Pyrolysis of scrap printed circuit board plastic particles in a fluidized bed

Pyrolysis behavior and corresponding pyrolysis products of printed circuit board plastic particles (PCBP particles) were investigated in a fluidized bed using TG-FTIR analysis system. PCBP particles were separated from crashed printed circuit boards using fluidized beds, 354 μm crashed plastic particles were pyrolyzed at the temperature ranging from 20 to 900 °C by a thermogravimetric analyzer. Two stages of decomposition were identified for PCBP particles under nitrogen conditions. The activation energy was 90.49 kJ/mol for the first-stage reaction and 137.80 kJ/mol for the second-stage reaction. Further, gas products, liquid products, and solid residues yielded in the fluidized bed were analyzed using an elemental analyzer and FTIR. It has been found that the liquid yields increased with an increase in pyrolysis temperature, and with an increase in superficial gas velocity. The main compositions of liquid products were aromatic compounds including substituted benzenes. Whereas, the solid products mainly contained char and fiberglass.

A fluidized bed, made of a stainless steel cylinder with 27 mm i.d. and a height of 1600 mm, was used to pyrolyse the printed circuit board plastic (PCBP) particles at bed temperature ranging from 400 to 600 °C. The gas and liquid products and solid residues yielded in the fluidized bed were analyzed.Figure optionsDownload as PowerPoint slide