Performance of Ni/Si-pillared clay catalytic extrudates for benzene hydrogenation reaction

• Ni/Si–PILC systems are very active catalysts for benzene hydrogenation.
• Internal and external mass transfer limitations affect the catalyst performance.
• Apparent diffusivity of benzene increases exponentially with temperature.
• Apparent diffusivity of benzene presents a linear increase with catalyst porosity.

Ni supported on Si-pillared montmorillonite systems have been prepared and studied as catalysts for the test reaction of benzene hydrogenation. The Ni/Si-pillared clay catalytic systems were characterized as to their crystallographic structure, specific surface area, specific volume and apparent density. Their reactivity was evaluated over a temperature range of 70–150 °C under atmospheric pressure, in a differential bench scale reactor, and compared with other Ni catalysts supported on conventional carriers, such as γ-Al2O3 and Vycor. Apart from the intrinsic catalytic rates, the effect of both internal and external mass transfer limitations was also studied for particle sizes commonly used in industrial praxis. The change of the overall reaction rates with particle size was investigated. The mass transfer effects were examined for diluted catalytic beds of three extrudate sizes and diffusional limitation within the particles were decoupled from external mass transfer resistances. Particle diffusional limitations and their dependence on process temperature and particle porosity were determined and discussed.

Figure optionsDownload as PowerPoint slide