Uc=1.29 cm/s, Ud=0.91 cm/s, εs=0.32,
εo=0.0925; Xvmax=0.01 mol/m
3s,
m=100
Figure 12.12 Profile of substrate (12a)
and product (12b) concentration in the
medium phase at different fluxes of the
organic phase. Profile of product
concentration in the organic phase
(12c) at different fluxes of the organic
phase.
Uc=1.49 cm/s, Xvmax=0.01 mol/m^3 s,
m=100, Ctoxp=100 mol/m^3. Ud=0.14
cm/s, εs=0.30, εo=0.01 Ud=0.36cm/s,
εs=0.27, εo=0.036; Ud=0.75 cm/s,
εs=0.26, εo=0.069.
So, the total amount of moles of product produced is equal to the toxic
product concentration multiplied by the total reactor volume. In order to
compare a three-phase fluidised bed with a two-phase fluidised bed we
calculated the time necessary to reach 99% of the total amount that can be
converted in a two-phase fluidised bed. Obviously, there is a lot of
freedom in totally or partly recirculating the organic solvent in the three-
phase fluidised-bed bioreactor, see Figure 12.2. In this strategy we used a
total reflux as a fair comparison. An economic evaluation must show
whether a total reflux yields the lowest cost, but this is not the topic of this
chapter.Comments on operating the bioreactor continuously may be found at the end of this
chapter.
Batch OperationMultiphase bioreactor design 372