Fluidized bed combustion of rice husk to produce amorphous siliceous ash

This paper presents research work on producing amorphous siliceous ash with low carbon content through combustion of rice husk in a fluidized bed combustor. Preparation of high-purity amorphous siliceous ash through the conventional alkaline extraction method is time-consuming and costly. Various drawbacks are associated with the preparation of siliceous rice husk ash via thermal treatment of rice husk in existing thermal treatment technologies, the main being the formation of crystals, high residual carbon in ash and long reaction time. Fluidized bed technology is capable of producing amorphous rice husk ash with very low carbon content in a very rapid reaction time due to its high combustion intensity and good mixing behaviour. The achievements and potential areas for development of the current research are also presented. Lastly, the quality of ash has been given particular attention in terms of amorphous nature and carbon content.