TD24 determination for mono-nitration products of toluene

doi:10.3969/j.issn.0438-1157.2014.11.024

Abstract

Abstract: To determine the temperature of sample 1 (toluene mono-nitration crude product: mononitrotoluene with a little mixed acid) and sample 2 (pure mononitrotoluene product, MNT) T_D24, at which the required time to reach maximum rate of temperature rise under adiabatic condition is 24 hours, and to obtain the thermal decomposition characteristics of these products, differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) were employed to test the thermal behaviors of the two samples. By kinetic analysis for dynamic data obtained by DSC in dynamic mode, the T_D24 determined for samples 1 and 2 are (246.1±4.5)℃ and (257.9±3.6)℃, respectively. As a comparison, the values of T_D24 for sample 1 and 2, determined by ARC under adiabatic condition, are 241.5℃ and 256.4℃, respectively. Therefore, the T_D24 values derived from dynamic data are in good agreement with those by ARC, which means that the results derived from DSC are of large reliability and can be used as a reference for engineering applications. Meanwhile, a comparison for the results of sample 1 and 2 indicates that the thermal hazard of MNT with a little mixed acid is higher than that of pure one.

Key words: safety, stability, kinetics, T_D24, mononitrotoluene, differential scanning calorimetry, adiabatic calorimetry

摘要： 为获取甲苯一段硝化未经碱洗产物(样品1:一硝基甲苯+少量混酸)及碱洗后的纯品产物(样品2:一硝基甲苯)在绝热条件下最大温升速率达到时间为24 h所对应的引发温度T_D24,并了解其热分解特性,首先采用差示扫描量热仪(DSC)测试了两种样品不同升温速率下的动态DSC数据,分析获得了样品的机理函数、活化能和指前因子,进而推导出两个样品的T_D24分别为(246.1±4.5)℃和(257.9±3.6)℃.然后利用绝热加速度量热仪(ARC)对此进行了实验验证,得到绝热条件下样品1和2的T_D24分别为241.5℃和256.4℃.上述结果表明,DSC推导的T_D24结果与ARC结果几乎一致.这表明根据动态DSC测试参数推导的T_D24具有一定的可靠性,可以作为工程应用的参考;就甲苯一段硝化产物而言,含酸体系的热分解危险性更高.

关键词: 安全, 稳定性, 动力学, T_D24, 一硝基甲苯, 差示扫描量热, 绝热量热

CLC Number:

ZHOU Yishan, CHEN Liping, CHEN Wanghua, YANG Ting, ZHANG Caixing, YIN Ruili. T_D24 determination for mono-nitration products of toluene[J]. CIESC Journal, 2014, 65(11): 4383-4391.

周奕杉, 陈利平, 陈网桦, 杨庭, 张彩星, 尹瑞丽. 甲苯一段硝化产物T_D24的获取[J]. 化工学报, 2014, 65(11): 4383-4391.

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