New Methodology for the Application of a TGF-FTIR to Study Low Temperature Treatment of Waste Oil.

A new methodology was developed using a Thermo-Gravi-metric Furnace coupled to a Fourier Transform Infrared Spectrometer (TGF-FTIR) to study the low temperature treatment of waste lubricating oils. The sample was heated from room temperature to a final temperature of 1,000 °C at an initial heating rate of 3 °C/min, to slow down the oxidative pyrolysis process allowing for the events taking place to be observable. It was found that the majority of the process in terms of weight loss and gas-phase evolution was over by 650 °C, and thus, the remainder of the sample heating was accomplished at a rate of 5 °C/min. The sample was kept at a temperature of 1,000 °C for 60 minutes in order to allow the remaining solid material to achieve a state of equilibrium (necessary for the solid morphological study). The applicability of TGF-FTIR using this methodology to research in the environmental field was proven to be quite successful, since it allowed for precise control over environmental conditions while simultaneously allowing for data gathering on both sample weight and gas-phase evolution. The developed methodology proved to be reliable, giving repeatable results. The information gathered was used to understand and explain the evolution of the waste oil from initial liquid state to a final solid ash state. It was accomplished in four steps, including (1) release of moisture/light hydrocarbons, (2) bulk volatilization of hydrocarbons, (3) solid material deposition, and (4) solids oxidation.