Revalorization of rice husk waste as a source of cellulose and silica

Cellulose and silica were obtained from rice husk by a multi-step procedure. Three different strategies including different alkaline and bleaching steps were evaluated by Fourier transform infrared spectroscopy (FTIR) in order to choose the sequence that combines the better conditions to obtain both subproducts simultaneously. The effects of the different steps on the structure and morphology of original material treated by the selected procedure were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results suggest that it is possible to obtain both by-products with a simple procedure, giving an added value to this waste.