Destruction of organic Cl and Br compounds through incineration enhanced by alkali and alumina addition

Abstract

Thermochemical destruction of organic Cl and Br compounds in a combustion system was studied. A Cl compound and three Br compounds, namely, 1,2,3,4-tetrachlorobenzene (TeCB), 1,2,4,5-tetrabromobenzene (TeBB), tetrabromobisphenol A (TBBPA), and decabromodiphenyl ether (DBDE) were used. The samples on a boat were combusted at 600 °C followed by gas combustion at 800, 900, and 1,100 °C. An off-gas was adsorptively collected and introduced into a Cl and Br detector by thermal desorption. The destruction efficiency was evaluated using the organic halogen residual ratio (OX-RR) (μg g−1). Halogenated benzene compounds such as TeCB and TeBB were destructed moderately (OX-RR for these compounds at 800, 900 and 1,100 °C was 112, 35 and 32 μg g−1 and 258, 57 and 48 μg g−1, respectively); on the other hand, the destruction of TBBPA and DBDE, namely fire retardants, was difficult (OX-RR at 800 °C for these compounds was 7,159 and 718 μg g−1, respectively). Addition of an alkali and an alumina to a sample enhanced the destruction of organic compounds drastically by several times. This destruction enhancement occurred at temperature as low as 600 °C. Such chemical halogen control is effective to thermal destruction of organic Cl and Br compounds.