X射线衍射法研究石油焦碳化过程的微晶变化

MICROCRYSTALLITE STRUCTURAL CHANGES OF PETROLEUM COKE DURING THE COURSE OF CARBONIZATION ANALYZED BY X-RAY DIFFRACTION

采用X射线衍射技术考察了石油焦碳化过程中的微晶结构变化。结果表明,当碳化温度低于600℃时,石油焦的结构以无定形炭结构为主,呈现一种层状的石墨态。当温度处于600-800℃范围时,其层状结构发生变化,层间距加大,新的乱层结构开始形成,如在此阶段采用改性添加剂对其结构进行调变,可以最大程度地获得具有乱层结构的“炭素前驱体”。当碳化温度高于800℃以后,又形成了类石墨的微晶层状结构。建议采用改性的乱层结构石油焦作为原料以制备具有空气分离特性的炭分子筛。

X-ray diffraction was used to analyze the changes of petroleum coke microcrystallite during carbonization. The results showed that the structure of petroleum coke remained amorphous presenting mainly a structure of layered pseudo-graphite when the carbonization temperature was lower than 600°C. Within the temperature range of 600-800°C, the layer structure changed, forming a new disordered structure, the coke precursor with disordered structure reached the greatest extent when improvers were used at this stage. As the temperature rose higher than 800°C, the new amorphous layered pseudo-graphite structure was again formed. It is suggested to use modified petroleum coke of disordered structure as the raw material to make carbon molecular sieves characterized of air separation capability.