Reductive and oxidative combustion of polyethylene bags: Characterization of carbonaceous and nitrogenous species

This study aims to experimentally characterize the gaseous carbonaceous and nitrogenous species from the reductive and oxidant combustion of polyethylene plastic bags. The experimental device used is the tubular furnace, coupled to two gas analyzers: a Fourier transform infrared analyzer (FTIR) and a non dispersive infrared analyzer (NDIR). The gaseous products analyzed are: CO, CO2, CH4, C3H8, C2H4, C2H2, C6H6, HCN, N2O, NO, NO2 and NH3. The experiments were conducted at temperatures ranging from 800 to 1000 degrees C. The results obtained allow us to note that carbonaceous compounds are mainly emitted as carbon oxides (CO and CO2) whether you are reductive combustion or oxidative combustion. In addition: - Under reductive conditions, combustion is controlled by oxygen. The hydrocarbon most active in the formation of carbon monoxide is ethylene (C2H4) and to a lesser extent, from 900 degrees C, acetylene (C2H2). The extents we have made show that ammonia seem to be emitted during combustion with 10% of oxygen. - In an oxidative environment, there is production of C6H6 in substantial quantities, which partly explains the presence of soot and tar in the smoke exhaust ducts. The C2H4, CH4 and C2H2 are hydrocarbons most active in the formation of CO and CO2. Increasing of concentration of local oxygen from 10 to 21% for the combustion of plastic bags, favors an increase in efficiency of carbon conversion about 30%. About 99% of the carbon of the fuel is found to be converted to carbon oxides or hydrocarbons. Nitrogen monoxide (NO) is the major component among the gases measured with a conversion rate of nitrogen about 20%, three times larger than that obtained during the reductive combustion of plastic bags with 10% oxygen. (C) 2012 Elsevier B.V. All rights reserved.