Production of Bioethanol from Seaweed, Gracilaria verrucosa and Eucheuma cottonii, by Simultaneous Saccharification and Fermentation Methods

Abstract

Demand for bioethanol in Indonesia will increase with the increase of energy need. Seaweeds, Gracilaria verrucosa and Eucheuma cottonii containing high cellulose content are considered very suitable to be developed in Indonesia and can be used as a raw material for low cost bioethanol production. The seaweeds were obtained from Mandalle, Pangkep Regency, South Sulawesi, Indonesia. The method used in this research was a simultaneous saccharification and fermentation (SSF) process. The results showed that 1. G. verrucosa and E. cottonii seaweeds could be converted into bioethanol having ethanol levels of 5.7% and 6.1%, respectively after 10 days of fermentation. 2. The optimum condition of fermentation process of G. verrucosa and E. cottonii using Clostridium acetobutylicum bacterium to produce ethanol was 10 days fermentation at pH 6.0 with the ethanol level of 7.7% and 7.2%, respectively. 3. The conversion value when G. verucosa cellulose was used as the raw material was 3.33% (33.3 g of bioethanol was produced from every kg of cellulose) with the obtained ethanol having the purity of 96.4%.