Diagnosing mass transfer limitations involves several approaches:
Weisz-Prater Criterion: A dimensionless number used to determine the significance of internal diffusion limitations. If the criterion is much less than one, internal mass transfer is not limiting. Thiele Modulus: Another dimensionless number that compares the rate of reaction to the rate of diffusion within the pores of the catalyst. Higher values indicate significant diffusion limitations. Experimental Techniques: Techniques such as varying the particle size, changing the flow rate, or using isotopic tracers can provide insights into the presence of mass transfer limitations. Computational Modeling: Advanced simulation tools can model mass transfer and reaction kinetics, offering detailed insights into the limitations and potential solutions.
