Extraction of flame retardants from electronic printed circuit board by supercritical carbon dioxide

Flame retardants are contained in electronic plastic products as an additive to avoid inflammation. In conventional incineration disposal process, it cannot be avoided producing some pernicious components. An incineration of wastes plastics may lead to production of pernicious components, which may pollute environment. As a part of chemical recycling of wastes plastics, flame retardants should be recovered. Flame retardant, triphenyl phosphate (TPPO4), from electronic printed circuit board was extracted by supercritical carbon dioxide. At temperatures ranges of 313–353 K and pressures of 10–25 MPa, the effects of CO2 flow rate, temperature and pressure on the extraction efficiency of TPPO4 were investigated. Furthermore, the effect of particle size of the material was investigated at a temperature of 343 K and pressure of 20 MPa. A larger extraction efficiency of TPPO4 was obtained at higher temperature and higher pressure. Up to 90% of extraction efficiency was obtained at extraction temperature of 343 K and at pressure of 25 MPa. Therefore, TPPO4 was efficiently extracted by using supercritical CO2 without addition of entrainer.