Lebedev trial

The Lebedev process is one of Sergei Vasilievich Lebedev developed and in 1930 England and France patented process for the production of 1,3-butadiene by dehydrodimerization of ethanol .

Pure or mixed metal oxides such as MgO — SiO ₂ or Al ₂ O ₃ —SiO ₂ are used as catalysts . The oxides of aluminum , magnesium , iron or zirconium can be obtained, for example, by a precipitation reaction , for example by adding ammonia or ammonium carbonate to a solution of the corresponding nitrate . After shaping and calcination, these show good catalytic activity. The process is carried out at temperatures around 380 to 500 ° C.

The dehydration of ethanol to acetaldehyde is considered to be the first step in the reaction mechanism.

${\displaystyle \mathrm {C_{2}H_{5}OH\to \ CH_{3}CHO+H_{2}} }$

The acetaldehyde then dimerizes to crotonaldehyde with the release of water:

${\displaystyle \mathrm {2\ CH_{3}CHO\to CH_{3}CHCHCHO+H_{2}O} }$

Ethanol then reacts with the crotonaldehyde to form 1,3-butadiene, acetaldehyde and water.

${\displaystyle \mathrm {C_{2}H_{5}OH+CH_{3}CHCHCHO\to CH_{2}CHCHCH_{2}+CH_{3}CHO+H_{2}O} }$

The process is currently of no industrial importance.

Individual evidence

1. ↑ Boy Cornils , Wolfgang A. Herrmann , Chi-Huey Wong, Horst-Werner Zanthoff: Catalysis from A to Z: A Concise Encyclopedia . Verlag Wiley-VCH, 2012, ISBN 3-527-33307-X , p. 337.
2. ↑ SK Bhattacharyya, ND Ganguly: One-step catalytic conversion of ethanol to butadiene in the fixed bed. I. Single-oxide catalysts. In: Journal of Applied Chemistry. 12, 1962, pp. 97-104, doi : 10.1002 / jctb.5010120301 .
3. ^ WJ Toussaint, JT Dunn, DR Jackson: Production of Butadiene from Alcohol. In: Industrial & Engineering Chemistry. 39, 1947, pp. 120-125, doi : 10.1021 / ie50446a010 .