| Title of Invention | METAL PASSIVATOR ADDITIVE |
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| Abstract | [00046] A process of preparation and composition of an attrition resistant metal passivator additive based on rare earth oxides is disclosed. The metal passivator additive offers higher flexibility against the use of existing cracking catalysts that contain the passivation component as their integral part, as the metal passivator additive can be used only while processing metal laden feeds and the addition can be terminated while processing lighter feeds with negligible metals. Further, the process gives a product having high passivation for metals while meeting required physical properties such as apparent bulk density (ABD) and attrition index (AI). The process comprises preparation of a rare earth component, treating an alumina with a dilute acid to form alumina gel, adding the alumina gel to the rare earth component, optionally adding colloidal silica, preparing a fine slurry of clay, adding the clay slurry to the mixture, spray-drying the mixture, and calcining the spray dried product to obtain the metal passivator additive having adequate ABD and attrition resistance properties. |
| Full Text | METAL PASSIVATOR ADDITIVE FIELD OF INVENTION [0001] The present invention relates to an additive for application in Fluid Catalytic Cracking (FCC) of hydrocarbons. In particular, the invention relates to an additive used in catalytic cracking of heavy oils in petroleum processing industry. BACKGROUND OF THE INVENTION [0002] FCC catalysts used today in cracking process for heavy oils are among the most sophisticated catalysts, having high selectivity towards gasoline range products due to the presence of faujasite type zeolites. Increasing cost of crude is forcing refineries to process opportunity feeds having high carbon residue, nitrogen, aromatics and contaminants such as nickel and vanadium for maintaining decent returns on investment. Of all the contaminants present in feeds, metal contaminants pose the greatest challenge, as some of them permanently cripple the catalytic activity while some metals produce undesired products such as coke and dry gas. Processing such feeds creates increasing demand for catalysts having higher metal tolerance, products termed as Resid Fluid Catalytic Cracking (RFCC) catalyst. Nickel and vanadium are the most prominent among all the metals requiring remedy for their undesired properties. Nickel is well known for dehydrogenation of feed and products under normal FCC operation conditions thereby producing higher coke and dry gas. These effects are predominant with catalysts having higher surface area. Vanadium, unlike nickel, is known for zeolite destroying property and for even worse effects by hopping from aged catalyst particle to fresh catalyst particle while carrying out the destructive action. Vanadium pentoxide, formed during severe regeneration operation, gets converted to vanadic acid which reacts with structural alumina of zeolite and also with structure supporting rare earth species. Thus presence of vanadium in the feed can permanently reduce activity of the FCC catalyst. [0003] U.S. Pat. No. 3,930,987 describes zeolite containing cracking catalysts which are impregnated with a solution of rare earth salts. [0004] For overcoming destructive properties of vanadium and coke forming tendencies of nickel in FCC catalysts, several passivation solutions were discussed in U.S. Pat. Nos. 4,111,845, 4,153,536, and 4,257,919, which were based on antimony, indium or bismuth. [0005] U.S. Pat. No. 4,515,683 discloses a method for passivating vanadium on catalytic cracking catalysts wherein lanthanum is nonionically precipitated on the catalyst prior to ordinary use; however the refiner has no control on metal passivator component as it is an integral part of the main cracking catalyst. [0006] Besides solid metal passivators, there are a number of disclosures on applications of liquid metal passivators. U.S. Pat. No. 4,562,167 refers to liquid metal passivator solution containing Sb and Sn compounds. [0007] U.S. Pat. No. 4,929,583 refers to a process for the catalytic cracking of a vanadium-containing hydrocarbon charge stock by contacting the feed with a catalyst having a weak anion component selected from SrCO.sub.3, SrTiO.sub.3, BaCO.sub.3, Ce.sub.2(CO.sub.3)3 etc. [0008] U.S. Pat. No. 4,938,863 describes a process for making a metal tolerant catalyst with a zeolite in an alumina-free binder or coating, preferably silica, with a vanadium getter additive. [0009] U.S. Pat. No. 5,057,205 refers to a process with an additive for catalytic cracking of high metal content feeds including resids. The catalyst additive comprises of an alkaline earth metal oxide and an alkaline earth metal spinel, preferably a magnesium aluminate spinel. [00010] U.S. Pat. No. 5,071,806 discloses a composition for the catalytic cracking of feeds with high metals, the catalyst comprising a magnesium-containing clay material, a silica-alumina cogel, and zeolite. [00011] U.S. Pat. No. 5,173,174 describes a catalyst matrix comprising bastnaesite and a limited quantity of a large pore boehmite alumina for reducing harmful effects of nickel and vanadium on catalyst activity and selectivity. [00012] U.S. Pat. No. 5,304,299 discloses a cracking catalyst combined with a rare earth, preferably lanthanum-containing catalyst/additive to enhance the cracking activity and selectivity in the presence of nickel and vanadium (Ni and V). The preferred additives comprise of lanthanum, neodymium oxide and/or oxychloride dispersed in a clay/alumina matrix, wherein the alumina is derived from an aluminum hydroxychloride sol. It may be noted that application of aluminum hydroxychloride as a binder containing about 17wt% chlorine, needs additional process while manufacturing such binder based additive. [00013] U.S. Pat. No. 5,384,041 discloses a vanadium trap for use in FCC which comprises a major amount of calcined kaolin clay, free magnesium oxide and an in-situ formed magnesium silicate cement binder. [00014] U.S. Pat. No 5,520,797 and 4,359,379 describe processes for the fluid catalytic cracking of heavy oils rich in Ni and V by withdrawing a portion of ferrite-containing catalyst particles circulating in a fluid catalytic cracking unit, by using a magnetic separator. [00015] U.S. Pat. No. 5,603,823 discloses an additive composition containing Mg-Al oxide spinel with lanthanum and neodymium oxides. [00016] U.S. Pat. No. 5,965,474 describes a catalyst composition for passivating metal contaminants in catalytic cracking of hydrocarbons with ultra-large pore crystalline material as an additive or catalyst composition. The metal passivator is incorporated within the pores of the large pore crystalline material. In a preferred embodiment, the metal passivator is a rare earth metal compound or an alkaline earth metal compound. [00017] U.S. Pat. No. 5,993,645 discloses phosphorus treated cracking catalyst containing soda and phosphate with high tolerance to contaminant metals. [00018] U.S. Pat. Application No. 20070209969 provides a catalyst and a process for cracking heavy feedstocks employing a catalyst with one or more zeolites having controlled silica to alumina ratio. [00019] U.S. Pat. No. 6,673,235 discloses a fluid catalytic cracking catalyst with transitional alumina phase formed within the microspheres to crack resid or resid-containing feeds. [00020] U.S. Pat. No. 6,723,228 discloses an additive in the form of a solution, colloid, emulsion or suspension containing antimony, bismuth and combination of these. [00021] European Pat. No. EP0350280, discloses a metals tolerant FCC catalyst system comprising an admixture of a LZ-210 type molecular sieve component and a bastnaesite type rare earth component dispersed in a large pore matrix containing substantial amounts of a large pore, low surface area alumina. [00022] Between the relative negative roles played by vanadium and nickel metals, the former permanently cripples catalytic activity of a catalyst while the latter increases dry gas and coke and therefore arresting of catalytic activity due to vanadium is a serious issue. It may be seen from literature and patents that the purpose of loading FCC catalyst with rare earth elements is to guard the super cage structure from collapsing when exposed to severe process conditions. It is found that vanadium has high affinity to associate with rare earth metal compounds. As the contaminant vanadium from feed reaches zeolite cages, it instantaneously reacts with the structure supporting rare earth elements thus acting like a precursor to zeolite destruction. From the prior art patents it is seen that rare earth based compounds have been used for neutralizing damaging properties of vanadium contaminant without addressing requirement of composition and physical properties. While in one case bastnaesite has been referred (U.S. Pat. No. 5,173,174), it is known that bastnaesite mineral has impurities such as Ca, Na, Fe, Ti, Mg etc., besides presence of Ce, Nd, Pr as major elements and all elements may not have the required metal passivation characteristics, and hence requires screening of elements for maximum utility. U.S. Pat. No. 5,304,299 refers to a lanthanum containing additive, bonded with aluminum chlorhydrol. Handling of aluminum chlorhydrol requires special metallurgy besides invoking environmental issues. [00023] Thus, development of an effective metal passivator additive requires a process for the preparation of a rare earth component having the right composition, purity along with an effective binder and diluent. OBJECTS OF THE INVENTION [00024] It is an object of the invention to provide an efficient rare earth component suitable for developing a metal passivator additive. [00025] It is another object of the invention to provide an efficient process for preparation of a rare earth component. [00026] It is yet another object of the invention to provide a process for binding a rare earth component with a suitable binder and diluent. [00027] It is still another object of the invention to provide a process for the preparation of a metal passivator additive, by which the developed additive has required physical properties to use along with a host cracking catalyst. [00028] It is still another object of the invention to develop a process for the preparation of a metal passivator additive, application of which reduces deleterious effects of metals such as vanadium and nickel on the host catalyst. [00029] It is yet another object of the invention to provide a process, by which application of additional optional components improves physical properties such as apparent bulk density (ABD) and attrition index (Al) of the metal passivator additive. [00030] It is a further object of the invention to develop a process for the preparation of a metal passivator additive, application of which enhances crystallinity and surface area of a host catalyst. [00031] It is yet another object of the invention to develop a process for preparation of a metal passivator additive, application of which increases activity and selectivity of a host catalyst. [00032] It is yet another object of the invention to develop a process for the preparation of a metal passivator additive with adequate ABD and attrition resistance and metal passivation property, enabling their further use in resid processing while improving performance of a host catalyst. SUMMARY OF THE INVENTION [00033] The present invention relates to a composition and process for preparation of a metal passivator additive based on a rare earth component. The additive offers higher flexibility against the use of existing cracking catalysts containing passivation component as their integral part, as referred in several prior arts. The higher flexibility is offered primarily because the metal passivator additive can be used only while processing metal laden feeds and the addition can be terminated while processing lighter feeds with negligible metals. Further, the process gives a product having high passivation for metals while meeting required physical properties such as apparent bulk density (ABD) and attrition index (Al). The process comprises preparation of a rare earth component, treating an alumina with a dilute acid to form alumina gel, adding the alumina gel to the rare earth component, optionally adding colloidal silica, preparing a fine slurry of clay, adding the clay slurry to the mixture, spray-drying the mixture, and calcining the spray dried product to obtain the metal passivator additive having adequate ABD and attrition resistance properties. DETAILED DESCRIPTION OF THE INVENTION [00034] Accordingly, the present disclosure describes an attrition resistant metal passivator additive suitable for enhancing tolerance of host cracking catalysts towards metals such as vanadium and nickel. The details disclosed below are provided to describe the following embodiments in a manner sufficient to enable a person skilled in the relevant art to make and use the disclosed embodiments. Several of the details described below, however, may not be necessary to practice certain embodiments of the invention. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description. [00035] In one embodiment, the metal passivator additive has adequate ABD and attrition index, which is suitable for use along with host cracking catalysts used for cracking heavy hydrocarbon feeds. [00036] In an embodiment, the metal passivator additive comprises (a) a rare earth component in the range of 1 wt% to 50wt%, (b) alumina in the range of 5 wt% to 35 wt%, and (c) clay in the range of 10 wt% to 50wt%. In another embodiment, the metal passivator additive further comprises of silica in the range of 0 wt% to 30 wt%. In yet another embodiment, the metal passivator additive can have a particle size in the range of 20 to 150 microns with apparent bulk density in the range of 0.70 g/ml to 0.98 g/ml. In another embodiment, the metal passivator additive can have an attrition index in the range of 0.1 to 6 when the rare earth component is present as oxides in the additive. [00037] In an embodiment, the alumina can include pseudoboehmite, gel alumina and bayerite. The alumina can have a residual soda content ranging between 0.001 and 0.1 wt%. The alumina can be acidified using acids including formic acid, acetic acid, nitric acid, hydrochloric acid, and mixtures thereof. [00038] In another embodiment, the silica can be in colloidal form having a mean diameter ranging from 4 nm to 100 nm, and having residual soda content below 0.3 wt%. [00039] In another embodiment, the rare earth component used in the metal passivator additive may comprise of lanthanum oxide in the range of 80-95 wt%, cerium oxide in the range of 5-20 wt%, neodymium oxide in the range of 0.1-5 wt%, and praseodymium oxide in the range of 0.1-5 wt%. [00040] In yet another embodiment, the metal passivator additive can be added to a host cracking catalyst in proportions ranging from 0.1% to 20 wt% during the catalytic cracking of hydrocarbons containing vanadium and nickel as undesirable constituents, and for preventing the adverse effects of vanadium and nickel on the activity of the host cracking catalyst. [00041] Components of the metal passivator additive are further described below on a component by component basis. RARE EARTH COMPONENT [00042] In an embodiment, rare earth component can be developed from rare earth based compounds such as rare earth chlorides, nitrates, oxalates, carbonates, acetates, and formates. In another embodiment, suitable rare earth component can be developed by precipitating rare earth metal hydroxides by reacting mixed rare earth salts with ammonium hydroxide or sodium hydroxide under controlled pH and temperature. The precipitated rare earth metal hydroxides can be aged for a duration of a few minutes to hours and filtered and recovered as a gel. The gel can be washed to minimize ions such as chloride, nitrate, acetate, formate, ammonium and sodium. In another embodiment, the gel, once calcined, can have a surface area ranging from 10 to 150 m2/g with particles size ranging from 8 nm to 3,000 nm. The gel either in hydroxide form or in oxide form can be used either as a pure component or with suitable binders with clay as diluent for preparation of the metal passivator additive. CLAY [00043] In an embodiment, clay can be in finely divided form with particle size below 3 microns. The clay can include kaolinite and halloysite. In another embodiment, the clay has a two-layer structure having alternating sheets of silica in tetrahedral configuration and alumina in octahedral configuration. These sheets are separated with a gap of 7.13 Angstrom units. In another embodiment, dry atmosphere equilibrated clay having moisture content of about 15 wt% can also be used. It is advantageous to use heat processed clay preferably calcined in the temperature range from 250 degree C to 500 degree C, for enhancing dispersion and solid content in final slurry. COLLOIDAL SILICA [00044] In an embodiment, colloidal silica can include aqueous colloidal dispersions of silica particles, stabilized by small quantities of sodium hydroxide or ammonium hydroxide. In another embodiment, the colloidal silica having soda content less than 0.4 wt% can be readily used. Typically, the colloidal silica is stable between pH of about 8.5 and 11. Colloidal silica is commercially available in varying particle size ranging from 7 to 80 nm. . ALUMINA [00045] In an embodiment, pseudoboehmite alumina with soda content less than 0.1 wt% and chemical formula AlOOH (LOI, 22-26 wt%) can be used as a binder for the metal passivator additive because the alumina can be converted into glue by reacting it with acids such as nitric acid, hydrochloric acid, formic acid, or acetic acid. The alumina can have a crystallite size ranging from 3 nm to 30 nm. Glue alumina can be mixed with the rare earth component, clay, and colloidal silica and spray dried for producing the metal passivator additive. In another embodiment, when the spray dried product is calcined, the alumina is transformed into the gamma phase, which holds other ingredients of the metal passivator additive together to form an attrition resistant mass. In yet another embodiment, other species of alumina, such as aluminum trihydrate, bayerite, or gamma alumina can also be used as multifunctional component serving as binder, diluent, and matrix for the metal passivator additive. EXAMPLES The present invention is further explained in the form of following examples. However, these examples should not be construed as limiting the scope of the invention. Example 1 200 g of rare earth chloride (with a specified rare earth metal content of La.sub.2-0.sub.3/REO, 85-90 wt%, Ce0.sub.2/REO, 14-17 wt%, Nd.sub.2-0.sub.3/REO, 0.5-1 wt%, Pr.sub.6-0.sub.ll/REO, 0.2-1 wt%) was dissolved in 1 litre of demineralised (DM) water and kept under stirring. To the rare earth chloride solution was added 12.5% ammonium hydroxide solution under controlled rate in 30 minutes. A viscous slurry of rare earth hydroxide was formed which was aged for 30 minutes and filtered. The filter cake was washed three times to free it from chloride ions by dispersing in cold DM water maintaining solid to water ratio of 1:3 and the cake was oven dried at 110 degree C for 12 hours. Oven dried product showed 35 wt% volatiles (loss on ignition at 950 degree C for 1 hour) and was used as rare earth hydroxide in preparing metal passivator additive of Example 2 and 3 below. The oven dried rare earth hydroxide was calcined at 550 degree C for 1 hour to obtain a rare earth oxide product which showed a surface area of 94 m2/g and a particle size in the range of 100 nm to 1000 nm. The residual soda content was measured and found to be 0.1 wt%. Example 2 767 g of rare earth hydroxide of Example 1 was slurried in 500 g of demineralised water (DM) and kept under stirring. 130 g of pseudoboehmite alumina was slurried in 550 g of DM water and kept under stirring. 29 g of formic acid (85%) was added to the alumina slurry to obtain an alumina gel. The alumina gel was added to the rare earth hydroxide slurry under stirring. 964 g of clay slurry with 41.49 wt% solid content was added to the rare earth hydroxide- alumina slurry under stirring. Final slurry was spray dried to produce microspheres with average particle size of 75 microns. The spray dried product was tested for ABD and attrition index, which were measured respectively as 0.8 g/ml and 9.0. Reference base FCC catalyst (commercial product) and a 5 wt% blend of additive in base were doped with 8000 ppm of vanadium and 3500 ppm of nickel, by Mitchell method {Fluid Catalytic Cracking: Science and Technology (Vol 76), J.S.Magee, M.M Mitchell, Jr. (Elsevier, 1993)), employing vanadium and nickel naphthenates as metal source. Metal impregnated catalysts were oven dried and calcined at 550 degree C. The calcined blends were reduced under hydrogen at 500 degree C and steam deactivated at 788 degree C for three hours with 100% steam. Steam deactivated samples were tested for physical properties along with fresh samples (Table 1). Performance evaluation of steam-deactivated catalysts was carried out with a RFCC feed (refer Table 2 for properties). Performance of the catalysts under identical severity and catalyst/oil ratio is shown by the test data in Table 3. Example 3 153 g of rare earth hydroxide of Example 1 was slurried in 100 g of demineralised water (DM) and kept under stirring. 779 g of pseudoboehmite alumina was slurried in 2150 g of DM water and kept under stirring. 172 g of formic acid (85%) was added to the alumina slurry under stirring to obtain an alumina gel. The alumina gel was added to the rare earth hydroxide slurry under stirring. 3158 g of clay slurry having 41.2 wt% solid content was added under stirring to the rare earth hydroxide-alumina slurry. The final slurry was spray dried to produce microspheres with an average particle size of 75 microns. The spray dried product was processed and evaluated for performance with procedure similar to that followed under example 2 above. The spray dried product was tested for ABD and attrition index, which were measured respectively as 0.74 g/ml and 7.0. The test results for physical properties and performance are shown in Table 1 and Table 4 respectively. Example 4 150.75 g of rare earth oxide of Example 1 was slurried in 150 g of demineralised water (DM) and kept under stirring. 162.8 g of pseudoboehmite alumina was slurried in 710 g of DM water and kept under stirring, while 35.86 g of formic acid (85%) was added to obtain an alumina gel. The gel was added to the rare earth oxide slurry under stirring. 83.3 g of ammonium polysilicate (30 wt% Si02) was added to the rare earth oxide-alumina gel slurry under stirring. Finally, 482 g of clay slurry having a solid content of 41.2 wt% and which contained 0.5 wt% dispersant (Tamol) was added to the rare earth oxide-alumina gel-ammonium polysilicate slurry under stirring. The final slurry was spray dried and the fraction between 20-105 microns with average particle size of 75 microns was separated. The separated fraction was calcined at 550 degree C. The calcined product was tested for ABD and attrition index, which were measured respectively as 0.91 g/ml and 3.1. Final additive was evaluated for performance with a procedure similar to that adopted in the case of Examples 2 and 3, and was found to exhibit a comparable performance with a conversion of 67% and a bottom yield of 12 wt%. Example 5 150.75 g of rare earth oxide of Example 1 was slurried in 150 g of demineralised water (DM) and kept under stirring. 194.65 g of pseudoboehmite alumina was slurried in 853 g of DM water and kept under stirring while 42.88 g of formic acid (85%) was added to obtain an alumina gel. The gel was added to the rare earth oxide slurry under stirring. 432 g of clay slurry having solid content of 46.3 wt% and which contained 0.5 wt% dispersant (Tamol) was added to the rare earth oxide-alumina gel slurry under stirring. The final slurry was spray dried and the fraction between 20-105 microns with an average particle size of 75 microns was separated. The separated fraction was calcined at 550 degree C. The calcined product was tested for ABD and attrition index, which were measured respectively as 0.85 g/ml and 3.0. Table-1. Physical Properties of Base Catalyst and Additive-doped Catalyst Samples (Table Removed) Table-2. Properties of RFCC Feed Used for Testing Performance of Metal Passivator Additive Samples. (Table Removed) Table 3: Performance Evaluation of Steam Deactivated Catalyst Sample of Example 2 (Table Removed) Table 4. Performance Evaluation of Steam Deactivated Catalyst Sample of Example 3 (Table Removed) ADVANTAGES OF THE INVENTION (1) The present invention describes a process for the preparation and use of a metal passivator additive based on rare earth oxides, which offers higher flexibility when compared to the existing cracking catalysts that have the passivation component as their integral part. (2) The additive can be used while processing metal laden feeds and addition can be terminated while processing lighter feeds with negligible metals. (3) Further, the additive provides high passivation for metals while meeting required physical properties such as apparent bulk density (ABD) and attrition index (AI). (4) Further, the additive enhances crystallinity and surface area of a host catalyst during its use. (5) Further, the additive increases activity and selectivity of a host catalyst. WE CLAIM 1. A composition for an attrition resistant metal passivator additive for use during catalytic cracking of hydrocarbons comprising a rare earth component, wherein the rare earth component comprises 80 to 95 wt% of lanthanum oxide, 5 to 20 wt% of cerium oxide, 0.1 to 5 wt% of neodymium oxide, and 0.1 to 5 wt% of praseodymium oxide. 2. The composition of claim 1, wherein the metal passivator additive comprises 1 to 50 wt% of said rare earth component, 5 to 35 wt% of alumina, and 10 to 50 wt% of clay. 3. The composition of claim 1, wherein the metal passivator additive further comprises 0 to 30 wt% of colloidal silica. 4. The composition of claim 1, wherein the rare earth component is either in the form of hydroxides or in the form of oxides, prepared from a mixture of rare earth elements comprising compounds such as rare earth chlorides, nitrates, oxalates, carbonates, acetates, and formates by reacting preferably with dilute ammonium hydroxide or sodium hydroxide solution. 5. The composition of claim 1, wherein the rare earth component has a surface area in the range of 10 m2/g to 150 m2/g and particle size in the range of 8 nm to 3000 nm. 6. The composition of claim 1, wherein the metal passivator additive has an apparent bulk density in the range of 0.70 g/ml to 0.98 g/ml and an attrition index in the range of 0.1 to 6 when the rare earth component is present as oxides in the additive. 7. The composition of claim 1, wherein the metal passivator additive is added to a host cracking catalyst in proportions ranging from 0.1% to 20 wt% during the catalytic cracking of hydrocarbons containing vanadium and nickel as undesirable constituents, and for preventing the adverse effects of vanadium and nickel on the activity of the host cracking catalyst. 8. A process for preparing an attrition resistant metal passivator additive comprising, (a) preparing a rare earth component; (b) treating an alumina with a dilute acid to obtain an alumina binder; (c) adding the alumina binder to the rare earth component to obtain rare earth component-alumina mixture; (d) adding colloidal silica to the rare earth component-alumina mixture to obtain rare earth component-binder mixture; (e) adding milled clay slurry to the rare earth component-binder mixture to obtain an additive precursor slurry; (f) spray-drying the additive precursor slurry; and (g) calcining the spray-dried additive slurry to obtain the metal passivator additive. 9. The process of claim 8, wherein the rare earth component is present either in the form of hydroxides or in the form of oxides and prepared from a mixture of rare earth elements containing compounds such as rare earth chlorides, nitrates, oxalates, carbonates, acetates, and formates by reacting preferably with ammonium hydroxide or sodium hydroxide solution. 10. 11. The process of claim 8, wherein the rare earth component comprises 80 to 95 wt% of lanthanum oxide, 5 to 20 wt% of cerium oxide, 0.1 to 5 wt% of neodymium oxide, and 0.1 to 5 wt% of praseodymium oxide. 12. The process of claim 8, wherein the colloidal silica comprises of silica particles having mean particle size ranging from about 7 nm to 80 nm in either sodium stabilized or ammonium stabilized form. 13. The process of claim 8, wherein the colloidal silica has a maximum soda content of 0.4 wt%. 14. The process of claim 8, wherein the alumina is pseudoboehmite. 15. The process of claim 8, wherein the alumina has a crystallite size ranging from 3 nm to 30 nm. 16. The process of claim 8, wherein the said alumina has a soda content ranging between 0.001 wt% and 0.1 wt%. 17. The process of claim 8, wherein the dilute acid is selected from a group comprising of acetic acid, formic acid, nitric acid, hydrochloric acid, or mixtures thereof. |
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| Patent Number | 269813 | ||||||||||||||||||||||||
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| Indian Patent Application Number | 2391/DEL/2008 | ||||||||||||||||||||||||
| PG Journal Number | 46/2015 | ||||||||||||||||||||||||
| Publication Date | 13-Nov-2015 | ||||||||||||||||||||||||
| Grant Date | 09-Nov-2015 | ||||||||||||||||||||||||
| Date of Filing | 20-Oct-2008 | ||||||||||||||||||||||||
| Name of Patentee | INDIAN OIL CORPORATION LTD | ||||||||||||||||||||||||
| Applicant Address | INDIAN OIL CORPORATION LTD. RESEARCH & DEVELOPMENT CENTER, SECTOR-13, FARIDABAD HARYANA | ||||||||||||||||||||||||
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| PCT International Classification Number | C10G 49/00 | ||||||||||||||||||||||||
| PCT International Application Number | N/A | ||||||||||||||||||||||||
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