Principal Properties and Design of CPFRs Compared with CSTRs

3 Principal Properties and Design of CPFRs Compared WITH CSTRs 

The CPFR has distinct advantages for those bioprocesses that call for a specific reaction time, as illustrated in Fig. 6.27. Examples of such processes include the formation of the products of secondary metabolism, sterilizations to destroy cells and spores, and the high temperature treatment of foodstuffs. 

However, practical engineering experience with a tubular reactor, for example, for biological waste water treatment (F. Moser, 1977, 1980) shows that 

Equations 6.77 and 6.78 are generally applicable (for example, to sterilizations) and can be formulated for use in the case of enzyme kinetics involving 

However, even at low Xg values, the CPFR continues to have a clear volume advantage (as may be seen in Fig. 6.30) when the attainment of either a high conversion or a low S concentration in the effluent (Sgx 20 mg/1) is an important consideration (e.g., biological waste water treatment, (A. Moser, 1977 Wolfbauer, Klettner, and Moser, 1978). This consideration of low Sgx is not of such great significance in fermentation processes (except perhaps with expensive substrates), so the advantage of a CPFR is not nearly so pronounced (Finn and Fiechter, 1979). 

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