On the Thermal Behavior of Pyrolysis Oil Droplets

Aim of the present work is the study of the physical and chemical processes occurring during heating, vaporization and combustion of pyrolysis oils droplets. The behavior of bio-fuel oil (BFO) droplets, 400-1500 µm diameter, has been investigated by means of a drop tube furnace and an optical diagnostic system. The droplets were suspended at the exit of the furnace (Tair=1200 °C), using an exposed junction thermocouple. The phenomena, occurring during the vaporization/burning of each droplet, were followed by thermocouple measurements. Accurate sizing of the droplets was performed by means of high-resolution CCD camera. Analysis of drop's temperature data allowed identifying different phases, characteristic of the heating/vaporization/combustion process. Several samples of bio-fuel have been tested, originating from different feedstock and/or different production runs. Specific series of tests was aimed to assess both the influence of ethanol addition and the role of the main classes of compounds in the combustion of pyrolysis oil.