Monday, May 5, 2008
9-14

Continuous flash fermentation applied for the production of biobutanol

Adriano Pinto Mariano, Department of Chemical Process, State University of Campinas (UNICAMP) - School of Chemical Engineering, CP 6066, ZIP CODE 13083-970, Campinas-SP, Brazil, Dejanira de A. Franceschi, Departamento de Bioquímica e Microbiologia, Universidade Estadual Paulista (Unesp), Av. 24-A, 1515 CP 199 CEP 13506-900, Rio Claro, Brazil, and Rubens Maciel Filho, Department of Chemical Process – School of Chemical Engineering, State University of Campinas, Cidade Universitária, P.O. Box 6066, Campinas, Brazil.

The objective of this work is to demonstrate the technical feasibility of the continuous flash fermentation for the production of butanol using mathematical modelling and computer simulation. The process consists of three interconnected units, as follows: fermentor, the cell retention system (tangential microfiltration) and vacuum flash vessel (responsible for the continuous recovery of butanol from the broth). The concentration of butanol in the fermentor lowered from 11.3 to 7.8 g.L-1, what represents a significant reduction of the inhibitory effect. As a result, the final concentration of butanol was 28.2 g.L-1, for a broth with 140 g.L-1 of glucose. Butanol productivity and yield were, respectively, 7.0 g.L-1.h-1 and 20.2 % and sugar conversion, 95.6 %. Compared to the conventional continuous fermentation process, the gains of the flash fermentation in terms of productivity, yield and conversion were approximately 150 %.