Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-V-21ESTIMATION OF OPTIMAL REACTOR VOLUMES FORBIOCATALYST PRODUCTION USING NLP FORMULATIONMarko Tramšek, Andreja GoršekUniversity of Maribor, Faculty of Chemistry and Chemical Engineering, Smetanova 17,SI–2000 Maribor, Slovenia, fax: ++386 2 252 77 74,e-mail: marko.tramsek@uni-mb.si, andreja.gorsek@uni-mb.siAbstractMany novel applications of kefir grains as biocatalyst or raw biomaterial in recent years(Plessas et al., 2005; Rimada and Abraham, 2001; Athanasiadis et al., 2001; Athanasiadis etal., 2004) require incorporating of economically efficient reactor systems into kefir grainsproduction processes. Traditionally, production operates in batch mode. However, there areseveral well-known advantages for using continuous operation instead of batch one(Williams, 2002). Despite the promising idea of incorporating the continuous mode operationin classic kefir grains production, no research papers concerning this kind of design have beenpublished so far.Therefore, the main goal of the present study was to design a continuous multi-stagereactor system for kefir grains production. In order to minimize total volume of CSTRs, V T , inmulti-stage reactor system, for desired kefir grains capacity, q m,KG,pr , and final conversion inNth CSTR, X o,N , with regard to decreasing of fermentation medium pH, a NLP optimizationproblem has been formulated:min VTNj = 1( )( )( o, o,( −1))( o,( N−1))V = f X ; X = constant; N = 11 o,1 o,1V = f X ; N > 11 o,1j j jjV = f X ; N ≥ 2N=∑ VV = f X , X ; N > 2; 1 < j