Analysis by GC-MS of monocyclic and polycyclic aromatic hydrocarbons in thermolysed waste products

Abstract

Thermolysis is a new thermal decomposition process of waste products. This process involves a partial vacuum and oxygen free environment inerted under a stream of nitrogen. This technique allows for the recuperation and valorisation of recyclable materials without producing any dust or clinkers. Wastes decomposition is carried out in an oven in presence of recycled gas of thermolysis, circulating in a continuous flow, at 650 °C. Gas issued from thermolysis are cooled and treated: gaseous fraction is directly used as energy source and, water and hydrocarbon fractions are collected after decantation on a lamellar layer separator. Hydrocarbons are conditionned to be used in the thermal cycle as an energy source. So it is important to know the nature and the rates of these hydrocarbons in order to anticipate the degree of risk for the environment and to evaluate the best conditions of their recycling. The aim of this study was to analyse these hydrocarbons, obtained after thermolysis of waste compounds. Monoaromatic hydrocarbons (MAH) and polyaromatic hydrocarbons (PAH) are known to be toxic compounds, bronchopulmonary and cutaneous irritants, with risks of carcinogenicity and mutagenicity. Cases of cutaneous, bronchopulmonary and vesical tumors have been linked with aromatic hydrocarbons. The degree of risk depends on the compounds, benzo[a]pyrene is shown to be the most toxic [1,2].