Hydrocracking process with catalyst comprising a zeolite Y not globally dealuminized, an element of group VB, and a promoter element of boron, phosphorus and silicon

#The present invention relates to a catalyst for hydrocracking hydrocarbon feeds, the said catalyst comprising at least one amorphous or poorly crystallized matrix of the oxide type, at least one element (metal) of group VB (group 5 according to the new coding of the period classification of the elements: Handbook of Chemistry and Physics, 76th edition, 1995-1996, inside first cover page), preferably niobium, at least one zeolite Y not globally dealuminized, at least one promoter element chosen from the group consisting of boron, phosphorus and silicon, optionally at least one element (metal) chosen from group VIB and/or group VIII (group 6 and groups 8, 9 and 10 according to the new coding of the period classification of the elements), preferably molybdenum and tungsten, cobalt, nickel and iron. The catalyst also optionally comprises at least one element of group VIIA (halogen group, group 17 according to the new coding of the periodic classification of the elements), such as, for example, fluorine.

#The present invention also relates to processes for the preparation of the said catalyst, and to its use for hydrocracking hydrocarbon feeds, such as petroleum cuts, cuts produced from coal containing aromatic and/or olefinic and/or naphthenic and/or paraffinic compounds, the said feeds optionally comprising metals, and/or nitrogen, and/or oxygen, and/or sulphur.

#Hydrocracking of heavy petroleum cuts is a very important process in refining with which, starting from excess heavy feeds of low value, lighter fractions such as gasolines, jet fuels and light gas oils can be produced, which the refiner requires in order to adapt his production to the demand structure. Some hydrocracking processes also allow production of a highly purified residue which can constitute excellent bases for oils. In contrast to catalytic cracking, the advantage of catalytic hydrocracking is that middle distillates, jet fuels and gas oils of very good quality are provided. The gasoline produced has an octane index much lower than that produced from catalytic cracking.

#A hydrocracking catalyst support comprising a zeolite Y not globally dealuminized was produced in a large amount in order to be able to prepare various catalysts based on the same support. For this, 19.7% by weight of a non-dealuminized zeolite Y with a unit cell parameter equal to 2.453 nm and a global SiO2/Al2O3 ratio of 6.6 and a skeleton SiO2/Al2O3 ratio of 8.6 is used, and is mixed with 80.3% by weight of a matrix of ultrafine tabular boehmite or alumina gel marketed under the name SB3 by the company Condéa Chemie GmbH. This powder mixture was subsequently mixed with an aqueous solution comprising 66% nitric acid (7% by weight of acid per gram of dry gel) and then kneaded for 15 minutes. At the end of this kneading, the paste obtained is passed through a die with cylindrical orifices of a diameter equal to 1.4 mm. The extrudates are subsequently dried overnight at 120° C. and then calcined at 550° C. for 2 hours in damp air containing 7.5% by volume of water. The support Z3 is thus obtained in the form of cylindrical extrudates of 1.2 mm diameter having a specific surface area of 351 m2/g, a pore volume of 0.58 cm3/g and a monomodal pore size distribution centred on 10 mm. Analysis of the support by X-ray diffraction shows that it is composed of cubic gamma-alumina of low crystallinity and zeolite Y with a unit cell parameter of 2.444 nm and a global SiO2/Al2O3 ratio of 6.7 and a skeleton SiO2/Al2O3 ratio of 13.9.

#A hydrocracking catalyst support comprising a small amount of zeolite Y not globally dealuminized was produced in a large amount in the same manner in order to be able to prepare various catalysts based on the same support. For this, 8.6% by weight of the zeolite Y described above is used, and is mixed with 91.4% by weight of a matrix composed of ultrafine tabular boehmite or alumina gel marketed under the name SB3 by the company Condéa Chemie GmbH. This powder mixture was subsequently mixed with an aqueous solution comprising 66% nitric acid (7% by weight of acid per gram of dry gel) and then kneaded for 15 minutes. At the end of this kneading, the paste obtained is passed through a die having cylindrical orifices of a diameter equal to 1.4 mm. The extrudates are subsequently dried overnight at 120° C. and then calcined at 550° C. for 2 hours in damp air containing 7.5% by volume of water. The support Z5 is thus obtained in the form of cylindrical extrudates of 1.2 mm diameter having a specific surface area of 259 m2/g, a pore volume of 0.57 cm3/g and a monomodal pore size distribution centred on 10 mm. Analysis of the support by X-ray diffraction shows that it is composed of cubic gamma-alumina of low crystallinity and zeolite Y with a unit cell parameter of 2.444 nm and a global SiO2/Al2O3 ratio of 6.7 and a skeleton SiO2/Al2O3 ratio of 14.1.

#The extrudates of support Z3 of example 1 are impregnated in the dry state with an aqueous solution of a mixture of ammonium heptamolybdate and nickel nitrate, dried overnight at 120° C. in air and finally calcined in air at 550° C. The weight contents of the catalyst NiMo3 which are obtained are indicated in table 1. The catalyst NiMo3 contains, in particular, 16.6% by weight of zeolite Y. Analysis of the support by X-ray diffraction shows that it is composed of cubic gamma-alumina of low crystallinity and zeolite Y with a unit cell parameter of 2.444 nm and a global SiO2/Al2O3 ratio of 6.6 and a skeleton SiO2/Al2O3 ratio of 14.2.