Title of Invention	A PROCESS FOR THE PREPARATION OF A TRANSITION METAL CATALYST FOR THE CONVERSION OF NITROBENZENE TO ANILINE
Abstract	A process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements), preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, in A and IV A elements, which is prepared by the process comprising the steps of : (i) precipitating the said metal from its salt solution as metal hydroxycarbonate on the said support containing oxide(s) of the lanthanide elements) at 50°-100°C and aging the precipitated material at 60°-80°C; (ii) cooling the precipitated material and washing the same with deionised water; (iii) drying the washed material at 120°-250°C; (iv) calcining the dried material at 300°-600°C, preferably at 400°-500°C; (v) mixing the calcined material with a suitable binder and a lubricant; (vi) granulating the resulting material to 12-100 mesh size; (vii) tabletting the granulated material to catalyst particles of desired shape and size; (viii) finally calcining the tabletted material at 400°-700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength.

Title of Invention

A PROCESS FOR THE PREPARATION OF A TRANSITION METAL CATALYST FOR THE CONVERSION OF NITROBENZENE TO ANILINE

Abstract

A process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements), preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, in A and IV A elements, which is prepared by the process comprising the steps of : (i) precipitating the said metal from its salt solution as metal hydroxycarbonate on the said support containing oxide(s) of the lanthanide elements) at 50°-100°C and aging the precipitated material at 60°-80°C; (ii) cooling the precipitated material and washing the same with deionised water; (iii) drying the washed material at 120°-250°C; (iv) calcining the dried material at 300°-600°C, preferably at 400°-500°C; (v) mixing the calcined material with a suitable binder and a lubricant; (vi) granulating the resulting material to 12-100 mesh size; (vii) tabletting the granulated material to catalyst particles of desired shape and size; (viii) finally calcining the tabletted material at 400°-700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength.

Full Text	FORM - 2 THE PATENTS ACT, 1970 COMPLETE SPECIFICATION SECTION 10 TITLE A PROCESS FOR THE PREPARATION OF A TRANSITION METAL CATALYST FOR THE CONVERSION OF NITROBENZENE TO ANILINE 1) HINDUSTAN ORGANIC CHEMICALS LIMITED, A GOVT. OF INDIA ENTERPRISE, RASAYANI, DIST. RAIGAD, PIN- 410 207, MAHARASHTRA, INDIA 2) SUD-CHEMIE INDIA PRIVATE LIMITED, AN INDIAN COMPANY, EDAYAR INDUSTRIAL DEVELOPMENT AREA, P.O. BINANIPURAM, PIN-683 502, KERALA, INDIA APPLICANTS INVENTORS U/S 28 (2) 1. DR, DAS JAGAT KUMAR 2. JOSHI DHANANJAY VrNAYAK, 3. RAMKRISHNA MUDDARANGAIAH 4. DR. NITTALA VENKATA RAMA RAO AND 1. LALLJEE ARSHIA ALTAF 2. DHADALLA ABDULRAUF PEERMOHAMED 3. DR. KARUKAPADATH KUNJIMOIDEEN ABDUL RASHID 4. DR. RUGMINI SREEKALA 5. PHILIP PRAVEEN } } HINDUSTAN ORGANIC CHEMICALS LIMITED, A GOVT. OF INDIA ENTERPRISE, RASAYANI, DIST. RAIGAD, PIN- 410 207, MAHARASHTRA, INDIA. SUD-CHEMIE INDIA PRIVATE LIMITED, AN INDIAN COMPANY, EDAYAR INDUSTRIAL DEVELOPMENT AREA, P.O. BINANIPURAM, PIN-683 502, KERALA, INDIA The following Specification particularly describes and ascertains the nature of this invention and the manner in GRANTED 18-8-2003 which it is to be performed :- The invention relates to a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase at about 150° to 230°C, preferably at 160° to 220°C. The catalyst of the present invention contains oxide of the said metal promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of Group II A, HI A and IV A elements in definite proportions. The incorporation of the aluminate of an alkaline earth metal in the system imparts proper mechanical strength to the catalyst particles of preferred shape and size, which makes the said particles suitable for utilization in fixed bed reactors for commercial applications. FIELD OF THE INVENTION This invention relates to a process for the preparation of a supported transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase in fixed bed reactors. The incorporation of the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series, improves the activity and selectivity of the said catalyst. The catalyst of the present invention exhibits very high conversion of nitrobenzene and can be used conveniently in the fixed bed reactors for the production of aniline. PRIOR ART Aniline is commercially produced by catalytic hydrogenation of nitrobenzene, which is conveniently carried out in vapour phase in the fixed bed multitubular reactors. The commercial catalyst used for the manufacture of aniline is known in the art as copper chromite. The copper chromite catalyst is considered as a binary system of CuO-Cr2O3 in the oxidized state and is like a supported metal catalyst in the reduced state [D.K. Ghorai, D. Datta, N.C. Ganguli and S.P. Sen, Fertilizer Technology, 18, 146 (1981)]. The copper chromite catalyst is reduced in-situ by using hydrogen and nitrogen mixtures with varying amounts of hydrogen (about 1 to 15% by volume) at about 180° - 260°C, which leads to the formation of copper sites uniformly distributed on the catalyst surface (J.K. Das and M. Sriram, Chemical Industry Digest, Fourth Quarter, 1990]. This elemental copper is the active ingredient in the commercial catalysts for the hydrogenation of nitro-aromatic hydrocarbons [A.K. Banerjee and D. Datta, Fertilizer Technology, 18,131 (1981)]. Recently studies are focused on the development of chromium-free catalysts, particularly in view of the problems related to handling and disposal of chromia-based catalysts. In a recent embodiment, the U.S. Patent No.6,049,008 describes a process for hydrogenating aldehydes, ketones, carboxylic acids, carboxylic acid esters and nitro-aromatic compounds, which comprises contacting one or more of the said materials under catalytic hydrogenation conditions with a shaped catalyst composition. The said catalyst composition consists of (i) at least one metal selected from the group consisting of copper, nickel, manganese, zinc, and cobalt; (ii) calcium silicate; and (iii) at least one clay material. The shaped particles are extrudates. This catalyst exhibits nitrobenzene conversion of 99.5 - 99.6% wt at 198°-200°C. The catalyst of the present invention exhibits very high conversion of nitrobenzene (almost 100%) under the process conditions of commercial plants. The unreacted nitrobenzene in the hydrogenated mass is about 0.20 to 200 parts per million (ppm), which is negligibly small. The catalyst of the present invention is also highly selective for the conversion of nitrobenzene to aniline. DESCRIPTION OF THE INVENTION The present invention relates to a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase in fixed bed reactors. According to this invention, the catalyst contains oxide of the said metal and is promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series. In the practice of the present invention, a combination of the oxides of two elements of the lanthanide series as promoters, is preferred for better activity and selectivity of the catalyst. The said catalyst is supported on a composite support material comprising the oxides of Group II A, in A and IV a elements in definite proportions. The aluminate of an alkaline earth metal is used as a binder to impart proper mechanical strength to the catalyst particles. The shape of the catalyst particles of the present invention is cylindrical tablet of length, 3 to 6 mm, preferably 4.7 to 5.2 mm and diameter, 3 to 6 mm, preferably 4.7 to 5.2 mm. We herein disclose a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase, which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, HI A and IV A elements, which is prepared by the process comprising the steps of: (i) precipitating the said metal from its salt solution as metal hydroxy carbonate on the said support containing the oxide(s) of lanthanide element(s) at about 50°-100°C and aging the precipitated material at about 60°-80°C; (ii) cooling the precipitated material and washing the same with deionised water; (iii) drying the washed material at about 120°-250°C; (iv) calcining the dried material at about 300°-600°C, preferably at 400°-500°C; (v) mixing the calcined material with a suitable binder and a lubricant; (vi) granulating the resulting material to about 12- 100 mesh size; (vii) tabletting the granulated material to catalyst particles of desired shape and size; (viii) finally calcining the tabletted material at about 400° to 700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength. The transition metal salt used in the present invention is copper nitrate or copper ammine carbonate. The elements of the lanthanide series are lanthanum and cerium, the oxides of which are used in the mole ratio of 1:1. The Group II A, III A and IV A elements are calcium, aluminium and silicon respectively. The composite support material contains oxides of the said elements having mole ratio of calcium oxide to alumina to silica of 2 to 4:1:2 to 5. The precipitation is carried out by adding metal nitrate solution to the solution of an alkali metal carbonate in the pH range of about 7 to 10 or by adding the solution of the alkali metal carbonate to metal nitrate solution in the pH range of about 2 to 7. In the practice of this invention, sodium carbonate is used as the preferred alkali metal carbonate. The addition of copper nitrate solution to the alkali metal carbonate or vice versa at a controlled slow rate with vigorous agitation is carried out to ensure that the precipitate is not getting agglomerated. Copper nitrate solution is prepared by dissolving the said nitrate in deionised water. Copper solution which is taken for precipitation contains between 30 and 100 grams of copper per litre, preferably between 70 and 90 grams per litre. Sodium carbonate solution is prepared by dissolving the said salt in deionised water. Sodium carbonate solution used for precipitation contains about 50-250 grams per litre, preferably 100-200 grams per litre of the said carbonate. According to this invention, a mixture of copper nitrate solution and the said promoters, is added to a well-agitated solution of the alkali metal containing the said support material. Alternatively, the alkali metal solution and the mixture of copper nitrate solution, the said promoters and support material, are simultaneously added to boiling water. The pH of the mixture during precipitation is maintained at about 6 to 8. The temperature is maintained in the range of about 50° to 100°C, preferably at 60° - 80°C. The catalyst can also be prepared by decomposing copper ammine carbonate in presence of the said promoters and support material. A solution of the said ammine carbonate is agitated with the said promoters and support material. The mixture is added dropwise to boiling water to decompose the said ammine carbonate to give copper hydroxycarbonate on the said support incorporating the promoter oxides uniformly in the system. There are several advantages for the preparation of catalyst from metal ammine carbonate solution. Since alkali metal carbonate is not involved in the preparation of catalyst, the extent of washing of the precipitate can be minimized. Impact of using metal nitrate solution on environment can also be prevented. Further processing of the precursor obtained by this method is carried out in a similar manner as described herein for the preparation of catalyst from metal nitrate solution. The precipitation is carried out over a period of 2 to 5 hours. The precipitated material is aged for a period of about 1-3 hours to improve crystallinity. The aging is carried out in the temperature range of about 60° to 80°C. The slurry is then cooled to about 30°-35°C. Since the precipitation is carried out with excess of alkali metal carbonate than the stoichiometric requirement, the precipitate is to be thoroughly washed with deionised water to remove the alkali metal ions. Even the trace amount of alkali metal present in the catalyst is likely to reduce the dispersion of active phase, which reduces the performance of the catalyst remarkably. Therefore, the aged precipitate is washed with dionised water for about 3 to 10 times by filtration and resulurrying of the precipitated mass to remove the alkali metal ions. The washed precipitate, which contains metal hydroxy carbonate and promoters on the composite support material, is decomposed to give metal oxide on the support containing promoters. Drying and calcination of the washed precipitate are carried out in a precisely controlled slow heating rate to achieve maximum dispersion of active phase on the support. Controlled drying and calcination can also lead to a product with high surface area. The washed precipitate is dried at about 120°-250°C for about 3 to 12 hours and calcined at a temperature of about 300°C to 600°C, preferably at 400°-500°C for about 2 to 6 hours. The programmed heating is carried out at a controlled rate of about 30° to 100°C per hour, preferably 40° to 60°C per hour. The aluminate of an alkaline earth metal is used as a binder and graphite is used as the lubricant. In the practice of this invention, the preferred alkaline earth metal used is calcium. The calcined mass is mixed with the said binder and the lubricant, and is ball-milled. Then the sample is granulated to 12 -100 mesh size. Finally, the granulated sample is tabletted to form the cylindrical particles. The tabletted material is calcined at a temperature of about 400°-700°C, preferably at 450°C-550°C for about 2 to 6 hours. The catalyst according to the present invention, is characterized by the copper oxide content of about 40 to 65% by weight and copper dispersion of about 20 to 30%. The atomic ratio of copper to lanthanum to cerium is from about 45:2:1 to about 145:2:1. Surface area of the catalyst prepared by the method of the present invention is about 50 to 80 m2/g with a total pore volume of about 0.15 to 0.35 ml/g. The side crushing strength of the catalyst particle is about 15 to 30 kg. The catalyst is evaluated in the fixed bed in a mild steel/stainless steel single tube reactor, which is heated electrically by using a vertical tube furnace in which the reactor is fixed co-axially. The temperature of the tube furnace is controlled properly by using an automatic temperature controller. Alternatively, the catalyst is evaluated in the fixed bed in mild steel/stainless steel multitubular reactor which consists of about 2000 to 3000 tubes, is heated by circulating hot oil through a vertical jacket in which the said reactor is fixed co-axially. The volume of the catalyst used for evaluation in the said reactor is about 30 to 1290 ml. A desired volume of the catalyst is charged in the said reactor and is reduced by passing a mixture of nitrogen and hydrogen (with varying amounts of the latter from about 0.01 to 20% by volume) through the catalyst bed at a temperature of about 180°-220°C and a space velocity of about 1000 to 2200 hr" for about 8 to 168 hours. The catalyst is then evaluated in-situ by passing a mixture of nitrobenzene vapour and hydrogen through the catalyst bed at a temperature of about 150° to 230°C, preferably at 160° to 220°C and at a mole ratio (nitrobenzene: hydrogen) of 1:30 to 1:15, and a space velocity of about 1000-2000 hr . Nitrobenzene containing about 500-800 ppm of m-dinitrobenzene, produced by M/s. Hindustan Organic Chemicals Limited, Rasayani has been used as feed stock for evaluation of the catalyst. Under the experimental condition employed, the catalyst of the present invention exhibits almost complete conversion of nitrobenzene which is indicated by the negligibly small amount of unreacted nitrobenzene (about 0.2-200 ppm) in the hydrogenated mass. The catalyst gives about 98.0-99.9% aniline and 0.10-2.0 % N- phyenylcyclohexylamine (PCHA). The properties of the catalyst viz., chemical composition, surface area, pore volume and mechanical strength (side crushing strength) are determined by known methods. Examples I to IV are given for the preparation of catalyst and Examples V to VIII are given for the evaluation of the catalyst for the conversion of nitrobenzene to aniline in the vapour phase. The invention is described further with reference to the following examples. The examples are given only for illustration which do not limit the scope of this invention. EXAMPLE-I A mixture of copper nitrate solution (35 litres, 7.2% Cu) and oxides of lanthanide elements (0.42 kg which contains La2O3 and Ce02 in the mole ratio of 1:1) is added dropwise to a solution of sodium carbonate (29 litres, 15%) containing the support material (1.1 kg material which contains CaO, alumina and silica in the mole ratio of 2:1:2) with vigorous agitation. The temperature is maintained at 60°-80°C. The pH of the slurry is 7.0. The precipitation is carried out over a period of 3 hours. The precipitate is aged at 60°-80°C for 1 hour and is cooled and washed five times by filtration and reslurrying the precipitate. The washed precipitate is dried at 120°C for 12 hours and is heated at a programmed slow heating rate of 40°C per hour upto 450°C and is kept at 450°C for 6 hour to complete the calcination. The powder catalyst sample thus obtained has got a bulk density of 1.1 kg/litre and loss on ignition at 540°C is 5% by weight. The said powder is ball-milled for 1 hour after mixing with the said binder (0.350 kg) and the said lubricant (0.050 kg). Then mix mulling of the above material is done with deionised water for 30 minutes and is dried at 150°C for 4 hours. The dried sample is granulated to 12-100 mesh size and finally tabletted to cylindrical shape of 4.7 mm x 4.7 mm size, and calcined at 450°C for 4 hours. The finished product exhibits a surface area of 65.0 m2/g with a pore volume of 0.15 ml/g. The catalyst contains 47.93% copper having atomic ratio of copper to lanthanum to cerium of 47:2:1. The side crushing strength of the catalyst pellets is 26.0 kg and it has a bulk density of 1.5 kg/1. EXAMPLE-II Copper ammine carbonate solution (26 litres, Cu, 9.8%) is agitated well with 1.2 kg of the support material (containing CaO, alumina and silica in the mole ratio of 4:1:3) and 0.25 kg of rare earth oxides (La2O3 and CeO2) in the mole ratio of 1:1). The mixture is added dropwise to boiling water to decompose the said ammine carbonate. The temperature during decomposition is maintained at 80°-100°C. The decomposition is carried out over a period of three hours. The mixture is cooled to 30°-35°C. The precipitated material is washed twice by filtration and reslurrying, and is dried at 120°C for 8 hours. It is calcined in a similar manner as described in Example -1. The powder catalyst sample has got a bulk density of 0.9kg/litre and loss on ignition at 540°C is 4.5% by weight. The above sample is mixed with 0.38 kg of the said binder and 0.050 kg of the said lubricant, and is processed further to the finished product as described in Example-I. The finished product exhibits a surface area of 63 m /g with a pore volume of 0.17 ml/g. The catalyst contains 47.37% copper having a mole ratio of copper to lanthanum to cerium of 75:2:1. The bulk density of the catalyst is 1.4 kg/litre. It exhibits a side crushing strength of 28.0 kg. EXAMPLE-III Copper nitrate solution (35 litres, 7.2% Cu), rare earth oxides (0.25kg which contains lanthana and ceria in the mole ratio of 1:1) and the support material (1.6 kg containing CaO, AI2O3 and SiO2 in the mole ratio of 2:1:2) are mixed and agitated well. Sodium carbonate solution (29 litres, 15%) and the above mixture are added simultaneously to boiling water under agitation maintaining the pH in the range of 6-8. The temperature is maintained at 60°-80°C. The precipitate is aged for 2 hours and is cooled and filtered. It is washed five times by filtration and reslurrying, and is dried at 250°C for 3 hours. The dry powder is calcined at 450°C for 3 hours. The dry powder which has got a bulk density of 0.98 kg/litre, exhibits 13.0% loss on ignition at 540°C. The above powder is mixed with 0.30 kg of the said binder and 0.050 kg of the said lubricant, and is processed further to finished product as described in Example-I. The finished product exhibits a surface area of 58 m2/g and a pore volume of 0.21 ml/g. The copper content in the catalyst is 48.73%. The atomic ratio of copper to lanthanum to cerium is 77:2:1. The catalyst which exhibits a side crushing strength of 18 kg, has a bulk density of 1.4 kg/litre. EXAMPLE-IV In this example, the catalyst is prepared by a similar method as described in Example-III except the volumes/quantities of raw materials used in the experiment. The volumes of copper nitrate and sodium carbonate solutions are 3500 litres and 2900 litres respectively. The quantity of rare earth oxides (La2O3 and CeO2 in the mole ratio of 1:1) is 25 kg. The quantities of the support material, the binder and the lubricant are 160 kg, 30 kg and 5 kg respectively. The catalyst exhibits a surface area of 55 m2/g and a pore volume of 0.20 ml/g. The copper content in the catalyst is 49.37%. The atomic ratio of copper to lanthanum to cerium is 97:2:1. The bulk density of the catalyst is 1.3 kg/1. The side crushing strength of the catalyst pellet is 14.7 kg. EXAMPLE-V The catalyst of Example-I (30ml) charged in a stainless steel single tube reactor was reduced at 200°-215°C by passing a mixture of nitrogen and hydrogen with varying amounts of the latter from 1 to 10% by volume at a space velocity of 1090-1110 hr" for 10 hours. The hydrogenation of nitrobenzene to aniline was carried out in-situ by passing a mixture of nitrobenzene vapour and hydrogen at a temperature of 160°-l65°C, a space velocity of 1146 hr" and a mole ratio (nitrobenzene : hydrogen) of 1:20. The mixture of nitrobenzene vapour and hydrogen was passed through the catalyst bed for 20 hours under the reaction conditions as hereinbefore described. A sample of the hydrogenated mass, collected after 20 hours, was analyzed. The results of analysis are as follows : Aniline : 98.6 % PCHA : 1.2 % Unreacted nitrobenzene : 200 ppm EXAMPLE-VI This experiment was carried out using the catalyst of Example - II in a similar manner under similar experimental conditions except the duration of passing the mixture of nitrobenzene vapour and hydrogen through the catalyst bed. In this experiment, the said mixture was passed through the catalyst bed for 16 hours. A sample of the hydrogenated mass collected after 16 hours, was analyzed. The results of analysis are as follows: Aniline : 98.04 % PCHA : 1.89 % Unreacted nitrobenzene : 10 ppm EXAMPLE -VII This experiment was carried out using the catalyst of Example - III in a similar manner under similar experimental conditions as described in Example - V. The results of analysis of the hydrogenated mass are as follows: Aniline : 99.35 % PCHA : 0.24 % Unreacted nitrobenzene : 1.85 ppm EXAMPLE - Vffl The experiment was carried out in a mild steel multitubular reactor using the catalyst of Example-IV. The volume of the catalyst charged in a tube of the said reactor is 1270 ml. The catalyst is reduced at 191°-219°C by passing a mixture of nitrogen and hydrogen (with varying amounts of the latter from 0.01 to 5.30% by volume) through the catalyst bed at a space velocity of 2080-2140 hr"1 for 120 hours. The catalyst was then evaluated in-situ by passing a mixture of nitrobenzene vapour and hydrogen through the catalyst bed at a temperature of 155°-159°C, a space velocity of 1890-1945 hr" and a mole ratio (nitrobenzene : hydrogen) of 1:28.46 to 29.34. A sample of the hydrogenated mass collected after 157 hours (from start-up of the reactor) was analyzed. The results of analysis are given below: Aniline : 99.6 % PCHA : 0.4 % Unreacted nitrobenzene : 0.41 ppm We claim A process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements), preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, in A and IV A elements, which is prepared by the process comprising the steps of : (i) precipitating the said metal from its salt solution as metal hydroxycarbonate on the said support containing oxide(s) of the lanthanide elements) at 50°-100°C and aging the precipitated material at 60°-80°C; (ii) cooling the precipitated material and washing the same with deionised water; (iii) drying the washed material at 120°-250°C; (iv) calcining the dried material at 300°-600°C, preferably at 400°-500°C; (v) mixing the calcined material with a suitable binder and a lubricant; (vi) granulating the resulting material to 12-100 mesh size; (vii) tabletting the granulated material to catalyst particles of desired shape and size; (viii) finally calcining the tabletted material at 400°-700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength. 2. A process as claimed in claim 1, wherein the transition metal is copper. 3. A process as claimed in claim 1, wherein the lanthanide elements are lanthanum and cerium. 4. A process as claimed in claim 1, wherein the Group II A, HI A and IV A elements are calcium, aluminium and silicon respectively. 5. A process as claimed in claim 1, wherein the metal salt used in step (i) is copper nitrate or copper arnmine carbonate. 6. A process as claimed in claim 1, wherein in step (i), the precipitation is carried out over a period of 2 to 5 hours. 7. A process as claimed in claim 1, wherein in step (i), the precipitated material is aged for a period of 1 to 3 hour(s). 8. A process as claimed in claim 1, wherein in step (ii), the precipitated material is cooled to 30° to 35°C. 9. A process as claimed in claim 1, wherein in step (ii), the washing is carried out with deionised water for 3 to 10 times by filtration and reslurrying of the precipitated mass. 10. A process as claimed in claim 1, wherein in step (iii), the drying is carried out for 3 to 12 hours. 11. A process as claimed in claim 1, wherein in step (iv), the calcination is carried out for 2 to 6 hours. 12. A process as claimed in claim 1, wherein in step (v), the binder and the lubricant used are calcium aluminate and graphite respectively. 13. A process as claimed in claim 1, wherein in step (vii), the desired length of the said tablet is about 3 to 6 mm, preferably 4.7 to 5.2 mm and the desired diameter is about 3 to 6 mm, preferably 4.7 to 5.2 mm, 14. A process as claimed in claim 1, wherein in step (viii), the calcination of the tabletted material is carried out for 2 to 6 hours. 15. A process as claimed in claims 1 to 14, wherein the side crushing strength of the catalyst particles is 15 to 30 kg. 16. A process as claimed in claims 1 to 15, wherein the surface area and the pore volume of the finished product are 50-80 m2/g and 0.15-0.35 ml/g respectively. 17. A process as claimed in claims 1 to 16, wherein the atomic ratio of copper to lanthanum to cerium is from 45 : 2 :1 to 145 : 2 : 1.

Full Text

FORM - 2 THE PATENTS ACT, 1970
COMPLETE SPECIFICATION
SECTION 10

TITLE

A PROCESS FOR THE PREPARATION OF A TRANSITION METAL CATALYST FOR THE CONVERSION OF NITROBENZENE TO ANILINE

1) HINDUSTAN ORGANIC CHEMICALS LIMITED, A GOVT. OF INDIA ENTERPRISE, RASAYANI, DIST. RAIGAD, PIN- 410 207, MAHARASHTRA, INDIA
2) SUD-CHEMIE INDIA PRIVATE LIMITED, AN INDIAN COMPANY,
EDAYAR INDUSTRIAL DEVELOPMENT AREA, P.O. BINANIPURAM, PIN-683 502, KERALA, INDIA
APPLICANTS
INVENTORS U/S 28 (2)
1. DR, DAS JAGAT KUMAR
2. JOSHI DHANANJAY VrNAYAK,
3. RAMKRISHNA MUDDARANGAIAH
4. DR. NITTALA VENKATA RAMA RAO
AND
1. LALLJEE ARSHIA ALTAF
2. DHADALLA ABDULRAUF PEERMOHAMED
3. DR. KARUKAPADATH KUNJIMOIDEEN ABDUL RASHID
4. DR. RUGMINI SREEKALA
5. PHILIP PRAVEEN

} }

HINDUSTAN ORGANIC CHEMICALS LIMITED, A GOVT. OF INDIA ENTERPRISE, RASAYANI, DIST. RAIGAD, PIN- 410 207, MAHARASHTRA, INDIA.
SUD-CHEMIE INDIA PRIVATE LIMITED,
AN INDIAN COMPANY,
EDAYAR INDUSTRIAL DEVELOPMENT AREA,
P.O. BINANIPURAM, PIN-683 502,
KERALA, INDIA

The following Specification particularly describes and ascertains the nature of this invention and the manner in
GRANTED
18-8-2003
which it is to be performed :-

The invention relates to a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase at about 150° to 230°C, preferably at 160° to 220°C. The catalyst of the present invention contains oxide of the said metal promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of Group II A, HI A and IV A elements in definite proportions. The incorporation of the aluminate of an alkaline earth metal in the system imparts proper mechanical strength to the catalyst particles of preferred shape and size, which makes the said particles suitable for utilization in fixed bed reactors for commercial applications.
FIELD OF THE INVENTION
This invention relates to a process for the preparation of a supported transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase in fixed bed reactors. The incorporation of the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series, improves the activity and selectivity of the said catalyst. The catalyst of the present invention exhibits very high conversion of nitrobenzene and can be used conveniently in the fixed bed reactors for the production of aniline.
PRIOR ART
Aniline is commercially produced by catalytic hydrogenation of nitrobenzene, which is conveniently carried out in vapour phase in the fixed bed multitubular reactors. The commercial catalyst used for the manufacture of aniline is known in the art as copper chromite. The copper chromite catalyst is considered as a binary system of CuO-Cr2O3 in the oxidized state and is like a supported metal catalyst in the reduced state [D.K. Ghorai, D. Datta, N.C. Ganguli and S.P. Sen, Fertilizer Technology, 18, 146 (1981)]. The copper chromite catalyst is reduced in-situ by using hydrogen and nitrogen mixtures with varying amounts of hydrogen (about 1 to 15% by volume) at about 180° - 260°C, which leads to the formation of copper sites uniformly distributed on the catalyst surface (J.K. Das and M. Sriram, Chemical Industry Digest, Fourth Quarter, 1990].

This elemental copper is the active ingredient in the commercial catalysts for the hydrogenation of nitro-aromatic hydrocarbons [A.K. Banerjee and D. Datta, Fertilizer Technology, 18,131 (1981)]. Recently studies are focused on the development of chromium-free catalysts, particularly in view of the problems related to handling and disposal of chromia-based catalysts.
In a recent embodiment, the U.S. Patent No.6,049,008 describes a process for hydrogenating aldehydes, ketones, carboxylic acids, carboxylic acid esters and nitro-aromatic compounds, which comprises contacting one or more of the said materials under catalytic hydrogenation conditions with a shaped catalyst composition. The said catalyst composition consists of (i) at least one metal selected from the group consisting of copper, nickel, manganese, zinc, and cobalt; (ii) calcium silicate; and (iii) at least one clay material. The shaped particles are extrudates. This catalyst exhibits nitrobenzene conversion of 99.5 - 99.6% wt at 198°-200°C.
The catalyst of the present invention exhibits very high conversion of nitrobenzene (almost 100%) under the process conditions of commercial plants. The unreacted nitrobenzene in the hydrogenated mass is about 0.20 to 200 parts per million (ppm), which is negligibly small. The catalyst of the present invention is also highly selective for the conversion of nitrobenzene to aniline.
DESCRIPTION OF THE INVENTION
The present invention relates to a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase in fixed bed reactors. According to this invention, the catalyst contains oxide of the said metal and is promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series. In the practice of the present invention, a combination of the oxides of two elements of the lanthanide series as promoters, is preferred for better activity and selectivity of the catalyst.

The said catalyst is supported on a composite support material comprising the oxides of Group II A, in A and IV a elements in definite proportions.
The aluminate of an alkaline earth metal is used as a binder to impart proper mechanical strength to the catalyst particles. The shape of the catalyst particles of the present invention is cylindrical tablet of length, 3 to 6 mm, preferably 4.7 to 5.2 mm and diameter, 3 to 6 mm, preferably 4.7 to 5.2 mm.
We herein disclose a process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase, which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements, preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, HI A and IV A elements, which is prepared by the process comprising the steps of:
(i) precipitating the said metal from its salt solution as metal hydroxy carbonate on the said support containing the oxide(s) of lanthanide element(s) at about 50°-100°C and aging the precipitated material at about 60°-80°C;
(ii) cooling the precipitated material and washing the same with deionised water;
(iii) drying the washed material at about 120°-250°C;
(iv) calcining the dried material at about 300°-600°C, preferably at 400°-500°C;
(v) mixing the calcined material with a suitable binder and a lubricant;
(vi) granulating the resulting material to about 12- 100 mesh size;
(vii) tabletting the granulated material to catalyst particles of desired shape and size;
(viii) finally calcining the tabletted material at about 400° to 700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength.
The transition metal salt used in the present invention is copper nitrate or copper ammine carbonate. The elements of the lanthanide series are lanthanum and cerium, the oxides of which are used in the mole ratio of 1:1. The Group II A, III A and IV A elements are

calcium, aluminium and silicon respectively. The composite support material contains oxides of the said elements having mole ratio of calcium oxide to alumina to silica of 2 to 4:1:2 to 5.
The precipitation is carried out by adding metal nitrate solution to the solution of an alkali metal carbonate in the pH range of about 7 to 10 or by adding the solution of the alkali metal carbonate to metal nitrate solution in the pH range of about 2 to 7.
In the practice of this invention, sodium carbonate is used as the preferred alkali metal carbonate. The addition of copper nitrate solution to the alkali metal carbonate or vice versa at a controlled slow rate with vigorous agitation is carried out to ensure that the precipitate is not getting agglomerated.
Copper nitrate solution is prepared by dissolving the said nitrate in deionised water. Copper solution which is taken for precipitation contains between 30 and 100 grams of copper per litre, preferably between 70 and 90 grams per litre. Sodium carbonate solution is prepared by dissolving the said salt in deionised water. Sodium carbonate solution used for precipitation contains about 50-250 grams per litre, preferably 100-200 grams per litre of the said carbonate.
According to this invention, a mixture of copper nitrate solution and the said promoters, is added to a well-agitated solution of the alkali metal containing the said support material. Alternatively, the alkali metal solution and the mixture of copper nitrate solution, the said promoters and support material, are simultaneously added to boiling water. The pH of the mixture during precipitation is maintained at about 6 to 8. The temperature is maintained in the range of about 50° to 100°C, preferably at 60° - 80°C.
The catalyst can also be prepared by decomposing copper ammine carbonate in presence of the said promoters and support material. A solution of the said ammine carbonate is agitated with the said promoters and support material. The mixture is added dropwise to boiling water to decompose the said ammine carbonate to give copper hydroxycarbonate on the said support incorporating the promoter oxides uniformly in the system. There are several advantages for the preparation of catalyst from metal ammine carbonate solution. Since alkali

metal carbonate is not involved in the preparation of catalyst, the extent of washing of the precipitate can be minimized. Impact of using metal nitrate solution on environment can also be prevented. Further processing of the precursor obtained by this method is carried out in a similar manner as described herein for the preparation of catalyst from metal nitrate solution.
The precipitation is carried out over a period of 2 to 5 hours. The precipitated material is aged for a period of about 1-3 hours to improve crystallinity. The aging is carried out in the temperature range of about 60° to 80°C. The slurry is then cooled to about 30°-35°C. Since the precipitation is carried out with excess of alkali metal carbonate than the stoichiometric requirement, the precipitate is to be thoroughly washed with deionised water to remove the alkali metal ions. Even the trace amount of alkali metal present in the catalyst is likely to reduce the dispersion of active phase, which reduces the performance of the catalyst remarkably. Therefore, the aged precipitate is washed with dionised water for about 3 to 10 times by filtration and resulurrying of the precipitated mass to remove the alkali metal ions. The washed precipitate, which contains metal hydroxy carbonate and promoters on the composite support material, is decomposed to give metal oxide on the support containing promoters. Drying and calcination of the washed precipitate are carried out in a precisely controlled slow heating rate to achieve maximum dispersion of active phase on the support. Controlled drying and calcination can also lead to a product with high surface area.
The washed precipitate is dried at about 120°-250°C for about 3 to 12 hours and calcined at a temperature of about 300°C to 600°C, preferably at 400°-500°C for about 2 to 6 hours. The programmed heating is carried out at a controlled rate of about 30° to 100°C per hour, preferably 40° to 60°C per hour.
The aluminate of an alkaline earth metal is used as a binder and graphite is used as the lubricant. In the practice of this invention, the preferred alkaline earth metal used is calcium. The calcined mass is mixed with the said binder and the lubricant, and is ball-milled. Then the sample is granulated to 12 -100 mesh size. Finally, the granulated sample is tabletted to form the cylindrical particles. The tabletted material is calcined at a temperature of about 400°-700°C, preferably at 450°C-550°C for about 2 to 6 hours.

The catalyst according to the present invention, is characterized by the copper oxide content of about 40 to 65% by weight and copper dispersion of about 20 to 30%. The atomic ratio of copper to lanthanum to cerium is from about 45:2:1 to about 145:2:1. Surface area of the catalyst prepared by the method of the present invention is about 50 to 80 m2/g with a total pore volume of about 0.15 to 0.35 ml/g. The side crushing strength of the catalyst particle is about 15 to 30 kg.
The catalyst is evaluated in the fixed bed in a mild steel/stainless steel single tube reactor, which is heated electrically by using a vertical tube furnace in which the reactor is fixed co-axially. The temperature of the tube furnace is controlled properly by using an automatic temperature controller. Alternatively, the catalyst is evaluated in the fixed bed in mild steel/stainless steel multitubular reactor which consists of about 2000 to 3000 tubes, is heated by circulating hot oil through a vertical jacket in which the said reactor is fixed co-axially. The volume of the catalyst used for evaluation in the said reactor is about 30 to 1290 ml. A desired volume of the catalyst is charged in the said reactor and is reduced by passing a mixture of nitrogen and hydrogen (with varying amounts of the latter from about 0.01 to 20% by volume) through the catalyst bed at a temperature of about 180°-220°C and a space velocity of about 1000 to 2200 hr" for about 8 to 168 hours. The catalyst is then evaluated in-situ by passing a mixture of nitrobenzene vapour and hydrogen through the catalyst bed at a temperature of about 150° to 230°C, preferably at 160° to 220°C and at a mole ratio
(nitrobenzene: hydrogen) of 1:30 to 1:15, and a space velocity of about 1000-2000 hr .
Nitrobenzene containing about 500-800 ppm of m-dinitrobenzene, produced by M/s. Hindustan Organic Chemicals Limited, Rasayani has been used as feed stock for evaluation of the catalyst.
Under the experimental condition employed, the catalyst of the present invention exhibits almost complete conversion of nitrobenzene which is indicated by the negligibly small amount of unreacted nitrobenzene (about 0.2-200 ppm) in the hydrogenated mass. The catalyst gives about 98.0-99.9% aniline and 0.10-2.0 % N- phyenylcyclohexylamine (PCHA). The properties of the catalyst viz., chemical composition, surface area, pore volume and mechanical strength (side crushing strength) are determined by known methods.

Examples I to IV are given for the preparation of catalyst and Examples V to VIII are given for the evaluation of the catalyst for the conversion of nitrobenzene to aniline in the vapour phase.
The invention is described further with reference to the following examples. The examples are given only for illustration which do not limit the scope of this invention.
EXAMPLE-I
A mixture of copper nitrate solution (35 litres, 7.2% Cu) and oxides of lanthanide elements (0.42 kg which contains La2O3 and Ce02 in the mole ratio of 1:1) is added dropwise to a solution of sodium carbonate (29 litres, 15%) containing the support material (1.1 kg material which contains CaO, alumina and silica in the mole ratio of 2:1:2) with vigorous agitation. The temperature is maintained at 60°-80°C. The pH of the slurry is 7.0. The precipitation is carried out over a period of 3 hours. The precipitate is aged at 60°-80°C for 1 hour and is cooled and washed five times by filtration and reslurrying the precipitate. The washed precipitate is dried at 120°C for 12 hours and is heated at a programmed slow heating rate of 40°C per hour upto 450°C and is kept at 450°C for 6 hour to complete the calcination. The powder catalyst sample thus obtained has got a bulk density of 1.1 kg/litre and loss on ignition at 540°C is 5% by weight. The said powder is ball-milled for 1 hour after mixing with the said binder (0.350 kg) and the said lubricant (0.050 kg). Then mix mulling of the above material is done with deionised water for 30 minutes and is dried at 150°C for 4 hours. The dried sample is granulated to 12-100 mesh size and finally tabletted to cylindrical shape of 4.7 mm x 4.7 mm size, and calcined at 450°C for 4 hours.
The finished product exhibits a surface area of 65.0 m2/g with a pore volume of 0.15 ml/g. The catalyst contains 47.93% copper having atomic ratio of copper to lanthanum to cerium of 47:2:1. The side crushing strength of the catalyst pellets is 26.0 kg and it has a bulk density of 1.5 kg/1.

EXAMPLE-II
Copper ammine carbonate solution (26 litres, Cu, 9.8%) is agitated well with 1.2 kg of the support material (containing CaO, alumina and silica in the mole ratio of 4:1:3) and 0.25 kg of rare earth oxides (La2O3 and CeO2) in the mole ratio of 1:1). The mixture is added dropwise to boiling water to decompose the said ammine carbonate. The temperature during decomposition is maintained at 80°-100°C. The decomposition is carried out over a period of three hours. The mixture is cooled to 30°-35°C. The precipitated material is washed twice by filtration and reslurrying, and is dried at 120°C for 8 hours. It is calcined in a similar manner as described in Example -1. The powder catalyst sample has got a bulk density of 0.9kg/litre and loss on ignition at 540°C is 4.5% by weight. The above sample is mixed with 0.38 kg of the said binder and 0.050 kg of the said lubricant, and is processed further to the finished product as described in Example-I. The finished product exhibits a surface area of 63 m /g with a pore volume of 0.17 ml/g. The catalyst contains 47.37% copper having a mole ratio of copper to lanthanum to cerium of 75:2:1. The bulk density of the catalyst is 1.4 kg/litre. It exhibits a side crushing strength of 28.0 kg.
EXAMPLE-III
Copper nitrate solution (35 litres, 7.2% Cu), rare earth oxides (0.25kg which contains lanthana and ceria in the mole ratio of 1:1) and the support material (1.6 kg containing CaO, AI2O3 and SiO2 in the mole ratio of 2:1:2) are mixed and agitated well. Sodium carbonate solution (29 litres, 15%) and the above mixture are added simultaneously to boiling water under agitation maintaining the pH in the range of 6-8. The temperature is maintained at 60°-80°C. The precipitate is aged for 2 hours and is cooled and filtered. It is washed five times by filtration and reslurrying, and is dried at 250°C for 3 hours. The dry powder is calcined at 450°C for 3 hours. The dry powder which has got a bulk density of 0.98 kg/litre, exhibits 13.0% loss on ignition at 540°C. The above powder is mixed with 0.30 kg of the said binder and 0.050 kg of the said lubricant, and is processed further to finished product as described in

Example-I. The finished product exhibits a surface area of 58 m2/g and a pore volume of 0.21 ml/g. The copper content in the catalyst is 48.73%. The atomic ratio of copper to lanthanum to cerium is 77:2:1. The catalyst which exhibits a side crushing strength of 18 kg, has a bulk density of 1.4 kg/litre.
EXAMPLE-IV
In this example, the catalyst is prepared by a similar method as described in Example-III except the volumes/quantities of raw materials used in the experiment. The volumes of copper nitrate and sodium carbonate solutions are 3500 litres and 2900 litres respectively. The quantity of rare earth oxides (La2O3 and CeO2 in the mole ratio of 1:1) is 25 kg. The quantities of the support material, the binder and the lubricant are 160 kg, 30 kg and 5 kg respectively.
The catalyst exhibits a surface area of 55 m2/g and a pore volume of 0.20 ml/g. The copper content in the catalyst is 49.37%. The atomic ratio of copper to lanthanum to cerium is 97:2:1. The bulk density of the catalyst is 1.3 kg/1. The side crushing strength of the catalyst pellet is 14.7 kg.
EXAMPLE-V
The catalyst of Example-I (30ml) charged in a stainless steel single tube reactor was reduced at 200°-215°C by passing a mixture of nitrogen and hydrogen with varying amounts of the latter from 1 to 10% by volume at a space velocity of 1090-1110 hr" for 10 hours. The hydrogenation of nitrobenzene to aniline was carried out in-situ by passing a mixture of nitrobenzene vapour and hydrogen at a temperature of 160°-l65°C, a space velocity of 1146 hr" and a mole ratio (nitrobenzene : hydrogen) of 1:20. The mixture of nitrobenzene vapour and hydrogen was passed through the catalyst bed for 20 hours under the reaction conditions as hereinbefore described.

A sample of the hydrogenated mass, collected after 20 hours, was analyzed. The results of analysis are as follows :
Aniline : 98.6 %
PCHA : 1.2 %
Unreacted
nitrobenzene : 200 ppm
EXAMPLE-VI
This experiment was carried out using the catalyst of Example - II in a similar manner under similar experimental conditions except the duration of passing the mixture of nitrobenzene vapour and hydrogen through the catalyst bed. In this experiment, the said mixture was passed through the catalyst bed for 16 hours. A sample of the hydrogenated mass collected after 16 hours, was analyzed. The results of analysis are as follows:
Aniline : 98.04 %
PCHA : 1.89 %
Unreacted
nitrobenzene : 10 ppm
EXAMPLE -VII
This experiment was carried out using the catalyst of Example - III in a similar manner under similar experimental conditions as described in Example - V. The results of analysis of the hydrogenated mass are as follows:
Aniline : 99.35 %
PCHA : 0.24 %
Unreacted
nitrobenzene : 1.85 ppm

EXAMPLE - Vffl
The experiment was carried out in a mild steel multitubular reactor using the catalyst of Example-IV. The volume of the catalyst charged in a tube of the said reactor is 1270 ml. The catalyst is reduced at 191°-219°C by passing a mixture of nitrogen and hydrogen (with varying amounts of the latter from 0.01 to 5.30% by volume) through the catalyst bed at a space velocity of 2080-2140 hr"1 for 120 hours. The catalyst was then evaluated in-situ by passing a mixture of nitrobenzene vapour and hydrogen through the catalyst bed at a temperature of 155°-159°C, a space velocity of 1890-1945 hr" and a mole ratio (nitrobenzene : hydrogen) of 1:28.46 to 29.34. A sample of the hydrogenated mass collected after 157 hours (from start-up of the reactor) was analyzed. The results of analysis are given below:
Aniline : 99.6 %
PCHA : 0.4 %
Unreacted
nitrobenzene : 0.41 ppm

We claim
A process for the preparation of a transition metal catalyst for the conversion of nitrobenzene to aniline in the vapour phase which catalyst contains oxide of the said metal which is promoted with the oxide or oxides of one or two elements), preferably oxides of two elements of the lanthanide series and is supported on a composite support material comprising oxides of the Group II A, in A and IV A elements, which is prepared by the process comprising the steps of :
(i) precipitating the said metal from its salt solution as metal hydroxycarbonate on the said support containing oxide(s) of the lanthanide elements) at 50°-100°C and aging the precipitated material at 60°-80°C;
(ii) cooling the precipitated material and washing the same with deionised water;
(iii) drying the washed material at 120°-250°C;
(iv) calcining the dried material at 300°-600°C, preferably at 400°-500°C;
(v) mixing the calcined material with a suitable binder and a lubricant;
(vi) granulating the resulting material to 12-100 mesh size;
(vii) tabletting the granulated material to catalyst particles of desired shape and size;
(viii) finally calcining the tabletted material at 400°-700°C, preferably at 450°C-550°C to produce the finished product of desired higher mechanical strength.
2. A process as claimed in claim 1, wherein the transition metal is copper.
3. A process as claimed in claim 1, wherein the lanthanide elements are lanthanum and cerium.
4. A process as claimed in claim 1, wherein the Group II A, HI A and IV A elements are calcium, aluminium and silicon respectively.
5. A process as claimed in claim 1, wherein the metal salt used in step (i) is copper nitrate or copper arnmine carbonate.

6. A process as claimed in claim 1, wherein in step (i), the precipitation is carried out over a period of 2 to 5 hours.
7. A process as claimed in claim 1, wherein in step (i), the precipitated material is aged for a period of 1 to 3 hour(s).
8. A process as claimed in claim 1, wherein in step (ii), the precipitated material is cooled to 30° to 35°C.
9. A process as claimed in claim 1, wherein in step (ii), the washing is carried out with deionised water for 3 to 10 times by filtration and reslurrying of the precipitated mass.
10. A process as claimed in claim 1, wherein in step (iii), the drying is carried out for 3 to 12 hours.
11. A process as claimed in claim 1, wherein in step (iv), the calcination is carried out for 2 to 6 hours.
12. A process as claimed in claim 1, wherein in step (v), the binder and the lubricant used are calcium aluminate and graphite respectively.
13. A process as claimed in claim 1, wherein in step (vii), the desired length of the said tablet is about 3 to 6 mm, preferably 4.7 to 5.2 mm and the desired diameter is about 3 to 6 mm, preferably 4.7 to 5.2 mm,
14. A process as claimed in claim 1, wherein in step (viii), the calcination of the tabletted material is carried out for 2 to 6 hours.
15. A process as claimed in claims 1 to 14, wherein the side crushing strength of the catalyst particles is 15 to 30 kg.
16. A process as claimed in claims 1 to 15, wherein the surface area and the pore volume of the finished product are 50-80 m2/g and 0.15-0.35 ml/g respectively.
17. A process as claimed in claims 1 to 16, wherein the atomic ratio of copper to lanthanum to cerium is from 45 : 2 :1 to 145 : 2 : 1.

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Patent Number

197777

Indian Patent Application Number

528/MUM/2003

PG Journal Number

42/2008

Publication Date

17-Oct-2008

Grant Date

26-Dec-2005

Date of Filing

26-May-2003

Name of Patentee

M/S. HINDUSTAN ORGANIC CHEMICALS LIMITED

Applicant Address

RASAYANI, DIST-RAIGAD, PIN-410 207, MAHARASHTRA, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. DAS JAGAT KUMAR	HINDUSTAN ORGANIC CHEMICALS LIMITED, P.O. RASAYANI, DIST-RAIGAD, PIN-410 207, MAHARASHTRA, INDIA.
2	MR. JOSHI DHANANJAY VINAYAK	HINDUSTAN ORGANIC CHEMICALS LIMITED, P.O. RASAYANI, DIST-RAIGAD, PIN-410 207, MAHARASHTRA, INDIA.
3	MR. RAMKRISHNA MUDDARANGAIAH	HINDUSTAN ORGANIC CHEMICALS LIMITED, P.O. RASAYANI, DIST-RAIGAD, PIN-410 207, MAHARASHTRA, INDIA.
4	DR. NITTALA VENKATA RAMA RAO	HINDUSTAN ORGANIC CHEMICALS LIMITED, P.O. RASAYANI, DIST-RAIGAD, PIN-410 207, MAHARASHTRA, INDIA.
5	MRS. LALLJEE ARSHIA ALTAF	M/S. SUD-CHEMIE INDIA PVT. LIMITED, P.O. BINANIPURAM, PIN-683502, KERALA, INDIA.
6	MRS. DHADALLA ABDULRAUF PEERMOHAMED	M/S. SUD-CHEMIE INDIA PVT. LIMITED, P.O. BINANIPURAM, PIN-683502, KERALA, INDIA.
7	DR. KARUKAPADATH KUNJIMOIDEEN ABDUL RASHID	M/S. SUD-CHEMIE INDIA PVT. LIMITED, P.O. BINANIPURAM, PIN-683502, KERALA, INDIA.
8	DR. RUGMINI SREEKALA	M/S. SUD-CHEMIE INDIA PVT. LIMITED, P.O. BINANIPURAM, PIN-683502, KERALA, INDIA.
9	MR. PHILIP PRAVEEN	M/S. SUD-CHEMIE INDIA PVT. LIMITED, P.O. BINANIPURAM, PIN-683502, KERALA, INDIA.

PCT International Classification Number

N/A

PCT International Application Number

N/A

PCT International Filing date

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