含硫油品储罐腐蚀产物自燃性的研究

On spontaneous combustion characteristics of the iron sulfides in oil tanks containing sulfur

通过模拟储油罐中硫铁化物的生成方式,分析和研究了H2S气体在无氧条件下,与不同相对湿度的Fe2O3、Fe3O4和Fe(OH)3反应所生成的硫铁化物的自燃性。不同相对湿度的试样经6h硫化后,其自燃性明显不同。以Fe2O3试样为例,相对湿度为0的硫化产物氧化升温最高为256℃,平均升温速率为10.8℃/min;相对湿度为5%、10%和15%的硫化产物,氧化升温最高温度分别为474℃、408℃和388℃,平均升温速率分别为20.5℃/min、18.3℃/min和13.5℃/min。实验结果表明,不同相对湿度、不同物质的硫化产物,其自燃性有显著差异,样品的相对湿度对硫化产物的自燃性有重要影响。对各种干燥样品的硫化产物进行电镜分析发现,由不同物质硫化所生成的硫化产物结构不同,致使其自燃性有较大差异。硫铁化物氧化反应放热是引发油罐着火的主要因素。

This paper is aimed at introducing the authors＇ research of the spontaneous combustion characteristics of iron sulfides as a result of the reactions of hydrogen sulfide to the different degrees of humidity of the iron oxide black, iron oxide red and the iron hydroxide. The sulfuration reactions may last about six hours with the spontaneous combustion characteristics of resultants showing quite obvious discrepancy. As is shown in our experiments, the resultant product formed by the reaction of hydrogen sulfide with dry iron oxide red proves to be the residue left over by the air oxidization at the flow rate of 300 mL/min with its highest temperature of reaction up to 256 ℃. The average temperature-rising speed can be as quickly as 10.8 ℃/min. In addition, the resultants can be formulated as a result of hydrogen reacting to sulfide at 5%, 10% and 15% with the relative humidity of iron oxide red oxidized by the air at the flowing rate of 300 mL/ min. with its highest temperature of the oxidation reactions getting to 474 ℃, 408 ℃ and 388 ℃ respectively. The results show that it is possible to distinguish the spontaneous combustion of iron sulfides formed at different degrees of relative humidity from its combustion with other different materials. The experimental results of ours show that the relative humidity of the samples can play a very important role in the oxidation tendency of iron sulfides. When analyzing the iron sulfides formed from different dry iron oxides by TEM, we can find that the compounds of iron sulfides are various in their composition, which may lead to different spontaneous combustion features. However, our experiments prove that the exothermic oxidation of iron sulfides is the chief factor leading to the tank fire and explosion.