Bioethanol from Guinea Grass Panicum maximum and Ragi Tempeh as Fermentation Starter Using Bioreactor and Shaker

This study was for investigating the production of bioethanol from the mixture of guinea grass Panicum maximum and using Ragi tempeh through fermentation. The acid pretreatment process was carried out using 15% v/v sulphuric acid. The fermentation was carried out in anaerobic condition using bioreactor and shaker at 37 degrees C and different pH of 5, 6, 7, and 8. Freezing test and Tollens' test result showed variation of ethanol concentration in the sample product is very low, and aldehyde compounds are present in the product sample. The aldehyde is released due to degradation of lignocellulosic feedstock by acid hydrolysis. HPLC is carried out for getting a more accurate result. The best result is chromatogram of sample 5, obtained by fermentation using shaker with pH 8. It shows normal chromatogram with ethanol yield of 7.89%.