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Detoxification of PCBs Containing Transformer Oil by Catalytic Hydrodechlorination in Supercritical Fluids

초임계유체 내 수첨탈염소반응에 의한 PCBs가 함유된 절연유의 무해화 연구

  • Choi, Hye-Min (Department of Chemical and Biochemical Engineering, Korea University) ;
  • Kim, Jae-Hoon (Supercritical Fluid Research Laboratory, Energy & Environment Research Division, Korea Institute of Science and Technology (KIST)) ;
  • Kim, Jae-Duck (Supercritical Fluid Research Laboratory, Energy & Environment Research Division, Korea Institute of Science and Technology (KIST)) ;
  • Kang, Jeong-Won (Department of Chemical and Biochemical Engineering, Korea University)
  • 최혜민 (고려대학교 화공생명공학과) ;
  • 김재훈 (한국과학기술연구원 에너지환경연구본부 초임계유체연구실) ;
  • 김재덕 (한국과학기술연구원 에너지환경연구본부 초임계유체연구실) ;
  • 강정원 (고려대학교 화공생명공학과)
  • Published : 2009.03.31

Abstract

Catalytic hydrodechlorination of PCBs (polychlorinated biphenyls) included in the transformer oil was carried out to detoxify PCBs and to recycle the treated oil. Catalysts such as 0.98 wt% Pt and 0.79 wt% Pd on ${\gamma}$-alumina (${\gamma}-Al_2O_3$) support, 12.8 wt% Ni on ${\gamma}-Al_2O_3$, and 57.6 wt% Ni on silica-alumina ($SiO_2-Al_2O_3$) support were used for the catalytic hydrodechlorination. Various supercritical fluids such as carbon dioxide, propane and isobutane were used as reaction media. The effects of reaction temperature, reaction time, catalysts, and supercritical fluids on the catalytic hydrodechlorination were examined in detail. The detoxification degree increased in the order of Ni > Pd > Pt. This is possibly due to higher metal loading and larger metal size of the Ni catalyst. Below $175^{\circ}C,\;scCO_2$ was found as the most effective reaction media for the catalytic hydrodechlorination of PCBs included in the transformer oil.

본 연구에서는 금속담지촉매출 이용한 수첨탈염소화 반응에 의하여 절연유에 포함된 PCBs (polychlorinated biphenyls)의 무해화를 통한 절연유의 재이용 가능성을 고찰하였다. 금속담지촉매로는 0.98 wt% Pt 및 0.79 wt% Pd가 알루미나에 담지 되어 있는 촉매와 12.8 wt%의 Ni이 알루미나에 담지된 촉매 및 57.6 wt%의 Ni이 실리카-알루미나에 담지되어 있는 촉매를 이용하였다. 반응매질로서 생성물과의 분리의 용이성 및 환경측면을 고려하여 초임계이산화탄소, 초임계프로판 및 초임계이소부탄 등 초임계유체를 이용하였다. 수첨탈염소화 후 잔류 PCBs는 전자포획형 검출기가 장착되어 있는 가스크로마토그래피를 이용하여 분석하였다. 반응온도, 반응시간, 촉매 종류 및 초임계유체가 절연유 내 포함된 PCBs의 수첨탈염소반응에 미치는 영향을 자세히 조사하였다. 용매를 사용하지 않을 경우 탈염소화반응은 Ni > Pd > Pt의 순으로 빠르게 진행되었으며 이는 담지된 금속의 양 및 금속입자의 크기에 기인한 것으로 생각된다. 반응온도가 $175^{\circ}C$ 이하에서 초임계이산화탄소가 탈염소화반응에 가장 효과적인 매질인 것을 확인하였다.

Keywords

References

  1. Breivik, K., Sweetman, A., Pacyna, J. M., and Jones, K. C, "Toward a Global Historical Emission Inventory for Selected PCB Congeners: a Mass Balance Approach 1. Global Production and Consumption," Sci. Total. Environ., 290, 181-198 (2002). https://doi.org/10.1016/S0048-9697(01)01075-0
  2. Seok, J., Seok, J., and Hwang, K. Y., "Thermo-chemical Destruction of Polychlorinated Biphenyls (PCBs) in Waste Insulating Oil," J. Hazard Mater., 124(1-3), 133-138 (2005). https://doi.org/10.1016/j.jhazmat.2005.04.035
  3. Wu, W., Xu, J., Zhao, H. M., Zhang, Q., and Liao, S. J., "A Practical Approach to the Degradation of Polychlorinated Biphenyls in Transformer Oil," Chemosphere, 60(7), 944-950 (2005). https://doi.org/10.1016/j.chemosphere.2004.11.079
  4. Kastanek, F., and Kastanek, P., "Combined Decontamination Processes for Wastes Containing PCBs," J. Hazard. Mater., 117(2-3), 185-205 (2005). https://doi.org/10.1016/j.jhazmat.2004.09.026
  5. Murabayashi, M., and Moesta, H., "Thermodynamic Study on the Reduction of the Polychlorinated Dibenzo-para-dioxins and Dibenzofurans in Incinerator Exhausts," Environ. Sci. Technol, 26(4), 797-802 (1992). https://doi.org/10.1021/es00028a020
  6. Erickson, M. D., Swanson, S. E., Flora, J. D., and Hinshaw, G. D., "Polychlorinated Dibenzofurans and Other Thermal Combustion Products from Dielectric Fluids Containing Polychlorinated-biphenyls," Environ. Sci. Technol, 23(4), 462-470 (1989). https://doi.org/10.1021/es00181a012
  7. Murena, F., Schioppa, E., and Gioia, F., "Catalytic Hydrodechlorination of a PCB Dielectric Oil," Environ. Sci. Technol, 34(20), 4382-4385 (2000). https://doi.org/10.1021/es000015x
  8. Keane, M. A., "A Review of Catalytic Approaches to Waste Minimization: Case Study - Liquid-phase Catalytic Treatment of Chlorophenols," J. Chem. Technol. Biotechnol, 80(11), 1211-1222 (2005). https://doi.org/10.1002/jctb.1325
  9. Sajiki, H., Kume, A., Hattori, K., Nagase, H., and Hirota, K.,"Complete and Truly Catalytic Degradation Method of PCBs Using Pd/C-Et3N System under Ambient Pressure and Temperature," Tetrahedron Lett, 43(40), 7251-7254 (2002). https://doi.org/10.1016/S0040-4039(02)01620-9
  10. Murena, F., and Schioppa, E., "Kinetic Analysis of Catalytic Hydrodechlorination Process of Polychlorinated Biphenyls (PCBs)," Appl. Catal. B., 27(4), 257-267 (2000). https://doi.org/10.1016/S0926-3373(00)00157-0
  11. Gomez-Sainero, L. M., Seoane, X. L., Fierro, J. L. G., and Arcoya, A., "Liquid-phase Hydrodechlorination of $CCI_4$ to $CHCI_3$ on Pd/carbon Catalysts: Nature and Role of Pd Active Species," J. Catal., 209(2), 279-288 (2002). https://doi.org/10.1006/jcat.2002.3655
  12. Pina, G., Louis, C, and Keane, M. A., "Nickel Particle Size Effects in Catalytic Hydrogenation and Hydrodechlorination: Phenolic Transformations Over Nickel/silica," Phys. Chem., 5(9), 1924-1931 (2003). https://doi.org/10.1039/b212407f
  13. Gomez-Quero, S., Cardenas-Lizana, F., and Keane, M. A., "Effect of Metal Dispersion on the Liquid-phase Hydrodechlorination of 2,4-Dichlorophenol over $Pd/Al_2O_3$," Ind. Eng. Chem. Res., 47(18), 6841-6853 (2008). https://doi.org/10.1021/ie0716565
  14. Keane, M. A., Park, C, and Menini, C, "Structure Sensitivity in the Hydrodechlorination of Chlorobenzene over Supported nickel," Catal. Lett., 88(1-2), 89-99 (2003). https://doi.org/10.1023/A:1023599203073
  15. Fujita, S., Bhanage, B. M., Ikushima, Y., and Arai, M., "Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol in the Presence of Methyl Iodide and Base Catalysts under Mild Conditions: Effect of Reaction Conditions and Reaction Mechanism," Green Chem., 3(2), 87-91 (2001). https://doi.org/10.1039/b100363l
  16. Sarrade, S., Schrive, L., Gourgouillon, D., and Rios, G. M., "Enhanced Filtration of Organic Viscous Liquids by Supercritical CO2 Addition and Fluidification Application to Used Oil Regeneration," Purif. Technol, 25(1-3), 315-321 (2001). https://doi.org/10.1016/S1383-5866(01)00058-2
  17. Pomier, E., Delebecque, N., Paolucci-Jeanjean, D., Pina, M., Sarrade, S., and Rios, G. M., "Effect of Working Conditions on Vegetable Oil Transformation in an Enzymatic Reactor Combining Membrane and Supercritical CO2," J. Supercrit. Fluids, 41(3) 380-385 (2007). https://doi.org/10.1016/j.supflu.2006.12.010