Question

“Increasing the bulk concentration of substrate CAb”, is included in which parameter?

(a) Internal mass-transfer

(b) External mass-transfer

(c) Internal-External mass- transfer

(d) Heat transfer

This question was addressed to me in a job interview.

I need to ask this question from Minimising Mass Transfer Effects in division Heterogenous Reactions of Bioprocess Engineering

Answer 1

Correct option is (b) External mass-transfer

For explanation: External mass transfer is more rapid at high bulk substrate concentrations; the higher the concentration, the greater is the driving force for mass transfer across the boundary layer.