GB834776A - A method of preparing a liquid hydrocarbon fuel having a high heat of combustion perunit volume - Google Patents

Abstract

A liquid hydrocarbon fuel, e.g. for jet aircraft, is obtained from an aromatic petroleum gas oil by distilling to obtain a fraction having a boiling range in the range 175-375 DEG C., subjecting this to desulphurizing hydrogenation, further hydrogenating at a lower temperature to reduce the aromatic content to below 10% by weight and recovering a product fraction having a boiling range between 165 DEG and 345 DEG C. The preferred starting material is one obtained as a residue from a thermal or catalytic cracking operation. The aromatic concentrate is preferably obtained by solvent extraction with phenol, furfural, nitrobenzene, sulphur dioxide, aniline, mixtures of sulphur dioxide and benzene or mixtures of cresol and water. The concentrate is contacted with a sulphur resistant catalyst such as the oxides or sulphides of Group VI metals which may be mixed with oxides or sulphides of Group II and/or VIII metals, or sulphides of Group VIII metals. Preferred are (1) mixtures of the oxides of molybdenum, zinc and magnesium, (2) molybdenum sulphide, (3) tungsten sulphides supported on activated clay, (4) iron sulphides supported on activated bentonitic clay, (5) tungsten-nickel-molybdenum-alumina. Suitable conditions are 315-485 DEG C., 35-285 kg./cm.2, LHSV of 0.5-4 and a hydrogen feed rate of 280-5600 standard cubic metres per cubic metre of feed. The second hydrogenation is preferably effected with a sulphur sensitive catalyst although the same type of catalyst as in the first stage can be used. Preferred are metallic nickel, platinium, palladium, cobalt or iron supported on aluminium silicate, silica, or bentonitic or montmorillonitic clay. Conditions may be 145-375 DEG C., 17.352 kg./cm.2, LHSV of 0.5-10 and a hydrogen feed rate of 280-2800 standard cubic metres per cubic metre of feed. The product will generally have a freezing point between -30 DEG and -57 DEG C. and a heat of combustion of 8450-9165 kcal/litre or 9730-10565 kcal/kg.ALSO:A liquid hydrocarbon fuel, e.g. for jet aircraft, is obtained from an aromatic petroleum gas oil by distilling to obtain a fraction having a boiling range in the range 175-375 DEG C., subjecting this to desulphurizing hydrogenation, further hydrogenating at a lower temperature to reduce the aromatic content to below 10% by weight and recovering a product fraction having a boiling range between 165 DEG and 345 DEG C. The preferred starting material is one obtained as a residue from a thermal or catalytic cracking operation. The aromatic concentrate is preferably obtained by solvent extraction with phenol, furfural, nitrobenzene, sulphur dioxide, aniline, mixtures of sulphur dioxide and benzene or mixtures of cresol and water. The concentrate is contacted with a sulphur resistant catalyst such as the oxides or sulphides of Group VI metals which may be mixed with oxides or sulphides of Group II and/or VIII metals, or sulphides of Group VIII metals. Preferred are (1) mixtures of the oxides of molybdenum, zinc and magnesium (2) molybdenum sulphide, (3) tungsten sulphides supported on activated clay, (4) iron sulphides supported on activated bentonitic clay, (5) tungsten-nickel-molybdenum-alumina. Suitable conditions are 315-485 DEG C., 35-285 kg./cm.2, LHSV of 0.5-4 and a hydrogen feed rate of 280-560 standard cubic metres per cubic metre of feed. The second hydrogenation is preferably effected with a sulphur sensitive catalyst although the same type of catalyst as in the first stage can be used. Preferred are metallic nickel, platinium, palladium, cobalt or iron supported on aluminium silicate, silica, or bentonitic or montmorillonitic clay. Conditions may be 145-375 DEG C., 17-352 kg./cm.2, LHSV of 0.5-10 and a hydrogen feed rate of 280-2800 standard cubic metres per cubic metre of feed. The product will generally have a freezing point between -30 and -57 DEG C. and a heat of combustion of 8450-9165 kcal/litre or 9730-10565 kcal/kg.