Effect H₂SO₄and Zymomonas mobilis concentration to bioethanol production bybintarofruit (cerbera manghas) substrate

Abstract

Abstract. Bintaro fruit (Cerbera manghas) contains 36.945 of cellulose and 38% of lignin which is potential as a source of raw material for making bioethanol. The purpose of this research is to know the effectiveness of formula in producing bioethanol by the process of bintaro. The methods used in this research are pretreatment, delignification, hydrolysis, fermentation, and distillation. Pretreatment was performed by subcooling the substrate at 80 0 C followed by milling it up to 60 mesh. Delignification was performed by soaking the substrate in 100 0 C of 1N NaOH and 1 barr for 30 minutes. Hydrolysis was carried out with sulfuric acid catalyst (H2SO4) variations of 5.5%, 6.0%, and 6.5% at 120 0 C for 60 minutes. Fermentation with Zymomonas in variation of 1%, 3%, and 5% at room temperature for 3 days. The fermented filtrate was distilled at 73 0 C to obtain ethanol and tested the levels of ethanol with chromatography gas. The results showed that the highest levels of ethanol is 9.977% resulted from 6.5% of sulfuric acid hydrolysis and 5% of Zymomonas mobilis fermentation. The high levels of ethanol is supported by qualitative test result of the presence of reducing sugars with fehling yielding of 7002 ppm red brick tested quantitatively by nelson somogyi method. In conclusion, the level of bioethanol produced is directly proportional to the increased concentration of sulfuric acid and Zymomonas mobilis. The conclusion is levels of bioethanol produced is directly proportional to the increase in the concentration of sulfuric acid and Zymomonas mobilis is used.