Reactor engineering, fluidized reactors

Part III Beyond the Fundamentals presents material not commonly covered in textbooks, addressing aspects of reactors involving more than one phase. It discusses solid catalyzed fluid-phase reactions in fixed-bed and fluidized-bed reactors, gas-solid noncatalytic reactions, reactions involving at least one liquid phase (gas-liquid and liquid-liquid), and multiphase reactions. This section also describes membrane-assisted reactor engineering, combo reactors, homogeneous catalysis, and phase-transfer catalysis. The final chapter provides a perspective on future trends in reaction engineering. 

Jones, A.G., Wachi, S. and Delannoy, C.C., 1992b. Precipitation of calcium carbonate in a fluidised bed reactor. In Fluidization VII. Eds. O.E. Potter and D.J. Nicklin, New York Engineering Foundation, pp. 407M14. 

A more recent review by Fahidy (FI) concerns the chemical engineering approach to electrochemical processes, such as fluidized-bed reactors, bipolar particulate reactors, pulsed electrochemical reactors, gas-phase electrochemical reactors, electrocrystallization and electrodissolution, and the enhancement of heat and mass transfer in electric fields. In this review, the author also discusses dimensionless mass-transfer equations applied in cell design. Such equations are reviewed in greater detail in Section VI. 

The available models mostly refer to ideal reactors, STR, CSTR, continuous PFR. The extension of these models to real reactors should take into account the hydrodynamics of the vessel, expressed in terms of residence time distribution and mixing state. The deviation of the real behavior from the ideal reactors may strongly affect the performance of the process. Liquid bypass - which is likely to occur in fluidized beds or unevenly packed beds - and reactor dead zones - due to local clogging or non-uniform liquid distribution - may be responsible for the drastic reduction of the expected conversion. The reader may refer to chemical reactor engineering textbooks [51, 57] for additional details. 

This is no place to review the literature, but the later volume Fluidization (Academic Press, 1971) which Davidson and Harrison edited deserves mention, as do chapters 10 and 11 (by Davidson, Harrison, Darton and La Nauze, and Amundson, Bukur and Caram, resp.) in Chemical Reactor Theory (Prentice-Hall, Englewood Cliffs. 1977) D. Kunii and O. Levenspeil Fluidization Engineering (Wiley, New York. 1969) and P. N. Rowe and J. G. Yates Fluidized Bed Reactors (chap. 7 of Chemical Reaction and Reactor Engineering. Ed. J. J. Caiberry and A. Varma. Marcel Dekker, New York. 1987). 

The symposium upon which this volume is based focused on three areas in reaction engineering fluidized bed reactors, bubble column reactors, and packed bed reactors. Each area comprises a section of this book. Professor J. R. Grace chaired and coordinated the fluidized bed sessions Professors Y. T. Shah and A. Bishop, the bubble column reactor session and Professor A. Varma, the packed bed reactor session. Each section in this book opens with a brief review chapter by the session chairman that includes an overview of the chapters in each session. 

---