Fluidization of high-density particles : the influence of fines on reactor performance

Abstract

The effect of fines on the hydrodynamics of a gas–solid fluidized bed and ozone decomposition reaction was investigated using high-density iron-silicon (FeSi) particles with a particle density of 6690 kg/m3. The addition of fines decreased the bubble size, dense phase voidage and reactor performance. The bubble size decrease is in accordance with reported literature; while, increase in dense phase voidage and reactor performance was found in the literature on less dense catalyst. The reactor performance was quantified using an apparent overall mass transfer parameter derived from fitting a two-phase model to the experimental data. The method allowed for reactor performance comparison despite the fluctuation in FeSi particle activity. Model fitting results suggest that smaller bubbles should improve mass transfer in addition to reactor performance. However, the decreased dense phase voidage with addition of fines counteracted the effects of smaller bubbles. Higher entrainment rate of the bed with fines was noted.