Production of Bioethanol from Dwarf Late Napier Grass (Pennisetum purpureum) Stems by Simultaneous Saccharification and Fermentation (SSF) Method Using Clostridium acetobutylicum Bacteria

The cellulose of dwarf-late Napier grass belongs to the carbohydrate group that has not been utilized optimally. The cellulose can be utilized with the help of microbes to produce bioethanol. This study aims to produce bioethanol from the stems of dwarf-late Napier grass (Pennisetum purpureum) through the process of saccharification and simultaneous fermentation (SSF) using Clostridium acetobutylicum bacteria. The SSF method combines enzymatic hydrolysis and fermentation processes. As variables of this study, in the first stage, dwarf-late Napier grass stems were pre-treatment with the addition of 3% NaOH and bleaching with 3% H2O2 to remove lignin from the cellulose. In the second stage, the dwarf-late Napier grass stem cellulose was fermented by the SSF method. The results showed that the dwarf-late Napier grass stem cellulose after pre-treatment was 75.37%. The optimum condition of fermentation was obtained at pH 6.5 for ten days of fermentation with the use of dwarf-late Napier grass stems as much as 68 g after pre-treatment was able to produce 13.5 mL of bioethanol with a concentration of 86.25%. The results