Extraction of brominated flame retardants with supercritical CO2

• Main Author: Ang, Li Yi
• Other Authors: Alex Yan Qingyu
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/139654
• Institution: Nanyang Technological University

Due to the pressing issue related to the toxic effects produced by traditional disposal techniques of waste electric and electronic equipment (WEEE), a safer and non-toxic method of extracting Brominated Flame Retardants (BFR) from WEEE is required. In this study, a green extraction technique, known as the supercritical fluid extraction (SFE) technique, was applied, where carbon dioxide is used as the fluid. The SFE technique is highly recommended for this purpose due to its high extraction efficiency exhibited in previous studies. The absorbance of the extractants of BFR is then measured by the Fourier-Transform Infrared (FTIR) spectroscopy technique. Using a FTIR spectrometer, the absorbance of the extractants of selected BFR sample can be achieved by applying the Beer’s Lambert Law, where calculated absorbance value can be converted to concentration. In the final part of the study, recrystallization of BFRs in ScCO2 by different operational protocols were studied and examined using a characterization technique known as Scanning Electron Microscopy (SEM), for visual observation of changes in the morphology of BFR crystals after completing the recrystallization process. The comparison in morphology between BFR crystals extracted from both ScCO2 and solvent evaporation techniques were discussed as well.