Biogas Production from Napier Grass (Pak Chong 1) (Pennisetum purpureum x Pennisetum americanum)

The objective of this research was to evaluate the quantity of biogas production from napier grass (Pak Chong 1) (Pennisetum purpureum x Pennisetum americanum) in three identical continuously stirred tank reactor (CSTRs) at room temperature. The volatile solids feed was varied at 1.5, 2 and 3%, respectively. The organic loading rate was altered at 0.43, 0.57 and 0.86 kg VS/m(3).d in CSTR 1, 2 and 3, respectively. Three laboratory scale CSTRs with working volume of 5 I were carried out. The results showed that the optimum volatile solids fraction was 2% VS with maximum biogas production of 0.529 m(3)/kg VS added. The methane production was achieved at 0.242 m(3)/kg VS added. Under this condition, the soluble chemical oxygen demand (SCUD) of the hydrolysate was increased by 74% and the SCUD and VS removal efficiency were obtained 52.52% and 55.98%, respectively. The highest total volatile fatty acid was obtained on day 12, which was 5.51 g/l and the highest concentration of HAc was 4.33 g/l. The results indicated that volatile solids fraction was 2% VS achieves a maximum biogas yield and can be successfully converted using anaerobic digestion and was investigated into economical and scalable.