EP2499221A1

EP2499221A1 - Process for hydrotreatment and hydroisomerization of feedstocks resulting from a renewable source using a zeolite modified by a basic treatment

Info

Publication number: EP2499221A1
Application number: EP10787509A
Authority: EP
Inventors: Laurent Simon; Emmanuelle Guillon; Antoine Daudin
Original assignee: IFP Energies Nouvelles IFPEN
Current assignee: IFP Energies Nouvelles IFPEN
Priority date: 2009-11-10
Filing date: 2010-11-05
Publication date: 2012-09-19
Also published as: FR2952378A1; FR2952378B1; WO2011058241A1; US20110108460A1

Abstract

The present invention describes a process for treating feedstocks resulting from a renewable source using, in a hydroisomerization step, a catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the metals from group VIB and from group VIII of the Periodic Table and a support comprising at least one dealuminated zeolite Y having an initial overall atomic ratio of silicon to aluminium of between 2.5 and 20, an initial extra-lattice aluminium atom weight fraction of greater than 10%, relative to the total weight of the aluminium present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry of greater than 0.07 ml g^-1, and an initial lattice parameter a₀ of the unit cell between 24.38 Å and 24.30 Å, said zeolite being modified by a) a step of basic treatment consisting of mixing said dealuminated zeolite Y with a basic aqueous solution, and at least one step c) of heat treatment.

Description

METHOD FOR HYDROTREATING AND HYDROISOMERIZING RENEWABLE SOURCE-BASED LOADS USING MODIFIED ZEOLITHE BY BASIC TREATMENT

Technical area

In an international context marked by the rapid growth of fuel requirements, particularly diesel and kerosene bases in the European community, the search for new renewable energy sources that can be included in the traditional refining and fuel production scheme is a major issue.

As such, the integration into the refining process of new products of plant origin, resulting from the conversion of lignocellulosic biomass or from the production of vegetable oils or animal fats, has in recent years experienced a very lively renewed interest due to the rising cost of fossil fuels. Similarly, traditional biofuels (mainly ethanol or methyl esters of vegetable oils) have acquired a real status of supplementing petroleum fuels in fuel pools. In addition, the processes known to date using vegetable oils or animal fats are responsible for C0 ₂ emissions, known for these negative effects on the environment. A better use of these bio-resources, such as for example their integration in the fuel pool would therefore be a definite advantage.

The strong demand for diesel fuels and kerosene, coupled with the importance of environmental concerns, reinforces the interest of using renewable sources. These fillers include for example vegetable oils, animal fats, raw or having undergone prior treatment, as well as mixtures of such fillers. These fillers contain chemical structures of the triglyceride or ester or fatty acid type, the structure and the hydrocarbon chain length of the latter being compatible with the hydrocarbons present in gas oils and kerosene.

One possible route is the catalytic conversion of the renewable source feedstock into deoxygenated paraffinic fuel in the presence of hydrogen (hydrotreatment). Many metal catalysts or sulfides are known to be active for this type of reaction.

These hydrotreatment processes from renewable source are already well known and are described in many patents. For example, patents include US Pat. No. 4,992,605, US Pat. No. 5,705,722, EP 1, 681, 337 and EP 1, 741, 768.

The use of transition metal sulphide solids allows the production of paraffins from ester-type molecules in two reaction routes: - The hydrodeoxygenation leading to the formation of water by hydrogen consumption and the formation of carbon number (Cn) hydrocarbons equal to that of the initial fatty acid chains,

Decarboxylation / decarbonylation leading to the formation of carbon oxides (carbon monoxide and carbon dioxide: CO and CO2) and the formation of hydrocarbons having one less carbon (Cn-1) relative to the acid chains initial fat.

The liquid effluent from these hydrotreatment processes consists essentially of n-paraffins which can be incorporated into the diesel fuel and kerosene pool. In order to improve the cold properties of this hydrotreated liquid effluent, a hydroisomerization step is necessary to convert n-paraffins into branched paraffins having better properties when cold.

Patent application EP 1 741 768, for example, describes a process comprising a hydrotreatment followed by a hydroisomerization step in order to improve the cold properties of the linear paraffins obtained. The catalysts used in the hydroisomerization step are bifunctional catalysts consist of a metal active phase comprising a Group VIII metal chosen from palladium, platinum and nickel,

Q dispersed on a molecular sieve acidic support selected from SAPO-11, SAPO-41, ZSM-22, ferrierite or ZSM-23, said process operating at a temperature between 200 and 500 ° C, and at a pressure of between 2 and 15 MPa. Nevertheless, the use of this type of solid results in a loss of average distillate yield.

Zeolite modification by alkaline treatment is a process that has been studied in the open literature. This modification method by alkaline treatment makes it possible to create mesoporosity in certain type of zeolite, such as the microporous zeolite ZSM-5 in Ogura et al., Applied Catal. A: General, 219 (2001) 33, Groen et al., Colloids and Surfaces A: Physicochem. Eng. Aspects 241 (2004) 53, and Groen et al., Microporous and Mesoporous

0 Materials, 69 (2004) 29, FER in Groen et al., Microporous and Mesoporous Materials, 69 (2004) 29, MOR in Groen et al., Microporous and Mesoporous Materials, 69 (2004) 29 and Groen et al. J. Catal. 243 (2006) 212 or Zeolite BEA Groen et al., Microporous and Mesoporous Materials, 69 (2004) 29, Groen et al., J. Catal. 243 (2006) 212 and Groen et al., Microporous and Mesoporous Materials, 114 (2008) 93 and the catalysts obtained

Used for different catalytic reactions. These studies show that alkaline treatment allows to remove silicon atoms from the structure thus creating a mesoporosity. The creation of mesoporosity and the maintenance of the crystallinity and the acidic properties of the zeolite are identified in these publications as being related to the initial Si / Al global molar ratio of the zeolites, said optimum Si / Al global ratio to be between 20 and 20%. 50. In fact, apart from this range of global Si / Al ratio of between 20 and 50, and for example for an overall Si / Al ratio of less than 20, the structure of the zeolite is very stable because of the presence of a large number of aluminum atoms which prevent the extraction of silicon atoms and thus the creation of additional mesoporosity. Interest of the invention

The dealuminated Y zeolite contains mesopores, created by extracting aluminum atoms from the framework of the zeolite. The presence of mesopores makes it possible to improve the average distillate selectivity of the hydrocracking catalysts using such a zeolite by facilitating the diffusion of the primary products of the reaction (jet fuels and gas oils) and thus limiting overcracking to light products. However, the extraction of the aluminum atoms from the framework decreases the Bronsted acidity of said zeolite and therefore its catalytic activity. The gain in selectivity in middle distillates linked to the mesoporosity of the zeolite is therefore to the detriment of the catalytic activity. The research work carried out by the applicant on the modification of numerous crystallized microporous zeolites and solids and on the hydrogenating active phases led him to discover that, surprisingly, a catalyst for the hydroisomerization of paraffinic hydrocarbon feedstocks and in particular hydrotreating feedstock from a renewable source, comprising at least one hydro-dehydrogenating metal selected from the group consisting of Group VIB metals and Group VIII of the Periodic Table, taken alone or as a mixture and a carrier comprising at least one a dealuminated Y zeolite containing a specific weight fraction of extra-lattice aluminum atoms, said zeolite being modified by a) a basic treatment step consisting of the mixture of said dealuminated zeolite Y with a basic aqueous solution making it possible to remove silicon atoms of the structure and insert alum atoms extra-lattice inium in the framework of the zeolite, and at least one step c) heat treatment, allowed to obtain an activity, ie a higher conversion level, and a selectivity distillate means (kerosene and higher gas oils), the hydroisomerization step being carried out in a treatment method charges originating from a renewable source comprising, upstream of said hydroisomerization step, a hydrotreating step.

Without being bound by any theory, the basic treatment of the dealuminated zeolite and containing a specific weight fraction of initial extra-lattice aluminum atoms allows the creation of mesopores forming an interconnected network of mesopores to the surface of the crystals of zeolite, by desilication, that is to say by extraction of silicon atoms from the framework of the initial zeolite. The creation of mesoporosity accessible via the external surface of the zeolite crystals promoting the intercrystalline diffusion of the molecules, makes it possible for a catalyst employing said modified zeolite according to the invention, used in a process for producing middle distillates, to obtain a selectivity in distillate means higher. Furthermore, the basic treatment also allows realumination, ie the reintroduction of at least a portion of extra-lattice aluminum atoms present in the initial zeolite in the framework of the modified zeolite, this realumination allowing an increase of the Bransted acidity of the modified zeolite, resulting in a catalyst implementing said modified zeolite according to the invention, by improved catalytic properties, ie a better conversion.

An object of the invention is therefore to provide a process for the treatment of charges from a renewable source implementing, in a hydroisomerisation step, downstream of a hydrotreatment step, a hydroisomerization catalyst comprising a support for modified zeolite base making it possible to obtain high yields of gasolines and kerosene bases.

Another object of the invention is to provide a process for the treatment of charges from a renewable source implementing, in a hydroisomerisation step, downstream of a hydrotreating step, a catalyst comprising as a support a modified zeolite allowing minimize the production of light fraction 150 ° C

OBJECT OF THE INVENTION More specifically, the invention relates to a process for treating charges from a renewable source comprising the following steps:

a) hydrotreatment in the presence of a fixed bed catalyst, at a temperature between 200 and 450 ° C, at a pressure of between 1 MPa and 10 MPa, at a space velocity of between 0.1 h ^"1 and 10 h ^"1 and in the presence of a total amount of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1000 Nm ³ of hydrogen / m ³ of feed, b) separation from the effluent from step a) of hydrogen, gases and at least one hydrocarbon base,

c) hydroisomerization of at least a portion of said hydrocarbon base resulting from step b) in the presence of a fixed bed hydroisomerization catalyst, said catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the Group VIB and Group VIII metals of the Periodic Table, taken singly or in admixture and a carrier comprising at least one dealuminated Y zeolite having an initial total silicon to aluminum atomic ratio of between 2.5 and 20, a weight fraction of an extra initial network aluminum atom greater than 10%, relative to the total mass of aluminum present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry greater than 0.07 ml. g ^"1 , and an initial crystal parameter at ₀ of the elemental mesh between 24.38 A and 24.30 A, said zeolite being modified by a) a basic treatment step consisting of mixing said dealuminated zeolite Y with a basic aqueous solution, and at least one step c) of heat treatment, said hydroisomerization step being carried out at a temperature of between 150 and 500 ° C, at a pressure of between 1 MPa and 10 MPa, at an hourly space velocity of between 0.1 and 10 h ^-1 and in the presence of a total amount of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1000 Nm ³ / m ³ of feed,

d) separation, from the effluent from step c) of hydrogen, gases and at least one gas oil base and a kerosene base.

Detailed description of the invention

The present invention is particularly dedicated to the preparation of gas oil and kerosene fuel bases corresponding to the new environmental standards, from charges from renewable sources.

The feedstocks derived from renewable sources used in the present invention are advantageously chosen from oils and fats of vegetable or animal origin, or mixtures of such fillers, containing triglycerides and / or free fatty acids and / or esters. Vegetable oils can advantageously be crude or refined, wholly or in part, and derived from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha, this list not being limiting. Algae or fish oils are also relevant. Animal fats are advantageously chosen from lard or fats composed of residues from the food industry or from the catering industries. These fillers essentially contain triglyceride-type chemical structures which are also known to those skilled in the art as tri-ester of fatty acids as well as free fatty acids. A fatty acid ester tri is thus composed of three chains of fatty acids. These fatty acid chains in the form of triester ester or in the form of free fatty acid have a number of unsaturations per chain, also called number of carbon-carbon double bonds per chain, generally between 0 and 3 but which can be higher especially for oils derived from algae which generally have a number of unsaturations in chains of 5 to 6.

The molecules present in the feeds from renewable sources used in the present invention therefore have a number of unsaturations, expressed per molecule of triglyceride, advantageously between 0 and 18. In these feeds, the level of unsaturation, expressed in number unsaturated hydrocarbon fatty chain, is advantageously between 0 and 6.

Charges from renewable sources generally also include 5 different impurities and especially heteroatoms such as nitrogen. Nitrogen levels in vegetable oils are generally between about 1 ppm and about 100 ppm by weight, depending on their nature. They can reach up to 1% weight on particular loads.

Advantageously, the feedstock may undergo prior to step a) of the process according to the invention a pre-treatment or pre-refining step so as to eliminate, by an appropriate treatment, contaminants such as metals, such as alkaline compounds for example on ion exchange resins, alkaline earths and phosphorus. Suitable treatments may for example be heat treatments and / or

: 5 chemicals well known to those skilled in the art.

According to step a) of the process according to the invention, the charge, possibly pretreated, is brought into contact with a catalyst in a fixed bed at a temperature of between 200 and 450 ° C., preferably between 220 and 350 ° C. preferably between 220 and 320 ° C,

I0 and even more preferably between 220 and 310 ° C. The pressure is between 1 MPa and 10 MPa, preferably between 1 MPa and 6 MPa and even more preferably between 1 MPa and 4 MPa. The hourly space velocity is between 0.1 hr-1 and 10 hr-1. The filler is contacted with the catalyst in the presence of hydrogen. The total amount of hydrogen mixed with the feed is such that the hydrogen / feed ratio is included

Between 70 and 1000 Nm3 of hydrogen / m 3 of filler and preferably between 150 and 750 Nm3 of hydrogen / m 3 of filler. In step a) of the process according to the invention, the fixed-bed catalyst is advantageously a hydrotreatment catalyst comprising a hydro-dehydrogenating function comprising at least one metal of group VIII and / or group VI B, taken alone or in a mixture and a support selected from the group consisting of alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals. This support may also advantageously contain other compounds and for example oxides selected from the group formed by boron oxide, zirconia, titanium oxide, phosphoric anhydride. The preferred support is an alumina support and very preferably alumina η, δ or γ.

Said catalyst is preferably a catalyst comprising metals of the VIII preferably group selected from nickel and cobalt, used alone or in admixture, preferably in ^* combination with at least one group VIB metal, preferably selected from molybdenum and tungsten , taken alone or in a mixture.

The content of metal oxides of groups VIII and preferably of nickel oxide is advantageously between 0.5 and 10% by weight of nickel oxide (NiO) and preferably between 1 and 5% by weight of oxide of nickel. and the content of metal oxides of groups VIB and preferably of molybdenum trioxide is advantageously between 1 and 30% by weight of molybdenum oxide (MoO ₃ ), preferably from 5 to 25% by weight, the percentages being expressed in% by weight relative to the total mass of the catalyst.

The total content of metal oxides of groups VIB and VIII in the catalyst used in step a) is advantageously between 5 and 40% by weight and preferably between 6 and 30% by weight relative to the total mass. catalyst.

The weight ratio expressed as metal oxide between metal (or metals) of group VIB on metal (or metals) of group VIII is advantageously between 20 and 1 and preferably between 10 and 2.

Said catalyst used in step a) of the process according to the invention must advantageously be characterized by a high hydrogenating power so as to orient as much as possible the selectivity of the reaction towards a hydrogenation preserving the number of carbon atoms of the fatty chains. ie the hydrodeoxygenation route, this in order to maximize the yield of hydrocarbons entering the distillation field of kerosenes and / or gas oils. This is why, preferably, one operates at a relatively low temperature. Maximizing the hydrogenating function also makes it possible to limit the polymerization and / or condensation reactions leading to the formation of coke which would degrade the stability of the catalytic performances. Preferably, a Ni or NiMo type catalyst is used.

Said catalyst used in step a) of hydrotreating of the process according to the invention may also advantageously contain a doping element chosen from phosphorus and boron, taken alone or as a mixture. Said doping element may be introduced into the matrix or preferably deposited on the support. It is also possible to deposit silicon on the support, alone or with phosphorus and / or boron and / or fluorine.

The oxide weight content of said doping element is advantageously less than 20% and preferably less than 10% and is advantageously at least 0.001%.

The metals of the catalysts used in step a) of hydrotreatment of the process according to the invention are sulphide metals or metal phases and preferably sulphurized metals. It would not be departing from the scope of the present invention by using in step a) of the process according to the invention, simultaneously or successively, a single catalyst or several different catalysts. This step can be carried out industrially in one or more reactors with one or more catalytic beds and preferably downflow of liquid.

According to step b) of the process according to the invention, the hydrotreated effluent from step a) is subjected at least in part, and preferably entirely, to one or more separations. The purpose of this step is to separate the gases from the liquid, and in particular to recover the hydrogen-rich gases that may also contain gases such as CO and CO ₂ and at least one liquid hydrocarbon base with a sulfur content of less than 10 ppm by weight. . The separation is carried out according to all methods of separation known to those skilled in the art. The separation step may advantageously be carried out by any method known to those skilled in the art such as, for example, the combination of one or more high and / or low pressure separators, and / or distillation and / or distillation stages. high and / or low pressure stripping. The water that may be formed during step a) of hydrotreatment of the process according to the invention may also be advantageously separated at least in part from the liquid hydrocarbon base. The separation step b) may therefore advantageously be followed by an optional step of removing at least a portion of the water and preferably all of the water.

The purpose of the optional water removal step is to remove at least a portion of the water produced during the hydrotreatment reactions. The elimination of water is the elimination of the water produced by the hydrodeoxygenation (HDO) reactions. The more or less complete elimination of water may be a function of the water tolerance of the hydroisomerization catalyst used in the subsequent step c) of the process according to the invention. The elimination of water can be carried out by all the methods and techniques known to those skilled in the art, for example by drying, passing on a desiccant, flash, decantation .... In accordance with step c) of the process according to the invention, at least part and preferably all of the liquid hydrocarbon base obtained at the end of step b) of the process according to the invention is hydroisomerized in the presence of a fixed bed hydroisomerization catalyst said catalyst comprising at least one hydrodehydrogenating metal selected from the group consisting of Group VIB metals and Group VIII of the Periodic Table, taken singly or in admixture and a carrier comprising at least one dealuminated Y zeolite having an atomic ratio initial total of silicon on aluminum between 2.5 and 20, a weight fraction of extra-initial network aluminum atom greater than 10%, relative to the total mass of aluminum present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry greater than 0.07 ml.g ^{: 1} , and an initial crystal parameter at ₀ of the unit cell between 24.38 A and 24.30A, said zeolite being modified according to a particular method.

The hydrogen phase

According to the invention, the catalyst used in the hydroisomerization step c) of the process according to the invention comprises at least one hydro-dehydrogenating metal chosen from the group formed by the metals of group VIII and the metals of the group VIB, taken alone or as a mixture.

Preferably, the group VIII elements are chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium or platinum, taken alone or as a mixture. In the case where the elements of group VIII are chosen from the noble metals of group VIII, the elements of group VIII are advantageously chosen from platinum and palladium, taken alone or as a mixture. In the case where the elements of group VIII are selected from non-noble metals of group VIII, the elements of group VIII are advantageously chosen from iron, cobalt and nickel, taken alone or as a mixture.

Preferably, the group VIB elements of the catalyst according to the present invention are selected from tungsten and molybdenum, alone or as a mixture.

In the case where the hydrogenating function comprises a group VIII element and a group VIB element, the following metal combinations are preferred: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, and very preferably: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten. It is also possible to use combinations of three metals such as for example nickel-cobalt-molybdenum.

When a combination of Group VIB and Group VIII metals is used, then the catalyst is preferably used in a sulfurous form. In the case where the catalyst comprises at least one Group VIB metal in combination with at least one Group VIII non-noble metal, the Group VIB metal content is advantageously comprised, in oxide equivalent, of between 5 and 40% by weight per relative to the total mass of said catalyst, preferably between 10 and 35% by weight and very preferably between 15 and 30% by weight and the non-noble metal content of group VIII is advantageously comprised, in oxide equivalent, between 0 , 5 and 10% by weight relative to the total mass of said catalyst, preferably between 1 and 8% by weight and very preferably between 1, 5 and 6% by weight.

In the case where the catalyst comprises at least one Group VIB metal in combination with at least one Group VIII non-noble metal, said catalyst may also advantageously comprise at least one doping element selected from the group consisting of silicon, boron and phosphorus, taken alone or as a mixture, the content of doping element being preferably between 0 and 20% by weight of oxide of the doping element, preferably between 0.1 and 15% by weight, very preferably preferred between 0.1 and 10% by weight and even more preferably between 0.5 and 6% by weight relative to the total mass of the catalyst. When the hydro-dehydrogenating element is a noble metal of group VIII, the catalyst preferably contains a noble metal content of between 0.01 and 10% by weight, even more preferably from 0.02 to 5% by weight relative to to the total mass of said catalyst. The noble metal is preferably used in its reduced and non-sulphurized form.

It is also advantageously possible to employ a reduced, non-sulfurized nickel-based catalyst. In this case the metal content in its oxide form is advantageously between 0.5 and 25% by weight relative to the finished catalyst. Preferably, the catalyst also contains, in addition to the reduced nickel, a group IB metal and preferably copper, or a group IVB metal and preferably tin in proportions such that the mass ratio of the group metal IB or IVB and nickel on the catalyst is advantageously between 0.03 and 1.

Said hydroisomerization catalyst used in stage c) of the process according to the invention comprises a support comprising at least one modified zeolite and advantageously a porous oxide matrix of oxide type, said support comprising and preferably consisting of, preferably:

0.1 to 99.8% by weight, preferably 0.1 to 80% by weight, even more preferably 0.1 to 70% by weight, and very preferably 0.1 to 50% by weight; by weight of zeolite modified according to the invention with respect to the total mass of the catalyst,

From 0.2 to 99.9% by weight, preferably from 20 to 99.9%, preferably from 30 to 99.9% by weight, and very preferably from 50 to 99.9% by weight relative to to the total mass of the catalyst, at least one oxide-type porous mineral matrix. Zeolite according to the invention

According to the invention, the zeolite initially used which is suitable for carrying out the support of the catalyst used in the hydroisomerization step c) of the process according to the invention is the dealuminated Y zeolite (USY) of structural type FAU . According to the invention, the dealuminated initial zeolite Y, which is suitable for carrying out the support of the catalyst used in the hydroisomerization step c) of the process according to the invention, has, before being modified, an initial overall atomic ratio. of silicon on aluminum of between 2.5 and 20.0, preferably between 2.6 and 12.0, and preferably between 2.7 and 10.0, a weight fraction of extra high initial network aluminum atom at 10%, preferably greater than 20% and preferably greater than 30% by weight relative to the total weight of the aluminum present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry greater than 0.07 ml · g ^-1 , preferably greater than 0.10 ml · g ^-1 , and more preferably greater than 0.13 ml g ^{" 1} and an initial crystal parameter at ₀ of the elemental mesh of between 24.38 Å and 24.30 Å, preferably the dealuminated initial zeolite Y which is suitable for carrying out the support of the catalyst used in step c) hydroisomerization of the process according to the invention, before being modified, an initial microporous volume measured by nitrogen porosimetry greater than 0.20 ml.g ^-1 , and preferably greater than 0.25 ml.g. ^"1 .

According to the invention, said dealuminated initial zeolite Y having an initial total silicon / Si / Al atomic atomic ratio of between 2.5 and 20.0, preferably between 2.6 and 12.0, and preferably between 2, 7 and 10.0, said overall Si / Al atomic ratio being measured by X-ray fluorescence (FX) and exhibiting an aluminum network NMR fraction by weight of greater than 10%, preferably greater than 20% and preferably greater than 30% by weight relative to the total weight of the aluminum present in the zeolite is obtained by dealumination of a zeolite Y of FAU structural type by all the known de-lulmination methods of the skilled person.

Preparation of the initial zeolite Y dealuminated.

The FAU structural zeolite Y, which is advantageously in the NaY form after synthesis, may advantageously undergo one or more ionic exchanges before undergoing the dealumination step.

The dealumination treatment of the FAU structural zeolite Y generally having an overall Si / Al atomic ratio after synthesis of between 2.3 and 2.8 can advantageously be carried out by all the methods known to those skilled in the art. Preferably, the dealumination is carried out by a heat treatment in the presence of water vapor (or steaming according to the English terminology) and / or by one or more

) Acid attacks advantageously carried out by treatment with an aqueous solution of mineral or organic acid.

Preferably, the dealumination is carried out by a heat treatment followed by one or more acid attacks or only by one or more acid attacks.

Preferably, the thermal treatment in the presence of water vapor to which zeolite Y is subjected is carried out at a temperature of between 200 and 900 ° C, preferably between 300 and 900 ° C, even more preferably between 400 and 750 ° C. The duration of the said Heat treatment is advantageously greater than or equal to 0.5h, preferably between 0.5h and 24h, and very preferably between 1h and 12h. The volume percentage of water vapor during the heat treatment is advantageously between 5 and 100%, preferably between 20 and 100%, so

5 between 40% and 100%. The volume fraction other than the water vapor that may be present is formed of air. The gas flow rate formed by water vapor and optionally air is advantageously between 0.2 L / h / g and 10 L / h / g of zeolite Y.

The heat treatment makes it possible to extract the aluminum atoms from the framework of zeolite Y while maintaining the overall atomic ratio Si / Al of the treated zeolite

0 unchanged.

The heat treatment in the presence of water vapor is advantageously repeated as many times as is necessary to obtain the dealuminized initial zeolite Y suitable for the implementation of the catalyst support used in step c) hydroisomerization of the process according to the invention having the desired characteristics and in particular a weight fraction S extra-network aluminum atom representing more than 10% by weight relative to the total weight of aluminum present in said zeolite. The number of heat treatment is advantageously less than 4 and preferably, a single heat treatment is performed at the end of which the weight fraction of extra-initial network aluminum atom is measured by NMR of aluminum.

0

In order to carry out a dealumination of said zeolite Y and to adjust the overall Si / Al atomic ratio of the dealuminated zeolite Y to a value of between 2.5 and 20 according to the invention, it is necessary to choose and control the conditions operations of each acid etching step. In particular, the temperature at which treatment with the solution

The nature and concentration of the acid used, the ratio of the amount of acid solution to the weight of zeolite treated, the duration of the acid attack treatment and the number of of treatment performed are significant parameters for the implementation of each acid attack step.

The acid chosen for the implementation of said acid attack step is advantageously

S0 is a mineral acid or an organic acid, preferably the acid is a mineral acid selected from nitric acid HN0 ₃ , hydrochloric acid HCl and sulfuric acid H ₂ SO ₄ . Most preferably, the acid is nitric acid. When an organic acid is used for etching, acetic acid CH ₃ CO ₂ H is preferred.

Preferably, the acid etching treatment of zeolite Y with an aqueous solution of a mineral acid or an organic acid is carried out at a temperature of between 30 ° C and 120 ° C, preferably between 50 ° C. and 120 ° C, and preferably between 60 and 100 ° C. The 00738

14

concentration of the acid in the aqueous solution is advantageously between 0.05 and 20 mol.L ^-1 , preferably between 0.1 and 10 mol.l ^-1 , and more preferably between 0.5 and 5 mol .L ^"1. the ratio between the volume V of acid solution in ml and the weight of zeolite Y treated P in grams is advantageously between 1 and 50 and preferably between 2 and 20. the duration of the acid attack is advantageously greater than 1h, preferably between 2h and 10h, and preferably between 2h and 8h.The number of successive acid etching treatment of the zeolite Y with an acidic aqueous solution is advantageously less than 4. In the case where several successive acid attack treatments are carried out, aqueous solutions of mineral or organic acid of different acid concentrations can be used.

In order to adjust the overall Si / Al atomic ratio of the dealuminated Y zeolite to a value between 2.5 and 20, said ratio is measured by X-ray fluorescence after each acid etching treatment carried out. After carrying out the acid etching treatment (s), the zeolite is then advantageously washed with distilled water and is then dried at a temperature of between 80 and 140 ° C. for a period of between 10 and 48 hours.

Acid etching treatment both extracts the aluminum atoms from the framework and extracts the aluminum atoms from the pores of the zeolitic solid. Thus, the overall atomic ratio Si / Al of the dealuminated Y zeolite obtained increases to a value of between 2.5 and 20, said zeolite being suitable for carrying out the catalyst support used in the process according to the invention. Similarly, said dealuminated initial zeolite Y obtained and suitable for carrying out the support of the catalyst used in the hydroisomerization step c) of the process according to the invention has, after dealumination, an initial mesoporous volume measured by porosimetry at nitrogen greater than 0.07 ml.g ^-1 , preferably greater than 0.10 ml g ^-1 , and more preferably greater than 0.13 ml g ^-1 , the creation of mesoporosity resulting from the extraction of aluminum atoms out of the pores of the zeolithitic solid and an initial crystal parameter at ₀ of the elemental mesh between 24.38 A and 24.30 A.

Said dealuminated initial zeolite Y also advantageously has an initial microporous volume measured by nitrogen porosimetry greater than 0.20 ml · g ^-1 , and preferably greater than 0.25 ml · g ^-1 . The microporous and mesoporous volumes of the dealuminated zeolite Y are measured by nitrogen adsorption / desorption and the zeolite mesh parameter is measured by X-ray diffraction (XRD). Process for modifying the initial dealuminated zeolite Y according to the invention

According to the invention, the dealuminated initial zeolite Y which is suitable for carrying out the catalyst support used in the process according to the invention is modified by a specific modification process comprising a) a basic treatment step consisting in mixing said dealuminated Y zeolite with a basic aqueous solution, said basic aqueous solution being a solution of basic compounds chosen from alkaline bases and non-alkaline strong bases, said step a) being carried out at a temperature of between 40 and 100 ° C. and for a period of between 5 minutes and 5 hours and at least one c) heat treatment step performed at a temperature between 200 and 700 ° C.

Stage a ') of basic treatment makes it possible to remove silicon atoms from the structure and to insert extra-lattice aluminum atoms into the framework.

According to the invention, the process for modifying said dealuminated initial zeolite Y comprises a basic treatment step a ') consisting of mixing said dealuminated zeolite USY with a basic aqueous solution, said basic aqueous solution being a solution of selected basic compounds among the alkaline bases and the non-alkaline strong bases, said step a) being carried out at a temperature between 40 and 100 ° C and for a period of between 5 minutes and 5 hours.

The basic compounds chosen from alkaline bases are preferably chosen from alkali carbonates and alkali hydroxides, alkaline cations from alkali carbonates and alkali hydroxides advantageously belonging to groups IA or HA of the periodic table and the non-alkaline strong bases are from preferably chosen from quaternary ammoniums, taken alone or as a mixture and, preferably, the non-alkaline strong base is tetramethylammonium hydroxide.

Said alkaline cations of the alkali carbonates and alkali hydroxides advantageously belonging to the groups IA or HA of the periodic table are preferably chosen from Na ⁺ , Li ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Ba ²⁺ and Ca ²⁺ cations. and very preferably, said cation is the Na ⁺ or K ⁺ cation.

Preferably, the aqueous solution is a solution of sodium carbonate or sodium hydroxide and more preferably the aqueous solution is a solution of sodium hydroxide. Said basic aqueous solution of concentration of between 0.001 mol / L and 12 mol / L, preferably of concentration between 0.005 mol / L and 11 mol / L and even more preferably of concentration between 0.01 mol / L and 9 mol / L mol / L.

According to the invention, step a ') of basic treatment of the process for modifying said dealuminated initial USY zeolite is carried out under conditions of temperatures between 40 and 100 ° C. (reflux) and preferably between 40 and 90 ° C. ° C and for a period of between 5 min and 5h, preferably between 15 min and 4 h and even more preferably between 15 min and 3 h.

Once the basic treatment of said zeolite is complete, the solution is rapidly cooled to room temperature and then said zeolite is separated from the liquid by all the techniques known to those skilled in the art. The separation can be carried out by filtration or by centrifugation, and preferably by centrifugation. The modified modified USY zeolite is then washed with distilled water at a temperature of between 20 and 100.degree.

Preferably at a temperature between 40 and 80 ° C and very preferably at 50 ° C and dried at a temperature between 80 and 150 ° C and preferably between 100 and 130 ° C and very preferably at 120 ° C vs.

In the case where the basic treatment step a ') consists of mixing said dealuminated initial zeolite Y with a basic aqueous solution of compounds selected from alkaline bases, the zeolite contained in the catalyst support used in the process according to the invention contains, at the end of step a) of the modification process, a partial or total fraction of alkaline ions in the cationic position.

In the case where the basic treatment step a) consists in mixing said dealuminated initial zeolite Y with a basic aqueous solution of compounds selected from non-alkaline bases, the zeolite contained in the catalyst support used in the method according to the invention contains, at the end of step a ') of the modification process, a partial or total fraction of quaternary ammonium ions in the cationic position.

S0

During step a ') of basic treatment of the process of modification of the dealuminated initial zeolite Y according to the invention, a part of the silicon atoms contained in the framework of said zeolite are extracted, the phenomenon is called desilication, creating in the structure and the formation of a mesoporosity and / or allowing the reinsertion of at least part of the fraction of extra-lattice aluminum atoms present in said dealuminated initial zeolite Y, in place of the atoms of silicon extracted by desilication and thus allowing the formation of new Bronsted acid sites. This second phenomenon is called re-alumination.

In the case where the basic treatment step a ') consists in mixing said USY dealuminated initial zeolite with a basic aqueous solution of basic compounds chosen from alkaline bases and preferably chosen from alkaline carbonates and alkali hydroxides and from very preferably with a solution of sodium hydroxide (NaOH), the process for modifying said dealuminized initial USY zeolite advantageously comprises a step b ') of at least one partial or total exchange of said alkaline cations belonging to groups IA and IIA of the periodic table introduced during step a ') and present in the cationic position, by NH ₄ ⁺ cations and preferably Na ⁺ cations by NH ₄ ⁺ cations.

Partial or total exchange of the alkaline cations by NH ⁺ cations is understood to mean the exchange of 80 to 100%, preferably 85 to 99.5% and more preferably 88 to 99%, of said alkaline cations by NH ₄ ⁺ cations. The amount of alkaline cations remaining and preferably, the amount of Na ⁺ cations remaining in the modified zeolite, relative to the amount of NH ₄ ⁺ cations initially present in the zeolite, at the end of step b ') is advantageously between 0 and 20%, preferably between 0.5 and 15%, preferably between 1 and 12%.

Preferably, for this step, several ion exchange (s) are carried out with a solution containing at least one ammonium salt chosen from the salts of chlorate, sulfate, nitrate, phosphate, or ammonium acetate, of in order to eliminate at least partly the alkaline cations and preferably the Na ⁺ cations present in the zeolite. Preferably, the ammonium salt is ammonium nitrate NH ₄ NO ₃ .

Thus, the content of alkaline cations remaining and preferably Na ⁺ cations in the zeolite modified at the end of step b ') is preferably such that the molar ratio alkali metal cation / aluminum and preferably the molar ratio Na / AI is between 0.2: 1 and 0: 1, preferably between 0.15: 1 and 0.005: 1, and more preferably between 0.12: 1 and 0.01: 1.

The desired Na / Al ratio is obtained by adjusting the NH ⁺ concentration of the cation exchange solution, the cation exchange temperature, and the cation exchange number. The concentration of the NH ⁺ solution in the solution advantageously varies between 0.01 and 12 mol / l, and preferably between 1 and 10 mol / l. The temperature of the stage the exchange temperature is advantageously between 20 and 100 ° C., preferably between 60 and 95 ° C., preferably between 60 and 90 ° C., more preferably between 60 and 85 ° C. and even more preferably between 60 and 85 ° C. 80 ° C. The cation exchange number advantageously varies between 1 and 10 and preferably between 1 and 4.

In the case where the basic treatment stage a ') consists in mixing said USY dealuminated initial zeolite with an aqueous solution of basic compounds chosen from non-alkaline strong bases, preferably chosen from quaternary ammoniums, taken alone or as a mixture and preferably, the non-alkaline strong base being tetramethylammonium hydroxide, the modified zeolite from step a ') contains a partial or total fraction of quaternary ammonium ions in the cationic position.

In this case, the process for modifying said dealuminized initial USY zeolite advantageously does not comprise step b ') of at least one partial or total intermediate exchange, the modified zeolite resulting from step a) undergoes the step directly. c ') heat treatment.

According to the invention, the process for modifying the dealuminated initial zeolite Y then comprises at least one step c ') of heat treatment.

In the case where the basic treatment step a ') consists in mixing said USY dealuminated initial zeolite with a basic aqueous solution of compounds chosen from alkaline bases and preferably chosen from alkaline carbonates and alkaline hydroxides and very preferred with a solution of sodium hydroxide (NaOH), step c ') of heat treatment allows both the drying and the conversion of NH ⁺ cations exchanged during step b'), into protons.

In the case where the basic treatment step a ') consists in mixing said USY dealuminated initial zeolite with a basic aqueous solution of compounds chosen from non-alkaline strong bases and preferably chosen from quaternary ammoniums, taken alone or as a mixture and, preferably, the non-alkaline strong base being tetramethylammonium hydroxide, the thermal treatment step c ') allows both the drying and the decomposition of the quaternary ammonium cations in the counter-ion position and the formation of protons.

In all cases, at the end of said heat treatment step c '), the protons of the zeolite are partially or completely regenerated. Stage c ') of heat treatment according to the invention is carried out at a temperature between 200 and 700 ° C, more preferably between 300 and 500 ° C. Said processing step Thermally is advantageously carried out under air, under oxygen, under hydrogen, under nitrogen or under argon or under a mixture of nitrogen and argon. The duration of said treatment is advantageously between 1 and 5 hours.

At the end of the modification process according to the invention, the final modified zeolite used in the catalyst support used in the process according to the invention advantageously has a final mesoporous volume, measured by high nitrogen porosimetry. at least 10% relative to the initial mesoporous volume and preferably greater than at least 20% relative to the initial mesoporous volume of the dealuminated initial zeolite

0 USY, a final microporous volume measured by nitrogen porosimetry which must not decrease by more than 40%, preferably by more than 30% and preferably by more than 20% relative to the initial microporous volume of said zeolite initial dealuminated USY, a higher Bronsted acidity of more than 10% and preferably more than 20% with respect to the Bronsted acidity of the initial dealuminated zeolite Y and a crystalline parameter

S final a ₀ of the elementary cell superior to the initial crystalline parameter at ₀ of the mesh of the initial dealuminated zeolite Y.

At the end of the process for modifying the dealuminated zeolite Y according to the invention, the significant increase in the mesoporous volume of the resulting modified zeolite and the

Maintaining a significant microporous volume relative to the initial dealuminated Y zeolite translate the creation of additional mesoporosity by desilication.

Moreover, the increase in the Bronsted acidity of the final modified zeolite with respect to the initial dealuminated Y zeolite demonstrates the reintroduction of extra-lattice aluminum atoms in the framework of the zeolite, ie the phenomenon of

5 real estate.

The amorphous or poorly crystallized porous mineral matrix of oxide type

The catalyst support used in the hydroisomerization step c) of the process according to the invention advantageously contains a porous mineral matrix, preferably amorphous, which advantageously consists of at least one refractory oxide. said

The matrix is advantageously chosen from the group formed by alumina, silica, clays, titanium oxide, boron oxide and zirconia, taken alone or as a mixture. The matrix may consist of a mixture of at least two of the oxides mentioned above, and preferably silica-alumina. It is also possible to choose aluminates. It is preferred to use matrices containing alumina, in all these forms known to those skilled in the art, for example gamma-alumina. It is also advantageous to use mixtures of alumina and silica, mixtures of alumina and silica-alumina.

Characterization techniques

The overall Si / Al atomic ratio of the initial and final dealuminated Y zeolite, that is to die after modification is measured by X-ray fluorescence. X-ray fluorescence is a global elemental analysis technique that allows the analysis of all elements of the periodic system from boron. It is possible to dose from a few ppm up to 100%. In this invention, this technique is used to measure the silicon and aluminum zeolites (in percent by weight) and thus allows to calculate the atomic ratio Si / Al.

The weight fraction of the tetracoordinated and hexacoordinated aluminum atoms present in the modified USY zeolite is determined by nuclear magnetic resonance of the ²⁷ Al solid. Aluminum NMR is indeed known to be used for identifying and quantifying the various coordination states of this nucleus ("Physico-chemical analysis of industrial catalysts", J. Lynch, Technip Publishing (2001) Chapter 13, pages 290 and 291). The NMR spectrum of the aluminum of the original USY zeolite and that of the modified USY zeolite according to the invention has two signals, one of which is characteristic of the resonance of the tetracoordinated aluminum atoms (i.e. aluminum included in the crystal lattice of the zeolite) and the other being characteristic of the resonance of hexacoordinated aluminum atoms (ie aluminum atoms outside the lattice or extra-lattice aluminum atoms) . The tetracoordinated aluminum atoms A \ _w resonate at a chemical shift of between +40 ppm and +75 ppm and the hexacoordinated or extra-lattice aluminum Alvi atoms resonate at a chemical shift between -15 ppm and +15 ppm. The weight fraction of the two aluminum species Aliv and AI _V | is quantified by integrating the signals corresponding to each of these species.

More specifically, the USY zeolite modified according to the present invention in the catalyst support according to the invention was analyzed by MAS-NMR of the solid on a ²⁷ AI Briicker type of spectrometer Avance 400 MHz using a probe 4 mm optimized for F ²⁷ AI. The rotation speed of the sample is close to 14 kHz. The aluminum atom is a quadrupole nucleus with a spin equal to 5/2. Under so-called selective analysis conditions, namely a low radiofrequency field equal to 30 kHz, a low pulse angle equal to π / 2 and in the presence of a water-saturated sample, the magic angle spinning NMR (MAS) technique, referred to as MAS-NMR, is a quantitative technique. The decomposition of each NMR-MAS spectrum gives direct access to the quantity of the different aluminum species, namely Aliv tetracoordinated aluminum atoms and hexacoordinated aluminum atoms or Alvi extra-network aluminum atoms. Each spectrum is wedged in chemical shift with respect to a 1 M solution of aluminum nitrate for which the aluminum signal is at zero ppm. The signals characterizing the Aliv tetracoordinated aluminum atoms are integrated between +40 ppm and +75 ppm which corresponds to the area 1 and the signals characterizing the Alvi hexacoordinated aluminum atoms are integrated between -15 ppm and +15 ppm. which corresponds to area 2. The weight fraction of the hexacoordinated aluminum atoms Alvi is equal to the ratio area 2 / (area 1 + area 2).

The crystalline parameter of mesh aO zeolites Y dealuminated initial and final, that is to say after modification is measured by X-ray diffraction (XRD). For the FAU type Y zeolite, the mesh parameter a0 is calculated from the peak positions corresponding to the Miller indices 533, 642 and 555 ("Theory and technique of radiocrystallography", A. Guinier, Dunod edition, 1964). . Since the length of the bond AI-O is greater than that of the bond Si-O, the larger the number of aluminum in the tetrahedral position in the framework of al zeolite, the greater the parameter aO is large. For crystals consisting of cubic meshes such as F-type Y zeolites, a linear relationship exists between the mesh parameter a0 and the Si / Al ratio. ("Hydrocracking Science and Technology, Scherzer J., A. J. Gruia, Marcel Dekker Inc., 1996)

The microporous and mesoporous volumes of the initial dealuminated zeolite Y and fianle are measured by adsorption / desorption of nitrogen. The analysis of the nitrogen adsorption isotherm curves of the microporous and mesoporous solids allows the calculation of the porous volumes by the so-called volumetric technique technique. Different types of models are usable. The porous distribution measured by nitrogen adsorption was determined by the Barrett-Joyner-Halenda model (BJH). The nitrogen adsorption-desorption isotherm according to the BJH model is described in the periodical "The Journal of American Society", 73, 373, (1951) written by EPBarrett, LGJoyner and PPHalenda. In the following description of the invention, the term nitrogen adsorption volume, the volume measured for P / P0 = 0.95. The microporous volume is obtained by the "t-plot" method or by measuring the adsorbed volume at P / PO = 0.35 (P = adsorption pressure, PO = saturation vapor pressure of the adsorbate at the test temperature). The mesoporous volume is obtained by subtracting the microporous volume from the total pore volume.

The acidity of Lewis and Bronsted zeolites is measured by Pyridine adsorption followed by infra-red spectroscopy (FTIR). The integration of the characteristic bands of the coordinated pyridine at 1455 cm ^-1 and the protonated pyridine at 1545 cm ^-1 makes it possible to compare the relative acidity of the Lewis and Bronsted type catalysts, respectively.Before adsorption of the pyridine, the zeolite is pretreated under secondary vacuum at 450 ° C. for 10 h with an intermediate plateau at 150 ° C. for 1 h, the pyridine is then adsorbed at 150 ° C. and then desorbed under secondary vacuum at this same temperature before taking the spectra.

Catalyst preparation

The modified zeolite may be, but is not limited to, for example, powder, ground powder, suspension, deagglomeration-treated suspension. Thus, for example, the modified zeolite may advantageously be slurried acidulated or not at a concentration adjusted to the final zeolite content referred to the support. This suspension commonly called a slip is then advantageously mixed with the precursors of the matrix.

)

According to a preferred method of preparation, the modified zeolite can advantageously be introduced during the shaping of the support with the elements that constitute the matrix. For example, according to this preferred embodiment of the present invention, the modified zeolite according to the invention is added to a wet alumina gel during the carrier shaping step.

One of the preferred methods of forming the carrier in the present invention is to knead at least one modified zeolite with a wet alumina gel for a few tens of minutes and then pass the resulting paste through a die to form extrudates with a diameter of between 0.4 and 4 mm.

0

According to another preferred method of preparation, the modified zeolite can be introduced during the synthesis of the matrix. For example, according to this preferred embodiment of the present invention, the modified zeolite is added during the synthesis of the silicoaluminum matrix; the zeolite may be added to a mixture of an acidic alumina compound with a fully soluble silica compound. The support can be shaped by any technique known to those skilled in the art. The shaping can be carried out for example by extrusion, pelletizing, by the method of coagulation in drop (oil-drop), by rotating plate granulation or by any other method well known to those skilled in the art.

At least one calcination may be performed after any of the steps of the preparation. The calcination treatment is usually carried out in air at a temperature of at least 150 ° C, preferably at least 300 ° C, more preferably at about 350 to 1000 ° C.

Group VIB elements and / or Group VIII elements and optionally at least one doping element selected from boron, silicon and phosphorus and optionally elements of groups IVB, or IB in the case where the active phase contains nickel reduced, can be optionally introduced, all or part, at any stage of the preparation, during the synthesis of the matrix, preferably during the shaping of the support, or very preferably after the shaping of the support by any method known to those skilled in the art. They can be introduced after forming the support and after or before the drying and calcining of the support.

According to a preferred embodiment of the present invention, all or part of the elements of groups VIB and / or elements of group VIII, and optionally at least one doping element chosen from boron, silicon and phosphorus and optionally elements of groups IVB , or IB in the case where the active phase contains reduced nickel, may be introduced during the shaping of the support, for example, during the kneading step of the modified zeolite with a wet alumina gel.

According to another preferred embodiment of the present invention, all or part of the elements of groups VIB and / or elements of group VIII and optionally at least one doping element chosen from boron, silicon and phosphorus and optionally elements of groups IVB , or IB in the case where the active phase contains reduced nickel, may be introduced by one or more impregnation operations of the shaped and calcined support, by a solution containing the precursors of said elements. In a preferred manner, the support is impregnated with an aqueous solution. The impregnation of the support is preferably carried out by the "dry" impregnation method well known to those skilled in the art. In the case where the catalyst of the present invention contains a non-noble metal of group VIII, the metals of group VIII are preferably introduced by one or more impregnation operations of the shaped and calcined support, after those of group VI B or at the same time as these.

In the case where the catalyst of the present invention contains a noble metal of group VIII, the metals of group VIII are preferably introduced by one or more impregnation operations of the shaped and calcined support.

)

According to another preferred embodiment of the present invention, the deposition of the elements of group IVB or group IB can also be carried out simultaneously using, for example, a solution containing a tin salt or a copper salt.

According to another preferred embodiment of the present invention, the deposition of boron and silicon can also be carried out simultaneously using, for example, a solution containing a boron salt and a silicon-type silicon compound.

When at least one doping element, P and / or B and / or Si, is introduced, its distribution and location can be determined by techniques such as the Castaing microprobe (distribution profile of the various elements), electron microscopy by transmission coupled to an EDX analysis (energy dispersive analysis) of the catalyst components, or even by establishing a distribution map of the elements present in the catalyst by electron microprobe.

5

For example, among the sources of molybdenum and tungsten, it is possible to use oxides and hydroxides, molybdic and tungstic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, ammonium tungstate, phosphomolybdic acid, phosphotungstic acid and their salts, silicomolybdic acid, silicotungstic acid and their salts. Oxides and ammonium salts such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate are preferably used.

Sources of non-noble group VIII elements that can be used are well known to those skilled in the art. For example, for non-noble metals, use will be made of nitrates, sulphates, hydroxides, phosphates and halides, for example chlorides, bromides and fluorides, carboxylates such as acetates and carbonates.

The noble element sources of group VIII which can advantageously be used are well known to those skilled in the art. For the noble metals halides are used, for example chlorides, nitrates, acids such as hexachloroplatinic acid, hydroxides, oxychlorides such as ammoniacal oxychloride ruthenium. It is also advantageous to use cationic complexes such as ammonium salts when it is desired to deposit the metal on the Y-type zeolite by cation exchange.

The noble metals of Group VIII of the catalyst of the present invention may advantageously be present in whole or in part in metallic and / or oxide form.

The element (s) promoter (s) chosen (s) in the group formed by silicon, boron and phosphorus can advantageously be introduced by one or more impregnation operations with excess solution on the calcined precursor.

The boron source may advantageously be boric acid, preferably orthoboric acid H3B03, biborate or ammonium pentaborate, boron oxide, boric esters. Boron may for example be introduced in the form of a mixture of boric acid, hydrogen peroxide and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the family of pyridine and quinolines and compounds of the pyrrole family. Boron may be introduced for example by a boric acid solution in a water / alcohol mixture. The preferred phosphorus source is orthophosphoric acid H 3 PO 4, but its salts and esters such as ammonium phosphates are also suitable. The phosphorus may for example be introduced in the form of a mixture of phosphoric acid and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the family of pyridine and quinolines and compounds of the pyrrole family.

Many sources of silicon can advantageously be employed. Thus, it is possible to use ethyl orthosilicate Si (OEt) 4, siloxanes, polysiloxanes, silicones, silicone emulsions, halide silicates, such as ammonium fluorosilicate (NH4) 2SiF6 or fluorosilicate. sodium Na2SiF6. Silicomolybdic acid and its salts, silicotungstic acid and its salts can also be advantageously employed. Silicon may advantageously be added for example by impregnation of ethyl silicate in solution in a water / alcohol mixture. Silicon can be added for example by impregnation of a silicon-type silicon compound or silicic acid suspended in water.

Group IB source materials that can be used are well known to those skilled in the art. For example, among copper sources, Cu (N0 ₃ ) ₂ copper nitrate can be used.

The sources of Group IVB elements that can be used are well known to those skilled in the art. For example, among the sources of tin, tin chloride SnCl _{2 can be used} .

D

The catalysts used in the process according to the invention advantageously have the form of spheres or extrudates. It is however advantageous that 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 are cylindrical (which may be hollow or not), cylindrical 5 twisted, multilobed (2, 3, 4 or 5 lobes for example), rings. The cylindrical shape is preferably used, but any other shape may be used. The catalysts according to the invention may optionally be manufactured and used in the form of crushed powder, tablets, rings, balls, wheels.

In the case where the hydroisomerization catalyst contains at least one noble metal, the noble metal contained in said hydroisomerization catalyst must advantageously be reduced. One of the preferred methods for conducting the reduction of the metal is hydrogen treatment at a temperature between 150 ° C and 650 ° C and a total pressure of between 1 and 250 bar. For example, a reduction consists of a plateau at 150 ° C of

Two hours and then a rise in temperature up to 450 ° C at a rate of 1 ° C / min and then a two-hour stage at 450 ° C; throughout this reduction step, the hydrogen flow rate is 1000 normal m ³ hydrogen / m ³ catalyst and the total pressure kept constant at 1 bar. Any ex-situ reduction method can advantageously be considered.

0

According to step c) of hydroisomerization of the process according to the invention, at least a portion of the hydrocarbon base resulting from step b) is brought into contact, in the presence of hydrogen with said hydroisomerization catalyst, with operating temperatures and pressures advantageously allowing for hydroisomerization of the non-converting filler. This means that the hydroisomerisation is carried out with a converting the 150 ° C + fraction to 150 ° C ^* fraction less than 20% by weight, preferably less than 10% by weight and very preferably less than 5% by weight.

Thus, according to the invention, step c) of hydroisomerization of the process according to the invention operates at a temperature of between 150 and 500 ° C., preferably between 150 ° C. and 450 ° C., and very preferred, between 200 and 450 ° C, at a pressure of between 1 MPa and 10 MPa, preferably between 2 MPa and 10 MPa and very preferably between 1 MPa and 9 MPa, at an hourly space velocity advantageously between 0 1 hr ^"1 to 10 ^{h" 1,} preferably between 0.2 and 7 h ^"1 and very preferably between 0.5 and 5 ^h" 0 ^1, with a hydrogen flow rate such that the volume ratio hydrogen / hydrocarbons is advantageously between 70 and 1000 Nm ³ / m ³ of filler, between 100 and 1000 normal m ³ of hydrogen per m ³ of filler and preferably between 150 and 1000 normal m ³ of hydrogen per m ³ charge.

Preferably, the optional hydroisomerization step operates cocurrently.

5

The products, diesel base and kerosene, obtained according to the process according to the invention and in particular after hydroisomerization are endowed with excellent characteristics.

The diesel base obtained, after mixing with a petroleum diesel fuel derived from renewable fuels such as coal or lignocellulosic biomass, and / or with an additive, is of excellent quality:

- Its sulfur content is less than 10 ppm by weight.

its total aromatics content is less than 5% by weight, and the polyaromatic content is less than 2% by weight.

the cetane number is excellent, greater than 55.

5 - the density is less than 840 kg / m3, and most often greater than 820 kg / m3.

- Its kinematic viscosity at 40 ° C is 2 to 8 mm2 / s.

- its cold-holding properties are compatible with current standards, with a filterability limit of less than -15 ° C and a cloud point below -5 ° C.

The kerosene cut obtained, after mixing with a petroleum kerosene derived from renewable fuels such as coal or lignocellulosic biomass and / or with an additive, has the following characteristics:

- a density of between 775 and 840 kg / m3

a viscosity at -20 ° C. of less than 8 mm 2 / s

Î5 - a point of disappearance of crystals lower than -47 ° C - a flash point higher than 38 ° C

- a smoke point greater than 25 mm.

Examples

> Step a): hdrdrocessing

In a temperature controlled reactor so as to provide isothermal and fixed bed operation charged with 190 ml of hydrotreatment catalyst based on nickel and molybdenum, having a nickel oxide content equal to 3% by weight, and a content in molybdenum oxide equal to 16% by weight and a P ₂ O _{5 content} equal to 6%, the catalyst

3 being previously sulphurized, 170 g / h of pre-refined rapeseed oil with a density of 920 kg / m ³ having a sulfur content of less than 10 ppm by weight, with a cetane number of 35 and whose composition is detailed below:

5 700 Nm ³ of hydrogen / m ³ of feed are introduced into the reactor maintained at a

temperature of 300 ° C and a pressure of 5 MPa.

Step b): separation of the effluent from step a).

The totality of the hydrotreated effluent from step a) is separated so as to recover the

: 0 hydrogen-rich gases and a hydrocarbon base.

Step c): Hydroisomerization of the hydrotreated effluent from step b) on a catalyst according to the invention

Preparation of the initial dealuminated zeolite Y Z1 according to the invention

100 g of the crude synthetic NaY zeolite is exchanged 3 times with a 1N solution of NH ₄ NO ₃ at a temperature of 80 ° C. to obtain the NH ₄ Y zeolite. The NH ₄ Y zeolite then undergoes a 700 ° heat treatment. C for 3h in the presence of 60% water vapor. The heat treatment is done using a gas flow of water vapor and air of 2 L / h / g zeolite. The zeolite then undergoes treatment with a solution of 2 mol / l HN0 ₃ (V / P = 15) for 3 hours at 80 ° C. The zeolite is finally filtered and dried for 12 hours at 120 ° C. The zeolite is then in dealuminated HY form.

The dealuminated Z zeolite obtained Z1 has an overall atomic ratio Si / Al = 6.2 measured by X-ray fluorescence, a weight fraction of extra-initial network aluminum atom equal to 37% by weight relative to the total mass of aluminum. present in the zeolite and measured by NMR of aluminum, an initial mesoporous volume measured by nitrogen porosimetry equal to 0.15 ml. g ^"1 , and an initial crystal parameter at ₀ of the elemental mesh equal to 24.35 A, measured by XRD.

Preparation of the modified zeolite Z2 according to the invention used in the catalyst according to the invention.

100 g of dealuminated Z zeolites with an overall Si / Al = 6.2 atomic ratio measured by FX prepared in Example 1 are mixed with 1 L of 0.1 N sodium hydroxide (NaOH) solution at 60 ° C. C for 30min. After cooling rapidly in ice water, the suspension is then filtered and the zeolite is washed at 50 ° C and dried overnight at 120 ° C. The modified dealuminated Y zeolite is then exchanged 3 times with a 1N solution of NH ₄ NO ₃ at a temperature of 80 ° C. to obtain the partially exchanged NH ₄ ⁺ form. The zeolite is finally calcined at 450 ° C. for 2 hours under an air flow of 1 L / h / g of zeolite. Characterizations of zeolite Z2 measured by nitrogen adsorption / desorption, X-ray fluorescence, ²⁷ AI and ²⁹ Si NMR and pyridine adsorption followed by IR are given in Table 1.

Table 1: Characterization of the samples.

zeolite Z2

zeolite Z1

modified

initial

in accordance with

unmodified

the invention

Si / Global AI (FX) 6.2 4.7

% Alvi (NMR) 37 33

SBET (m ² / g) 778,743

Flight. mesoporous (ml / g) 0.28 (+ 86%)

Flight. microporous (ml / g) 0.28 0.25 (-11%)

Brønsted acidity (a.u.) 4.3 5.4 (+ 25%)

Preparation of catalysts

The catalyst supports according to the invention containing the modified zeolite (Z2 conforming) or not (Z1) are manufactured using 19.5 g of zeolite mixed with 80.5 g of a matrix composed of ultrafine tabular boehmite or gel of alumina marketed under the name SB3 by Condéa Chemie Gmbh. This powder mixture is then mixed with an aqueous solution containing nitric acid at 66% by weight (7% by weight of acid per gram of dry gel) and then kneaded for 15 minutes. The kneaded paste is then extruded through a die having a diameter of 1.2 mm. The extrudates are then calcined at 500 ° C. for 2 hours in air.

The carrier extrudates thus prepared are dry impregnated with a solution of a mixture of ammonium heptamolybdate and nickel nitrate and calcined in air at 550 ° C. in situ in the reactor. The oxide weight contents of the catalysts obtained are shown in Table 2.

Catalysts C1 and C2 are thus prepared from unmodified zeolites Z1 and modified according to the invention Z2. The oxide weight contents of the catalysts obtained are shown in Table 2. Table 2: Characteristics of the catalysts.

C1 C2

Catalyst reference

(non-compliant) (compliant)

Zeolite at the base of Z1 no

Z2 modified

modified catalyst

Mo0 ₃ (% wt) 12.3 12.3

NiO (% wt) 3 3, 1

Si0 ₂ (% wt) overall 14.3 13.9

100% complement

(mostly

70.4 70.4

composed of Al ₂ 0 ₃ ,%

weight)

The hydrotreated hydrocarbon effluent obtained at the end of step b / is hydroisomerized with hydrogen lost in a hydroisomerisation reactor under the operating conditions below:

WH (load volume / catalyst volume / hour) = 1 hr ^-1

total working pressure: 5 MPa

temperature: 300 ° C

- Hydrogen / charge ratio: 700 normal liters / liter

The reaction temperature is set so as to reach a gross conversion (denoted by CB) equal to 70% by weight.

50 ppm by weight of dimethyl disulfide is added to the feed in order to simulate the partial pressures of H ₂ S and to maintain the catalyst in sulphurized form. The charge thus prepared is injected into the hydroisomerisation test unit which comprises a fixed-bed reactor with up-flow of the charge ("up-flow") into which 100 ml of catalyst is introduced. The catalyst is sulphurized with a straight-run diesel / DMDS and aniline mixture up to 320 ° C. It should be noted that any in situ or ex situ sulphurization method is suitable. Once the sulphurization is complete, the charge can be transformed. The operating conditions of the test unit are indicated above.

The yield of jet fuel (kerosene, 150-250 ° C. cut, below Yt Kero) is equal to the weight percentage of compounds having a boiling point of between 150 and 250 ° C. in the effluents. The gas oil yield (250 ° C + fraction) is equal to the weight percentage of compounds having a boiling point greater than 250 ° C in the effluents.

The temperature of 300 ° C. is adjusted so as to have a conversion of the fraction 150 ° C ⁺ fraction 150 ° C ^" less than 5% by weight during the hydroisomerization in the case where the hydroisomerization catalyst used in the Step c) of the process according to the invention contains the modified zeolite according to the invention In Table 3, we have reported the temperature the yields of kerosene and gas oil for the catalysts described in the examples above.

Table 3: Catalytic Activities of Catalysts in Hydroisomerization.

Yield kerosene Yield diesel (% wt) (% wt)

C1 non-compliant

(prepared from 30 57

Z1 unmodified)

C2 compliant

(prepared from g 34

61

Z3 modified according to

the invention)

At a temperature of 300 ° C., the process employing, in the hydroisomerization step c), a catalyst containing an unmodified zeolite, produces a light 150 × -cutting at a yield of 13% and therefore the production of middle distillate at a lower yield compared with the implementation in step c) hydroisomerization of the process according to the invention, a catalyst containing a zeolite modified according to the invention. The method according to the invention thus demonstrates that the catalyst containing a zeolite modified according to the invention and used in said process according to the invention is more active than the non-compliant catalysts to obtain a conversion level of the fraction 150 ° C + less than 5% by weight, while making it possible to obtain higher middle distillate yields, and thus a better selectivity in middle distillates, compared to a hydroisomerisation process using a non-catalytic catalyst. conformant containing a zeolite unmodified or modified in a manner not in accordance with the invention.

Claims

A process for treating renewable feedstock feeds comprising the steps of: a) hydrotreating said feedstock in the presence of a fixed bed catalyst comprising a hydro-dehydrogenating function comprising at least one Group VIII metal and / or

) VIB group, taken alone or in mixture and a support selected from the group formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals, said step hydrotreater operating at a temperature between 200 and 450 ° C, at a pressure of between 1 MPa and 10 MPa, at a space velocity of between 0.1 h ^"1 and 10 h ^{" 1} and in the presence of a total amount of hydrogen

Mixed with the feed such that the hydrogen / feed ratio is between 70 and 1000 Nm ³ of hydrogen / m ³ of feed, b) separation from the effluent from step a) of hydrogen, gases and at least one hydrocarbon base,

D

c) hydroisomerization of at least a portion of said hydrocarbon base resulting from step b) in the presence of a fixed bed hydroisomerization catalyst, said catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the Group VIB and Group VIII of the Periodic Table and a carrier comprising at least one

5 minus a dealuminated Y zeolite having an initial overall silicon to aluminum atomic ratio of between 2.5 and 20, a weight fraction of extra-initial network aluminum atom greater than 10%, relative to the total mass of the aluminum present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry greater than 0.07 ml.g-1, and an initial crystal parameter aO of the elemental mesh of between 24.38 Å and

24.30 A, said zeolite being modified by a ') a basic treatment step consisting of the mixture of said dealuminated zeolite Y with a basic aqueous solution, said basic aqueous solution being a solution of basic compounds chosen from alkaline bases and the non-alkaline strong bases and at least one heat treatment step c ') carried out at a temperature of between 200 and 700 ° C., said hydroisomerisation step

5 being carried out at a temperature between 150 and 500 ° C, at a pressure of between 1 MPa and 10 MPa, at a space velocity of between 0.1 and 10 h -1 and in the presence of a total amount of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1000. Nm3 / m3 of load,

D) separating from the effluent from step c) hydrogen, gases and at least one gas oil base and a kerosene base.

2. The process as claimed in claim 1, in which the metals of group VIII of said catalyst used in step c) of hydroisomerization are chosen from noble metals of group VIII, and are chosen from platinum and palladium, taken alone or in mixed.

0

3. Method according to one of claims 1 or 2 wherein the noble metal content of said catalyst used in step c) of hydroisomerisation is between 0.01 and 10% by weight relative to the total weight of said catalyst.

4. The process of claim 1 wherein said catalyst used in the hydroisomerization step c) comprises at least one Group VIB metal in combination with at least one Group VIII non-noble metal, the Group VIB metal content. being, in oxide equivalent, between 5 and 40% by weight relative to the total mass of said catalyst and the non-noble metal content of group VIII being, in oxide equivalent, between

0 0.5 and 10% by weight relative to the total mass of said catalyst.

5. Method according to one of claims 1 to 4 wherein the dealuminated initial zeolite Y has before being modified an initial overall atomic ratio of silicon on aluminum of between 2.7 and 10.0.

5

6. Method according to one of claims 1 to 5 wherein the dealuminated initial zeolite Y has before modification a weight fraction of extra large initial network aluminum atom 30% by weight relative to the total mass of the aluminum present in the zeolite.

10

7. Method according to one of claims 1 to 6 wherein the alkali bases used in the basic aqueous solution of step a ') are selected from alkali carbonates and alkali hydroxides, and non-alkaline bases are chosen among quaternary ammoniums, taken alone or as a mixture

The method of claim 7 wherein the aqueous solution is a solution of sodium carbonate or sodium hydroxide. ^< ~

9. Method according to one of claims 1 to 8 wherein in the case where the basic treatment step a ') consists of mixing said dealuminated initial zeolite Y with a basic aqueous solution of compounds selected from alkaline bases, the process for modifying said zeolite comprises a step b ') of at least one partial or total exchange of said alkaline cations belonging to groups IA and IIA of the periodic table introduced during step a), by NH ₄ ⁺ cations .

10. Method according to one of claims 1 to 8 wherein in the case where the basic treatment step a ') consists of mixing said dealuminated initial zeolite Y with a basic aqueous solution of compounds selected from non-alkaline bases. chosen from quaternary ammoniums, taken alone or as a mixture, the process for modifying said dealuminated initial zeolite Y does not comprise step b ') of at least one partial or total intermediate exchange.

11. Method according to one of claims 1 to 10 wherein the charges from renewable sources are chosen from oils and fats of vegetable or animal origin, or mixtures of such fillers, containing triglycerides and / or fatty acids. and / or esters and said vegetable oils which may be raw or refined, wholly or in part, and derived from the following plants: rapeseed, sunflower, soya, palm, palm kernel, olive, coconut, jatropha, and animal fats being selected from fat or fat composed of residues from the food industry or from the food service industries.