Capturing approach for the toxic bromides generated in low-temperature pyrolysis of brominated resin

In order to avoid secondary pollution during recovery of brominated resin, additives had been proposed for capturing bromine in high-temperature (700 °C) pyrolysis of brominated resin. However, the capture capacity and mechanism of CaCO3 and activated carbon to the generated micromolecule bromides was still unknown in the low-temperature (300 °C) pyrolysis process, in which brominated resin could realize debromination. This paper accurately analyzed the capture capacity and mechanism of CaCO3 and activated carbon to bromides by quantum chemistry calculation and wet experiments. CH3Br was considered as the main bromide in the low-temperature pyrolysis. The capture process of CaCO3 to CH3Br turned to be physisorption, and one CaCO3 particle with the size of 0.5 μm could captured 4.53 × 10−22 mol CH3Br. The capture capacity of CaCO3 to CH3Br is only 2.37 × 10−9 mol/g. Furthermore, the capture capacity of activated carbon to CH3Br was 8.50 × 10−5 mol/g. The mass of activated carbon needed to capture 4.03 × 10−4 mol CH3Br generated of 1 g brominated resin in low-temperature pyrolysis was 3.68 g. This paper contributes scientific information and approach to the safe resource recovery of waste brominated resin.