Catalytic pyrolysis of metal free PCBs with ZSM-5 and Ca(OH)2

Presence of heavier molecules and toxic brominated compounds in pyrolysis products of printed circuit boards (PCB) make their use difficult. In the present work to overcome this problem PCBs were pyrolyzed in presence of catalysts such as ZSM-5 and Ca(OH)2 to study their effect on pyrolysis products. The comparison of non-catalytic pyrolysis of PCB was done with oil and gas compositions produced by both techniques. Pyrolysis experiments were done at a lab scale set-up. However, the increased concentrations of ZSM-5 were found to increase char and gases were found to be rich in CH4 and O2. The composition of oils was mainly composed of phenols, phenol derivatives and aromatic compounds, which increased with pyrolysis with ZSM-5 and Ca(OH)2. Ca(OH)2 was found effective in removing brominated compounds from oil and no halogens were observed in oil. Char produced during pyrolysis was mesoporous in nature and composed of some fractions of metals and glass fibers.