一种新型煤基沥青的炭化性能研究

A Study on Carbonization of a Novel Coal-derived Pitch

采用压力反应釜探讨了一种新型煤基沥青的炭化性能。结果发现,在试验的所有炭化条件下该原料均能够形成各向异性焦,说明融并性能良好。在炭化温度450～470℃,生焦各向异性组织的方向性随着温度的提高而改善,但生焦的形貌有所变差;在过高的炭化温度500℃下,生焦的显微结构和形貌均变差;在炭化压力0.3～0.7MPa,随着压力下降各向异性组织的方向性有所改善而单位变细,生焦的形貌改变不明显。选取适中的炭化温度450℃,更高的炭化压力1.3MPa,通过控制炭化体系的温度差和炭化后期适当减压增强气体逸出的剪切作用,制备出了显微组织和形貌得到明显改善的生焦。可见,适中的反应速率、较低的体系黏度和有效的气体逸出对于中间相的定向排列十分重要。

carbonization of a novel coal-derived pitch was studied on a pressurized tubular reactor. It was found that the pitch could carbonize to anisotropic semicoke under all those testing conditions showing an good ability to coalescence. Effects of soaking temperature and pressure of carbonization on macroscopic appearance and microscopic texture of needle coke were studied. It was found that a moderate temperature range of 450-470℃ was helpful to the orientation of fluid mesophase and the optical texture of needle coke grcv, better wilh tempcrature increase while its＇ macroscopic appearance seemed to get worse, but under a higher temperature of 500℃, macroscopic appearance and optical texture of needle coke both turned worse significantly. In addition, with pressure decline in a moderate range of 0.5～0.7 MPa. the uniaxial orientation of fluid mesophase were obviously improved while its＇ appearance improved little. Under the soaking temperature and pressure of 450℃ and 1.3 MPa respectively, by taking measures of creating temperature gradient within carbonization system, depressur/zation and vacuum-pumping before the stage of solidification, both the appearance and optical texture of semicoke were improved greatly, which proved that moderate carbonization rate, lower viscosity and effectivc gases evolution were very crucial to the coalescence and orientation of fluid bulk mesophase.