抗氧剂对燃料NNJ-150热氧化安定性的影响

Effects of Antioxidant on Thermal-Oxidation Stability of Fuel NNJ-150

在200℃和饱和溶解氧状态的加速氧化条件下,采用静态法分别考察了2,6-二叔丁基对甲基酚(BHT)和茶多酚(TPP)两种酚型抗氧剂作用下的吸热型碳氢燃料NNJ-150的热氧化安定性。测定热氧化沉积物的量和氧化燃料吸光度值随时间及温度的变化。结果表明,加入BHT和TPP后,沉积物量减少,颜色深度下降,抗氧剂可以延长燃料的氧化诱导期,提高热氧化安定性温度。相对而言,BHT更适合于较低温度和较长时间范围内使用,而TPP更适合于较高温度和较短时间范围内使用。结合燃料的液相自氧化机理,可以解释实验的变化规律和酚型抗氧剂的作用机制。同时,以BHT为例,选择抗氧剂的不同加入量,检验了燃料热氧化安定的长效性。BHT的加入明显地延长了吸热型碳氢燃料NNJ-150的热氧化安定期,150℃时有效作用期可达近400h。

Effects of two kinds of phenol antioxidants, butylated hydroxytoluene （BHT） and tea polyphenols （TPP）, on the thermal-oxidation stability of an endothermic hydrocarbon fuel NNJ-150 were tested by a static state method under the accelerating oxidation condition with saturated dissolving oxygen at 200℃. Variations of thermal-oxidation deposit and light absorbance of the oxidized fuels versus oxidation time or temperature were measured respectively. The results show that the amount of the thermal-oxidation deposit decreases and the color-change of the oxidized fuel is relatively small when the fuel contains the antioxidant of BHT or TPP. The antioxidant added can prolong the oxidation induction period of the fuel and increase its thermal stable temperature. It is also found that BHT is more appropriate for the application under lower temperature and wider using time period, while the TPP is suitable for higher temperature and shorter using time period. According to the mechanism of auto-oxidation of liquid hydrocarbon fuels, the experimental phenomena and effects of the antioxidants were explained. Furthermore, the prolongation of the thermal-oxidation stability was investigated for the fuels with different concentrations of BHT as antioxidant. It is clear that BHT can prolong the stable period of the endothermic fuel NNJ-150 against thermal-oxidation. At 150℃, the effective stable period can be prolonged to about 400 hours by adding the antioxidant of BHT.