Debromination and improved phenol content in fuel oil generated from co-pyrolysis of non-metallic PCB and biomass

PCB, one of the main fractions of e-waste, is now becoming a source of pollution due to the presence of brominated flame retardants, which unleash highly toxic brominated compounds and other metals when burnt in presence of oxygen. The slow pyrolysis of PCB, CS and co-pyrolysis with different compositions have been carried out in a fixed bed reactor, for temperature up to 500 degrees C, with 10 degrees C/min heating rate. The produced oil had been analysed in GC-MS, and fuel properties of the oil were measured and compared with FAME standard. The experiments revealed that the oil yield of PCB had increased with increased amount of CS from 19.6 to 31.5% (wt%) with CS:PCB composition of 70:30. The XRF analysis confirmed increased amount of bromine compounds in char with increasing biomass where 32.29% (wt%) was found in PCB char and 58.60% with CS:PCB composition of 70:30. Conversely, bromine content in PCB oil was found to be 77 mg/100 g of sample and decreased significantly in co-pyrolysis oil products. On the other hand, co-pyrolysis increased the phenol and phenolic compounds in the oil by 78.63%, while it was only 60.67% in PCB oil. A possible reaction pathway of brominated epoxy resin of PCB, CS and co-pyrolysis of both with the compounds received in oil was proposed. The reaction pathway is the first ever reported mechanism for cotton stalk and PCB.