KUALITAS BIOETANOL TUAK TUBAN NIRA SIWALAN (BORASSUS FLABELLIFER LINN) DENGAN METODE FERMENTASI SEBAGAI BAHAN BAKAR ALTERNATIF

Currently in Bojonegoro and Tuban Tuak siwalan is only used as a drink by young and old people. In fact, Tuak siwalan (Borassus Flabellifer Linn) contains 36.1 mg of carbohydrates which can be used as raw material for making ethanol. This study aims to determine the highest ethanol content of Tuak siwalan (Borassus Flabellifer Linn) with variations in the amount of yeast (Saccharomyces Cereviceae) and fermentation time. The results showed that the longer the fermentation time, the higher the ethanol content produced. By varying the fermentation time, the best fermentation time is 24 hours and by varying the amount of yeast, the best amount of yeast is 40 grams with an ethanol content of 45% after going through a multistage distillation process.