Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil.
Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in the presence of transformer oils was carried out in a fixed bed reactor using a 57.6 wt% Ni on silicon oxide-aluminum oxide (SiO(2)-Al(2)O(3)) catalyst. Reaction temperatures ranging 150-300 degrees C, PCBs concentrations ranging 50-200 ppm, and reaction times ranging 1-8 h were tested. At a higher reaction temperature or at a lower PCBs concentration, catalytic activity was higher and complete dechlorination of PCBs resulted even at long reaction time. Catalyst regeneration using hexane and 0.1 M sodium hydroxide (NaOH) was effective to restore the catalytic activity. Fresh, spent and regenerated catalysts were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. XRD analysis revealed growth of Ni crystallite size of the spent and the regenerated catalysts. XPS analysis showed that a considerable amount of chlorine and carbon species were deposited on the surface of the spent catalyst, which may play a role in the catalysts deactivation.
Veriansyah
Bambang
B
Energy and Environmental Research Division, Korea Institute of Science and Technology, Seoul, Korea.
Choi
Hye-Min
HM
Lee
Youn-Woo
YW
Kang
Jeong Won
JW
Kim
Jae-Duck
JD
Kim
Jaehoon
J
D000537:Aluminum Oxide / Q000737:chemistry; D002384:Catalysis; D002712:Chlorides / Q000302:isolation & purification*; D004787:Environmental Pollution / Q000517:prevention & control*; D007219:Industrial Oils / Q000032:analysis*; D056951:Photoelectron Spectroscopy; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
D002712:Chlorides; D014867:Water; D012822:Silicon Dioxide; D011078:Polychlorinated Biphenyls; D000537:Aluminum Oxide