PENENTUAN KONDISI OPTIMUM (JUMLAH YEAST) FERMENTASI UBI JALAR PUTIH (IPOMEA BATATAS LINNEAUS) UNTUK PENINGKATAN HASIL BIOETANOL

The Optimum Conditions of Fermentations Ubi Jalar Putih (Ipomea Batatas Lenneaus) to Increase The Bioethanol Product by Yeast Contents (Hadi Gimantoro 2014, 75 pages, 16 tabels, 27 pictures) The aim of this research is to know the conditions optimum of fermentation Ubi Jalar Putih (Ipomea Batatas Lenneaus) by using yeast to increase the bioethanol product. The fermentation process at room temperature and atmospheric pressure bellow the variations of yeast from 7,2%, 7,6%, 8,0%, 8,4%, 8,8% and 9,2% by using 100 grams Ubi Jalar Putih. The research from Nur Rohmadi with the title is Pembuatan Bioetanol Dari Ubi Jalar Putih has result the highest bioethanol is 8 mL by using yeast 8 grams from 100 grams ubi jalar putih. The fermentation products in these researches with variation of yeast, using pati ubi with aquadest 1 devided 10, and using with pati content 1 devided 18 by the optimum condition of fermentations in six days with total yeast 8,4% w/w from 100 grams ubi jalar putih. The product of bioethanol is 9 mL with 64,59 purity. The characteristic of bioethanol were indeks bias 1,341 with colourless bioethanol and density is 0,792 gr/mL, boiling point is 78,3oC and the flame colour is blue. Keyword: Bioethanol, Ubi Jalar Putih and Anaerob Fermentatio