DEVELOPMENT OF BIOETHANOL PRODUCTION PROCESS FROM SORGHUM

• Main Author: Maritza Falenia Isyana, RR.
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71817
• Institution: Institut Teknologi Bandung

At the moment, Indonesia is trying to increase the use of renewable energy sources to reduce imports of fuel. Currently, Indonesia has not been able to realize 5% (E5) bioethanol in fuel, because in 2022 the total production of new fuel-grade bioethanol just reached 40,000 KL per year, or far below the requirement of 696,000 kL per year to be able to be implemented for the initial stages in the East Java and Jakarta regions. Currently, molasses from a sugar cane factory is the main raw material for the bioethanol industry. Indonesia is a country with abundant natural resources. However, there is one raw material that has not been explored much, namely sorghum. Sorghum is valued as a raw material for bioethanol for fuel substitution. In this study, bioethanol production is produced by fermenting sorghum sugar using Saccharomyces cerevisiae. In the fermentation process, the High Cell Density Cultivation (HCDC) method is used, which is a technique to produce microbial cells at high concentrations to produce high product concentrations. Ammonium nitrate is also added as additional nitrogen, which is an important nutrient in fermentation for the growth of S. cerevisiae and bioethanol production. There are three factors varied in this study, the first is in terms of °Brix of sorghum sugar at 15 °Brix, 20 °Brix and 25 °Brix. The second variation is the initial concentration of cells in cells/mL of 1x10?, 1x108, and 1x109. The last variation is the amount of ammonium nitrate at 1%, 2%, and 3%. Of the three factors, the optimum ethanol yield was obtained at 25 °Brix with the ethanol yield reaching 44,408 g/L, while the highest ethanol yield was also obtained with increasing initial cell concentration.