Title of Invention

"A METHOD FOR THE PREPARATION OF HYDRODESULFURISATION CATALYST"

Abstract

A method for the preparation of hydrotreating catalyst. The process described is for the preparation of an improved hydrodesulfurisation catalyst for hydrodesulfurisation of gas oil feed stocks. The composition comprises a carrier modified with at least one rare earth metal, on which is supported metal species of group VI B metal comprising either Mo and/or W in an amount of 10-25 % by weight as oxide and a metal of group VIII metal most preferably Ni species in an amount 1-5% by weight as oxide. The catalyst prepared by the described method produces highly dispersed nanostructured active phase after the sulfidation step. This catalyst produces less than 50 ppm sulfur form Indian Gas Oil feed stocks containing about 1% weight sulfur.

Full Text

FIELD OF INVENTION The present inventions relates to a novel process for the preparation of a catalyst for hydrotreating of hydrocarbon feeds particularly hydrodesulfurisation of feeds containing > l%w sulfur. BACKGROUND OF THE INVENTION Due to increasingly stringent sulfur specifications in transportation fuels, removal of sulfur compounds from petroleum feed stocks and products have become very important among the refining processes. Environmental protection agencies world-wide have proposed severe regulations for limiting sulfur content in transport fuels. In diesel, for example, this has already been reduced to 350 to 500 ppm in most of the countries and being brought down to 50 ppm and further down to 10 ppm in some countries. Desulfurisation of diesel streams below 50ppm requires the removal of sulfur compounds which are primarily aromatic heterocyclic compounds namely benzothiophene, dibenzothiophene and its alkyl substituted analogues or its higher homologues. Amongst these, benzothiophene and dibenzothiophene are relatively easily removable sulfur compounds compared to its derivatives especially mono and di alkyl substituted. These sulfur compounds are refractory in nature and pose difficulties in their removal and therefore is the limiting factor for producing low sulfur diesel. Therefore, there is a need for catalysts having improved properties for effective desulfurisation of these refractory sulfur compounds, so that sulfur level of the diesel fuel can be brought down to meet the strictest limits imposed by environmental regulations with minimum or no increase in catalyst volume and operating severity. Hydrotreating is an essential process in the refining of crude petroleum for the removal of sulphur from various petroleum fractions. The catalysts employed for the hydrotreating process, also known as hydrotreating catalyst, are metal oxides which have been sulfided prior to use. The sulfiding of the catalyst are either done insitu in the reactor or by exsitu treatment. Mochida et. al., (Catalysts today, 29, 185(1996)) addressed the deep desulfurisation of diesel fuels, giving importance on both process and catalyst design for handling refractory sulfur which are hardly desulfurized in the conventional HDS process where the process conditions are optimized to obtain product sulfur level of 0.016% weight. A variety of approaches have been reported to efficiently convert the refractory sulfur compounds present in the feed stocks. US Patent no. 5,958,224 discloses that after removal of easy sulfur using conventional hydrodesulfurisation catalysts in the first stage, refractory sulfur can be removed by selective oxidation with transition metal oxide as an oxidizing agent. As an instant of this invention, this prior art uses a peroxo metal complexes in the second stage. Another prior art disclosed in US Patent no. 5,897,768 for handling refractory sulfur using mixed catalyst bed is similar in approach with previous art. The exception being that after the removal of the non refractory sulfur using conventional hydrodesulfurisation catalysts, the product stream containing the unconverted refractory sulfur is to be passed through an "ISOM" unit containing a solid acid catalysts e.g. USY zeolite where refractory sulfur compounds isomerize and disproportionate to easily removable sulfur compounds. Subsequently, this "ISOM" product is recycled to conventional hydrodesulfurisation catalyst bed resulting to low sulfur product. USY Zeolite containing alumina matrix based catalysts has been disclosed in US Patent no. 4,500,645 and JP-V-2-39305 for preparing highly active hydrodesulfurisation catalysts. The matrix used comprises of, in addition to USY zeolite, y alumina, boric acid, zinc oxide and magnesium oxide. The catalyst thus prepared did not show satisfactory performance. The cause of failure is possibly due to average structural similarity of the sulfur compound between the feed stock oil and the product oil as disclosed in US Patent no. 5,686,374. In order to overcome this, inventor of the prior art has modified carrier support by incorporation of zinc oxide and if desired boron compound into the carrier, in addition to USY zeolite. No emphasis has been given on the relative particle size of the components present in the catalyst. US Patent 5484756 discloses the use of a rare earth metal containing refractory alumina carrier for the preparation of hydrodesulfurization catalyst. The catalyst prepared on this support is claimed to have higher desulfurization activities and longer catalyst life than the conventional catalysts. The rare earth element is incorporated either by mixing along with part of metal compounds or during the impregnation of the metal salt solution. The effect of rare earth element in improving the support characteristics or the metal functions has not been clearly identified. A method for preparing an improved hydrodenitrification catalyst have been described in US patent 4530911 in which the Ni or Co and Mo compounds are dissolved in phosphoric acid and hydrogen peroxide solutions respectively. This preparation method is advantageous for preparing very stable metal salt solutions of pH 1.2-2.5. US Patent no. 6,015,485; 6,200,927 and 6,239,054 disclose the necessity of particle size, which is in the nano range. Here methods for preparation of alumina carrier having crystallite size less than 25A on the surface that are considered responsible for higher activity of catalysts are been described. The process described therein being the use of chelating agent, like EDTA and subsequent aging of the support for considerable period of time. Even though the above cited references show a continuous modification and refinement of hydrodesulfurisation catalysts by the expert-knowledgeable in the art for handling refractory sulfur and in some cases desirable activity have been achieved, there is a continuing need for even higher activity catalysts for deep hydrodesulfurisation. One of such processes has been presented in the following invention. SUMMARY OF INVENTION The present invention provides a process for manufacturing a hydrotreating catalyst useful for hydrodesulfurisation of gas oil stream containing refractory sulfur like alkyl substituted condensed ring sulfur, heterocyclic sulfur compound. This said process comprises impregnating a solution containing at least one group VI B metal and one group VIII metal on a preformed extrudates of a rare earth modified y-Alumina carrier. It has been found that catalysts prepared according to the present invention have very high activities for producing very low sulfur diesel. The catalysts prepared according to the invention have surface area about 250 m2/g and pore volume 0.35 ml/g. The catalyst has 1% by weight to about 5% by weight nickel and/or cobalt as oxide and from 10% weight to about 25% by weight molybdenum as oxide. It also consists of 0.1-1.5 moles of phosphorous per moles of molybdenum. The present invention also includes examples of the use of catalyst for effective hydrodesulfurisation of gas oil feed stock containing refractory sulfur compounds. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1. TEM micrographs of the sulfided catalyst with different magnification. Figure 2. GC SCD patterns of feed and product samples. DETAILED DESCRIPTION OF THE INVENTION Base material suitable for preparing the catalyst used in this process of invention are commercially available alumina (A^Os : 73 wt%, Na2O: 0.002 wt%) having surface area ( BET): 300 m2/g and pore volume: 0.90 ml/g. Alternatively the alumina base materials are prepared using cogelations, coprecipitations technique as indicated in US Patent 6,855,653. The alumina precursor is then subjected to treatment for both structural and chemical transformation. The structural modification of the y-alumina is achieved by the treatment of the pseudo-bohemite either with steam and/or with chemicals like EDTA, ammonium hydrogen phosphate, di-ammonium hydrogen phosphate, nitric acid. Most preferably the structural modification is carried out using EDTA either in the presence or absence of steam. On calcinations, the modifying agent will be decomposed and removed from the matrix leaving alumina carrier with different structural features. The chemical modification as disclosed in the invention is carried out by using a rare earth element, most preferably cerium in the presence of an acid solution. The cerium incorporation is done so as to primarily alter only the alumina atoms at the surface and the crystal grain boundaries. Different starting sources of rare earth can be employed. For the use of cerium, various sources like cerium nitrate and cerium ammonium nitrate are preferred. The most preferred source is cerium ammonium nitrate. The concentration of the rare earth in the alumina can range from 0.05 wt%- 2 wt% most preferably in the range 0.1-1.0%. The modification reagent also helps peptizing the alumina so as to shape it to an extrudate of required strength for the finished catalyst. The form of the catalyst may be cylinders, granules tablet or any other shapes and these shapes can be obtained by moulding process such as extrusion and granulation. The diameter of the extrudate is preferably in the range 0.5 to 3.0 mm. The extrudate material may be dried at ambient to 150°C and calcined at a temperature range of about 250 °C to 800°C and more preferably in the range 250°C to 600° C. For the catalyst under the present invention, the metal components supported on the carrier are a combination of Group VIB metal with a group VIII metal, e.g. molybdenum/cobalt, molybdenum/nickel, molybdenum/nickel and cobalt. The process for loading the metals is an incipient impregnation process in which a solution volume just sufficient to fill the pore (wet impregnation) of aluminium hydroxide is used. The volume of the solution for impregnation would have the desired amount of metal loading in the final catalyst. The source of Ni can be nickel nitrate, nickel acetate, nickel sulfate, nickel formate, nickel carbonate, nickel chloride, nickel hydroxide or their mixtures thereof. The source of Mo can be ammonium heptamolybdate or molybdenum oxide or their mixtures thereof. The impregnating solution is prepared by dissolving the Mo salt in aqueous phosphoric acid and then adding desired amounts of Ni salts to the solution. More preferably, the Mo salt is first dissolved in hydrogen peroxide solution, as a solubilizing agent, prior to the addition of phosphoric acid for better solubility of the impregnating solution. The catalyst produced as mentioned above is characterized for the determination of the volume of the pores according to the nitrogen adsorption method as well as measured by the mercury porosimeter. The volume of the pores in catalyst having diameter 150 to 150000A as measured by mercury porosimeter is about 0.35 ml/g. The BET surface area of the catalyst is in the range 200 to 280 m2/g preferably 230 to 250 m2/g. The pore volume as measured by nitrogen adsorption method is also in the range 0.2 to 0.5 ml/g and more preferably 0.3 to 0.4 ml/g. The nitrogen adsorption method and mercury porosimeter which are used as methods for measuring the pore volume of catalysts are performed in accordance with the methods described in P.H. Emmett et.al; catalysis 1,123(1954) (Reinbold publishing co.) The cerium element is believed to be located at the peptized fresh surfaces of the alumina material, thereby to act as an efficient protective component for the alumina surface. This leads to significantly reduced interactions between the support surface and the active metal components to be loaded on the support. The structural modification of the alumina as described in the invention also reduces the metal-support interaction. The reduced interactions between the support surface and the metal elements expected as a result of the induced structural and chemical modification results in the formation of NiMoS and/or CoMoS active sites with very high intrinsic activity during sulfidation of the catalyst. The morphology of MoS2 active phases in the sulfided catalyst was analyzed by Transmission Electron Microscope (TEM.). The lattice resolved TEM micrographs shown in Fig.l indicate the existence of nano sized MoS2 crystallites finely dispersed on the catalyst surface and each crystallite consists of multi-layered MoS2 slabs which can provide large number of edge NiMoS sites, which in turn accounts for the high hydrodesulfurization activity of the catalyst prepared according to the present invention. (Figure Removed) Fig.l. TEM micrographs of the sulfided catalyst with different magnification The invented catalyst is an excellent catalyst for hydrodesulfurisation of gas oil containing total sulfur in the range 8000ppm to 12000ppm and more preferably 8000 to 10000 ppm including refractory sulfur. (The S content was estimated by using a Total S Analyser) Description will be made of a process for hydrodesulfurisation of gas oil by using a catalyst produced according to this invention. Sulfur content in this gas oil is about 8000ppm to 12000ppm by weight. The catalyst which is produced according to this invention is presulfided prior to its use. This presulfidation may be performed in-situ, that is, inside a reactor. The catalyst in the presence of hydrogen containing gas is brought into contact with gas oil doped with sulfur compounds e.g. DMDS about 100 to 400 Nm3/m3 under conditions including a temperature of about 120°C to 300°C, a pressure (total pressure) of about 10 to 50 bar and a liquid hourly space velocity of about 1.5to 3 h" . After this sulfiding treatment, the operation is restarted with sulfur containing diesel feed stock under operation conditions suitable for desulfurisation of the feed stock. The preferred reactor for performing hydrodesulfurisation is a fixed bed tubular reactor. The relative activity of the catalyst was determined by analysing the total sulfur content in the feed and product samples. The catalyst of the present invention is very effective for the removal of refractory sulfur compounds compared to the conventionally prepared catalyst. This is illustrated with the GC-SCD patterns (GC with Sulfur chemiluminescence detector) of the feed and products at different levels of sulfur content in figure 2. The refractory sulfur compounds are substantially removed on deep desulfurization to a sulfur level of (Figure Removed) Fig. 2: GC SCD patterns of fe The S-content of This invention will now be described with reference to examples. Example 1 Preparation of catalyst carrier According to the present invention, alumina powder (343g, 73% AL2O3) was peptized in a stainless steel mulling unit by mixing with approximately 225 ml of dilute nitric acid (1.1 w/v%)solution which also contains ammonium cerium nitrate (4.06 g, 98%). The solution was added slowly over a period of 15 minutes and the wet material was further mulled for 30 minutes. The peptized material was then extruded to 1.2 mm dia trilobe extrudates using a Collins Extruder. The wet extrudates were dried at 120°C for 8 hours and then calcined at 500°C for 1 hour to obtain the catalyst carrier. Preparation of catalyst The catalyst formulation was prepared with metal contents of 3.5%w Ni as NiO, 16.5%w Mo as MoOs and P2Os at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, on the above catalyst carrier. The pore volume impregnation technique was used in which the volume of metal salt solution was adjusted so as to be just sufficient to fill the pores of the alumina carrier. The solution of Mo and Ni compounds was prepared as follows for impregnating 73.5g of the alumina carrier having a pore volume of 0.9 ml/g: Ammonium heptamolybdate (15.74 g, 99%) was mixed with 20 ml of DM water and stirred for 10 minutes. To this solution was slowly added 5 ml of 30% H2O2. H2O2 acts as a solubilizing agent. The solution was stirred and warmed to dissolve the solid completely. To this solution was added molybdenum trioxide (3.82 g, 99.5%) and mixture was then reacted with 10.21g of 88% phosphoric acid. Nickel nitrate hexahydrate (8.34g, 98%) and nickel carbonate (2.59 g, 42.5% Ni) were then added. The solution was heated to approximately 60°C and stirred for complete dissolution of the solid compounds. The solution was then cooled and reacted with diethyl amine (2.16g,99%). The solution was diluted to 66 ml and then poured drop wise over the dehydrated alumina carrier with thorough shaking. After the solution was added completely, the wet extrudates were kept in a closed glass vessel with intermittent shaking for ensuring uniform penetration of the solution. This material was then dried at 120°C for 8 hours to obtain the supported catalysts. This catalyst was further impregnated by incipient wetness method with an aqueous solution of diethylene glycol (5g, 99%) and then again dried at 120°C for 8 hours to obtain catalyst A. Comparative Example 1 The catalyst carrier was prepared in the same manner as in example 1, except that no ammonium cerium nitrate was added in the dilute nitric acid solution used for the peptization of the alumina powder before the extrudate preparation. The catalyst was prepared on above support with metal loading of 3.5%w Ni as NiO and 16.5%w Mo as MoOa, each based on weight of the oxide form of catalyst, by the pore volume impregnation of the alumina carrier with a metal solution prepared by dissolving 20.44g of ammonium molybdate (99%) and 13.90g of nickel nitrate (98%) in dilute ammonia to obtain comparative catalyst Rl. Comparative Example 2 The catalyst carrier was prepared in the same manner as in example 1, except that no ammonium cerium nitrate was added in the dilute nitric acid solution used for the peptization of the alumina powder before the extrudate preparation. The catalyst was prepared on above support with metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoC>3 and P2Os at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as for catalyst A to obtain comparative catalyst R2. Comparative Example 3 The catalyst carrier was prepared in the same manner as in example 1, except that the ammonium cerium nitrate was incorporated by pore volume impregnation of the calcined alumina carrier extrudates with its aqueous solution, instead of adding together with the dilute nitric acid solution during the peptization of alumina powder. The wet extrudates containing ammonium cerium nitrate solution were dried at 120°C and then calcined at 400°C to obtain the modified alumina carrier. The catalyst was prepared on above support with metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoOa and at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as for catalyst A to obtain comparative catalyst R3. Comparative example 4 The catalyst carrier was prepared in the same manner as in example 1. The catalyst was prepared with the metal loading of 3.5%w Ni as NiO and 16.5%w Mo as MoO3 each based on weight of the oxide form of catalyst, by the pore volume impregnation of the alumina carrier with a metal solution prepared by dissolving 20.44g of ammonium molybdate (99%) and 13.90g of nickel nitrate (98%) in dilute ammonia to obtain comparative catalyst R4. Comparative example 5 The catalyst carrier was prepared in the same manner as in example 1. The catalyst was prepared with a metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoOs and P2O5 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as in example 1, except that no diethylene glycol was incorporated in the catalyst after metal loading to obtain comparative catalyst R5. Comparative example 6 The catalyst carrier was prepared in the same manner as in example 1. The catalyst was prepared with a metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoO3 and P2O5 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as in example 1, except that the diethylene glycol was incorporated together with the metal salt solution to obtain comparative catalyst R6. Comparative example 7 The catalyst carrier was prepared in the same manner as in example 1. The metal loading of 3.5%w Ni as NiO and 16.5%w Mo as MoOa, each based on weight of the oxide form of catalyst, is done in the same manner as in example 4, except that 5.0g of diethylene glycol was also incorporated in the dried catalyst obtained after metal loading by the pore volume impregnation with its dilute solution and the resultant wet material was then dried at 120°C for 8 hours to obtain comparative catalyst R7. Example 2 The catalyst carrier was prepared as in the same manner as in Example 1. The catalyst was prepared with the metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoO3 and P2O5 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as in example 1 except that 1.27g of monoethanolamine was added to the metal salt solution in place of diethylene amine to obtain catalyst B. Example 3 The catalyst carrier was prepared as in the same manner as in Example 1. The catalyst was prepared with the metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoO3 and P2O3 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as in example 1 except that 3.50g of EDTA was added to the metal salt solution in place of diethylene amine to obtain catalyst C. Example 4 The catalyst carrier was prepared as in the same manner as in Example 1. The catalyst was prepared with the metal loading of 3.5%w Ni as NiO, 16.5%w Mo as MoO3 and P2O5 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, in the same manner as in example 1 except that 2.29 g of NT A was added to the metal salt solution in place of diethylene amine to obtain catalyst D. Example 5 In order to demonstrate the suitability of the preparation methodology for formulating catalysts with high metal contents such as 4.45%w Ni as NiO, 21%w Mo as MoO3 and P2O5 at a P/Mo molar ratio of 0.8, each based on weight of the oxide form of catalyst, the catalyst E was prepared by a single pore volume impregnation of the modified catalyst carrier prepared in the same manner as in example 1 with metal solution prepared as follows: Ammonium heptamolybdate (20.03 g, 99%) was mixed with 25 mL of DM water and stirred for 10 minutes. To this solution was slowly added 6.4 ml of 30% H2O2. The solution was stirred and warmed to dissolve the solid completely. To this solution was added molybdenum trioxide (4.86 g, 99.5%) and mixture was then reacted with 13 g of 88% phosphoric acid. Nickel nitrate hexahydrate (10.60g, 98%) and nickel carbonate (4.18 g, 42.5% Ni) were then added. The solution was heated to approximately 60°C and stirred for complete dissolution of the solid compounds. The solution was then cooled and reacted with diethyl amine (2.75 g, 99%). Example 6 Activity evaluation of the catalysts The catalytic activity was evaluated using a high pressure, isothermal, fixed bed micro reactor (Xytel, India) operating in a down flow mode. 5 cc of the catalyst is packed after dilution with carborundum in order to minimize channelling and to maintain a plug flow. Prior to the reaction the catalyst was sulfided with a straight run gas oil feed doped with 5% Dimethyl disulfide (DMDS). After the completion of the sulfidation, the feed was cut in to the reactor at the operating conditions. Sample collections were done after achieving a steady state. The HDS activity testing was performed under the conditions shown in Table 1. The feed and product samples were analyzed for the total S content based on oxidative pyre-fluorescence using an ANTEK 7000 Total Sulfur analyzer. The relative activity results of catalyst samples are given in Table 2, 3 and 4. Table 1 Catalyst testing conditions (Table Removed) Table 2 Activity results of comparative examples Rl-7 (Table Removed) Table 3Activity results of catalysts A, B, C, D & E (Table Removed) Table 4 Comparative Product Sulfur of Catalyst A and catalyst Rl (Table Removed) Activity testing conditions and feed properties are: Pressure= 49 bar; LHSV = l.Sh'1, H2/HC = 250Nm3/m3, Sulfur 1.54wt%, Nitrogen = 185ppm, Aromatics = 25.8wt%, T95 Point = 430 (°C) We claim: 1. A process for preparing a hydrotreating catalyst useful for hydrodesulfurisation of gas oil stream containing refractory sulfur like alkyl substituted condensed ring sulfurcompounds, said process comprising of: i. peptizing an alumina powder with an acid solution containing at least one rare earth element as its compound; ii. extruding the peptized material, drying and calcining the extrudates; iii. impregnating the calcined extrudates with an impregnating solution of Group VIII metal compound and Group VIB metal or mixture thereof with 0.1-1.0 moles of a solubilizing agent per mole of Group VIB metal compound and 0.1-1.5 moles of phosphoric acid per mole of Group VIB metal compound; iv. treating the above product with an organic amine compound and drying the composite material at 120°C for 8 hours; and v. impregnating the dried composite material with 1-5 w% of an organic additive selected from diethylene glycol, triethylene glycol, polyethylene glycol and drying at 120°C for 8 hours to obtain the hydrotreating catalyst. 2. The process as claimed in claim 1 wherein said alumina powder is pure gamma alumina or composites of gamma alumina with one selected from the group consisting of silica, zeolite and mixtures thereof. 3. The process as claimed in claim 2 wherein the zeolite used is USY-zeolite. The process as claimed in Claim 1 wherein the impregnating solution consisting of Group VIB metal content of 16- 22 w% as its oxide and Group VIII metal content of 3- 5 w% as its oxide. 4. The process as claimed in Claim 1 wherein the Group VIII metal is selected from Ni or Co. 5. The process as claimed in Claim 1 wherein the Group VIB metal is selected from Mo or W.The process as claimed in Claim 1 wherein the acid solution used for peptizing is selected from a group consisting of formic acid, acetic acid, nitric acid or a mixtures thereof in the concentration range of 0.5- 2 w%. 6. The process as claimed in Claim 1 wherein the acid solution used for peptizing is nitric acid. 7. The process as claimed in claim 1 wherein said rare earth compound is selected from a group consisting of lanthanum nitrate, cerium nitrate, ammonium cerium nitrate and mixtures thereof. 8. The process as claimed in claim 1 wherein the concentration range of rare earth element is 0.1 -5.0 w%. 9. The process as claimed in claim 1 wherein solubilizing agent is selected from a group consisting of H2C>2 and/or ammonium carbonate. 10. The process as claimed in claim 1 wherein the said organic amine compound is selected from the group of compounds containing at least one amino group such as amines, polyamines, amine alcohols, amino acids, EDTA and NTA. 11. The process as claimed in claim 1, the gas oil stream having sulphur 1 to 3w%. 12. The process as claimed in claim 1, after desulfurization the gas oil stream having sulfur less than 50ppm 13. A modified alumina base hydrotreating catalyst useful for hydrodesulfurisation of gas oil stream containing refractory sulfur like alkyl substituted condensed ring sulfur, heterocyclic sulfur compound prepared by process of claim 1 comprising: i) 0.1 to 5.0 w% of rare earth element in its compound; ii) 0.5 - 2.0 w % peptizing agent iii) 1% by weight to about 5% by weight nickel and/or cobalt as oxide; iv) 10% weight to about 25% by weight molybdenum as oxide; v) 0.1-1.5 moles of phosphorous per moles of molybdenum; vi) 0.1-0.5 moles of of Solubilising agent per moles of molybdenum; vii) 0.01-0.3 moles of organic amine compound per moles of molybdenum; and viii) 3-6% wt of the catalyst in the oxide form of glycol

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