Continuous Ethanol Production from Molasses via Immobilized Saccharomyces cerevisiae on Different Carriers on Pilot Scale

Abstract

Immobilization of yeast cells for continuous ethanol production has been extensively studied all over the world during the few past years because it showed great advantages compared to the production by free cell system. And also, using of renewable substrate such as Egyptian cane and beet molasses become necessary to reduce using of food crops for bioethanol production. This study investigate the immobilization of commercial strain of Saccharomyces cerevisiae on different carriers (sugarcane bagasse, rice straw, wheat straw and Na-alginate) for continuous ethanol production on pilot scale. The results demonstrated that sugarcane bagasse was the best carrier for yeast cells immobilization and produced 66.30 g/l ethanol using a mixture of Egyptian cane and beet molasses with 16% initial sugar at 30 °C and pH 4.5., 2.76 g/l/h as ethanol productivity and 81% fermentation efficiency from theoretical value. From this study it was clear that lignocellulosic materials provide to be suitable, cheap and renewable carriers for immobilization of yeast cells which used in continuous ethanol production process.