(104aw) A Study on Oxidation of ETBE by Thermal Analysis

As a high octane value material, tert-butyl ethyl ether (ETBE) is blended with gasoline up to about 10% to reduce CO₂ emission. This chemical came from biomass resource and becomes a booming industry for biofuel, e.g., its yield was increasing by 70 % in 2006. Its thermal stability should be clarified before large amount usage, especially regarding its storage and transportation. ETBE is stable, but may react with air to form peroxides. In this study, the reactivity of ETBE is scanned at elevated temperature by a heat flux calorimeter C80. It was found that ETBE is unstable at the range of 60-80 ºC, and a further significant runaway reaction occurs at above 150 ºC. The initial reaction was examined at 65 ºCby a thermal activity monitor (TAM), showing the more the volume concentration of oxygen, the more the heat of reaction. This implies that oxidation is responsible for the heat release at this temperature range. Furthermore, the thermal behavior of ETBE is studied by an Automatic Pressure Tracking Calorimeter (APTAC) under different oxygen environments. The effect of the amount of oxygen on the degree of oxidation was discussed. And the pressure rise at different temperature range was observed, in order to clarify the mechanism on how the initial reaction of ETBE can transit to the further significant consequence of a runaway occurrence.