Qualitative Observations of Heat and Mass Transfer Effects on the Behaviour of a Trickle Bed Reactor

Dynamic effects of vaporization with exothermic reaction in a porous catalytic pellet

“…Thus, with all conditions equal, vaporization and associated thermal effects are expected to be more pronounced with the hydrogenation of cyclohexene compared to that of AMS. The importance of vaporization during this reaction has been demonstrated by Hanika and coworkers in several reactor studies (Hanika et al, 1974(Hanika et al, , 1975(Hanika et al, , 1976Stanek and Hanika, 1982;Lange et al, 1990). In the current study, a direct comparison of cyclohexene to AMS hydrogenations under dynamic conditions helps to elucidate the impact of phase transitions.…”

Partial internal wetting of catalyst particles: Hysteresis effects

“…This is the case despite several experimental studies reporting the existence of partial internal wetting and associated hysteresis effects (Sedriks and Kenney, 1973;Satterfield and Ozel, 1973;Hanika et al, 1975Hanika et al, , 1976Kim and Kim, 1981a,b). Unusual and complex behavior arising from vapor-liquid transition in trickle beds has also been observed by various investigators (Hanika et al, 1975(Hanika et al, , 1976Satterfield and Way, 1972;Germain et al, 1974;Eigenberger and Wegerle, 1982;Tukac et al, 1986), making it all the more imperative that the physical processes affecting such systems be more thoroughly examined.…”

Hysteresis and Phase Transitions in a Single Partially Internally Wetted Catalyst Pellet: Thermogravimetric Studies

“…In the latter case partial internal wetting of the catalyst pore structure can also result, leading to additional intricacies and intriguing behavior. When manifested in their simplest form these complexities display themselves as evaporation-condensation transitions between completely wetted and completely dry catalyst, as exemplified by the now classical studies of Hanika et al (1975Hanika et al ( , 1976. These investigators, in their experiments with cyclohexene hydrogenation over a bed of supported palladium catalyst particles, showed that the liquid mixture in the trickle bed reactor could evaporate under suitable conditions, thereby leading to sharp increase in reaction rate.…”