The utilization of sawdust for ethanol production

Abstract

Currently, Indonesia is in the middle of petroleum crisis. One of the alternative fuels which can be used as a petroleum substitute is ethanol. Ethanol can be produced from the timber waste (sawdust). Indonesia, in 2003, had timber waste potency of about 3 – 4 millions m3. Process of sawdust manufacturing become an ethanol can be conducted by simultaneous saccharificationfermentation method. However, ethanol production from sawdust has problem due to its lignin content. Therefore, research on bio-delignification treatment of sawdust prior to ethanol making process is required. The research was done by acted of growing white rot fungi Phanerochaete chrysosporium on three kinds of sawdust i.e. jati, meranti and sengon. The chemical contents (extractive contents, cellulose contents, holocellulose contents, ash contents and lignin contents) of these three of sawdust were analyzed previously. Then simultaneous saccharification-fermentation (SSF) process was done by using crude enzyme from Trichoderma viride and then followed by fermentation with Saccharomyces cerevisiae on shaker incubator with rate 12 rpm at temperature 30oC for 72 hours. The result as an ethanol was analyzed by using gas chromatography method. Analysis design used was completely randomized design using 2 factors of treatment i.e. type of wood (A) and time of incubation (B). Pretreatment with Phanerochaete chrysosporium on various types of sawdust and incubation time rises up ethanol contents up to about 26.68 – 76.90%. Chemical contents of sawdust having significant effect to ethanol contents was holocellulose, the higher holocellulose contents give higher ethanol contents. Ethanol contents resulted was about o.o16 – 0.448 g/l. Interaction between factor type of wood and time of incubation had significant effect to ethanol content. The best combination treatment was on sengon sawdust with incubation period of 30 days.