Solid effects on gas-liquid mass transfer in three-phase slurry catalytic hydrogenation of adiponitrile over raney nickel

✍ Scribed by C. Joly-Vuillemin; C. de Bellefon; H. Delmas

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 548 KB
• Volume: 51
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(96)00072-3

✦ Synopsis

Many three-phase catalytic reactions are limited by gas-liquid mass translbr. Pre'~aous works have round the transI~er rate to be increased by the presence of fine catalyst particles. Most of the studies concerned active carbon particles m aqueous media This paper inten&s to peint out and to explain flus efl;zct in the case of catalytic hydrogenation of adiponitrile over Ranev nickel particles. The experiments based on pressure variation due to the hydrogen absorption in a stirred batch reactor point out clearly an increase of kta at an optimum catalyst loading. This positive effect is reduced at high stirring speed and turns back to a small negative effect when using inert particles. The enhancement of gas-liquid mass transfer b 3 particles is maximum when a layer of water is physisorbed at the catalyst surface, The ~ater located at the solid surface could induce a better adhesion of the particles to the bubble. The total gas-liquid mass transt;zr could be enhanced when u~sing particles ~lth high hydrogen adsorption capability, by a"shuttle" or a"bridge" effect The solid particles act as hydrogen carriers rhese assumptions have been further supported by original experiments invol~ang the same equipment and measurements ~ ith a simultaneous reaction. A m~xiel which takes into account particles adhesion at the interlace has been set up and is in gt×xJ agreement with the experiments