Phenomenological approach to understand the behavior of trickle bed reactors with liquid flow modulation.

M. ALEJANDRA AYUDE; MIRYAN C. CASSANELLO; PATRICIA M. HAURE; OSVALDO M. MARTINEZ

Praga, República Checa

Congreso; 16th. International Congress of Chemical and Process Engineering (CHISA); 2004

Czech Society of Chemical Engineering

Cyclic operation of trickle bed reactors clearly results in better reactor performance forhighly exothermic reactions with strong external mass transfer limitations (Drinkenburg, 2002;Castellari and Haure, 1995). Although, significant conversion enhancement has also beenobserved even for isothermal processes occurring with strong internal limitations, in the case ofgaseous reactant limited reactions (Fraguío et al., 2004; Lange et al., 1994). The possibility ofperformance enhancement or decline while modulating the flow arises from the competitionbetween phases in supplying reactants to the catalyst; then, a detailed analysis of reactantprofiles inside the catalytic particle would help understanding the outcome of this complexphenomenon. Hence, present work has the purpose of modeling the time course of the reactionrate for a catalyst particle that is immersed in an alternating ON-OFF liquid flow in order to getfurther insights in the outgoing of the transient three-phase process. Qualitative trends predictedby the model are compared to reported experimental results and, when critical limits areevidenced, new definitions are proposed.