ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Efficiency of a fixed-bed and a gas-lift three-column reactor for continuous production of ethanol by pectate-and alginate-immobilized Saccharomyces cerevisiae cells

M. Valach, M. Navrátil, V. Horváthová, J. Zigová, E. Šturdík, E. Hrabárová, and P. Gemeiner

Department of Biochemical Technology, Faculty of Chemical and Food Technology, Slovak University of Technology, SK-812 37 Bratislava, Slovakia

E-mail: milan_valach@stuba.sk

Received: 28 July 2005  Revised: 8 November 2005  Accepted: 16 November 2005

Abstract: Ethanol-tolerant and thermo-tolerant yeast strain Saccharomyces cerevisiae C11-3 cells immobilized in calcium pectate and calcium alginate gels were used for ethanol fermentation in a three-reactor system with a gradient temperature control. The fermentation process has been tested in a fixed-bed and a gas-lift arrangement. The gas-lift system was more efficient due to a better mass transport between the phases. Abrasion was more evident in calcium alginate particles, while calcium pectate beads were not significantly damaged. Two different concentrations of alginate were tested and calcium pectate gel was demonstrated to be more suitable as an immobilization material in comparison with calcium alginate due to its mechanical resistance and favourable diffusion parameters, providing an ethanol production of more than 7.5 g dm⁻³ h⁻¹ over a period of 630 h.

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-006-0028-6

Chemical Papers 60 (2) 154–159 (2006)