Page 434 - Elements of Chemical Reaction Engineering Ebook

Sec. 7.5 Bioreactors 4Q5

Bedfum
E!eservoir Rotameter

AIr
Fermentor
Figure 7-16 @hemostat system.

and is simply the reciprocal of the space time z. Dividing Equations (7-1 17)
and (7-1 18) by V and using the definition of the dilution rate, we have
accumulation = in - out + generation

CSTR mass
balances (7- 123)

Substrate: dCS - DC, - DC, + r, (7-124)
=
dt
Using the Monod equation, the growth rate is determined to be

rg = PC, (7-100)
where

(7-101)

For steady-state operation we have
DC, = rg - r, (7-125)
and
wcso - C,) = rs (7 - 126)
We now neglect the death rate, r,, and combine Equations (7-100) and
(7-125) for steady-state operation to obtain the mass flow rate of cells out of
the system, rh ~.

ri = C,u, = rgV = kC,V (7 - 1 27)

After we divide by C,V,
Dilution rate (7-128)