Thermo-chemical destruction of polychlorinated biphenyls (PCBs) in waste insulating oil.
The feasibility of thermo-chemical destruction of polychlorinated biphenyls (PCBs) was investigated using a batch reactor and two different (vertical and horizontal) types of continuous reactor. A simple batch reactor was first designed and constructed to examine applicability of thermal-chemical destruction of PCBs. It was evidenced from the batch test results that the destruction of PCBs in the insulating oil (40% PCBs, w/w) was accomplished via abiotic dechlorination and mineralization of PCBs with quicklime at 600 degrees C under nitrogen environment. PCB destruction efficiencies were obtained about 99.95%. The reaction was exothermic resulting release of heat by which the reactor temperature suddenly increased up to 750 degrees C at the incipient 30 min of the experiment. Two major end products, CaCl2 and carbon, were identified. For a practical purpose, two continuous reactors were developed and tested. The observed continuous test results indicate that over 99.99% of PCB destruction efficiencies were achieved when excess quicklime (>3Ca:1Cl2 as a molar basis) was used. Specifically, the horizontal continuous reactor was suitable in view of ease of solid transfer, which is essential for complete destruction of PCBs and for full-scale applications.
Seok
Jonghyuk
J
Department of Chemical & Environmental Technology, Inha Technical College, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-752, Korea. seokj2@inhatc.ac.kr
Seok
Jongwon
J
Hwang
Kyung-Yub
KY
D004867:Equipment Design; D019544:Equipment Failure Analysis; D017745:Incineration / Q000295:instrumentation / Q000379:methods*; D007219:Industrial Oils; D007220:Industrial Waste / Q000517:prevention & control*; D009994:Osmolar Concentration; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D013696:Temperature
D007220:Industrial Waste; D011078:Polychlorinated Biphenyls