mass transfer in multiphase systems - Greenleaf University

MASS TRANSFER IN MULTIPHASE SYSTEMS: VOLATILE ORGANIC COMPOUND
REMOVAL IN THREE-PHASE SYSTEMS
35000
30000
System 1 Solid VOC Concentration vs Time
Models
X, ppb
25000
20000
15000
10000
5000
X data
ln(X) vs t1/2
X vs ln(t)
Model ln(X) vs 1/t1/2
Model ln(t)
0
0 20 40 60 80
Time, hr
Figure 12. Laboratory data with two models.
The scale-up was based on the ln(X) vs. t -1/2 curve although the X vs. ln(t) curve would
also be acceptable. Once having a good model that represents the data, the scale-up is performed
to determine either 1) the time required to operate based on a specified flow rate or 2) the flow
rate required for a time requirement. Based on this, the change in the mass concentration is:
dX
dt
Ko
kD
K
X 1
t H t
'
o
X
(38)
The plan is to find the K o from the laboratory and scale it up to an operating system using the
Sherwood number (Sh) for the system that had laboratory testing (Treybal 1987).
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