Energy generation from fluidized bed gasification of rice husk

Though gasification of biomass in fluidized bed system is an efficient way of biomass utilization, limited experimental data on the fluidized bed biomass gasification are available in open literature. Therefore, an experimental study of biomass gasification is conducted using a laboratory scale bubbling fluidized bed gasifier. Rice husk is used as the biomass material and air-steam mixture is used as the gasifying agent. As the non-granular nature of rice husk makes it difficult to fluidize, silica sand is used as the inert bed material to help in fluidization. Parametric studies are performed to determine the effects of reactor temperature, equivalence ratio, and steam-to-biomass ratio on the product gas composition and the heating value. The results show that both hydrogen percentage and the heating value of the product gas increase with increase in gasification temperature and steam-to-biomass ratio, but they decrease with increase in equivalence ratio. The maximum heating value (4.26 MJ/Nm3) and hydrogen percentage (13.1%) are obtained at the gasification temperature of 850 °C, equivalence ratio of 0.35 and the steam-to-biomass ratio of 0.8.