Production of Ethanol from Beet Molasses by Ca-Alginate Immobilized Yeast Cells in a Packed-Bed Bioreactor

Authors : Yekta GÖKSUNGUR, Neşe ZORLU

Pages : 265-275

View : 11 | Download : 6

Publication Date : 2001-12-01

Article Type : Research Paper

Abstract :The continuous production of ethanol from beet molasses by Ca-alginate immobilized Saccharomyces cerevisiae in a packed-bed bioreactor was investigated. The temperature was maintained at 30°C and the dilution rate was 0.22 h-1. Maximum ethanol insert ignore into journalissuearticles values(4.62%);, theoretical yield insert ignore into journalissuearticles values(82.9%); and volumetric productivity insert ignore into journalissuearticles values(10.16 gl-1h-1); were obtained from the beet molasses medium containing 10.90% total sugar with 2.0-2.4 mm diameter beads prepared from 2% insert ignore into journalissuearticles values(w/v); sodium alginate solution. At higher substrate concentrations, substrate was recirculated through the packed-bed bioreactor to increase yields and to decrease residual sugar content. The bioreactor system was operated at a constant dilution rate of 0.22 h-1 for 25 days without loss of original fermentation capacity. Compared to packed-bed bioreactor, lower ethanol concentration insert ignore into journalissuearticles values(3.94%);, theoretical yield insert ignore into journalissuearticles values(70.7%); and productivity insert ignore into journalissuearticles values(8.67 gl-1h-1 ); were obtained in the continuous stirred bioreactor.
Keywords : ethanol, beet molasses, calcium alginate, immobilization, packed bed bioreactor