Polymer-Filled Composite Porous Catalytic Particles for Hydrodynamic Studies in Trickle-Bed Reactors

Abstract

A simple and scaleable method is proposed for suppressing internal porosity in various porous particles that are widely applied in packed-bed catalytic systems. The method is based on a complete filling of the pores by a cross-linked organic polymer. The particles were first loaded with the volume of organic monomer and cross-linker needed to achieve complete blockage of the porosity, and subsequently, in situ radical polymerization was performed with heating under reduced atmosphere. The method is shown to be adaptable for particles of various shapes, sizes, and porous structures. Selective and complete pore filling has been confirmed by nitrogen physisorption measurements, thermogravimetric analysis, and scanning electron microscopy. The different analyses confirm uniform pore blocking. The difference in contact angle before and after polymer impregnation was found to be negligible. The system is especially suitable for packed-bed hydrodynamic studies to disentangle extragranular hydrodynamic effects (such as axial dispersion) from intraparticle mass transfer effects, which are key to scaling down/up trickle-bed reactors. The liquid holdup and Péclet number for a trickle-bed reactor packed with polymer-impregnated spherical particles and glass beads, respectively, were compared for the compatibility of the method. For given superficial liquid and gas velocities corresponding to the pulsing flow regime, the external liquid holdup and Péclet number were found to be correspondingly close for both particles.

Liquid holdup and wetting efficiency in a rotating trickle‐bed reactor

“…However, CT scan failed to distinguish the external liquid holdup of alumina spheres. Aydin et al performed hydrodynamic studies in TBR packed with spheres of different contact angles, and found that the external liquid holdup was pretty close. This inspired us to replace the external static liquid holdup of alumina spheres with that of the glass spheres.…”

Reaktoren für Dreiphasen-Reaktionen: Rieselbettreaktoren

“…Das Vermischungsverhalten in Rieselbettreaktoren kann anhand der Verweilzeitverteilung geeigneter inerter Tracer charakterisiert werden und wird nachfolgend hauptsächlich für die Flüssigphase beschrieben. Am gebräuchlichsten ist die Verwendung inerter löslicher Tracer wie beispielsweise Salze oder mischbare Substanzen mit von der Flüssigphase abweichenden und detektierbaren physikochemischen Eigenschaften (Härting et al 2015c;Aydin et al 2008;Hamidipour et al 2009).…”

“…bei dem die Abweichung von der idealen Propfenströmung durch den axialen Dispersionskoeffizienten quantifiziert wird. Bei porösen Partikeln muss der intrapartikuläre Stofftransport zusätzlich berücksichtigt werden (Aydin et al 2008…”

Modelling of hydrodesulphurization in industrial trickle bed reactor using mixing cell network approach

“…Hydroprocessing forms an essential unit process of petroleum refining to meet product specifications of prescribed limits of sulphur, aromatics, nitrogen, and olefins, as per environmental norms. [ 1–4 ] Hydroprocessing entails hydrotreating, which involves removing hetero compounds like sulphur, nitrogen, and oxygen, and saturation of aromatic rings and olefins. It also involves processes like hydrocracking, which disintegrates feed with high molecular weight into low molecular weight products.…”