GB1474491A - Texaco dev corp alkylation process - Google Patents

Abstract

1474491 Alkylating isobutane with ethylene TEXACO DEVELOPMENT CORP 31 Jan 1975 4240/75 Heading C5E In an aluminium chloride catalysed alkylation process wherein isobutane and ethylene are contacted with an aluminium chloridehydrocarbon complex catalyst and ethyl chloride in an alkylation reaction zone in the liquid phase, under alkylating conditions, and with agitation sufficient to form an emulsion of reactant hydrocarbons and catalyst, wherein ethylene charge to said process contains C 1 -C 3 range normal paraffin diluents, wherein fresh isobutane charge to said process contains C 3 - C 4 range normal paraffin diluents and impurities which are reactive with aluminium chloride; the procedure comprises: (a) reacting, in an alkylation reaction zone, an isobutane stream substantially free of normal paraffin hydrocarbons and impurities which are reactive with aluminium chloride with an ethylene stream containing C 1 -C 3 normal paraffin impurities in the presence of an aluminium chloridehydrocarbon complex catalyst and hydrogen chloride catalyst activator for production of alkylated hydrocarbons; (b) separating, in a product separation zone, the reaction effluent from said alkylation reactionzone into a hydrocarbon phase essentially free of aluminium chloride-hydrocarbon complex catalyst and a catalyst phase; (c) recycling a major portion of said catalyst phase from product separation zone to said alkylation reaction zone for said reacting step a; (d) fractionating, in a debutanizing zone, hydrocarbon phase into a C 5 and heavier alkylated hydrocarbon product fraction and a recycle hydrocarbon fraction comprising isobutane with minor amount of ethyl chloride, C 1 -C 4 normal paraffin hydrocarbons and unreacted ethylene; (e) recycling a major portion of said recycle hydrocarbon fraction to said alkylation reaction zone for reaction of said isobutane with said unreacted ethylene in step (a); (f) contacting, in a contacting zone, a minor portion of said catalyst phase from said product separation zone with said fresh isobutane charge containing C 3 -C 4 range normal paraffin diluents and impurities which are reactive with aluminium chloride for conversion of said reactive impurities into compounds soluble in said catalyst phase; (g) separating, in a separation zone, the effluent from said contacting zone into a catalyst phase containing conversion products of said reactive impurities from said fresh isobutane charge and an isobutane phase containing C 3 -C 4 normal paraffin impurities and substantially free of said reactive impurities; (h) fractionating, in a depropanizing zone, the isobutane phase from said separation zone and a minor portion of said recycle hydrocarbon fraction from said debutanizing zone into a C 1 -C 3 fraction comprising C 1 -C 3 normal paraffins and a minor portion of said unreacted ethylene and a depropanizing zone bottoms fraction comprising a major portion of isobutane and minor amounts of normal butane and ethyl chloride; (i) fractionating, in a deisobutanizing zone, said depropanizing zone bottoms fraction into a butane fraction comprising normal butane and ethyl chloride and an isobutane fraction substantially free of C 1 -C 4 normal paraffin diluents and said reactive impurities; and (j) charging said isobutane fraction from said deisobutanizing zone to said alkylation reaction zone as the isobutane stream of step (a).