Removal of PCBs from mineral oils

The paper deals with the elimination of PCBs from dielectric and contaminated lube oils by using the KPEG process. Experimental runs at lab scale showed that the treatment is effective on both kinds of oils, but the degree of PCBs removal is higher in case of dielectric oils. The PCB elimination grade is affected by both KOH/PEG and PEG/oil ratios, and strongly by the nature of the PCB mixture. In fact, the reactivity of less chlorinated PCBs, i.e. with 3–5 chlorine atoms, is two orders of magnitude lower than that of PCBs with 5–7 chlorine atoms.