Studi Pemanfaatan Limbah Makanan Sebagai Bahan Penghasil Etanol untuk Biofuel Melalui Proses Hidrolisis pada Kecepatan Pengadukan dan Waktu Fermentasi yang Berbeda

Abstract

ABSTRACT Most of food waste consisting mainly with carbohydrates that can be fermented to produce ethanol. The carbohydrate polymers are hydrolyzed using HCl acid to be split into glucose. Hydrolysis process carried out with the aid of stirring so that the collision occured between the carbs and HCl acid. In this study, an agitating between them are varieted with stirring speed of 100 rpm, 150 rpm and 200 rpm, so that it can be seen the effect of agitating into result of glucose . The result of hydrolysis show that concentration of glucose increase to point 17,13% (v/v) on agitating speed of 150 rpm. Then the hydrolyzate liquids are fermented using yeast (Saccharomyces cerevisiae). Fermentation process was conducted at 18 days varied, then doing ethanol test every three days. The result shows ethanol concentrated are highest at 18 days fermentation, there are ranging between 44,01% (v/v) with agitating speed of 100 rpm; 44,59% (v/v) with agitating speed of 150 rpm; 45,11% (v/v) with agitating speed of 200 rpm.The highest ethanol content increased on 9 days fermentation, meaning that on that day content of ethanol increase higher than the previous day. Slowing increased levels of ethanol started to happen on day 18, it relates to the ability of yeast to use ethanol as an energy source or age of yeast has been used for too long. Key words: food waste, acid-based hydrolysis, agitation, fermentation of glucose, ethanol.