Kinetics studies of fungal biogas production from certain agricultural waste

Abstract

Anaerobic degradation of sugar cane and rice husk by cellulolytic fungus was studied respectively at optimum operational condition of concentration, 1:5 w/v of the lignocelluloses: water and temperature of 33oC. The average rates of biogas production determined for sugar cane and rice
husk were 57cm3per day and 47cm3 per day, while the yield of biogas evaluated appear to be high, 15.2% for sugar cane and 12.5% for rice husk. The yields from other agricultural wastes were lower than these values (0.8% cow dung – 11.6% water hyacinth). The compositional yields of the biogas were also assessed; 5.7% CH4, 8.3% CO2, and 1.2% H2 S for sugar cane and 4.9% CH4, 6.1% CO2 and 1.5% H2 S for rice husk. Results have shown that the biogas of rice husk is of better quality than that of sugar cane because of its lower content of CO2. It was also found that when the amount of the substrates were respectively doubled, the average rate of the biogas production doubled, implying that kinetically, the degradation is probably first order. The yield of the bioliquid for sugar cane was determined as 94% and rice husk was 68%.

Key word: Biogas, Fungal Degradation, Bioliquid, Rice Husk, Sugarcane.