Generation of Electric Energy from Gasifying Rice Husk and Utilization of Its By-Products to Cementitious Materials

In recent years, a system has been developed to generate electricity energy by rice husk gasification and reuse the energy as a power source for agricultural facilities, but the use of “rice husk ash” discharged by gasification is limited. The authors have been developing structural materials using “rice husk ash”. The reason for focusing on rice husks and rice husk ash is that they can contribute to resource reuse, energy generation, and improvement of mechanical properties by pozzolanic reaction. In term of the reduction of environmental burdens, this paper analyzes both the carbon dioxide emissions of producing rice husk using a rice husk biomass power plant operated by a cogeneration system as a case study, and the effectiveness in the reduction of carbon dioxide generated in the production of the material by adding rice husk ash. As a result, the cogeneration system creates twice as large energy as the input and utilizing rice husks decrease the amount of carbon dioxide emissions by 47 tons in a year. Replacing the solidifier with rice husk ash reduces carbon dioxide emissions in production of the material. In particular, cement materials have the lowest carbon dioxide emissions. Compared to MgO materials, carbon dioxide emissions in cement material are about 1/3. Therefore, the utilization of rice husk and rice husk ash for structural material lighten the environmental burden.