二甲醚氧化反应及其添加剂效应

采用加速量热仪（ARC）测定了二甲醚（DME）氧化反应温度变化和活化能（Ea），考察了添加剂对DME热稳定性效应，分析热分解产物，探讨氧化反应机理. 结果表明，DME热氧化反应初始温度（To）为120 ℃，反应活化能Ea=167.3 kJ•mol-1.氧的存在是导致DME热稳定性下降重要因素，在氧化反应体系中添加Fe、Fe2O3、Al等时， To和Ea值减小，它们有促进氧化反应作用，特别是有过氧化物存在下，由于自由基的引发，显著降低DME热反应初始温度和反应活化能，抗氧剂能提高热稳定性.

Oxidation of dimethyl ether and additives effect

Initiating temperature (T_o) and activation energy (E_a) for thermal oxidation of dimethyl ether (DME) was measured with accelerating rate calorimeter (ARC)The effect of additives on DME thermal stability was studiedThe product of DME thermal decomposition was analyzed with GC MSThe results indicated that the initiating temperature of DME oxidation was 120℃, activation energy was 167.3 kJ·mol^-1 in vacuumDME stability was dramatically reduced in the presence of oxygenThe addition of Fe, Fe₂ O₃ and Al also decreased T_o and E_a of DME oxidation reaction, especially in the presence of hydrogen peroxide (H₂O₂) or other organic peroxides which can easy initiate the formation of free radicalsIn contrast, the presence of antioxidant can enhance DME thermal stability.