High-Temperature Pyrolysis of Polyethylene in a Fluidized Bed

Abstract

Pyrolysis of high-density polyethylene (HDPE) pellets as a model of plastic wastes was studied at a furnace temperature of 700°C to 800°C and under nitrogen atmosphere in a silica sands fluidized bed of 5.5cm inner diameter. The operating conditions such as the reaction bed temperature, feed rate of HDPE, and superficial velocity of fluidizing gas were varied.
The pyrolysis reaction was essentially complete in this range of reaction temperature. The gas produced became of lower molecular weight at higher reaction temperatures and at longer residence time. As the feed rate of HDPE increased, the product gas per unit weight of HDPE became small in volume, but of higher calorific value.