Process for recovering acetylene from hydrocarbons by thermal cracking

US5804689A · kind A · utility

Assignee

• Linde GmbH · DE

Inventors

• Nicole Schodel · Birkenfeld, DE
• Eberhard Lassmann · Pullach, DE
• Holger Hackner · Birkenfeld, DE

Key dates

• Filing date: Jan 30, 1996
• Grant date: Sep 8, 1998
• Expiry date: Jan 30, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C7/11
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

For recovering acetylene from hydrocarbons, the hydrocarbons are thermally cracked in the presence of CO.sub.2 as a diluent gas. Suitable for thermal cracking for acetylene generation is a ratio, by weight, of CO.sub.2 to hydrocarbon, of between 3:1 and 1:3, and preferably between 2:1 and 1:2. It is preferred for the CO.sub.2 to be mixed with the hydrocarbons before thermal cracking which is thereafter conducted at average reaction temperatures of between 800.degree. and 1200.degree. C., preferably between 900.degree. and 1100.degree. C. An average residence time of between 5 and 500 milliseconds (ms) of the hydrocarbons during thermal cracking has proven to be effective. As the hydrocarbon feedstock for the thermal cracking, basically C.sub.2+ alkanes, especially ethane, propane and/or butane, can be used advantageously. After the cracked gas is cooled, higher alkynes are removed from the cracked gas, then the acetylene is separated preferably by scrubbing with an absorption agent selective for acetylene. Recycle streams of hydrocarbons and/or CO.sub.2 for the thermal cracking can contribute to savings and more efficient use of the feedstock.