混酸中甲苯半间歇硝化过程的危险性研究

为了解甲苯在混酸中硝化的危险性,用差示扫描量热法(DSC)测试甲苯、混酸及一硝基甲苯的热分解情况,用反应量热仪(RC1e)研究搅拌速度、温度及硝酸过用率3因素对目的反应的影响。结果表明,混酸分解温度最低,而当目的反应的3因素出现异常,以及反应过程中发生冷却失效时,均可导致硝化反应体系不稳定,此时若不停止加料,并采取措施,易引起混酸的分解,进一步可引起一硝基甲苯的分解,导致严重后果。

Study on the Hazards of Semi-batch Nitration Process of Toluene in Mixed Acids

To find out the thermal hazards in the semi-batch process of toluene nitration with mixed acid in detail, the pyrolytic decomposition of toluene, mixed acid and mono-nitrotoluene were tested by using Differential Scanning Calorimetry (DSC), and the effect of the three factors of stirred rate, reaction temperature and the mole ratio of nitric acid on destination reaction was studied by Reaction Calorimeter (RC1e). It is concluded that the decomposition temperature of mixed acid is lowest. Both the abnormality of the three factors and the malfunction of the cooling system in the reaction can cause the instability of the reaction system. If the feeding of reaction material is not stopped and corresponding measures are not taken at that time, it is apt to cause the decomposition of mixed acid, and even the decomposition of mono-nitrotoluene with the situation worsening, which eventually leads to a serious disaster.