NO_2-O_2氛围下碳黑颗粒氧化特性研究

A Study on the Characteristics of the Oxidation of Carbon Black in the Atmosphere of NO_2-O_2

利用热重分析仪,先后在O_2及NO_2-O_2氛围下对2种模型碳黑颗粒(Printex-U及Monarch-1300)进行了非等温氧化试验,研究NO_2对碳黑颗粒氧化特性的影响。研究表明,在中低温范围(240～600℃)内,NO_2的添加对碳黑颗粒氧化起到显著的促进作用;当温度较高(大于600℃)时,NO_2对碳黑颗粒氧化的促进效果不再显著。NO_2对碳黑颗粒起燃温度的影响效果随升温速率的升高而减小。2种碳黑颗粒在不同氧化氛围(O_2和NO_2-O_2氛围)下的最大氧化速率温度、燃尽温度均随升温速率的降低而减小。利用Flynn-Wall-Ozawa法计算出的动力学参数结果表明,2种模型碳黑颗粒在NO_2-O2氛围下的活化能值均低于在O_2氛围下的活化能值,Printex-U碳黑颗粒的氧化活性高于Monarch-1300碳黑颗粒。

The non-isothermal oxidation experiments of two kinds of carbon black particles（Printex-U and Monarch-1300） under different heating rates were carried out in O2 atmosphere and NO2-O2 atmosphere by using thermal gravimetric analyzer（TGA） to explore the effect of NO2 on the oxidation characteristics of carbon black. The results show that the addition of NO2 significantly enhanced the oxidation of carbon black in a fairly low temperature range of 240～600 ℃, whereas the NO2 effects appeared to be insignificant in the higher temperature range（above 600°C）. Meanwhile, the effect of NO2 on the light-off temperature of carbon black decreased as the heating rate increased. The maximum oxidation rate temperature and burn-out temperature of the two kinds of carbon black particles in different oxidizing atmospheres（O2 atmosphere and NO2-O2 atmosphere） all decreased as the heating rate decreased. Thermodynamic parameters of carbon black particles were calculated by Flynn-Wall-Ozawa method. The results show that the apparent activation energies obtained were lower with 500 ppm NO2 and the oxidation activity of Printex-U carbon black was higher than that of Monarch-1300 carbon black.