Process for preparing acetylene by the Sachsse-Bartholomé process

摘要

A process is proposed for preparing acetylene by the Sachsse-Bartholomé process by combustion of a natural gas/oxygen mixture in one or more burners to obtain a cracking gas which is cooled in two or more stages in burner columns, each burner having one or more burner columns assigned thereto, and said cracking gas being quenched with pyrolysis oil in the first cooling stage, to obtain a low boiler fraction comprising benzene, toluene and xylene from the one or more burner columns, which is cooled with direct cooling water and separated in a phase separator into an aqueous phase and an organic phase which comprises benzene, toluene and xylene and is fully or partly introduced to the top of the one or more burner columns as a return stream, wherein the organic phase comprising benzene, toluene and xylene from the phase separator, prior to full or partial recycling to the top of the one or more burner columns, is supplied to a selective hydrogenation over a catalyst which comprises at least one platinum group metal on an inorganic metal oxide as support, comprising 0.05 to 5% by weight of platinum group metal, based on the total weight of the catalyst, and wherein the selective hydrogenation is performed at a pressure in the range from 10 to 70 bar gauge and a temperature in the range from 0 to 100° C.

主权项

1. A process for preparing acetylene by the Sachsse-Bartholomé process by burning a natural gas/oxygen mixture in one or more burners to obtain a cracking gas which is cooled in two or more stages in burner columns, each burner having one or more burner columns assigned thereto, and said cracking gas being quenched with pyrolysis oil in the first cooling stage, to obtain a low boiler fraction comprising styrene, indene, benzene, toluene and xylenes from the one or more burner columns, which is cooled with direct cooling water and separated in a phase separator into an aqueous phase and an organic phase which consists of:
8 to 18% by weight of styrene; 5 to 10% by weight of indene, a total of 15 to 20% by weight of the sum of ortho-, para- and meta-xylene, 15 to 20% by weight of toluene and 8 to 10% by weight of benzene, where the sum of all components adds up to 100% by weight;and is introduced to the top of the one or more burner columns as a return stream, and recovering acetylene;wherein the organic phase consisting of styrene, indene, benzene, toluene and xylenes from the phase separator is supplied to a selective hydrogenation over a catalyst which comprises at least one platinum group metal on an inorganic metal oxide as support, comprising 0.05 to 5% by weight of platinum group metal, based on the total weight of the catalyst, and wherein the selective hydrogenation is performed at a pressure in the range from 1 to 40 bar and a temperature in the range from 25 to 150° C. to selectively hydrogenate styrene, indene and derivatives thereof while preserving the aromatic rings, such that the selective hydrogenation of indene proceeds at a conversion of >96%.