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

Abstract

Emissions evolved from the pyrolysis and combustion of poly(vinyl chloride) were studied at four different temperatures (500, 700, 850 and 1000 8C) in a horizontal laboratory tubular quartz reactor in order to analyse the influence of both temperature and reaction atmosphere on the final products from thermal and oxidative reactions. It was observed that the CO 2 /CO ratio increased with temperature. Methane was the only light hydrocarbon whose yield increased with temperature up to 1000 8C. Benzene was rather stable at high temperatures, but in general, combustion at temperatures above 500 8C was enough to destroy light hydrocarbons. Semivolatile hydrocarbons were collected in XAD-2 resin and more than 160 compounds were detected. Trends on polyaromatic hydrocarbon (PAH) yields showed that most had a maximum at 850 8C in pyrolysis, but naphthalene at 700 8C. Formation of chlorinated aromatics was detected. A detailed analysis of all isomers of chlorobenzenes and chlorophenols was performed. Both of them reached higher total yields in combustion runs, the first ones having a maximum at 700 8C and the latter at 500 8C. Pyrolysis and combustion runs at 850 8C were conducted to study the formation of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs). There was more than 20-fold increase in total yields from pyrolysis to combustion, and PCDF yields represented in each case about 10 times PCDD yields. #

Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

“…Pyrolysis and combustion runs were conducted with both samples at two different temperatures (600 and 850 ºC), using a tubular quartz reactor located inside a horizontal laboratory furnace described in detail elsewhere (Aracil et al, 2005a). For each run, synthetic air (combustion runs) or nitrogen (pyrolysis runs) was introduced in parallel flow with respect to the sample, at a constant flow of 300 mL/min (1 atm, 20 ºC).…”

Comparison between emissions from the pyrolysis and combustion of different wastes

“…PVC resin Etinox-450 free of additives obtained by emulsion polymerization: had a medium molecular weight (104,000 and 40,000 for Mw and Mn, respectively) and very small particle size, ranging from 1.4 to 24.4 mm [4].…”

“…After collecting the exit gas for 5 min, the holder was removed from the furnace. More details regarding the experimental procedure can be found elsewhere [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

Emissions of brominated compounds and polycyclic aromatic hydrocarbons during pyrolysis of E-waste debrominated in subcritical water

“…This equipment has been previously described in detail (Aracil et al, 2005;Moltó et al, 2011). For each run, nitrogen was introduced at a constant flow of 300 mL min −1 in parallel to the sample movement.…”