硫铁化物氧化自燃的动力学分析

摘要

In order to study the spontaneous combustion tendency of iron sulfides in the storage tank of sulfur containe d oil, the thermal analysis experiments of iron sulfides samples were implemented on STA8000 synchronous thermal analyzer under the conditions of different heating rates as 10, 15, 20℃/min and different air flows as 15, 20, 25 mL/min, and the sponta-neous combustion characteristics of the samples were investigated through the obtained TG-DSC curves.On this basis, the data of thermal gravimetric analysis were processed by using different reaction mechanism functions according to Coat model. The results showed that the oxidation process of iron sulfides accorded with the kinetic mechanism of third order reaction un-der these experimental conditions.Meanwhile, the apparent activation energy of iron sulfides under different heating rates and air flows were obtained.In the temperature interval of 560-746℃, the value of activation energy decreased obviously and the spontaneous combustion tendency increased with the increase of heating rate and air flow.The results can provide the theoretical reference for the prevention and control of fire and explosion accidents caused by the spontaneous combustion of i-ron sulfides.%为研究含硫油品储油罐中硫铁化物的自燃倾向性,采用STA8000同步热分析仪对10,15,20℃/min等不同升温速率和15,20,25 mL/min等不同空气流量下的硫铁化物进行试验,并通过获得的TG-DSC曲线研究试样的自燃特性;在此基础上,根据Coat模型,利用不同反应机理函数对热重数据进行分析.结果表明:该试验条件下,硫铁化物的氧化进程符合三级反应动力学机制;得出了硫铁化物在不同升温速率和空气流量下的表观活化能;在560～746℃温度区间内,随着升温速率的增加,空气流量的加大,活化能数值明显减小,自燃倾向性增大.研究结果可为预防和控制因硫铁化物自燃引发的火灾、爆炸事故提供理论参考.