Solution of the Transient Gas-Phase Diffusion Problem Equations

APPENDIX 12 SOLUTION OF THE TRANSIENT GAS-PHASE DIFFUSION PROBLEM EQUATIONS (12.4M12.7) 

We can solve this problem by Laplace or similarity transforms. Let us use the latter. Let 

Then the total quantity of A that has been transferred into the particle from t = 0 to t is 

1a Consider the growth of a particle of dibutyl phthalate (DBP) in air at 298 K containing DBP at a background mole fraction of 0.10. The vapor pressure of DBP is sufficiently low that it may be assumed to be negligible. 

2b In Problem 12.1 for the purpose of computing the mass and energy transport rates to the particle it was assumed that continuum conditions held. 

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