Process for the preparation of a catalyst based on molybdenum for use in hydrotreatment or in hydrocracking

Abstract

The invention concerns a process for the preparation of a catalyst for carrying out hydrogenation reactions in hydrotreatment and hydrocracking processes. Said catalyst is prepared from at least one mononuclear precursor based on molybdenum (Mo), in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where [R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1)], and optionally from at least one promoter element from group VIII. Said precursors are deposited onto an oxide support which is suitable for the process in which it is used, said catalyst being dried at a temperature of less than 200° C. then advantageously being sulphurized before being deployed in said process.

Claims

1. A process for the preparation of a catalyst comprising at least one support, optionally at least one metal from group VIII of the periodic classification of the elements and at least molybdenum, said process comprising: introducing the molybdenum onto the support, in an organic solvent A, in the form of at least one mononuclear precursor compound based on Mo, in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where: R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 and where R′=C.sub.x′H.sub.y′where x′≧1 and (x′−1)≦y′≦(2x′+1); to obtain an impregnated support, drying the impregnated support under vacuum and at ambient temperature to obtain a dried impregnated support, and conducting ex situ sulphurization of the dried impregnated support in a H.sub.2S/H.sub.2 or H.sub.2S/N.sub.2 mixture containing at least 5% by volume of H.sub.2S in the mixture at a temperature between 300 and 400° C.

2. The process as claimed in claim 1, in which the catalyst contains a metal from group VIII which is selected from cobalt, iron and nickel.

3. The process as claimed in claim 2, in which the metal from group VIII is nickel.

4. The process as claimed in claim 1, in which the molybdenum precursor is a mononuclear precursor based on Mo, used in its monomeric or dimeric form, having the following formula:
Mo(═O).sub.n(═S).sub.n″(OR).sub.a(SR′).sub.b(L1).sub.c(L2).sub.d(L3).sub.e(L4).sub.f(L5).sub.g where R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR″).sub.3 or R=Si(R″).sub.3, where R″=C.sub.x′′H.sub.y′′ where [x″≧1 and (x″−1)≦y″≦(2x″+1)], where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1) or R′=Si(OR″′).sub.3 or R′=Si(R″′).sub.3 where R″′=C.sub.x″′Hy″′ where [x″′≧1 and (x″′−1)≦y″′≦(2x″′+1)], where 0≦n+n′≦2 and 0≦n≦2 and 0≦n′≦2, where, if n =n′=0, then (a≠0 or b≠0) and (a+b+c+d+e+f+g=6 and 0≦a≦6, 0≦b≦6, 0≦c≦6, 0≦d≦6, 0≦e≦6, 0≦f≦6, 0≦g≦6, or(a+b+c+d+e+f+g=5 and 0≦a≦5, 0≦b≦5, 0≦c≦5, 0≦d≦5, 0≦e≦5, 0≦f≦5, 0≦g≦5),or (a+b+c+d+e+f+g=4 and 0≦a≦4, 0≦b≦4, 0≦c≦4, 0≦d≦4, 0≦e≦4, 0≦f≦4, 0≦g≦4), where, if (n=1 and n′=0) or (n′=1 and n=0), then a+b+c+d+e+f+g=4 and 0≦a≦4, 0≦b≦4, 0≦c≦4, 0≦d≦4, 0≦e≦4, 0≦f≦4, 0≦g≦4) or (a+b+c+d+e+f+g=3 and 0≦a≦3, 0≦b≦3, 0≦c≦3, 0≦d≦3, 0≦e≦3 , 0≦f≦3, 0≦g≦3), where, if n+n′=2 and 0≦n≦2 and 0≦n′≦2, then (a+b+c+d+e+f+g=2 and 0≦a≦2, and 0≦b≦2, 0≦c≦2, 0≦d≦2, 0≦e≦2, 0≦f≦2, 0≦g≦2), with (L1), (L2), (L3), (L4) and (L5) being selected from the following ligands: THF, dimethyl ether, dimethylsulphide, P(CH.sub.3).sub.3, allyl, aryl, halogen, amine, acetate, acetylacetonate, halide, hydroxide and —SH.

5. The process as claimed in claim 4, in which the molybdenum precursor is selected from Mo(OEt).sub.5, Mo(OEt).sub.6, Mo(═O)(OEt).sub.4, Mo(═S)(OEt).sub.4, Mo(═S)(SEt).sub.4, Mo(═O).sub.2(OEt).sub.2, Mo(OC.sub.6H.sub.5).sub.6, Mo(SEt).sub.5, Mo(SEt).sub.6, Mo(OEt)(SEt).sub.4, Mo(OEt).sub.2(SEt).sub.3, Mo(OEt).sub.3(SEt).sub.2, Mo(OEt).sub.4(SEt), Mo(═O)(OEt).sub.3(acac) with Et=CH.sub.2CH.sub.3 (ethyl group) and acac=(CH.sub.3COCHCOCH.sub.3).sup.−(acetylacetonate) in their monomeric or dimeric form.

6. A process for the preparation of a catalyst as claimed in claim 1, in which the molybdenum and the optional metal or metals from group VIII are introduced simultaneously or successively.

7. A process for the preparation of a catalyst as claimed in claim 1, comprising at least the following steps: a) impregnation by bringing a solution S comprising the organic solvent A with at least said mononuclear precursor based on molybdenum, in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1), into contact with a porous mineral support, which has been calcined under vacuum or in a stream of inert gas to obtain an impregnated support; b) maturing the impregnated support in an anhydrous atmosphere; c) drying the impregnated support under vacuum and at ambient temperature to obtain a dried impregnated support; d) conducting ex situ sulphurization of the dried impregnated support in a H.sub.2S/H.sub.2 or H.sub.2S/N.sub.2 mixture containing at least 5% by volume of H.sub.2S in the mixture at a temperature between 300 and 400° C.

8. A process for the preparation of a catalyst as claimed in claim 7, in which the optional metal from group VIII is introduced into step a) in the same solution S as the molybdenum precursor or after the drying c) in a post-impregnation step a2) with the aid of a solution using an organic solvent B, or after the sulphurization step d) in a post-impregnation step a3) with the aid of an aqueous or organic solution.

9. A method comprising: preparing a catalyst comprising at least one support, optionally at least one metal from group VIII of the periodic classification of the elements, and at least molybdenum by said process as claimed in claim 1; and employing the catalyst in a reaction for the hydrogenation of hydrocarbon feeds.

10. A method as claimed in claim 9, wherein the hydrogenation is hydrotreatment or hydrocracking.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The invention concerns a process for the preparation of a catalyst for carrying out hydrogenation reactions in hydrotreatment and hydrocracking processes, prepared from at least one mononuclear precursor based on molybdenum, in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where [R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1)], and optionally at least one element from group VIII. Said precursors are deposited, using any method known to the skilled person, onto an oxide support suitable for the process in which it is used, said catalyst being dried at a temperature of less than 200° C. and advantageously being sulphurized before being deployed in said process.

(2) One of the advantages of the present invention thus resides in an innovative preparation of hydrotreatment catalysts based on molybdenum which allows for better dispersion by grafting and preservation of the precursors onto the support surface, even onto a silica support. These improvements mean that potentially, more active phase of the sulphide type can be generated, and thus potentially, more active sites can be generated for carrying out the desired hydrogenation or hydrocracking reactions and thus higher activities for the catalysts of the invention can be generated compared with those encountered in the literature, or activities can be generated which are identical to conventional catalysts but with half the number of metal atoms on the catalyst.

(3) Preferably, said preparation process comprises at least the following steps: a) a step for impregnation by bringing a solution comprising an organic solvent A and at least one mononuclear precursor based on Mo, in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where [R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 where R′ =C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1)], into contact with a porous mineral support, which has advantageously been calcined under low vacuum or high vacuum or in a stream of inert gas to evacuate the water which might be physisorbed on said support; b) a maturation step; c) a step for drying the impregnated support at a temperature of less than 200° C., in an anhydrous atmosphere or under low vacuum or high vacuum or in a stream of inert gas; d) a step for sulphurization, preferably carried out ex situ in a H.sub.2S/H.sub.2 or H.sub.2S/N.sub.2 mixture containing at least 5% by volume of H.sub.2S in the mixture at a temperature equal to or higher than ambient temperature.

(4) The optional element or elements from group VIII, hereinafter denoted the promoter(s), may be introduced in solution either: i) at the impregnation step a), co-impregnated with the mononuclear precursor based on molybdenum; ii) after the drying step c) in a step known as post-impregnation a2) with the aid of a solution using an organic solvent B. In this case, a second step for maturation b2) and a second drying step c2) at a temperature of less than 200° C. are necessary and may be carried out under the same conditions as the conditions described during steps b) and c); iii) after step d), in a post-impregnation step a3) with the aid of an aqueous solution or an organic solution. In this case, it is necessary to add a new maturation step b3), a new drying step c3) at a temperature of less than 200° C. and a new sulphurization step d2) before using the catalyst in the hydrotreatment or hydrocracking process in accordance with the invention.

(5) The mononuclear precursor based on Mo, used in its monomeric or dimeric form, in accordance with the invention advantageously has the formula:
Mo(═O).sub.n(═S).sub.n′(OR).sub.a(SR′).sub.b(L1).sub.c(L2).sub.d(L3).sub.e(L4).sub.f(L5).sub.g where R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR″).sub.3 or R=Si(R″).sub.3 where R″=C.sub.x′′H.sub.y′′ where [x″≧1 and (x″−1)≦y″≦(2x″-+1)], where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1) or R′=Si(OR′″).sub.3 or R′=Si(R′″).sub.3 where R′″=C.sub.x′″H.sub.y′″ where [x′″≧1 and (x′″−1)≦y′″≦(2x′″+)], where 0≦n+n′≦2 and 0≦n≦2 and 0≦n′≦2, where, if n=n′=0, then (a≠0 or b≠0) and [(a+b+c+d+e+f+g=6 and 0≦a≦6, 0≦b≦6, 0≦c≦6, 0≦d≦6, 0≦e≦6, 0≦f≦6, 0≦g≦6, or (a+b+c+d+e+f+g=5 and 0≦a≦5, 0≦b≦5, 0≦c≦5, 0≦d≦5, 0≦e≦5, 0≦f≦5, 0≦g≦5), or (a+b+c+d+e+f+g=4 and 0≦a≦4, 0≦b≦4, 0≦c≦4, 0≦d≦4, 0≦e≦4, 0≦f≦4, 0≦g≦4)], where, if [(n=1 and n′=0) or (n′=1 and n=0)], then [a+b+c+d+e+f+g=4 and 0≦a≦4, 0≦b≦4, 0≦c≦4, 0≦d≦4, 0≦e≦4, 0≦f≦4, 0≦g≦4)] or [(a+b+c+d+e+f+g=3 and 0≦a≦3, 0≦b≦3, 0≦c≦3, 0≦d≦3, 0≦e≦3, 0≦f≦3, 0≦g≦3)], where, if [n+n′=2 and 0≦n≦2 and 0≦n′≦2], then (a+b+c+d+e+f+g=2 and 0≦a≦2, 0≦b≦2, 0≦c≦2, 0≦d≦2, 0≦e≦2, 0≦f≦2, 0≦g≦2),
with (L1), (L2), (L3), (L4) and (L5) being ligands which are well known to the skilled person and of type THF, dimethyl ether, dimethylsulphide, P(CH.sub.3).sub.3, allyl, aryl, halogenated (selected from fluorinated, chlorinated and brominated), amine, acetate, acetylacetonate, halide, hydroxide, —SH, etc. Preferably, the ligands are selected from acetylacetonate, THF and dimethyl ether.

(6) Preferably, the precursors in accordance with the invention do not contain the ligand (L1), (L2), (L3), (L4) and (L5).

(7) Preferably, the precursors in accordance with the invention are selected from the following compounds: Mo(OEt).sub.5, Mo(OEt).sub.6, Mo(═O)(OEt).sub.4, Mo(═S)(OEt).sub.4, Mo(═S)(SEt).sub.4, Mo(═O).sub.2(OEt).sub.2, Mo(OC.sub.6H.sub.5).sub.6, Mo(SEt).sub.5, Mo(SEt).sub.6, Mo(OEt)(SEt).sub.4, Mo(OEt).sub.2(SEt).sub.3, Mo(OEt).sub.3(SEt).sub.2, Mo(OEt).sub.4(SEt), Mo(═O)(OEt).sub.3(acac) with Et=CH.sub.2CH.sub.3 (ethyl group) and acac=(CH.sub.3COCHCOCH.sub.3).sup.− (acetylacetonate), in their monomeric or dimeric form.

(8) Still more preferably, the precursor in accordance with the invention is Mo(OEt).sub.5.

(9) The quantity of molybdenum, Mo, is generally in the range 4% to 30% by weight with respect to the final catalyst, and preferably in the range 7% to 25% by weight with respect to the final catalyst, obtained after the last preparation step, before deploying it in the hydrotreatment process or the hydrocracking process.

(10) The surface density, which corresponds to the quantity of molybdenum atoms, Mo, deposited per unit surface area of the support, is advantageously in the range 0.5 to 8 atoms of Mo per square nanometre of support, preferably in the range 1 to 7 Mo atoms per square nanometre of support.

(11) Step a), for bringing the solution and the support into contact, is an impregnation. Impregnations are well known to the skilled person. The impregnation method of the invention is selected from dry impregnation, excess impregnation, and successive impregnations. The method termed dry impregnation is advantageously used.

(12) The organic solvent A used in step a) is generally an alkane, an alcohol, an ether, a ketone, a chlorinated solvent or an aromatic compound. Cyclohexane and n-hexane are preferably used.

(13) Step b) is a maturation step intended to allow the species to diffuse to the core of the support. It is advantageously carried out in an anhydrous atmosphere (without water), preferably for 30 minutes to 24 hours at ambient temperature. The atmosphere should preferably be anhydrous so as not to polycondense the pre-impregnated precursors.

(14) Drying carried out during step c) is intended to remove the impregnation solvent A. The atmosphere should preferably be anhydrous (no water) so that said pre-impregnated precursors are not polycondensed. The temperature must not exceed 200° C. in order to keep said precursors grafted or deposited on the surface of the support intact. Preferably, the temperature will not exceed 120° C. Highly preferably, drying is carried out under vacuum at ambient temperature. This step can alternatively be carried out by passing through an inert gas.

(15) Sulphurization step d) is advantageously carried out ex situ using a H.sub.2S/H.sub.2 or H.sub.2S/N.sub.2 gas mixture containing at least 5% by volume of H.sub.2S in the mixture at a temperature which is ambient temperature or higher, at a total pressure equal to or higher than 1 bar for at least 2 h. Preferably, the sulphurization temperature is 250° C. Highly preferably, the sulphurization temperature is 350° C.

(16) Sulphurization step d) may also, or in addition to step d) carried out ex situ, be carried out in situ at the start of carrying out the catalytic process using the catalyst, for example a hydrotreatment or hydrocracking process, using any sulphurization process which is well known to the skilled person, as described above.

(17) The preferred elements from group VIII are non-noble elements: they are selected from Ni, Co and Fe. Preferably, the elements from group VIII are cobalt and nickel. Highly preferably, the element from group VIII is nickel. The metal from group VIII is introduced in the form of salts, chelating compounds, alkoxides or glycoxides, and preferably in the form of acetylacetonate or acetate.

(18) If the promoter is introduced as described in the invention in i) and ii), the compounds containing the element from group VIII are preferably sulphur-containing compounds, oxygen-containing compounds, chelating compounds, alkoxides and glycoxides. Preferably, it is introduced in the form of acetylacetonate or acetate.

(19) If the promoter is introduced as described in the invention at iii), the compounds containing the element from group VIII may be introduced in the form of salts, sulphur-containing compounds, oxygen-containing compounds, chelating compounds, alkoxides and glycoxides. Preferably, it is introduced in the form of acetylacetonate or acetate.

(20) The sources of elements from group VIII which may advantageously be used in the form of salts are well known to the skilled person. They are selected from nitrates, sulphates, hydroxides, phosphates and halides selected from chlorides, bromides and fluorides.

(21) The promoter elements from group VIII are advantageously present in the catalyst in quantities in the range 0.1% to 8% by weight, preferably in the range 0.5% to 5% by weight with respect to the final catalyst obtained after the last preparation step, before using it in the hydrotreatment process or the hydrocracking process.

(22) The organic solvent B used when the promoter is introduced after step c) in a step termed post-impregnation is generally an alkane, an alcohol, an ether, a ketone, a chlorinated compound or an aromatic compound. Toluene, benzene, dichloromethane, tetrahydrofuran, cyclohexane, n-hexane, ethanol, methanol and acetone are preferably used.

(23) The solvent used for impregnation of the promoter (element from group VIII) in the case of step iii) corresponds either to the organic solvent B in the case in which non-saline precursors and water are used, or an alcohol when the precursors are saline.

(24) The hydrodehydrogenating function of said catalytic precursor is ensured by molybdenum and optionally by at least one element from group VIII. Advantageously, the hydrodehydrogenating function is selected from the group formed by combinations of the elements: nickel-molybdenum or cobalt-molybdenum or nickel-cobalt-molybdenum.
The support for the catalyst of the invention is a porous mineral support which advantageously comprises at least aluminium and/or at least silicon.

(25) Preferably, said support comprises at least one aluminium oxide or at least one silicon oxide. Advantageously, said support may or may not be acidic. Advantageously, said support may or may not be mesostructured.

(26) Said porous mineral support may advantageously be selected from transition aluminas, doped aluminas, preferably with phosphorus, boron and/or fluorine, silicalite and silicas, aluminosilicates, preferably amorphous or of low crystallinity, crystallized non-zeolitic molecular sieves such as silicoaluminophosphates, aluminophosphates, ferrosilicates, titanium silicoaluminates, borosilicates, chromosilicates and transition metal aluminophosphates, alone or as a mixture.

(27) In the case in which said porous mineral support is selected from transition aluminas, silicalite and silicas such as mesoporous silicas, for example, said support is not acidic. The term “transition alumina” means, for example, an alpha phase alumina, a delta phase alumina, a gamma phase alumina or a mixture of aluminas from these various phases.

(28) In the case in which said porous mineral support is selected from aluminosilicates, preferably amorphous or of low crystallinity, non-zeolitic crystalline molecular sieves such as silicoaluminophosphates, aluminophosphates, ferrosilicates, titanium silicoaluminates, borosilicates, chromosilicates and transition metal aluminophosphates, doped aluminas, preferably with phosphorus, boron and/or fluorine, said support is acidic. Any known silica-alumina or any aluminosilicate known to the skilled person is suitable in the context of the invention.

(29) When said porous mineral support is said to be mesostructured, it then comprises elementary particles organized on the mesopore scale of the material of the invention, i.e. an organized porosity on the scale of pores with a uniform diameter in the range 1.5 to 50 nm, preferably in the range 1.5 to 30 nm and still more preferably in the range 4 to 20 nm and distributed in a homogeneous and regular manner in each of said particles (mesostructuring). The material located between the mesopores of the elementary mesostructured particle is amorphous and forms walls or partitions the thickness of which is in the range 1 to 30 nm, preferably in the range 1 to 10 nm. The thickness of the walls corresponds to the distance separating a first mesopore from a second mesopore, the second mesopore being the pore closest to said first mesopore. The organization of the mesoporosity described above leads to a structure of said constituent particle of said support, which may be hexagonal, vermicular or cubic, preferably hexagonal. Preferably, said mesostructured porous mineral support is selected from silica and silica-alumina.

(30) In addition to at least one of the oxide compounds cited above, the porous mineral support of the invention, whether or not it is acidic, mesostructured or not mesostructured, may also advantageously comprise at least one zeolite and in particular but not restricted to those listed in the “Atlas of Zeolite Framework types”, 6.sup.th revised edition, 2007, Ch. Baerlocher, L. B. L. McCusker, D. H. Olson”. The zeolitic crystals may be selected from the zeolites IZM-2, ZSM-5, ZSM-12, ZSM-48, ZSM-22, ZSM-23, ZBM-30, EU-2, EU-11, Silicalite, Beta, zeolite A, Faujasite, Y, USY, VUSY, SDUSY, Mordenite, NU-10, NU-87, NU-88, NU-86, NU-85, IM-5, IM-12, IM-16, Ferrierite and EU-1. Highly preferably, the zeolitic crystals may be selected from zeolites with structure type MFI, BEA, FAU, and LTA. Different zeolitic crystals and in particular zeolites with a different structure type may be present in the porous mineral support constituting the material in accordance with the invention. In particular, the porous mineral support in accordance with the invention may advantageously comprise at least first zeolitic crystals the zeolite of which is selected from the zeolites IZM-2, ZSM-5, ZSM-12, ZSM-48, ZSM-22, ZSM-23, ZBM-30, EU-2, EU-11, Silicalite, Beta, zeolite A, Faujasite, Y, USY, VUSY, SDUSY, Mordenite, NU-10, NU-87, NU-88, NU-86, NU-85, IM-5, IM-12, IM-16, Ferrierite and EU-1, preferably from zeolites with structure type MFI, BEA, FAU, and LTA and at least second zeolitic crystals the zeolite of which is different from the first zeolitic crystals and is selected from the zeolites IZM-2, ZSM-5, ZSM-12, ZSM-48, ZSM-22, ZSM-23, ZBM-30, EU-2, EU-11, Silicalite, Beta, zeolite A, Faujasite, Y, USY, VUSY, SDUSY, Mordenite, NU-10, NU-87, NU-88, NU-86, NU-85, IM-5, IM-12, IM-16, Ferrierite and EU-1, preferably from zeolites with structure type MFI, BEA, FAU, and LTA. The zeolitic crystals advantageously comprise at least one zeolite which is either entirely silicic or, in addition to silicon, contains at least one element T selected from aluminium, iron, boron, indium, gallium and germanium, preferably aluminium.

(31) In addition to at least one of the oxide compounds cited above, the porous mineral support may also advantageously comprise at least one simple synthetic or natural clay of the dioctahedral 2:1 phyllosilicate or trioctahedral 3:1 phyllosilicate type such as kaolinite, antigorite, chrysotile, montmorillonnite, beidellite, vermiculite, talc, hectorite, saponite or laponite. These clays may also optionally have been delaminated.

(32) Preferably, said porous mineral support is selected from mesoporous alumina and silica-alumina used alone or as a mixture, or mesostructured silicas and silica-aluminas, used alone or as a mixture.

(33) The catalyst may be used in any of the forms known to the skilled person: it may be in the form of a powder, in the form of beads or in the form of cylindrical, trilobal or quadrilobal extrudates. Different shapes may be mixed.

(34) In accordance with the invention, said catalyst is advantageously partially sulphurized by means of at least one step for sulphurization in the gas phase described in step d) of the preparation process, before being used in the hydrotreatment or hydrocracking process of the invention. This sulphurization step described in step d) generates the active sulphide phase in a partial manner, but it can be used to prevent leaching of the metallic precursors in contact with the hydrocarbon feed to be treated or possibly in contact with the sulphurization feed. The catalyst obtained is used in a hydrotreatment or hydrocracking unit where it can undergo in situ sulphurization carried out with the aid of the feed to be treated in the presence of hydrogen and hydrogen sulphide (H.sub.2S) introduced as is or obtained from the decomposition of an organic sulphur-containing compound selected from dimethyldisulphide (DMDS), dimethylsulphide, n-butylmercaptan and polysulphide compounds. This sulphurization is carried out at a temperature in the range 200° C. to 600° C., preferably in the range 300° C. to 400° C., using processes which are well known to the skilled person.

(35) The Hydrotreatment and Hydrocracking Processes, as Well as Feeds

(36) Finally, the invention also concerns the use of the catalyst of the invention in processes for the hydrotreatment and hydrocracking of oil cuts.

(37) The catalyst prepared with the process of the invention may advantageously be used in any process known to the skilled person necessitating hydrogenation reactions of hydrocarbon cuts and preferably of catalytically cracked gasoline cuts. The hydrotreatment and hydrocracking processes of the invention may advantageously be carried out in any type of reactor operated in fixed bed or moving bed or ebullated bed mode. Preferably, said hydrotreatment process or said hydrocracking process is carried out in a reactor operated in fixed bed mode.

(38) The catalysts obtained by the preparation process of the invention are advantageously used for reactions for the hydrotreatment of hydrocarbon feeds such as oil cuts, cuts obtained from coal or hydrocarbons produced from natural gas, more particularly necessitating hydrogenation reactions: the hydrogenation of aromatics, hydrodenitrogenation, hydrodesulphurization, hydrodemetallization or hydrocracking of hydrocarbon feeds are reactions which may be cited.

(39) These catalysts may also advantageously be used during pre-treatment of catalytically cracked feeds or feeds for the hydrodesulphurization of residues or for the intense hydrodesulphurization of gas oils (ULSD or Ultra Low Sulphur Diesel).

(40) Examples of feeds employed in the hydrotreatment processes are gasolines, gas oils, vacuum gas oils, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuels, oils, waxes and paraffins, spent oils, residues or deasphalted crudes, or feeds deriving from thermal or catalytic conversion processes, used alone or as mixtures. The feeds which are treated, in particular those cited above, generally contain heteroatoms such as sulphur, oxygen and nitrogen and, for the heavy feeds, they usually also contain metals.

(41) The operating conditions used in the processes using the reactions for the hydrotreatment of hydrocarbon feeds described above are generally as follows: the temperature is advantageously in the range 180° C. to 450° C., preferably in the range 250° C. to 440° C., the pressure is advantageously in the range 0.5 to 30 MPa, preferably in the range 1 to 18 MPa, the hourly space velocity is advantageously in the range 0.1 to 20 h.sup.−1, preferably in the range 0.2 to 5 h.sup.−1, and the hydrogen/feed ratio, expressed as the volume of hydrogen measured under normal temperature and pressure conditions per volume of liquid feed, is advantageously in the range 50 L/L to 2000 L/L.

(42) Examples of the feeds employed in the hydrocracking reactions are LCO (light cycle oil (light gas oils obtained from a catalytic cracking unit)), atmospheric distillates, vacuum distillates, for example gas oils obtained from straight run distillation of crude or conversion units such as FCC, coking or visbreaking units, feeds deriving from aromatics extraction units, lubricating base oils or bases obtained from solvent dewaxing of lubricating base oils, distillates deriving from fixed bed or ebullated bed desulphurization or hydroconversion processes, atmospheric residues and/or vacuum residues and/or deasphalted oils, or the feed may be a deasphalted oil or comprise vegetable oils, or indeed derive from the conversion of feeds obtained from biomass. Said hydrocarbon feed treated in the hydrocracking process of the invention may also be a mixture of said feeds as cited above. The hydrocarbon feeds present in said feed are aromatic compounds, olefinic compounds, naphthenic compounds and/or paraffinic compounds.

(43) Said hydrocarbon feed advantageously comprises heteroatoms. Preferably, said heteroatoms are selected from nitrogen, sulphur and a mixture of these two elements. When nitrogen is present in said feed to be treated, the nitrogen content is 500 ppm or more, and preferably it is in the range 500 to 10000 ppm by weight, more preferably in the range 700 to 4000 ppm by weight and still more preferably in the range 1000 to 4000 ppm. When sulphur is present in said feed to be treated, the sulphur content is in the range 0.01% to 5% by weight, preferably in the range 0.2% to 4% by weight and still more preferably in the range 0.5% to 3% by weight.

(44) Said hydrocarbon feed may optionally advantageously contain metals, in particular nickel and vanadium. The cumulative nickel and vanadium content of said hydrocarbon feed treated using the hydrocracking process of the invention is preferably less than 1 ppm by weight. The asphaltenes content of said hydrocarbon feed is generally less than 3000 ppm, preferably less than 1000 ppm, still more preferably less than 200 ppm.

(45) The hydrocracking process of the invention covers the fields of pressure and conversion from mild hydrocracking to high pressure hydrocracking. The term “mild hydrocracking” means hydrocracking leading to moderate conversions, generally less than 40%, and operating at low pressure, generally between 2 MPa and 10 MPa. The hydrocracking process of the invention is carried out in the presence of at least one hydrotreatment catalyst or hydrocracking catalyst in accordance with the invention. The hydrocracking process of the invention may be carried out in one or two steps, independently of the pressure at which said process is carried out. It is carried out in the presence of one or more catalyst(s) obtained using the preparation process described above, in one or more reaction unit(s) equipped with one or more reactors(s).

(46) The operating conditions used in the hydrocracking processes of the invention may vary widely as a function of the nature of the feed, the quality of the desired products and the facilities available to the refiner. In accordance with the hydrocracking process of the invention, said hydrocracking catalyst is advantageously brought into contact, in the presence of hydrogen, with said hydrocarbon feed at a temperature of more than 200° C., often in the range 250° C. to 480° C., advantageously in the range 320° C. to 450° C., preferably in the range 330° C. to 435° C., at a pressure of more than 1 MPa, often in the range 2 to 25 MPa, preferably in the range 3 to 20 MPa, the space velocity (volume flow rate of feed divided by the volume of catalyst) being in the range 0.1 to 20 h.sup.−1, preferably in the range 0.1 to 6 h.sup.−1, still more preferably in the range 0.2 to 3 h.sup.−1, and the quantity of hydrogen introduced is such that the volume ratio of litres of hydrogen/litres of hydrocarbon is in the range 80 to 5000 L/L, often in the range 100 to 2000 L/L.

(47) These operating conditions used in the hydrocracking process of the invention can generally be used to reach conversions per pass into products with boiling points of at most 370° C. and advantageously at most 340° C., of more than 15%, still more preferably in the range 20% to 95%.

EXAMPLES

(48) The examples below are presented by way of illustration; they demonstrate the large increase in activity of catalysts prepared in accordance with the process of the invention compared with prior art catalysts, and specify the invention without in any way limiting its scope.

Example 1

NiMo Catalyst Supported on Alumina, with a Surface Density of 3 Mo/Nm2 and Ni/Mo=0.3 (at/at) (in Accordance with the Invention)

(49) The molybdenum was dry impregnated in a strictly non-aqueous medium onto a commercial γ alumina type support synthesized by calcining a gel of aluminium salts (287 m.sup.2/g). The support was initially calcined at 300° C. in air for 6 hours at atmospheric pressure. It was then heated to 300° C. for 14 hours under high vacuum (10.sup.−5 mbar) before being stored in an inert medium, in a glove box. The molybdenum precursor was molybdenum pentaethoxide, Mo(OC.sub.2H.sub.5).sub.5. Dry degassed cyclohexane was used as the solvent. 1.96 mL of impregnation solution, prepared from 1.18 g of precursor, was impregnated onto 2.58 g of dry support. The quantity of molybdenum was adjusted so as to obtain 3 Mo/nm.sup.2. After maturing for 15 hours, the extrudates were dried under vacuum (10.sup.−5 mbar) for 2 hours at ambient temperature. This non-sulphurized catalyst was defined by the usual notation Mo/Al.sub.2O.sub.3.

(50) A solution of nickel bis-acetylacetonate Ni(acac).sub.2 was then impregnated onto this catalyst. Dry degassed toluene was used as the solvent. The nickel precursor was first dissolved in hot toluene, then 2.45 mL of a solution containing 0.41 g of precursor was impregnated onto approximately 3.76 g of Mo/Al.sub.2O.sub.3. After maturing for 15 hours, the extrudates were dried under vacuum (10.sup.−5 mbar) for 3 hours at ambient temperature. For this non-sulphurized NiMo/Al.sub.2O.sub.3 catalyst, the molybdenum and nickel contents were respectively 11.60% by weight and 2.21% by weight, which corresponded to an actual surface density of 3.0 Mo/nm.sup.2 and a Ni/Mo atomic ratio of 0.30. This catalyst C1 was in accordance with the invention.

Example 2

NiMo Catalyst Supported on Alumina, with a Surface Density of 3 Mo/Nm2 and Ni/Mo=0.3 (at/at) (not in Accordance with the Invention)

(51) The molybdenum and nickel were dry co-impregnated in an aqueous medium onto a commercial γ alumina type support synthesised by calcining a gel of aluminium salts (289 m.sup.2/g). The molybdenum precursor was ammonium heptamolybdate (NH.sub.4).sub.6Mo.sub.7O.sub.24.×H.sub.2O. The nickel precursor was nickel nitrate Ni(NO.sub.3).sub.2.×H.sub.2O. The quantities of precursors were adjusted so as to obtain 3 Mo/nm.sup.2 and Ni/Mo=0.30 (at/at). After maturing for 15 hours, the extrudates were dried at 120° C. for 15 hours. They were then calcined at 450° C. in a stream of air for 2 hours. The molybdenum and nickel contents of this non-sulphurized NiMo/Al.sub.2O.sub.3 catalyst were respectively 11.75% by weight and 2.12% by weight, which corresponded to an actual surface density of 3.0 Mo/nm.sup.2 and a Ni/Mo atomic ratio of 0.29. This catalyst H1 was not in accordance with the invention.

Example 3

Test for the Hydrogenation of Toluene (Aromatic Model Molecule) in the Presence of Aniline

(52) The test for the hydrogenation of toluene in the presence of aniline is intended to evaluate the hydrogenating activity of supported or bulk sulphurized catalysts in the presence of H.sub.2S and under hydrogen pressure. The isomerization which characterizes the acid function of the catalyst is inhibited by the presence of aniline, at low temperatures and/or by the presence of NH.sub.3 (obtained from the decomposition of aniline) at higher temperatures. The aniline and/or NH.sub.3 will react with the acidic sites of the support by an acid-base reaction. The characteristic isomerization reactions of the acidity of the support then do not exist.

(53) We were careful to carry out the comparison of the catalysts on the same catalytic test unit in order not to falsify the comparisons by using different catalytic test tools which could produce out-of-line results.

(54) The catalytic test was carried out in the gas phase in a fixed bed traversed reactor. The test can be broken down into two distinct phases, sulphurization and the catalytic test. The test was carried out at 60 bar.

(55) The catalysts were initially sulphurized ex situ in the gas phase ((H.sub.2S/H.sub.2 mixture) in which the quantity of H.sub.2S was 15% by volume) at a temperature of 350° C. for 2 h.

(56) Activation Phase:

(57) The catalysts were subjected to a rise in temperature under test feed in a fixed bed traversed tube reactor of a Flowrence type pilot unit (from Avantium), the fluids moving from top to bottom. The measurements of the hydrogenating activity were carried out immediately after reaching the test temperature.

(58) Catalytic Test:

(59) The test feed was composed of dimethyldisulphide (DMDS), toluene, cyclohexane and aniline.

(60) The stabilized catalytic activities of equal volumes of catalysts (450 μL) were measured at a temperature of 350° C.

(61) The operating conditions of the test were as follows (assuming total vaporization and the perfect gas law): For Ptot=60 bar and T=350° C.: PpH.sub.2=36.62 bar PpNH.sub.3=0.09 bar PpH.sub.2S=2.16 bar Pptoluene=3.75 bar Ppcyclohexane=15.22 bar HSV=4 L/L/h during the activation phase, and HSV=2 L/L/h and H.sub.2/feed=450 L/L during the test phase.

(62) Effluent samples were analysed by gas chromatography. The catalytic performances of the catalysts are expressed using the corresponding hydrogenating activity, using first order kinetics:

(63) ${\mathrm{AH}}_{1.\mathrm{order}}=\ln \frac{100}{\left(100-\%{\mathrm{HYD}}_{\mathrm{toluene}}\right)}$

(64) %HYD.sub.toluene corresponds to the percentage of hydrogenated toluene.

(65) The catalytic performances are shown in Table 1.

(66) TABLE-US-00001 TABLE 1 Relative hydrogenating activity of catalysts C1 and H1. These were expressed as the relative activity, assuming that of catalyst H1 was equal to 100. Hydrogenating activity Catalyst relative to H1 C1 (in accordance with the invention) 145 H1 (not in accordance with the invention) 100

(67) Table 1 shows the large gain in hydrogenating power obtained for the catalyst claimed in accordance with the invention prepared on alumina (C1). Catalyst C1, prepared from the molybdenum precursor Mo(OEt).sub.5 in accordance with the invention, is more active in hydrogenation than the catalyst which is homologous in formulation but prepared by a conventional pathway using a heteropolyanion salt (H1).

(68) The entire disclosures of all applications, patents and publications, cited herein and of corresponding French Application No. 13/53940, filed Apr. 30, 2013 are incorporated by reference herein.