Naslov
Development of hybrid integrated bioprocess for ethanol production

Autori
Mario Novak, Predrag Horvat, Božidar Šantek

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
2nd Annual European Postgraduate Sustainable Development Symposium - Book of Abstracts , 2012. / Narodoslawsky, Michael ; Schnitzer, Hans - Graz : Verlag der Technoschen Universität Graz, 2012, 25-25

ISBN
978-3-85125-207-1

Skup
2nd Annual European Postgraduate Sustainable Development Symposium

Mjesto i datum
Graz, Austrija, 15.02.2012. - 17.02.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
hibridni bioprocesi; bioetanol; matematičko modeliranje
(hybrid bioprocesses; bioethanol production; mathematical modeling)

Sažetak
Integrated bioprocess [1] for ethanol production usually combines simultaneous extraction of sucrose from raw sugar beet cossettes, fermentation with a high sugar concentration tolerant strain of yeast Saccharomyces cerevisiae and ethanol recovery from fermented broth. In this research, sucrose extraction from raw sugar beet cossettes in extraction column was studied by different experimental conditions (water temperature and residence time). On the basis of obtained results, mathematical model was established that describes sucrose diffusion from sugar beet cossettes and stagnant medium layer around sugar beet cossettes coupled with convective medium flow in the extraction column. Yeast growth at high substrate concentrations was also studied in order to define kinetic parameters of yeast growth by using differential method. Obtained results clearly pointed out that Jerusalimsky [2] model shows the best agreement with experimental data. Integrated bioprocess system that combines horizontal column bioreactor and stirred tank bioreactor was used for the study of simultaneous sucrose extraction from sugar beet cossettes and ethanol production by using different initial yeast concentration, residence time and bioprocess temperature. On the basis of experimental data two mathematical bioprocess models were established. First model is "cascade" model [3] that describes the whole bioreactor system as series of ideally mixed compartments with back mixing. For each ideally mixed compartment mass balance was established that describes hydrodynamic, mass transfer and reaction phenomena. For whole system set of differential equations was obtained and solved by numerical methods. Second bioprocess model was developed by Computational Fluid Dynamics (CFD) approach. In this approach, the mass balance was established on the micro-scale level and consequently the set of differential equations was also obtained that describes the same phenomena as by first model. Comparison between these two models was done on the basis of model discrepancies from experimental data and it was observed that second model has better agreement with experimental data. Integration of different bioprocess operations into one step can considerably reduced ethanol production costs and consequently lower impact on the environment (lower sustainable process index (SPI [4])). Established integral bioprocess models could be also used as a good tool for the bioprocess optimization and the evaluation of bioprocess sustainability.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

POVEZANOST RADA