Extraction of polybrominated diphenyl ethers from plastic solution by supercritical carbon dioxide anti-solvent

A new recycling process on supercritical CO2 extraction of PBDEs from waste HIPS plastic was developed in this paper, the influence laws of temperature, pressure, volume of supercritical CO2 and deca-BDE concentration on the separating efficiency were investigated, the measures for reducing the effect of deca-BDE concentration on the separating efficiency were proposed. The experimental results showed that the suitable supercritical condition was 65 degrees C, 20MPa. the optimum volume ratio of supercritical CO2 to HIPS solution was 2:1, E and the deca-BDE particles can be removed by a centrifuge process at speed of 10000 r/min and at 30 degrees C. It was found that over 97 % of PBDEs was successfully removed and the concentration of PBDEs residual in HIPS was reduced to lower than 0.1% (dry) by this recycling process. (C) 2012 Selection and/or peer-review under responsibility of Basel Convention Coordinating Centre for Asia and the Pacific and National Center of Solid Waste Management, Ministry of Environmental Protection of China.