FLUIDIZED-BED STEAM GASIFICATION OF RICE HULL

Steam gasification of grain by-products can be a significant biomass conversion technology because of the need to utilize agricultural waste for nonfood applications including energy resources. The most obvious beneficiary will be the developing countries whose economies are often tied to agricultural produce and are lacking in conventional fuels. One agricultural by-product that shows promise is the rice hull; it is found in abundance in the rice mills of producer countries and is considered as a waste material. Although gasification of rice hull has been proposed as a potential waste disposal and energy recovery method, little has been done to fully realize this proposition. In the present work, data were obtained for steam gasification of rice hull in a bench-scale fluidized-bed gasifier, a technology which has proven to be feasible for other grain by-products. The produced gas, which is rich in hydrogen, has been found to have a heating value ranging between 12.1 and 11.1 MJ m-3 at the respective reactor temperatures of 700 and 800-degrees-C; energy recovery varies between 35 and 59%.