Selasa, 29 November 2011

BIOETHANOL PRODUCTION FROM SEVERAL TROPICAL WOOD SPECIES USING SIMULTANEOUS SACCHARIFICATION AND FERMENTATION PROCESSES


BIOETHANOL PRODUCTION FROM SEVERAL TROPICAL WOOD SPECIES USING SIMULTANEOUS SACCHARIFICATION AND FERMENTATION PROCESSES

Muhammad Daud1, Wasrin Syafii2, Khaswar Syamsu3

1Faculty of Forestry, Hasanuddin University
2Faculty of Forestry, IPB
3Agricultural Industry Technology Department, IPB

ABSTRACT


The study was conducted to determine the best method to hydrolyse (saccharification) and fermentation in bioethanol production using simultaneous saccharification and fermentation processes. Three  different tropical wood species namely gmelina wood (Gmelina sp.), pine wood (Pinus merkusii) and oil palm (Elaeis guineensis Jacq.)  were  pretreated using kraft process and then were produced to bioethanol using simultaneous saccharification and fermentation (SSF) processes. Pulp were produced from kraft process were analize to determine their chemical properties before treatments. SSF runs were performed in 500 ml fermentors using a  total slurry 200 ml. The substrate and nutrient media were autoclaved (121 oC and 20 minutes). The samples diluted to 2,5% (w/v) of total slurry was used as substrate. The enzyme preparation used commercial cellulase enzyme. The amount of cellulase added were 8% and 4% (w/w) dry mass of samples. All SSF processes were inoculated with 10% (v/v) yeast Saccharomyces cereviciae (1.5 x 109 CFU/cc). The SSF experiments were run for 96 hours, and the data were investigated periodically every 24 hours. The results showed total of sugar and reducing sugar tended to decrease with time of inoculation whereas ethanol concentration increase significantly. The growth of yeast Saccharomyces cereviciae tended to incease in initial inoculation and decrease by the end of inoculation. The best method to hydrolyse (saccharification) and fermentation on SSF processes for all tropical wood species were using cellulase 8% of dry mass (DM) and 10% (v/v) of Saccharomyces cereviciae which produced highest bioethanol concentration gmelina, pine and oil palm were 0.98%; 0.57% and 0.51% respectively and produced yields 11.21%, 5.85% and 3.20%, respectively.

Key words:  Bioethanol, simultaneous saccharification and fermentation, tropical wood  species, cellulase, Saccharomyces cereviciae