Mass-transfer operations classification

This classification is not exhaustive but it does categorize all the major mass-transfer operations. Indeed, new operations continue to be developed. 

Estimation of the mass-transfer coefficients associated with columnar operation, at least for the discrete bubble phase we are considering, is the same in practice as for tank-type reactors. Thus, one determines the value of the diffusion time by equation (8-207) and goes on to the calculation of for the appropriate eonditions as defined in the classification of Astarita. 

Many of these unit operations have certain fundamental and basic principles or mechanisms in common. For example, the mechanism of diffusion or mass transfer occurs in drying, membrane separation, absorption, distillation, and crystallization. Heat transfer occurs in drying, distillaticti, evaporation, and so on. Hence, the following classification of a more fundamental nature is often made into transfer or transport processes. 

Classification of the separation techniques according to those involving phase change or mass transfer from one phase to another, known as diffusional operations, and those that are useful in the separation of solid particles or drops of a liquid and that are generally based in the application of an external physical force, known as mechanical separations. 

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