Effect of Substrate Concentration (Glucose) on Ethanol Fermentation Continue with Immobilized Fixed Bed Fermenter for 2/3 Mesh Pumice Anchoring Size

Abstract

The need for ethanol which is increasing at all times demands development related to ethanol production, especially those produced through the fermentation process both development in terms of raw materials and processes. Ethanol fermentation process continues to have problems one of them is wash out or the carrying of microorganisms into the product stream which causes the number of microorganisms to continue to decrease in the fermenter. One way to solve the problem of wash out is to tether the microorganism first to the anchoring medium (immobilized cell) and choose the suitable type of fermenter. The purpose of this study was to determine the effect of glucose concentration and the best conditions on the ethanol fermentation process continue with immobilized cell fixed bed fermenter to the value of ethanol concentration and yield ethanol produced as well as the percent of microorganisms still carried into the product streams. Based on the results of the study, the best conditions were obtained with a residence time of 2 days with the ethanol concentration of 1.20%v/v, the yield of fermented ethanol was 37.75%w/w, and % number of cells released was 0.45% at a glucose feed concentration of 150g/L. Fermentation is carried out under conditions of immobilized cell using microorganisms from the type of yeast Saccharomyces cerevisiae. In this study the variables that were considered fixed were the expansion ½ height of 1.47m column height, temperature of 25-30°C, and a pH of 5.5.