BE630101A - - Google Patents

Description

       

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  The process of hydrocracking carburized hydrogens with a large-pore moldcular sieve, which contains a platinum group metal *.



   The present invention relates to the catalytic hydrocracking of hydrocarbons. It relates more particularly to a process in which the hydrocarbons are subjected to cracking.
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 quage in the presence of hydrogen and a crystalline adolithic molecular sieve with large pores, this diameter being uniform and between 6 and 15 A, a metal or a metallic compound of the platinum group being mixed with this molecular sieve,

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 or impregnating this molecular sieve or else serving as a support for the latter.

   Still more particularly, the present invention relates to the cracking of hydrocarbons in the presence of hydrogen and a large-diameter molecular sieve, which is supported by or mixed with a metal or a platinum group compound. metal or this compound, when, for example, platinum, palladium, rhodium, iridium, ruthenium or an analogous metal, the content of alkylated metal of the zeoinic support being less than 10% with respect to the weight of the support calculated as the alkali oxide.



   The cracking of hydrocarbons in the presence of hydrogen is a well-known operation in the refining of oils and numerous catalysts have been used or proposed for this purpose.



   In general, cracking finds its greatest utility with hydrocarbons boiling in the range of heavy naphtha and gas oils, although it can also be used for improvement, by conversion to gas oils and gas oils. in gasoline, products such as heavy gas oils and products with even higher boiling ranges. In general, first distillation naphtha and catalytically treated naphtha, gas oils, recycle oils and materials from conventional cracking operations which generally boil in gas and recycle oils can be hydrocracked. the boiling range of gas oils, and of aromatic alkyl hydrocarbons in general,

   as well as heavy first distillation naphtha and gas oils. The process is also advantageous for the dealkylation by hydrogenation of aromatic alkyl moieties to obtain aromatic alkyl hydrocarbons having a lower boiling range and fully dealkylated aromatic hydrocarbons.



   The hydrocracking process itself consists in passing the feed to be treated, mixed with hydrogen,

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 on the catalyst, if a catalyst is used in a fixed bed, or in contact with a moving bed or a fluidized bed of the solids of the catalyst, using appropriate conditions of temperature, flow rate, summer pressure, to obtain a conversion of the charge to be processed into products having lower boiling points, such as gasoline. At the same time, organic nitrogen and sulfur compounds, which are present in the feed, are largely transformed into ammonia and hydrogen sulfide, respectively.

   The conditions of the reaction are determined to a considerable degree by the nature of the feed to be treated, the activity of the catalyst and the nature of the final product desired.



   Prior art catalysts which have been used in this process have not been completely satisfactory for several reasons. It has been found that certain catalysts are particularly sensitive to the presence of impurities contained in the feed, in particular to the presence of organic nitrogen. Such catalysts include metals, oxides and sulfides of the iron group metals. These catalysts require frequent regenerations or the maintenance of reaction conditions which do not make it possible to obtain high yields of the desired product.

   Other catalysts, such as noble metals supported on conventional amorphous cracking catalysts, such as silica-alumina, silica-agnesia, silica-alumina-magnesia, and the like catalysts have not. showed as high activity as would have been desired, and they also need to be regenerated more often than desirable. Many catalysts also have high tendencies to coke, and in addition require high pressures. relatively high, which is expensive to obtain, as well as purification of the feed.



   The object of the present invention is to obtain tata-

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 Efficient and selective lysers for the hydrocracking of charges to be treated constituted by hydrocarbons in order to produce, with an excellent foundation, hydrocarbons having lower boiling points, gasoline and / or fuel oils.,
In accordance with the present invention, a process and catalyst has been developed for the hydrocracking of a wide variety of hydrocarbons, including whole crude oil as well as distillates and residual fractions, in the presence of. hydrogen and a crystalline zeolitic molecular sieve, large diameter spore free of cations, which supports a metal or a compound of the platinum or palladium series,

   or which is impregnated with this metal or this compound or which is mixed with these.



   Other characteristics and advantages of the present invention will emerge more clearly in the course of the detailed description which follows.



   The hydrocracking conditions used in connection with the catalyst, which will be described more fully below, preferably comprise passing the preheated feed through a fixed bed of a catalyst, at a temperature between about 288 and 538 ° C. , at (relative) pressures between 0 and 140 Kg / cm, preferably between about 14 and 84 Kg / cm, and at volumetric speeds of between 0.6 and 10.0 load weight units per catalyst weight unit per hour (P / P / hour) * Preferred hydrogen flow rates can be between 134 and 4470 m3 / 100 liters of hydrocarbon to be treated. It is of course possible to use the catalyst in the form of a fluid bed, a suspension or a fluidized bed.



   In accordance with the present invention, a remarkable hydrocracking catalyst is used formed by a composition comprising a metal or a compound of the platinum group deposited on an anionic network formed by a silica-crystalline alumina compound.

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 flax, or mixed with this network or incorporated into this network, the pores of which enter openings with a uniform diameter of between approximately 6 and 15 A.



   The uniform size of the pore openings of the catalyst support is a critical characteristic of the catalyst of the invention. For example, the pore openings of a crystalline molecular sieve of the Linde 4 A type have a size of about 4 A, while the pores of the calcium base exchange form have openings of about 5. are not large enough for branched chain paraffins * olefins, or cyclic compounds present in a hydride to be treated to enter or exit freely, The crystalline nature of the catalyst is important,

   because the particular crystalline structure controls the uniformity of the pore openings, which distinguishes this catalyst from other crystalline and non-crystalline zeolites as well as amorphous silica / alumina gel catalysts and catalysts based on 'aluminas.



   In a crystalline zeolite formed by an aluminosilicate, the actual structure comprises an anionic network with dispersed cations to ensure electrical neutrality.



   Normally, as prepared, these cations are sodium. In structure, the amount of sodium that is present has the same atomic content as aluminum, because, because the aluminum atom is trivalent, an additional charge must be present to compensate. its deficiency with respect to tetravalenta silicon atoms Thus, in the present invention, the catalyst support is obtained from a molecular sieve whose nominal composition is
Na2O.A12O3.xSiO2, in the anhydrous state, the size of the pore openings of the crystalline material being between 6 and 15 A.

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  Normally, to obtain a satisfactory catalyst support in a hydrocracking process, the sodium hydroxide content is too high, but it can be reduced to an acceptable level by base exchange with a more satisfactory cation, such as ammonium or hydrogen ions. This does not preclude the use of other metal cations during this base exchange operation, which cations could serve as catalytic agents by themselves and which could also improve the properties of the alumina-silicate crystals. serving as supports.



     Crystalline alumina silicates, of the molecular sieve-forming type and characterized by pores of 6 to 15 A, in which the SiO2 / Al2O3 molecular ratio is between about 2.2 / 1 and about 6.0 / 1, can be prepared. and more. SiO2 / Al2O3 Molecular ratios greater than 3/1 and preferably between 4.5 / 1 and 6.0 / 1 are particularly desirable. These materials are similar in (1) their adsorption properties, (2) their contact surfaces and pore volume, (3) their X-ray diffraction spectra, and (4) open them. pore tures.

   For example, in molecular sieves designated "13X" by Linde Co., the SiO2 / Al2O3 molecular ratio is typically about 2.7. A zeolite has been prepared which has similar pore openings and diffraction spectra, but in which the SiO2 / Al2O3 ratio is as low as 2.2. On the other hand, naturally occurring mineral faujasite has the same structure and other physical properties as 13X sieve, but the SiO2 / Al2O3 molecular ratio is about 5/1.

   Thus, sieves can be obtained whose pores have dimensions between 6 and 15 A, in which the molecular ratio SiO2 / Al2O3 exceeds a packed of 2.2 to 5/1 or more, molecular ratios greater than 3.0. / 1 being particularly preferred in the present invention.



   Large diameter molecular sieves between 6 and 15 A, with varying silica / alumina ratios

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      can be prepared in a manner well known in the art. The general way is the presence of the right amount and proper ratios of silica, alumina and caustic soda. These methods have been fully described in the literature.

   Treatment of an acid permutite with sodium silicate gives a large pore sieve, in which the silica-alumina ratio is 3.5 to 1. In faujasite, which is a natural zeolite molecular sieve having pore openings of the nature described and a similar x-ray diffraction spectrum, the SiO2 / Al2O3 ratio is about 5 to 1.



  So. in general, sieves with large pores can be prepared by using, in the reaction mixture, sodium aluminate, alumina sol, etc. for Al2O3, sodium silicate and / or a silica gel and / or a silica sol for SiO2, and an alkali hydroxide, free and / or in combination with the aforementioned constituents. The pH, the concentration of sodium ions in the mixture and the period of crystallization must be carefully controlled, all in a manner known in the art. even.



   These large pore screens are the supports used in accordance with the present invention, after the sodium content has been reduced by base exchange.



   To obtain a suitable catalyst for hydrocracking. most of the sodium, and in some cases all of it, is removed from the screen by a base exchange operation. To achieve this result, the sieve containing sodium can be reacted with ammonium ions; after calcination, the decationized or "hydrogen" form of the sieve remains. The presence of a certain quantity of sodium, which can range up to 105, calculated as Na2O, can be advantageous; a larger quantity causes the production of very dry synthesis gas and the deposition of coke. The soda content in the support of the screen of the present invention is between 0.5 and 10 and is preferably

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 this less than 8.5%.



   The operation in which the "hydrogen" form or NH4 form of the sieve is mixed with the noble metal may be of the type of a wet impregnation or a base screening reaction. Thus, a platinum or palladium salt or an ammonium complex thereof can be used, for example ammonium chloroplatinate Pt (NH3) 4Cl2, and many other products can be used. Palladium salts such as PdC12 can also be used, either for impregnation or for base exchange. The amount of catalytic metal in the finished catalyst is usually between 0.01 and about 5.0% by weight, preferably between 0.1 and 2.



   Many modifications can be made to the catalyst of the present invention without departing from its spirit,
Although it has maximum utility when a hydrogen atom replaces most of the sodium atoms in the initial sodium alumino-silicate, it may be desirable, in certain circumstances, to replace sodium. by other elements, such as cobalt, nickel, zinc, magnesium, calcium, cadmium, copper and barium, and to use the resulting crystalline compositions as a carrier for the metals of the group of platinum. Not only do these products serve as a support for the catalyst consisting of a metal of the platinum group, but also they possess catalytic activity by themselves.



   Thus, these catalysts can play a dual role in specific hydrocarbon conversion reactions. Other changes to the metal constituents of the adsorbent can give higher thermostability to the metal-containing composite catalyst. noble..



   Similarly, hydrogenated aluminosilicates can be prepared, although with greater difficulty, by thorough washing with water of the alkali sodium aluminosilicate, until the product obtained has a pH of essentially identical

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 to that of the wash water. Another method, which is less desirable, is to wash the sodium alumino-silicate thoroughly with large amounts of a dilute acid, such as hydrochloric acid, acetic acid, sulfuric acid, and acids. analogous acids. The wash acid should be diluted to such an extent that its pH is greater than about 3.8 and is preferably greater than about 4.5.

   In this way, the original structure of the alumino-silicate is retained. Lower pH could destroy the structure.



     The process of the invention will be better understood on reading the following examples, which are however given only as an indication and not as a limitation on the scope of the invention.



    EXAMPLE 1.



   This example describes the preparation of a typical catalyst which is used in the process of the present invention. In this example, the silica / alumina ratio in the catalyst carrier is 2.5 to 1.



   This example describes the preparation of a crystalline aluminosilicate adsorbent and having uniform pore openings large enough to adsorb branched chain hydrocarbons, aromatic hydrocarbons and naphthenes. 435 g of granular sodium metasilicate (Na2O.SiO2.5H2O), comprising approximately 29.1% Na20 and 28.7% SiO2, is dissolved in 1305 em3 of H2O at biante temperature.



  While vigorously stirring the solution, 265 g of a sodium aluminate solution, comprising 20% A1203 and the solids of which have the composition 3Na2O.2Al2O3, are added. After stirring the thick and dense precipitate for about 5 minutes, 1000 cm3 of H2O is added to dilute the suspension and facilitate its stirring.

   While the sodium silicate solution has an Na2O / SiO2 molecular ratio of about 0.98: 1, the approximate relative composition of the composite suspension is

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 about 5.4 Na20, Al20 ,. 4 8i02 '
The mixture is macerated at 82-99 C for 10 days. After cooling, the crystalline suspension is filtered, washed with water and dried in an oven heated to 135 C,
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 The crystals were then calcined for 4 hours at 454 .ü and subjected to examination to determine their adsorption capacity. A sample of the crystals was placed in an ampoule in
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 which we create a vacuum and which is maintained, 9 C,

   which is the boiling point of n-heptanoe. Naked portions of n-heptane are added until the internal pressure in the system has reached 500 mm Hg. It has been found that the capacity of adsorbent in this case is 0.20 cm of n-heptane (in liquid form) per gram of adsorbent.

   When the adsorbent is toluene, the measured capacity is 0.23 cm of toluene (in liquid form) per gram of adsorbent *
Chemical analysis of crystalline adsorbent shows
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 that it contains 47.8% of 6102 'bzz of Na20 and' 2.or, .6 of A1C These figures correspond to the approximate molecular composition Na20, Al20, * 2.5Si02 # EXAMPLE 2.-
As noted above, the silica / alumina ratio in the final crystalline product is, at least in part, a function of the ratio of their contents in solution. Preferably, the amounts of the silicate and aluminate solutions used
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 are such that the SiO 2 / Al 2 O ratio in the final mixture is between 2/1 and 10/1.

   In the present example, the preparation of a sieve with large diameter pores in which
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 the silica-alumina ratio is 3p3 to 1.



  564 g of granular sodium metasilicate (NaaO, sio205HZO) comprising approximately 29.1% Na2O and 28.7% SiO2 are dissolved in 1128 ml of H2O placed in a 4 liter container. While stirring the solution rapidly, at room temperature, 138 g of a solution are added.

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 sodium aluminate, comprising 20% Al2O3 and a composition, in the solid state, corresponding to 3Na2O.2Al2O3. When the aluminate solution is completely added, stirring is continued for 5 minutes and then an additional 1000 ml of water is added to dilute the suspension and facilitate its stirring. The relative composition of the suspension is approximately as follows: 11.3 Na2O.Al2O3. 10 SiO2.



   The suspension is hot macerated at temperatures between 85 and 88 ° C, using a reflux condenser to retain the liquid contents, for 190 hours. The product is cooled, filtered by suction, washed with about 1 liter of water and dried in a hot oven at 135 C. The X-ray diffraction spectrum of this product is similar to that of the material. Conventional 13X described in Example 1 and that of the mineral faujasite. Chemical analysis of the product shows that it contains 55.5% SiO2, 28.9%
Al2O3 and 15.6 na2O, which corresponds to a molecular composition of approximately 0.9 Na2O, Al2O3,3,3 SiO2.



   The crystalline material is weighed, after calcination at 454 C for 4 hours, and examined for adsorption capacity by the method described in Example 1,
When the adsorbate is n-heptane, the capacity of the material is 0.24 cc of n-heptane (in liquid form) per gram of adsorbent. When the adsorbate is toluene, the measured capacity is 0.27 cm of toluene (in liquid form) per gram of adsorbent product. When the adsorbate is 2-methyl pentane, the measured capacity / is 0.27 cm 3 of 2-methyl pentane (in liquid form) per gram of adsorbent.



     EXAMPLE 3 - Into a receptacle containing one liter of water are introduced, while stirring, 500 g of the retort prepared sodium alumino-silicate described in Example 1 and in the form of 1.58mm diameter extruded granules. In a container

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 separate 0.453 g of NH4Cl is dissolved in 1500 ml of H2O and 250 ml of concentrated NH4OH (NH3) are added. This mixed solution is added to the aqueous sieve suspension and the composite product is stirred by intermittent for 3 hours. The liquid is removed by decantation and the remaining solid material is washed twice with 500 ml of H2O. This ion exchange phase is repeated twice using each time
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 fresh solutions of NH40H-IHC1.

   The washed material was dried in an oven heated to 10400. The granules were then placed in a muffle oven and heated to 204 ° C. for 2 hours. The temperature was then raised to 2 ° C. for 4 hours. During this heating period, a considerable amount of ammonia is given off. The temperature is finally raised to 343 C and is
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 maintained at this level for 2 hours. A chemical analysis shows that the product contains 6.5% Na.0, 53.3 of 8.0 and 3915% of A12o "which corresponds to a molecular composition of approximately 0.25Nag0.Al2O5i2.3 SiO2 'La Calcined material comprises the anhydrous of the hydrogenated or dea-tionized form of bzz aluminowsilicate.



   2B6 g of the hydrogenated form of the alumina silicate are mixed with 1% platinum by contact with 180 ml of a solution comprising 2.86 g of Pt in the form of a soluble platinum salt. This catalyst, comprising 1% of Pt deposited on the form
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 molecular sieve hydrogenated, dried at J.04 ° C and is referred to as catalyst 1 in the following examples.



  EXAMPLE 4.wf - * <* <1 liter of H 20 and 400 g of sodium a7.uwino.-sl, sodium aate prepared as described in Example 1 and all in the form of extruded granules of 1 are mixed. , 58 mins. In another container, 0.453 kg of cobalt chloride (CoCl2, 6HgO) is dissolved in 390U ml of a solution of .5; ammonia. Air is bubbled through this solution while the complex product formed by the cobalt-amino chloride is formed,
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 1300 cm 3 of the cobalt solution is added to a salt

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 board tam1s-H2Q and stir intermittently for 90 minutes. The liquid is decanted and the remaining granules * are washed twice with 500 ml of H2O.

   This ion exchange operation is repeated gently times, using 1300 ml of the fresh cobalt-amine solution and 1 liter of H2O for each treatment *
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 The washed material is finally dried in an oven at .04 C.
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 then heat the granules for 2 hours at 20400, then for 4 hours z. 2bb C to decompose the amine couiplex. 01- Finally, the granules are heated at 454 C for 16 hours.



  The resulting granules then mainly comprise the cobalt furnace of the crystalline alumina silicate,:
445 g of the cobalt form of the aluminosilicate are contacted with 450 cm 3 of a solution comprising 4.5 g of Pt in the form of a soluble platinum salt.



  After maceration for 30 minutes, the composite product is placed
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 site in an oven heated to 104 C and dried slowly i to ensure better impregnation of the sieves with ions containing platinum *
This catalyst comprises 1% of Pt deposited on the cobalt form of the alumino-silicate constituting the mole sieve.
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 cular and. is referred to as tt Bit catalyst in the other examples.



  EXAMPLE 5 - mm m # * mi Kt m The hydrocoating activity of the catalyst is studied at 343 C "A" / and at atmospheric pressure using a charge of n-heptane. The flow rate of introduction in the liquid state is 1.3 V / V / hour and the hydrogen is introduced with a flow rate of 27 moles / of n-heptane. A fixed catalyst bed is used. Under these conditions, 17.3% of the feed is cracked in the form of hydrocarbons having a lower molecular weight * The cracked products mainly comprise about 26% of hydrocarbons.
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 total in 04 and 6,; b of total hydrocarbons in 5 'as connt3, tu ante principal.



   EXAMPLE 6

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The hydrocracking activity of catalyst "A" was further evaluated at 454 ° C. and under atmospheric pressure, using methylcyclohexane as the feed to be treated. The admission flow rate in the liquid state is 0.8 V / V / hour and the hydrogen is introduced with a flow rate of 27 moles / mole of methyl cyclohexane.



   A fixed catalyst bed is used. Under these conditions, 39.6% of the feed is cracked into C6 hydrocarbons and lighter hydrocarbons. Among these cracked products, the main ones are formed by 26% of total C hydrocarbons and 48% of total C6 acyclic hydrocarbons.



     EXAMPLE 7.-
The hydrocracking activity of catalyst "A" was re-evaluated at 490 C, using a feed consisting of a heavy naphtha from the first distillation. The boiling range of this naphtha is between 93 and 166 C, its density is 0.759 and its aniline point is 48 C. The naphtha contains, by: volume, 15% aromatics, 44% paraffins and 41% naphthens, as well as 40 ppm sulfur. The naphtha is sent to a fixed bed of catalyst "A" under a (relative) pressure of
14 Kg / cm, using 46.488 m of hydrogen added per 100 liters of naphtha, with a flow rate of 4.0 P / P / hour. The duration of treatment is 4 hours.

   In this operation, 10.1% of the naphtha is converted into products having 5 carbon atoms or less. These cracked products contain 64% of hydrocarbons in
C3 and 16% C4 hydrocarbons. The octane number of naphtha in
C6 + is improved.



   EXAMPLE 8.-
The hydrocracking activity of catalyst "B" was evaluated at 49,000 used, in a fixed bed operation, for a heavy first-distillation naphtha. This naphtha was described in Example 7. The naphtha is introduced at a flow rate of 4P / P / hour, with 46.488 m of hydrogen added per 100 liters of naphtha *

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 The pressure (relative) is 14 Kg / cm, and the treatment time is 4 hours. In this operation, 18.1% of the naphtha is converted into products having 5 carbon atoms or less.

   The main ones of these cracked products are: methane, 28, C3 hydrocarbons, 33% and C4 hydrocarbons, 28%.



    The clear octane number (from Research) of the remaining C6 + naphtha was increased from 58 to 80 by the catalytic treatment.



    EXAMPLE! 9.-
It is heated to reflux; at about 99 ° C., a mixture of sodium aluminate, caustic soda and silica sol, in proportions and for a time such that crystalline sieves are obtained in which the SiO2 / Al2O3 ratio is en, about 4 to 5.5. The sieve in the sodium form is then subjected to ion exchange with solutions of NH4OH-NH4CL to obtain a product containing less than 10% sodium hydroxide and preferably less than about 4%. The degree of base exchange is easily controlled by adjusting the duration of the contact and the number of exchanges.

   The resulting sieve can then be calcined to detect the ammonium compound, after which it is reacted with platinum or a platinum salt, such as ammoniacal PdC12, granulated and re-calcined, or the sieve can be treated in the ammonium form (or made to react) directly with an ammoniacal solution of a platinum or palladium salt to obtain the exchange of bases, filter it, dry it, transform it into granules and heat it slowly, then; Finally calcine it at 343-482 C to obtain what is called the decationized form of the sieve containing the catalytic agent.



   A sieve in which the SiO2 / Al2O3 ratio is about 5 and which contains 0.5% by weight of palladium is tested to determine its hydrocracking activity with various hydrocarbons to be treated.



    EXAMPLE 10.-
In this example, we compare the hydrocracking activity

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 a large diameter molecular sieve containing
 EMI16.1
 palladium and decationi8 <h, with the activity of hydrocracking conventional nickel sulfide in an amorphous silica-alumina gel catalyst.

   These operations are carried out in a pilot plant and the results given below summarize the results after an operation lasting 12 weeks.
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 Charge Ìu.le d rc 1a oa a t ue ld r Charge Pd / molecular sieve Ni3? / Al90, - large pore catalyst sio ata.yeur, brande tarez SiOg
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<tb> Pressure, <SEP> kg / cm2 <SEP> 105 <SEP> 56 <SEP> 105
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> V / V / hour <SEP> 1.0 <SEP> 1.3 <SEP> 0.5
<tb>
 
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 Temperature, pC 338 5'T1 360
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<tb> Conversion, <SEP>% <SEP> 60 <SEP> 60 <SEP> 40
<tb>
<tb>
<tb> Rate <SEP> of <SEP> deactivation <SEP> of
<tb>
<tb> catalyst, <SEP> 00 / day <SEP> 0.16 <SEP> 0.22 <SEP> 0.56
<tb>
 
The crude recycle charge contains approximately 50 ppm organic nitrogen compounds,

   and the nickel catalyst rapidly loses its activity at temperatures above 371 ° C. Thus, the nickel catalyst would have a life of about one month under the above conditions. On the other hand, under a pressure
 EMI16.6
 pressure (relative) of 105 Kg / cm, the Pd catalyst is not affected by a temperature of up to 399 C, which indicates a useful life of the catalyst of more than one year, under these conditions. , before regeneration is necessary. In addition, these results show that the catalyst formed by a molecular palladium tat can be used under conditions of temperature and pressure substantially less severe than the nickel catalyst without losing its activity.



  EXAMPLE 11.-
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 -¯IIiIt ..-----
As already mentioned, one of the great advantages of the palladium catalyst over catalysts comprising nickel sulfide deposited on a sili- gel composite product.

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   This alumina resides in the fact that the required pressure is lower This advantage is clearly demonstrated in the following comparison of two catalysts used with an oil of
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 Light catalytic recycle, which is hydrorefined and contains about 2 ppm nitrogen.
 EMI17.2
 



   reiiagium analyzer on Vaa..ror with a moldcu1a1 sieve- re-decationized cracking Sulfide of (large pores) N, / Si02 - Alg0 <
 EMI17.3
 
<tb> Pressure, <SEP> Kg / cm2 <SEP> 105 <SEP> 56 <SEP> 35 <SEP> 105 <SEP> 56
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> V / V / hour <SEP> 2.5 <SEP> 1.3 <SEP> 1.0 <SEP> 1.3 <SEP> 0.4
<tb>
 
 EMI17.4
 Temperature, 00 524 340 390 304 399
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<tb> Conversion, <SEP>% <SEP> 60 <SEP> 60 <SEP> 60 <SEP> 60 <SEP> 50
<tb>
<tb> <SEP> rate of <SEP> deactivation
<tb> 00 / day <SEP> 0 <SEP> 0.05 <SEP> - <SEP> 0 <SEP> 0
<tb>
 The operation under a (relative) pressure of 56 Kg / cm with a palladium catalyst extends over a period of 39 days or 87 days equivalent to 0.1 V / V / hour. During this period,

   the temperature required for a 60% conversion at 1 V / V / hour does not increase by more than 5.6 C.



    EXAMPLE 12.-
The palium catalyst is interesting for the production of premium motor gasoline (premium gasoline), compared to the hydrocra catalyst. quage with nickel sulphide, the palladium catalyst being more selective towards the light products and giving a better quality naphtha. Based on the yields of naphtha and the octane numbers, the palladium catalyst is shown to be particularly - particularly interesting for the production of premium motor gasoline

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<tb> Load <SEP> --- <SEP> Oil <SEP> of <SEP> recycling <SEP> crude-Catalyst <SEP> Sulfide <SEP> of <SEP> nickel <SEP> Palladium
<tb>
 
 EMI18.2
 Temperature,

   00 354-399 377 Pressure (relative) Kg / ema 105 wrrrwlwal Conversion, r.w.rurrwrrrrrrrrw, rr 60 rrrrwmrr
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<tb> Distributian <SEP> of <SEP> products
<tb>
<tb> Hydrocarbons <SEP> on <SEP> C3-. <SEP> weight <SEP>% <SEP> 3 <SEP> 4
<tb>
<tb> Hydrocarbons <SEP> in <SEP> C4, <SEP> vol. <SEP>% <SEP> 6 <SEP> 13
<tb>
 
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 Hydrocarbons in 05 / 190050ce vol, 53 g3 Hydrocarbuz ba in Ce / 22l "C, vol% 69 61
 EMI18.5
 
<tb> Quality <SEP> of the <SEP> products
<tb>
<tb>
<tb> Octane index <SEP> <SEP> Research <SEP> +3 <SEP> cm3 <SEP> TEL
<tb>
<tb>
<tb>
<tb> Hydr. <SEP> in <SEP> C5 / <SEP> 190,500 <SEP> 93 <SEP> 97
<tb>
<tb>
<tb>
<tb> Hydr. <SEP> en <SEP> C5 / <SEP> 221 C <SEP> 94 <SEP> 97
<tb>
 
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 Ootane index 'motor + 3cm' TEL Hydra in C, / 190.5 0 88 90 Hydr. in Cg / 221 <'C 87 90 TEL lead tetrathr, e
 EMI18.7
 r't lPrw ..



   Due to the high nitrogen content of some feeds to be treated, it is extremely difficult to subject them to hydrocracking. Nitrogen compounds have been found to decrease the activity of most hydrocracking catalysts very extensively; compensating for this decrease in activity by increasing the temperature generally increases the rate of catalyst deactivation to such an extent that it cannot be used satisfactorily in a continuous process.
 EMI18.8
 naked without regenerating it at excessively close intervals.



  However, the catalyst of the present invention has been found to be more resistant to the deleterious effects of nitrogen compounds. With a gas oil obtained by coking a residue from the distillation of petroleum, and which contains much more nitrogen than the product of re-

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 Catalytic cycling used in the previous examples, the palladium catalyst gives a 25% conversion rate of 0.5 V / V / hour, a (relative) pressure of 105 Kg / cm2 and a temperature of 427 C.

   Under these conditions, the conventional hydrocracking catalyst (such as a nickel sulphide cracking catalyst deposited on a silica-alumina composite product) would be almost immediately completely deactivated. however, the catalyst of the present invention retains its activity for at least 6 days, which is the duration of the test.

   
 EMI19.1
 
<tb> Diesel <SEP> from- <SEP> Oil <SEP> from <SEP> recy-
<tb>
 
 EMI19.2
 coking light tick cataly-4 ltap- clage mmMmmmimmmmmmmmmmm
 EMI19.3
 
<tb> Boiling range <SEP>, <SEP> C <SEP> 232-454 <SEP> 204-321
<tb>
<tb> Density <SEP> 0.9329 <SEP> 0.880
<tb>
<tb> Nitrogen, <SEP> ppm <SEP> 1340 <SEP> 50 <SEP>
<tb>
<tb> Sulfur, <SEP> weight <SEP>% <SEP> 1.07 <SEP> 0.38
<tb>
<tb> EXAMPLE <SEP> 14.-
<tb>
 
To determine whether the exceptional hydrocracking properties of the catalyst of the present invention are due to the combination of a noble metal or an active cracking catalyst containing mixed oxides, or whether they are due to the nature of the support,

   the activity of the catalyst of the present invention was compared with that of a palladium catalyst on a conventional silica gel-alumina cracking catalyst. The results below show the notable superiority of the catalyst formed by a crystalline molecular sieve with large pores mixed with palladium,

 <Desc / Clms Page number 20>

 
 EMI20.1
 Tablez ai - - - - -
 EMI20.2
 Pd catalyst / Molecular sieve (large pores, deca1;

  d.onized) Pd on amorphous cracking catalyst Composition 095% Pd ik 0,% Pd on 13% of Alê3es?% 5i02 Working conditions a ¯ā JËL-J Load (1) aa ---- ..! L ab gemp.s .0 - 322.2 307.7 3122 311.6 312.2 ######## - "-} 1.5, .5 Tempe * 32292 30717 31292 31116 $ 312 2 Breton (relative), 68960 69980 66935 66.50 6592 65.1 70, 70 $ 21 C-9386 70.21 68.6? Duration hours of the experiment, 1-38 42-62 66-85 92-110 116-182: B2- f- 42 -62 66-85 92-110 116-182 1822DE Flow rate V / V / hour}, 14 ".54 3.41 3,? 5 2137 2.57'2 2s41 3s19? J, 41.- 1.70 2, 2? \ Gas flow (without recycling) 920 81? yy 40 683 929.7 1022 ,? 770.6 722.3 876.1 65? S9 M31100 liters 817 847 772 740 683 92997 1022s? ? 7Os6 722, to3 87691 65719
 EMI20.3
 
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<tb>
 
 EMI20.4
 Density 0.7487 0.7927 Oa79O9 0 = 8011 01800 0i8612 0 * 8193 O, 8.5} 9 8280 8284 0.8571 0 5;

   D t l 'to eng. 204 C 86 58 62 52 31 10 28 24 25 24 7 0 Conversion rate rlt1 90 66? 3 65 33 15 32 25 41 43 8 0 Rate corrected for 3 / V / V / hour 91 72 77 73 27 z.3 28 2I 4 '47 (1) a. Light catalytic recycle oil bydroraffined. b. Recycle oil: Crude light analytical. dom "%

 <Desc / Clms Page number 21>

 EXAMPLE 15.-
The hydrocracking activity of the large pore sieve mixed with palladium and decationized was evaluated in a further series of experiments, by comparing its activity in terms of its dealkylation activity by hydrogenation with that of the plus catalyst. conventional comprising platinum treated with chlorine and deposited on alumina.



  In the present example, the feed to be treated is a mixture of ethylbenzene and xylene. The results show the high activity of hydrogenation and dealkylation by hydrogenation of the catalyst, and they prove that it can be used to prepare benzene and naphthalene from starting materials such as catalytic naphtha. recycle oils and other aromatic feeds rich in aromatic alkyl products.

   Typical conditions for dealkylation by hydrogenation include temperatures of 488 to 499 C, (relative) pressures of 14 to 19.95 Kg / cm2, H 2 / hydrocarbon ratios of about 5, and feed rates of. about 0.5 to 1.0 P / P / hour. The catalyst was activated by a hydrogen treatment of a
2 rea of 3 hours, at a (relative) pressure of 21 Kg / cm and a temperature of 527 C.



   In the specific example, the temperature is 488 C, the feed rate is 0.5 P / P / hour, the partial pressure of hydrogen is 12.6 Kg / cm2 and the partial pressure of the hydrocarbon is 2.50 Kg / cm2.
 EMI21.1
 
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  Load <SEP> Yields, <SEP> weight / of <SEP> the <SEP> load
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<tb> Weight <SEP>% <SEP> Sieve, Pd / H <SEP> 0.6% <SEP> Pt / Al2O3
<tb>
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<tb> Benzene <SEP>) <SEP> 0.6 <SEP> 24.3
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<tb> products <SEP> aroma- <SEP> 0,0 <SEP> 0,0 <SEP> 0,0
<tb>
 

 <Desc / Clms Page number 22>

 
The catalyst (Pd / decationized large pore molecular sieve) gives about 10 times more benzene than the conventional platinum / alumina catalyst.



   Although the invention is of particularly interesting application when the sieve is decationized, it is of course, as has been pointed out, that one also obtains interesting results when the sodium cation which is regularly present. is replaced by other cations, including noble metal cations. Thus, a sieve in the calcium form prepared by base exchange of a sieve in the large pore sodium form with calcium chloride, followed by mixing with a palladium salt and reduction, possesses - a marked hydrocracking activity. The results obtained during hydrocracking with a cobalt sieve supported on platinum were given in Example 8.

   In addition, although the efficiency of large pore sieves varies widely, in general, the higher the Sio2 / Al2O3 ratio, the greater the efficiency. Further, according to the present invention, it is possible to add dos activating agents to the sieves supported by noble metals * These agents can be transition metals, their oxides or their sulphides and in particular the metals and compounds of groups VB, VIB, VIIB and VIIIB, as well as their mixtures *
The expressions "pore openings" or "pore diameter" used in the present disclosure are fully described in "The Structure of Synthetic Molecular Sieves" by L. Broussard and D.P.

   Shoemaker in "J.A. 0, S." 82, 1960, pages 1041-1051. X-ray diffraction measurements have made it possible to observe the synthetic and natural baths with large pores, whatever the SiO2 / Al2O3 ratio. pores whose diameter is essentially of the order of magnitude and whose size is large enough to allow the admission of hydro-

 <Desc / Clms Page number 23>

 branched chain carbides and most of the ordinary cyclic hydrocarbons.



   Numerous modifications can be made to the embodiments described above. Attention has already been drawn to the modified technique of preparing catalysts in which one can form a composite with the platinum group metal and the ammonium form of the sieve, and then calcine this composite. In addition, it is important that the screen support be crystalline in nature when mixed with the metal or platinum group compound, in order to obtain the advantageous results of the present invention; retention of this crystal structure is not necessary in all cases.



   CLAIMS. -
1) A process for hydrocracking hydrocarbons to obtain products whose boiling range is lower than that of these hydrocarbons, in which these hydrocarbons are subjected to hydrocracking conditions in the presence of added hydrogen and 'a catalyst consisting of a metal from the platinum group mixed with a crystalline zeolitic molecular sieve of the metallic alumino-silicate type having pores of a uniform diameter of between 6 and 15 A and in which the molecular ratio silica / alumina is at least 2.2 to 1, this sieve being further characterized in that it does not contain more than 10% sodium, calculated as Na2O.


    

Claims (1)

2) The method of claim 1, wherein the platinum group metal is platinum 3) The process of claim 1, wherein the platinum group metal is palladium, 4) The process according to any one of claims 1 to 3, wherein the treated hydrocarbon is a gas oil fraction. 5) The method according to any one of the claims <Desc / Clms Page number 24> 1 to 3, wherein the hydrocarbon is a naphtha moiety. 6. The process according to any one of claims 1 to 3, wherein the hydrocarbon in question is a residual oil. 7) The process according to any of claims 1 to 3, wherein the hydrocarbon is whole crude oil. 8) The process according to any one of claims 1 to 3 in which the aforementioned fractions are rich in aromatic alkyl products. 9) The process of any one of claims 1 to 3, in which the hydrocracking conditions are the following temperature between 260 and 538 C, (relative) pressures between 0 and 140 Kg / cm, volumetric speeds included between 0.6 and 10.0 weight units of the feed per unit weight of the catalyst and per hour. 10) The process of any one of claims 1 to 3, wherein the flow rate of hydrogen is between about 134 and 4470 m3 / 100 liters of loaded hydrocarbon. 11) the process of any one of claims 1 to 3, wherein the sieve is subjected to a base exchange process with a cation such as hydrogen, cobalt, nickel, zinc, magnesium, calcium, cadmium, copper and barium. 12) The process of any one of claims 1 to 3, wherein the amount of platinum group metal is between 0.01 and 5% of the weight of the composite catalyst. 13) The process of claim 1, wherein the molecular sieve is decationized by converting the sieve in sodium form to sieve in ammonium form, this sieve is then calcined and then mixed with a compound of a group metal platinum which can be decomposed by heat. <Desc / Clms Page number 25> 14) The process of any one of claims 1 to 3, wherein the silica / alumina ratio in this sieve is greater than 3.0 / 1. 15. A process according to claim 1, in which a petroleum distillation fraction is sent to a hydrocraquate zone; a temperature between 288 and 482 C, a (relative) pressure between 35 and 105 Kg / cm, a hydrogen feed rate of 13.4 to 4470 m3 / 100 liters d 'charged hydrocarbon, a hydrocracking catalyst comprising a decationized molecular sieve containing not more than 8.5% sodium, calculated as Na2O and whose pores have a diameter of 6 to 15 A and are large enough to pass molecules of benzene, this sieve having a silica / alumina molecular ratio greater than 3, 0/1 and being mixed with 0.05 to 5.0% by weight of a Group VIII metal, after which a hydrocracked product is recovered. 16) The process of claim 15, wherein the charged hydrocarbon is a gas oil fraction. 17) The process of claims 15 or 16., wherein ',' the metal of group VIII is platinum. 18) The process of claims 15 or 16, in which the metal of group VIII is palladium. 19) A process for hydrocracking hydrocarbon streams, as described above.