GB827367A - Process for upgrading petroleum naphtha distillates - Google Patents

Abstract

Petroleum distillates boiling in the range of from 175-500 DEG F and having a boiling point range of at least 100 DEG F. are upgraded by fractionally distilling to obtain at least 2 fractions each having an appreciable boiling point range, separately contacting each of the fractions in the presence of hydrogen and at a temperature above 700 DEG F. and a pressure above 500 p.s.i.g. with a catalyst comprising a hydrogenating component disposed on an active acid cracking catalyst support fractionally distilling each of the resulting reaction product streams to separate each stream into an overhead fraction boiling essentially below the initial boiling point of the feed fraction and a bottom fraction, and blending the overhead fractions to produce a high octane gasoline. The bottom fraction may be recycled by blending with fresh feed. The preferred catalyst is coprecipitated molybdenaalumina combined with cobalt oxide containing 2% cobalt and 7% molybdenum, although any oxide and sulphide of Group VI and VIII such as those of molybdenum, tungsten, vanadium, chromium, iron, nickel and cobalt supported on alumina, silica-alumina, silica-magnesia, silica-alumina-zirconia and clays may be used. In a specific example, a naphtha feed stream having a boiling point range of 180-430 DEG F. is divided into 5 fractions and each passed at the rate of 2V/V/hour at 800 DEG F. and 1200 p.s.i.g. with 6000 standard cubic feet of hydrogen per barrel of feed through a catalyst comprising 1% of molybdenum oxide on a silica-alumina cracking catalyst. Each fraction was then refractionated to recover the part boiling below the initial boiling point of the particular naphtha cut involved, with the bottoms then being recycled back through the reaction zone together with added feed and fresh as well as recycled hydrogen.ALSO:Petroleum distillates boiling in the range of from 175-500 DEG F and having a boiling-point range of at least 100 DEG F. are upgraded by fractionally distilling to obtain at least 2 fractions each having an appreciable boiling-point range, separately contacting each of the fractions in the presence of hydrogen and at a temperature above 700 DEG F. and a pressure above 500 p.s.i.g. with a catalyst comprising a hydrogenating component disposed on an active acid cracking catalyst support, fractionally distilling each of the resulting reaction product streams to separate each stream into an overhead fraction boiling essentially below the initial boiling-point of the feed fraction and a bottom fraction, and blending the overhead fractions to produce a high octane gasoline. The bottom fraction may be recycled by blending with fresh feed. The preferred catalyst is coprecipitated molybdena-alumina combined with cobalt oxide containing 2% cobalt and 7% molybdenum, although any oxide and sulphide of Group VI and VIII such as those of molybdenum, tungsten, vanadium, chromium, iron, nickel and cobalt supported on alumina, silica-alumina, silica-magnesia, silica-alumina-zirconia and clays may be used. In a specific example, a naphtha feed stream having a boiling-point range of 180-430 DEG F. is divided into 5 fractions and each passed at the rate of 2 v./v./hour at 800 DEG F. and 1200 p.s.i.g. with 6000 standard cubic feet of hydrogen per barrel of feed through a catalyst comprising 1% of molybdenum oxide on a silica-alumina cracking catalyst. Each fraction was then refractionated to recover the part boiling below the initial boiling-point of the particular naphtha cut involved, with the bottoms then being recycled back through the reaction zone together with added feed and fresh as well as recycled hydrogen.