FR2483253A1 - Hydrocarbon conversion catalysts, esp. for reforming - contg. platinum-group metal, hafnium and group=iib metal - Google Patents

Abstract

New catalysts comprise 100 pts. wt. of a support, 0.05-0.6 (pref. 0.1-0.5) pts. wt. of a Pt-gp. metal (M), 0.005-5 (pref. 0.01-3, esp. 0.05-0.4) pts. wt. of Hf, 0.005-5 (pref. 0.05-3, esp. 0.08-1) pts. wt. of at least one metal (M') selected from Zn, Cd and Hg, and 0.1-15 pts. wt. of a halogen. The support is pref. alumina. M is pref. Pt or Ir and M' is pref. Cd or Zn. The catalysts can be prepd. by impregnation in one or more stages, e.g. by impregnation with an aq. soln. contg. HCl, H2PtCl6, HfOCl2 and M'Cl2. The catalysts are esp. useful for reforming or aromising, but can also be used for hydrocracking, isomerisation of alkyl- aromatics, hydroisomerisation of 4-7C paraffins, or hydro- or steam-dealkylation of alkylaromatics. Incorporation of both Hf and M' increases the selectivity of the catalysts, esp. when used for continuous high-severity reforming (to RON = 102+) in a series of at least 2 mobile-bed reactors.

Description

 The invention relates to novel hydrocarbon conversion catalysts.

 These catalysts contain a support, a noble metal of the platinum family, hafnium, at least one metal selected from zinc, cadmium and mercury and a halogen or a halogenated compound.

They are used in particular for a catalytic reforming (or reforming) process as well as for a catalytic process for the production of aromatic hydrocarbons, processes carried out for example at a temperature of between 430 and 600 ° C., under an absolute pressure of between 0.1 and 3s5 MPa (0.1 MPa = 1 kg / cm) with a hourly rate of between 0.1 and 10 volumes of liquid filler per volume of catalyst, the hydrogen / hydrocarbon molar ratio being between 1 and 20 The catalysts according to the invention make it possible in particular to carry out these two processes under severe conditions, thus the use of the new catalysts applies.
- The reforming reactions to obtain a gasoline with a clear octane number greater than or equal to 102. The severe conditions of the hydroreforming reactions or catalytic hydroreforming are more particularly the following: the average temperature is between about 510 and 580 ° C, the pressure is between about 095 and 1.8 MPa, preferably 0.6 and 1.3 MPa, the hourly speed is between 1 and 10 volumes of liquid charge per volume of catalyst and the The recycle ratio is from 6 to 10 moles of hydrogen per mole of filler The filler is generally a naphtha distilling at about 60 ° C to about 220 ° C, particularly a straight-run naphtha.
- reactions for the production of aromatic hydrocarbons from unsaturated or unsaturated gasolines (for the production of benzene, toluene, and xylenes). If the charge is unsaturated, ie if it contains diolefins and monoolefins, it will first have to be disposed of by selective or total hydrogenation. Subsequently, the charge possibly freed by hydrogenation of substantially all of its diolefins and monoolefins, when it is contained, is subjected to a treatment with hydrogen, in the presence of a catalyst, at a temperature of between approximately 530 and 600 ° C. at a pressure of between 0.1 and 1.3 MPa, the hourly volumetric flow rate of the liquid feed being of the order of 1 to 10 times the volume of the catalyst, the hydrogen / hydrocarbon molar ratio being of the order of 6 20.The charge may consist of pyrolysis gasolines, cracking gas, in particular steam-cracking, or catalytic reforming, or still consist of naphthenic hydrocarbons capable, by dehydrogenation, of being transformed into aromatic hydrocarbons.

 The catalysts according to the invention are also suitable for hydrocracking reactions which are generally carried out at a temperature of between about 260 and 530 ° C and a pressure of between about 0.8 and 25 MPa. hourly liquid space, or LHSV, or volume per hour of liquid charge at 15 ° C per volume of catalyst, from about 0.1 to 10.0, preferably having an upper limit of about 4.0 and a flow rate of hydrogen circulation of about 1 to 20 moles / mole of filler.

 The catalysts of the invention are also suitable for isomerization reactions of aromatic hydrocarbons (xylenes for example) reactions which are generally carried out at a temperature of between about 200 and 600 ° C, at a pressure of between about 0.005 and 7 MPa , the hourly volumetric flow being between 0.1 and 10 times the volume of catalyst.

 The catalysts of the invention are also suitable for isomerization in a hydrogen atmosphere of saturated hydrocarbons having 4 to 7 carbon atoms, a temperature of between 50 and 250 OC, for example 100-200 OC. It is preferably carried out under a pressure of 0.5 to 10 MPa with a space velocity of 0.2 to 10 liters of filler per liter of catalyst per hour. The molar ratio H 2 / hydrocarbons is, for example, between 0.01: 1 and 20: 1.

 The catalysts of the invention are also suitable for the hydrodealkylation reactions of aromatic hydrocarbons or the dealkylation with water vapor of aromatic hydrocarbons, these reactions being carried out under the known operating conditions, generally between 300 and 600 ° C., for example, to manufacture benzene from toluene or from other alkylbenzenes.

 The catalysts can be used in a moving bed, particularly for reforming reactions and for producing aromatic hydrocarbons, reactions for which a preferred method consists in using several moving-bed reactors.

 The charge flows successively in each reactor or reaction zone following an axial or radial flow (radial meaning a flow from the center to the periphery or from the periphery to the center). The reaction zones are arranged in series, for example side-by-side or superimposed. Preferably, reaction zones placed side by side are used. The charge flows successively through each of these reaction zones, with intermediate heating of the charge between the reaction zones; the fresh catalyst is introduced at the top of the first reaction zone where the fresh feed is introduced; it then flows gradually up and down this zone from which it is withdrawn progressively from below, and by any appropriate means (lift in particular in the case of reactors arranged side by side), it is transported to the top of the next reaction zone in which it flows gradually also from top to bottom, and so on until the last reaction zone at the bottom of which the catalyst is also withdrawn gradually and then sent to a regeneration zone. At the exit of the regeneration zone, the catalyst is gradually reintroduced into the top of the first reaction zone. The various catalyst withdrawals are carried out as indicated above "progressively", that is to say either periodically or continuously. Racking, continuously, is preferred to periodic racking.

 Catalysts containing a platinum-family metal deposited on a support have been known for a long time. But in spite of the many improvements that have since been made to these catalysts, for example by the incorporation of one, two or even three other metals chosen from the most diverse groups of the periodic table of elements, we are still striving today to seek new catalysts which on the one hand would give even better yields than those obtained so far and which on the other hand would also have a longer life than known catalysts.

In addition, efforts are being made to improve the mechanical properties of these catalysts, in particular to enable their use in a moving bed, in the form of agglomerates, for example beads or extrudates, of appreciable size, so as to leave a relatively easy passage to gaseous reactants. The wear of these catalysts results in the formation of much finer grains which gradually obstruct the free space and force to increase the inlet pressure of the reagents or even to interrupt the operation.

 It has now been discovered that by operating in the presence of very specific catalysts, these specific catalysts have an activist, but especially an increased lifetime, compared to the catalysts of the prior art.

 The specific catalyst used in the present invention contains a support, a noble metal of the platinum family, afnium and a third metal chosen from zinc, cadmium and mercury and a halogen, for example chlorine or chlorine. fluorine. Preferred noble metals of the platinum family are platinum, rhodium and iridium.

The third preferred metal is zinc or cadmium.

 The catalyst according to the invention contains, by weight relative to the support (a) from 0.05 to 0.6% and more particularly from 0.1 to 0.5% of noble metal of the platinum family, (b) 0.005 to 5%, preferably 0.01 to 3% and more particularly 0.05 to 0.4% of afnium, (c) 0.005 to 5%, preferably 0.05 to 3% and more particularly 0.08 to 1%. Zinc and / or cadmium and / or mercury and (d) 0.1 to 15% by weight, relative to the support, of a halogen, for example chlorine QU fluorine.

 The supports are generally chosen from the oxides of metals of groups II, III and / or IV of the periodic classification of elements, such as, for example, oxides of magnesium, aluminum, titanium, zirconium, thorium or silicon, taken alone or mixed with each other or with oxides of other elements of the periodic table, such as, for example, boron and / or antimony.

You can also use coal. It is also possible to use zeolites or molecular sieves of the X and Y type, or of the mordenite, faujasite or ZMS-5 type, ZMS-4 type, ZMS-8 type, and the like, as well as mixtures of metal oxides. groups II, III and / or IV with zeolite material.

 For reforming or aromatic hydrocarbon reactions and isomerization reactions of paraffinic or aromatic hydrocarbons, the preferred support is alumina; the specific surface area of the alumina may advantageously be between 50 and 400 m per gram, preferably between 80 and 300 m 2 / g.

 The catalyst can be prepared by conventional methods of impregnating the support with metal compound solutions that are desired to be introduced. We use either a common solution of these metals, or separate solutions for each metal.

When several solutions are used, it is possible to carry out drying and / or intermediate calcinations. It is usually terminated by calcination for example between about 500 and 10,000 cc, preferably in the presence of free oxygen, for example by conducting an air sweep.

 As examples of metal compounds used in the composition of the catalyst, mention may be made, for example, of the nitrates, chlorides, bromides, fluorides, sulphates, ammonium salts or acetates of these metals, or any other salt or oxide of these metals soluble in water, hydrochloric acid or any other suitable solvent.

 The halogen of the catalyst may come from one of the metal halides, if the metal is introduced by means of one of the halides, or may be introduced in the form of hydrochloric acid or hydrofluoric acid, ammonium chloride, ammonium fluoride, chlorine gas, or hydrocarbon halide, for example Col4, CH2Cl2 or CH3l etc.

 A preparation method consists, for example, in impregnating the support with an aqueous solution, for example oxychloride or other hafnium compound, drying at 120 ° C. and calcining under air for a few hours at a temperature of between 500 and 10,000 ° C .; then a second impregnation followed by a solution containing the platinum family metal and the metal selected from zinc, cadmium and mercury.

 Another method is, for example, to impregnate the support with a solution containing both the three constituents of the catalyst.

 Yet another method is to introduce the selected promoters by performing as many successive impregnations as there are constituents in the catalyst.

 An important application of the invention is the production of a gasoline of very high octane number which requires operating under very severe conditions that hardly support the catalysts used until today. The use of bimetallic catalysts, however, has made a marked improvement. Numerous attempts at metal combinations have been made and catalytic compositions containing up to 4 and even 5 metals have been seen. These compositions have certainly provided an improvement but generally, if the promoters used provide good stability characteristics. , they also bring, unfortunately, especially in the case of noble metals of the platinum family, a certain tendency towards hydrogenolysis, which ultimately leads to a decrease in yields and a shortening of the duration of the cycle and the possible number of cycles, ie a decrease in the life of the catalyst.

 However, the simultaneous use of afnium and zinc (or cadmium and / or mercury) together with a noble metal of the platinum family, very much attenuates this state of affairs by significantly reducing this hydrogenolysing tendency, and the it has been found that the benefits provided by each of the three metals are optimal in the case of severe operating conditions, particularly under low pressures, high temperatures and long operating times.

 The examples below illustrate the invention without limiting it.

Example 1

In order to obtain a gasoline having a clear (or clear) octane number of 103, it is proposed to treat a naphtha having the following characteristics:
- ASTM distillation ...................... 80 - 160 OC
- composition
. aromatic hydrocarbons ... ....... - 7% by weight
. naphthenic hydrocarbons ........... 27% by weight
paraffinic hydrocarbons ........... 66 66% -by weight - octane number "clear research about 37
- average molecular weight 0 110
density at 20 ° C .; 0.782
This naphtha passes with recycled hydrogen on two catalysts A and B containing 0.4% of platinum and 0.25% of afnium by weight relative to the support which is an alumina having a specific surface area of 240 m 2 / g and a pore volume of 0.57 cm3 / g; the chlorine content of catalysts A and B is 1.12%. Catalyst A additionally contains 0.5% cadmium and catalyst B additionally contains 0.5% zinc (by weight relative to the support).

Catalysts A and B were prepared by adding to 100 g of alumina, 100 cm3 of an aqueous solution containing
1.90 g of concentrated HCl (d = 1.19)
20 g of an aqueous solution of chloroplatinic acid containing 2% by weight of platinum
5 g of aqueous hafnium oxychloride solution containing 5% by weight of hafnium,
and 10 g of an aqueous solution of cadmium chloride containing 5% by weight of cadmium for catalyst A,
or 10 g of aqueous zinc chloride solution containing 5% by weight of zinc for catalyst B.

It is left in contact for 5 hours, filtered off and dried for 2 hours at 100 ° C. and then calcined at 530 ° C. in dry air (drying of the air with activated alumina). Then it is reduced under a current of dry hydrogen (activated alumina) for 2 hours at 460 C. The catalysts A and B obtained contain - 0.4 X of platinum - 0.25% of hafnium - 0.5% of cadmium (catalyst A) or 0.5% zinc (catalyst
B)
- 1.12% chlorine.

 The catalysts A and B obtained have a surface area of 230 m 2 / g and a pore volume of 0.54 cm 3 / g.

 A continuous operation is carried out in a moving bed in three reactors of substantially identical volumes.

The operating conditions are as follows
pressure: 1 MPa (lo kg / cm 2)
- temperature: 530 "C
- molar ratio H2 / hydrocarbons: 8
naphtha weight / catalyst weight / hour: 1.65
It is also carried out in the presence of various catalysts of the prior art not according to the invention comprising 1,2 or 3 metal elements. All catalysts contain 1.12% chlorine.

 Table I shows, after 200 hours, the yield obtained in C5 + and the percentage of hydrogen contained in the recycle gas.

 The results obtained in this example 1, with the catalysts according to the invention can be maintained over time, that is to say over very long periods of time. several months for example, operating as indicated, ie continuously, in the system with 3 moving bed reactors, the catalyst being withdrawn for example continuously, at a speed adjusted so that the entire catalytic bed the reactor is gradually renewed with fresh catalyst for example in about 500 hours.

Table I.

<Tb>

Cata- <SEP> Yield <SEP> Gas <SEP> recy
Metal <SEP>% <SEP><SEP> by <SEP> report <SEP> at <SEP> support <SEP> Yield <SEP> Gas <SEP> recy
<tb> ly- <SEP> Metal <SEP> of the <SEP> catalyst <SEP> c5 + <SEP> clage <SEP>% <SEP> H2
<sep>SEP><SEP> catalyst <SEP> (weight) <SEP> (molar)
<tb> seur
<tb><SEP> A <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> hafnium <SEP> 0.5 <SEQ> cadmium <SEP> 79.9 <SEP> 79.8
<tb><SEP> F <SEP> 0.4 <SEP> Platinum <SEP> - <SEP><SEP> - <SEP><SEP> 73.4 <SEP> 72.9
<tb><SEP> C <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Hafnium <SEP> - <SEP><SEP> 76.5 <SEP> 75.9
<tb><SEP> D <SEP> 0.4 <SEP> platinum <SEP> - <SEP> 0.5 <SEP> cadmium <SEP> 73.9 <SEP> 74.1
<tb><SEP> B <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> hafnium <SEP> 0.5 <SEP> zinc <SEP> 79.9 <SEP> 79., 8 <September>
<tb><SEP> E <SEP> 0.4 <SEP> Platinum <SEP> - <SEP> 0.5 <SEP> Zinc <SEP> 73.7 <SEP> 74.0
<tb><SEP> G <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> iridium <SEP>. <SEP> 0.5 <SEQ> cadmium <SEP> 79.3 <SEP> 78.4
<tb><SEP> H <SEP> 0.4 <SEP> Platinum <SEP> 0.08 <SEP> Iridium <SEP> 0.5 <SEP> Cadmium <SEP> 79.3 <SEP> 78.4
<tb><SEP> I <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> iridium <SEP> 0.5 <SEP> zinc <SEP> 79.1 <SEP> 78.5
<tb><SEP> J <SEP> 0.4 <SEP> Platinum <SEP> 0.08 <SEP> Iridium <SEP> 0.5 <SEP> Zinc <SEP> 79.1 <SE> 78.6
<tb><SEP> K <SEP> 0.4 <SEP> platinum <SEP> 0.08 <SEP> iridium <SEP> - <SEP> 75.2 <SEP> 74.9
<Tb>
Example 2

 Example 1 was repeated with catalysts containing platinum, hafnium, cadmium or zinc and the contents of hafnium, cadmium or zinc were varied. The metal contents and the results obtained are given in Table II. All catalysts contain 1.12% chlorine.

Table II.

<Tb>

: at; a- <SEP> Mets <SEP> I <SEP> by <SEP> reminder <SEP> a <SEP> support <SEP> IRendance <SEP> Gas <SEP> recy
<tb><SEP> of the <SEP> catalyst <SEP> r + <SEP> clage <SEP> Z <SEP> H2
<tb><SEP> (weight) <SEP> (molar)
<tb> seur <SEP> (weight) <SEP> (malairc)
<tb><SEP> A1 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 0.003 <SEP> cadmium <SEP> 76.5 <SEP> 75.9
<tb><SEP> A2 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 0.03 <SEQ> cadmium <SEP> 78.0 <SEP> 77.6
<tb><SEP> A3 <SEP> 0.4 <SEP> Platinum <SEP> 0.25 <SEP> Hafnium <SEP> 0.07 <SEP> Cadmium <SEP> 79.6 <SEP> 79.5
<tb><SEP> A <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 0.5 <SEQ> cadmium <SEP> 79.9 <SEP> 79.8
<tb><SEP> A4 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 2 <SEP> cadmium <SEP> 79.6 <SEP> 79.5
<tb><SEP> A5 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 4 <SEP> cadmium <SEP> 77.9 <SEP> 77.5
<tb><SEP> A6 <SEP>0> 4 <SEP> platinum <SEP> 1 <SEP> 0.25 <SEP> hafnium <SEP> 6 <SEP> cadmium <SEP> 76.1 <SEP> 75, 6
<tb><SEP> o
<tb><SEP> B1 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 0, -003 <SEP> zinc <SEP> 76.5 <SEP> 75.9 <September>
<tb><SEP> B2 <SEP> 0, .4 platinum <SEP> 0.25 <SEP> hafnium <SEP> 1 <SEP> 0.03 <SEP> zinc <SEP> 78.6 <SEP> 77.5
<tb><SEP> B3 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP>'<SEP> 0.07 <SEP> zinc <SEP> 79.4 <SEP> 79.5
<tb><SEP> B <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 0.5 <SEP> zinc <SEP> 79.9 <SEP> 79.8
<tb><SEP> B4 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 2 <SEP> zinc <SEP> 79.4 <SEP> 79.5
<tb><SEP> B5 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hafnium <SEP> 4 <SEP> zinc <SEP> 78.6 <SEP> 77.5
<tb><SEP> B6 <SEP> 0.4 <SEP> platinum <SEP> 0.25 <SEP> hanium <SEP> 6 <SEP> zinc <SEP> 76.3 <SEP> 75.2
<tb><SEP> L1 <SEP> 0.4 <SEP> platinum <SEP> 0.003 <SEP> hafnium <SEP> 0.5 <SEP> cadmium <SEP> 73.9 <SEP> 74.1
<tb><SEP> L2 <SEP> 0.4 <SEP> platinum <SEP> 0.003 * hafnium <SEP> 0.5 <SEP> zinc <SEP> 73.7 <SEP> 74.0
<tb><SEP> L3 <SEP> 0.4 <SEP> platinum <SEP> 0.008 <SEP> hafnium <SEP> 0.5 <SEP> cadmium <SEP> 78.2 <SEP> 77.8
<tb><SEP> L4 <SEP> 0.4 <SEP> platinum <SEP> 0.008 <SEP> hafnium <SEP> 0.5 <SEP> zinc <SEP> 78.1 <SEP> 77.7
<tb><SEP> L5 <SEP> 0.4 <SEP> Platinum <SEP> 0.03 <SEP> Hafnium <SEP> 0.5 <SEQ> Cadmium <SEP> 79.7 <SEP> 79.6
<tb><SEP> L6 <SEP> 0.4 <SEP> platinum <SEP> 0.03 <SEP> hafnium <SEP> 0.5 <SEP> zinc <SEP> 79.7 <SEP> 79.5
<tb><SEP> L7 <SEP> 0.4 <SEP> platinum <SEP> 2 <SEP> hafnium <SEP> 0.5 <SEQ> cadmium <SEP> 79.6 <SEP> 79.4
<tb><SEP> 8 <SEP> 0.4 <SEP> platinum <SEP> 2 <SEP> hafnium <SEP> 0.5 <SEP> zinc <SEP> 79.6 <SEP> 79.3
<Tb>
Example 3

 Catalysts A and B prepared in Example 1 are used in a process for producing aromatic hydrocarbons.

These two catalysts are passed over with hydrogen, a charge of the following composition by weight
- isopentane + n.pentane ..................... 1,59%
- isohexanes + n.hexane ...................... 24,22%
- isoheptanes + n.heptane .................... 42.55%
- cyclopentane 0. 0,13%
methylcyclopentane ........ 6.72%
- cyclohexane ................... .............. 5.50%
- # naphthenes in C7 .......................... 15,81%
- # naphthenes in C8 .......................... 0,14%
benzene 0 1.68%
toluene 0 1.66% 100.

The operating conditions were as follows
pressure: 1 MPa
- temperature: 550 C
- hourly flow of liquid charge: 3 times the volume of the catalyst
- molar ratio hydrogen / charge: 6
The results are shown in Table III where, according to the age of the catalyst, the weight contents of benzene, toluene, benzene + toluene, relative to the initial charge, as well as the C5 + weight yield are indicated.

Table III.

<tb><SEP> Composition <SEP> \ <SEP> Age <SEP> d-ü <SEP> catalyzed
<tb><SEP> cata- <SEP> composition <SEP> Age <SEP> of <SEP> 30- ~ hours <SEP> 200 <SEP> catalyzed
<tb><SEP> of the <SEP> weight <SEP> L <SEP><SEP> in <SEP> 30-hours <SEP> 200 <SEP> hours <SEP> 400 <SEP> hours
<tb><SEP> - <SEP> Benzene <SEP> 26.9 <SEP>% <SEP> 26.6 <SEP>% <SEP> 26.0 <SEP>%
<tb><SEP> - <SEP> Toluene <SEP> 35.3 <SEP> 35.3 <SEP> 35.0 <SEP>% <SEP> 34.5 <SEP> X
<tb><SEP> - <SEP> Benzene <SEP> + <SEP>t; olune <SEP> i <SEP> 62.2 <SEP>% <SEP> 61.5 <SEP>% <SEP> 60, 5 <SEP> $
<tb> ~ <SEP> - <SEP> Yield <SEP> ponberal <SEP> Cg + <SEP> 71.6 <SEP>% <SEP> 72 <SEP>% <SEP> 72.7 <SEP>%
<tb><SEP> - <SEP> Benzene <SEP> 27.5 <SEP>% <SEP> 27.3 <SEP>% <SEP> 26.9 <SEP>%
<tb><SEP> - :: Toluene <SEP> 34.6 <SEP>% <SEP>34> 4 <SEP>% <SEP> 33.8 <SEP>%
<tb><SEP> B <SEP> - <SEP> Benzene <SEP> + <SEP> toluene <SEP> 62.1% <SEP> 61.6 <SEP>% <SEP> 60.7 <SEP>%
<tb><SEP> +
<tb><SEP> - <SEP> - <SEP> Yield <SEP> by weight <SEP> C5 <SEP> 70.4 <SEP> X <SEP> 70.8 <SEP>% <SEP> 71.4 <SEP> X
<Tb>
Example 4

This example relates to the use of the catalyst A of Example 1 for the hydrocracking of a cut distilling between 330 and 610 C, obtained by hydrotreating a vacuum distillate (400-650.degree. gross. This section has the following characteristics
- d415: 0.870
- nitrogen: 5 ppm
The reaction conditions are as follows
- temperature: 380 "C
total pressure: 12 MPa
- speed (vol./vol./hour): 1
- Hydrogen flow rate (vol / vol of hydrocarbons): 1000
The conversion to C1 - Cz is equal to 0.30%.

An effluent consisting of
- fraction C3 - 160 OC, 23,2% of the weight of the load, - fraction 160 - 340 OC, 47>% of the weight of the load,
- fraction greater than 340 OC, 28.9% of the weight of the load.

The fraction 160 - 340 "C constitutes an excellent fuel" Diesel "-:
- "Diesel" index: 73
- cloud point, less than - 30 C,
- freezing point, less than - 63 ° C.

Example 5

This example relates to the use of catalysts according to the invention for isomerization reactions of saturated hydrocarbons
In a stainless steel tubular reactor, 100 g of the catalyst A prepared in Example 1 and previously calcined for one hour in air at 400.degree. C. are placed in a fixed bed.

 The reactor is then flushed with a stream of dry hydrogen at a rate of fifty liters of hydrogen per liter of catalyst per hour, at a temperature of 50 ° C. and at a pressure of 0.2 MPa. using a pump, one liter of solution containing 0.2 mol / liter of AlCl 2 (C 2 H 5) in normal heptane at a rate of 500 cm 3 / h and recycling the effluent from the reactor.

 After eight hours of circulation, the pump is stopped, the solvent is removed and the solid is dried under hydrogen.

 The analysis carried out on the solid halogen shows that it contains 11.7% by weight of chlorine, 0.34% by weight of piatin, 0.21% by weight of hafnium and 0.43% by weight of cadmium. .

 In the tubular reactor previously used, 50 cm 3 of the catalyst thus prepared is placed in a fixed bed. With the reactor kept under hydrogen circulation 150 ° C. and 2 MPa, a hydrocarbon feed containing 50% by weight of normal pentane and 50% by weight of normal hexane is injected, to which 1000 ppm by weight of carbon tetrachloride is added. The feedstock is injected at a rate of two liters per liter of catalyst per hour while maintaining a hydrogen hourly flow rate such that the hydrogen / hydrocarbon ratio is 3 mol / mol.

The analysis of the reactor effluent shows that it has the following composition
isopentane: 28.6% by weight
- normal pentane: 21.4% by weight
- isohexanes: 43.7% by weight
normal hexane: 6.3% by weight so that iC5 / C5 = 57.2% and iC6 / C6 = 87.4%.

Example 6

 This example relates to the use of catalysts according to the invention for the isomerization reactions of aromatic hydrocarbons.

 An alumina catalyst containing 0.4% platinum, 0.25% hafnium, 0.5% cadmium and 10% fluorine is prepared. The catalyst is prepared as in Example 1 using hydrofluoric acid instead of hydrochloric acid. The catalyst thus prepared is used to isomerize in paraxylene a charge of metaxylene: the reaction is carried out at 430 ° C., under a pressure of 1.2 MPa (weight of filler / weight of catalyst and per hour: 5, ratio in moles of hydrogen / hydrocarbons). = 5).

 A paraxylene conversion corresponding to 95.2% of the thermodynamic equilibrium is obtained with a yield by weight of xylenes of 99.9%.

Claims (10)

1 / Catalyst containing a support and, by weight relative to the support, 0.05 to 0.6% of a noble metal of the platinum family, 0.005 to 5% of hafnium, 0.005 to 5% of at least one metal selected from zinc, cadmium and mercury and 0.1 to 15% of a halogen. 2 / Catalyst according to claim 1 containing, by weight relative to the support, 0.1 to 0.5% of a noble metal of the platinum family, 0.01 to 3% of hafnium and 0.05 to 3 Z of at least one metal selected from zinc, cadmium and mercury. 3 / Catalyst according to claim 1 comprising a support and by weight relative to the support 0.1 to 0.5% of a noble metal of the platinum family, 0.05 to 0.4% of hafnium and 0, 08 to 1 Z of at least one metal selected from zinc, cadmium and mercury. 4 / Use of the catalyst according to claim 1 in a hydrocarbon conversion process selected from reforming reactions, aromatic hydrocarbon production, isomerization of paraffinic and aromatic hydrocarbons, hydrocracking, hydrodealkylation and steam dealkylation of aromatic hydrocarbons. 5 / A method according to claim 4 wherein one operates with at least one moving bed of catalyst. 6 / Use of the catalyst according to claim 2 in a reforming process or production of aromatic hydrocarbons, at a temperature between 430 and 600 "C, at a pressure between 0.1 and 3.5 MPa. 7 / Use of the catalyst according to claim 3 in a reforming process or production of aromatic hydrocarbons, at a temperature between 510 and 600 OC, at a pressure between 0.1 and 1.8 MPa with an hourly speed included between 1 and 10 volumes of liquid filler per volume of catalyst, the molar ratio hydrogen ne / hydrocarbons being between 5 and 20, the method of circulating a charge formed of hydrogen and hydrocarbons through at least two zones each of said zones being of the moving catalyst bed type, said charge flowing successively through each reaction zone and the catalyst also flowing successively through each reaction zone flowing from top to bottom in each of them, the said catalyst being withdrawn from each reaction zone to be sent to the next reaction zone, and the catalyst being withdrawn from the last the reaction zone traversed by the charge and sent to an accumulation zone from which the catalyst is sent into a regeneration zone and then into a reduction zone, and then gradually reintroduced into the first reaction zone traversed by the charge.  8. Catalyst according to claim 3, wherein the catalyst contains (a) an alumina support, (b) platinum or iridium, (c) hafnium and (d) cadmium. 9. Catalyst according to claim 3, wherein the catalyst contains (a) an alumina support, (b) platinum or iridium, (c) hafnium and (d) zinc. The use according to claim 6 wherein the conditions. The process procedures are selected to produce a gasoline with a clear octane number greater than or equal to 102.