WO2022117414A1

WO2022117414A1 - Izm-2 catalyst containing aluminium and gallium and use thereof in the isomerisation of long paraffinic feedstocks to middle distillates

Info

Publication number: WO2022117414A1
Application number: PCT/EP2021/082847
Authority: WO
Inventors: Raquel Martinez-Franco; Christophe Bouchy; Ana Marta COSTA
Original assignee: IFP Energies Nouvelles
Priority date: 2020-12-01
Filing date: 2021-11-24
Publication date: 2022-06-09
Also published as: FR3116737A1; FR3116737B1

Abstract

The invention relates to a catalyst comprising at least one metal from group VIII of the periodic table, at least one matrix and at least one IZM-2 zeolite containing both aluminium and gallium, said IZM-2 zeolite having a molar ratio between the number of moles of silicon and the number of moles of aluminium and gallium Si/(AI+Ga) of between 35 and 175 and a molar ratio between the number of moles of gallium and the number of moles of aluminium and gallium Ga/(Ga+AI) of between 0.10 and 0.90, and to the method for isomerisation of paraffinic feedstocks using said catalyst.

Description

CATALYST BASED ON IZM-2 CONTAINING ALUMINUM AND GALLIUM AND ITS USE FOR THE ISOMERIZATION OF LONG PARAFFINIC CHARGERS INTO MIDDLE DISTILLATES

FIELD OF THE INVENTION

In order to meet the demand for middle distillate bases, that is to say in a cut that can be incorporated into the kerosene and/or diesel pool, various methods for producing middle distillates based on the use of oil, natural gas or even renewable resources can be implemented.

Middle distillate bases can thus be produced from a paraffinic feedstock obtained from a feedstock derived from renewable sources, and in particular vegetable oils or animal fats, raw or having undergone a prior treatment, as well as the mixtures of such fillers. Indeed, said fillers from renewable sources contain chemical compounds of the triglyceride type or esters of fatty acids or free fatty acids, the structure and the length of the hydrocarbon chain of these compounds being compatible with the hydrocarbons present in the middle distillates. Said fillers from renewable sources produce, after hydrotreatment, paraffinic fillers, free of sulfur compounds and aromatic compounds. These paraffinic fillers are typically composed of linear paraffins having a number of carbon atoms between 9 and 25.

Middle distillate bases can also be produced from natural gas, coal, or renewable sources through the Fischer-Tropsch synthesis process. In particular, the so-called low temperature Fischer-Tropsch synthesis using cobalt catalysts makes it possible to produce essentially linear paraffinic compounds having a very variable number of carbon atoms, typically from 1 to 100 carbon atoms or even more. Separation steps can make it possible to recover paraffinic feedstocks composed of linear paraffins having a number of carbon atoms between 9 and 25.

However, these middle distillate bases obtained after hydrotreatment of vegetable oils or after the low-temperature Fischer-Tropsch synthesis process generally cannot be incorporated as such into the kerosene or gas oil pool, in particular because of insufficient cold properties. Indeed, high molecular weight paraffins which are linear or very weakly branched and which are present in these middle distillate bases lead to high pour points and therefore to congealing phenomena for uses at low temperatures. For example, the pour point of a linear hydrocarbon containing 20 carbon atoms per molecule and whose boiling point equals approximately 340°C, i.e. typically included in the middle distillate cut, is +37°C approximately which makes it impossible to use, the specification being -15°C for diesel. In order to decrease the values of the pour points, these linear or very slightly branched paraffins must be completely or partially eliminated.

This operation can be carried out by extraction with solvents such as propane or methyl ethyl ketone, one then speaks of dewaxing with propane or methyl ethyl ketone (MEK). However, these techniques are costly, time-consuming and not always easy to implement.

The selective cracking of the longest linear paraffinic chains, which leads to the formation of compounds of lower molecular weight, part of which can be eliminated by distillation, constitutes a solution for reducing the values of the pour points. Given their shape selectivity, zeolites are among the most widely used catalysts for this type of process. The most widely used catalyst in the dewaxing by selective cracking category is ZSM-5 zeolite, of MFI structural type, which has three-dimensional porosity, with medium pores (opening at 10 oxygen atoms 10MR). However, the cracking caused in such processes leads to the formation of large quantities of products of lower molecular weights than those targeted, such as butane, propane, ethane and methane, which considerably reduces the yield of desired products.

Another solution for improving cold resistance consists in isomerizing long linear paraffins while minimizing cracking as much as possible. This can be achieved by the implementation of hydroisomerization process employing bifunctional catalysts. Bifunctional catalysts involve a Bronsted acid phase (for example a zeolite) and a hydro/dehydrogenating phase (for example platinum) and generally a matrix (for example alumina). The appropriate choice of the acid phase makes it possible to promote the isomerization of long linear paraffins and to minimize cracking. Thus the shape selectivity of one-dimensional medium-pore zeolites (10MR) such as ZSM-22, ZSM-23, NU-10, ZSM-48, ZBM-30 zeolites makes their use particularly suitable for obtaining catalysts that are selective towards isomerization. . These examples illustrate the ongoing research carried out to develop ever more efficient catalysts for the isomerization of long linear paraffins, minimizing the formation of cracking products by using appropriate zeolites. Zeolites are crystallized microporous solids consisting of [MeC] tetrahedra, in which Me can be a 4-valence element such as silicon, or a 3-valence element such as aluminum. Tetrahedra containing an element of valence 3 therefore carry a negative charge which is neutralized by a metallic or organic cation or a proton. When said cation is a proton, a Bronsted acid site is generated. It is reported in the literature that all other things being equal, the strength of the acid Bronsted site depends on the nature of the element of valence 3. Generally the strength of the acid Bronsted sites decreases in the order: Si(OH )Al > Si(OH)Ga > Si(OH)Fe > Si(OH)ln > Si(OH)B (see H. Berndt, A. Martin, H. Kosslick, B. Lücke, Microporous Materials, vol. 2 , No. 3, pp. 197-204, 1994 or M. Guisnet, FR Ribeiro, “zeolites, a nanoworld at the service of catalysis”, EDP Sciences, 2006). It is generally accepted that the decrease in the strength of the Bronsted acid sites promotes isomerization selectivity, all other things being equal. The replacement of aluminum by gallium, iron, indium or boron could thus make it possible to further improve the isomerization selectivity of a given zeolite structure. Patent US9,758,734,B2 thus teaches a paraffinic charge isomerization process with a catalyst containing ZSM-12, ZSM-22, ZSM-23, ZSM-48, ZSM-57 or MCM-22 zeolite in which at least part of the aluminum is replaced by iron. The comparative examples illustrate the gain in selectivity obtained with catalysts using ZSM-23 containing iron compared with a catalyst using ZSM-23 containing only aluminum, in addition to silicon. However, the use of an iron-containing zeolite instead of aluminum leads to a loss of catalyst activity of 30°C, which is in agreement with weaker Bronsted sites in the iron-containing zeolite. . Recently Liu et al reported the synthesis of ZSM-22 zeolites containing aluminum (AI-ZSM-22) or aluminum and gallium (Ga-AI-ZSM-22) and their catalytic evaluation in hydroconversion of n-dodecane. All the bifunctional catalysts implementing Ga-Al-ZSM-22 zeolites are more selective in isomerization than the catalyst implementing the Al-ZSM-22 zeolite. Catalysts using Ga-Al-ZSM-22 zeolites are all the more selective in isomerization as the Ga/Al molar ratio is high. On the other hand, all the bifunctional catalysts implementing Ga-AI-ZSM-22 zeolites are less active than the catalyst implementing the AI-ZSM-22 zeolite, with a loss of activity of between 10 and 30°C. Catalysts implementing Ga-Al-ZSM-22 zeolites are all the less active in isomerization as the Ga/Al molar ratio is high. In the studies mentioned, the total or partial replacement of the aluminum by another element such as iron or gallium in the zeolite therefore makes it possible to improve the isomerization selectivity of the catalyst, but to the detriment of its catalytic activity.

However, in addition to the selectivity towards the isomerization, the activity of the catalyst is also an important parameter. Increasing the activity of the catalyst makes it possible to improve the overall operation of the process from the point of view of its productivity or its energy consumption. It is therefore desirable to develop catalysts that are as active and as selective as possible towards isomerization.

Recently, the Applicant in her work has developed a new zeolite, IZM-2 zeolite as described in application FR 2 918 050 A, as well as a process for converting paraffinic feedstocks comprising long paraffins having a number of carbon atoms between 9 and 25 using a catalyst comprising said IZM-2 zeolite as described in patent application FR 2 984 911 A, said process making it possible to improve the selectivity towards the production of middle distillate base in limiting the production of light cracked products that cannot be incorporated into a diesel and/or kerosene pool.

FR 2 918 050 A discloses an IZM-2 solid having an overall silicon to aluminum Si/Al molar ratio of between 1 and infinity, and preferably between 25 and 312. In the illustrative example of patent application FR 2 984 911 A, only an IZM-2 solid having an overall Si/Al molar ratio of 53 is used in the catalyst formulation. This overall Si/AI molar ratio was calculated from the X-ray fluorescence characterization results.

Patent application FR 3 082 521 A1 discloses a process for the isomerization of paraffinic fillers using a catalyst comprising at least one metal from group VIII of the periodic table of elements, at least one matrix and at least one IZM-2 zeolite , in which the ratio between the number of moles of silicon and the number of moles of aluminum of the network of the IZM-2 zeolite is between 25 and 55.

Patent application FR 3 074428 A1 teaches a process for preparing a bifunctional catalyst comprising an acid function consisting of IZM-2 zeolite, as well as its use in a process for the isomerization of a paraffinic feed having a number of carbon atoms between 9 and 25.

In all the illustrative examples of the patents mentioned, the IZM-2 zeolite used in the catalysts is in the aluminosilicate form, that is to say that the zeolite contains aluminum and silicon. Elements such as gallium, iron, indium, boron are not present.

The research work carried out by the applicant led him to discover that, surprisingly, a specific catalyst based on an IZM-2 zeolite containing both gallium and aluminum makes it possible to obtain an improved activity. of the catalyst while maintaining maximum isomerization selectivity when the latter is used in a process for the isomerization of a paraffinic feedstock

In particular, the use of such a catalyst in the isomerization process according to the invention leads to optimal catalytic performance in terms of activity and selectivity. Such a catalyst is substantially more selective than a catalyst comprising an IZM-2 zeolite containing only aluminum and it is significantly more active than a catalyst comprising an IZM-2 zeolite containing only gallium.

An object of the present invention relates to a bifunctional catalyst comprising at least one metal from group VIII of the periodic table of the elements, at least one matrix and at least one IZM-2 zeolite containing both aluminum and gallium, said zeolite having a Si/(Al+Ga) molar ratio of between 35 and 175 and a Ga/(Al+Ga) molar ratio of between 0.10 and 0.90.

Another object of the present invention relates to a process for the isomerization of paraffinic fillers, preferably derived from hydrotreated vegetable and/or animal oils or from the low-temperature Fischer-Trospch synthesis, said process implementing said bifunctional catalyst.

OBJECT OF THE INVENTION

The present invention relates to a catalyst comprising at least one metal from group VIII of the periodic table of elements, at least one matrix and at least one IZM-2 zeolite containing both aluminum and gallium, said IZM-2 zeolite having a molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) between 35 and 175, preferably between 40 and 150, preferably between 50 and 135 and very preferably between 55 and 120, and a molar ratio between the number of moles of gallium and the number of moles of aluminum and gallium Ga/(Ga+Al) between 0.10 and 0.90, preferably between 0.20 and 0.80 and very preferably between 0.35 and 0.65 .

The present invention also relates to a process for isomerizing a paraffinic feed comprising paraffins having a number of carbon atoms between

9 and 25, said paraffinic feed being produced from renewable resources, said process operating at a temperature between 200°C and 500°C, at a pressure between 0.45 MPa and 7 MPa, at an hourly space velocity of between between 0.1 and

10 h′ ¹ , expressed in kilograms of charge introduced per kilogram of catalyst and per hour, in the presence of hydrogen and at a partial pressure of hydrogen of between 0.3 and 5.5 MPa, and implementing the catalyst according to the invention.

Within the meaning of the present invention, the ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) of the IZM-2 zeolite and the ratio between the number of moles of gallium and the number of moles of aluminum and gallium Ga/(Ga+Al) of the IZM-2 zeolite is calculated from the silicon, aluminum and gallium contents in the IZM-2 zeolite. The silicon content is measured by X-ray fluorescence, and the aluminum and gallium contents are measured by inductively coupled plasma.

An advantage of the present invention is to provide a specific catalyst based on an IZM-2 zeolite containing, in addition to silicon, both aluminum and gallium and having a molar ratio Ga/(Ga+Al) optimized and a process for the isomerization of a paraffinic charge using said catalyst making it possible to improve the selectivity of the catalyst while maintaining maximum activity.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, the present invention relates to a catalyst comprising at least one metal from group VIII of the periodic table of the elements, at least one matrix and at least one IZM-2 zeolite containing both aluminum and gallium. , said IZM-2 zeolite having a molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) of between 35 and 175, preferably between 40 and 150, preferably between 50 and 135 and very preferably between 55 and 120, and a molar ratio between the number of moles of gallium and the number of moles of aluminum and gallium Ga/(Ga+Al) of between 0.10 and 0.90, preferably between 0, 20 and 0.80 and very preferably between 0.35 and 0.65.

Catalyst

In accordance with the invention, the catalyst comprises at least one metal from group VIII of the periodic table of the elements, at least one matrix and at least one IZM-2 zeolite containing both aluminum and gallium, said IZM zeolite -2 having a Si/(Al+Ga) molar ratio of between 35 and 175, preferably between 40 and 150 and preferably between 50 and 135 and very preferably between 55 and 120 and a Ga/(Ga +AI) between 0.10 and 0.90, preferably between 0.20 and 0.80 and very preferably between 0.35 and 0.65.

Advantageously, said at least matrix and said at least zeolite containing both aluminum and gallium constitute a support for the metallic phase comprising said at least one group VIII metal.

IZM-2 zeolite

In accordance with the invention, the catalyst comprises the IZM-2 zeolite containing both aluminum and gallium, in particular denoted Ga-Al-IZM-2.

The catalyst advantageously comprises from 1 to 90% by weight, preferably from 3 to 85% by weight, more preferably from 4 to 80% by weight and even more preferably from 6 to 70% by weight of Ga-Al-IZM- 2.

Ga-AI-IZM-2 zeolite is a crystallized microporous solid having a crystalline structure described in patent application FR 2 918 050. Ga-AI-IZM-2 zeolite has an X-ray diffraction diagram including at least the lines listed in table 1. Preferably, the X diffraction diagram does not contain other lines of significant intensity (that is to say of intensity greater than about three times the background noise) than those listed in table 1.

This diffraction diagram is obtained by X-ray crystallographic analysis using a diffractometer using the conventional powder method with the Kai radiation of copper (λ=1.5406 Å). From the position of the diffraction peaks represented by the angle 20, the characteristic reticular equidistances dhki of the sample are calculated by Bragg's relation. The measurement error A(dhki) on dhki is calculated using Bragg's relation as a function of the absolute error A(20) assigned to the measurement of 20. An absolute error A(20) equal to ± 0.02 ° is commonly accepted. The relative intensity l _rei assigned to each value of dhki is measured according to the height of the corresponding diffraction peak. The X-ray diffraction diagram of the Ga-AI-IZM-2 zeolite according to the invention comprises at least the lines at the dhki values given in table 1. In the dhki column, the average values of the inter-distance distances are indicated. -reticulars in Angstroms (Â). Each of these values must be affected by the measurement error A(dhki) of between ± 0.6 Å and ± 0.01 Å.

Table 1: Mean dhki values and relative intensities measured on an X-ray diffraction pattern of the calcined Ga-AI-IZM-2 crystalline solid.

Mean dhki values and relative intensities measured on an X-ray diffraction pattern of a calcined Ga/AI-IZM-2 zeolite where FF = very strong; F = strong; m = medium; mf = medium low; f = low; ff = very weak.

The relative intensity I _rei is given in relation to a relative intensity scale where a value of 100 is assigned to the most intense line of the X-ray diffraction diagram: ff<15;15<f<30;30<mf<50;50<m<65;65<F<85; FF > 85.

In accordance with the invention, said catalyst comprises at least one IZM-2 zeolite containing both aluminum and gallium, having a Si/(Al+Ga) molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium of the IZM-2 zeolite comprised between 35 and 175, preferably between 40 and 150 and more preferably between 50 and 135 and very preferably between 55 and 120 and such that the molar ratio between the number of moles of gallium and the number of moles of aluminum and gallium Ga/(Ga+Al) of the IZM-2 zeolite is between 0.1 and 0.9, of preferably between 0.2 and 0.8 and very preferably between 0.35 and 0.65.

According to the invention, the ratio of the number of moles of silicon divided by the number of moles of aluminum and gallium of the IZM-2 zeolite (Si/(Al+Ga)) is calculated according to the formula:

Si/(AI+Ga) = n _Si / (n _A i+n _Ga )

And the ratio of the number of moles of gallium divided by the number of moles of gallium and aluminum of the IZM-2 zeolite (Ga/(Al+Ga)) is calculated according to the formula:

Ga/(Al+Ga) = n _Ga / (n _A i+n _Ga ) with nsi / (n _A i+n _Ga ): ratio of the number of moles of silicon divided by the number of moles of aluminum and gallium , in mole/mole, n _Ga / (n _A i+n _Ga ): ratio of the number of moles of gallium divided by the number of moles of aluminum and gallium, in mole/mole, nsi: moles of silicon per gram of the zeolite, in mole/gram, n _Al : moles of aluminum per gram of zeolite, in mole/gram, n _Ga : moles of gallium per gram of zeolite, in mole/gram.

The number of moles of silicon per gram of IZM-2 zeolite is determined from the percentage (%) weight (wt) of silicon in the zeolite according to the formula: n _Si = (% wtSi) / [MM(Si) * 100 ] with nsi: moles of silicon per gram of zeolite, in mole/gram, %pdsSi: weight percentage of silicon in the zeolite (dry mass), measured by X-ray fluorescence by bead assay on a PANalytical brand AXIOS device working at 125 mA and 32 kV,

MM(Si): molar mass of silicon, in grams/mole.

The number of moles of aluminum per gram of IZM-2 zeolite is determined from the percentage (%) weight (wt) of aluminum in the zeolite according to the formula: n _Ai = (% wtAI) / [MM(AI) * 100] with n _Ai : moles of aluminum per gram of zeolite, in mole/gram,

%wdsAI: weight percentage of aluminum in the zeolite (dry mass), measured by inductively coupled plasma (ICP) on a SPECTRO ARCOS ICP-OES device from SPECTRO according to the ASTM D7260 method,

MM(AI): molar mass of aluminium, in grams/mole,

The number of moles of gallium per gram of IZM-2 zeolite is determined from the percentage (%) weight (wt) of gallium of the zeolite according to the formula: n _Ga = (% wtGa) / [MM(Ga) * 100 ] with n _Ga : moles of galium per gram of zeolite, in mole/gram,

%wtGa: weight percentage of gallium in the zeolite (dry mass), measured by inductively coupled plasma (ICP) on a SPECTRO ARCOS ICP-OES device from SPECTRO according to the ASTM D7260 method,

MM(Ga): molar mass of galium, in grams/mole,

More specifically, the preparation of a Ga-Al-IZM-2 zeolite is carried out according to the following steps. Step i)

At least one source of a tetravalent element X in the oxide form XO2, X being silicon, at least one mixture of two sources of trivalent elements in the oxide form Y2O3, Y being aluminum and gallium, is mixed in an aqueous medium, at least one nitrogenous organic compound 1,6-bis(methylpiperidinium)hexane dibromide RBr2, at least one source of at least one alkali metal and/or alkaline-earth metal M of valence n.

The reaction mixture preferably has the following molar composition:

SiO2/(Al2O3+Ga2O3) between 70 and 350, preferably between 80 and 300,

Ga2O3/(Al2O3+Ga2C>3) between 0.01 and 0.99, preferably between 0.05 and 0.95, preferably between 0.10 and 0.90, preferably between 0.20 and 0 .80 and very preferably between 0.35 and 0.65,

H2O/SiO2 between 1 to 100, preferably from 10 to 70,

RBr2/SiO2 between 0.02 and 2, preferably from 0.05 to 0.5,

M ₂ /nO/SiO ₂ between 0.005 and 1, preferably 0.005 and 0.5,

In the molar composition of the above reaction mixture:

SiO2 designates the molar quantity of SiO2 provided by the source(s) of silicon,

AI2O3 designates the molar quantity of AI2O3 provided by the aluminum source(s),

Ga2Û3 designates the molar quantity of Ga2Û3 provided by the source(s) of gallium,

H2O is the molar amount of water in the mixture,

RBr2 denotes the molar amount of 1,6-bis(methylpiperidinium)hexane dibromide

M2O denotes the molar quantity, expressed in oxide form, of one or more alkali metal(s) and/or alkaline-earth metal(s) chosen from lithium, sodium, potassium, calcium, magnesium and the mixture of at least two of these metals, very preferably M is sodium.

Step i) makes it possible to obtain a precursor gel. Step ii)

The hydrothermal treatment of said precursor gel obtained at the end of step i) at a temperature of between 150° C. and 195° C., for a period of between 1 day (i.e. 24 hours) and 4 days (i.e. 96 hours) and preferably between 1 day (ie 24 hours) and 3 days (ie 72 hours) until said Ga-Al-IZM-2 zeolite crystallizes.

The reaction is generally carried out with stirring or without stirring, preferably with stirring.

At the end of the reaction, after carrying out said step ii) of the preparation process according to the invention, the solid phase formed of a Ga-Al-IZM-2 zeolite is preferably filtered, washed and then dried.

After the drying step, the crystallized material, advantageously composed of Ga-Al-IZM-2 zeolite, is ready for subsequent steps such as calcination and/or ion exchange. For these steps, all the conventional methods known to those skilled in the art can be used.

The dried zeolite can then be advantageously calcined, preferably at a temperature of between 450 and 700° C. for a period of between 2 and 20 hours, the calcination possibly being preceded by a gradual rise in temperature.

The Ga-AI-IZM-2 zeolite obtained at the end of the calcination step is devoid of any organic species and in particular of the organic structurant RBr2. The calcined Ga-AI-IZM-2 zeolite is generally analyzed by X-ray diffraction.

In accordance with the invention, the Si/(Al+Ga) molar ratio and the Ga/(Al+Ga) molar ratio of the IZM-2 zeolite obtained can also be adjusted to the desired values by post-treatment methods for the zeolite. Ga-Al-IZM-2 obtained after synthesis. Such methods are known to those skilled in the art, and make it possible to carry out dealumination, degalliation or desilication of the zeolite. Preferably, the Si/(Al+Ga) molar ratio of the IZM-2 zeolite entering into the composition of the catalyst according to the invention is adjusted by an appropriate choice of the composition of the synthesis gel (step i)) of said zeolite . The Ga-Al-IZM-2 zeolite present in the catalyst according to the invention is very advantageously in its acid form, that is to say in the protonated H ⁺ form. In such a case, it is advantageous that the ratio of the number of moles of cations other than the proton per gram of Ga-Al-IZM-2 zeolite divided by the number of moles of aluminum and gallium per gram of IZM- 2 is less than 0.9, preferably less than 0.6 and very preferably less than 0.3. To do this, the Ga-Al-IZM-2 zeolite entering into the composition of the catalyst according to the invention can for example be exchanged by at least one treatment with a solution of at least one ammonium salt so as to obtain the ammonium form of the Ga-AI-IZM-2 zeolite which, once calcined, leads to the acid form of said Ga-AI-IZM-2 zeolite. This exchange step can be carried out at any step in the preparation of the catalyst, that is to say after the step for preparing the Ga-Al-IZM-2 zeolite, after the step for shaping the Ga-Al-IZM-2 zeolite with a matrix, or else after the step of introducing the hydro-dehydrogenating metal. Preferably, the exchange step is carried out before the step of shaping the IZM-2 zeolite.

Matrix

According to the invention, said catalyst comprises at least one matrix. Said matrix can advantageously be amorphous or crystallized.

Preferably, said matrix is advantageously chosen from the group formed by alumina, silica, silica-alumina, clays, titanium oxide, boron oxide and zirconia, taken alone or as a mixture or else aluminates can also be chosen. Preferably, alumina is used as the matrix. Preferably, said matrix contains alumina in all its forms known to those skilled in the art, such as for example alpha, gamma, eta, delta type aluminas. Said aluminas differ by their specific surface and their porous volume. The mixture of the matrix and the shaped Ga-Al-IZM-2 zeolite constitutes the catalyst support.

Said catalyst advantageously comprises from 10 to 99% by weight, preferably from 15 to 97% by weight, more preferably from 20 to 96% by weight and even more preferably from 30 to 94% by weight of said matrix.

metallic phase

In accordance with the invention, the catalyst comprises at least one group VIII metal preferably chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum, alone or as a mixture preferably chosen from the noble metals of group VIII, very preferably chosen from palladium and platinum and even more preferably platinum.

Preferably, said catalyst comprises a group VIII metal content of between 0.01 and 5% by weight relative to the total mass of said catalyst and preferably between 0.1 and 4% by weight.

In the case where said catalyst comprises at least one noble metal from group VIII, the noble metal content of said catalyst is advantageously between 0.01 and 5% by weight, preferably between 0.1 and 4% by weight and very preferably between 0.1 and 2% by weight relative to the total mass of said catalyst.

The dispersion of the group VIII metal(s), determined by chemisorption, for example by H2/O2 titration or by chemisorption of carbon monoxide, is between 10% and 100%, preferably between 20% and 100% and even more preferably between 30% and 100%. The macroscopic distribution coefficient of the group VIII metal(s), obtained from its (their) profile determined by Castaing microprobe, defined as the ratio of the concentrations of the group VIII metal(s) to heart of the grain relative to the edge of this same grain, is between 0.7 and 1.3, preferably between 0.8 and 1.2. The value of this ratio, close to 1, testifies to the homogeneity of the distribution of the group VIII metal(s) in the catalyst.

Said catalyst may advantageously comprise at least one additional metal chosen from the group formed by the metals of groups IIIA, IVA and VI IB of the periodic table of the elements and preferably chosen from gallium, indium, tin and rhenium. . Said additional metal is preferably chosen from indium, tin and rhenium. In this case, the content of metal chosen from metals of groups IIIA, IVA and VI IB is preferably between 0.01 and 2%, preferably between 0.05 and 1% by weight relative to the total mass of said catalyst. .

Preparation of the catalyst

The catalyst according to the invention can advantageously be prepared according to all the methods well known to those skilled in the art. Step i) formatting of the support

In accordance with the invention, the method comprises a step i) of preparing the catalyst support by shaping the Ga-Al-IZM-2 zeolite with a matrix so that the weight percentage of the zeolite is advantageously between 1 and 90% based on the weight of the support, preferably from 3 to 85% and more preferably from 4 to 80% and even more preferably from 6 to 70% by weight.

The catalyst support used in the process according to the invention can advantageously be shaped by any technique known to those skilled in the art. The shaping can advantageously be carried out, for example, by extrusion, by pelleting, by the drop coagulation method (“oil-drop”), by granulation on a turntable or by any other method well known to those skilled in the art. . The supports thus obtained can be in different shapes and sizes. Advantageously, the various constituents of the support or of the catalyst can be shaped by mixing step to form a paste then extrusion of the paste obtained, or else by mixing powders then pelletizing, or else by any other known method of agglomeration of a powder containing alumina. The supports thus obtained can be in different shapes and sizes. Preferably, the shaping is carried out by kneading and extrusion.

During the shaping of the support by kneading then extrusion, said Ga-Al-IZM-2 zeolite can be introduced during the dissolution or suspension of the compounds of the matrix, in particular alumina, or precursors of the matrix, in particular of alumina such as boehmite for example. Said Ga-Al-IZM-2 zeolite can be, without this being limiting, for example in the form of powder, ground powder, suspension, suspension having undergone a deagglomeration treatment. Thus, for example, said zeolite can advantageously be suspended acidulated or not at a concentration adjusted to the final content of Ga-Al-IZM-2 targeted in the catalyst according to the invention. This suspension commonly called a slurry is then mixed with the compounds of the matrix, in particular alumina or precursors of the matrix, in particular alumina.

Furthermore, the use of additives can advantageously be implemented to facilitate shaping and/or improve the final mechanical properties of the supports, as is well known to those skilled in the art. By way of example of additives, mention may be made in particular of cellulose, carboxymethyl-cellulose, carboxy-ethyl-cellulose, tall oil (tall oil), xanthan gums, surfactants, flocculants such as polyacrylamides, carbon black, starches, stearic acid, polyacrylic alcohol, polyvinyl alcohol, biopolymers, glucose, polyethylene glycols, etc

It is advantageous to add or remove water to adjust the viscosity of the paste to be extruded. This step can advantageously be carried out at any stage of the mixing step.

To adjust the solid matter content of the paste to be extruded in order to make it extrudable, it is also possible to add a predominantly solid compound and preferably an oxide or a hydrate. A hydrate is preferably used and even more preferably an aluminum hydrate. The loss on ignition of this hydrate is advantageously greater than 15%.

The extrusion of the paste resulting from the mixing step can advantageously be carried out by any conventional tool, commercially available. The paste resulting from the mixing is advantageously extruded through a die, for example using a piston or a single or double extrusion screw. The extrusion can advantageously be carried out by any method known to those skilled in the art.

The catalyst supports according to the invention are generally in the form of cylindrical or polylobed extrudates such as bilobed, trilobed, polylobed in a straight or twisted shape, but can optionally be manufactured and used in the form of crushed powders, tablets, rings, balls and/or wheels. Preferably, the catalyst supports according to the invention have the form of spheres or extrudates. Advantageously, the support is in the form of extrudates with a diameter of between 0.5 and 5 mm and more particularly between 0.7 and 2.5 mm. The shapes may be cylindrical (which may or may not be hollow) and/or twisted cylindrical and/or multilobed (2, 3, 4 or 5 lobes for example) and/or rings. The multilobed shape is advantageously used in a preferred manner. ii) Drying

The support thus obtained can then be subjected to a drying step. Said drying step is advantageously carried out by any technique known to those skilled in the art.

Preferably, the drying is carried out under air flow. Said drying can also be carried out under a flow of any oxidizing, reducing or inert gas. Preferably, the drying is advantageously carried out at a temperature between 50 and 180°C, preferably between 60 and 150°C and very preferably between 80 and 130°C. iii) Calcination

Said support, optionally dried, then preferably undergoes a calcining step.

Said calcination step is advantageously carried out in the presence of molecular oxygen, for example by carrying out an air sweep, at a temperature advantageously greater than 200° C. and less than or equal to 1100° C. Said calcination step can advantageously be carried out in a traversed bed, in a licked bed or in a static atmosphere. For example, the kiln used can be a rotating rotary kiln or be a vertical kiln with radial traversed layers. Preferably, said calcining step is carried out between more than one hour at 200°C to less than one hour at 1100°C. The calcination can advantageously be carried out in the presence of water vapor and/or in the presence of an acid or basic vapor. For example, calcination can be carried out under partial pressure of ammonia. iv) Post-calcination treatments

Post-calcination treatments can optionally be carried out, so as to improve the properties of the support, in particular the textural properties.

Thus, the catalyst support used in the process according to the present invention can be subjected to a hydrothermal treatment in a confined atmosphere. By hydrothermal treatment in a confined atmosphere is meant a treatment by passage through an autoclave in the presence of water at a temperature above ambient temperature, preferably above 25°C, preferably above 30°C.

During this hydrothermal treatment, the support can advantageously be impregnated, prior to its passage through the autoclave (the autoclaving being carried out either in the vapor phase or in the liquid phase, this vapor or liquid phase of the autoclave possibly being acid or not). This impregnation, prior to the autoclaving, can advantageously be acidic or not. This impregnation, prior to autoclaving, can advantageously be carried out dry or by immersing the support in an acidic aqueous solution. By dry impregnation is meant bringing the support into contact with a volume of solution less than or equal to the total pore volume of the support. Preferably, the impregnation is carried out dry. The autoclave is preferably a rotating basket autoclave such as that defined in patent application EP 0 387 109 A. The temperature during the autoclaving can be between 100 and 250° C. for a period of time between 30 minutes and 3 hours. v) Deposition of the metallic phase

For the deposition of the metal from group VIII of the periodic table of the elements, all the deposition techniques known to those skilled in the art and all the precursors of such metals may be suitable. It is possible to use deposition techniques by dry impregnation or in excess of a solution containing the precursors of the metals, in the presence of competitors or not. The metal can be introduced at any stage in the preparation of the catalyst: on the Ga/Al-IZM-2 zeolite and/or on the matrix, in particular before the shaping stage, during the shaping, or after the shaping step, on the catalyst support. Preferably, the metal is deposited after the shaping step.

The control of certain parameters implemented during the deposition, in particular the nature of the precursor of the group VIII metal(s) used, makes it possible to direct the deposition of said metal(s). ux) mainly on the matrix or on the zeolite.

Thus, to introduce the group VIII metal(s), preferably platinum and/or palladium, mainly on the matrix, it is possible to implement an anion exchange with hexachloroplatinic acid and/or hexachloropalladic acid, in the presence of a competing agent, for example hydrochloric acid, the deposition generally being followed by calcination, for example at a temperature of between 350 and 550° C. and for a period of between 1 and 4 hours. With such precursors, the group VIII metal(s) is (are) deposited mainly on the matrix and said metal(s) exhibit(s) good dispersion and good macroscopic distribution through the catalyst grain.

It is also possible to envisage depositing the group VIII metal(s), preferably platinum and/or palladium, by cationic exchange so that the said metal(s) )t deposited mainly on the zeolite. Thus, in the case of platinum, the precursor can for example be chosen from:

- ammonia compounds such as salts of platinum (II) tetramines of formula Pt(NH ₃ ) ₄ X ₂ , salts of platinum (IV) hexamines of formula Pt (NH ₃ ) ₆ X ₄ ; platinum (IV) salts halopentamines of formula (PtX(NH ₃ ) ₅ )X ₃ ; N-tetrahalogenodiamine platinum salts of formula PtX ₄ (NH ₃ ) ₂ ; and

- halogenated compounds of formula H(Pt(acac) ₂ X);

X being a halogen chosen from the group formed by chlorine, fluorine, bromine and iodine, X preferably being chlorine, and "acac" representing the acetylacetonate group (of structural formula C ₅ H ₇ O ₂ ), derivative of acetylacetone. With such precursors, the group VIII metal(s) is (are) deposited mainly on the zeolite and said metal(s) exhibit(s) good dispersion and good macroscopic distribution through the catalyst grain.

In the case where the catalyst of the invention also contains at least one metal chosen from the metals of groups IIIA, IVA and VI I B, all the techniques for depositing such a metal known to those skilled in the art and all the precursors of such metals may be suitable.

The metal(s) of group VIII and that(those) of groups I HA, IVA and VI IB can be added, either separately or simultaneously in at least one unitary step. When at least one Group I HA, IVA and VI IB metal is added separately, it is preferred that it be added after the Group VIII metal.

The additional metal chosen from metals from groups II IA, IVA and VI IB can be introduced via compounds such as, for example, the chlorides, bromides and nitrates of metals from groups I HA, IVA and VII B. example in the case of indium, nitrate or chloride is advantageously used and in the case of rhenium, perrhenic acid is advantageously used. The additional metal chosen from the metals of groups IIIA, IVA and VI IB can also be introduced in the form of at least one organic compound chosen from the group consisting of the complexes of the said metal, in particular the polyketone complexes of the metal and the hydrocarbyl metals such as metal alkyls, cycloalkyls, aryls, alkylaryls and arylalkyls. In the latter case, the introduction of the metal is advantageously carried out using a solution of the organometallic compound of said metal in an organic solvent. It is also possible to employ organohalogen compounds of the metal. As organic metal compounds, mention may be made in particular of tetrabutyltin, in the case of tin, and triphenylindium, in the case of indium. If the additional metal chosen from metals of groups IIIA, IVA and VIIB is introduced before the metal of group VIII, the compound of metal IIIA, IVA and/or VIIB used is generally chosen from the group consisting of the halide, the nitrate , acetate, tartrate, carbonate and oxalate of the metal. The introduction is then advantageously carried out in aqueous solution. But it can also be introduced using a solution of an organometallic compound of the metal, for example tetrabutyltin. In this case, before proceeding with the introduction of at least one group VIII metal, a calcination in air will be carried out.

In addition, intermediate treatments such as for example calcination and/or reduction can be applied between the successive depositions of the different metals.

Before its use in the process according to the invention, the catalyst is preferably reduced. This reduction step is advantageously carried out by a treatment under hydrogen at a temperature of between 150° C. and 650° C. and a total pressure of between 0.1 and 25 MPa. For example, a reduction consists of a plateau at 150°C for two hours then a rise in temperature to 450°C at the rate of 1°C/min then a plateau for two hours at 450°C; throughout this reduction step, the hydrogen flow rate is 1000 normal m ³ of hydrogen per tonne of catalyst and the total pressure is kept constant at 0.2 MPa. Any ex-situ reduction method can advantageously be considered. A preliminary reduction of the final catalyst ex situ, under a stream of hydrogen, can be implemented, for example at a temperature of 450° C. to 600° C., for a period of 0.5 to 4 hours.

Said catalyst also advantageously comprises sulfur. In the case where the catalyst of the invention contains sulfur, the latter can be introduced at any stage of the preparation of the catalyst: before or after the shaping stage, and/or drying and/or calcination, before and/or after the introduction of the metal(s) mentioned above, or alternatively by sulfurization in situ and or ex-situ before the catalytic reaction. In the case of in situ sulfurization, the reduction, if the catalyst has not been previously reduced, takes place before the sulfurization. In the case of ex situ sulphurization, reduction and then sulphurization are also carried out. The sulfurization is preferably carried out in the presence of hydrogen using any sulfurizing agent well known to those skilled in the art, such as for example dimethyl sulphide or hydrogen sulphide.

The catalysts according to the invention come in different shapes and sizes. They are generally used in the form of cylindrical and/or polylobed extrudates such as bi-lobed, tri-lobed, poly-lobed in straight and/or twisted shape, but can optionally be manufactured and used in the form of crushed powders, tablets, rings, balls and/or wheels. Preferably, the catalysts used in the process according to the invention have the form of spheres or extrudates. Advantageously, the catalyst is in the form of extrudates with a diameter of between 0.5 and 5 mm and more particularly between 0.7 and 2.5 mm. The shapes may be cylindrical (which may or may not be hollow) and/or twisted cylindrical and/or multilobed (2, 3, 4 or 5 lobes for example) and/or rings. The multilobed shape is advantageously used in a preferred manner. The deposition of the metal does not change the shape of the support.

Said catalyst according to the invention more preferably comprises, and preferably consists of:

- from 1 to 90% by weight, preferably from 3 to 85% by weight and more preferably from 4 to 80% by weight and even more preferably from 6 to 70% by weight of the Ga-Al-IZM-2 zeolite according to invention,

- 0.01 and 5% by weight, preferably between 0.1 and 4% by weight and very preferably between 0.1 and 2% by weight of at least one noble metal from group VIII of the periodic table elements, preferably platinum,

- optionally from 0.01 to 2%, preferably from 0.05 to 1% by weight of at least one additional metal chosen from the group formed by the metals of groups 11 IA, IVA and VI IB,

- optionally a sulfur content, preferably such that the ratio of the number of moles of sulfur to the number of moles of group VIII metal(s) is between 0.3 and 3,

- at least one matrix, preferably alumina, ensuring the complement to 100% by weight in the catalyst.

Another object of the invention relates to a process for the isomerization of paraffinic fillers having a number of carbon atoms between 9 and 25, said paraffinic filler being produced from renewable resources, or by a process involving a step recovery by the Fischer-Tropsch route, said process operating at a temperature of between 200°C and 500°C, at a pressure of between 0.45 MPa and 7 MPa, at an hourly space velocity of between 0.1 and 10 kilogram of load introduced by kilogram of catalyst and per hour, in the presence of hydrogen at a partial pressure of hydrogen of between 0.3 and 5.5 MPa, and implementing the catalyst according to the invention.

The isomerization process

In accordance with the invention, the process for isomerizing a paraffinic feedstock comprising paraffins having a number of carbon atoms between 9 and 25, said paraffinic feedstock being produced from renewable resources, is implemented at a temperature between 200°C and 500°C, at a pressure between 0.45 MPa and 7 MPa, at an hourly space velocity between 0.1 and 10 kilograms of charge introduced per kilogram of catalyst and per hour and in the presence of hydrogen, at a hydrogen partial pressure of between 0.3 and 5.5 MPa. Preferably, said process is carried out at a temperature between 200 and 450°C, and more preferably between 220 and 430°C. The pressure at which the method according to the invention is implemented is preferably between 0.6 and 6 MPa. Preferably, the method is implemented at an hourly space velocity advantageously between 0.2 and 7 h ⁻¹ and preferably between 0.5 and 5 h ⁻¹ .

According to the invention, the isomerization process comprises bringing a paraffinic feed into contact with at least said catalyst according to the invention present in a catalytic reactor, in the presence of hydrogen. The hydrogen partial pressure is between 0.3 and 5.5 MPa, preferably between 0.4 and 4.8 MPa.

The paraffins of said paraffinic charge have a number of carbon atoms comprised between 9 and 25, preferably comprised between 10 and 25 and very preferably between 10 and 22. The paraffin content in said charge implemented in the process according to the invention is advantageously greater than 90% by weight, preferably greater than 95% by weight, even more preferably greater than 98% by weight. Within said paraffins, the mass percentage of isoparaffins is less than 15%, preferably less than 10% and very preferably less than 5%.

According to the invention, said paraffinic filler used in the process according to the invention can be produced from renewable resources.

According to a first embodiment, said paraffinic filler is produced from renewable resources chosen from vegetable oils, algae or algal oils, fish oils and fats of vegetable or animal origin, or mixtures of such fillers.

Said vegetable oils can advantageously be raw or refined, totally or partly, and derived from plants chosen from rapeseed, sunflower, soy, palm, olive, coconut, copra, castor, cotton , peanut, linseed and crambe oils and all oils derived, for example, from sunflower or rapeseed by genetic modification or hybridization, this list not being exhaustive. Said animal fats are advantageously chosen from lard and fats composed of residues from the food industry or from catering industries. Frying oils, various animal oils such as fish oils, tallow, lard can also be used.

In this embodiment, the renewable resources from which the paraffinic filler used in the process according to the invention is produced essentially contain chemical structures of the triglyceride type which those skilled in the art also know under the name fatty acid triester as well as free fatty acids, whose fatty chains contain a number of carbon atoms between 9 and 25.

The structure and length of the hydrocarbon chain of the latter is compatible with the hydrocarbons present in diesel and kerosene, i.e. the middle distillate cut. A fatty acid triester is thus composed of three chains of fatty acids. These fatty acid chains in the form of triesters or in the form of free fatty acids, have a number of unsaturations per chain, also called the number of carbon-carbon double bonds per chain, generally between 0 and 3 but which can be higher in particular for oils derived from algae which generally have a number of unsaturations per chain of 5 to 6.

The molecules present in said renewable resources that can be used in the present invention therefore have a number of unsaturations, expressed per molecule of triglyceride, advantageously between 0 and 18. In these fillers, the level of unsaturation, expressed as a number of unsaturation per hydrocarbon fatty chain, is advantageously between 0 and 6.

Renewable resources generally also include various impurities and in particular heteroatoms such as nitrogen. Nitrogen levels in oils plants are generally between 1 ppm and 100 ppm by weight approximately, depending on their nature. They can reach up to 1% weight on particular loads.

Said paraffinic filler used in the process according to the invention is advantageously produced from renewable resources, in particular chosen from vegetable oils, algae or algal oils, fish oils and fats of vegetable or animal origin, or mixtures thereof, according to methods known to those skilled in the art. One possible route is the catalytic transformation of said renewable resources into deoxygenated paraffinic effluent in the presence of hydrogen and, in particular, hydrotreating.

Preferably, said paraffinic feedstock is produced by hydrotreating said renewable resources. These processes for hydrotreating renewable resources are already well known and are described in numerous patents. By way of example, said paraffinic feedstock used in the process according to the invention can advantageously be produced, preferably by hydrotreatment then by gas/liquid separation, from said renewable resources as for example in patent FR 2 910 483 or in patent FR 2 950 895.

According to a second embodiment, said paraffinic filler used in the process according to the invention can also be a paraffinic filler produced by a process involving a step of upgrading by the Fischer-Tropsch route. In the Fischer-Tropsch process, synthesis gas (CO+H2) is catalytically transformed into oxygenates and essentially linear hydrocarbons in gaseous, liquid or solid form. Said products obtained can constitute the paraffinic charge of the process according to the invention. The synthesis gas (CO+H2) is advantageously produced from natural gas, coal, biomass, any source of hydrocarbon compounds or a mixture of these sources. Thus, the paraffinic feedstocks obtained, according to a Fischer-Tropsch synthesis process, from a synthesis gas (CO+H2) produced from renewable resources, natural gas or coal can be used in the process according to 'invention. Preferably, said paraffinic filler produced by Fischer-Tropsch synthesis and used in the process according to the invention mainly comprises n-paraffins. Thus, said filler comprises an n-paraffin content greater than 60% by weight relative to the total mass of said filler. Said charge may also comprise a content of oxygenated products, preferably less than 10% by weight, a content of unsaturates, that is to say preferably of olefinic products, preferably less than 20% by weight and a content of iso-paraffins preferably less than 10% by weight relative to the total mass of said filler.

Preferably, said paraffinic feed produced by Fischer-Tropsch synthesis is free of heteroatomic impurities such as, for example, sulfur, nitrogen or metals.

LIST OF FIGURES

Figure 1 represents the X-ray diffraction diagram performed on the calcined solid of Example 3.

Figure 2 represents a Scanning Electron Microscope (SEM) snapshot of the solid of Example 3.

EXAMPLES

The following examples illustrate the invention without however limiting its scope.

Example 1 (not in accordance with the invention): preparation of catalyst A

Synthesis of a Ga-IZM-2 zeolite

51.9 g of an aqueous solution of 1,6-bis(methylpiperidinium)hexane dibromide (19.06% by weight) are mixed with 25.778 g of deionized water. 1.684 g of sodium hydroxide (98% by weight, Aldrich) are added to the previous mixture, the preparation obtained is kept under stirring for 10 minutes. Subsequently, 0.489 g galium nitrate (Ga(NOs)3 XH2O), 99% trace metals basis, Sigma-Aldrich) are incorporated and the synthesis gel is kept stirred for 15 minutes. In the end, 20.169 g of colloidal silica (Ludox HS40, 40% by weight, Aldrich) are incorporated into the synthesis mixture which is kept under stirring for half an hour to evaporate the solvent until the composition of the desired precursor gel is obtained. , i.e. a molar composition of the following mixture: 60 SiO2: 0.25 Ga2O3: 10 RBr2: 10 Na2O: 2000 H2O, i.e. a SiO2/Ga2O3 ratio of 240. The precursor gel is then transferred, after homogenization , in a 160 mL stainless steel reactor equipped with a stirring system with four inclined blades. The reactor is closed, then heated for 72 hours with a temperature rise ramp of 3° C./min up to 170° C. with stirring at 300 rpm. The crystallized product obtained is filtered, washed with deionized water, then dried overnight at 100°C. The loss on fire PAF of the dried solid is 3.28%. The solid is then introduced into a muffle furnace where a calcination step is carried out: the calcination cycle includes a rise of 1.5°C/min in temperature up to 200°C, a plateau at 200°C maintained for 2 hours, a rise of 1° C./min in temperature up to 550° C. followed by a plateau at 550° C. maintained for 8 hours then a return to ambient temperature. The calcined solid product was analyzed by X-ray diffraction and identified as consisting of a Ga-IZM-2 zeolite of greater than 99.8% purity. The solid thus obtained is then put under reflux for 2 hours in an aqueous solution of ammonium nitrate (10 ml of solution per gram of solid, ammonium nitrate concentration of 3 M) in order to exchange the sodium alkali cations with ammonium ions. This refluxing step is carried out four times, then the solid is filtered, washed with deionized water and dried in an oven overnight at 100°C. Finally, to obtain the zeolite in its protonic (acid) form, a calcination step is carried out at 550°C for ten hours (temperature rise ramp of 5°C/min) in a bed traversed under dry air (2 normal liters per hour and per gram of solid). The solid thus obtained was analyzed by X-ray diffraction and identified as consisting of Ga-IZM-2 zeolite. Characterizations by X-ray fluorescence and ICP give access to the following results for the Ga-IZM-2 zeolite:

- ratio of the number of moles of silicon divided by the number of moles of aluminum and gallium, in mol/mol, Si/(Al+Ga): 62;

- ratio of the number of moles of gallium divided by the number of moles of aluminum and gallium, in mol/mol, Ga/(Al+Ga): 1;

- ratio of the number of moles of sodium divided by the number of moles of aluminum and gallium, in mol/mol, Na/(Al+Ga): 0.06.

platinum deposit

The platinum is deposited by impregnation in excess of GGD200 alumina balls (supplied by the company AXENS) with an aqueous solution containing hexachloroplatinic acid. The concentration of hexachloroplatinic acid in the solution is 2.38×10 ⁻² mol/l. 20 grams of alumina are used, the pore volume of which is filled with distilled water and the solid is left to mature for one hour at ambient temperature. The solid is then immersed in 90 ml of a solution of hydrochloric acid HCl with a concentration of 2.13 10' ¹ mol/l in an Erlenmeyer flask then the whole is stirred on a stirring table (100 revolutions/min ) at room temperature for one hour. The hydrochloric acid solution is then withdrawn then the solid is immersed in 90 ml of the hexachloroplatinic acid solution described above then the whole is stirred on a stirring table (100 rpm) at room temperature for 24 hours. The impregnation solution is then drawn off and the solid is rinsed with 160 ml of distilled water. The solid is then dried in a ventilated oven overnight at 110° C. and a calcining step is finally carried out under a flow of dry air (2 normal liters per hour and per gram of solid) in a tube furnace under the conditions following:

- rise in temperature to ambient at 500°C at 5°C/min;

- stage of two hours at 500°C;

- ambient descent.

The Pt content measured by FX on the calcined alumina is 1.7% by weight, its dispersion measured by H2/O2 titration is 86%, its distribution coefficient measured by Castaing microprobe 0.99.

Catalyst shaping

Catalyst A is shaped by pelletizing and crushing the Ga-IZM-2 zeolite with alumina impregnated with Pt. the Ga-IZM-2 powder and grinding-screening of the alumina balls impregnated with Pt to obtain a particle size of less than 63 microns. After weighing the masses of solids desired (1 gram of dry mass for each solid), the mechanical mixing (2 grams of dry mass) of the two powders is carried out using a bucket mill for 2 minutes, with a ball and a frequency of 30 Hz. The mixture is then pelletized with a hydraulic press (4 ton metric) then ground and sieved to a particle size of 250-500 microns.

The composition of catalyst A is as follows: 50% weight Ga-IZM-2/0.85% weight Pt/49.15% weight Alumina. Example 2 (in accordance with the invention): preparation of catalyst B

Synthesis of a Ga-AI-IZM-2 zeolite n°1

This Ga-Al-IZM-2 zeolite was synthesized in accordance with the teaching of patent application FR 2 918 050. 51.892 g of an aqueous solution of 1,6-bis(methylpiperidinium)hexane dibromide (19 .06% by weight) are mixed with 25.892 g of deionized water. 1.676 g of sodium hydroxide (98% by weight, Aldrich) are added to the preceding mixture, the preparation obtained is kept under stirring for 10 minutes. 0.027 g of sodium aluminate (NaAIC>2, 53.00% Al2O3, 42.32% Na2<D, Carlo Erba) are incorporated into the above mixture, the preparation obtained is kept under stirring for 10 minutes. Subsequently, 0.366 g galium nitrate (Ga(NOs)3 XH2O), 99% trace metals basis, Sigma-Aldrich) are incorporated and the synthesis gel is kept stirred for 15 minutes. In the end, 20.167 g of colloidal silica (Ludox HS40, 40% by weight, Aldrich) are incorporated into the synthesis mixture which is kept under stirring for half an hour to evaporate the solvent until the composition of the desired precursor gel is obtained. , i.e. a molar composition of the following mixture: 60 SiO2: 0.063 Al2O3: 0.188 Ga2O3: 10 RBr2: 10 Na2O: 2000 H2O, i.e. a SiO2/(Al2O3+Ga2O3) molar ratio of 240 and a molar ratio Ga2O3/(Al2O3+Ga2O3) of 0.75. The precursor gel is then transferred, after homogenization, into a 160 mL stainless steel reactor equipped with a stirring system with four inclined blades. The reactor is closed, then heated for 72 hours with a temperature rise ramp of 3° C./min up to 170° C. with stirring at 300 rpm. The crystallized product obtained is filtered, washed with deionized water, then dried overnight at 100°C. The loss on ignition PAF of the dried solid is 3.02%. The solid is then introduced into a muffle furnace where a calcination step is carried out: the calcination cycle includes a rise of 1.5°C/min in temperature up to 200°C, a plateau at 200°C maintained for 2 hours, a rise of 1° C./min in temperature up to 550° C. followed by a plateau at 550° C. maintained for 8 hours then a return to ambient temperature. The solid thus obtained is then put under reflux for 2 hours in an aqueous solution of ammonium nitrate (10 ml of solution per gram of solid, ammonium nitrate concentration of 3 M) in order to exchange the sodium alkali cations with ammonium ions. This refluxing step is carried out four times, then the solid is filtered, washed with deionized water and dried in an oven overnight at 100°C. Finally, to obtain the zeolite in its protonic (acid) form, a calcination step is carried out at 550°C for ten hours (temperature rise ramp of 5°C/min) in a bed traversed under dry air (2 normal liters per hour and by gram of solid. The calcined solid product is analyzed by X-ray diffraction and identified as consisting of an IZM-2 zeolite with a purity greater than 99.8%. Characterizations by X-ray fluorescence and ICP give access to the following results for the zeolite Ga-AI-IZM-2 n°1:

- ratio of the number of moles of silicon divided by the number of moles of gallium and aluminum, in mol/mol, Si/(Al+Ga): 68;

- ratio of the number of moles of gallium divided by the number of moles of gallium and aluminum, in mol/mol, Ga/(Al+Ga): 0.73;

- ratio of the number of moles of sodium divided by the number of moles of aluminum and gallium, in mol/mol, Na/(Al+Ga): 0.02.

platinum deposit

The deposition of platinum is carried out in the same way as for catalyst A.

Catalyst shaping

The shaping of the catalyst is the same as for catalyst A.

The composition of catalyst B is as follows: 50% by weight Ga-Al-IZM-2 No. 1/0.85% by weight Pt/49.15% by weight Alumina.

Example 3 (in accordance with the invention): preparation of catalyst C

Synthesis of a zeolite Ga-AI-ZM-2 n°2

This IZM-2 zeolite was synthesized in accordance with the teaching of patent application FR 2 918 050. 51.908 g of an aqueous solution of 1,6-bis(methylpiperidinium)hexane dibromide (19.06% in weight) are mixed with 25.976 g of deionized water. 1.654 g of sodium hydroxide (98% by weight, Aldrich) are added to the preceding mixture, the preparation obtained is kept under stirring for 10 minutes. 0.055 g of sodium aluminate (NaAIO2, 53.00% Al2O3, 42.32% Na2O, Carlo Erba) are incorporated into the above mixture, the preparation obtained is kept stirring for 10 minutes. Subsequently, 0.245 g galium nitrate (Ga(NOs)3 XH2O, 99% trace metals basis, Sigma-Aldrich) are incorporated and the synthesis gel is kept stirred for 15 minutes. In the end, 20.177 g of colloidal silica (Ludox HS40, 40% by weight, Aldrich) are incorporated into the synthesis mixture which is kept under stirring for half an hour to evaporate the solvent until the composition of the desired precursor gel is obtained, that is to say a molar composition of the following mixture: 60 SiC>2: 0.125 Al2O3: 0.125 Ga2O3: 10 RBr2: 10 Na2<D: 2000 H2O, i.e. a SiO2/(Al2O3+Ga2C>3) molar ratio of 240 and a Ga2O3/(Al2O3+Ga2O3) molar ratio of 0.50. The precursor gel is then transferred, after homogenization, into a 160 mL stainless steel reactor equipped with a stirring system with four inclined blades. The reactor is closed, then heated for 72 hours with a temperature rise ramp of 3° C./min up to 170° C. with stirring at 300 rpm. The crystallized product obtained is filtered, washed with deionized water, then dried overnight at 100°C. The loss on ignition PAF of the dried solid is 1.9%. The solid is then introduced into a muffle furnace where a calcination step is carried out: the calcination cycle includes a rise of 1.5°C/min in temperature up to 200°C, a plateau at 200°C maintained for 2 hours, a rise of 1° C./min in temperature up to 550° C. followed by a plateau at 550° C. maintained for 8 hours then a return to ambient temperature. The X-ray diffraction pattern performed on the calcined solid is given in Figure 1. The Scanning Electron Microscope (SEM) photograph is given in Figure 2. The solid thus obtained is then refluxed for 2 hours in an aqueous solution of ammonium nitrate (10 ml of solution per gram of solid, concentration in 3 M ammonium nitrate) to exchange sodium alkali cations for ammonium ions. This refluxing step is carried out four times, then the solid is filtered, washed with deionized water and dried in an oven overnight at 100°C. Finally, to obtain the zeolite in its protonic (acid) form, a calcination step is carried out at 550°C for ten hours (temperature rise ramp of 5°C/min) in a bed traversed under dry air (2 normal liters per hour and per gram of solid). The calcined solid product is analyzed by X-ray diffraction and identified as consisting of a Ga-/Al-IZM-2 zeolite of purity greater than 99.8%. Characterizations by X-ray fluorescence and ICP give access to the following results for the zeolite Ga-AI-IZM-2 n°2:

- ratio of the number of moles of silicon divided by the number of moles of gallium and aluminum, in mol/mol, Si/(Al+Ga): 73;

- ratio of the number of moles of gallium divided by the number of moles of gallium and aluminum, in mol/mol, Ga/(Al+Ga): 0.5;

- ratio of the number of moles of sodium divided by the number of moles of aluminum and gallium, in mol/mol, Na/(Al+Ga): 0.07. platinum deposit

The deposition of platinum is carried out in the same way as for catalyst A.

Catalyst shaping

The shaping of the catalyst is the same as for catalyst A.

The composition of catalyst C is as follows: 50% by weight Ga-Al-IZM-2 No. 2/0.85% by weight Pt/49.15% by weight Alumina.

Example 4 (in accordance with the invention): preparation of catalyst D

Synthesis of a zeolite Ga-AI-IZM-2 n°3

This IZM-2 zeolite was synthesized in accordance with the teaching of patent application FR 2 918 050. 46.023 g of an aqueous solution of 1,6-bis(methylpiperidinium)hexane dibromide (21.50% by weight) are mixed with 31.98 g of deionized water. 1.64 g of sodium hydroxide (98% by weight, Aldrich) are added to the previous mixture, the preparation obtained is kept under stirring for 10 minutes. 0.082 g of sodium aluminate (NaAIC>2, 53.00% Al2O3, 42.32% Na2<D, Carlo Erba) are incorporated into the above mixture, the preparation obtained is kept under stirring for 10 minutes. Subsequently, 0.122 g galium nitrate (Ga(NOs)3 XH2O, 99% trace metals basis, Sigma-Aldrich) are incorporated and the synthesis gel is kept stirred for 15 minutes. In the end, 20.172 g of colloidal silica (Ludox HS40, 40% by weight, Aldrich) are incorporated into the synthesis mixture which is kept under stirring for half an hour to evaporate the solvent until the composition of the desired precursor gel is obtained. , i.e. a molar composition of the following mixture: 60 SiO2: 0.188 Al2O3: 0.063 Ga2O3: 10 RBr2: 10 Na2O: 2000 H2O, i.e. a SiO2/(Al2O3+Ga2O3) molar ratio of 240 and a molar ratio Ga2O3/(Al2O3+Ga2O3) of 0.25. The precursor gel is then transferred, after homogenization, into a 160 mL stainless steel reactor equipped with a stirring system with four inclined blades. The reactor is closed, then heated for 72 hours with a temperature rise ramp of 3° C./min up to 170° C. with stirring at 300 rpm. The crystallized product obtained is filtered, washed with deionized water, then dried overnight at 100°C. The loss on ignition PAF of the dried solid is 0.8%. The solid is then introduced into a muffle furnace where a calcination step is carried out: the calcination cycle includes a rise of 1.5°C/min in temperature up to 200°C, a plateau at 200°C maintained for 2 hours, a rise of 1°C/min in temperature up to 550°C followed by a plateau at 550°C maintained for 8 hours then a return to ambient temperature. The solid thus obtained is then put under reflux for 2 hours in an aqueous solution of ammonium nitrate (10 ml of solution per gram of solid, ammonium nitrate concentration of 3 M) in order to exchange the sodium alkali cations with ammonium ions. This refluxing step is carried out four times, then the solid is filtered, washed with deionized water and dried in an oven overnight at 100°C. Finally, to obtain the zeolite in its protonic (acid) form, a calcination step is carried out at 550°C for ten hours (temperature rise ramp of 5°C/min) in a bed traversed under dry air (2 normal liters per hour and per gram of solid). The calcined solid product is analyzed by X-ray diffraction and identified as consisting of a Ga-Al-IZM-2 zeolite of purity greater than 99.8%. Characterizations by X-ray fluorescence and ICP give access to the following results for the zeolite Ga-AI-IZM-2 n°3:

- ratio of the number of moles of silicon divided by the number of moles of gallium and aluminum, in mol/mol, Si/(Al+Ga): 77;

- ratio of the number of moles of gallium divided by the number of moles of gallium and aluminum, in mol/mol, Ga/(Al+Ga): 0.25;

- ratio of the number of moles of sodium divided by the number of moles of aluminum and gallium, in mol/mol, Na/(Al+Ga): 0.1.

platinum deposit

The deposition of platinum is carried out in the same way as for catalyst A.

Catalyst shaping

The shaping of the catalyst is the same as for catalyst A.

The composition of catalyst D is as follows: 50% by weight Ga-Al-IZM-2 No. 3/0.85% by weight Pt/49.15% by weight Alumina. Example 5 (not in accordance with the invention): preparation of catalyst E

Synthesis of an AI-IZM-2 zeolite

46.050 g of an aqueous solution of 1,6-bis(methylpiperidinium)hexane dibromide (19.06% by weight) are mixed with 32.107 g of deionized water. 1.62 g of sodium hydroxide (98% by weight, Aldrich) are added to the preceding mixture, the preparation obtained is kept under stirring for 10 minutes. Subsequently, 0.109 g of sodium aluminate (NaAIC>2, 53.00% Al2O3, 42.32% Na2<D, Carlo Erba) are incorporated and the synthesis gel is kept stirred for 15 minutes. In the end, 20.165 g of colloidal silica (Ludox HS40, 40% by weight, Aldrich) are incorporated into the synthesis mixture which is kept under stirring for half an hour to evaporate the solvent until the composition of the desired precursor gel is obtained. , i.e. a molar composition of the following mixture: 60 SiC>2: 0.25 Al2O3: 10 RBr2: 10 Na2<D: 2000 H2O, i.e. a SiO2/AhO3 ratio of 240. The precursor gel is then transferred, after homogenization, into a 160 mL stainless steel reactor equipped with a stirring system with four inclined blades. The reactor is closed, then heated for 72 hours with a temperature rise ramp of 3° C./min up to 170° C. with stirring at 300 rpm. The crystallized product obtained is filtered, washed with deionized water, then dried overnight at 100°C. The PAF of the dried solid is 2.8%. The solid is then introduced into a muffle furnace where a calcination step is carried out: the calcination cycle includes a rise of 1.5°C/min in temperature up to 200°C, a plateau at 200°C maintained for 2 hours, a rise of 1° C./min in temperature up to 550° C. followed by a plateau at 550° C. maintained for 8 hours then a return to ambient temperature. The solid thus obtained is then put under reflux for 2 hours in an aqueous solution of ammonium nitrate (10 ml of solution per gram of solid, ammonium nitrate concentration of 3 M) in order to exchange the sodium alkali cations with ammonium ions. This refluxing step is carried out four times, then the solid is filtered, washed with deionized water and dried in an oven overnight at 100°C. Finally, to obtain the zeolite in its protonic (acid) form, a calcination step is carried out at 550°C for ten hours (temperature rise ramp of 5°C/min) in a bed traversed under dry air (2 normal liters per hour and per gram of solid). The calcined solid product is analyzed by X-ray diffraction and identified as consisting of an AI-IZM-2 zeolite with a purity greater than 99.8%. Characterizations by X-ray fluorescence and ICP provide the following results for the AI-IZM-2 zeolite: - ratio of the number of moles of silicon divided by the number of moles of gallium and aluminum, in mol/mol, Si/(Al+Ga): 90;

- ratio of the number of moles of gallium divided by the number of moles of gallium and aluminum, in mol/mol, Ga/(Al+Ga): 0;

- ratio of the number of moles of sodium divided by the number of moles of gallium and aluminum, in mol/mol, Na/(Al+Ga): 0.07.

platinum deposit

The deposition of platinum is carried out in the same way as for catalyst A.

Catalyst shaping

The shaping of the catalyst is the same as for catalyst A.

The composition of catalyst E is as follows: 50% by weight AI-IZM-2/0.85% by weight Pt/49.15% by weight Alumina.

Example 6: evaluation of the catalytic properties of catalysts B, C and D in accordance with the invention and A and E not in accordance with the invention, in isomerization of a paraffinic charge

The catalysts were tested in isomerization of a paraffinic charge composed of n-hexadecane. The tests were carried out in a micro-unit implementing a fixed bed reactor and working in downdraft without recycling. The analysis of hydrocarbon effluents is carried out online by gas chromatography. Once loaded into the unit, the catalyst undergoes a first stage of drying under nitrogen under the following conditions:

- nitrogen flow: 2 normal liters per hour and per gram of catalyst,

- total pressure: 0.1 MPa,

- temperature rise ramp from ambient to 150°C: 5°C/min,

- plateau at 150°C for 30 minutes.

After drying, the nitrogen is replaced by hydrogen and a reduction step under a flow of pure hydrogen is then carried out under the following conditions: - hydrogen flow: 5 normal liters per hour and per gram of catalyst,

- total pressure: 1.1 MPa,

- temperature rise ramp from 150 to 450°C: 5°C/min,

- plateau at 450°C for 1 hour. After the reduction step, the temperature has dropped to 230° C., and the catalyst is brought into contact with n-hexadecane under the following conditions:

- hourly space velocity of 2 grams of n-hexadecane per hour and per gram of catalyst,

- hydrogen partial pressure of 1.0 MPa, - total pressure of 1.1 MPa.

The conversion is modified by varying the temperature; and at each temperature level two analyzes of the effluent are carried out, which makes it possible to calculate the catalytic performances and to check the stability of the catalytic performances for said temperature level. Typically, the temperature is varied between 230 and 350°C in temperature steps of 5°C. Effluent analysis is performed entirely through an online GC (gas chromatography) system. The temperature necessary to reach 50% conversion acts as a descriptor of the activity of the catalyst, while the maximum yield obtained of hexadecane isomers acts as a descriptor of the isomerizing properties of the catalyst.

Table 2: catalytic performances of catalysts A, B, C, D and E in hydroconversion of n-hexadecane.

It can be seen that the non-compliant catalyst E, which implements an AI-IZM-2 (no presence of gallium) is the least selective catalyst of the series, with a maximum isomer yield of 81.3% whereas it is greater than 85% for the other catalysts A B C and D . The presence of gallium makes it possible to improve the isomerization selectivity of the catalysts. However, catalyst A, non-compliant, which implements a Ga-IZM-2 (no presence of aluminum) is the least active of the series. It has a temperature at 50% conversion high at 278°C, i.e. an activity deficit of 15°C compared to catalyst E, which does not conform, which has a temperature at 50% conversion at 263°C.

Compliant catalysts B, C and D, which use Ga-Al-IZM-2, exhibit both greater selectivity than non-compliant catalyst E (max. isomer yields between 85.6% and 89 .3% for compliant catalysts B C D compared to a yield of 81.3% for non-compliant catalyst E) and greater activity than non-compliant catalyst A (temperatures at 50% conversion between 259 and 271 °C per compared to a temperature at 50% conversion of 278° C. for non-compliant catalyst A). The conformal catalyst C is particularly interesting because it combines both a high isomerization selectivity and an activity comparable to catalyst E.

Claims

37

CLAIMS Catalyst comprising at least one metal from group VIII of the periodic table of elements, at least one matrix and at least one IZM-2 zeolite containing both aluminum and gallium, said IZM-2 zeolite having a molar ratio between the number of moles of silicon and the number of moles of aluminum and of gallium Si/(Al+Ga) between 35 and 175 and a molar ratio between the number of moles of gallium and the number of moles of aluminum and of gallium Ga/(Ga+Al) between 0.10 and 0.90. Catalyst according to Claim 1, in which the said Group VIII metal is chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum, alone or as a mixture. Catalyst according to Claim 2, in which the said group VIII metal is chosen from among the noble metals of group VIII, preferably chosen from palladium and platinum and preferably platinum. Catalyst according to Claim 3, in which the noble metal content of the said catalyst is between 0.01 and 5% by weight, preferably between 0.1 and 4% by weight and very preferably between 0.1 and 2% by weight. weight relative to the total mass of said catalyst. Catalyst according to one of Claims 1 to 4, in which the said matrix is chosen from the group formed by alumina, silica, silica-alumina, clays, titanium oxide, boron oxide, aluminates and zirconia, taken alone or as a mixture. Catalyst according to claim 5 wherein said matrix is alumina. Catalyst according to one of Claims 1 to 6, in which the molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) of the IZM-2 zeolite is between 40 and 150. Catalyst according to claim 7, in which the molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) of the IZM-2 zeolite is between 50 and 135 . 38 Catalyst according to one of claims 1 to 8 wherein the molar ratio between the number of moles of silicon and the number of moles of aluminum and gallium Si/(Al+Ga) of the IZM-2 zeolite is between 55 and 120. Catalyst according to one of Claims 1 to 9, in which the molar ratio between the number of moles of gallium and the number of moles of aluminum and gallium Ga/(Ga+Al) of the IZM-2 zeolite is between 0.20 and 0.80 and very preferably between 0.35 and 0.65. Process for isomerizing a paraffinic feedstock comprising paraffins having a number of carbon atoms between 9 and 25, said paraffinic feedstock being produced from renewable resources or by a process involving a step of recovery by Fischer-Tropsch, operating at a temperature between 200°C and 500°C, at a pressure between 0.45 MPa and 7 MPa, at an hourly space velocity between 0.1 and 10 h ^-1 , expressed in kilograms of charge introduced per kilogram of catalyst and per hour, in the presence of hydrogen and at a partial pressure of hydrogen of between 0.3 and 5.5 MPa, and implementing the catalyst according to one of Claims 1 to 10 Process according to Claim 11, in which the said paraffinic load comprises paraffins having a number of carbon atoms comprised between 10 and 22. Process according to one of Claims 11 or 12, in which the said paraffinic load is produced from res renewable sources chosen from vegetable oils, algae or algal oils, fish oils and fats of vegetable or animal origin, or mixtures of such fillers.