Measurement of Mass Transfer Coefficients

These equations contain only one unknown parameter, kiAi. Assume values for it and solve Equations 11.20 and 11.21 simultaneously. Compare the calculated results to the experimental measurements using nonlinear least-squares analysis as in Equation 

This is the preferred modern approach, but the precomputer literature relied on computationally simpler methods for fitting kiAi. 

Equations 11.20 and 11.21 are linear, first-order ODEs with coefficients that are assumed constant. The equations can be combined to give a second-order ODE in af. 

This equation can be used to estimate ki Ai from an experimental ai(t) curve in at least three ways  

This method is reasonable in terms of accuracy and allows brief experiments. 

The inflection point method At the inflection point, d afidfi = 0 and 

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Data of heat transfer between particle and fluid usually arc not measured directly because of the experimental difficulties, but are deduced from measurements of mass transfer coefficients assuming the Colburn analogy to apply,... 

Simultaneous Measurement of Mass-Transfer Coefficients and Intetfacial Area... 

Andre, G., Moo-Young, M., and Robinson, C.W. (1981), Improved method for the dynamic measurement of mass transfer coefficient for application to solid-substrate fermentation, Biotechnology and Bioengineering, 23(7) 1611-1622. 

Blazej, M., Jurascik, M., Annus, J., and Markos, J. (2004b), Measurement of mass transfer coefficient in an airlift reactor with internal loop using coalescent and non-coalescent liquid media, Journal of Chemical Technology Biotechnology, 79(12) 1405-1411. 

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