The role of some process variables in the operation of fluidized bed pyrolysers of plastic wastes

In the family of feedstock recycling processes (the advanced recycling technologies for material recovery from plastic wastes) the fluidized bed pyrolysis is probably the most promising, for the high value of its products, the flexibility of the process and the possibility to apply it on a relatively small scale. This study describes how some process variables (bed temperature, polymer feed rate, bed hold-up, fluidizing velocity, size of inert material) affect the performance of a fluidized bed pyrolyser charged with different kind of plastic wastes. The results highlight how a deep knowledge of the hydrodynamics of the fluidized bed and of the interactions between bed and polymer particles is indispensable to define design and operating criteria for the reactor, to develop reliable modeling of its performance and to avoid economic waste.