Performance of the CSTR with Complex Kinetics

Modifications of biokinetic models can be included in the CSTR performance equation. 

Modifications have been introduced to deal with the discrepancy between model behavior and chemostat experiments. Including the specific lysis rate /Cd and the maintenance coefficient (cf. Equs. 5.80 and 5.76), the enlarged model is 

lysis as well as maintenance may cause the curve of biomass concentration against the dilution rate D to approach zero as the dilution rate tends to zero (see Figs. 6.4 and 6.5). Furthermore, the lysis causes a decrease in the washout point 

The specific lysis rate can be determined by the analysis of batch experiments, but the maintenance coefficient cannot be so determined. The estimation of this coefficient is possible by analysis of chemostat experiments. The theoretical basis for this is given with Equ. 6.20. According to this relation, the plot of the quotient (sq — 5)/x versus the reciprocal dilution rate 1/D gives a straight line  

We call the quotient x/ sq — J) the phenomenological yield coefficient 7 it equals the true yield coefficient if the lysis and maintenance rates fall. If for different dilution rates D the steady-state values x and s are measured with known Sq and k, one can determine true yield coefficient Yx s as well as the maintenance coefficient ms by linear regression on the basis of Equ. 6.22. 

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