Title of Invention

PROCESS FOR PRODUCTION OF AVIATION TURBINE FUEL(ATF)/PREMIUM GRADE KEROSENE THROUGH LOW PRESSURE HYDROTREATING

Abstract

ABSTRACT The present invention relates to the process for production of Aviation Turbine Fuel (ATF) or premium grade kerosene of boiling range between 125 and 325°C, but commonly between 140-280°C, with very low sulfur (particularly mercaptans) from high sulfur feed through hydrotreating at pressure ranging between 1 bar and 15 bar, but preferably between 4 bar and 7 bar. The reaction temperature can be between 150°C and 350°C, but preferably between 200 to 300°C. The process has advantage of flexibility of operating range leading to different product properties, all essentially having very low sulfur particularly mercaptans. The process is particularly suitable for production of commercial ATF / premium grade kerosene (SKO) and can be extended to other petroleum fractions, specially naphtha and diesel, but not limited to these alone.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See section 10;Rule 13) PROCESS FOR PRODUCTION OF AVIATION TURBINE FUEL (ATF) / PREMIUM GRADE KEROSENE THROUGH LOW PRESSURE HYDROTREATING" INDIAN OIL CORPORATION LIMITED, a Public Limited Company, having its Head Office at G-9, All Yavar Jung Marg, Bandra (East), Mumbai 400 051, India. The following specification (particularly) describes the nature of the invention and the manner in which it is to be performed. ORIGINAL GRANTED 10-8-2004 FIELD OF THE INVENTION The present invention relates to a process for preparing premium grade Aviation Turbine Fuel (ATF) and / or premium grade kerosene having negligible mercaptans, good color, low sulfur and low acidity from petroleum feed of same boiling range having undesirable properties such as high mercaptans content, high sulfur content and high acidity. The process uses a route where hydrogen is one of the reactants and the operating pressure is very low. More particularly, the present invention relates to a hydro-treatment process for preparing ATF and / or premium grade kerosene having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from commercial ATF/kerosene feed mercaptans and sulfur contents in excess of 60 ppm and 2400 ppm respectively, said process comprising the step of reacting the commercial ATF/kerosene feed with a source of hydrogen in the presence of a Ni-Mo based catalyst at pressure in the range of 1-15 bar, temperature in the range of 150°C - 350°C and space velocity in the range of 4-6h~' in a reactor wherein the source of hydrogen to oil ratio is in the range of 125-250 Nm3/m3. BACKGROUND OF THE INVENTION Aviation Turbine Fuel (ATF) demand is expected to increase rapidly in the wake of major developments in aviation industry and the refineries need to respond promptly to the challenge of producing premium grade ATF. Air travel is projected to grow in popularity in the years to come and the refinery that produces jet fuel at the lowest cost will be in the best position to compete in this market. The refinery that produces high quality jet fuels can find attractive markets for ATF product throughout the world. There is also huge demand for premium grade kerosene. ATF and / or premium grade kerosene can be produced through distillation of crude followed by some post-treatment or by hydroprocessing route. For the former case, mercaptan content is generally higher than specifications and is crude specific. In conventional hydroprocessing process, high pressure (of the order of at least 40 bars in hydrotreating and at least 160 bars in hydrocracking) is applied leading to very high equipment and operating costs. Mercaptan is the generic name for a family of organic compounds where sulfur and a hydrogen atom (SH) are bonded to one of the carbon atoms in the molecule. The hydrogen atom in the SH radical can ionize and produce a mildly acidic environment, which may lead to corrosion. The most noticeable characteristic of mercaptans is their strong, unpleasant odor even when their concentration is only a few parts per million. Many hydrocarbons contain sulfur in the form of mercaptans (thiols). Mercaptans are almost invariably present in LPG, cracked gasolene, straight run gasolines, natural gasolines, and in heavier hydrocarbon distillates including for example kerosene and fuel oil. Mercaptans need to be removed from ATF due to corrosion and odour problems. Other specifications of ATF include acidity, aromatics, olefins, smoke point, sulfur, mercaptans, freeze point, color, and water separation index, etc. The refinery production of jet fuel normally involves withdrawing a side stream product from the crude oil fractionator that requires caustic treatment followed by water washing, salt drying, and clay filtration. Certain polar compounds can be removed from jet fuel by clay treating. In this relatively simple process, the fuel is allowed to pass through a bed of clay. Certain classes of polar compounds, especially those that act as surfactants, adsorb onto the surface of the clay and thus are removed from the fuel. Removal of surfactants from hydrocarbon distillate using post treatment methods employing clay is well known in the art. Finally, the product may be subjected to other conventional treating methods so that the product can meet all jet fuel specifications. The conventional routes for removing mercaptans from ATF are extraction, adsorption, oxidation, extraction-oxidation technology, etc. which face severe problems like caustic handling, environmental fouling, inflexibility to different feedstocks, etc. There is also very little flexibility available to control product mercaptans level at varying feed mixes. There have been many attempts to provide processes, which would remove or convert mercaptans. Some of the earliest processes included treatment of the hydrocarbon fraction with caustic, clays, etc. A significant improvement in the treating of hydrocarbon fractions was made when the Merox Process was developed in 1950s. The art relating to the treatment of mercaptan containing sour hydrocarbon distillate and the regeneration of spent caustic solution is well developed and the processes and the apparatus therefore are subject of many patents the latest of which are discussed in this section. US Patent has been granted to Putman (6,231,752 Bl) for removal of mercaptans and diolefins from naphtha range feed using reactor system in hydrogen atmosphere but the process lacks capability for dealing with higher boiling feed (kerosene / diesel) and no claim for color or acidity improvement has been cited. US Patent No. 4,498^978 granted to Frame deals with a process for sweetening a sour hydrocarbon fraction (gasoline or kerosene) containing mercaptan with an oxidizing agent by passing the fraction and the oxidizing agent into contact with a heterogeneous admixture of a metal chelate mercaptan oxidation catalyst and a solid desiccant at about 70 bar pressure. A variation of the process has been reported in US Patent NQ. 4,498,977 where a solid carrier material having an average particle size of less than about 110 mesh has been applied. A process (US Patent No. 4,121,998) comprises contacting the sour distillate with a catalytic composite in the presence of an alkaline reagent at oxidation conditions. The catalytic composite comprises a solid adsorptive support impregnated with a polynuclear aromatic sulfonic acid and a metal phthalocyanine. US Patent Nos. 4,490,246 & 4,199,440 have been granted to Verachtert for development of a process for catalyzed oxidation of mercaptans to disulfides (Merox). In another invention, the conversion is effected during passage of the hydrocarbon and an aqueous stream downward through a cylindrical mass of liquid-liquid contact material (US Patent No. 4,481,106). Urban has disclosed a process for oxidation of difficultly oxidisable mercaptans contained in petroleum fraction (US Patent No. 4,481,107). Another type of oxidation process has been invented by Carlson et al where the distillate is treated in contact with a solid composite prepared by impregnating high density activated charcoal particles with a metal phthalocyanine catalyst from an aqueous solution. The process, its variations (oxidation route) along with supported metal preparation, etc. have been granted US Patent Nos. 4,248,694; 4,141,819; 4,121,999; 4,113,604; 4,098,681; 4,087,378; 4,070,271; 4,033,860; 4,018,705 & 4,003,827. In another method, the sour distillate is treated in contact with an oxidizing agent and a catalytic composite comprising a metal chelate mercaptan oxidation catalyst impregnated on a basic anion exchange resin (US Patent No. 4,206,043). A catalyst and method for converting mercaptans and mercaptide compounds in aqueous alkaline solution to disulfides where the catalytic agent is a metal complex synthesized from 3,3',4,4'-benzophenonetetracarboxylic dianhydride has been awarded U.S. Patent (No. 4,090,954). US patents have been granted for various methodologies for preparation of catalysts (composite) particularly useful for the oxidation of mercaptans and / or removal of gums contained in a sour petroleum distillate (Nos. 4,364,843; 4,298,502; 4,124,531; 4,107,078; 3,972,829; 3,931,054). Mercaptan extraction process with recycled alkaline solution has been patented. In US Patent No. 4,362,614, granted to Asdigian, involves water removal from an alkaline solution which is used to extract mercaptans from a hydrocarbon stream by contacting the alkaline solution with a warm hydrocarbon vapor stream. US Patent Nos. 4,104,155 & 4,040,947 have been granted to Christman for invention of a variation of mercaptan extraction process using stripped alkaline solution. US Patent No. 4,081,354 has been granted for liquid-liquid extraction process using caustic for removal of mercaptans from hydrocarbon streams.lt is claimed that high efficiency is obtained over a wide range of flow rates through a single extraction column by the provision of an intermediate product drawoff means located between a downstream section of extraction trays having greatest efficiency at low throughputs and an upstream section of trays having peak efficiency at high throughputs. US Patent Nos. 2,853,432; 2,921,021; 2,937,986 are also granted for this type of mercaptan extraction. A Japanese Patent (JP3292396) has been granted to Fuchigami Jun et al. on hydrotreatment route for production of good quality kerosene / gas oil of boiling range 340°C to 390°C using high hydrogen pressure of 20 - 70 bar. In order to meet the growing demand of high quality ATF & premium grade kerosene (SKO), the current invention uses a novel low pressure hydroprocessing technology for production of premium grade ATF / SKO. The process has the capability of removing mercaptan / sulfur from ATF/kerosene at low pressure, moderate temperature, low hydrogen to oil ratio and high space velocity. It has been found that the process can reduce mercaptans to less than 10 ppm from commercial ATF/kerosene feed having more than 60 ppm mercaptan level. Acidity, colour and all other critical properties of the product are improved during the process of the present invention. The process of the present invention may also be used for removal of mercaptans and / or sulfur from other hydrocarbon stream having same boiling range. OBJECTS OF THE INVENTION The main object of the present invention is to provide a process for preparing premium grade Aviation Turbine Fuel (ATF) and / or premium grade kerosene having negligible mercaptans, good color, low sulfur and low acidity from petroleum feed of same boiling range having undesirable properties such as high mercaptans content, high sulfur content and high acidity at pressures as low as 1 to 15 Bars. Another object of the present invention is to provide an improved process for preparing ATF having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from commercial grade ATF feed having mercaptans and sulfur contents in excess of 60 ppm and 2300 ppm respectively. Yet another object of the present invention is to provide an improved process for preparing premium grade kerosene having sulfur content less than 300 ppm from commercial grade kerosene having sulfur content in excess of 2350 ppm. STATEMENT OF THE INVENTION Accordingly, the present invention provides a hydro-treatment process for preparing Aviation Turbine Fuel (ATF) and / or premium grade kerosene such as herein described having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from petroleum feed of same boiling range having mercaptans and sulfur contents in excess of 60 ppm and 2400 ppm respectively, said process comprising the step of reacting the petroleum feed with a source of hydrogen such as herein described in the presence of a Ni-Mo based catalyst at pressure in the range of 1-15 bar, temperature in the range of 150°C - 350°C and space velocity in the range of 4-6h_1 in a reactor wherein the source of hydrogen to oil ratio is in the range of 125 - 250 NmV. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a hydro-treatment process for preparing ATF and / or premium grade kerosene having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from petroleum feed of same boiling range having mercaptans and sulfur contents in excess of 60 ppm and 2400 ppm respectively, said process comprising the step of reacting the petroleum feed with a source of hydrogen in the presence of a Ni-Mo based catalyst at pressure in the range of 1-15 bar, temperature in the range of 150°C - 350°C and space velocity in the range of 4-6h~1 in a reactor wherein the source of hydrogen to oil ratio is in the range of 125 - 250 Nm3/m3. More particularly, the present invention provides an improved process for preparing ATF and / or premium grade kerosene having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from commercial grade ATF/petroleum feed having mercaptans and sulfur contents in excess of 60 ppm and 2400 ppm respectively, said process comprising the step of reacting the commercial grade ATF/petroleum feed with a source of hydrogen in the presence of a Ni-Mo based catalyst at pressure in the range of 1-15 bar, temperature in the range of 150°C -350°C and space velocity in the range of 4-6h"' in a reactor wherein the source of hydrogen to oil ratio is in the range of 125 - 250 Nm3/m3. In an embodiment of the present invention, the commercial ATF/kerosene feed has mercaptan content more than 60 ppm. In another embodiment of the present invention, the commercial ATF/kerosene feed has sulfur level higher than 2400 ppm. In yet another embodiment of the present invention, the commercial ATF/kerosene feed has boiling point in the range of 125° to 325° C and preferably in the range of 140-280° C. In still another embodiment of the present invention, the commercial ATF/kerosene feed gives a positive result to Doctor's test. In a further embodiment of the present invention, the commercial ATF/kerosene feed has a saybolt color rating of+21. In one more embodiment of the present invention, the commercial ATF/kerosene feed has acidity in the range of 0.035 to 0.050 mg KOH/g. In one another embodiment of the present invention, the catalyst is Nickel-Molybdenum supported on alumina. In an embodiment of the present invention, the metal dispersion of Nickel on alumina is in the range of 0.1 to 0.4 and that of Molybdenum is in the range of 0.6 to 0.9. In another embodiment of the present invention, the physical surface area of the support material (alumina) is in the range of l20 to 200 m2/g. In still another embodiment of the present invention, the pore volume of the catalyst is between 0.2 to 0.6 cc/gm. In yet another embodiment of the present invention, the average pore diameter of the catalyst is in the range of 70 to 130 A. In a further embodiment of the present invention, the pressure is preferably in the range of 4 to 15 bars. In one more embodiment of the present invention, the pressure is most preferably in the range of 4 to 7 bars. In one another embodiment of the present invention, the temperature is preferably in the range of 200 to 300° C. In an embodiment of the present invention, the source of hydrogen is mixed with the commercial ATF/kerosene feed at pressure in the range of 4 to 7 bar and allowed to pass through the reactor filled with the catalyst and maintained at 200 to 300° C. In another embodiment of the present invention, the source of hydrogen may be pure hydrogen or reformer off gas. In still another embodiment of the present invention, the source of hydrogen is preferably reformer off gas comprising 90.0 to 94.9% hydrogen, 1.2 to 2.4% methane, 1.3 to 2.9% ethane, 1.4 to 2.8% propane, 0.5 to 1.0% n-butane and 0.1 to 0.2% n-pentane. In yet another embodiment of the present invention, the reformer off gas comprises of 92.4% hydrogen, 2.4% methane, 2.3% ethane, 1.8% propane, 0.95% n-butane and 0.15% n-heptane. In a further embodiment of the present invention, the reactor is selected from a three phase reactor, a tubular fixed bed reactor or a down flow trickle bed reactor and preferably a down flow trickle bed reactor. In one more embodiment of the present invention, the commercial ATF/kerosene feed is mixed with little excess than stoichoimetric amount of source of hydrogen. In one another embodiment of the present invention, the premium grade Aviation Turbine Fuel (ATF) or kerosene obtained from the reactor is optionally passed through a separator to separate unreacted hydrogen (if any) from the premium grade ATF or kerosene. In an embodiment of the present invention, the premium grade ATF / kerosene thus obtained has mercaptan content less than 10 ppm, more preferably less than 5 ppm and most preferably less than 2 ppm. In another embodiment of the present invention, the premium grade ATF / kerosene thus obtained has sulfur content less than 250 ppm. In still another embodiment of the present invention, the premium grade ATF / kerosene thus obtained has acidity less than 0.024 mg KOH/gm and preferably less than 0.013 mg KOFI/gm. In yet another embodiment of the present invention, the premium grade ATF / kerosene thus obtained tests negative in Doctor's test. In a further embodiment of the present invention, the premium grade ATF / kerosene thus obtained has saybolt color rating in the rage of+21 to +24. In one more embodiment of the present invention, the premium grade ATF / kerosene thus obtained has boiling point in the range of 125° to 325° C and preferably in the range of 140° to 280° C. The present invention relates to a process for the production of ATF/ premium grade kerosene or similar hydrocarbon liquid containing very low mercaptans less than 10. The present invention also relates to a process for the production ATF/ premium grade kerosene or similar hydrocarbon liquid containing sulfur less than 250 ppm and acidity less than 0.024 mg KOH/gm Feed: The feed is of ATF/ kerosene range having boiling range of 140-280 °C having high mercaptans, high sulfur, high acidity and moderate colour. Catalyst: In this process, Nickel-Molybdenum supported on alumina is a preferred catalyst. The physical surface area of the support material is between 120-200 m2/g, the pore volume of the catalyst is between 0.2-0.6 cc/gm. The average pore diameter is between 70-130 °A. The metal dispersion of Ni on Al is between 0.1-0.4 and Mo on Al is between 0.6-0.9. Process: In this process, feed is reacted with hydrogen in presence of catalyst in a three phase reactor. More preferably the reaction is conducted in a tubular fixed bed reactor and most preferably, in a down flow trickle bed reactor. In this process, feed is heated to the reaction temperature between 150-350°C, and preferably between 200-300°C. Hydrogen is mixed with Feed at the pressure between 1 to 15 bar but more preferably between 4 to 15 bar and most ideally between 4 bar and 7 bar. Hydrogenation reaction takes place in the reactor on the active sites of catalyst under operating conditions as described above. The product coming out of the reactor is separated from unreacted Hydrogen in a separator. Very Little Hydrogen is introduced in excess to the stoichiometric amount to the reactor. As a result, there is no need to recycle less reacted hydrogen. In an embodiment of the present invention, catalytic reformer off gas can be applied instead of pure hydrogen gas providing same products properties. The process of the present invention can be extended to remove mercaptans and sulfur from other petroleum fractions, specially naphtha and diesel, but is not limited to these alone and can be used with petroleum hydrocarbon solvents having boiling point in the rage of 125° to 325° C. Product from the reactor is hydrocarbon stream of same boiling range as that of feed and substantially have very low mercaptans, low sulfur, low acidity, excellent colour and excellent product properties required for ATF/SKO. It may be noted that the reaction takes place in once-through configuration without hydrogen recycle. This leads to substantial economic benefit because the expensive hydrogen recycle compressor is not required in the system. In an embodiment of the invention, the liquid products obtained through once through operation can be recycled back and used as feed, which further decreases the undesirable components in the final products. The invention is illustrated by Example - 1. Hydrogen is required for this process, which is a costly component in the refinery. Hence, it would be economic to use reformer off gas as the source of hydrogen in the process. Example - 2 depicts an example of use of reformer off-gas for production of ATF. While the examples are provided to illustrate the present invention, these are not intended to limit it. Example -1 Commercial ATF feed having properties as indicated in table 1 was fed along with hydrogen to a tubular reactor containing a catalyst bed having properties given in Table -2. The summary of operating conditions is given in Table - 3 and the properties of the product thus obtained are tabulated in Table - 4. Table - 2: Typical Catalyst Characteristics Table - 3: Summary of Operating Conditions Table-4: Summary of Results Table -1: Typical Feed (ATF) Properties Other Typical Product Properties: Freezing Point (at 4 bar, 250° C and H2/HC ratio: 250) - -40°C Freezing Point (at 4 bar, 250° C and H2/HC ratio: 125) = -41 °C Copper Strip Corrosion Test: 1 Silver Strip Corrosion Test: 0 BOCLE Lubricity test (at 4 bar, 250° C and H2/HC ratio: 250) = 0.55 mm BOCLE Lubricity test (at 4 bar, 250° C and H2/HC ratio: 125) = 0.54 mm Example- 2 Experimentation was conducted using kerosene feed (properties in Table 5). This was allowed to react in presence of hydrogen at various operating conditions in a tubular reactor having catalyst of typical properties as given in Table 2. The salient products' properties at different operating conditions are depicted in Table 6. It may be noted that typical smoke point and flash point are of the same order as in feed. Table 6: Summary of Results (LHSV: 4.0 h'1) Table 5: Typical feed (straight run kerosene) properties Example- 3 Hydrogen, being, one of the costliest components in the refinery, it would be economic to use reformer off gas as the source of hydrogen in the process. A gas mixture having composition (by volume) as given in table 7 has been used in the process of the present invention. Table 7: Composition of the gas mixture used as reformer off gas: The feed for this example has same properties as specified in Table 1. The product formed by application of the gas mixture having this composition has been found to meet all requirements of ATF and the properties arc reported in Table - 8. Hence, typical reformer off gas can also be applied for the process. Table- 8: Summary of Results Other Typical Product Properties: Freezing Point: -40°C Copper Strip Corrosion Test: 1 Silver Strip Corrosion Test: 0 BOCLE Lubricity Test: 0.55 mm WE CLAIM: 1.A hydro-treatment process for preparing Aviation Turbine Fuel (ATF) and / or premium grade kerosene such as herein described having mercaptans and sulfur contents less than 10 ppm and 250 ppm respectively from petroleum feed of same boiling range having mercaptans and sulfur contents in excess of 60 ppm and 2400 ppm respectively, said process comprising the step of reacting the petroleum feed with a source of hydrogen such as herein described in the presence of a Ni-Mo based catalyst at pressure in the range of 1-15 bar, temperature in the range of 150°C - 350°C and space velocity in the range of 4-6h"' in a reactor wherein the source of hydrogen to oil ratio is in the range of 125 - 250 Nm3/m3. 2.A process as claimed in claim 1, wherein the petroleum feed of same boiling range is commercial grade Aviation Turbine Fuel or commercial grade kerosene feed. 3. A process as claimed in claim 1, wherein the commercial ATF/kerosene feed has mercaptan content more than 60 ppm. 4. A process as claimed in claim 1, wherein the commercial ATF/kerosene feed has sulfur level higher than 2400 ppm. 5. A process as claimed in claim 1, wherein the commercial ATF/kerosene feed has boiling point in the range of 125° to 325° C and preferably in the range of 140-280° C. 6. A process as claimed in claim 1, wherein the commercial ATF/kerosene feed has acidity in the range of 0.035 to 0.050 mg KOH/g. 7. A process as claimed in claim 1, wherein the catalyst is Nickel-Molybdenum supported on alumina. 8. A process as claimed in claim 1, wherein metal dispersion of Nickel on alumina is in the range of 0.1 to 0.4 and that of Molybdenum is in the range of 0.6 to 0.9. 9. A, process as. claimed in claim I, wherein the. pore, volume, of the. catalyst is. between. 0.2 to 0.6 cc/gm. 10. A process as claimed in claim 1, wherein the pressure is preferably in the range of 4 to 15 bars. 11. A process as claimed in claim 1, wherein the pressure is most preferably in the range of 4 to 7 bars. 12. A process as claimed in claim 1, wherein the temperature is preferably in the range of 200 to 300° C. 13. A process as claimed in claim 1, wherein the source of hydrogen is mixed with the commercial ATF/kerosene feed at pressure in the range of 4 to 7 bar and allowed to pass through the reactor filled with the catalyst and maintained at 200 to 300° C. 14. A process as claimed in claim 1, wherein the source of hydrogen may be pure hydrogen or reformer off gas. 15. A process as claimed in claim 1, wherein the source of hydrogen is preferably reformer off gas comprising 90.0 to 94.9% hydrogen, 1.2 to 2.4% methane, 1.3 to 2.9% ethane, 1.4 to 2.8% propane, 0.5 to 1.0% n-butane and 0.1 to 0.2% n-pentane. 16. A process as claimed in claim 1, wherein the reformer off gas comprises of 92.4% hydrogen, 2.4% methane, 2.3% ethane, 1.8% propane, 0.95% n-butane and 0.15% n-heptane. 17. A process as claimed in claim 1, wherein the reactor is selected from a three phase reactor, a tubular fixed bed reactor or a down flow trickle bed reactor and preferably a down flow trickle bed reactor. 18. A process as claimed in claim 1, wherein the premium grade Aviation Turbine Fuel (ATF) or kerosene obtained from the reactor is optionally passed through a separator to separate unreacted hydrogen (if any) from the premium grade ATF or kerosene. 19. A process as claimed in claim 1, wherein the premium grade ATF / kerosene thus obtained has mercaptan content less than 10 ppm, more preferably less than 5 ppm and most preferably less than 2 pprcu 20. A process as claimed in claim 1, wherein the premium grade ATF / kerosene thus obtained has sulfur content less than 250 ppm. 21. A process as claimed in claim 1, wherein the premium grade ATF / kerosene thus obtained has acidity less than 0.024 mg KOH/gm and preferably less than 0.013 mg KOH/gm. 22. A process as claimed in claim 1, wherein the premium grade ATF / kerosene thus obtained has boiling point in the range of 125° to 325° C and preferably in the range of 140° to 280° C. 23. A hydro-treatment process for preparing Aviation Turbine Fule (ATF) such as herein described with respect to the foregoing examples. Dated this 21st day of July, 2003. G. DEEPAK SRINIWAS OF K & S PARTNERS AGENT FOR THE APPLICANTS

Documents:

733-mum-2003-abstract(granted)-(10-08-2004).pdf

733-mum-2003-abstract-(10-8-2004).doc

733-mum-2003-cancelled pages(10-08-2004).pdf

733-mum-2003-claim(granted)-(10-8-2004).doc

733-mum-2003-claims(granted)-(10-08-2004).pdf

733-mum-2003-correspondence(18-04-2007).pdf

733-mum-2003-correspondence(ipo)-(20-04-2007).pdf

733-mum-2003-form 1(08-09-2003).pdf

733-mum-2003-form 1(21-07-2003).pdf

733-mum-2003-form 19(21-07-2003).pdf

733-mum-2003-form 2(granted)-(10-08-2004).pdf

733-mum-2003-form 2(granted)-(10-8-2004).doc

733-mum-2003-form 26(21-07-2003).pdf

733-mum-2003-form 3(21-07-2003).pdf

733-mum-2003-form 5(08-09-2003).pdf

733-mum-2003-form 5(21-07-2003).pdf

733-mum-2003-petition under rule 137(17-11-2004).pdf