Multiphase Bioreactor Design

If the same normalised residence time is assumed in both reactors, τpfr=τcstr, then:

(60)

The conversions obtained in both reactors are presented in Figure 7.6. It can be seen that
the PFR leads to higher conversions being-much more efficient, assuming the reactors are
operated at ideal conditions.

Figure 7.6 Efficiency of the CSTR

compared with PFR. The dotted line

applies to a zero order reaction

whereas the continuous line refers to a

first order reaction.

Operational stability

To evaluate the enzymatic deactivation in MBR, and due to its similarities with a CSTR
performing a first order reaction, Equation 55 was modified to include a deactivation
constant, considering a first order activity decay:

(61)

The enzyme deactivation was evaluated using the relation of enzymatic activities (E/E 0 )
at initial time (ti) and at final time (tf) after the steady-state conditions were reached in
MBR. The activities were plotted against the time of operation (see Figure 7.7).

(62)

Multiphase bioreactor design 222