Alkylation of benzene

摘要

1,178,952. Detergent alkylate; dehydrogenating n-paraffins. UNIVERSAL OIL PRODUCTS CO. 19 March, 1968 [23 March, 1967], No. 13188/68. Heading C5E. Alkylbenzenes are produced by a process comprising the steps of: (a) reacting benzene with an olefinic feed in a first zone at 4-49‹ C. and in the presence of a mineral acid catalyst; (b) separating the effluent into a first catalyst phase and a first hydrocarbon phase, the latter including at least some unreacted olefinic feed; (c) recycling at least part of said first catalyst phase to said first zone; (d) passing said first hydrocarbon phase to a second reaction zone maintained at a temperature at least 3À6‹ C. higher than in the first zone, preferably in the range 27-66‹ C., and therein effecting further reaction in the presence of fresh acid catalyst (either new or regenerated); (e) separating from the second zone effluent a second catalyst phase and a second hydrocarbon phase; (f) recycling at least part of said second catalyst phase to the first reaction zone (the remainder, if any, may be recycled to the second zone); and (g) recovering desired product from said second hydrocarbon phase. At least part of the first catalyst phase may be regenerated and returned to the second zone as fresh catalyst. The olefins are suitably C 10-15 linear mono-olefins prepared by dehydrogenation of corresponding n-paraffins, e.g. in the presence of a catalyst comprising a neutral oxide of a Group VI element or an oxide and/or sulphide of a Group VIII metal, particularly Pt/Al 2 O 3 or Pd/Al 2 O 3 . Water (e.g. 2000 ppm.) is preferably present during said dehydrogenation. The detergent alkylate products are practically colourless and substantially free of olefinic contaminants.