Influence of Process Parameters on the Reaction Kinetics of the Chromium‐Catalyzed Trimerization of Ethylene |
| |
| Authors: | Anina Wöhl Dr Wolfgang Müller Dr Stephan Peitz Normen Peulecke Dr Bhaskar R Aluri Dr Bernd H Müller Dr Detlef Heller Dr Uwe Rosenthal Prof Dr Mohammed H Al‐Hazmi Dr Fuad M Mosa |
| |
| Institution: | 1. Linde AG, Linde Engineering Division, Dr.‐Carl‐von‐Linde‐Strasse 6–14, 82049 Pullach (Germany), Fax: (+49)?89‐744454981;2. Leibniz‐Institut für Katalyse an der Universit?t Rostock e.V. Albert‐Einstein‐Strasse 29A, 18059 Rostock (Germany), Fax: (+49)?381‐128151176;3. Saudi Basic Industries Corporation, P.O. Box 42503, Riyadh 11551 (Saudi Arabia) |
| |
| Abstract: | In this paper we report the results of an extensive experimental kinetic study carried out on the novel ethylene trimerization catalyst system, comprising the chromium source CrCl3(thf)3] (thf=tetrahydrofuran), a Ph2P‐N(iPr)‐P(Ph)‐N(iPr)H (PNPNH) ligand (Ph=phenyl, iPr=isopropyl), and triethylaluminum (AlEt3) as activator. It could be shown that the initial activity shows a first‐order dependency on the ethylene concentration. Also, a first‐order dependency was found for the catalyst concentration. The initial activity follows a typical Arrhenius behavior with an experimentally determined activation energy of 52.6 kJ mol?1. At elevated temperatures (ca. 80 °C), a significant deactivation was observed, which can be tentatively traced back to a ligand rearrangement in the presence of AlEt3. After a fast initial phase, a pronounced ‘kink’ in the ethylene‐uptake curve is observed, followed by a slow, almost linear, further increase of the total ethylene consumption. The catalyst composition, in particular the ligand/chromium and the cocatalyst/chromium molar ratio, has a strong impact on the catalytic performance of the trimerization of ethylene. |
| |
| Keywords: | chromium homogeneous catalysis kinetics N P ligands oligomerization |
|
|
