FR2520257A1 - Reforming catalyst of increased activity and life - contains platinum group metal, tantalum, and copper, silver or gold - Google Patents

Abstract

A catalyst comprises 0.05-0.6 (esp. 0.1-0.5) wt.% of a noble metal of the Pt family, 0.005-3 (esp. 0.1-0.25) wt.% Ta, 0.005-5 (esp. 0.05-2) wt.% of Cu, Ag or Au, 0.1-15 wt.% of a halogen, and a support, pref. Al2O3. Useful in reforming, aromatics prodn., isomerisation of paraffins and aromatic hydrocarbons, hydrocracking, and hydro- and stream-dealkylation of aromatic hydrocarbons. The catalysts have increased activity and esp. increased life. In prodn. of high-octane gasoline, hydrogenolysis is reduced. The benefits are greatest at low pressures, high temps. and long operating times.

Description

The invention relates to novel catalysts for conversion of hydrocarbons.

These catalysts contain a support, a noble metal of the platinum family, tantalum at least one metal selected from copper, silver and gold 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 3.5 MPa, (-, 1 MPa = 1 kg / cm 2) with a hourly rate of between 0.1 and 10 volumes of liquid filler per volume of catalyst, the molar ratio of hydrogen / hydrocarbons 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 novel catalysts is applicable to reforming reactions with a view to obtaining a gasoline with a clear octane number greater than or equal to 102. The severe conditions of the hydroreforming or catalytic hydroreforming reactions are more particularly the following: the average temperature is between about 510 and 580 OC, the pressure is between about 0.5 and 1.8 MPa, preferably 0.6 and 1.3 MPa, the hourly speed is between 1 and 10 volumes of liquid filler per volume of catalyst and the recycle ratio is between 6 and 10 moles of hydrogen per mole of filler. The feedstock is generally a naphtha distilling from about 60 ° C to about 220 ° C, particularly a straight-run naphtha, to aromatic hydrocarbon production reactions from unsaturated or unsaturated species (for the production of benzene, toluene , and xylenes). If the feedstock is unsaturated, i.e. if it contains diolefins and monoolefins, it must first be removed by selective or total hydrogenation.

Subsequently, the charge possibly freed by hydrogenation of substantially all of its diolefins and monoolefins, when it contains them, is subjected to a hydrogen treatment, in the presence of a catalyst, at a temperature of between about 530 and 600 ° C. pressure of between 0.1 and 1.3 MPa, the hourly flow rate of liquid charge 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 to 20. The charge may consist of pyrolysis gasolines, cracking gas, in particular steam-cracking gas, or catalytic reforming gas, or it may also 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. The conversion conditions include a liquid hourly space velocity, or LHSV, or volume per hour of liquid feed at 15 OC per volume of catalyst, from about 0.1 to 10.0, preferably having an upper limit of 4, About 0 and a hydrogen flow rate 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 OC, at a pressure of between about 0.005 and 7 MPa, the hourly volumetric flow rate being between 0.1 and 10 times the volume of catalyst.

The catalysts of the invention are also suitable for the isomerizations in a hydrogen atmosphere of saturated hydrocarbons having 4 to 7 carbon atoms, at a temperature of between 50 and 250 ° C., for example 100 ° -200 ° C. The procedure is preferably carried out under a pressure of 0.5 to 10 MPa with a space velocity of 0.2 to 10 liters of feed per liter of catalyst per hour.
H2 / 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 of water-dealkylation of aromatic hydrocarbons, these reactions being carried out under known operating conditions, generally between 300 and 600 ° C., for for example, to manufacture benzene from toluene or from other alkylbenzenes.

The catalysts can be used in a moving bed, in particular for reforming reactions or for the production of 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. Reaction zones placed side by side are preferably 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 gradually flows up and down this zone from which it is withdrawn progressively downwards, and by any appropriate means (lift in particular in the case of reactors arranged side by side), it is transported upwards. the next reaction zone in which it also progressively flows 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. leaving 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. Continuous racking is preferred over periodic racking.

Catalysts containing a platinum-family metal deposited on a support have been known for a long time. But despite the many improvements which have since been made to these catalysts, for example by the incorporation of one, two or even three other metals chosen from among the most diverse groups of the periodic table of elements, we are still endeavoring today to seek new catalysts which, on the one hand, would give even better yields than those obtained hitherto and which, on the other hand, would also have a longer life than known catalysts. strives to improve the mechanical properties of these catalysts to enable in particular their use in moving bed, in the form of agglomerates, for example beads or extruded, of appreciable size, so as to allow a relatively easy passage to the 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 activity, but especially an increased lifetime, compared to the catalysts of the prior art.

The specific catalyst used in the present invention includes a support, a platinum family noble metal, tantalum and a metal selected from copper, silver and gold and a halogen, for example, chlorine or fluorine. . Preferred noble metals of the platinum family are platinum, rhodium and iridium. The third preferred metal is iron or cobalt.

 The catalyst according to the invention contains, by weight relative to the support (a) 0.05 to 0.6% and more particularly 0.1 to 0.5% of noble metal of the platinum family, (b) 0.005 to 3% , preferably 0.05 to 0.4% and more particularly 0.1 to 0.25% of tantalum (c) 0.005 to 5%, preferably 0.02 to 3% and more particularly 0.05 to 2% of copper or gold or silver (d) 0.1 to 15% by weight, based on the carrier, of a halogen, for example chlorine or fluorine.

The supports are generally chosen from the oxides of metals of groups II, III and / or IV of the periodic table of elements such as, for example, oxides of magnesium, aluminum, titanium, zirconium, thorium or silicon. , taken alone or mixed with one another 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, etc., as well as the mixtures of metal oxides of the X and Y type. groups II, III and / or IV with zeolite material.

For aromatic hydrocarbon reforming or production reactions and isomerization reactions of paraffinic or aromatic hydrocarbons, the preferred carrier is alumina; the specific surface area of the alumina may advantageously be between 50 and 600 m 2 per gram, preferably between 80 and 400 m 2 / g.

The catalyst can be prepared according to the conventional methods of impregnating the support by means of solutions of compounds of the constituents which it is desired to introduce. One uses either a common solution of these constituents, or distinct solutions for each component. 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 400 and 1000 OC, preferably in the presence of free oxygen, for example by conducting an air sweep.

Examples of metal compounds used in the composition of the catalyst include, for example, 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 CCl 4, CH 2 Cl 2, or CH 3 Cl, etc.

Tantalum, it will be introduced by a method that aims to avoid at the time of impregnation of alumina, the hydrolysis of the chemical species containing the tantalum element; freshly prepared tantalic acid is prepared by means of a suitable complexing agent, this complexing agent possibly being, for example, an acetylacetonate or diaminotetraacetic acid or a polycarboxylic acid, this polycarboxylic acid possibly being an organic polyacid such as, for example, for example, oxalic acid, tartaric acid, citric acid and malic acid. (It may be possible to facilitate the complexation of tantalic acid with the aid of an oxidizing agent, such as, for example, hydrogen peroxide). The solution then serves to impregnate the chosen alumina. Next, the mixture is dried at a temperature generally of between 100 and 130 ° C., for approximately 2 to 15 hours, and is then calcined at a temperature generally of between 400 and 750 ° C., for approximately 1 to 15 hours, then is reduced to a temperature between 250 and 800 OC for about 1 to 10 hours.

(The freshly prepared tantalic acid, which is complexed with a suitable complexing agent, may be obtained from a tantalum salt (for example, from a tantalum chloride or a tantalate of an alkali metal) which is hydrolyzed in an aqueous medium (by means of a base such as for example ammonia, if it uses a salt such as tantalum chloride, or by means of an acid, such as for example hydrochloric acid, if a salt such as alkaline tantalate is used) The hydrated tantalum oxide precipitates, washed and redissolved in the chosen complexing agent).

Then follow a second impregnation using a solution containing the platinum family metal and the metal selected from copper, silver and gold.

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. Many attempts at metal association have been made and recently catalytic compositions having up to 4 and even 5 metals have been seen.

These compositions have certainly provided an improvement but genera lly, if the promoters used provide good stability characteristics, they also bring unfortunately, especially if it is noble metals of the platinum family, a certain tendency to hydrogenolysis, which ultimately leads to a decrease in yields and a shortening of the cycle time and the possible number of cycles, that is to say, a decrease in the life of the catalyst.

However, the simultaneous use of tantalum and copper (or tantalum and silver, or tantalum and gold) together with a noble metal of the platinum family, very clearly attenuates this state of affairs by significantly reducing this amount. hydrogenolysing tendency, and it has been found that the benefits provided by each of the three constituents are optimal in the case of severe operating conditions especially at 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 equal to 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% by weight
- number of octane "clear research" ........ about 37
- average molecular weight ............. 110
- density at 20 OC ........................ 0,782
This naphtha passes with recycled hydrogen on two catalysts A and
B containing 0.4% platinum and 0.2% tantalum by weight relative to the support which is an alumina having a surface area of 240 m 2 / g and a pore volume of 0.57 cm 3 / g; the chlorine content of catalysts A and B is 1.12%. Catalyst A additionally contains 0.5% copper and catalyst B additionally contains 0.5% silver (by weight with respect to the carrier). ).

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 ClH (d = 1.19)
20 g of an aqueous solution of chloroplatinic acid containing 2% by weight of platinum
- 10 cm of a solution containing 0.2 g of tantalum in the form of trioxaltantalic acid [Ta O (C204) 3 H3]
and 1.9 g of copper nitrate trihydrate for catalyst A
or 0.79 g of silver nitrate for catalyst B
It is left in contact for 6 hours, filtered off and dried for 2 hours at 80 ° C. and then calcined at 540 ° C. in dry air (drying of the air with activated alumina). Then reduced under a current of dry hydrogen (activated alumina) for 2 hours at 445 C. The catalysts A and B obtained contain
- 0.4 Z platinum
- 0.2% tantalum
0.5% copper (catalyst A) or 0.5% silver (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.

The operation is continuous, in a moving bed, in three reactors of substantially identical volumes.

The operating conditions are as follows
pressure: 1 MPa
- 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 indicates 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 several months for example, operating as indicated, that is to say, that is, continuously, in the 3-bed moving-bed system, the catalyst being withdrawn, for example continuous, at a speed set so that the entire catalyst bed of the reactor is progressively renewed by the fresh catalyst, for example, in about 500 hours.

Example 2

Example 1 was repeated with catalysts containing platinum, copper tantalum or silver and the contents of tantalum, copper or silver were varied.

the metal contents and the results obtained are given in Table II. All of these catalysts contain 1.12% chlorine.

Example 3
Catalysts A and B prepared in Example 1 are used in a process for producing aromatic hydrocarbons.

These two catalysts are passed through with hydrogen a charge of the following composition by weight
TABLE 1

<tb><SEP> Cata <SEP> Yield <SEP> Gas <SEP> recy
<tb><SEP> Metal <SEP>% <SEP> by <SEP> report <SEP> at <SEP> support
<tb> ly- <SEP> C5 + <SEP> clage <SEP>% <SEP> H2
<tb><SEP> of <SEP> Catalyst
<tb> seur <SEP> (weight) <SEP> (molar)
<tb><SEP> A <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 80.0 <SEP> 79.7
<tb><SEP> F <SEP> 0.4 <SEP> platinum <SEP> O <SEP> - <SEP> - <SEP> 73.4 <SEP> 72.9
<tb><SEP> C <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 73.7 <SEP> 73.1
<tb><SEP> D <SEP> 0.4 <SEP> Platinum <SEP> 0 <SEP> - <SEP> 0.5 <SEP> Copper <SEP> 76.6 <SEP> 76.1
<tb><SEP> B <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 79.9 <SEP> 79.7
<tb><SEP> E <SEP> 0.4 <SEP> platinum <SEP> 0 <SEP> - <SEP> 0.5 <SEP> silver <SEP> 75.5 <SEP> 75.2
<tb><SEP> G <SEP> 0.4-Platinum <SEP> 0.2 <SEP> Iridium <SEP> 0.5 <SEP> Copper <SEP> 79.6 <SEP> 78.5
<tb><SEP> H <SEP> 0.4 <SEP> Platinum <SEP> 0.08 <SEP> Iridium <SEP> 0.5 <SEP> Copper <SEP> 79.7 <SEP> 78.5
<tb><SEP> I <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> iridium <SEP> 0.5 <SEP> silver <SEP> 79.6 <SEP> 78.5
<tb><SEP> J <SEP> 0.4 <SEP> platinum <SEP> 0.087 <SEP> iridium <SEP> 0.5 <SEP> silver <SEP> 79.7 <SE> 78.5
<tb><SEP> K <SEP> 0.4 <SEP> platinum <SEP> 0.08 <SEP> iridium <SEP> - <SEP> 75.2 <SEP> 74.9
<tb><SEP> L <SEP> 0.4 <SEP> platinum <SEP> 0.08 <SEP> ruthenium <SEP> - <SEP> 75.1 <SEP> 74.9
<tb><SEP> M <SEP> 0.4 <SEP> platinum <SEP> 0.2 <SEP> ruthenium <SEP> - <SEP> 75.1 <SEP> 74.7
<tb><SEP> N <SEP> 0.4 <SEP> platinum <SEP> 0.08 <SEP> ruthenium <SEP> 0.3 <SEP> Copper <SEP> 79.7 <SEP> 78.8
<tb><SEP> O <SEP> 0.4 <SEP> Platinum <SEP> - <SEP> 0.3 <SEP> Copper <SEP> 76.5 <SEP> 76.0
<Tb>
TABLE 2

<tb><SEP> Cata <SEP> Yield <SEP> Gas <SEP> recy
<SEP> Metal <SEP>% <SEP> with <SEP> report <SEP> at <SEP> support
<tb><SEP> ly- <SEP> C5 + <SEP> clage <SEP>% <SEP> H2
<tb> of <SEP> Catalyst
<tb><SEP> seur <SEP> (weight) <SEP> (molar)
<tb><SEP> A1 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.003 <SEP> Copper <SEP> 73.7 <SEP> 73.1
<tb><SEP> A2 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.01 <SEP> Copper <SEP> 79.5 <SEP> 78.5
<tb><SEP> A3 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.04 <SEP> Copper <SEP> 79.9 <SEP> 79.6
<tb><SEP> A <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 80.0 <SEP> 79.7
<tb><SEP> A4 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 2.5 <SEP> Copper <SEP> 79.9 <SEP> 79.6
<tb><SEP> A5 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 4.0 <SEP> Copper <SEP> 79.4 <SEP> 78.4
<tb><SEP> A6 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 6.0 <SEP> Copper <SEP> 73.6 <SEP> 73.0
<tb><SEP> B1 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.003 <SEP> Silver <SEP> 73.7 <SEP> 73.1
<tb><SEP> B2 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.01 <SEP> Silver <SEP> 77.7 <SEQ> 77.5
<tb><SEP> B3 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.04 <SEP> Silver <SEP> 79.8 <SEP> 79.5
<tb><SEP> B <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 79.9 <SEP> 79.7
<tb><SEP> B4 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 2.5 <SEP> Silver <SEP> 79.9 <SEP> 79.6
<tb><SEP> B5 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 4.0 <SEP> silver <SEP> 77.6 <SEP> 77.4
<tb><SEP> B6 <SEP> 0.4 <SEP> Platinum <SEP> 0.2 <SEP> Tantalum <SEP> 6.0 <SEP> Silver <SEP> 73.5 <SEP> 73.1
<tb><SEP> P1 <SEP> 0.4 <SEP> Platinum <SEP> 0.003 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 76.6 <SEP> 76.1
<tb><SEP> P2 <SEP> 0.4 <SEP> Platinum <SEP> 0.003 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 75.5 <SEP> 75.2
<tb><SEP> P3 <SEP> 0.4 <SEP> Platinum <SEP> 0.01 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 78.2 <SEP> 77.8
<tb><SEP> P4 <SEP> 0.4 <SEP> Platinum <SEP> 0.01 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 78.1 <SEP> 77.7
<tb><SEP> P5 <SEP> 0.4 <SEP> Platinum <SEP> 0.08 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 79.8 <SEQ> 78.6
<tb><SEP> P6 <SEP> 0.4 <SEP> Platinum <SEP> 0.08 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 79.8 <SEP> 79.5
<tb><SEP> P7 <SEP> 0.4 <SEP> Platinum <SEP> 0.3 <SEP> Tantalum <SEP> 0.5 <SEP> Copper <SEP> 78.1 <SEP> 77.7
<tb><SEP> P8 <SEP> 0.4 <SEP> Platinum <SEP> 0.3 <SEP> Tantalum <SEP> 0.5 <SEP> Silver <SEP> 78.0 <SEP> 77.5
<Tb>
- isopentane + n.pentane ............... 1.59%
- isohexanes + n.hexane ............... 24,22%
- isoheptanes + n.heptane .............. 42.55 Z
- cyclopentane ...................... 0,13%
- methylcyclopentane ................ 6.72%
- cyclohexane ....................... 5.50%
- # naphthenes in C7 .................. 15,81%
- # naphthenes in C8 .................. 0,14%
- benzene ........................... 1.68%
- toluene ........................... 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, which indicates, according to the age of the catalyst, the weight contents of benzene, toluene, benzene + toluene, relative to the initial charge, as well as the weight yield C5.
TABLE 3

<tb> Cata <SEP> Composition <SEP> Age <SEP> of <SEP> catalyst- <SEP> 30 <SEP> hours <SEP> 200 <SEP> hours <SEP> 400 <SEP> hours
<tb><SEP> will weight <SEP> the <SEP> seur <SEP> in
<tb><SEP> of the <SEP> product <SEP> \ <SEP> hours
<tb><SEP> - <SEP> benzene <SEP> 27.2 <SEP> Z <SEP> 26.8 <SEP> Z <SEP> 1 <SEP> 26.3 <SEP> Z
<tb> A <SEP> - <SEP> toluene <SEP> 35.6 <SEP> Z <SEP>. <SEP> 35.2 <SE> Z <SE> 34.7 <SE> Z
<tb><SEP> - <SEP> benzene <SEP> + <SEP> toluene <SEP> 62.8 <SEP> Z <SEP> 1 <SEP> 62.0 <SEP> Z <SEP> I <SEP> 61.0 <SEP>%
<tb><SEP> - <SEP> Yield <SEP> by weight <SEP> C <SEP> + <SEP> 71.8 <SEP> Z <SEP> 72.3 <SEP> Z <SEP> 72.9 <SEP> Z
<tb><SEP> 5
<tb><SEP> - <SEP> Benzene <SEP> 27.6 <SEP> Z <SEP> 27.2 <SEP> Z <SEP> 26.9 <SEP> Z
<tb><SEP> - <SEP> - <SEP> toluene <SEP> 34.7 <SEP> Z <SEP> 34.2 <SEP> Z <SEP> - <SEP> 33.8 <SEP> Z
<tb> B <SEP> - <SEP> benzene <SEP> + <SEP> toluene <SEP> 62.3 <SEP> Z <SEP> 61.6 <SE> Z <SEP> 60.7 <SE> Z
<tb><SEP> +
<tb><SEP> - <SEP> yield <SEP> weight <SEP> C5 <SEP> 70.7 <SEP> Z <SEP> 70.9 <SE> Z <SE> 71.7 <SE> Z
<Tb>
Example 4
This example relates to the use of catalyst A of Example 1 for the hydrocracking of a cut distilling between 330 and 610 OC, obtained by hydrotreating a vacuum distillate (400 - 650 C) of crude oil. This section has the following characteristics
- d45: 0.870
4
- 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 - C2 is equal to 0.30%.

An effluent consisting of - fraction C3 - 160 OC, 23.7% by weight of feedstock - fraction 160 - -340 OC, 47.9% by weight of feedstock - fraction greater than 340 OC, 28.4% is obtained. the weight of the load
The fraction 160 - 340 OC constitutes an excellent fuel "Diesel",
- "Diesel" index: 73
- cloud point, less than - 30 OC
- freezing point, less than - 63%
Example 5
This example relates to the use of catalysts according to the invention for the 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 ° 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 two absolute bars. After which, one liter of solution containing 0.2 mol / l of AlCl 2 (C 2 H 5) in normal heptane is injected with the aid of a pump, at a rate of 500 cm 3 / h, and by recycling the reactor effluent. .

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 halogenated solid shows that it contains 11.7% by weight of chlorine, 0.34% by weight of platinum, 0.17% by weight of tantalum and 0.43% by weight of copper.

In the tubular reactor previously used, it has, in bed
3
fixed, 50 cm of the catalyst thus prepared. The reactor being maintained
under the circulation of hydrogen at 150 OC and 2 MPa, a charge is injected
hydrocarbon containing 50% by weight of normal pentane and 50% by weight
weight of normal hexane to which 1000 ppm by weight of
carbon tetrachloride. The charge is injected at the rate of two
liters per liter of catalyst per hour while maintaining a flow rate
hydrogen schedule such that the hydrogen / hydrocarbon ratio is
of 3 moles / mole.

The analysis of the reactor effluent shows that it has the composi
following
- isopentane: 28.6% by weight
- normal pentane: 21.4% by weight
- isohexanes: 43.8% by weight
- normal hexane: 6.2% by weight so that iC5 / C5 = 57.2% and iC6 / C6 = 87.6%
Example 6
This example relates to the use of catalysts according to the invention for isomerization reactions of aromatic hydrocarbons.

An alumina catalyst containing 0.4% platinum, 0.2% tantalum, 0.5% copper 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: one operates at 430 OC, under a pressure of 1.2 MPa (weight of charge per weight of catalyst and per hour = 5; ratio in moles hydrogen / hydrocarbons = 5).

A conversion to paraxylene corresponding to 95.3% of the thermodynamic equilibrium is obtained with a yield by weight of xylenes of 99.9%.

Claims (7)

1 / Catalyst containing a support and, in weight relative to the sup  port, 0.05 to 0.6% of a noble metal of the platinum family, 0.005  at 3% tantalum, 0.005 to 5% of a metal selected from copper,  silver and gold and 0.1 to 15% of a halogen. 2 / Catalyst according to claim 1 containing, by weight by rap  support, 0.1 to 0.5% of a noble metal of the family of  platinum, 0.05 to 0.4% tantalum and 0.02 to 3% of a chosen metal  among copper, silver and gold. 3 / Catalyst according to claim 1 containing a support and in  weight relative to the support 0.1 to 0.5% of a noble metal of the  Platinum family, 0.1 to 0.25% tantalum, 0.05 to 2% metal  chosen from copper, silver and gold.  Catalyst according to claim 3, wherein the catalyst  contains (a) an alumina support (b) platinum or iridium  (c) tantalum and (d) copper.  5 / Catalyst according to claim 3, wherein the catalyst  contains (a) an alumina support (b) platinum or iridium  (c) tantalum and (d) money. 6 / Use of the catalyst according to claim 1 in a process  of hydrocarbon conversion selected from the refor reactions  mage, aromatic hydrocarbon production, isomerization  paraffinic and aromatic hydrocarbons, hydrocracking,  hydrodealkylation and dealkylation with water vapor of hydro  aromatic carbides.  7 / A method according to claim 6 in which one operates with at least  a moving bed of catalyst. 8 / Use of the catalyst according to claim 2 in a process  reforming or producing aromatic hydrocarbons at a  temperature between 430 and 6000 C under pressure  between 0.1 and 3.5 M Pa.  9 / The use of the catalyst according to claim 3 in a process  reforming or producing aromatic hydrocarbons at a  temperature between 510 and 6000 C, under a pressure of  between 0.1 and 1.8 M Pa with a speed  be 1 and 10 volumes of liquid charge per volume of catalyst,  the hydrogen / hydrocarbon molar ratio being between 5  and 20, the method of circulating a shaped charge  of hydrogen and hydrocarbons through at least two zones of  reaction arranged in series, each zone being of type to bed  mobile catalyst, the said charge circulating successively to  through each reaction zone and the circulating catalyst equal  mentally through each reaction zone in  from top to bottom in each of them, the said catalyst being  withdrawn from each reaction zone to be sent to the zone  of the next reaction, then the catalyst being withdrawn from the  last reaction zone crossed by the load and sent in  an accumulation zone from which the catalyst is  sent into a regeneration zone, then into a re-zone  then gradually reintroduced into the first zone  reaction through which the charge passes. 10 / A method according to claim 8 wherein the conditions ope  are chosen so as to produce a species of index  clear octane greater than or equal to 102.