METHOD FOR PREPARING AN ALUMINUM COMPRISING LANTHANUM FOR THE HYDROTASHING OF DISTILLATES UNDER VACUUM

Abstract

The present invention relates to the preparation of a mesoporous lanthanum-containing alumina formed from a boehmite gel, in which at least one lanthanum precursor is added during the precipitation step of at least one aluminum salt to form a boehmite gel and / or during the shaping step of the resulting boehmite gel. The lanthanum-containing alumina according to the invention, due to its advantageous properties, can be used as a catalyst support in all refining processes as well as an adsorbent, particularly for catalytic processes treating hydrocarbon fractions such as vacuum hydrotreating of distillates.

Description

Title of the invention: METHOD FOR PREPARING AN ALUMINUM COMPRISING LANTHANUM FOR THE HYDROTHERAPY OF DISTILLATES UNDER VACUUM technical field

[0001] The present invention relates to the preparation of a mesoporous alumina containing lanthanum formed from a boehmite gel in which at least one lanthanum precursor is added in the precipitation step of at least one aluminum salt to form a boehmite gel and / or in the shaping step of the boehmite gel obtained.

[0002] Lanthanum-containing alumina according to the invention, due to its advantageous properties, can be used as a catalyst support in all refining processes as well as an adsorbent, particularly for catalytic processes treating hydrocarbon fractions such as vacuum hydrotreating of distillates. Prior art

[0003] US Patent 2005054738 describes the preparation of a FISCHER-TROPSCH catalyst and an alumina-based catalyst support with a surface at least partially covered with a layer of a rare-earth oxide, such as lanthanum oxide. The rare-earth oxide layer prevents the deactivation of the active phase by interaction with the alumina-based support. The rare-earth oxide is introduced by dry impregnation of an alumina-based support or an alumina precursor, followed by a calcination step at temperatures between 800 and 1400°C. The amount of rare earth in the final material is 1–15% (metal equivalent). The catalyst support has a surface area between 40 and 150 m² / g and a pore volume between 0.1 and 0.5 ml / g.

[0004] Patent application CN106140314 describes the preparation of a hydrotreating catalyst optionally containing lanthanum. The catalyst is obtained by mixing alumina, aluminum hydroxide (boehmite, pseudo-boehmite) with an aqueous solution of a lanthanum salt followed by an autoclaving step (100°C and 24 hours), filtration and drying steps, and extrusion, drying and calcination steps.

[0005] Patent application CN106362757 describes the preparation of a hydrotreating and hydrodesulfurization catalyst optionally containing lanthanum. The catalyst is obtained by mixing alumina and aluminum hydroxide (boehmite, pseudo-boehmite), followed by an autoclaving step (100°C and 24 hours) with the optional addition of a lanthanum salt after the autoclaving step, and further steps of filtration and drying, extrusion, drying and calcination stages.

[0006] Patent application CN106362758 describes the preparation of a hydrotreating and hydrodesulfurization catalyst optionally containing lanthanum. The catalyst is obtained by mixing alumina and aluminum hydroxide (boehmite, pseudo-boehmite), followed by an autoclaving step with the optional addition of a lanthanum salt after the autoclaving step, filtration and drying steps, and extrusion, drying, and calcination steps.

[0007] Patent application CN108067243 describes the preparation of a hydrotreating catalyst optionally containing lanthanum. The lanthanum is introduced by impregnation after the shaping step followed by a drying and calcination step.

[0008] Patent IN263574 describes the preparation of a hydrotreating catalyst containing a rare earth element, preferably cerium. The rare earth element is introduced during the shaping step of the alumina-type support, preferably at a concentration of 0.5 to 2% relative to the alumina. The support is prepared by mixing alumina with a rare earth salt and nitric acid.

[0009] Patent JP4817405 describes the preparation of a lanthanum-containing hydrotreating catalyst. The lanthanum is introduced by vacuum impregnation after the shaping step of the gamma alumina support followed by a drying and calcination step.

[0010] US patent 5482616 describes the preparation of a hydrogenation / dehydrogenation catalyst containing a metal oxide. The metal oxide is selected from the following oxides: silver, lanthanum, antimony, nickel, bismuth, cadmium, lead, tin, vanadium, calcium, strontium, barium, cobalt, copper, tungsten, zinc, molybdenum, manganese, and iron. The metal oxide is introduced into the support by slurry impregnation with a salt of the corresponding metal, followed by an evaporation step at 90°C, a filtration / washing step, drying, and treatment under high-temperature hydrogen.

[0011] Surprisingly, the applicant discovered that a boehmite gel prepared according to a process comprising at least one precipitation step in which a soluble lanthanum source may optionally be introduced and in which at least 25% by weight of boehmite gel in Al2O3 equivalent relative to the total quantity of boehmite gel in A12O3 equivalent formed at the end of said gel preparation process, are formed from the first precipitation step, and optionally a final heat treatment step, could be shaped with optionally a soluble lanthanum salt to obtain a mesoporous alumina containing lanthanum and exhibiting an innovative pore distribution which makes it very attractive for use as an adsorbent and / or catalyst support and in particular for the hydrotreating of heavy hydrocarbon cuts such as vacuum distillates. Summary and significance of the invention

[0012] The present invention relates to a process for preparing an alumina containing lanthanum, said process comprising at least the following steps:

[0013] a) at least one or more precipitation step(s) of a boehmite gel, in an aqueous reaction medium, of at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonia, sodium hydroxide and potassium hydroxide and of at least one acidic precursor selected from aluminium sulfate, aluminium chloride, aluminium nitrate, sulfuric acid, hydrochloric acid, and nitric acid, wherein at least one of the basic or acid precursors comprises aluminium, the relative flow rate of the acid and basic precursors is selected so as to obtain a pH of the reaction medium between 8.5 and 10.5 and the flow rate of the aluminium-containing acid and basic precursor(s) is adjusted so as to obtain a degree of advancement of said first step between 15 and 100% and preferably between 20 and 100%,the rate of advancement being defined as the proportion of boehmite gel formed in A12O3 equivalent during said first precipitation step relative to the total quantity of boehmite gel formed in A12O3 equivalent at the end of the or each of the precipitation steps implemented, said precipitation step operating at a temperature between 20 and 90°C, and for a duration between 2 minutes and 40 minutes, ,

[0014] b) optionally one or more heat treatment steps of the suspension obtained at the end of step a) at a temperature between 70 and 100°C for a period between 30 minutes and 5 hours,

[0015] c) a filtration step of the suspension obtained at the end of step a) or possibly at the end of step b) of heat treatment, followed by at least one washing step of the boehmite gel obtained,

[0016] d) a drying step of the boehmite gel obtained at the end of step c) to obtain a powder,

[0017] e) a step of shaping the powder obtained at the end of step d) to obtain the raw material,

[0018] f) a drying step of the raw material obtained in shaping step e) carried out at a temperature between 20 and 200°C and for a duration between 1 hour and 3 weeks to obtain a dried raw material,

[0019] g) a heat treatment step of the dried raw material obtained at the end of step f) at a temperature between 500 and 1000°C, with or without an airflow containing up to 60% water by volume,

[0020] said process being characterized in that at least one lanthanum salt is added in at least one or more step(s) a) of precipitation and / or in step e) of shaping and / or optionally in one or more step b) of heat treatment.

[0021] The process according to the present invention allows the obtaining of an alumina comprising lanthanum having textural properties suitable for its use as a catalyst support.

[0022] The process of the present invention may also advantageously include at least one step of deposition of at least one metal of group VIII, and / or at least one metal of group VIB, and / or at least one dopant selected from boron, phosphorus and silicon and preferably phosphorus and optionally of at least one organic additive on said alumina containing lanthanum prepared according to the invention.

[0023] Another object of the present invention is a hydrotreating process for feedstocks selected from hydrocarbon cuts having a distillation range between 250°C and 600°C, preferably vacuum distillates, and renewable feedstocks selected from vegetable oils, algal oils, cooking oils, animal fats, fresh or used, alone or in mixtures, and feedstocks from the reprocessing of biomass / plastics / tires / and household waste, alone or in mixtures, said process employing a catalyst comprising at least one metal from group VIII, at least one metal from group VIB, optionally at least one dopant selected from boron, phosphorus and silicon and preferably phosphorus and optionally at least one organic additive and a support comprising and preferably consisting of said alumina comprising lanthanum prepared according to the preparation process according to the invention.

[0024] An advantage of the invention is that it provides a new, inexpensive method for preparing lanthanum-containing alumina compared to conventional prior art alumina preparation methods, such as sol-gel processes. In particular, the method according to the invention does not involve autoclaving, and each unit step of the method is economically attractive and has already been proven on an industrial scale.

[0025] Finally, another advantage of the preparation process according to the invention is to allow the obtaining of catalyst supports and associated catalysts exhibiting unparalleled performance compared to catalysts containing or not containing lanthanum described in the prior art.In particular, the hydrotreating activity of feeds selected from hydrocarbon cuts having a distillation range between 250°C and 600°C and renewable feeds selected from vegetable oils, algal oils, cooking oils, animal fats, fresh or used, alone or in mixtures, and feeds from the reprocessing of biomass / plastics / tires / and household waste, alone or in mixtures, and in particular the hydrotreating of vacuum distillate cuts of a catalyst comprising the alumina support comprising lanthanum prepared according to the invention is significantly superior to that of catalysts containing or not lanthanum, prepared according to any prior art method. known to the person in the trade.

[0026] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC Press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals in columns 8, 9 and 10 according to the new IUP AC classification, and group VIB to the metals in column 6.

[0027] In the following text, the expressions "between ... and ..." and "between ... and ..." are equivalent and mean that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such clarification will be provided by the present invention.

[0028] In this description, the expression "greater than..." is understood as strictly greater than, and symbolized by the sign ">", and the expression "less than" as strictly less than, and symbolized by the sign "<".

[0029] Definitions and measurement methods.

[0030] The alumina according to the present invention has a specific pore distribution, where the macroporous and mesoporous volumes are measured by mercury intrusion and the microporous volume is measured by nitrogen adsorption.

[0031] By "macropores" we mean pores whose opening is greater than 50 nm.

[0032] By "mesopores", we mean pores whose opening is between 2 nm and 50 nm, inclusive.

[0033] By "micropores" we mean pores whose opening is strictly less than 2 nm.

[0034] In the following description of the invention, the pore distribution measured by mercury porosimetry is determined according to ASTM D4284-83 at a maximum pressure of 4000 bar (400 MPa), using a surface tension of 484 dyne / cm and a contact angle of 140°. The wetting angle was taken to be 140° following the recommendations of the book "Techniques de l'ingénieur, traité analyse et caractérisation, P 1050-5, written by Jean Charpin and Bernard Rasneur".

[0035] The value from which mercury fills all intergranular voids is set at 0.2 MPa, and beyond this is considered that mercury penetrates the pores of alumina.

[0036] In order to obtain better accuracy, the value of the total pore volume corresponds to the value of the total pore volume measured by mercury porosimetry measured on the sample less the value of the total pore volume measured by mercury porosimetry measured on the same sample for a pressure corresponding to 30 psi (approximately 0.2 MPa).

[0037] The macroporous volume is defined as the cumulative volume of mercury introduced at a pressure between 0.2 MPa and 30 MPa, corresponding to the volume contained in pores with an apparent diameter greater than 50 nm.

[0038] The mesoporous volume is defined as the cumulative volume of mercury introduced at a pressure between 30 MPa and 400 MPa, corresponding to the volume contained in pores with an apparent diameter between 2 and 50 nm.

[0039] The volume of the micropores is measured by nitrogen porosimetry. The quantitative analysis of the microporosity is carried out using the "t" method (Lippens-De Boer method, 1965) which corresponds to a transform of the initial adsorption isotherm as described in the book "Adsorption by powders and porous solids. Principles, methodology and applications" written by F. Rouquérol, J. Rouquérol and K. Sing, Academie Press, 1999.

[0040] The median diameter of the mesopores (Dp in nm) is also defined as a diameter such that all pores smaller than this diameter constitute 50% of the mesoporous volume, measured by mercury porosimetry.

[0041] The pore distribution measured by nitrogen adsorption was determined using the Barrett-Joyner-Halenda (BJH) model. The nitrogen adsorption-desorption isotherm according to the BJH model is described in the journal *The Journal of the American Society*, 73, 373, (1951), written by E.P. Barrett, L.G. Joyner, and P.P. Halenda. In the following description of the invention, the nitrogen adsorption volume is understood to be the volume measured for P / Po = 0.99, the pressure at which it is assumed that nitrogen has filled all the pores.

[0042] In the following description of the invention, specific surface area means the specific surface area BET determined by nitrogen adsorption in accordance with ASTM D 3663-78 established from the BRUNAUER-EMMETT-TELLER method described in the periodical "The Journal of American Society", 60, 309, (1938).

[0043] X-ray diffraction on boehmite gels was carried out using the classical powder method with a diffractometer.

[0044] The Scherrer formula is a formula used in X-ray diffraction on polycrystalline powders or samples that relates the full width at half maximum (FWHM) of the diffraction peaks to the size of the crystallites. It is described in detail in the reference: Appl. Cryst. (1978). 11, 102-113 Scherrer after sixty years: A survey and some new results in the determination of crystallite size, J.I. Langford and A.J.C. Wilson. Description of the invention

[0045] Step a) of precipitation

[0046] According to the invention, said preparation process comprises at least one or more step(s) a) of precipitating a boehmite gel in an aqueous reaction medium containing at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonia, sodium hydroxide and potassium hydroxide and at least one acidic precursor selected from sulfate of aluminium, aluminium chloride, aluminium nitrate, sulfuric acid, hydrochloric acid, and nitric acid, in which at least one of the basic or acid precursors comprises aluminium, the relative flow rate of the acid and basic precursors is chosen so as to obtain a pH of the reaction medium between 8.5 and 10.5 and the flow rate of the acid and basic precursor(s) containing aluminium is set so as to obtain a degree of advancement of the first step between 15 and 100% and preferably between 20 and 100%, the degree of advancement being defined as the proportion of boehmite gel formed in A12O3 equivalent during said precipitation step a) or each of the precipitation steps implemented relative to the total quantity of boehmite gel in A12O3 equivalent formed at the end of the precipitation step(s) and more generally at the end of the steps of preparation of the boehmite gel,said step a) operating at a temperature between 20 and 80°C, and for a duration between 2 and 40 minutes.

[0047] Generally speaking, the "progress rate" of the nth precipitation step means the percentage of boehmite gel formed in A12O3 equivalent in said nth step, relative to the total quantity of boehmite gel formed at the end of all the precipitation steps and more generally at the end of the boehmite gel preparation steps.

[0048] Said nth precipitation step generally allows obtaining a boehmite gel suspension having an Al2O3 concentration between 20 and 100 g / l, preferably between 20 and 80 g / l, preferably between 20 and 50 g / l.

[0049] The mixing in the aqueous reaction medium of at least one basic precursor and at least one acidic precursor requires either that at least the basic precursor or the acidic precursor includes aluminium, or that both the basic and acidic precursors include aluminium.

[0050] Basic precursors comprising aluminum are sodium aluminate and potassium aluminate. The preferred basic precursor is sodium aluminate.

[0051] Acid precursors comprising aluminum are aluminum sulfate, aluminum chloride, and aluminum nitrate. The preferred acid precursor is aluminum sulfate.

[0052] Preferably, the basic and acid precursor(s) are added in said first precipitation step a) in aqueous solutions.

[0053] Preferably, the aqueous reaction medium is water.

[0054] Preferably, said step a) operates under agitation.

[0055] Preferably, said step a) is carried out in the absence of organic additive.

[0056] According to the invention, at least one lanthanum salt is added in at least one or more step(s) a) of precipitation and / or in step e) of shaping.

[0057] Said lanthanum salt, preferably soluble in said reaction medium of said step a) is chosen from lanthanum nitrate, lanthanum chloride, lanthanum acetate or any other lanthanum salt soluble in said reaction medium.

[0058] Preferably, the reaction medium for step a) is water. The preferred soluble lanthanum salt is lanthanum nitrate.

[0059] At least part and preferably all of the desired quantity of lanthanum salt is added during said step(s) a) of precipitation.

[0060] Preferably the lanthanum salt is introduced in full in the said step(s) a).

[0061] In the case where said process according to the invention comprises several precipitation steps a) the lanthanum salt can advantageously be added in each of the precipitation steps carried out and preferably the lanthanum salt is added in the first precipitation step.

[0062] The quantity of lanthanum salt added in said step a) is adjusted so that the final alumina obtained comprises a lanthanum element content of between 1 and 15% weight preferably between 1.3 and 10% and even more preferably between 1.5 and 6%, relative to the total weight of said alumina in A12O3 equivalent.

[0063] The acid and basic precursors, whether they contain aluminum or not, are mixed, preferably in solution, in the aqueous reaction medium which may contain the soluble lanthanum salt, in proportions such that the pH of the resulting suspension is between 8.5 and 10.5.

[0064] According to the invention, it is the relative flow rate of the acidic and basic precursors, whether they contain aluminum or not, that is chosen so as to obtain a pH of the reaction medium between 8.5 and 10.5.

[0065] Preferably, said step a) of precipitation is carried out at a pH between 8.5 and 10 and most preferably between 8.7 and 9.9.

[0066] The acidic and basic precursors are also mixed in quantities sufficient to obtain a suspension containing the desired amount of boehmite gel, depending on the final boehmite gel concentration to be achieved. In particular, said step a) or each of the precipitation steps implemented allows obtaining 15 to 100% by weight of boehmite gel in Al₂O₃ equivalent relative to the total amount of boehmite gel formed at the end of the precipitation step(s). According to the invention, the flow rate of the aluminum-containing acidic and basic precursor(s) is adjusted, depending on the duration of step a), so as to obtain a precipitation step a) completion rate of between 15 and 100%, and preferably between 20 and 100%.

[0067] In the event that the progress rate obtained at the end of step a) of precipitation is less than 100%, at least a second precipitation step is necessary to in order to increase the quantity of boehmite gel formed. In the case where a second precipitation step is implemented, the rate of advancement is defined as the proportion of boehmite gel formed in A12O3 equivalent during this second precipitation step relative to the total quantity of boehmite gel formed in A12O3 equivalent at the end of both precipitation steps of the preparation process according to the invention and more generally at the end of the boehmite gel preparation steps.

[0068] Thus, depending on the target concentration of boehmite gel at the end of the precipitation step(s), preferably between 20 and 100 g / l, the quantities of aluminium to be supplied by the acidic and / or basic precursors are calculated and the flow rate of the precursors is adjusted according to the concentration of said precursors in aluminium added, the quantity of water added to the reaction medium and the rate of advancement required for the precipitation step(s).

[0069] The flow rates of the acidic and / or basic precursor(s) containing aluminium depend on the size of the reactor used and thus on the amount of water added to the reaction medium.

[0070] Preferably, said step a) and preferably each of the precipitation steps implemented is (are) carried out at a temperature between 20 and 90°C, preferably between 25 and 70°C, more preferably between 30 and 65°C.

[0071] In the case where said preparation process according to the invention comprises two precipitation steps, the precipitation step a) is advantageously carried out at a temperature lower than the temperature of the second precipitation step.

[0072] Preferably, said step a) and preferably each of the precipitation steps implemented is (are) carried out for a duration of between 2 and 40 minutes, and preferably from 5 to 35 minutes.

[0073] In the embodiment where several precipitation steps are implemented, preferably, between each precipitation step, a temperature increase can be carried out.

[0074] Said temperature rise can advantageously be carried out at a temperature between 20 and 90°C, preferably between 30 and 80°C, preferably between 30 and 70°C and most preferably between 40 and 65°C.

[0075] In this case, said intermediate temperature rise is preferably implemented for a period of between 5 and 45 minutes and preferably between 7 and 35 minutes.

[0076] Said intermediate temperature rise is advantageously implemented according to all heating methods known to a person skilled in the art.

[0077] Step b) of heat treatment of the optional suspension

[0078] Said preparation process may optionally comprise one or more steps b) of heat treatment of the suspension obtained at the end of step a) the said heat treatment step(s) operating at a temperature between 70 and 100°C for a period of between 30 minutes and 5 hours.

[0079] One or more steps b) may advantageously be implemented in the case where only one precipitation step is implemented in the process according to the invention.

[0080] In the case where several precipitation steps a) are implemented, one or more heat treatment steps b) may advantageously be implemented at the end of the last precipitation step a).

[0081] In the case where a heat treatment step of the suspension obtained at the end of step a) is implemented, at least one preferably soluble lanthanum salt may optionally be added to the reaction medium during said heat treatment step b).

[0082] Preferably, the lanthanum salt is chosen from lanthanum nitrate, lanthanum chloride, lanthanum acetate, or any other lanthanum salt soluble in said reaction medium and preferably in water. The preferred soluble lanthanum salt is lanthanum nitrate.

[0083] All or part of the desired quantity of lanthanum salt may advantageously be added in said step(s) b), in the case where at least one step b) is carried out.

[0084] The quantity of lanthanum salt added in said step b) when implemented, is adjusted so that the final alumina obtained comprises a lanthanum element content between 1 and 15% weight preferably between 1.3 and 10% and even more preferably between 1.5 and 6%, relative to the total weight of said alumina in A12O3 equivalent.

[0085] Preferably, said heat treatment step b) is a ripening step.

[0086] Preferably, said step(s) b) of heat treatment operate(s) at a temperature between 70 and 100°C and preferably between 70 and 90°C.

[0087] Preferably, the said heat treatment step(s) is / are carried out for a period of between 30 minutes and 5 hours.

[0088] Said ripening stage is advantageously implemented according to all heating methods known to those skilled in the art.

[0089] Step c) of filtration

[0090] According to the invention, the process according to the invention comprises a step c) of filtering the suspension obtained at the end of step a) or optionally at the end of step b) of heat treatment, followed by at least one step of washing the gel obtained. Said filtration step is carried out according to methods known to those skilled in the art.

[0091] Said filtration step is advantageously followed by at least one water washing step and preferably by one to three washing steps, with a quantity of water equal to the quantity of precipitate filtered.

[0092] Step d) of drying

[0093] According to the invention, the boehmite gel obtained at the end of step c) of filtration, is dried in a step d) of drying to obtain a powder.

[0094] Said drying step is advantageously carried out at a temperature between 20 and 200°C, preferably between 40 and 150°C, and for a duration between 1 hour and 3 weeks, and preferably between 1 hour and 48 hours, or by spraying.

[0095] In the case where said drying step d) is carried out by spray drying, the cake obtained at the end of the heat treatment step, possibly followed by a filtration step, is resuspended. This suspension is then sprayed as fine droplets into a vertical cylindrical chamber in contact with a stream of hot air in order to evaporate the water according to the principle well known to those skilled in the art. The resulting powder is carried by the heat flow to a cyclone or a baghouse filter, which separates the air from the powder. Preferably, in the case where said drying step d) is carried out by spray drying, the spray drying is performed according to the operating procedure described in the publication Asep Bayu Dani Nandiyanto, Kikuo Okuyama, Advanced Powder Technology, 22, 1-19, 2011.

[0096] The boehmite obtained in powder form is advantageously composed of crystallites whose size, obtained by the Scherrer formula in X-ray diffraction along the crystallographic directions (020) and (120) is respectively between 2 and 40 nm and between 2 and 50 nm.

[0097] The boehmite thus prepared makes it possible to facilitate the shaping step of said gel according to all the methods known to the person skilled in the art and in particular by mixing extrusion, by granulation and by the technique known as "oil drop" according to Anglo-Saxon terminology.

[0098] Step e) of formatting

[0099] According to the invention, the powder obtained at the end of step d) of drying is shaped in a step e) to obtain a raw material.

[0100] Raw material means material that has been shaped and has not undergone any heat treatment steps.

[0101] Preferably, said shaping step e) is carried out by extrusion mixing, pelletizing, the oil-drop coagulation method, rotary plate granulation or any other method well known to those skilled in the art.

[0102] Preferably, said shaping step e) is carried out by mixing extrusion.

[0103] According to the invention, at least one lanthanum salt is added in at least one or more step(s) a) of precipitation and / or in step e) of shaping.

[0104] In the case where a lanthanum salt is added in said step e) of shaping the powder obtained at the end of step d), the lanthanum salt is preferably soluble and added as an aqueous solution.

[0105] Preferably, the lanthanum salt is chosen from lanthanum nitrate, lanthanum chloride, lanthanum acetate, or any other water-soluble lanthanum salt. The preferred soluble lanthanum salt is lanthanum nitrate.

[0106] At least part and preferably all of the desired quantity of lanthanum salt is added during said shaping step e).

[0107] In a preferred embodiment, said shaping step e) is carried out by mixing-extrusion, said step e) being carried out with a total acid content, expressed as a percentage by weight relative to the mass of dried powder introduced in step e) of between 0 and 10% and a neutralization content expressed as a percentage by weight of base relative to the amount of acid introduced in said step e) of between 0 and 200%.

[0108] Preferably, said step e) is carried out with a total acid content, expressed as a percentage relative to the mass of dried gel introduced in step e) of between 0 and 8%, and most preferably between 0 and 6% and a neutralization content expressed as a percentage by weight of base relative to the amount of acid introduced in said step e) of between 0 and 150%, preferably between 0 and 130%, most preferably between 0 and 100%, most preferably between 0 and 80% and most preferably between 0 and 60%.

[0109] Preferably, the acid used in step e) is chosen from nitric acid and carboxylic acids, preferably chosen from acetic acid, citric acid and butyric acid, and preferably nitric acid.

[0110] Preferably, the base used in step e) is chosen from among the inorganic bases selected from sodium hydroxide, potassium hydroxide, and ammonia, and the organic bases in solution selected from among the amines and quaternary ammonium compounds. Preferably, the organic bases in solution are chosen from among the alkylethanolamines and ethoxylated alkylamines. The organic bases are preferably used in aqueous solution.

[0111] Most preferably, said base is ammonia and preferably ammonia in aqueous solution (NH40H+ H2O).

[0112] Lanthanum salt can advantageously be added at any time during shaping step e).

[0113] For example, said lanthanum salt may advantageously be added before, and / or after the addition of acid, and / or at the same time as the addition of acid, and / or before the addition of base, and / or after and / or at the same time as the basic addition.

[0114] Drying step f)

[0115] According to the invention, the raw material obtained at the end of step e) of shaping, is dried in a step f) of drying carried out at a temperature between 20 and 200°C preferably between 40 and 150°C and for a period of between 1 hour and 3 weeks and preferably between 1 hour and 48 hours to obtain a dried raw material.

[0116] Step g) of heat treatment

[0117] According to the invention, the dried raw material obtained at the end of step f) of drying then undergoes a step g) of heat treatment at a temperature between 500 and 1000°C, for a period of between 2 and 10 h, in the presence or not of an airflow containing up to 60% water by volume.

[0118] Preferably, said heat treatment step g) operates at a temperature between 520°C and 850°C, preferably between 520 and 800°C and even more preferably between 530 and 750°C.

[0119] Preferably, said heat treatment step g) operates for a duration between 1h and 12h, preferably between 1h30 and 100 and even more preferably between 2h and 8h.

[0120] Said heat treatment step g allows the transition of boehmite to the final alumina, and allows adjustment of the final porous texture of the alumina prepared according to the invention and which contains Lanthanum.

[0121] The lanthanum content in the material and preferably the alumina obtained at the end of step g) is preferably between 1 and 15% more preferably between 1.3 and 10% and even more preferably between 1.5 and 6%, relative to the total weight of said alumina in A12O3 equivalent.

[0122] The preparation process according to the invention allows obtaining a mesoporous alumina containing lanthanum and exhibiting controlled mesoporosity with good thermal and chemical stability, having a centered, uniform and controlled mesopore size distribution, and a calibrated specific surface area and pore volume, and in particular mesoporous volume.

[0123] The process according to the present invention allows the obtaining of an alumina comprising lanthanum having textural properties suitable for its use as a catalyst support.

[0124] Preferably, said alumina comprises a lanthanum content of between 1 and 15%, preferably between 1.3 and 10% and even more preferably between 1.5 and 6%, relative to the total weight of said alumina in A12O3 equivalent.

[0125] Said mesoporous alumina containing lanthanum prepared according to the process of the invention is preferably devoid of micropores. The absence of micropores is measured and verified by nitrogen adsorption.

[0126] The mesoporous alumina containing lanthanum prepared according to the process of the invention advantageously has a specific surface area BET of between 50 and 450 m2 / g, preferably of between 100 and 400 m2 / g, preferably of between 200 and 400 m2 / g, and most preferably of between 220 and 380 m2 / g, and a mesoporous volume greater than or equal to 0.5 ml / g, preferably of between 0.55 and 0.85 ml / g, most preferably of between 0.60 and 0.80 ml / g and even more preferably of between 0.65 and 0.78 ml / g.

[0127] Preferably, the total porous volume of said lanthanum-containing alumina measured by mercury porosimetry is between 0.6 and 0.9 ml / g.

[0128] Preferably, the percentage of volume contained in pores of size between 2 and 50 nm relative to the total pore volume of said lanthanum-containing alumina measured by mercury porosimetry, is greater than 90% and preferably greater than 95%.

[0129] The median diameter of the mesopores measured by mercury porosimetry of said lanthanum-containing alumina, determined by volume, is advantageously between 7 and 13.5 nm and preferably between 8.5 and 12.5 nm, most preferably between 9.0 and 12.3 nm, even more preferably between 9.5 and 12.0 nm.

[0130] Preferably, the percentage of the mesoporous volume of pores having a diameter between 8 and 20 nm measured by mercury porosimetry is between 70 and 100%, preferably it is between 75 and 100% and even more preferably it is between 80 and 100%.

[0131] Preferably, the alumina according to the invention is a non-mesostructured alumina.

[0132] Said mesoporous alumina containing lanthanum has a sulfur content of between 0.001% and 0.4% by weight and a sodium content of between 0.001% and 0.04% by weight, the weight percentages being expressed in relation to the total mass of boehmite gel in its A12O3 form.

[0133] Preferably, the lanthanum-containing alumina obtained at the end of the process according to the invention is in the form of irregular and non-spherical beads, extrudates, pellets or agglomerates whose specific shape may result from a crushing step.

[0134] Preferably, said lanthanum-containing alumina prepared according to the invention is used as a catalyst support. The form of the support comprising said lanthanum-containing alumina is that of extrudates with a diameter of between 0.8 and 3 mm, preferably between 1.2 and 2.6 mm. The geometry of the extrudates may be cylindrical, trilobular, quadrilobular, or any other advantageous shape depending on the desired application.

[0135] A catalyst can advantageously be prepared from alumina containing lanthanum prepared according to the invention and used as a support for said catalyst.

[0136] One or more elements chosen in relation to the desired catalytic application are then deposited on the surface of said support according to any method known to the person skilled in the art.

[0137] The process according to the invention may advantageously include a step h) of deposition onto said lanthanum-containing alumina obtained from step g) of at least one metal from Group VIII and / or at least one metal from Group VIB of the periodic table of elements and / or a dopant element selected from boron, phosphorus, and silicon, and preferably phosphorus, and optionally of at least one organic additive to obtain a catalyst. If an organic additive is deposited, its deposition is followed by a drying step without calcination. If no organic additive has been deposited, the metal deposition is followed by a drying step and optionally a calcination step.

[0138] The metal(s) of group VIII and / or at least one metal of group VIB may advantageously be introduced in one or more steps and preferably by dry or excess impregnation.

[0139] In a preferred mode, at least one metal from group VIII, at least one metal from group VIB, at least one dopant selected from boron, phosphorus and silicon and preferably phosphorus and optionally at least one organic additive are deposited on said support.

[0140] The group VIB metal present in the active phase of the catalyst is preferably chosen from molybdenum and tungsten. The group VIII metal present in the active phase of the catalyst is preferably chosen from cobalt, nickel, and mixtures of these two elements. The active phase of the catalyst is preferably chosen from the group formed by the combination of nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten, and nickel-cobalt-molybdenum, and most preferably the active phase consists of nickel and molybdenum, nickel and tungsten, or a nickel-molybdenum-tungsten combination.

[0141] The content of group VIII metal in the catalyst is less than 20% by weight, preferably between 0.03 and 15% by weight, most preferably between 0.5 and 10% by weight, and even more preferably between 1 and 8% by weight expressed as group VIII metal oxide relative to the total weight of the catalyst.

[0142] The content of group VIB metal in the catalyst is between 1 and 50% by weight, preferably between 5 and 40% by weight, and more preferably between 10 and 35% by weight and even more preferably between 15 and 30% by weight expressed as group VIB metal oxide relative to the total weight of the catalyst.

[0143] The molar ratio of group VIII metal to group VIB metal of the catalyst is generally less than 1, preferably between 0.01 and 0.75, and most preferably between 0.10 and 0.60 and even more preferably between 0.20 and 0.50.

[0144] Optionally, the catalyst may also have a phosphorus content generally less than 15% by weight, preferably between 0.1 and 10% by weight, most preferably between 0.1 and 8% by weight, and even more preferably between 0.2 and 6% by weight of P2O5 relative to the total weight of fresh catalyst.

[0145] Furthermore, in the case where the catalyst includes phosphorus, the phosphorus / (metal of group VIB) molar ratio is generally between 0.02 and 1, preferably between 0.04 and 0.8, and most preferably between 0.1 and 0.75.

[0146] The catalyst may also further comprise at least one organic compound containing oxygen and / or nitrogen and / or sulfur prior to sulfidation. Such additives are known to those skilled in the art. Generally, the organic compound is chosen from among compounds having one or more chemical functions selected from among a carboxylic acid, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide, or compounds including a furanic ring, or sugars.

[0147] The content of organic compound(s) containing oxygen and / or nitrogen and / or sulfur on the catalyst is between 1 and 30% by weight, preferably between 1.5 and 25% by weight, and more preferably between 2 and 20% by weight relative to the total weight of the fresh catalyst. The organic compound(s) introduced during one of the catalyst preparation steps are introduced in a quantity corresponding to:

[0148] - to a compound molar ratio added by metal(s) of group VIB present(s) in the regenerated catalyst having a concentration between 0.01 and 2.0 mol / mol, preferably between 0.01 and 1.5 mol / mol, most preferably between 0.01 and 1.0 mol / mol, and most preferably between 0.02 and 0.08 mol / mol,

[0149] - and to a compound molar ratio added by group VIII metal(s) present in the regenerated catalyst between 0.02 and 6.0 mol / mol, preferably between 0.03 and 4.0 mol / mol, preferably between 0.04 and 3.0 mol / mol, and most preferably between 0.05 and 0.4 mol / mol.

[0150] When several compounds are present, the different molar ratios are added together so that the sum of the added compounds corresponds to the values ​​above.

[0151] The oxygen-containing organic compound may be one or more of a carboxylic acid, an alcohol, an aldehyde, or an ester. By way of example, the oxygen-containing organic compound may be one or more of the group consisting of ethylene glycol, glycerol, polyethylene glycol (with a molecular weight of 200 to 1500), acetophenone, 2,4-pentanedione, pentanol, acetic acid, maleic acid, oxalic acid, tartaric acid, formic acid, citric acid and C1-C4 dialkyl succinate. When the organic compound is a carboxylic organic acid, it is preferably chosen from acetic acid, maleic acid, malic acid, malonic acid, gluconic acid, tartaric acid, citric acid, γ-ketovaleric acid, lactic acid, pyruvic acid, ascorbic acid, oxalic acid or succinic acid,

[0152] According to a variant of the invention, when an organic compound is present, the fresh catalyst has not undergone calcination during its preparation, i.e. the impregnated catalytic precursor has not been subjected to a heat treatment step at a temperature above 200°C under an inert atmosphere or under an atmosphere containing oxygen, in the presence of water or not.

[0153] Another object of the present invention is a hydrotreating process for hydrocarbon cuts employing a catalyst containing an alumina comprising lanthanum, said alumina being prepared according to the preparation process according to the invention.

[0154] In particular, another object of the present invention is a hydrotreating process for feedstocks selected from hydrocarbon cuts having a distillation range between 250°C and 600°C, preferably vacuum distillates, and renewable feedstocks selected from vegetable oils, algal oils, cooking oils, animal fats, fresh or used, alone or in mixtures, and feedstocks from the reprocessing of biomass / plastics / tires / and household waste, alone or in mixtures, said process employing a catalyst comprising at least one metal from group VIII, at least one metal from group VIB, optionally at least one dopant selected from boron, phosphorus and silicon and preferably phosphorus and optionally at least one organic additive and a support comprising and preferably consisting of said alumina comprising lanthanum prepared according to the preparation process according to the invention.

[0155] Before its use in a hydrocarbon fraction hydrotreating process, the catalyst is generally subjected to sulfidation to obtain the metals in their sulfided or partially sulfided forms as described below. This activation or sulfidation step is carried out by methods well known to those skilled in the art, and advantageously under a sulfur-reducing atmosphere in the presence of hydrogen and hydrogen sulfide.

[0156] Said catalyst is advantageously sulfided ex situ or in situ. The sulfiding agents are H2S gas, elemental sulfur, CS2, mercaptans, sulfides and / or polysulfides, hydrocarbon fractions with a boiling point below 400°C. containing sulfur compounds or any other sulfur-containing compound used for activating hydrocarbon feedstocks to sulfide the catalyst. These sulfur-containing compounds are advantageously selected from alkyl disulfides such as, for example, dimethyl disulfide (DMDS), alkyl sulfides such as, for example, dimethyl sulfide, thiols such as, for example, n-butyl mercaptan (or 1-butanethiol), and polysulfide compounds of the tertiononylpolysulfide type. The catalyst may also be sulfided by the sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfided in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock. Most preferably, the catalyst is sulfided in situ in the presence of a hydrocarbon feedstock to which dimethyl disulfide has been added.

[0157] Use of a catalyst prepared from a support prepared according to the invention

[0158] Preferably, the so-called heavy hydrocarbon fillers are chosen from among the Charges with a weighted average temperature (WAT) above 380°C. The WAT is defined as the temperature at which 5%, 50%, and 70% of the charge volume distill, according to the following formula: WAT = (T 5% + 2 x T 50% + 4 x T 70%) / 7. The WAT is calculated from simulated distillation values. The WAT of the charge is above 380°C and preferably below 600°C, and even more preferably below 580°C.

[0159] According to the invention, the treated hydrocarbon feedstock preferably has a distillation range between 250°C and 600°C, preferably between 300 and 580°C.

[0160] Said hydrocarbon feedstock is advantageously chosen from LCO or HCO (Light Cycle Oil or Heavy Cycle Oil according to Anglo-Saxon terminology (light or heavy gas oils from a catalytic cracking unit)), vacuum distillates for example gas oils from the direct distillation of crude oil or from conversion units such as catalytic cracking, coker or visbreaking, feedstocks from aromatic extraction units, lubricating oil bases or from solvent dewaxing of lubricating oil bases, distillates from desulfurization or hydroconversion processes in fixed bed or bubbling bed of atmospheric residues and / or vacuum residues and / or deasphalted oils, or the feedstock may be a deasphalted oil.

[0161] Preferably, said hydrocarbon charge is a vacuum distillate.

[0162] Any hydrocarbon feed containing sulfur and nitrogen compounds that inhibit hydrotreating, and with a TMP similar to that of a vacuum distillate cut, can be used in the process of the present invention. The hydrocarbon feed can be of any chemical nature, that is to say, have any distribution among the different chemical families, in particular paraffins, olefins, naphthenes, and aromatics.

[0163] Said hydrocarbon feedstock comprises nitrogenous and / or sulfurous organic molecules. The nitrogenous organic molecules are either basic, such as amines, anilines, pyridines, acridines, quinolines and their derivatives, or neutral, such as pyrroles, indoles, carbazoles and their derivatives. It is primarily the basic nitrogenous molecules that inhibit hydrotreating catalysts, and in particular additive catalysts.

[0164] The nitrogen content is greater than or equal to 250 ppm, preferably between 400 and 10,000 ppm by weight, more preferably between 700 and 4,000 ppm by weight, and even more preferably between 1,000 and 4,000 ppm by weight. The basic nitrogen content comprises at least one-quarter of the total nitrogen content. The basic nitrogen content is generally greater than or equal to 60 ppm, more preferably between 175 and 1,000 ppm by weight, and even more preferably between 250 and 1,000 ppm by weight.

[0165] The sulfur content in the feed is generally between 0.01 and 5% by weight, preferably between 0.2 and 4% by weight and even more preferably between 0.5 and 3% by weight.

[0166] Said hydrocarbon feedstock may advantageously contain metals, in particular nickel and vanadium. The cumulative nickel and vanadium content of said hydrocarbon feedstock, treated according to the hydrocracking process according to the invention, is preferably less than 1 ppm by weight.

[0167] The asphaltene content of said hydrocarbon filler is generally less than 3000 ppm, preferably less than 1000 ppm, even more preferably less than 200 ppm.

[0168] The processed feedstock generally contains resins, preferably with a resin content greater than 1 wt%, and more preferably greater than 5 wt%. The resin content is measured according to ASTM D 2007-11.

[0169] According to the invention, said feed treated in the hydrotreatment process is chosen from renewable feeds selected from vegetable oils, algal oils, cooking oils, animal fats, fresh or used, alone or in mixtures, and feeds from the reprocessing of biomass / plastics / tires / and household waste, alone or in mixtures.

[0170] Said charge treated according to the hydrotreating process of the invention may also be a mixture of the aforementioned charges previously mentioned.

[0171] The catalyst prepared from the lanthanum-containing alumina support according to the invention can then be used in one, two, or more reactors. It is generally used for implementation in a fixed bed.

[0172] The operating conditions used for the operation, preferably in a fixed bed, of the catalyst prepared from the lanthanum-containing alumina support according to the invention correspond to those generally used for a hydrotreating process and are the following: the temperature is advantageously between 200 and 450°C, and preferably between 300 and 400°C, the pressure is advantageously between 0.5 and 30 MPa, and preferably between 5 and 20 MPa, the hourly volumetric velocity (defined as the ratio of the volumetric flow rate of charge to the volume of the catalyst per hour) is advantageously between 0.1 and 20 h-1 and preferably between 0.2 and 5 h-1, and the hydrogen / charge ratio expressed as volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid charge is advantageously between 50 1 / 1 and 2000 1 / 1.

[0173] The invention is illustrated by the following examples which are in no way limiting. Examples:

[0174] Example 1 according to the invention (addition of La (2%) to the first precipitation step):

[0175] Alumina is prepared according to a preparation process according to the invention, with the addition of the soluble lanthanum salt in the first coprecipitation step. Agitation is maintained at 350 rpm throughout the synthesis.

[0176] The synthesis of boehmite gel is carried out according to a preparation process according to the invention in a 5 L reactor and for a final suspension volume of 3.5 L in two precipitation steps.

[0177] The final concentration of boehmite gel considered in the target form A12O3 is 36 g / l. The quantity of water added to the reactor before the first co-precipitation is 1158.25 mL water and the quantity of lanthanum salt, La(NO3)3*6H2O is 8.75 g.

[0178] A first co-precipitation step in water of aluminum sulfate A12(SO4) and sodium aluminate NaAlOO is carried out at 40°C and pH=9.4 for a duration of 8 minutes. The concentrations of the aluminum precursors used are as follows: A12(SO4) = 102 g / L as A12O3 and NaAlOO = 155 g / L as A12O3.

[0179] An aluminium sulfate solution A12(SO4) is added continuously to the reactor containing water and lanthanum salt for 8 minutes at a rate of 13.8 ml / min simultaneously with a sodium aluminate solution NaAlOO at a rate of 17.5 ml / min in order to adjust the pH to a value of 9.4. The temperature of the reaction medium is maintained at 40°C.

[0180] A suspension containing a precipitate of boehmite gel is obtained.

[0181] The progress rate of the first precipitation stage is 25%.

[0182] The resulting suspension is then subjected to a temperature increase from 40 to 60°C in 30 minutes.

[0183] A second co-precipitation step of the resulting suspension is then carried out by adding aluminum sulfate Al₂(SO₄) at a concentration of 102 g / L as Al₂O₃ and sodium aluminate NaAlOO₄ at a concentration of 155 g / L as Al₂O₃. A solution Aluminium sulfate A12(SO4) is therefore added continuously to the heated suspension obtained at the end of the first precipitation step for 30 minutes at a rate of 10.3 ml / min simultaneously with a sodium aluminate NaAlOO solution at a rate of 14.2 ml / min in order to adjust the pH to a value of 9.7. The temperature of the reaction medium in the second step is maintained at 60°C.

[0184] These flow rates of acidic and basic precursors containing aluminium make it possible to obtain at the end of the second precipitation stage a rate of advancement of 75%, the cumulative rate of advancement of the first and second precipitation stages being equal to 100%.

[0185] A suspension containing a precipitate of boehmite gel containing lanthanum is obtained.

[0186] The resulting suspension is then filtered by water displacement over a sintered Buchner type tool and the resulting alumina gel is washed 3 times with 5 L of distilled water.

[0187] The characteristics of the boehmite gel thus obtained are summarized in Table 1.

[0188] Table 1: Characteristics of the boehmite gel obtained according to Example 1.

[0189] [Tables 1] Example 1: Size (020) (nm) 3.20 Size (120) (nm) 3.70

[0190] The lanthanum-containing boehmite gel obtained according to Example 1 was dried in a ventilated study at 120°C for 16 hours.

[0191] The dried boehmite gel is then introduced into a Brabender-type mixer. Acidified water with nitric acid, at a total acid concentration of 4%, expressed by weight relative to the mass of dried powder considered in the form Al₂O₃ introduced into the mixer, is added over 5 minutes during mixing at 20 rpm. Acid mixing is continued for 15 minutes. A neutralization step is then carried out by adding an ammonia solution to the mixer, at a neutralization concentration of 40%, expressed by weight of ammonia relative to the amount of nitric acid introduced into the mixer for the acidification step. Mixing is continued for 3 minutes.

[0192] The resulting paste is then extruded through a 2 mm trilobed die. The extrudates are dried at 100°C for 16 hours and then calcined for 4 hours at 650°C under a stream of water-free air. The alumina obtained exhibits the characteristic peaks of gamma alumina in X-ray diffraction. The textural characteristics of the lanthanum-containing gamma alumina formed are shown in Table 2:

[0193] Table 2: Characteristics of lanthanum-containing alumina A obtained according to example 1.

[0194] [Tables2] Example 1 SBET(m2 / g) 236 VPT (Hg) (ml / g) 0.77 Dp (Hg) (nm) 11.1% VP(Hg) between 8 and 20nm 82 Sodium Na (%) 0.0068 Sulfur S (%) 0.0863 Lanthanum La (%) 2.0

[0195] Example 2 according to the invention: (addition of La (5.1%) to the first precipitation step)

[0196] Alumina is prepared according to a preparation process according to the invention, with the addition of the soluble lanthanum salt in the first coprecipitation step. Agitation is maintained at 350 rpm throughout the synthesis.

[0197] The synthesis of boehmite gel is carried out according to a preparation process according to the invention in a 5 L reactor and for a final suspension volume of 3.5 L in two precipitation steps.

[0198] The final concentration of boehmite gel considered in the target form A12O3 is 36g / l. The quantity of water added to the reactor before the first co-precipitation is 1158.25 mL water and the quantity of lanthanum salt, La(NO3)3*6H2O, is 21.75 g.

[0199] A first co-precipitation step in water of aluminum sulfate A12(SO4) and sodium aluminate NaAlOO is carried out at 40°C and pH=9.4 for a duration of 8 minutes. The concentrations of the aluminum precursors used are as follows: A12(SO4) = 102 g / l as A12O3 and NaAlOO = 155 g / l as A12O3.

[0200] An aluminium sulfate solution A12(SO4) is added continuously to the reactor containing water and lanthanum salt for 8 minutes at a rate of 13.8 ml / min simultaneously with a sodium aluminate solution NaAlOO at a rate of 17.5 ml / min in order to adjust the pH to a value of 9.4. The temperature of the reaction medium is maintained at 40°C.

[0201] A suspension containing a precipitate of boehmite gel is obtained.

[0202] The progress rate of the first precipitation stage is 25%.

[0203] The resulting suspension is then subjected to a temperature increase from 40 to 60°C in 30 minutes.

[0204] A second co-precipitation step of the resulting suspension is then carried out by adding aluminum sulfate A12(SO4) at a concentration of 102 g / L as A12O3 and sodium aluminate NaAlOO at a concentration of 155 g / L as A12O3. A solution of aluminum sulfate A12(SO4) is therefore added continuously to the heated suspension obtained after the first precipitation step for 30 minutes at a rate of 10.3 mL / min simultaneously with a solution of sodium aluminate NaAlOO at a rate of 14.2 mL / min in order to adjust the pH to a value of 9.7. The temperature of the reaction medium in the second step is maintained at 60°C.

[0205] These flow rates of acidic and basic precursors containing aluminium make it possible to obtain at the end of the second precipitation stage a rate of advancement of 75%, the cumulative rate of advancement of the first and second precipitation stages being equal to 100%.

[0206] A suspension containing a precipitate of boehmite gel containing lanthanum is obtained.

[0207] The resulting suspension is then filtered by water displacement over a sintered Buchner type tool and the resulting alumina gel is washed 3 times with 5 L of distilled water.

[0208] The characteristics of the boehmite gel thus obtained are summarized in Table 3.

[0209] Table 3: Characteristics of the boehmite gel obtained according to Example 2.

[0210] [Tables3] Example 2: Size (020) (nm) 3.10 Size (120) (nm) 3.50

[0211] The lanthanum-containing boehmite gel obtained according to Example 2 was dried in a ventilated study at 120°C for 16 hours.

[0212] The dried boehmite gel is then introduced into a Brabender-type mixer. Acidified water with nitric acid, at a total acid concentration of 4%, expressed by weight relative to the mass of dried powder considered in the form Al₂O₃ introduced into the mixer, is added over 5 minutes during mixing at 20 rpm. Acid mixing is continued for 15 minutes. A neutralization step is then carried out by adding an ammonia solution to the mixer, at a neutralization concentration of 40%, expressed by weight of ammonia relative to the amount of nitric acid introduced into the mixer for the acidification step. Mixing is continued for 3 minutes.

[0213] The resulting paste is then extruded through a 2 mm trilobed die. The extrudates are dried at 100°C for 16 hours and then calcined for 4 hours at 650°C under a flow of dry air. The alumina obtained exhibits the characteristic peaks of a Gamma alumina in X-ray diffraction. The textural characteristics of the gamma alumina formed containing lanthanum are reported in Table 4:

[0214] Table 4: Characteristics of lanthanum-containing alumina B obtained according to example 2.

[0215] [Tables4] Example 2 SBET(m2 / g) 251 VPT (Hg) (ml / g) 0.78 Dp (Hg) (nm) 11.2% VP(Hg) between 8 and 20nm 92 Sodium Na (%) 0.0070 Sulfur S (%) 0.0823 Lanthanum La (%) 5.0

[0216] Example 3 according to the invention (addition of La (2%) at the first precipitation step + 3% at the shaping step):

[0217] Alumina is prepared according to a preparation process according to the invention, with the addition of the soluble lanthanum salt during the first co-precipitation and shaping. Agitation is maintained at 350 rpm throughout the synthesis.

[0218] The synthesis of boehmite gel is carried out according to a preparation process according to the invention in a 5 L reactor and for a final suspension volume of 3.5 L in two precipitation steps.

[0219] The final concentration of boehmite gel considered in the target form A12O3 is 36g / l. The quantity of water added to the reactor before the first co-precipitation is 1158.25 mL water and the quantity of lanthanum salt, La(NO3)3*6H2O, is 8.75 g.

[0220] A first co-precipitation step in water of aluminum sulfate A12(SO4) and sodium aluminate NaAlOO is carried out at 40°C and pH=9.4 for a duration of 8 minutes. The concentrations of the aluminum precursors used are as follows: A12(SO4) = 102 g / l as A12O3 and NaAlOO = 155 g / l as A12O3.

[0221] An aluminium sulfate solution A12(SO4) is added continuously to the reactor containing water and lanthanum salt for 8 minutes at a rate of 13.8 ml / min simultaneously with a sodium aluminate solution NaAlOO at a rate of 17.5 ml / min in order to adjust the pH to a value of 9.4. The temperature of the reaction medium is maintained at 40°C.

[0222] A suspension containing a precipitate of boehmite gel is obtained.

[0223] The progress rate of the first precipitation stage is 25%.

[0224] The resulting suspension is then subjected to a temperature increase from 40 to 60°C in 30 minutes.

[0225] A second co-precipitation step of the resulting suspension is then carried out by adding aluminum sulfate A12(SO4) at a concentration of 102 g / L as A12O3 and sodium aluminate NaAlOO at a concentration of 155 g / L as A12O3. A solution of aluminum sulfate A12(SO4) is therefore added continuously to the heated suspension obtained after the first precipitation step for 30 minutes at a rate of 10.3 mL / min simultaneously with a solution of sodium aluminate NaAlOO at a rate of 14.2 mL / min in order to adjust the pH to a value of 9.7. The temperature of the reaction medium in the second step is maintained at 60°C.

[0226] These flow rates of acidic and basic precursors containing aluminium make it possible to obtain at the end of the second precipitation stage a rate of advancement of 75%, the cumulative rate of advancement of the first and second precipitation stages being equal to 100%.

[0227] A suspension containing a precipitate of boehmite gel containing lanthanum is obtained.

[0228] The resulting suspension is then filtered by water displacement over a sintered Buchner type tool and the resulting alumina gel is washed 3 times with 5 L of distilled water.

[0229] The characteristics of the boehmite gel thus obtained are summarized in Table 5.

[0230] Table 5: Characteristics of the boehmite gel obtained according to Example 3.

[0231] [Tables5] Example 3: Size (020) (nm) 3.21 Size (120) (nm) 3.70

[0232] The lanthanum-containing boehmite gel obtained according to Example 3 was dried in a ventilated study at 120°C for 16 hours.

[0233] The dried boehmite gel is then introduced into a Brabender-type mixer. Acidified water with nitric acid at a total acid content of 4%, containing 13 g of lanthanum salt, La(NO3)3*6H2O, expressed by weight relative to the mass of dried powder considered in the form Al2O3, is added to the mixer over 5 minutes, during mixing at 20 rpm. Acid mixing is continued for 15 minutes. A neutralization step is then carried out by adding an ammonia solution to the mixer at a neutralization rate of 40%, expressed by weight of ammonia relative to the amount of nitric acid introduced into the mixer for the acidification step. Mixing is continued for 3 minutes.

[0234] The resulting paste is then extruded through a 2 mm trilobed die. The The extradermis obtained is dried at 100°C for 16 hours and then calcined for 4 hours at 650°C under a flow of dry air. The alumina obtained exhibits the characteristic peaks of gamma alumina in X-ray diffraction. The textural characteristics of the gamma alumina formed containing lanthanum are reported in Table 6:

[0235] Table 6: Characteristics of lanthanum-containing alumina C obtained according to example 3.

[0236] [Tableauxô] Example 3 SBET(m2 / g) 298 VPT (Hg) (ml / g) 0.76 Dp (Hg) (nm) 9.9% VP(Hg) between 8 and 20nm 84 Sodium Na (%) 0.0081 Sulfur S (%) 0.0963 Lanthanum La (%) 5.1

[0237] Example 4 according to the invention (addition of La (2%) at the shaping step):

[0238] Alumina is prepared according to a preparation process according to the invention with the addition of all of the soluble lanthanum salt at the shaping step. Agitation is maintained at 350 rpm throughout the synthesis.

[0239] The synthesis of boehmite gel is carried out according to a preparation process according to the invention in a 5 L reactor and for a final suspension volume of 3.5 L in two precipitation steps.

[0240] The final concentration of boehmite gel considered in the target form Al2O3 is 36 g / l. The quantity of water added to the reactor before the first co-precipitation is 1160 mL water.

[0241] A first co-precipitation step in water of aluminum sulfate A12(SO4) and sodium aluminate NaAlOO is carried out at 40°C and pH=9.4 for a duration of 8 minutes. The concentrations of the aluminum precursors used are as follows: A12(SO4) = 102 g / l as A12O3 and NaAlOO = 155 g / l as A12O3.

[0242] An aluminium sulfate solution A12(SO4) is added continuously to the reactor containing water for 8 minutes at a rate of 13.8 ml / min simultaneously with a sodium aluminate solution NaAlOO at a rate of 17.5 ml / min in order to adjust the pH to a value of 9.4. The temperature of the reaction medium is maintained at 40°C.

[0243] A suspension containing a precipitate of boehmite gel is obtained.

[0244] The progress rate of the first precipitation stage is 25%.

[0245] The resulting suspension is then subjected to a temperature increase from 40 to 60°C in 30 minutes.

[0246] A second co-precipitation step of the resulting suspension is then carried out by adding aluminum sulfate A12(SO4) at a concentration of 102 g / L as A12O3 and sodium aluminate NaAlOO at a concentration of 155 g / L as A12O3. A solution of aluminum sulfate A12(SO4) is therefore added continuously to the heated suspension obtained after the first precipitation step for 30 minutes at a rate of 10.3 mL / min simultaneously with a solution of sodium aluminate NaAlOO at a rate of 14.2 mL / min in order to adjust the pH to a value of 9.7. The temperature of the reaction medium in the second step is maintained at 60°C.

[0247] These flow rates of acidic and basic precursors containing aluminium make it possible to obtain at the end of the second precipitation stage a rate of advancement of 75%, the cumulative rate of advancement of the first and second precipitation stages being equal to 100%.

[0248] A suspension containing a precipitate of boehmite gel is obtained.

[0249] The resulting suspension is then filtered by water displacement over a sintered Buchner type tool and the resulting alumina gel is washed 3 times with 5 L of distilled water.

[0250] The characteristics of the boehmite gel thus obtained are summarized in Table 7.

[0251] Table 7: Characteristics of the boehmite gel obtained according to Example 4.

[0252] [Tables7] Example 4: Size (020) (nm) 3.21 Size (120) (nm) 3.71

[0253] The boehmite gel obtained according to Example 4 was dried in a ventilated study at 120°C for 16 hours.

[0254] The dried boehmite gel is then introduced into a Brabender-type mixer. Acidified water with nitric acid at a total acid content of 4%, containing 8.75 g of lanthanum salt, La(NO3)3*6H2O, expressed by weight relative to the mass of dried powder considered in the form A12O3 introduced into the mixer, is added over 5 minutes, during mixing at 20 rpm. Acid mixing is continued for 15 minutes. A neutralization step is then carried out by adding an ammonia solution to the mixer at a neutralization rate of 40%, expressed by weight of ammonia relative to the amount of nitric acid introduced into the mixer for the acidification step. Mixing is continued for 3 minutes.

[0255] The resulting paste is then extruded through a 2 mm trilobed die. The The extradermis obtained is dried at 100°C for 16 hours and then calcined for 4 hours at 650°C under a flow of dry air. The alumina obtained exhibits the characteristic peaks of gamma alumina in X-ray diffraction. The textural characteristics of the gamma alumina formed containing lanthanum are reported in Table 8:

[0256] Table 8: Characteristics of lanthanum-containing D alumina obtained according to example 4.

[0257] [Tables8] Example 4 SBET(m2 / g) 298 VPT (Hg) (ml / g) 0.75 Dp (Hg) (nm) 9.9% VP(Hg) between 8 and 20nm 82 Sodium Na (%) 0.078 Sulfur S (%) 0.0857 Lanthanum La (%) 2.0

[0258] Example 5 not in accordance with the invention (addition of La (2%) by impregnation on alumina):

[0259] Alumina is prepared according to a process not in accordance with the invention, in which all of the soluble lanthanum salt is added after the calcination heat treatment step and without any addition of lanthanum salt in the precipitation or shaping steps. Agitation is maintained at 350 rpm throughout the synthesis.

[0260] The synthesis of boehmite gel is carried out according to a prior art preparation process in a 5 L reactor and for a final suspension volume of 3.5 L in two precipitation steps.

[0261] The final concentration of boehmite gel considered in the target form Al2O3 is 36 g / l. The quantity of water added to the reactor before the first co-precipitation is 1160 mL water.

[0262] A first co-precipitation step in water of aluminum sulfate A12(SO4) and sodium aluminate NaAlOO is carried out at 40°C and pH=9.4 for a duration of 8 minutes. The concentrations of the aluminum precursors used are as follows: A12(SO4) = 102 g / l as A12O3 and NaAlOO = 155 g / l as A12O3.

[0263] An aluminum sulfate solution Al₂(SO₄) is continuously added to the reactor containing water for 8 minutes at a rate of 13.8 ml / min simultaneously with a sodium aluminate solution NaAlOO₄ at a rate of 17.5 ml / min so as to Adjust the pH to a value of 9.4. The temperature of the reaction medium is maintained at 40°C.

[0264] A suspension containing a precipitate of boehmite gel is obtained.

[0265] The progress rate of the first precipitation stage is 25%, the cumulative progress rate of the first and second precipitation stages being equal to 100%.

[0266] The resulting suspension is then subjected to a temperature increase from 40 to 60°C in 30 minutes.

[0267] A second co-precipitation step of the resulting suspension is then carried out by adding aluminum sulfate A12(SO4) at a concentration of 102 g / L as A12O3 and sodium aluminate NaAlOO at a concentration of 155 g / L as A12O3. A solution of aluminum sulfate A12(SO4) is therefore added continuously to the heated suspension obtained after the first precipitation step for 30 minutes at a rate of 10.3 mL / min simultaneously with a solution of sodium aluminate NaAlOO at a rate of 14.2 mL / min in order to adjust the pH to a value of 9.7. The temperature of the reaction medium in the second step is maintained at 60°C.

[0268] These flow rates of acidic and basic precursors containing aluminium make it possible to obtain at the end of the second precipitation stage an advancement rate of 75%.

[0269] The resulting suspension is then filtered by water displacement over a sintered Buchner type tool and the resulting alumina gel is washed 3 times with 5 L of distilled water.

[0270] The characteristics of the boehmite gel thus obtained are summarized in Table 9.

[0271] Table 9: Characteristics of the boehmite gel obtained according to Example 5.

[0272] [Tables9] Example 5: Size (020) (nm) 3.21 Size (120) (nm) 3.71

[0273] The boehmite gel obtained according to Example 5 was dried in a ventilated study at 120°C for 16 hours.

[0274] The dried boehmite gel is then introduced into a Brabender-type mixer. Water acidified with nitric acid to a total acid content of 4%, expressed by weight relative to the mass of dried gel considered in the form Al₂O₃ introduced into the mixer, is added over 5 minutes, during mixing at 20 rpm. Acid mixing is continued for 15 minutes. A neutralization step is then carried out by adding an ammonia solution to the mixer, at a neutralization content of 40%, expressed by weight of ammonia relative to the amount of nitric acid introduced into the mixer for the acidification step. The mixing is continued for 3 minutes.

[0275] The resulting paste is then extruded through a 2 mm trilobed die. The extrudates are dried at 100°C for 16 hours and then calcined for 4 hours at 650°C under a flow of dry air. The alumina obtained exhibits the characteristic peaks of gamma alumina in X-ray diffraction. The textural characteristics of the gamma alumina E formed are reported in Table 10:

[0276] Table 10: Characteristics of alumina E obtained according to example 5.

[0277] [TableauxlO] Example 5 SBET(m2 / g) 281 VPT (Hg) (ml / g) 0.73% VP(Hg) between 8 and 20nm 65 Dp (Hg) (nm) 9.8 Sodium Na (%) 0.068 Sulfur S (%) 0.0757

[0278] The alumina E extrudates obtained according to Example 5 are dry-impregnated with 95 mL of aqueous solution containing 8.75 g of lanthanum salt La(NO3)3*6H2O to obtain alumina F. After impregnation, the extrudates are kept at room temperature for 3 hours and then dried at 100°C for 16 hours and then calcined for 4 hours at 540°C to produce alumina F. Chemical analysis of these extrudates indicates a mass percentage of 2% of lanthanum relative to the mass of alumina in its Al2O3 form.

[0279] Example 6:

[0280] Supports A to F were dry-impregnated with an aqueous solution of nickel and molybdenum, targeting molybdenum and nickel contents of 30 wt% and 5 wt% respectively, expressed in their oxide form, corresponding to a theoretical molar ratio of 0.32. After a 6-hour maturation step in a closed system, the extrudates were dried at 160°C for 1 hour before being dry-impregnated again with an aqueous solution containing triethylene glycol (TEG) so that the TEG / Mo molar ratio was 0.8. A final drying was then applied to the extrudates for one hour in air at 90°C.

[0281] The catalysts thus obtained were then evaluated by hydrodeazotation of a distillate under vacuum with a TMP of 474°C (T5% = 389°C, T50% = 468°C, T70% = 498°C). The characteristics of the feed are as follows: sulfur 2.6 wt%, nitrogen 1350 ppm, basic nitrogen 392 ppm, resins 9.1 wt%.

[0282] The test is carried out in a flow-through fixed-bed isothermal pilot reactor, with fluids flowing from bottom to top.

[0283] After in situ sulfidation at 350 °C in the pressurized unit using the vacuum distillate of the test to which 2 wt% of dimethyl disulfide is added, the hydrotreating test was carried out under the following operating conditions: a total pressure of 150 bar (15 MPa), a WH of 2 h-1, an H2 / charge ratio of 1000 1 / h and a temperature of 380°C.

[0284] The following table shows the relative HDN percentage achieved in the reactor. The HDN percentage is calculated as follows: HDN (%) = (Nout - Nin) / Nin. The relative %HDN is normalized to a base of 100 corresponding to the reference case without Lanthanum.

[0285] [Tableauxll] Alumina support containing La A Conforms to the invention B Conforms to the invention C Conforms to the invention D Conforms to the invention E Not in accordance with the invention F Not in accordance with the invention %La 2% 5% 5% 2% / 2% Method of Lanthanum introduction Boehmite precipitation Boehmite precipitation Boehmite precipitation + Shaping - mixing Shaping - mixing / impregnation VPT Hg (ml / g) 0.77 0.78 0.76 0.75 0.73 0.72 Vmeso (ml / g) 0.77 0.77 0.76 0.74 0.73 0.72 %VP between 8 and 20nm 82 92 84 82 65 65 Median Dp (nm) 11.1 11.2 9.9 9.9 9.8 9.8 %NiO 4.9 4.8 5.0 4.9 4.9 5.0 %MoO3 29.8 30.1 30.0 29.8 29.7 29.9 %HDN 104 105 106 102 100 100

[0286] The following examples highlight the advantages of introducing 2 or 5% lanthanum during the preparation of an alumina support according to the process of the invention. Firstly, it is observed that when lanthanum is introduced during precipitation (supports A or B), during shaping (support D), or partly during precipitation and partly during shaping (support C), innovative textural characteristics are obtained. Indeed, under similar preparation conditions, but without added lanthanum (support E), the textural characteristics are very different. The addition of lanthanum according to the process of the invention makes it possible to maximize / optimize the useful porosity between 8 and 20 nm, while maintaining high specific surface areas.

[0287] Furthermore, the examples provided highlight the advantages of these novel textural distributions combined with the presence of lanthanum, since the performance of catalysts prepared identically from the various supports is significantly higher with supports A, B, C, and D of the invention than with the non-conforming support E, which does not contain lanthanum or the desired textural characteristics. Moreover, the catalyst prepared with support F, which, following impregnation, also contains lanthanum, does not perform any better than the one prepared with the lanthanum-free support E, thus highlighting the advantages of the preparation process according to the invention.

Claims

Demands

1. A process for preparing lanthanum-containing alumina, said process comprising at least the following steps: a) at least one or more steps of precipitating a boehmite gel, in an aqueous reaction medium, of at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonia, sodium hydroxide, and potassium hydroxide, and of at least one acidic precursor selected from aluminum sulfate, aluminum chloride, aluminum nitrate, sulfuric acid, hydrochloric acid, and nitric acid, wherein at least one of the basic or acidic precursors comprises aluminum, the relative flow rates of the acidic and basic precursors being chosen to obtain a pH of the reaction medium between 8.5 and 10.5, and the flow rate of the aluminum-containing acidic and basic precursor(s) being adjusted to obtain a degree of completion of said first step between 15 and 100%,the rate of advancement being defined as the proportion of boehmite gel formed in A12O3 equivalent during said first precipitation step relative to the total quantity of boehmite gel formed in A12O3 equivalent at the end of the precipitation step(s) implemented, said precipitation step operating at a temperature between 20 and 90°C, and for a duration between 2 minutes and 40 minutes, b) optionally one or more heat treatment step(s) of the suspension obtained at the end of step a) at a temperature between 70 and 100°C for a duration between 30 minutes and 5 hours, c) a filtration step of the suspension obtained at the end of step a) or optionally at the end of step b) of heat treatment, followed by at least one washing step of the boehmite gel obtained, d) a drying step of the boehmite gel obtained at the end of step c) to obtain a powder,e) a shaping step of the powder obtained at the end of step d) to obtain the raw material, f) a drying step of the raw material obtained in shaping step e) carried out at a temperature between 20 and 200°C and for a duration between 1 hour and 3 weeks to obtain a dried raw material, (g) a heat treatment step of the dried raw material obtained at the end of step (f) at a temperature between 500 and 1000°C, with or without an airflow containing up to 60% by volume of water, said process being characterized in that at least one lanthanum salt is added in at least one or more step(s) (a) of precipitation and / or in step (e) of shaping and / or optionally in one or more step(s) (b) of heat treatment.

2. A process according to claim 1 wherein said lanthanum salt is preferably soluble in said reaction medium of said step a) and is selected from lanthanum nitrate, lanthanum chloride, lanthanum acetate and preferably lanthanum nitrate.

3. A process according to claim 1 wherein lanthanum salt is added in each of the precipitation steps a) carried out and preferably lanthanum salt is added in the first precipitation step, in the case where said process comprises several precipitation steps a).

4. A method according to any one of the preceding claims wherein said drying step d) is carried out at a temperature between 20 and 200°C preferably between 40 and 150°C and for a period of between 1 hour and 3 weeks and preferably between 1 hour and 48 hours or by spraying.

5. A method according to any one of the preceding claims wherein said shaping step e) is carried out by mixing extrusion.

6. A process according to claim 5 wherein the lanthanum salt added in said step e) is selected from lanthanum nitrate, lanthanum chloride, lanthanum acetate and preferably lanthanum nitrate.

7. A process according to any one of claims 5 or 6 wherein said shaping step e) is carried out by mixing-extrusion, said step e) being carried out with a total acid content, expressed as a percentage by weight relative to the mass of dried powder introduced in step e) of between 0 and 10% and a neutralization content expressed as a percentage by weight of base relative to the amount of acid introduced in said step e) of between 0 and 200%.

8. A process according to any one of the preceding claims, wherein the lanthanum-containing mesoporous alumina prepared according to the process of any one of claims 1 to 7 has a BET specific surface area of ​​between 50 and 450 m² / g, a total pore volume measured by mercury porosimetry of between 0.6 and 0.9 ml / g, a percentage of volume included in pores of size between 2 and 50 nm relative to the total pore volume measured by mercury porosimetry, greater than 90%, a median diameter of mesopores measured by mercury porosimetry, determined in volume between 7 and 13.5 nm, and a percentage of the mesoporous volume of pores having a diameter between 8 and 20 nm measured by mercury porosimetry between 70 and 100%.

9. A method according to any one of the preceding claims wherein a step h) of deposition of at least one metal of group VIII and / or at least one metal of group VIB of the periodic table of elements optionally at least one dopant element selected from boron, phosphorus and silicon and preferably phosphorus and optionally at least one organic additive on said lanthanum-containing alumina from step g) is carried out.

10. A hydrotreating process for selected feedstocks from hydrocarbon cuts having a distillation range of between 250°C and 600°C, preferably vacuum distillates, and renewable feedstocks selected from vegetable oils, algal oils, cooking oils, animal fats, fresh or used, alone or in mixtures, and feedstocks from the reprocessing of biomass / plastics / tires / and household waste, alone or in mixtures, said process employing a catalyst comprising at least one metal from Group VIII, at least one metal from Group VIB, optionally at least one dopant selected from boron, phosphorus and silicon and preferably phosphorus and optionally at least one organic additive and a support comprising and preferably consisting of said alumina comprising lanthanum prepared according to any one of claims 1 to 9.

11. A process according to claim 10 wherein the temperature of the hydrotreating process is between 200 and 450°C, and preferably between 300 and 400°C, the pressure is between 0.5 and 30 MPa, and preferably between 5 and 20 MPa, the hourly volumetric velocity (defined as the ratio of the volumetric flow rate of feed to the volume of catalyst per hour) is between 0.1 and 20 h-1 and preferably between 0.2 and 5 h-1, and the hydrogen / feed ratio expressed as volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feed is between 50 1 / 1 and 2000 1 / 1.