Identification of the Released and Transformed Products during the Thermal Decomposition of a Highly Chlorinated
Shanzhi Xin1,2, Wei Gao1,3, Yawei Wang1,4,3
1State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China.
Abstract:
As plasticizers and flame retardants, highly chlorinated paraffin (CP70) and related products will experience thermal processes during their lifecycle stages. However, the thermal transformation data for CP70 is limited. In this study, we investigated the release and transformation of chlorinated and unchlorinated products during the thermal decomposition of CP70. Large quantities of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) and unsaturated analogues (Cl-polyenes or chlorinated olefins) as well as toxic chlorinated aromatic hydrocarbons were formed synergistically under different thermal conditions. The yield of SCCPs increased gradually in the gas phase, while it decreased in the residue at 200-400 °C. SCCPs can be transformed further and generated mostly polychlorinated biphenyls (PCBs). Oxygen promoted the thermal transformation of SCCPs and MCCPs and decreased the yield in the gas phase at >400-500 °C. In contrast, the yield of both SCCPs and MCCPs increased notably under N2 at 800 °C. Chlorobenzene (CBz), PCBs, and polychlorinated naphthalenes (PCNs) were the main chlorinated aromatic hydrocarbons and obtained a maximum yield at 500-600 °C. The present findings indicate that CP70-containing materials may synergistically generate SCCPs, MCCPs, and other toxic chlorinated compounds during their life cycles.
More Related Videos
07:25Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids
Published on: January 9, 2017
07:07Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes
Published on: April 7, 2017
Related Concept Videos
Synthesis and Decomposition Reactions
Radical Substitution: Allylic Chlorination
Dynamic Equilibrium
Bacterial Transformation
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
Energy-releasing Steps of Glycolysis
The first energy-releasing step—the 6th step of glycolysis...
Thermal expansion and Thermal stress: Problem Solving
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55...
