HYDRODYNAMICS OF TRICKLE BED REACTORS Steady- and Nonsteady-State Operations

Trickle bed reactor (TBR) is one of the most widely used three-phase reactors in various processes mostly operated at high temperature and high pressure. The ongoing experimental work on the hydrodynamic parameters (flow regime transition, pressure drop, liquid holdup, wetting efficiency etc.) of this packed bed reactor configuration goes to early 1960’s. Different techniques were applied by different researchers for the measurement of these hydrodynamic parameters which let the comparison and the decision of more convenient method by means of doing investigations at conditions near to that of industrial processes. Process intensification is considered to be a leading approach for the ongoing research on the economic reduction and reactor efficiency enhancement. Artificial induction of pulses is pronounced as one of the methods for the process intensification in TBRs. As trickle bed reactor is also used in biochemical processes, and the initial liquid behaving like a Newtonian fluid could turn into a non-Newtonian fluid after various biochemical processes; it is emphatic to study TBR hydrodynamics with non-Newtonian systems. Despite large amount of work exists in the literature for steady state hydrodynamics of TBR operating at high pressure; the hydrodynamic behavior of TBR at high temperature has been left as a concealed issue. Additionally none of the experimental work performed to demonstrate the advantages of periodic operation on TBR hydrodynamics dealt with the effects of increased temperature and pressure. This study illustrates the hydrodynamics of TBR at increased temperature and pressure under constant throughput flow and cyclic operation. Foreword This PhD thesis comprises eight chapters. Each chapter represents an article published, accepted or submitted in the scientific journals. These articles are listed below. [1] Aydin, B. , Larachi, F. Trickle bed hydrodynamics and flow regime transition at elevated temperature for a Newtonian and a non-Newtonian liquid. Chemical Engineering Science, 60, 6687-6701, 2005 [2] Aydin, B. , Fries, D. , Lange, R. , Larachi, F. Slow-mode induced pulsing in trickle-bed reactors at elevated temperature. AIChE Journal, 52, 3891-3901, 2006 [3] Aydin, B. , Fries, D. , Lange, R. , Larachi, F. Slow-mode induced pulsing in trickle beds at elevated temperature for (non-)Newtonian liquids. Chemical Engineering Science, 62, 5554-5557, 2007 [4] Aydin, B. , Larachi, F. Flow regime transition and hydrodynamics of slow-mode liquidinduced pulsing at elevated temperature for (non-)Newtonian liquids. Chemical Engineering Science, accepted [5] Aydin, B. , Cassanello, M.C. , Larachi, F. Influence of temperature on fast-mode cyclic operation hydrodynamics in trickle-bed reactors. Chemical Engineering Science, 63, 141152, 2008 [6] Aydin, B. ; Larachi, F. Trickle bed hydrodynamics at elevated temperature for (non-) Newtonian foaming liquids. Chemical Engineering Journal, submitted [7] Aydin, B. , Hamidipour, M. , Larachi, F. Fast-mode alternating cyclic operation in trickle beds at elevated temperature for foaming systems. Chemical Engineering Science, 62, 7539-7547, 2007 [8] Aydin, B. , Bilodeau, S. , Hamidipour, M. , Larachi, F. , Kleitz, F. Polymer-filled composite porous catalytic particles for hydrodynamic studies in trickle bed reactors. Industrial and Engineering Chemistry Research, submitted