RENEWABLE ENERGY AND AMORPHOUS SILICA OBTAINED FROM RICE HUSK COMBUSTION IN A FLUIDIZED BED REACTOR

摘要

The rice husk combustion in a bubbling and atmospheric fluidized bed reactor was investigated.The results showed the technical viability of producing both heat and amorphous silica from arenewable energy source. This paper presents the characterization of rice husk ash (RHA)obtained under varying fluidization velocities (0.13-0.15 m/s) and rice husk feed (4.5-7.2 kg/h).Characterization techniques include X-ray fluorescence, X-ray diffraction, particle sizedistribution and scanning electron microscopy. For the employed range of fluidization velocitiesof rice husk feed no noticeable influence on the chemical composition of produced RHA wasobserved. After combustion, RHA containing ～93% amorphous silica and <3% unburned charwas obtained. RHA primary particles presented sizes from 90 to 100 μm and a tendency foragglomeration in aqueous media. Thus, the potential of this type of reactors with respect tospeed, continuity and self-sufficiency energy of the process was shown.