Transport Phenomena in Gas-Liquid-Particle Operations

A comparison of the operations discussed in Section III with regard to applications in a particular chemical process should be based, at least in part, on the analysis of a theoretical model of the type discussed in Section IV. At the present stage of development, only an approximate estimate of reaction conversion and selectivity will be obtained in this way, and the analysis must in most cases be supplemented with qualitative considerations. The analysis is necessary, however, if optimum choice of operation and optimum design of the chosen operation are to be achieved. 

The use of even the very simple models for isothermal operation described in Section IV,B requires a substantial amount of information regarding the elementary iate processes occurring in a gas-liquid-particle operation, as discussed in Section IV,A. While a considerable amount of information of this kind is available in the chemical engineering literature, it is widely scattered. It will be attempted in this section to present a comprehensive review of this information in order to facilitate its use. It is hoped that this review will be of value not only to those chemical engineers directly interested in the practical applications of gas-liquid-particle operations, but also, by pointing to the several areas characterized by very limited information, to those interested in research in this field. 

The experimental and theoretical work reported in the literature will be reviewed for each of the five major types of ga s-liquid-particle operation under the headings Mass transfer across gas-liquid interface mass transfer across liquid-solid interface holdup and axial dispersion of gas phase holdup and axial dispersion of liquid phase heat transfer reaction kinetics. 

Trickle-flow operation is probably the most widely used operation for large-scale industrial gas-liquid-particle processes. It has been the subject of a large number of investigations, and is, as a result, relatively well described. 

It may be noted that trickle-flow operations is not always clearly distinguished in the literature from fixed-bed bubble-flow operation. The two 

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