Title of Invention	A PROCESS FOR HYDROTREATING A HYDROCARBON FEEDS IN AN EBULLATING BED REACTOR
Abstract	This invention relates to a process for hydrotreating an hydrocarbon feed in an ebuUating bed, using a catalyst comprising an extruded essentially alumina-based support, constituted by a plurality of juxtaposed agglomerates and partially in the form of packs of flakes and partially in the form of needles, and optionally comprising at least one catalytic metal or a compound of a catalytic metal from group VIB, and/or optionally at least one catalytic metal or compound of a catalytic metal from group VIII.

Title of Invention

A PROCESS FOR HYDROTREATING A HYDROCARBON FEEDS IN AN EBULLATING BED REACTOR

Abstract

This invention relates to a process for hydrotreating an hydrocarbon feed in an ebuUating bed, using a catalyst comprising an extruded essentially alumina-based support, constituted by a plurality of juxtaposed agglomerates and partially in the form of packs of flakes and partially in the form of needles, and optionally comprising at least one catalytic metal or a compound of a catalytic metal from group VIB, and/or optionally at least one catalytic metal or compound of a catalytic metal from group VIII.

Full Text	The present invention relates to the use of a catalyst for hydrorefining and/or hydroconverting hydrocarbon feeds (also known as hydrotreatment) in an ebullating bed reactor, the catalyst comprising an essentially alumina-based support in the form of extrudates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt. The present invention thus particularly relates to the use of the catalyst in a process for hydrorefining and/or hydroconverting hydrocarbon feeds such as petroleum cuts, cuts originating from coal, or hydrocarbons produced from natural gas. The hydrorefining and/or hydroconversion process of the invention comprises at least one three-phase reactor containing the hydrorefining and/or hydroconversion catalyst in an ebullating bed. This type of operation has been described, for example, in United States patents US-A-4 251295 or US-A-4 495 060 which describe the H-OIL process. Hydrotreatment of hydrocarbon feeds, such as sulphur-containing petroleum cuts, is becoming more and more important in refining with the increasing need to reduce the quantity of sulphur in petroleum cuts and to convert heavy fractions into lighter fractions which can be upgraded as a fuel. Both to satisfy the specifications imposed in every country for commercial fuels and for economical reasons, imported crudes which are becoming richer and richer in heavy fractions and in heteroatoms and more and more depleted in hydrogen must be upgraded to the best possible extent. This upgrading implies a relatively large reduction in the average molecular weight of heavy constituents, which can be obtained, for example, by cracking or hydrocracking the pre-refined feeds, i.e., desulphurized and denitrogenated feeds. Van Kessel et al explained this subject in detail in an article published in the review "Oil & Gas Journal", 16'February 1987, pages 55 to 66. The skilled person is aware that during hydrotreatment of petroleum fractions containing organometallic complexes, the majority of those complexes are destroyed in the presence of hydrogen, hydrogen sulphide, and a hydrotreatment catalyst. The constituent metal of such complexes then precipitates out in the form of a solid sulphide which then becomes fixed on the internal surface of the pores. This is particularly the case for vanadium, nickel, iron, sodium, titanium, silicon, and copper complexes which are naturally present to a greater or lesser extent in crude oils depending on the origin of the crude and which, during distillation, tend to concentrate in the high boiling point fractions and in particular in the residues. This is also the case for liquefied coal products which also comprise metals, in particular iron and titanium. The general term hydrodemetallization (HDM) is used to designate those organometallic complex destruction reactions in hydrocarbons. The accumulation of solid deposits in the catalyst pores can continue until a portion of the pores controlling access of reactants to a fraction of the interconnected pore network is completely blocked so that that fraction becomes inactive even if the pores of that fraction are only slightly blocked or even intact. That phenomenon can cause premature and very severe catalyst deactivation. It is particularly sensitive in hydrodemetallization reactions carried out in the presence of a supported heterogeneous catalyst. The term "heterogeneous" means not soluble in the hydrocarbon feed. In that case, it has been shown that pores at the grain periphery are blocked more quickly than central pores. Similarly, the pore mouths block up more quickly than their other portions. Pore blocking is accompanied by a gradual reduction in their diameter which increasingly limits molecule diffusion and increases the concentration gradient, thus accentuating the heterogeneity of the deposit from the periphery to the interior of the porous particles to the point that the pores opening to the outside are very rapidly blocked: access to the practically intact internal pores of the particles is thus denied to the reactants and the catalyst is prematurely deactivated. The phenomenon described above is known as pore mouth plugging. Proof of its existence and an analysis of its causes have been published a number of times' in the international scientific literature, for example: "Catalyst deactivation through pore mouth plugging" presented at the 5 International Chemical Engineering Symposium at Houston, Texas, U. S. A., March 1978, or "Effects of feed metals on catalyst ageing in hydroprocessing residuum" in Industrial Engineering Chemistry Process Design and Development, volume 20, pages 262 to 273 published in 1981 by the American Chemical Society, or more recently in "Effect of catalyst pore structure on hydrotreating of heavy oil" presented at the National conference of the American Chemical Society at Las Vegas, U. S. A., 30 March 1982. A catalyst for hydrotreatment of heavy hydrocarbon cuts containing metals must thus be composed of a catalytic support with a porosity profile which is particularly suitable for the specific diffusional constraints of hydrotreatment, in particular hydrodemetallization. The catalysts usually used for hydrotreatment processes are composed of a support on which metal oxides such as cobalt, nickel or molybdenum oxides are deposited. The catalyst is then sulphurated to transformed all or part of the metal oxides into metal sulphide phases. The support is generally alumina-based, its role consisting of dispersing the active phase and providing a texture which can capture metal impurities, while avoiding the blocking problems mentioned above. Catalysts with a particular pore distribution have been described in United States patent US-A-4 395 329. There are two types of prior art alumina-based supports. Firstly, alumina extrudates exist that are prepared from an alumina gel. Hydrotreatment catalysts prepared from such extrudates have a number of disadvantages. Firstly, the process for preparing the alumina gel is particularly polluting, in contrast to that of alumina originating from rapid dehydration of hydrargillite, known as flash alumina. The pores of alumina gel based supports are particularly suitable for hydrodesulphuration and hydrotreatment of light hydrocarbons, and not for other types of hydrotreatment. Further, even though such extrudates are balanced in their hydrodemetallization/hydrodesulphuration ratio, their hydrometallization retention capacity is low, in general at most 30% by weight, so they are rapidly saturated and have to be replaced. Further, considering the high production cost of the alumina gel, the manufacture of such catalysts is very expensive. Secondly, alumina beads prepared by rapid dehydration of hydrargillite then agglomerating the flash alumina powder obtained are used as a support for catalysts for hydrotreating hydrocarbon feeds containing metals. The cost of preparing these beads is lower, however in order to maintain it at a satisfactory level, beads with a diameter of more than 2 mm have to be prepared. As a result, the metals cannot be introduced right into the core of the beads, and the catalytic phase located there is not used. Hydrotreatment catalysts prepared from flash alumina extrudates which are smaller and which have a porosity which is suitable for hydrotreatment would not have all of those disadvantages, but there is currently no industrial process for preparing such catalysts. The present invention concerns the use of a catalyst for hydrotreating carbon-containing fractions in hydrotreatment reactions, in particular hydrogenation, hydrodenitrogenation, hydrodeoxygenation, hydrodearomatization, hydroisomerisation, hydrodealkylation, hydrodewaxing, hydrocracking, and hydrodesulphuration with a hydrodemetallization activity which is at least equivalent to that of catalysts currently known to the skilled person, to obtain particularly good hydrotreatment results with respect to prior art products. The catalyst of the invention comprises an essentially alumina-based support in the form of extrudates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt, more preferably nickel. The extruded support used in the catalyst of the invention is generally and preferably essentially based on alumina agglomerates, the alumina agglomerates generally and preferably being obtained by forming a starting alumina originating from rapid dehydration of hydrargilite, and generally having a total pore volume of at least 0.6 cm3g, an average mesoporous diameter in the range 15 to 36 nm (nanometers), and generally a quantity of alumina originating from boehmite decomposition in the range 5% to 70% by weight. The term "alumina originating from boehmite decomposition" means that during the extrudate preparation process, boehmite type alumina is produced to the point of representing 5% to 70% by weight of the total alumina, then decomposed. This quantity of alumina from boehmite decomposition is measured by X ray diffraction of the alumina before decomposing the boehmite. The extruded support of the catalyst of the invention can also be obtained by extruding a mixture of varying proportions of an alumina powder from rapid dehydration of hydrargillite (flash alumina) and at least one alumina gel obtained. for example, by precipitating aluminium salts such as aluminium chloride, aluminium sulphate, aluminium nitrate, or aluminium acetate, or by hydrolysis of aluminium alkoxides such as aluminium triethoxide. Such mixtures of flash alumina and alumina gel contain less than 50% by weight of alumina gel, preferably 1% to 45% of alumina gel. The catalyst used in the process of the invention can be prepared using any method which is known to the skilled person, more particularly using the methods described below. The support is formed by alumina extrudates with a diameter generally in the range 0.3 to 1.8 mm, preferably 0.8 to 1.8 mm, when the catalyst is used in an ebullating bed, the extrudates having the characteristics described above. Any known method can be used for the optional introduction of the catalytic metals, at any stage of the preparation, preferably by impregnation or co-mixing, onto the extrudates or prior to their forming by extrusion, the optional catalytic metals being at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt, more preferably nickel. The metals can optionaDy be mixed with the support by co-mixing at any step of the support preparation process. When there are a plurality, at least part of the group VIB and VIII metals can optionally be introduced separately or simultaneously during impregnation or co-mixing with the support, at any stage of forming or preparation. As an example, the catalyst of the invention can be prepared using a preparation process comprising the following steps: with at least one compound of a catalytic metal from group VIB and/or at least one compound of a catalytic metal from group VIII, optionally followed by ageing, and/or drying, then optional calcining; b) forming by extruding the product obtained from step a). The metals cited above are usually introduced into the catalyst in the form of precursors such as oxides, acids, salts, or organic complexes. The sum S of the group VIB and VIII metals, expressed as the oxides introduced into the catalysts, is in the range 0 to 50% by weight, preferably 0.5% to 50% by weight, more preferably 0.5% to 40% by weight. It is thus possible to use the support as a catalyst without introducing a catalytic metal into the catalyst. The preparation then generally comprises ageing and drying, then generally a heat treatment, for example calcining, at a temperature in the range 400°C to 800°C. The support the use of which is one of the essentially elements of the invention is essentially alumina-based. The support used in the catalyst of the invention is generally and preferably obtained by forming a starting alumina originating from rapid dehydration of hydrargillite, forming preferably being carried out using one of the processes described below. Processes for preparing the support of the invention are described below for a support constituted by alumina. When the support contains one or more other compounds, the compound or compounds or a precursor of the compound or compounds may be introduced at any stage in the process for preparing the support of the invention. It is also possible to introduce the compound or compounds by impregnating the formed alumina using the compound or compounds or any precursor of the compound or compounds. A first process for forming a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps: a, starting with an alumina originating from rapid dehydration of hydrargillite; b] rehydrating the starting alumina; Ci mixing the rehydrated alumina in the presence of an emulsion of at least one hydrocarbon in water; di extruding the alumina-based paste obtained from step Cj; ei drying and calcining the extrudates; fi carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates from step ei; gi drying and calcining the extrudates from step fj. A second process for forming the alumina from a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps: a2 starting from an alumina originating from rapid dehydration of hydrargillite; ba forming the alumina into beads in the presence of a pore-forming agent; C2 ageing the alumina beads obtained; d2 mixing the beads from step C2 to obtain a paste which is extruded; 62 drying and calcining the extrudates obtained; f2 carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates obtained from step 62; g2 drying and calcining the extrudates from step f2. A third process for forming an alumina from a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps: a3 starting from an alumina originating from rapid dehydration of hydrargillite; b3 rehydrating the starting alumina; C3 mixing the rehydrated alumina with a pseudo-boehmite gel, the gel being present in an amount in the range 1% to 30% by weight with respect to the rehydrated alumina and the gel; d3 extruding the alumina-based paste obtained from step 03; e3 drying and calcining the extrudates obtained; f3 carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates obtained from step e3; g3 optionally drying then calcining the extrudates from step f3. This process uses identical steps to steps ai, bi, di, ei, fi and gi of the first process described above. The alumina extrudates of the invention generally and preferably have a total pore volume (TPV) of at least 0.6 cm /g, preferably at least 0.65 cm /g. The TPV is measured as follows: the grain density and absolute density are determined: the grain densities (Dg) and absolute densities (Da) are measured using a mercury and helium picnometry method respectively, then the TPV is given by the formula: The average mesoporous diameter of the extrudates of the invention is also generally and preferably in the range 15 to 36 nm (manometers). The average mesoporous diameter for the given extrudates is measured using a graph of the pore distribution of said extrudates. It is the diameter for which the associated over 100 nm (macropores), or the macroporous volume; Venm represents the volume created by pores with a diameter of over 6 nm; Venm - Viooam represents the mesoporous volume, i.e., the volume created by pores with a diameter in the range 6 nm and 100 nm, i.e., the volume created by all the pores with a size in the range 6 nm to 100 nm (mesopores). These volumes are measured using the mercury penetration technique in which the Kelvin law is applied which defines a relationship between the pressure, the diameter of the smallest pore into which the diameter penetrates at that pressure, the wetting angle and the surface tension in the following formula: 0 = (4tcose).lO/P where 0 represents the pore diameter (in nm); t represents the surface tension (48.5 Pa); 0 represents the angle of contact (9 = 140°); and P represents the pressure (MPa). The extrudates of the invention preferably have a mesoporous volume (Venm - Vioonm) of at Icast 0.3 cmVg, more preferably at least 0.5 cm2/g. The extrudates of the invention preferably have a macroporous volume (Vioonm) of at most 0.5 cm2/g. In a variation, the macroporous volume (Vioonm) is at most 0.3 cm'^/g, more preferably at most 0.1 cm2/g and still more preferably at most 0.08 cmVg. These extrudates normally have a microporous volume (Vo-6nm) of at most 0.55 cm2/g, preferably at most 0.2 cva/g. The microporous volume represents the volume created by pores with a diameter of less than 6 nm. Such a pore distribution which minimises the proportion of pores of less than 6 nm and those of more than 100 nm while increasing the proportion of mesopores (with a diameter in the range 6 nm to 100 nm) is particularly adapted to the diffusional constraints of hydrotreating heavy hydrocarbon cuts. In a preferred variation, the pore distribution over the pore diameter range from 6 nm to 100 nm (mesopores) is extremely narrow at around 15 nm, i.e., in this range the diameter of the majority of pores is in the range 6 nm to 50 nm, preferably in the range 8 nm to 20 nm. The specific surface area (SSA) of the extrudates of the invention is generally at least 120 m^/g, preferably at least 150 mig. This surface area is a BET surface area. The term "BET surface area" means the specific surface area determined by nitrogen adsorption in accordance with the standard ASTM D 3663-78 established using the BRUNAUER-EMMETT-TELLER method described in "The Journal of the American Society" 60, 309 (1938). Preferably, the diameter of the extrudates of the invention is in the range 0.3 to 1.8 mm, more preferably in the range 0.8 to 1.8 mm, and the length is in the range 1 mm to 20 mm, preferably in the range 1 to 10 mm, in particular when the catalyst is used in an ebuUating bed. The average crushing strength (ACS) of these extrudates is generally at least 0.68 daN/mm for 1.6 mm extrudates, preferably at least 1 mm, and the crush strength (CS) is at least 1 MPa. Further, the percentage attrition loss of the extrudates using American standard ASTM D4050 is generally less than 2.5% of the weight of the catalyst. The method of measuring the average crushing strength (ACS) consists of measuring the type of maximum compression which an extrudate can support before it fails, when the product is placed between two planes being displaced at a constant speed of 5 cm/min. Compression is applied perpendicular to one of the extrudate generatrices, and the average crushing strength is expressed as the ratio of the force to the length of the generatrix of the extrudate. The method used to measure the crush strength (CS) consists of subjecting a certain quantity of extrudates to an increasing pressure over a sieve and recovering the fines resulting from crushing the extrudates. The crush strength corresponds to the force exerted to obtain fines representing 0.5% of the weight of the extrudates under test. The attrition test using standard ASTM D4058 consists of rotating a sample of catalyst in a cylinder. The attrition losses are then calculated using the following formula: % attrition loss = 100(1-weight of catalyst over 0.6 mm after test/wt of catalyst of more than 0.6 mm charged into cylinder). The alumina of the invention is essentially constituted by a plurality of juxtaposed agglomerates, each of these agglomerates generally and preferably being partially in the form of packs of flakes and partially in the form of needles, the needles being uniformly dispersed both around the packs of flakes and between the flakes. In general, the length and breadth of the flakes varies between 1 and 5 ^m with a thickness of the order of 10 nm. They can be packed in groups forming a thickness of the order of 0.1 to 0.5 [xm, the groups possibly being separated from each other by a thickness of the order of 0.05 to 0.1 \|im. The needle length can be in the range 0.05 to 0.5 \|am; their cross section is of the order of 10 to 20 nm. These dimensions are given by measuring the extrudates in electron microscope photographs. The alumina flakes principally comprise % alumina and r\ alumina and the needles are y alumina. The flake structure is characteristic of the hydrargillite lineage of alumina, which means that before activation by calcining, these extrudates have the same structure, the flakes being hydrargillite in nature. On calcining, this alumina in its hydrargillite form is principally transformed into dehydrated % and r\ aluminas In contrast, the needle structure is characteristic of a boehmite lineage, meaning that before activation by calcining, these extrudates have the same structure, this alumina being in the form of boehmite. Calcining transforms this boehmite alumina into dehydrated y alumina. The extrudates of the invention are thus obtained by calcining, the extrudates being constituted by hydrargillite alumina-based flakes prior to calcining, the flakes being surrounded at their periphery by boehmite alumina-based needles. The forming process of the invention is more particularly suitable for a starting alumina originating from rapid dehydration of Bayer hydrate (hydrargillite) which is an industrially available aluminium hydroxide and extremely cheap. Such an alumina is in particular obtained by rapid dehydration of hydrargillite using a hot gas stream, the temperature of the gas entering the apparatus generally being between about 400°C and 1200°C, the contact time between the alumina and the hot gases generally being in the range from a fraction of a second to 4-5 seconds; such a process for preparing an alumina powder has been described in French patent FR-Al-1 108 Oil. The alumina obtained can be used as it is or before undergoing step b^, it can be treated to eliminate the alkalis present: a Na20 content of less than 0.5% by weight is preferable. The starting alumina is preferably re-hydrated during step bj so that the boehmite type alumina content is at least 3% by weight, preferably at most 40% by weight. The various steps of these processes for preparing alumina extrudates are described in more detail in a patent application entitled "Alumina extrudates, processes for their preparation and their use as catalysts or catalyst supports" by Rhone-Poulenc Chimie. The catalysts used in the process of the invention can thus be used in ail processes for hydrorefining and hydroconverting hydrocarbon feeds such as petroleum cuts, cuts originating from coal, extracts from bituminous sands and bituminous schists, or hydrocarbons produced from natural gas, more particularly for hydrogenation, hydrodenitrogenation, hydrodeoxygenation, hydrodearomatisation, hydroisomerisation, hydrodealkylation, hydrodewaxing, dehydrogenation, hydrocracking, hydrodesulphuration and hydrodemetallization of carbon-containing feeds containing aromatic compounds and/or olefinic compounds and/or naphthenic compounds and/or paraffininc compounds, the feeds possibly containing metals and/or nitrogen and/or oxygen and/or sulphur. In particular, by modifying the parameters for preparing the essentially alumina-based support, it is possible to obtain different pore distributions and thus to modify the hydrodesulphuration (HDS) and hydrodemetallization (HDM) proportions. Hydrorefining and hydroconversion of hydrocarbon feeds (hydrotreatment) can be carried out in a reactor containing the catalyst of the invention in an ebullating bed. Such hydrotreatments can be applied, for example, to petroleum fractions such as crude oils with an API degree of less than 20, bituminous sand extracts and bituminous schists, atmospheric residues, vacuum residues, asphalts, deasphalted oils, deasphalted vacuum residues, deasphalted crudes, heavy fuels, atmospheric distillates and vacuum distillates, or other hydrocarbons such as liquefied coal products. In an ebullating bed process, the hydrotreatments designed to eliminate impurities such as sulphur, nitrogen or metals, and to reduce the average boiling point of these hydrocarbons are normally carried out at a temperature of about 320°C to about 470°C, preferably about 400°C to about 450°C, at a partial pressure of hydrogen of about 3 MPa (megapascals) to about 30 MPa, preferably 5 to 20 MPa, at a space velocity of about 0.1 to about 6 volumes of feed per volume of catalyst per hour, preferably 0.5 to 2 volumes per volume of catalyst per hour, the ratio of gaseous hydrogen to the liquid hydrocarbon feed being in the range 100 to 3000 standard cubic metres per cubic metre (SmVm^), preferably between 200 and 1200 SmW. Accordingly, the present invention provides a process for hydrotreating a hydrocarbon feed in an ebuUating bed, using a catalyst comprising an essentially alumina-based extruded support, essentially constituted by a plurality of juxtaposed agglomerates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 of the new elements periodic table notation) and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group comprising nickel, iron and cobalt of the new elements periodic table notation), in which the sum S of the group VIB and VIII metals, expressed as the oxides, is in the range 0.5% to 50% by weight, said extruded support being obtained by a starting alumina forming process comprising: either the following steps: -al or a3: starting with an alumina originating from rapid dehydration of hydrargillite; -bl or b3; rehydrating the starting alumina; ci mixing the rehydrated alumina in the presence of an emulsion of at least one hydrocarbon in water, or c3: mixing the rehydrated alumina with a pseudo-boehmite gel, said gel being present in an amount in the range 1% to 30% by weight with respect to the rehydrated alumina and the gel, so as to obtain a paste; dl or d3: extruding the alumina-based paste obtained; el or e3: drying and calcining the extrudates; fl or f3: carrying out a hydrothermal acid treatment in a confined atmosphere on the calcined extrudates; gl or g3: drying and calcining the extrudates from said hydrothermal acid treatment in a confined atmosphere; or the following steps: a2: starting from an alumina originating from rapid dehydration of hydrargillite; b2: forming the alumina into beads in the presence of a pore-forming agent; c2: ageing the alumina beads obtained; d2: mixing the beads from step C2 to obtain a paste which is extruded; e2: drying and calcining the extrudates obtained; f2: carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates from step e2; g2: drying and calcining the extrudates from step e2, said support having a ratio of alumina from boehmite decomposition in The range 5% to 70% by weight, a total pore volume of at least 0.6 cm2/g, and mesopores with an average diameter in the range 15 to 36 mn, a mesoporous volume Venm - Vioonm of at least 0.3 cm /g, a macroporous volume Vioonm of at most 0.5 cm2/g, a microporous volume Vo.6nm of at most 0.55 cm /g, and a specific area of at least 120 m /g., each of said agglomerates being partly in the form of packs of flakes and partly in the form of needles, said needles being uniformly dispersed both about the packs of flakes and between the flakes. The following examples illustrate the invention without limiting its scope. EXAMPLE 1: Preparation of alumina support A forming part of the composition of catalysts Al and A2 of the invention Step aj - starting alumina: The starting material was alumina obtained by very rapid decomposition of hydrargillite in a hot air stream (T = 1000°C). The product obtained was constituted by a mixture of transition aluminas: (khi) and (rho) aluminas. The specific surface area of the product was 300 m /g and the loss on ignition (LOI) was 5%. Step bi - rehydration: The alumina was rehydrated by taking it into suspension in water at a concentration of 500 g/1 at a temperature of 90°C for a period of 48 h in the presence of 0.5% citric acid. After filtering the suspension, a cake of alumina was recovered which was washed with water then dried at a temperature of 140°C for 24 h. The alumina obtained was in the form of a powder, its loss on ignition (LOI), measured by calcining at 1000°G, and its amount of alumina in the form of boehmite, measured by X ray diffraction, are shown in Table L Step Ci - mixing: 10 kg of rehydrated and dried powder was introduced into a 25 1 volume Z blade mixer and an emulsion of hydrocarbon in water stabilised by a surfactant, obtained using a stirred reactor, and 100% nitric acid, was gradually added. The characteristics are shown in Table 1. Mixing was maintained until a consistent homogeneous paste was obtained. After mixing, a 20% ammonia solution was added to neutralise the excess nitric acid, continuing mixing for 3 to 5 min. Step di - extrusion: The paste obtained was introduced into a single screw extruder to obtain raw extrudates with a diameter of 1.6 mm. Step Ci - drying/calcining: The extrudates were then dried at 140°C for 15 h and calcined for 2 h at the temperature shown in Table 1. The calcined support had a specific surface area which was adjusted to between 200 m /g and 130 m/g as indicated in Table 1. Step fi - hydrothermal treatment: The extrudates obtained were impregnated with a solution of nitric and acetic acid in the following concentrations: 3.5% of nitric acid with respect to the weight of alumina and 6.5% of acetic acid with respect to the weight of alumina. They then underwent hydrothermal treatment in a rotating basket autoclave under the conditions defined in Table 1. Step gi - drying/calcining: At the end of this treatment, the extrudates were calcined at a temperature of 550°C for 2 h. The characteristics of the extrudates obtained are shown in Table 1. The amount of boehmite was measured for the extrudates before final calcining. EXAMPLE 2: Preparation of catalyst Al (in accordance with the invention) We dry impregnated the extruded support A of Example 1 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6-4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 12.5% by weight and that of nickel oxide NiO was3.0% by weight. The attrition resistance of the catalyst was evaluated in a rotating drum in accordance with ASTMD4058. The attrition loss was then calculated using the following formula: % attrition loss = 100(l-wt of catalyst of over 0.6 mm after test/weight of catalyst over 0.6 mm charged into cylinder). Catalyst Al had an attrition loss percentage of 0.30% of the weight of the catalyst. EXAMPLE 3: Preparation of catalyst A2 (in accordance vv^ith the invention) We dry impregnated the extruded support of Example 1 with an aqueous solution containing molybdenum salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 12.8%. Catalyst A2 had an attrition loss percentage of 0.32% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 4: Preparation of alumina support B forming part of the composition of catalyst B of the invention The alumina constituting this support was prepared using the same sequence of steps as the alumina of support A but using different conditions during the mixing step and the drying/calcining step after extrusion (see Table 1). The characteristics of the extrudates obtained are shown in Table 1. The amount of boehmite was measured for the extrudates before final calcining. EXAMPLE 5: Preparation of catalyst B (in accordance with the invention) We dry impregnated the extruded support of Example 4 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 6.5% by weight and that of nickel oxide NiO was 1.5% by weight. Catalyst B had an attrition loss percentage of 0.50% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 6: Preparation of alumina support C forming part of the composition of catalysts CI and C2 in accordance M^ith the invention. The same steps of Example 1 were used except that mixing step bi was carried out as follows. Step bi - mixing: This was a continuous process carried out in a co-rotating twin screw mixer. Upstream of the mixer, the rehydrated and dried alumina was introduced at a rate of 90 kg/h. An emulsion of petroleum in water was prepared in a stirred reactor, by introducing: • 5.46 kg of water; • 10.04 kg of 69% nitric acid; • 10.4 kg of petroleum; • 1.56kgofSoprophorSC138. This emulsion was introduced into the primer of the twin screw machine at a rate of 27.46 kg/h immediately following introduction of the alumina powder. After machining, a 28% ammonia solution was introduced at a rate of 4.34 kg/h. The passage time for the powder in the machine was of the order of 50 to 60s. A homogeneous paste which could be extruded was obtained from the machine outlet. The characteristics of the extrudates obtained are shown in Table 1. The boehmite content was measured for the extrudates prior to final calcining. EXAMPLE 7: Preparation of catalyst CI (in accordance with the invention) We dry impregnated the extruded support of Example 6 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 13.0% by weight and that of nickel oxide NiO was 3.2% by weight. Catalyst CI had an attrition loss percentage of 0.35% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 8: Preparation of catalyst C2 (in accordance with the invention) We dry impregnated the extruded support of Example 6 with an aqueous solution containing nickel salts. The nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final nickel oxide NiO was 5.9% by weight. Catalyst C2 had an attrition loss percentage of 0.33% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 9: Preparation of alumina support D forming part of the composition of catalyst D (comparative) The alumina constituting support D was prepared using the same procedures as support A except that hydrothermal treatment step el was omitted. The characteristics of the calcined extrudates are shown in Table 2. EXAMPLE 10: Preparation of catalyst D (comparative) We dry impregnated the extruded support of Example 9 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 10.2% by weight and that of nickel oxide NiO was 2.5% by weight. Catalyst D had an attrition loss percentage of 0.6% of the weight of the catalyst, calculated using the attrition test described in Example 3. EXAMPLE 11: Hydroconversion tests for petroleum residues using catalysts Al, A2, B, CI, C2 and D Catalysts Al, A2, B, CI, C2 and D described above were compared in a pilot unit comprising a tube reactor provided with an apparatus for permanently maintaining ebuUation of the catalyst inside the reactor. The pilot unit was representative of an industrial H-Oil ebullating bed residue hydroconversion reactor described in a number of patents, for example US-A-4 521 295 and US-A-4 495 060. The pilot reactor was charged with 1 litre of catalyst in extrudate form as described above. Once in an ebullating bed mode, the expanded catalyst occupied a volume of 1.5 1 in the reactor. The unit was operated with the above residue under the following operating conditions: • pressure = 16 MPa; • hydrogen flow rate: 600 std 1. H2/I of feed; • hourly space velocity = 0.3 m of feed/m of reactor/h" . The temperature was adjusted to about 420-430°C so that all of the catalysts led to 65% by weight conversion of the 550°C'fraction. The HDS and HDM performances were compared after 2 weeks of test. The HDS ratio is defined as follows: HDS (wt %) = ((wt % S)feed - (wt % S)test)/(wt % S)feed 100 The HDM ratio is defined as follows: HDM (wt %) = ((ppm wt Ni+V)feed - (ppm wt Ni+V)test)/ (ppm wt Ni+V)feed * 100. The degree of conversion is defined as follows: Conversion (wt %) = ((wt % of 550°C+)feed - (wt % of 550°C+)test)/(%wt % of 550°C+)feed * 100. The stability of the products obtained was evaluated using a "P value Shell" method carried out on the 350°C'fraction of the effluent recovered after the test. The following table compares the HDS, HDM and P Value Shell values obtained with catalysts Al, A2, B, CI, C2 and D for 65% by weight of conversion of the 550°C* fraction. It thus appears that the catalysts in the form of extrudates of the present invention can achieve high degrees of conversion of the 550°C"fraction of an oil residue and result in stable products. These catalysts can also significantly hydrodesulphurise and hydrodemetaUise the residue and produce light fractions (diesel, gasoline) which satisfy refiners' specifications. By adjusting the alumina preparation parameters, it is possible to obtain different pore distributions and thus modify the degrees of HDS, HDM and certain petroleum qualities of the effluents from the units such as the stability of the residual 350°C"fraction. WE CLAIM: 1. A process for hydrotreating a hydrocarbon feed in an ebullating bed, using a catalyst comprising an essentially alumina-based extruded support, essentially constituted by a plurality of juxtaposed agglomerates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 of the new elements periodic table notation) and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group comprising nickel, iron and cobalt of the new elements periodic table notation), in which the sum S of the group VIB and VIII metals, expressed as the oxides, is in the range 0.5% to 50% by weight, said extruded support being obtained by a starting alumina forming process comprising: either the following steps: al or a3: starting with an alumina originating from rapid dehydration of hydrargillite; bl or b3; rehydrating the starting alumina; C1 mixing the rehydrated alumina in the presence of an emulsion of at least one hydrocarbon in water, or c3: mixing the rehydrated alumina with a pseudo-boehmite gel, said gel being present in an amount in the range 1% to 30%» by weight with respect to the rehydrated alumina and the gel, so as to obtain a paste; d1 or d3: extruding the alumina-based paste obtained; el or e3: drying and calcining the extrudates; fl or f3: carrying out a hydrothermal acid treatment in a confined atmosphere on the calcined extrudates; gl or g3: drying and calcining the extrudates from said hydrothermal acid treatment in a confined atmosphere; or the following steps: a2: starting from an alumina originating from rapid dehydration of hydrargillite; b2: forming the alumina into beads in the presence of a pore-forming agent; c2: ageing the alumina beads obtained; d2: mixing the beads from step C2 to obtain a paste which is extruded; e2: drying and calcining the extrudates obtained; f2: carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates from step e2; g2: drying and calcining the extrudates from step e2, said support having a ratio of alumina from boehmite decomposition in the range 5% to 70% by weight, a total pore volume of at least 0.6 cm2/g, and mesopores with an average diameter in the range 15 to 36 nm, a mesoporous volume V6mm - V100mm of at least 0.3 cm2/g, a macroporous volume V100mm of at most 0.5 cm2/g, a microporous volume V0-6mm of at most 0.55 cmVg, and a specific area of at least 120 m3/g., each of said agglomerates being partly in the form of packs of flakes and partly in the form of needles, said needles being uniformly dispersed both about the packs of flakes and between the flakes. 2. The process according to claim 1, in which said extruded support is obtained by a preparation process comprising the steps al, bl, cl, dl, el, fl, gl, and in which the alumina from bl comprises at least 3% weight of boehmite. 3. The process according to anyone of claims 1 or 2, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIII and at least one catalytic metal or compound of a catalytic metal from group VIB, and said metals are introduced at least in part separately or simultaneously by impregnation or co-mixing with the support. 4. The process according to anyone of claims 1 to 3, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIB, said metal or compound of a catalytic metal from group VIB is molybdenum or tungsten, and the catalytic metal or the compound of a catalytic metal from group VIII is iron, nickel or cobalt. 5. The process according to anyone of claims 1 to 4, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIB, said metal or compound of a catalytic metal from group VIB is molybdenum, and the catalytic metal or the compound of a catalytic metal from group VIII is nickel. 6. The process according to any one of claims 1 to 7, in which the diameter of the alumina extrudates is in the range 0.3 to 1.8 mm. 7. The process according to anyone of claims 1 to 6, for hydrodesulphurization and hydrodemetallation of carbonaceous feedstocks comprising aromatic and/or olefinic, and/or naphtenic, and/or paraffinic compounds, said feedstocks comprising sulphur-, metals, and optionally nitrogen, and/or oxygen. 8. The process according to any one of claims 1 to 7, for hydrodesulphurization of carbonaceous feedstocks comprising aromatic and/or olefinic, and/or naphtenic, and/or paraffinic compounds, said feedstocks comprising sulphur, and optionally nitrogen, and/or oxygen. 9. The process according to any one of claims 1 to 8, that is carried out at a temperature of 320°C to 470°C, under a partial pressure of hydrogen of 3 MPa to 30 MPa, at a space velocity of 0.1 to 6 volumes of feed per volume of catalyst per hour, the ratio of gaseous hydrogen over the liquid hydrocarbon feed being in the range 100 to 3000 standard cubic metres per cubic metre (Sm3/m3). 10. A process for hydrotreating a hydrocarbon feed in an ebuUating bed substantially as herein described with reference to the accompanying drawings.

Full Text

The present invention relates to the use of a catalyst for hydrorefining and/or hydroconverting hydrocarbon feeds (also known as hydrotreatment) in an ebullating bed reactor, the catalyst comprising an essentially alumina-based support in the form of extrudates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt.
The present invention thus particularly relates to the use of the catalyst in a process for hydrorefining and/or hydroconverting hydrocarbon feeds such as petroleum cuts, cuts originating from coal, or hydrocarbons produced from natural gas. The hydrorefining and/or hydroconversion process of the invention comprises at least one three-phase reactor containing the hydrorefining and/or hydroconversion catalyst in an ebullating bed.
This type of operation has been described, for example, in United States patents US-A-4 251295 or US-A-4 495 060 which describe the H-OIL process.
Hydrotreatment of hydrocarbon feeds, such as sulphur-containing petroleum cuts, is becoming more and more important in refining with the increasing need to reduce the quantity of sulphur in petroleum cuts and to convert heavy fractions into lighter fractions which can be upgraded as a fuel. Both to satisfy the specifications imposed in every country for commercial fuels and for economical reasons, imported crudes which are becoming richer and richer in heavy fractions and in heteroatoms and more and more depleted in hydrogen must be upgraded to the best possible extent. This upgrading implies a relatively large reduction in the average molecular weight of heavy constituents, which can be

obtained, for example, by cracking or hydrocracking the pre-refined feeds, i.e., desulphurized and denitrogenated feeds. Van Kessel et al explained this subject in detail in an article published in the review "Oil & Gas Journal", 16'*February 1987, pages 55 to 66.
The skilled person is aware that during hydrotreatment of petroleum fractions containing organometallic complexes, the majority of those complexes are destroyed in the presence of hydrogen, hydrogen sulphide, and a hydrotreatment catalyst. The constituent metal of such complexes then precipitates out in the form of a solid sulphide which then becomes fixed on the internal surface of the pores. This is particularly the case for vanadium, nickel, iron, sodium, titanium, silicon, and copper complexes which are naturally present to a greater or lesser extent in crude oils depending on the origin of the crude and which, during distillation, tend to concentrate in the high boiling point fractions and in particular in the residues. This is also the case for liquefied coal products which also comprise metals, in particular iron and titanium. The general term hydrodemetallization (HDM) is used to designate those organometallic complex destruction reactions in hydrocarbons.
The accumulation of solid deposits in the catalyst pores can continue until a portion of the pores controlling access of reactants to a fraction of the interconnected pore network is completely blocked so that that fraction becomes inactive even if the pores of that fraction are only slightly blocked or even intact. That phenomenon can cause premature and very severe catalyst deactivation. It is particularly sensitive in hydrodemetallization reactions carried out in the presence of a supported heterogeneous catalyst. The term "heterogeneous" means not soluble in the hydrocarbon feed. In that case, it has been shown that pores at the grain periphery are blocked more quickly than central pores. Similarly, the pore mouths block up more quickly than their other portions. Pore blocking is

accompanied by a gradual reduction in their diameter which increasingly limits molecule diffusion and increases the concentration gradient, thus accentuating the heterogeneity of the deposit from the periphery to the interior of the porous particles to the point that the pores opening to the outside are very rapidly blocked: access to the practically intact internal pores of the particles is thus denied to the reactants and the catalyst is prematurely deactivated.
The phenomenon described above is known as pore mouth plugging. Proof of its existence and an analysis of its causes have been published a number of times' in the international scientific literature, for example: "Catalyst deactivation through pore mouth plugging" presented at the 5 International Chemical Engineering Symposium at Houston, Texas, U. S. A., March 1978, or "Effects of feed metals on catalyst ageing in hydroprocessing residuum" in Industrial Engineering Chemistry Process Design and Development, volume 20, pages 262 to 273 published in 1981 by the American Chemical Society, or more recently in "Effect of catalyst pore structure on hydrotreating of heavy oil" presented at the National conference of the American Chemical Society at Las Vegas, U. S. A., 30 March 1982.
A catalyst for hydrotreatment of heavy hydrocarbon cuts containing metals must thus be composed of a catalytic support with a porosity profile which is particularly suitable for the specific diffusional constraints of hydrotreatment, in particular hydrodemetallization.
The catalysts usually used for hydrotreatment processes are composed of a support on which metal oxides such as cobalt, nickel or molybdenum oxides are deposited. The catalyst is then sulphurated to transformed all or part of the metal oxides into metal sulphide phases. The support is generally alumina-based, its role consisting of dispersing the active phase and providing a texture which can capture metal impurities, while avoiding the blocking problems mentioned above.

Catalysts with a particular pore distribution have been described in United States patent US-A-4 395 329. There are two types of prior art alumina-based supports. Firstly, alumina extrudates exist that are prepared from an alumina gel. Hydrotreatment catalysts prepared from such extrudates have a number of disadvantages. Firstly, the process for preparing the alumina gel is particularly polluting, in contrast to that of alumina originating from rapid dehydration of hydrargillite, known as flash alumina. The pores of alumina gel based supports are particularly suitable for hydrodesulphuration and hydrotreatment of light hydrocarbons, and not for other types of hydrotreatment. Further, even though such extrudates are balanced in their hydrodemetallization/hydrodesulphuration ratio, their hydrometallization retention capacity is low, in general at most 30% by weight, so they are rapidly saturated and have to be replaced. Further, considering the high production cost of the alumina gel, the manufacture of such catalysts is very expensive.
Secondly, alumina beads prepared by rapid dehydration of hydrargillite then agglomerating the flash alumina powder obtained are used as a support for catalysts for hydrotreating hydrocarbon feeds containing metals. The cost of preparing these beads is lower, however in order to maintain it at a satisfactory level, beads with a diameter of more than 2 mm have to be prepared. As a result, the metals cannot be introduced right into the core of the beads, and the catalytic phase located there is not used.
Hydrotreatment catalysts prepared from flash alumina extrudates which are smaller and which have a porosity which is suitable for hydrotreatment would not have all of those disadvantages, but there is currently no industrial process for preparing such catalysts.
The present invention concerns the use of a catalyst for hydrotreating carbon-containing fractions in hydrotreatment reactions, in particular

hydrogenation, hydrodenitrogenation, hydrodeoxygenation, hydrodearomatization, hydroisomerisation, hydrodealkylation, hydrodewaxing, hydrocracking, and hydrodesulphuration with a hydrodemetallization activity which is at least equivalent to that of catalysts currently known to the skilled person, to obtain particularly good hydrotreatment results with respect to prior art products.
The catalyst of the invention comprises an essentially alumina-based support in the form of extrudates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt, more preferably nickel.
The extruded support used in the catalyst of the invention is generally and preferably essentially based on alumina agglomerates, the alumina agglomerates generally and preferably being obtained by forming a starting alumina originating from rapid dehydration of hydrargilite, and generally having a total pore volume of at least 0.6 cm3g, an average mesoporous diameter in the range 15 to 36 nm (nanometers), and generally a quantity of alumina originating from boehmite decomposition in the range 5% to 70% by weight. The term "alumina originating from boehmite decomposition" means that during the extrudate preparation process, boehmite type alumina is produced to the point of representing 5% to 70% by weight of the total alumina, then decomposed. This quantity of alumina from boehmite decomposition is measured by X ray diffraction of the alumina before decomposing the boehmite.
The extruded support of the catalyst of the invention can also be obtained by extruding a mixture of varying proportions of an alumina powder from rapid dehydration of hydrargillite (flash alumina) and at least one alumina gel obtained.

for example, by precipitating aluminium salts such as aluminium chloride, aluminium sulphate, aluminium nitrate, or aluminium acetate, or by hydrolysis of aluminium alkoxides such as aluminium triethoxide. Such mixtures of flash alumina and alumina gel contain less than 50% by weight of alumina gel, preferably 1% to 45% of alumina gel.
The catalyst used in the process of the invention can be prepared using any method which is known to the skilled person, more particularly using the methods described below.
The support is formed by alumina extrudates with a diameter generally in the range 0.3 to 1.8 mm, preferably 0.8 to 1.8 mm, when the catalyst is used in an ebullating bed, the extrudates having the characteristics described above. Any known method can be used for the optional introduction of the catalytic metals, at any stage of the preparation, preferably by impregnation or co-mixing, onto the extrudates or prior to their forming by extrusion, the optional catalytic metals being at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 in the new periodic table notation), preferably molybdenum or tungsten, more preferably molybdenum, and/or optionally at least one catalytic metal or a compound of a catalytic metal from group VIII (group 8, 9 and 10 in the new periodic table notation), preferably iron, nickel or cobalt, more preferably nickel. The metals can optionaDy be mixed with the support by co-mixing at any step of the support preparation process. When there are a plurality, at least part of the group VIB and VIII metals can optionally be introduced separately or simultaneously during impregnation or co-mixing with the support, at any stage of forming or preparation.
As an example, the catalyst of the invention can be prepared using a preparation process comprising the following steps:

with at least one compound of a catalytic metal from group VIB and/or at least one compound of a catalytic metal from group VIII, optionally followed by ageing, and/or drying, then optional calcining; b) forming by extruding the product obtained from step a).
The metals cited above are usually introduced into the catalyst in the form of precursors such as oxides, acids, salts, or organic complexes. The sum S of the group VIB and VIII metals, expressed as the oxides introduced into the catalysts, is in the range 0 to 50% by weight, preferably 0.5% to 50% by weight, more preferably 0.5% to 40% by weight. It is thus possible to use the support as a catalyst without introducing a catalytic metal into the catalyst.
The preparation then generally comprises ageing and drying, then generally a heat treatment, for example calcining, at a temperature in the range 400°C to 800°C.
The support the use of which is one of the essentially elements of the invention is essentially alumina-based. The support used in the catalyst of the invention is generally and preferably obtained by forming a starting alumina originating from rapid dehydration of hydrargillite, forming preferably being carried out using one of the processes described below.
Processes for preparing the support of the invention are described below for a support constituted by alumina. When the support contains one or more other compounds, the compound or compounds or a precursor of the compound or compounds may be introduced at any stage in the process for preparing the support of the invention. It is also possible to introduce the compound or compounds by impregnating the formed alumina using the compound or compounds or any precursor of the compound or compounds.

A first process for forming a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps:
a, starting with an alumina originating from rapid dehydration of
hydrargillite;
b] rehydrating the starting alumina;
Ci mixing the rehydrated alumina in the presence of an emulsion of at least
one hydrocarbon in water;
di extruding the alumina-based paste obtained from step Cj;
ei drying and calcining the extrudates;
fi carrying out a hydrothermal acid treatment in a confined atmosphere on
the extrudates from step ei;
gi drying and calcining the extrudates from step fj.
A second process for forming the alumina from a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps:
a2 starting from an alumina originating from rapid dehydration of
hydrargillite;
ba forming the alumina into beads in the presence of a pore-forming agent;
C2 ageing the alumina beads obtained;
d2 mixing the beads from step C2 to obtain a paste which is extruded;
62 drying and calcining the extrudates obtained;
f2 carrying out a hydrothermal acid treatment in a confined atmosphere on
the extrudates obtained from step 62;
g2 drying and calcining the extrudates from step f2.
A third process for forming an alumina from a starting alumina originating from rapid dehydration of hydrargillite comprises the following steps:
a3 starting from an alumina originating from rapid dehydration of
hydrargillite;

b3 rehydrating the starting alumina;
C3 mixing the rehydrated alumina with a pseudo-boehmite gel, the gel being
present in an amount in the range 1% to 30% by weight with respect to the
rehydrated alumina and the gel;
d3 extruding the alumina-based paste obtained from step 03;
e3 drying and calcining the extrudates obtained;
f3 carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates obtained from step e3;
g3 optionally drying then calcining the extrudates from step f3.
This process uses identical steps to steps ai, bi, di, ei, fi and gi of the first process described above.
The alumina extrudates of the invention generally and preferably have a total pore volume (TPV) of at least 0.6 cm /g, preferably at least 0.65 cm /g.
The TPV is measured as follows: the grain density and absolute density are determined: the grain densities (Dg) and absolute densities (Da) are measured using a mercury and helium picnometry method respectively, then the TPV is given by the formula:
The average mesoporous diameter of the extrudates of the invention is also generally and preferably in the range 15 to 36 nm (manometers). The average mesoporous diameter for the given extrudates is measured using a graph of the pore distribution of said extrudates. It is the diameter for which the associated

over 100 nm (macropores), or the macroporous volume;

Venm represents the volume created by pores with a diameter of over 6 nm;
Venm - Viooam represents the mesoporous volume, i.e., the volume created by pores with a diameter in the range 6 nm and 100 nm, i.e., the volume created by all the pores with a size in the range 6 nm to 100 nm (mesopores).
These volumes are measured using the mercury penetration technique in which the Kelvin law is applied which defines a relationship between the pressure, the diameter of the smallest pore into which the diameter penetrates at that pressure, the wetting angle and the surface tension in the following formula: 0 = (4tcose).lO/P
where
0 represents the pore diameter (in nm);
t represents the surface tension (48.5 Pa);
0 represents the angle of contact (9 = 140°); and
P represents the pressure (MPa).
The extrudates of the invention preferably have a mesoporous volume (Venm - Vioonm) of at Icast 0.3 cmVg, more preferably at least 0.5 cm2/g.
The extrudates of the invention preferably have a macroporous volume (Vioonm) of at most 0.5 cm2/g. In a variation, the macroporous volume (Vioonm) is at most 0.3 cm'^/g, more preferably at most 0.1 cm2/g and still more preferably at most 0.08 cmVg.
These extrudates normally have a microporous volume (Vo-6nm) of at most 0.55 cm2/g, preferably at most 0.2 cva/g. The microporous volume represents the volume created by pores with a diameter of less than 6 nm.
Such a pore distribution which minimises the proportion of pores of less than 6 nm and those of more than 100 nm while increasing the proportion of mesopores (with a diameter in the range 6 nm to 100 nm) is particularly adapted to the diffusional constraints of hydrotreating heavy hydrocarbon cuts.

In a preferred variation, the pore distribution over the pore diameter range from 6 nm to 100 nm (mesopores) is extremely narrow at around 15 nm, i.e., in this range the diameter of the majority of pores is in the range 6 nm to 50 nm, preferably in the range 8 nm to 20 nm.
The specific surface area (SSA) of the extrudates of the invention is generally at least 120 m^/g, preferably at least 150 mig. This surface area is a BET surface area. The term "BET surface area" means the specific surface area determined by nitrogen adsorption in accordance with the standard ASTM D 3663-78 established using the BRUNAUER-EMMETT-TELLER method described in "The Journal of the American Society" 60, 309 (1938).
Preferably, the diameter of the extrudates of the invention is in the range 0.3 to 1.8 mm, more preferably in the range 0.8 to 1.8 mm, and the length is in the range 1 mm to 20 mm, preferably in the range 1 to 10 mm, in particular when the catalyst is used in an ebuUating bed.
The average crushing strength (ACS) of these extrudates is generally at least 0.68 daN/mm for 1.6 mm extrudates, preferably at least 1 mm, and the crush strength (CS) is at least 1 MPa. Further, the percentage attrition loss of the extrudates using American standard ASTM D4050 is generally less than 2.5% of the weight of the catalyst.
The method of measuring the average crushing strength (ACS) consists of measuring the type of maximum compression which an extrudate can support before it fails, when the product is placed between two planes being displaced at a constant speed of 5 cm/min.
Compression is applied perpendicular to one of the extrudate generatrices, and the average crushing strength is expressed as the ratio of the force to the length of the generatrix of the extrudate.

The method used to measure the crush strength (CS) consists of subjecting a certain quantity of extrudates to an increasing pressure over a sieve and recovering the fines resulting from crushing the extrudates. The crush strength corresponds to the force exerted to obtain fines representing 0.5% of the weight of the extrudates under test. The attrition test using standard ASTM D4058 consists of rotating a sample of catalyst in a cylinder. The attrition losses are then calculated using the following formula:
% attrition loss = 100(1-weight of catalyst over 0.6 mm after test/wt of catalyst of more than 0.6 mm charged into cylinder).
The alumina of the invention is essentially constituted by a plurality of juxtaposed agglomerates, each of these agglomerates generally and preferably being partially in the form of packs of flakes and partially in the form of needles, the needles being uniformly dispersed both around the packs of flakes and between the flakes.
In general, the length and breadth of the flakes varies between 1 and 5 ^m with a thickness of the order of 10 nm. They can be packed in groups forming a thickness of the order of 0.1 to 0.5 [xm, the groups possibly being separated from each other by a thickness of the order of 0.05 to 0.1 |im.
The needle length can be in the range 0.05 to 0.5 |am; their cross section is of the order of 10 to 20 nm. These dimensions are given by measuring the extrudates in electron microscope photographs. The alumina flakes principally comprise % alumina and r\ alumina and the needles are y alumina.
The flake structure is characteristic of the hydrargillite lineage of alumina, which means that before activation by calcining, these extrudates have the same structure, the flakes being hydrargillite in nature. On calcining, this alumina in its hydrargillite form is principally transformed into dehydrated % and r\ aluminas

In contrast, the needle structure is characteristic of a boehmite lineage, meaning that before activation by calcining, these extrudates have the same structure, this alumina being in the form of boehmite. Calcining transforms this boehmite alumina into dehydrated y alumina.
The extrudates of the invention are thus obtained by calcining, the extrudates being constituted by hydrargillite alumina-based flakes prior to calcining, the flakes being surrounded at their periphery by boehmite alumina-based needles.
The forming process of the invention is more particularly suitable for a starting alumina originating from rapid dehydration of Bayer hydrate (hydrargillite) which is an industrially available aluminium hydroxide and extremely cheap.
Such an alumina is in particular obtained by rapid dehydration of hydrargillite using a hot gas stream, the temperature of the gas entering the apparatus generally being between about 400°C and 1200°C, the contact time between the alumina and the hot gases generally being in the range from a fraction of a second to 4-5 seconds; such a process for preparing an alumina powder has been described in French patent FR-Al-1 108 Oil.
The alumina obtained can be used as it is or before undergoing step b^, it can be treated to eliminate the alkalis present: a Na20 content of less than 0.5% by weight is preferable.
The starting alumina is preferably re-hydrated during step bj so that the boehmite type alumina content is at least 3% by weight, preferably at most 40% by weight.
The various steps of these processes for preparing alumina extrudates are described in more detail in a patent application entitled "Alumina extrudates, processes for their preparation and their use as catalysts or catalyst supports" by Rhone-Poulenc Chimie.

The catalysts used in the process of the invention can thus be used in ail
processes for hydrorefining and hydroconverting hydrocarbon feeds such as
petroleum cuts, cuts originating from coal, extracts from bituminous sands and
bituminous schists, or hydrocarbons produced from natural gas, more particularly
for hydrogenation, hydrodenitrogenation, hydrodeoxygenation,
hydrodearomatisation, hydroisomerisation, hydrodealkylation, hydrodewaxing, dehydrogenation, hydrocracking, hydrodesulphuration and hydrodemetallization of carbon-containing feeds containing aromatic compounds and/or olefinic compounds and/or naphthenic compounds and/or paraffininc compounds, the feeds possibly containing metals and/or nitrogen and/or oxygen and/or sulphur. In particular, by modifying the parameters for preparing the essentially alumina-based support, it is possible to obtain different pore distributions and thus to modify the hydrodesulphuration (HDS) and hydrodemetallization (HDM) proportions.
Hydrorefining and hydroconversion of hydrocarbon feeds (hydrotreatment) can be carried out in a reactor containing the catalyst of the invention in an ebullating bed. Such hydrotreatments can be applied, for example, to petroleum fractions such as crude oils with an API degree of less than 20, bituminous sand extracts and bituminous schists, atmospheric residues, vacuum residues, asphalts, deasphalted oils, deasphalted vacuum residues, deasphalted crudes, heavy fuels, atmospheric distillates and vacuum distillates, or other hydrocarbons such as liquefied coal products. In an ebullating bed process, the hydrotreatments designed to eliminate impurities such as sulphur, nitrogen or metals, and to reduce the average boiling point of these hydrocarbons are normally carried out at a temperature of about 320°C to about 470°C, preferably about 400°C to about 450°C, at a partial pressure of hydrogen of about 3 MPa (megapascals) to about 30 MPa, preferably 5 to 20 MPa, at a space velocity of about 0.1 to about 6 volumes of feed per volume of catalyst per hour, preferably 0.5 to 2 volumes per

volume of catalyst per hour, the ratio of gaseous hydrogen to the liquid hydrocarbon feed being in the range 100 to 3000 standard cubic metres per cubic metre (SmVm^), preferably between 200 and 1200 SmW.
Accordingly, the present invention provides a process for hydrotreating a hydrocarbon feed in an ebuUating bed, using a catalyst comprising an essentially alumina-based extruded support, essentially constituted by a plurality of juxtaposed agglomerates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 of the new elements periodic table notation) and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group comprising nickel, iron and cobalt of the new elements periodic table notation), in which the sum S of the group VIB and VIII metals, expressed as the oxides, is in the range 0.5% to 50% by weight, said extruded support being obtained by a starting alumina forming process comprising: either the following steps: -al or a3: starting with an alumina originating from rapid dehydration of hydrargillite; -bl or b3; rehydrating the starting alumina; ci mixing the rehydrated alumina in the presence of an emulsion of at least one hydrocarbon in water, or c3: mixing the rehydrated alumina with a pseudo-boehmite gel, said gel being present in an amount in the range 1% to 30% by weight with respect to the rehydrated alumina and the gel, so as to obtain a paste; dl or d3: extruding the alumina-based paste obtained; el or e3: drying and calcining the extrudates; fl or f3: carrying out a hydrothermal acid treatment in a confined atmosphere on the calcined extrudates; gl or g3: drying and calcining the extrudates from said hydrothermal acid treatment in a confined atmosphere; or the following steps: a2: starting from an alumina originating from rapid dehydration of hydrargillite; b2: forming the alumina into beads in the presence of a pore-forming agent; c2: ageing the alumina beads obtained; d2: mixing the beads from step C2 to obtain a paste which is extruded; e2: drying and calcining the extrudates obtained; f2:

carrying out a hydrothermal acid treatment in a confined atmosphere on the extrudates from step e2; g2: drying and calcining the extrudates from step e2, said support having a ratio of alumina from boehmite decomposition in The range 5% to 70% by weight, a total pore volume of at least 0.6 cm2/g, and mesopores with an average diameter in the range 15 to 36 mn, a mesoporous volume Venm - Vioonm of at least 0.3 cm /g, a macroporous volume Vioonm of at most 0.5 cm2/g, a microporous volume Vo.6nm of at most 0.55 cm /g, and a specific area of at least 120 m /g., each of said agglomerates being partly in the form of packs of flakes and partly in the form of needles, said needles being uniformly dispersed both about the packs of flakes and between the flakes.

The following examples illustrate the invention without limiting its scope. EXAMPLE 1: Preparation of alumina support A forming part of the composition of catalysts Al and A2 of the invention Step aj - starting alumina: The starting material was alumina obtained by very rapid decomposition of hydrargillite in a hot air stream (T = 1000°C). The product obtained was constituted by a mixture of transition aluminas: (khi) and (rho) aluminas. The specific surface area of the product was 300 m /g and the loss on ignition (LOI) was 5%.
Step bi - rehydration: The alumina was rehydrated by taking it into suspension in water at a concentration of 500 g/1 at a temperature of 90°C for a period of 48 h in the presence of 0.5% citric acid.
After filtering the suspension, a cake of alumina was recovered which was washed with water then dried at a temperature of 140°C for 24 h.
The alumina obtained was in the form of a powder, its loss on ignition (LOI), measured by calcining at 1000°G, and its amount of alumina in the form of boehmite, measured by X ray diffraction, are shown in Table L Step Ci - mixing: 10 kg of rehydrated and dried powder was introduced into a 25 1 volume Z blade mixer and an emulsion of hydrocarbon in water stabilised by a surfactant, obtained using a stirred reactor, and 100% nitric acid, was gradually added. The characteristics are shown in Table 1.
Mixing was maintained until a consistent homogeneous paste was obtained.
After mixing, a 20% ammonia solution was added to neutralise the excess nitric acid, continuing mixing for 3 to 5 min.

Step di - extrusion: The paste obtained was introduced into a single screw
extruder to obtain raw extrudates with a diameter of 1.6 mm.
Step Ci - drying/calcining: The extrudates were then dried at 140°C for 15 h and
calcined for 2 h at the temperature shown in Table 1. The calcined support had a
specific surface area which was adjusted to between 200 m /g and 130 m/g as
indicated in Table 1.
Step fi - hydrothermal treatment: The extrudates obtained were impregnated
with a solution of nitric and acetic acid in the following concentrations: 3.5% of
nitric acid with respect to the weight of alumina and 6.5% of acetic acid with
respect to the weight of alumina. They then underwent hydrothermal treatment in
a rotating basket autoclave under the conditions defined in Table 1.
Step gi - drying/calcining: At the end of this treatment, the extrudates were
calcined at a temperature of 550°C for 2 h.
The characteristics of the extrudates obtained are shown in Table 1.
The amount of boehmite was measured for the extrudates before final calcining.

EXAMPLE 2: Preparation of catalyst Al (in accordance with the invention)
We dry impregnated the extruded support A of Example 1 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6-4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 12.5% by weight and that of nickel oxide NiO was3.0% by weight.
The attrition resistance of the catalyst was evaluated in a rotating drum in accordance with ASTMD4058. The attrition loss was then calculated using the following formula:
% attrition loss = 100(l-wt of catalyst of over 0.6 mm after test/weight of catalyst over 0.6 mm charged into cylinder).
Catalyst Al had an attrition loss percentage of 0.30% of the weight of the catalyst. EXAMPLE 3: Preparation of catalyst A2 (in accordance vv^ith the invention)
We dry impregnated the extruded support of Example 1 with an aqueous solution containing molybdenum salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 12.8%.
Catalyst A2 had an attrition loss percentage of 0.32% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 4: Preparation of alumina support B forming part of the composition of catalyst B of the invention

The alumina constituting this support was prepared using the same sequence of steps as the alumina of support A but using different conditions during the mixing step and the drying/calcining step after extrusion (see Table 1).
The characteristics of the extrudates obtained are shown in Table 1.
The amount of boehmite was measured for the extrudates before final calcining. EXAMPLE 5: Preparation of catalyst B (in accordance with the invention)
We dry impregnated the extruded support of Example 4 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 6.5% by weight and that of nickel oxide NiO was 1.5% by weight.
Catalyst B had an attrition loss percentage of 0.50% of the weight of the catalyst, calculated using the attrition test described in Example 2.
EXAMPLE 6: Preparation of alumina support C forming part of the composition of catalysts CI and C2 in accordance M^ith the invention.
The same steps of Example 1 were used except that mixing step bi was carried out as follows.
Step bi - mixing: This was a continuous process carried out in a co-rotating twin screw mixer.
Upstream of the mixer, the rehydrated and dried alumina was introduced at a rate of 90 kg/h. An emulsion of petroleum in water was prepared in a stirred reactor, by introducing:
• 5.46 kg of water;
• 10.04 kg of 69% nitric acid;

• 10.4 kg of petroleum;
• 1.56kgofSoprophorSC138.
This emulsion was introduced into the primer of the twin screw machine at a rate of 27.46 kg/h immediately following introduction of the alumina powder.
After machining, a 28% ammonia solution was introduced at a rate of 4.34 kg/h.
The passage time for the powder in the machine was of the order of 50 to 60s.
A homogeneous paste which could be extruded was obtained from the machine outlet.
The characteristics of the extrudates obtained are shown in Table 1.
The boehmite content was measured for the extrudates prior to final calcining. EXAMPLE 7: Preparation of catalyst CI (in accordance with the invention)
We dry impregnated the extruded support of Example 6 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 13.0% by weight and that of nickel oxide NiO was 3.2% by weight.
Catalyst CI had an attrition loss percentage of 0.35% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 8: Preparation of catalyst C2 (in accordance with the invention)
We dry impregnated the extruded support of Example 6 with an aqueous solution containing nickel salts. The nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the

impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final nickel oxide NiO was 5.9% by weight.
Catalyst C2 had an attrition loss percentage of 0.33% of the weight of the catalyst, calculated using the attrition test described in Example 2. EXAMPLE 9: Preparation of alumina support D forming part of the composition of catalyst D (comparative)
The alumina constituting support D was prepared using the same procedures as support A except that hydrothermal treatment step el was omitted.
The characteristics of the calcined extrudates are shown in Table 2.

EXAMPLE 10: Preparation of catalyst D (comparative)
We dry impregnated the extruded support of Example 9 with an aqueous solution containing molybdenum and nickel salts. The molybdenum salt was ammonium heptamolybdate Mo7024(NH4)6.4H20 and the nickel salt was nickel nitrate Ni(N03)2.6H20. After ageing at room temperature in a water-saturated atmosphere, the impregnated extrudates were dried overnight at 120°C then calcined at 550°C for 2 hours in air. The final molybdenum trioxide content was 10.2% by weight and that of nickel oxide NiO was 2.5% by weight.

Catalyst D had an attrition loss percentage of 0.6% of the weight of the catalyst, calculated using the attrition test described in Example 3. EXAMPLE 11: Hydroconversion tests for petroleum residues using catalysts
Al, A2, B, CI, C2 and D
Catalysts Al, A2, B, CI, C2 and D described above were compared in a pilot unit comprising a tube reactor provided with an apparatus for permanently maintaining ebuUation of the catalyst inside the reactor. The pilot unit was representative of an industrial H-Oil ebullating bed residue hydroconversion reactor described in a number of patents, for example US-A-4 521 295 and US-A-4 495 060.
The pilot reactor was charged with 1 litre of catalyst in extrudate form as described above. Once in an ebullating bed mode, the expanded catalyst occupied a volume of 1.5 1 in the reactor.

The unit was operated with the above residue under the following operating conditions:
• pressure = 16 MPa;
• hydrogen flow rate: 600 std 1. H2/I of feed;
• hourly space velocity = 0.3 m of feed/m of reactor/h" .
The temperature was adjusted to about 420-430°C so that all of the catalysts led to 65% by weight conversion of the 550°C'fraction.

The HDS and HDM performances were compared after 2 weeks of test.
The HDS ratio is defined as follows: HDS (wt %) = ((wt % S)feed - (wt % S)test)/(wt % S)feed * 100
The HDM ratio is defined as follows: HDM (wt %) = ((ppm wt Ni+V)feed - (ppm wt Ni+V)test)/ (ppm wt Ni+V)feed * 100.
The degree of conversion is defined as follows: Conversion (wt %) = ((wt % of 550°C+)feed - (wt % of 550°C+)test)/(%wt % of 550°C+)feed * 100.
The stability of the products obtained was evaluated using a "P value Shell" method carried out on the 350°C'fraction of the effluent recovered after the test.
The following table compares the HDS, HDM and P Value Shell values obtained with catalysts Al, A2, B, CI, C2 and D for 65% by weight of conversion of the 550°C* fraction.

It thus appears that the catalysts in the form of extrudates of the present invention can achieve high degrees of conversion of the 550°C"fraction of an oil residue and result in stable products. These catalysts can also significantly hydrodesulphurise and hydrodemetaUise the residue and produce light fractions (diesel, gasoline) which satisfy refiners' specifications. By adjusting the alumina preparation parameters, it is possible to obtain different pore distributions and thus modify the degrees of HDS, HDM and certain petroleum qualities of the effluents from the units such as the stability of the residual 350°C"fraction.

WE CLAIM:
1. A process for hydrotreating a hydrocarbon feed in an ebullating bed, using a catalyst comprising an essentially alumina-based extruded support, essentially constituted by a plurality of juxtaposed agglomerates, optionally at least one catalytic metal or a compound of a catalytic metal from group VIB (group 6 of the new elements periodic table notation) and/or optionally, at least one catalytic metal or a compound of a catalytic metal from group VIII (group comprising nickel, iron and cobalt of the new elements periodic table notation), in which the sum S of the group VIB and VIII metals, expressed as the oxides, is in the range 0.5% to 50% by weight, said extruded support being obtained by a starting alumina forming process comprising: either the following steps:
al or a3: starting with an alumina originating from rapid dehydration of
hydrargillite;
bl or b3; rehydrating the starting alumina; C1 mixing the rehydrated alumina in the presence of an emulsion of at least one hydrocarbon in water, or c3: mixing the rehydrated alumina with a pseudo-boehmite gel, said gel being present in an amount in the range 1% to 30%» by weight with respect to the rehydrated alumina and the gel, so as to obtain a paste;
d1 or d3: extruding the alumina-based paste obtained; el or e3: drying and calcining the extrudates;
fl or f3: carrying out a hydrothermal acid treatment in a confined atmosphere on the calcined extrudates;

gl or g3: drying and calcining the extrudates from said hydrothermal acid
treatment in a confined atmosphere; or the following steps:
a2: starting from an alumina originating from rapid dehydration of
hydrargillite;
b2: forming the alumina into beads in the presence of a pore-forming agent;
c2: ageing the alumina beads obtained;
d2: mixing the beads from step C2 to obtain a paste which is extruded;
e2: drying and calcining the extrudates obtained;
f2: carrying out a hydrothermal acid treatment in a confined atmosphere on the
extrudates from step e2;
g2: drying and calcining the extrudates from step e2, said support having a ratio
of alumina from boehmite decomposition in the range 5% to 70% by weight, a
total pore volume of at least 0.6 cm2/g, and mesopores with an average
diameter in the range 15 to 36 nm, a mesoporous volume V6mm - V100mm of at
least 0.3 cm2/g, a macroporous volume V100mm of at most 0.5 cm2/g, a
microporous volume V0-6mm of at most 0.55 cmVg, and a specific area of at least
120 m3/g., each of said agglomerates being partly in the form of packs of flakes
and partly in the form of needles, said needles being uniformly dispersed both
about the packs of flakes and between the flakes.
2. The process according to claim 1, in which said extruded support is obtained by a preparation process comprising the steps al, bl, cl, dl, el, fl, gl, and in which the alumina from bl comprises at least 3% weight of boehmite.
3. The process according to anyone of claims 1 or 2, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIII and at least one catalytic metal or compound of a catalytic metal from group VIB, and said metals are introduced at least in part separately or simultaneously by impregnation or co-mixing with the support.

4. The process according to anyone of claims 1 to 3, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIB, said metal or compound of a catalytic metal from group VIB is molybdenum or tungsten, and the catalytic metal or the compound of a catalytic metal from group VIII is iron, nickel or cobalt.
5. The process according to anyone of claims 1 to 4, in which said catalyst comprises at least one catalytic metal or compound of a catalytic metal from group VIB, said metal or compound of a catalytic metal from group VIB is molybdenum, and the catalytic metal or the compound of a catalytic metal from group VIII is nickel.
6. The process according to any one of claims 1 to 7, in which the diameter of the alumina extrudates is in the range 0.3 to 1.8 mm.
7. The process according to anyone of claims 1 to 6, for hydrodesulphurization and hydrodemetallation of carbonaceous feedstocks comprising aromatic and/or olefinic, and/or naphtenic, and/or paraffinic compounds, said feedstocks comprising sulphur-, metals, and optionally nitrogen, and/or oxygen.
8. The process according to any one of claims 1 to 7, for hydrodesulphurization of carbonaceous feedstocks comprising aromatic and/or olefinic, and/or naphtenic, and/or paraffinic compounds, said feedstocks comprising sulphur, and optionally nitrogen, and/or oxygen.

9. The process according to any one of claims 1 to 8, that is carried out at a
temperature of 320°C to 470°C, under a partial pressure of hydrogen of 3 MPa
to 30 MPa, at a space velocity of 0.1 to 6 volumes of feed per volume of
catalyst per hour, the ratio of gaseous hydrogen over the liquid hydrocarbon
feed being in the range 100 to 3000 standard cubic metres per cubic metre
(Sm3/m3).
10. A process for hydrotreating a hydrocarbon feed in an ebuUating bed
substantially as herein described with reference to the accompanying drawings.

Documents:

1249-mas-98 abstract.pdf

1249-mas-98 claims duplicate.pdf

1249-mas-98 claims.pdf

1249-mas-98 corrrespondence-others.pdf

1249-mas-98 corrrespondence-po.pdf

1249-mas-98 description (complete) duplicate.pdf

1249-mas-98 description (complete).pdf

1249-mas-98 drawings duplicate.pdf

1249-mas-98 form-19.pdf

1249-mas-98 form-2.pdf

1249-mas-98 form-26.pdf

1249-mas-98 form-4.pdf

1249-mas-98 form-6.pdf

1249-mas-98 others.pdf

1249-mas-98 petition.pdf

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Patent Number

200602

Indian Patent Application Number

1249/MAS/1998

PG Journal Number

27/2006

Publication Date

07-Jul-2006

Grant Date

24-May-2006

Date of Filing

09-Jun-1998

Name of Patentee

M/S. INSTITUT FRANCAIS DU PETROLE

Applicant Address

4 AVENUE DE BOIS PREAU, 92500 RUEIL MALMAISON,

Inventors:

#	Inventor's Name	Inventor's Address
1	HARLE VIRGINIE	34 RUE VICTOR HUGO 60270 GOUVIEUX
2	MOREL FREDERIC	16 RUE DOULLINE 69340, FRANCHEVILLE,
3	COURTY PHILIPPE	58 RUE JB BAUDIN 94800 VILLEJUIF
4	KASZTELANI SLAVIK	27 RUE QUENEAU 92500 RUEILL MALMAISON,
5	KRESSMANN STEPHANE	86 RUE DES FLEURS, 69360 SEREZIN DU RHONE

PCT International Classification Number

B01J 21/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	97/07.150	1997-06-10	France