Effects of temperature distribution on the catalytic pyrolysis of polystyrene waste in a swirling fluidized-bed reactor

A swirling fluidized-bed reactor (0.0508 m ID and 1.5 m in height) has been developed to recover the styrene monomer and valuable chemicals effectively from the polystyrene waste, since it can control the residence time of the feed materials and enhance the uniformity of the temperature distribution. To increase the selectivity and yield of styrene monomer in the product, catalyst such as Fe2O3. BaO or HZSM-5 (Si/Al = 30) have been used. Effects of temperature, volume flow rate of gas, pyrolysis time and the ratio of swirling gas to the amount of primary fluidizing gas on the yields of oil product as well as styrene monomer have been determined. Effects of operating variables on the temperature distributions and their fluctuations in the radial as well as axial directions have been also examined to analyze the effects of temperature distributions and their fluctuations on the catalytic pyrolysis of polystyrene waste in the swirling fluidized-bed reactor. It has been found that the reaction time and temperature can be reduced profoundly by adding the solid catalyst. The swirling fluidization mode makes the temperature fluctuations more periodic and persistent, which can increase the uniformity of temperature distribution by reducing the temperature gradient in the reactor. The yields of styrene monomer as well as oil products have increased with increasing the ratio of swirling gas (V-2/V-1), but exhibited their maximum values with increasing the total volume flow rate of gas. (C) 2003 Elsevier Science B.V. All rights reserved.