FORMATION AND EMISSION OF PCDDS PCDFS IN THE PETROLEUM REFINING INDUSTRY

The formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) during a variety of combustion and chemical manufacturing processes has been well documented. The petroleum refining industry, previously unrecognized as a source of PCDDs and PCDFs, has recently been found to emit these compounds. The PCDDs and PCDFs are formed during the regeneration of spent catalyst material. In stack emission and wastewater effluent samples collected from different petroleum refineries, a series of chlorinated dioxins and furans were identified. The congener distribution patterns observed in these samples were similar to those previously found in flyash samples collected from various municipal waste incinerators. Low parts-per-quadrillion levels of PCDDs and PCDFs have been identified in internal effluent streams. The concentrations of PCDDs and PCDFs in the stack gas samples are typically in the low ng/m3. © 1990.