氢氧化铁引发含硫油品储罐自燃的动力学机制

Kinetics mechanism of spontaneous combustion of oil tank containing sulfur caused by Fe(OH)_3

含硫油品储罐自燃火灾事故的根本原因是罐壁铁锈被含硫油品腐蚀生成具有自燃倾向性的腐蚀产物,这些腐蚀产物自燃而引起油罐火灾。通过硫化试验模拟储罐内壁氢氧化铁硫化产物,对其进行热分析试验,应用非模型法和'主曲线法'确定氢氧化铁硫化产物的动力学机制。结果表明,氢氧化铁硫化产物在氧化反应阶段的热重曲线可分为两个主要的失重阶段:第一失重阶段符合随机成核和随后生长反应动力学反应机制,其模型函数为g(a)=[-ln(1-a)]0.673 1,平均活化能E=124.25 kJ/mol,指前因子A=4.45×1013s-1;第二失重阶段符合相边界动力学反应机制,模型函数g(a)=1-(1-a)0.45,平均活化能E=218.42 kJ/mol,指前因子A=1.07×108s-1。

The main cause of the spontaneous combustion of oil storage tank containing sulfur is that the corrupt products of tank has some oxidation tendency, and they can induce the oil spontaneous combustion when they are self-igniting. The one of corrupt products of tank, the sulfurized product of Fe （OH） 3, was simulated by the sulfuration equipment. Then the ther- mal analysis experiment was done. And the kinetic mechanisms of the corrupt products of Fe（OH） 3 were studied by using the model-free method and master plots. The results show that the thermalgravimetric （TG） plot of the sulfurized product of Fe （OH） 3 includes two stages of mass loss. The first oxidative reaction is up to the nucleation and nucleus growth mechanism and the kinetic model function is g（a） = [-In（ 1-a） ] 0. 6731 , the activated energy is 124.25 kJ/mol and the pre-exponential factor is equal to 4.45×10^13s^-1. The second oxidative reaction accords with the phase boundary reaction mechanism and the kinetic model function is g（a） = 1- （1-a ）0.45, the activated energy is 218.42 k J/tool and the pre-exponential factor is equal to ×10^8s^-1