Characterization of Polycyclic Aromatic Hydrocarbon Particulate and Gaseous Emissions from Polystyrene Combustion

Abstract

The partitioning of polycyclic aromatic hydrocarbons (PAHs) between the particulate and gaseous phases resulting from the combustion of polystyrene was studied. A vertical tubular flow furnace was used to incinerate polystyrene spheres (100-300 µm) at different combustion temperatures (800-1200 °C) to determine the effect of temperature and polystyrene feed size on the particulate and gaseous emissions and their chemical composition. The furnace reactor exhaust was sampled using real-time instruments (differential mobility particle sizer and/or optical particle counter) to determine the particle size distribution. For chemical composition analyses, the particles were either collected on Teflon filters or split into eight size fractions using a cascade impactor with filter media substrates, while the gaseous products were collected on XAD-2 adsorbent. Gas chromatography/mass spectroscopy (GC/MS) was used to identify and quantify the specific PAH species, their partitioning between the gas and particulate phases, and their distribution as a function of emission particle size. The total mass and number of PAH species in both the particulate and gas phases were found to decrease with increasing incineration temperature and decreasing polystyrene feed size, while the mean diameter of the particles increases with increasing incineration temperature and decreasing feed size. In addition, the PAH species in the particulate phase were found to be concentrated in the smaller aerosol sizes. The experimental results have been analyzed to elucidate the formation mechanisms of PAHs and particles during polystyrene combustion. The implications of these results are also discussed with respect to the control of PAH emissions from municipal wasteto-energy incineration systems.

Formation Characteristics of Aerosol Particles from Pulverized Coal Pyrolysis in High-Temperature Environments

“…In the studies of Hawley-Fedder et al 29 and Singh and Prakash, 30 it was illustrated that most PAHs are associated with soot at 800 -900°C. When the reaction temperature is higher than 900°C, a tendency for decreasing PAH yield with increasing temperature was also reported in the study of Durlak et al 31 The results of this study agree with the previous studies. The results indicate that at lower reaction temperature, more LMW PAHs will condense on aerosol particles.…”

Reactions of Methylated Naphthalenes with Hydroxyl Radicals Under Simulated Atmospheric Conditions

“…with virtuaiiy no PAHs observed at 1200 OC (24). In the emissions from combustion at lower temperatures, the percentage of PAH mass in the gas phase was subsiantially higher than in the patticulate phase (70 % vs 30 %), but at the higher temperatures, the reverse was me: at 1100 OC, about 70 46 of the PAH mass is bound with the particles, while 30 9% was in the gas phase.…”

Comparison between emissions from the pyrolysis and combustion of different wastes

“…Durlak and Biswas [21] analysed the PAH production in polystyrene combustion in a vertical furnace; the PAH yield in the gas phase and the particles decreased when increasing the temperature from 800 to 1200 8C. In addition, both the number of different PAH species and the total yields of these compounds decreased.…”