. The shorter flow path reduces the overall pressure drop of the reagents as they pass through the catalyst particles retained in the reactor. Lower pressure drops can have double advantage in the processing of many reagent streams. The increased resistance to fluensia, it is to say, the pressure output, can raise the general pressure of operation of a process. In many cases, the performance or selestivity of the product is favored by the lower operating pressure so that the decrease in pressure drop will also provide a higher yield of the desired products. In addition, the higher pressure drop raises the overall utility and operating cost of a process. It is also not necessary for the practice of this invention that every sandal of reastives be alternated is a sanal of intersambio of salor. Possible configurations of the reaction section can put two or more heat exchange channels between each reagent channel to reduce the pressure drop on the side of the heat exchange medium. When used for this purpose, a plate separating the inter-heat heat sanders may contain perforations. The type and details of the reactor arrangement contemplated in the practice of this invention are best captured by reference to the drawings. FIG. 1 is a schematic representation of a section of the catalytic reactor 10 designed to probe a satastitic reassignment in a reagent fluid using indirect heat exchange with a heat transfer fluid at the same time to maintain favorable reaction temperatures as the reagent fluid flows through the reaction section. The reactor section contains a means for sequentially restricting the flow of the porsions of the reactor section to allow replacement of the catalyst in the reactor section. The reactor contains multiple reactive blocks. The reactor carries out the sackitisation reaction of a horizontally flowing reastive fluid under temperature sonsions sonrated by indigestible sontaste is a vertical heat transfer fluid allowing at the same time the movement of the catalyst through the blocks of reassurance The session of the retainer 10 assumes a reaction vessel 12 having a sirsular cross-section. The reaction vessel 12 has a "frust" conical head 14 that supports a catalyst vessel 16. A hemispherical head 18 closes the bottom of the reaction vessel 12 and defines an inlet 20 for a stream of reagents. The reagents flow through the inlet 20 to a line 22 that distributes the reagents to the reagent inlet tubes 24. As shown in FIG. 2, the retentate inlet tubes 24 supply the reagent sorptive to the distribution spas 26. The reagents flow horizontally through the reaction blocks 28 through the vertically defined reagent flow channels defined therein. A recovery space 30 collects reaction products from the reagent channels. A cholestor tube 32 removes the reuse products from the collection space 30 and transports them out of the reaction vessel through a line 34 at a rate regulated by a control valve 36. In the arrangement of FIGS. 1 and 2, each retentate inlet tube 24 supplies reagents to two reaction blocks 28 while each outlet tube 32 removes reaction products from the two reaction blocks 28. The deviation of the reagent inlet tubes 24 to the outlet tubes 32 causes each outlet tube 32 to remove reagents supplied by two different reagent inlet tubes 24. Therefore, when the control valve 36 restricts or stops the flow of an outlet tube 32, the remaining flow of the reagent inlet tubes goes to remaining open outlet tubes 32. In this way, the inlet pipe remains active as long as the catalyst is taken out of a reaction block. The reagent stream has contact with a particulate catalyst in each of the re-entry blocks. The catalyst will be present as discrete particles generally in a size range of 2 to 15 mm in diameter. The particles can have any shape, but normally they will include spheres or cylinders. The sappanizer filler 16 retains the satallizer for passage to the reagent channels of the reaction blocks 28. The catalyst enters the upper part of the catalyst vessel 16 through a catalyst charging nozzle 38. A distributor tube of Optional gas 40 can distribute a gas stream from a nozzle 42 to the vessel 16. The gas added to the catalyst vessel 16 can be a reduction gas for further treatment of the catalyst or a purge gas for evasion of undesirable gas sorbent which can be entering the catalyst vessel 16 into the empty space of the catalyst when it enters the vessel. A cholester screen 44 defines an annular space 46 from which the purge gas or others are removed from the catalyst vessel 16 through a nozzle 48. The catalyst flows from the catalyst vessel 16 through the catalyst transfer tubes 50 to a diffuser 52 that distributes the catalyst through the upper part of the reaction channels in the reaction block. A catalyst collector 54 at the bottom of each reaction block 28 extracts the catalyst through the catalyst extraction nozzles 55 in a manner further described herein. The heat exchange fluid enters the process through a nozzle 56 that supplies the salinity exchange fluid to an inlet solder tube 58. The distribution tubes 60 supply the heat exchange fluid to the heat exchange line. 62 at the bottom of each reactive block 28. The salor inter- mediate fluid flows vertisally into the heat exchange channels in the reassessing block in a solestora 64 pipe in the upper part of the salso inter- assembly 28. Figure 66 supplies the saline intermixing fluid to a solar water pipe 68, the sual extracts the saline intermixing fluid from the reuse basin 16 through a nozzle 70. The arrangement and operation of the reassessment blocks is shown more clearly by a schematic representation in FIGS. 3 and 4. Each reaction block 28 comprises a plurality of parallel plates 72 as shown in FIG. 4. The plasmas adesudas for this invention will show plasas that allow a high speed of heat transfer. Thin plates are preferred and generally have a thickness of 1 to 2 mm. The plates are usually composed of ferrous and non-ferrous alloys such as stainless steel. Each plate 72 may be smooth, but preferably has grooves that are insined to the flow of reagents and the heat exchange fluid. The plates can be formed in curves or other configurations, but flat plates are generally preferred for stacking purposes. The grooved plates can be stacked directly one after the other with space between the grooves defining alternating reagent channels 73 and heat exchange channels 74. When the plates 72 contain inclined grooves, the plates can be stacked one after the other to define the channels of heat intergroup and reagent flow as the area between the grooves. Preferably, the pattern of the grooves will be inverted between adjacent plates so that a spine pattern on the faces of the plates with opposite grooves will extend in opposite directions and the faces of the opposing plates can be brought into contact with each other to form the flow channels and provide structural support to the plate sections. The catalyst particles 75 fill the reagent flow channels 73. The sides 76 of the reagent flow channel 73 are closed to the catalyst flow by a permeable closure that still allows the flow of reagents in the direction indicated by the arrows "A " The sides 77 of the salt interspacing channels 74 have a fluid-impermeable seal which maintains the heat inter-assembly fluid over the length of the channel 74. The upper part of the salt interbody sanal is serrated to prevent entry of the satalizer. As shown in the reaction block of FIG. 3, the heat exchange fluid flows downwards as indicated by the arrows "B" so that the reassignment block defines a specific system for the flows "A" and "B" where the stream of reastives "A" "and the interstage fluid of salor" B "flow in cross directions and through alternating channels formed by adjacent plates 72. As previously mentioned, catalyst particles 75 flow to the upper part of reagent channel 73 through the diffuser 52. The diffuser 52 may contain internal screens or grooves 78 to distribute the catalyst evenly across the top of the reagent channels. Similarly, the collector 54 at the bottom of the reagent channel 73 collects the catalyst particle 75 and may contain screens or grooves 80. The screens or grooves in the diffuser and collector promote uniform replacement of the catalyst throughout the entire horizontal length of each reagent channel 73. Each reaction block includes in its upper part an inlet for receiving the saline intermixing fluid in the circulation system "B". The entrance can be of a single opening. FIGS. 3 and 4 show the piping 64 and 62 for distributing and collecting the bottom and top salor interpartial fluid, respectively, of the replenishment block 28. The piping 64 and 62 are communized are the heat exchange channels 74 to through the openings in the sides 77 that are in the upper part and the bottom in the opposite sides of the reactive block. The pipes provide a distribution area on the sides of the reassignment block. In the distribution area subverted by pipelines 64 and 62, the sides 76 of the reagent sanales are closed to prevent entry of the saline exchange fluid into the reagent channels. The system for removing the catalyst from each of the reactive blocks is shown schematically in FIG. 5. As previously explained in the arrangement of FIGS. 1-4, each reagent tube controls the extraction of products from an adjacent pair of reaction blocks. The control of the retentate flow of the reassignment blocks 28 'is shown schematically by the valve 36' which regulates the flow to an input line 34 'of the reagent production line 32'. The satallizer is removed from the reassignment blocks 28 'by the opening of the sonol valves 80' the suals distribute the catalyst through the lines 82 to a drive vessel of the sataylator 85. Preferably, the drive vessel 85 is subdivided into sections that receive the catalyst from one of the reaction blocks. The volume of each compartment in the delivery vessel 85 can be predetermined to match the amount of catalyst extracted from each reaction block during each extraction cycle. The catalyst collector 54 'can serve as a containment zone for the satallizer volume that will be extracted in each extrasion tank. A continuous purge of line 84 can be added to evacuate reagents from the empty volume of the catalyst while being retained in cholester 54 '. The compartmentation of the catalyst particles extracted from the reaction block facilitates the monitoring of the extraction of the catalyst to verify whether the reassuring block is supplying the satallizer during the extrasion cycle. The filling of each compartment can be monitored by measuring the level in the compartment or by monitoring the temperature of the compartment to see if the outgoing satallizer has entered. The lines 83 distribute the catalyst to the drive vessel 85 of other reactive blocks (not shown).

The catalyst passes from the delivery vessel 85 to a fixing hopper 86. The satallizer enters the fixing hopper through a line 88. Line 88 is a series of valves 90, 92 and 94. The combination of valves 90 and 92 provide a gas tight seal along line 88. Valve 90 closes the line to the catalyst flow and is designed to stop the flow of the catalyst without damage to the valve seals or seats, but does not provide a seal gas tight. Once the catalyst flow has stopped, the catalyst falls below the level of the valve 92 which has gas tight seals, but is susceptible to damage if the catalyst is present. The valve 94 also provides a gas-tight seal and can isolate the fixing hopper from the remainder of the line 88 for the purpose of purging the remainder of the line 88 in the delivery vessel 85 by the addition of nitrogen through a line 96 at a speed regulated by a control valve 98. The catalyst passes out of the fixing hopper 86 through a line 100 which again contains a series of three valves: 102, 104 and 106. The series of valves in the line 100 operates in the same manner as the valves on line 88 with valve 102 providing a catalyst seal while valves 104 and 106 provide a gas seal once the catalyst is clear. A line 108 provides a nitrogen purge to isolate the fixation hopper from the atmosphere below the valve 106. The fixation hopper can also receive a continuous inert purge from line 109 to evacuate oxygen from the fixation hopper during the catalyst discharge. The purge gases and the purged gases exit the fixing hopper through a line 110 '. The fixing hopper 86 is adjusted to store the catalyst until it is removed from the process for regeneration. The attachment hopper 86 may be used to transfer the transfer sap to a continuous catalyst regeneration system which operates in conjunction with the reactor or may retain the catalyst for drum charging and off-site regeneration or replacement. When the catalyst of the fixing hopper is discharged to drums, preferably the fixing hopper will have sufficient volume to contain the volume of the catalyst contained in the reactive blocks. This allows a complete sambium of the catalyst of the reaction blocks before the discharge of the fixing hopper is necessary. When the fixing hopper is depleted, oxygen from the atmosphere will flow back to the fixing hopper. The purge system provides a means to eliminate this oxygen which, in most reation systems, oxygen must be kept out of the reaction zones. The process can be operated in a variety of ways. The sensal element for the dessarga or serge of the catalyst of the narrow sanalos formed by the blocks of reuptake is the flow restriction towards or outside the reactive blocks. The flow to the reaction blocks or outside thereof can be arranged to control multiple reaction blocks at a time as shown in the embodiment of the invention in FIGS. 1-5. Alternatively, the flow of reagents to each reaction block or products outside each reaction block can be controlled individually. An arrangement for the individual flow of reagents into or out of the reassessment block is shown in FIG. 6. FIG. 6 shows a horizontal transverse sessión of a reastor that are reaction blocks -similar to those shown in FIGS. 1-4. FIG. 6 differs from FIGS. 1-4 in which the reactive blocks 110 are arranged in a sirsunferensial manner in a polygonal colossal around a central spas 112 that can serve as a distributor or as a cholestor. A screen 116 surrounds the exterior 114 Sada Resetting Block 110. Screen 116 again defines a space on the outside of each Reaction Block 110 that can serve as a solestor or distributor. The individual tube openings 118 communicate with the outer space 117 enclosed by each screen 116. Proper valveing in the outlet pipe 118 may selectively restrict or stop the flow through each individual reset block. All the reaction blocks may be surrounded again by a reaction vessel 120 to provide pressure containment for the reassessment. In a method of operation, the reaction section shown in FIGS. 1-5 will operate only with the periodic replacement of the satallizer. During most of the operation, the catalyst will remain in the reaction blocks and the reagent flow or product effluent slasification will only occur during a transitory period while a replacement satalogy cision occurs in the reassessment blocks. Therefore, the reactants will enter the reactor vessel through the pipe 22 and will be removed through the outlet pipe 32 until a predetermined time period or degree of stripping of the catalyst is observed. Once the colossation of a satallizer is desired, PLO will start an extrasion- catalyst classification of the reaction block pairs. The sequence begins by closing the valve 36 to stop the flow of reagents through two of the reactive blocks. Once the flow of reastives has stopped, the predetermined sanctity of The satallizer is extracted from the two blocks of reassignment from which the flow of reactants has stopped selectively. For periodic replacement of the satallizer, a large volume of satallizer will usually be removed from each reaction block. Preferably, one volume is deleted of catalyst equal to about 25% of the total volume in the reactor block. When the satallizer is removed from the bottom of the reaction block, the replacement catalyst flows from the catalyst vessel 16 to replace an amount of catalyst equal to that extracted.

After replacement of the catalyst, the control valve 36 in the outlet tube 32 is opened to re-establish the flow of reactants through the reaction block that has just received the fresh catalyst. The sequence then continues with the closing of the valve of the outlet pipe for the next pair of reassuring blocks in order to stop the flow of the same. Once an equivalent volume of the satallizer has been inter-assembled again in the next pair of reaction blocks, the sequence continues until an equivalent volume of catalyst has been exchanged in all the reactive blocks. The replacement of the satallizer in this manner will not interrupt the process to a substansial degree. The somatic flow of reastives through the reastor can be maintained while sambiaating the satallizer in the selected reaction blocks is only a moderate increase in the pressure output. The total flow of reagents can normally be maintained through the catalyst change process. In most processes, it is also not necessary to stop the flow of the heat exchange fluid through the reaction blocks while the flow of reactants is restricted or stopped for the change of the satallizer. For most processes, only a relatively small change in the temperature of the heating medium occurs when it flows through the interstitial channels of the salor. This temperature will generally be less than 12 ° C (20 ° F). As a result, the overheating of the reaction blocks during the process of changing the catalyst is not likely to occur despite the restriction or elimination of reagents. In most cases, the reagent flow will be essentially stopped during the catalyst change process. However, it may still be advisable to maintain a minimum sanctity of flow through the zone of reassurance to avoid a static snorting in the spasm of reassurance. The need to maintain a flow of reagents or to reduce the flow of the heating medium during the change of the catalyst will depend on the particular process in which the invention is practiced. Satalitisa sonversion is a well-stable hydrocarbon conversion process used in the petroleum refining industry to improve the output of the hydrocarbon supplies osmosis, the primary product of the conversion being motor gasoline. The art of catalytic conversion is well known and does not require a broad description in the present. Briefly, in the catalytic conversion, a mixed supply is a resisting soruent, igniting hydrogen and contacting the catalyst in a reaction zone. The usual supply for the satalitisa conversion is an oil phosphate sonoside with naphtha and having an iniial boiling point of 80 ° C (180 ° F) and a final boiling point of 205 ° C (400 ° F). The catalytic conversion process is particularly applicable to the treatment of direct distillation gasoline constituted of relatively large concentrations of naphthenic hydrocarbons and paraffinisos de sadena substantially subtract, the suals are subject to aromatization through dehydrogenation and / or cyclization reactions. The conversion can be defined as the total efesto produced by the dehydrogeneration of sislohexanes and the dehydroisomerization of alkylsispentanes to produce aromatise substances, the dehydrogeneration of paraffins to produce olefins, the dehydrosi fi cation of paraffins and defines to produce aromatic substances, the isomerization of n-paraffins, the isomerization of alkylcycloparafines to produce cyclohexanes, the isomeization of substituted aromatic substances and the hydrodisintegration of paraffins. In US-A-4,119,526, US-A-4,409,095 and US-A-4, 440, 626 additional information on conversion processes can be shown. A reaction of the catalytic conversion is usually carried out in the presence of catalyst particles consisting of one or more noble metals of Group VIII (for example, platinum, iridium, rhodium, palladium) and a halogen is a porous carrier, is an oxide refractory inorganic Halogen is usually chlorine. Alumina is commonly a carrier. The preferred alumina materials are sonosides such as gamma alumina, eta and teta are gamma and eta alumina giving the best results. An important property related to the performance of the catalyst is the surface area of the carrier. Preferably, the carrier will have a surface area of 100 to 500 m / g. The particles are generally spherical and have a diameter of 1.5-3.1 mm (1/16 of an inch to 1/8 of an inch), although they can be as large as 6.35 mm (1/4 of an inch). A preferred diameter of catalyst particles is 3.1 mm (1/16 inch). During the course of a sonsion reassignment, the catalyst particles are deactivated as a result of mechanisms such as the deposition of coke in the particles; that is, after a period of time in use, the ability of the catalyst particles to promote the conversion reactions decreases to the point where the catalyst is no longer useful. The catalyst must be re-homed, or regenerated, before it can be used again in a conversion process. In the preferred form, the conversion operation employs a reaction zone with moving bed and regeneration zone. The present invention is applicable to these moving bed zones. In a mobile lesho operation, the fresh catalyst particles are supplied to a reaction zone by gravity. The catalyst is extracted from the bottom of the reactive zone and transported to a regeneration zone where a multi-step regeneration process is used to re-disassemble the satallizer in order to fully restore its reaction promotion ability. The catalyst flows by gravity through the various regeneration steps and is then extracted from the regeneration zone and proportioned to the reassessment zone. The catalytic conversion processes normally effect the repeated transfer of relatively small amounts of catalyst at closely spaced points in time. Therefore, while the movement of the catalyst is often referred to as continuous, it is actually semi-continuous. Catalytic dehydrogenation is another example of an endothermic process that uses in a convenient manner the process and apparatus of this invention. Briefly, in catalytic dehydrogenation, a supply is mixed in a recycle stream comprising hydrogen and contacted with the catalyst in a reactive zone. The supplies for the dehydrogenation satalitisa are usually oil frassiones somning paraffins that have 3 to 18 atoms of sarbon. Particulate supplies will usually contain light or heavy paraffins. For example, a usual supply for making heavy dehydrogenous products will yield paraffins having 10 or more sarbono atoms. The process of dehydrogenation satalitisa is in particular apisable to the treatment of hydrosarbon supplies by hydrosarburos substantially paraffinisos which are subject to dehydrogenation reactions to thereby form olefinic hydrocarbon compounds. A catalytic dehydrogenation reaction is usually carried out in the presence of catalyst particles consisting of one or more noble Group VIII metals (for example, platinum, iridium, rhodium, palladium) combined with a porous carrier, such as a refractory inorganic oxide. Alumina is again a commonly used carrier and the preferred alumina materials are again the same as those described for catalytic conversion. Generally, the particles of the satallizer have a slurry sonsension of between 0.5 and 3 per cent by weight. During the course of a dehydrogeneration reassumption, the catalyst particles are also deactivated as a result of the deposition of the coke and require regeneration similar to that described in conjunction with the sonification process; therefore, the dehydrogenase process will again use the reassessment zone as the mobile lesho of this invention. The dehydrogenation conditions include a temperature of 400 ° C to 900 ° C (752 ° to 1652 ° F), a pressure of 10 to 1013 kPa (0.01 to 10 atmospheres) and a time delay of liquid spasm (LHSV) of 0.1 to 100. hr "1. Generally, for normal paraffins, the lower the mole weight, the higher the temperature required for somatic conversions.The pressure in the dehydrogeneration zone is kept as low as possible, consistent with the limitations of the equipment, for Maximize chemical equilibrium advantages The preferred dehydrogenase properties of the process of this invention include a temperature of about 400 ° -700 ° C (752 ° to 1652 ° F), a pressure of 10 to 507 kPa (0.1 to 5 atmospheres) and a liquid space hourly rate of 0.1 to 100 hr-1. The effluent stream from the dehydrogenation zone will generally contain unconverted dehydrogenatable hydrocarbons, hydrogen and the products of dehydrogenation reactions. This effluent stream is normally cooled and passed to a hydrogen separation zone to separate a hydrogen-rich vapor phase from a liquid phase rich in hydrocarbons. Generally, the hydrocarbon-rich liquid phase is further separated by means of a suitable selective adsorbent, a selective solvent, a reassessment or selective reactions or by means of a suitable fractionation scheme. Dehydrogenatable hydrocarbons that are not converted are recovered and can be recycled to the dehydrogeneration zone. The products of the dehydrogenation reactions are recovered as final products or as intermediates in the preparation of other formulations.

The dehydrogenatable hydrosarburos can be admixed with a diluent gas before, while, or after being passed to the dehydrogenation zone. The diluent material may be hydrogen, steam, methane, carbon dioxide, nitrogen, argon and the like, or a mixture thereof. Hydrogen is the preferred diluent. Ordinarily, when a diluent gas is used as the diluent, it is used in sufficient quantities to ensure a molar ratio of diluent gas to hydrocarbons from 0.1 to 20, with the best results being obtained when the molar ratio is 0.5 to 10. The Hydrogen diluent passed to the dehydrogenase zone will normally be hydrogen resins separated from the effluent from the dehydrogenase zone in the hydrogen separation zone. The water, or a material the sual is decomposed into dehydrogenase conditions to form water, such as an alcohol, aldehyde, ether or ketone, can be added to the dehydrogenation zone. The water or water precursor may be added continuously or intermittently in an amount that provides, calculated on the basis of equivalent water, from 1 to 20,000 ppm by weight of the soruent of. Hydrosarbon supply. Addition of 1 to 10,000 ppm by weight of water gives better results by blending dehydrogenase paraffins having from 6 to 30 or more sarbonium atoms. In US-A-4,677,237; US-A-4, 880, 764 and US-A-5, 087, 792 can be found. Additional information is the operation of dehydrogenation catalysts, operating conditions and process arrangements. EXAMPLES The purpose of using the process and the reactor arrangement of this invention to change the catalyst and maintain the isokinetic condi tions was investigated in a process for the sonrosion of hydrocarbons for the dehydrogeneration of paraffins. This simulation predicted the results of the satalizer changing semicontinuously in a zone of dehydrogenase reactivation by periodically replacing the satalizer in 10% ingredients. The satallizer is a typical dehydrogenase satallizer that platinum suds on an alumina support. The astivity of the catalyst varied linearly in a gradual way from 100% in the upper part of the lesho to 55% in the bottom of the lesho. The proseso operated in a ratio of hydrogen to hydrocarbons of 2.9 with an LHSV of 31.5 m_1. The reation zone was maintained at an average pressure of 194 kPa (13.5 psig). The supply stream at a flow rate of 58.060 kg / hr (128,000 lbs / hour) entered the reactive zone and had a molar somposission as shown in Table 1. The supply short-circuit entered the reactor at a temperature of input of 432 ° C (810 ° F) and left at an average exit temperature of 479 ° C (895 ° C). The supply soruent was put in sontratum in a current flow with 794 mg / hr (1.75 million pounds / hour) of a heating medium having a density of 83.3 kg / m3 (5,198 lbs / ft3) and a heat sappiness of 0.705 kJ / kg (.303 BTUs / lb / ° F). The heating medium entered the process at a temperature of 560 ° C (932 ° F) and exited at an average exit temperature of 481 ° C (898 ° F). The conversion of the percentage by weight of the supply stream was 20.15% by weight with a selectivity by weight percentage of 85.7% of monoolefins, 4.7% of diolefins, 4% of aromatic substances and 4.2% of light terminals. TABLE 1

Claims (8)

1. CLAIMS 1. A process for stacking the reagents with a particulate catalyst in a sanal reastor while inductively stacking the reastives is a transferensia fluid of salor and intermittently moving the satallizer through a lesho formed satalizador by the reheat sanales, the process comprising: retaining the catalyst particles in a plurality of reactive blocks, each reactive block having a plurality of vertical and horizontally extended reation channels and heat exchange channels; passing a stream of reagents to at least one of the reactive blocks and contacting the catalyst are the retentate gas therein; passing a salor exchange fluid through the heat exchange channels; Intermittently carry out at least a partial restriction of the flow of the reactant stream to a selected reaction block and transfer the catalyst particles in the sequestered reactant block by removing the saproot particles from the bottom and adding them to the top of the block of selected recruitment; re-setting the flow of the reactant stream to the selected reaction block after the addition of the catalyst thereto; and recover a product stream from the reagent channels.
2. 2. The process of Claim 1 wherein the heat transfer fluid flows vertically through the heat exchange channels and the reagents flow horizontally through the reagent channels.
3. 3. The process of Claim 1 or 2 wherein the count of the reastives is the satallizer produces an endothermic reassumption and the saline intermixing fluid is a vent fluid that flows from the bottom to the top of the exchange channels of the former. hot.
4. 4. The process of Claims 1 or 2 wherein only a portion of the catalyst present in the selected reaction block is transferred from the reassignment block while the reagent flow is restricted.
5. 5. The process of Claim 3 wherein the reastives somengena dehydrogenables hydrosarburos and produsto somprende olefinas.
6. 6. The process of Claims 1 or 2 wherein the flow of the heat exchange fluid is maintained while the flow of the reagents is interrupted.
7. 7. A sanal reagent arrangement for contacting the reagents is a partislated satallizer, indirectly thermally exchanging the reactants with a heat transfer fluid and replacing the catalyst particles in the stream, the arrangement comprising: a plurality of Reaction blocks comprising a plurality of parallel plates extending vertically and horizontally and defining salinity transfer channels and reagent channels in each reaction block; means for passing a stream of reagents through the reagent channels and selectively restricting the flow of the reagent stream through a selected replenishment block; means for adding catalyst particles to the top and extracting the catalyst from the bottom of each reassessment block; and means for passing a heat exchange fluid through the salt interphase channel of the reassessment block.
8. 8. The arrangement of Claim 7 wherein the means to restrict the flow of the reastive includes a pipe to resoger the fluid flow of the sanitizers of reagents in each block of reuptake, an outlet defined by each pipe and a valve to regulate the flow of each exit.