GB794650A - Process for the catalytic reforming of hydrocarbon mixtures of the gasoline type - Google Patents

Abstract

794,650. Reforming gasolines. NAAMLOOZE VENNOOTSCHAP DE BATAAFSCHE PETROLEUM MAATSCHAPPIJ. March 19, 1956 [March 21, 1955], No. 8472/56. Class 2 (3). Hydrocarbon mixtures of the gasoline type containing less than 30 per cent by weight of naphthenes are catalytically reformed in the presence of at least an 8-fold molar proportion of hydrogen and a platinum catalyst on a carrier with acid properties at not less than 470‹ C. and not less than 10 atmospheres pressure, there being maintained in the reacting mixture a small proportion of water vapour not exceeding 0.03 per cent by volume, the degree of hydrocracking being such that at least 15 per cent by volume of the reformed product boils below the lower cutting point of the hydrocarbon feed. The proportion of water vapour is conveniently controlled by drying the recycle hydrogen-rich gas to the necessary extent before actually recycling or adding water or a water-producing compound, such as isopropyl alcohol or a butanol, the water vapour content being adjusted to be less than 200 mg. per normal cubic metre of recycle gas. Drying of the recycle gas can be performed with a glycol or derivative thereof such as diethylene glycol, and further drying if necessary with a solid desiccant such as bauxite, activated alumina or silica gel. Temperatures may be between 470‹ and 510‹ C., pressures between 10 and 100 atm., and L.H.S.V. between 2 and 5 litres/litre of catalyst/hour. With a pressure below 30 atm., a molar ratio of hydrogen to hydrocarbon of more than 10 : 1 is preferred with a water vapour content of less than 0.02 per cent by volume. The catalyst may be 0.1 to 1 per cent by weight of platinum on alumina, silica-alumina, or silica-magnesia and may be activated by the addition of up to 1 per cent by weight of fluorine or chlorine.