Effect of Oxygen Concentrationon Thermal Decomposition of Polystyrene in Fluidized Bed

Abstract

Thermal decomposition of polystyrene was studied in a batch fluidized bed of 35 mm ID under atmospheric pressure, at temperatures ranging from 380 to 550°C, with gas rate from 0.5 to 4.0 cm/sec, the gas containing oxygen up to 21.0 vol %.
The overall reaction rate was found to obey the first-order equation. The distilling rate of liquid product proceeded comparatively to the rate of loss-weight. The result obtained was
Rw=dw/dθ= (k₀^*+k_α^*·y^0.8)w
where Rw : reaction rate by loss of weight method dw/dy
w : fractional weight
k₀^*, k_a^* : coefficients of rate equation in the inert gas and the gas contained oxygen, respectively
y : oxygen concentration
θ : reaction time after the induction period
When the y is about 18% and the temperature from 400 to 500°C the liquid product yield was maximum over 70 wt %.