Dry Sorption of Bromine Compounds in Pyrolysis Gas Derived from Brominated Flame Retardant Plastic with Na₂CO₃

Abstract

Decomposition of methyl bromide (CH₃Br) and bromobenzene (C₆H₅Br) was investigated along with Br sorption from CH₃Br or C₆H₅Br by Na₂CO₃ sorbent.
Under a CH₃Br-N₂ atmosphere without Na₂CO₃, results showed that HBr and C₂H₂ were generated by thermal decomposition of CH₃Br at temperatures greater than 673K. Similarly, under C₆H₅Br-N₂ atmosphere without Na₂CO₃, both HBr and C₆H₆ were generated at temperatures higher than 673K.
The presence of Na₂CO₃ sorbent was found to promote decomposition of CH₃Br and C₆H₅Br at temperatures of 673-973K. During CH₃Br and C₆H₅Br decomposition in the presence of Na₂CO₃, the formation of NaBr was observed. It was therefore concluded that Br gaseous compounds formed by the decomposition of CH₃Br and C₆H₅Br were absorbed on Na₂CO₃. Regarding the Br absorption ratio on Na₂CO₃ sorbent at a temperature of 873K, the Br absorption ratios on Na₂CO₃ under CH₃Br-N₂ and C₆H₅Br-N₂ atmospheres were, respectively, 0.50 and 0.29.