PREFLAME OXIDATION CHARACTERISTICS OF METHANOL

The low-temperature slow oxidation of methanol was examined experiment ally in a constant volume stirred reactor. Initial temperatures ranged from approximately 650 to 700 K. Initial pressures of 700 Torr and be low were examined and the equivalence ratio was varied between 0.5 and 1.5. Temperature and pressure histories were obtained for methanol re acting in air and oxygen. Global indicators of reaction rate, reactivi ty, and autoignition tendency were derived from these data. The relati onship among these indicators and the effects on these indicators of i nitial temperature, initial pressure, and fuel/oxidizer mixture ratio were examined. In general, it was found that the overall reaction rate increased with increasing temperature, pressure, and equivalence rati o. Correlations were developed from the data which represent these eff ects over the range of conditions examined. In addition, chemical meas urements were made using gas chromatography to examine the reactant, s table intermediate, and product species histories and to gain insight into the oxidation mechanism at the conditions studied. The results ar e in agreement with an earlier mechanism and indicate that the basic p ath of the low-temperature oxidation of methanol proceeds via CH3OH -- > CH2OH --> CH2O --> CHO --> CO (--> CO2).