Emission Characteristics of PCDD/Fs, PCBs, Chlorobenzenes, Chlorophenols, and PAHs from Polyvinylchloride Combustion at Various Temperatures

Abstract

The effect of temperature on polyvinylchloride (PVC) combustion using a downstream tubular furnace was investigated for the formation of polycylcic aromatic hydrocarbons (PAHs) and chlorinated compounds. As the temperature increased, higher levels of PAHs were generated. Chlorinated compounds reached a peak at 600°C, with low emissions recorded at 300 and 900°C. There was a close correlation (R 2 ϭ 0.97) among polychlorinated biphenyls (PCBs), hexachlorobenzene, pentachlorobenzene, and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). PAHs at all temperatures were analyzed in the gas phase. PCDD/Fs and PCBs were emitted as a solid phase at 300 and 600°C and as a gas phase at 900°C. For some PAHs, chlorobenzenes, and PCDD/Fs, a mathematical equation between the gas and solid phase and the reciprocal temperature in semilog proportion was derived. The proposed equation, which is log (amount in gas phase/amount in solid phase) ϭ ϪA/T ϩ B, where T is the temperature of the furnace and A and B are constants, for these species relating their gas/solid distributions showed a good relationship.

Semivolatile and volatile compounds from the pyrolysis and combustion of polyvinyl chloride

“…Kim et al [13] also found an increase of the 16 main PAH yields with temperature during combustion of 0.5 g PVC with 2 L/min air in a downstream vertical tubular furnace at temperatures of 300, 600 and 900 8C: about 800, 3500 and 5000 ppm, respectively. In that work, the high yield for phenanthrene (1400 ppm maximum), higher than that of naphthalene (1100 ppm maximum), was remarkable.…”

“…Results obtained are sometimes difficult to compare because of the variety of operating conditions and systems used. But there is not much research on concurrent emission analysis of PAHs, ClBzs, ClPhs and PCDD/Fs from the pyrolysis and combustion of PVC at different temperatures [13]. The aim of this work is to provide a comprehensive laboratory study of the pyrolysis and combustion products of pure PVC at different temperatures, mainly focusing on a detailed analysis of the great amount of PAHs generated by pyrosynthesis reactions and the chlorine aromatic compounds evolved.…”

“…After that, the extracts were concentrated in a rotary evaporator and under a gentle stream of nitrogen up to 0.3 mL. 13 C labeled compounds included in the US EPA 1613 method were used to quantify (20 mL of labeled-compound spiking solution (LCS) added prior to extraction) and to calculate final recovery (10 mL of internal standard solution (ISS) added to the final volume). Recoveries were rather acceptable (70% mean value).…”

“…Benzene, which is a carcinogenic compound, is one of the main products resulting from the thermal degradation of PVC [3][4][5]. Other substituted monoaromatic and polyaromatic hydrocarbons (PAHs) are reported to appear in pyrolysis and combustion of PVC at different temperature ranges [5][6][7][8][9][10][11][12][13]. Some PAHs are classified in EPA's National Toxic Inventory as hazardous air pollutants (HAP), and even, seven of them are thought to be probable human carcinogenic compounds [14].…”

“…Apart from hydrogen chloride, chlorinated aromatic compounds are evolved during pyrolysis or combustion of PVC, such as light chlorinated aliphatic hydrocarbons [5], chlorinated PAHs [15], chlorobenzenes (ClBzs) [6,16,13], chlorophenols (ClPhs) [13], chlorobiphenyls (PCBs) [13,17], polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) [11,13,[17][18][19][20][21][22].…”