Recently, with increasing of fuel consumption and due to the limitation of fossil fuels and their environmental problems, demand for renewable clean fuels such as biogas and ethanol is increased. Due to the availability and abundance of lignocellulosic materials and their low price, use of these materials can solve the problems of biogas and ethanol production. Furthermore, using the renewable fuels contribute to reducing environmental pollutions. In this study, pinewood as a lignocellulosic material was used for the production of ethanol and biogas. To improve the biofuel efficiency, alkali and acid pretreatment using sodium hydroxide and sulfuric acid were evaluated. After the pretreatment, solid part was used for ethanol production via a separate hydrolysis and fermentation. Moreover the sugar solution obtained from the pretreatment was subjected to biogas production via a anaerobic digestion. The pretreatments were performed with 0, 1, and 2% w/v NaOH solution as well as 0, 0.25, and 0.5% w/w H 2 SO 4 solution at 100, 140, and 180 °C. Alkali pretreatment was conducted for 1, 2, and 5 h while acid pretreatment was performed for 5, 10, and 30 min. The pretreatments were carried out in a high pressure reactor. The sugar solution obtained from the pretreatment was detoxified and neutralized, and then used in anaerobic digestion for biogas production. The pretreated and untreated pine were hydrolysed to glucose using cellulase and ?-glucosidase at 45°C for 72 h. The best pretreated samples in terms of biogas production and sugar production in hydrolysis was used for ethanol production by separate hydrolysis and fermentation using Saccharomyces cerevisiae at 32°C. The highest suger production yield was obtained by pretreatment with 2% NaOH at 180°C resulted in a yield of 78%, while for untreated pine, it was only 7.9%. The best results from the fermentation was 17.g/L with ethanol yield of 86.5%. The best yield of methane production was achieved by the treatment with 0.5% H 2 SO 4 at 140°C for 5 min, resulted in a methane yield of 275 ml /gr.VS. The compositional analysis showed complete removal of hemicellulose has occurred by the pretreatment, while lignin was not significantly separated from the samples. Keywords Biogas, ethanol, pinewood, alkali pretreatment, acid pretreatment.
