POTENSI LIMBAH PADI, SORGHUM, DAN JAGUNG SEBAGAI BAHAN DASAR PRODUKSI ETANOL

The availability issue and environmental problems as the resultof the use of fuel become the concern of the world community, including Indonesia. Ethanol has attracted attention as an alternative energy since the oil crisis. Ethanol can be produced from the fermentation process a wide variety of materials such as agricultural waste material containing lignocelluloses, or materials that contain saccharin. Popular types of agricultural crops cultivated in Indonesia arecereal crops such as rice, corn, glutinous rice, and sorghum. Parts of plants such as corn stalks, wheat straw, rice straw, rice husk, and baggase are residue andbyproducts which can be used as raw material for production of bioethanol. The agricultural wastes contain cellulose which can be hydrolyzed into sugars and then be used as a substrate in the fermentation process. Hydrolysis can be done by using various methods such as physical method through evaporation, chemical method by using acid and or enzymatic method. Saccharomyces cerevisiae, which is able to produce ethanol in large quantities and havea high tolerance for alcohol, as well as its easy application to industrial scale, is commonly used in industrial fermentation of glucose into ethanol. This research used the waste of rice straw, rice husk, straw ofglutinous rice, sticky rice husk, brown rice straw, red rice husk, sorghum leaf, sorghum stem, remainder of sorghum grain, corn leaves and corn husk as raw material. The cereal waste enzymatically hydrolyzed using cellulose enzymes to convert the cellulose into simpler sugar. The result of the enzymatic hydrolysis was used as a substrate in the ethanol fermentation process using the S.cerevisiae. Analysis of sugar level reduction and ethanol produced was used to measure the efficiency of fermentation. The cellulose enzyme with 100 FPU/g enzyme activity of dry material was used in the research. The highest glucose level as the result of the sorghum stem hydrolysis was 5, 04 mg/ml with the conversion value of cellulose into glucose 93.493%. The highest result of ethanol fermentation product wasproduced by the hydrolysates of sorghum stem with 0,236% (v/v) ethanol level and 0,118 yield ethanol almost similar to the results of theoretical ethanol yield calculations worth 0,123