Characterization of the burning behavior and gaseous emissions of pine needles in a cone calorimeter – FTIR apparatus

• Cone calorimeter was used to study the thermal decomposition of Maritime pine needles.
• Comparison between piloted and non-piloted ignition of the pine needles.
• Characterization of the thermal behavior of the fuel bed.
• Analysis of the gaseous emissions by using FTIR.
• Calculation of emission yields and carbon atomic balance.

The paper presents flammability studies related with the combustion of Maritime pine needles (pinus pinaster, representative of Mediterranean vegetation) in a cone calorimeter (CC) under air atmosphere with piloted ignition and self-ignition for different heat fluxes, from 10 to 50 kW m−2. The Main objective is to measure the yields of the gaseous emissions released during the experiments because one of the major risks during the fire is from the smoke and products of combustion. Identification of exhaust gaseous compounds and concentration measurements have been done by FTIR, NDIR, chemiluminescence and paramagnetism gas analyzers for assessing the fire behavior and identifying the decomposition chemistry. Among the 15 different compounds simultaneously analyzed, the yields of CH4, CO2, CO, H2O, NO and O2 have been quantified. HCN and light-weight hydrocarbons (C2H2, C2H4, C3H6 and C3H8) have been observed at low concentrations.The results show that carbon dioxide and water are the main emissions during the experiments. Also, the carbon balance shows that about 5% of the carbon released as carbon monoxide and hydrocarbon whatever the external heat flux chosen. Moreover, flammability parameters such as Mass Loss, Mass Loss Rate (MLR) and Time to Ignition (tig) have been determined for each condition during the experiments. Pine needles is considered often as a thermally thin material. However, the bed of pine needles behaves as a thermally thick material in the conditions tested.