Bioethanol Fermentation of Nipa Sap with Baker’s Yeast

Abstract

Bioethanol production from nipa sap with baker’s yeast was studied in this work. Nipa sap is a source of sugars, minerals and nutrients which is suitable as a raw material for the ethanol fermentation without nutrient supplementation. The sap was firstly pretreated with pH 4.9 at 54°C for 25 min before fermentation. Response Surface Methodology (RSM) was employed to design experimental conditions of the fermentation and to optimize the conditions. The important variables investigated were initial total sugar concentration (10 – 30 wt%), initial pH (4.5 – 6.5), yeast amount (0.01 - 1 g), temperature (28 – 40°C) and time (10 – 144 hours). An optimal condition achieved 82.4 g/L ethanol concentration with 99.5 ethanol yield was using 21.5 wt% initial total sugar with pH 6.2 and 0.9 g yeast at 35.6°C for 77 hours