Patent GB-600679-A (GB)
Title: Improvements in or relating to a process for the production of gasoline stocks
IPC: C10G59/04
Filed: 1945-08-02
Abstract: Highly aromatic gasoline stocks are produced by heating a C3-C4 hydrocarbon, admixing with a previously vaporized and heated naphtha, thermally cracking the mixture, separating the product into at least a C3-C4 hydrocarbon fraction, a light and a heavier gasoline fraction, recycling the C3-C4 fraction into the original C3-C4 hydrocarbon, catalytically cracking the heavier gasoline fraction with an aromatizing catalyst, separating a C3-C4 fraction and a gasoline fraction, and recycling the former.  The C3-C4 feed may be heated at 1000-1100 DEG  F. and 1500-2200 p.s.i. to give liquid products while a naphtha heated to 950-1050 DEG  F. is injected into the soaking coil containing the reactants.  The products are quenched and pass to a pressure separator and fractionator, C3-C4 being recycled, a light gasoline separated, and a heavier gasoline of 160-400 DEG  F. separated, pre-heated, mixed with steam and catalytically cracked at 1050-1200 DEG  F. and 50-250 p.s.i.  Alumina base catalysts, e.g. bauxite or synthetic alumina, with other metal oxides such as alkali or alkaline earth oxides or hydroxides may be used.  The products may be separated into C3-C4 for recycling or C4 and/or C5 which are alkylated with isoparaffin while a gasoline fraction may be worked up to recover benzene, toluene and aviation or motor fuel. In an example, the gas feed is 80-20 propane-butane mixture, and equal volumes of this and 100-400 DEG  F. naphtha of mixed straight-run and cracked stocks, on a liquid basis, are charged to the cracking stage.ALSO:Highly aromatic gasoline stocks are produced by heating a C3-C4 hydrocarbon, admixing with a previously vaporized and heated naphtha, thermally cracking the mixture, separating the product into at least a C3-C4 hydrocarbon fraction, a light and a heavier gasoline fraction, recycling the C3-C4 fraction into the original C3-C4 hydrocarbon, catalytically cracking the heavier gasoline fraction with an aromatizing catalyst, separating a C3-C4 fraction and a gasoline fraction, and recycling the former. The C3-C4 feed may be heated at 1000-1100 DEG  F. and 1500-2200 p.s.i. to give liquid products, while a naphtha heated to 950-1050 DEG  F. is injected into the soaking coil containing the reactants. The products are quenched and pass to a pressure separator and fractionator, C3-C4 being recycled, a light gasoline separated, and a heavier gasoline of 160-400 DEG  F. separated, preheated, mixed with steam and catalytically cracked at 1050-1200 DEG  F. and 50-250 p.s.i.  Alumina base catalyst, e.g. bauxite or synthetic alumina, with other metal oxides such as alkali or alkaline earth oxides or hydroxides may be used.  The products may be separated into C3-C4 for recycling or C4 and/or C5, which are alkylated with isoparaffins while a gasoline fraction may be worked up to recover benzene, toluene and aviation or motor fuel.  In an example, the gas feed is 80-20 propane-butane mixture, and equal volumes of this and 100-400 DEG  F. naphtha of mixed straight run and cracked stocks, on a liquid basis, are charged.