煤直接液化残渣溶剂萃取组分的热解行为研究

利用热重技术和固定床热解/在线质谱检测技术研究了残渣萃取组分重质油(HS)、沥青烯(A)、前沥青烯(PA)和四氢呋喃不溶物(THFIS)的热解特性,并尝试探讨了各萃取组分的热解行为与加氢行为之间的关系。研究结果表明,残渣中各萃取组分的加氢转化能力与其热分解能力有关。四种组分在SHR加氢液化产生的正协同作用的原因,在于各萃取组分之间的相互作用导致了HS和A族组分中的某些低温挥发组分,在较低温度区间不挥发逸出,而在较高温度区间裂解,迎合了加氢液化对自由基碎片的需求。但PA的存在有利于缩聚反应的发生,可促进裂解产物的再聚合,从而对加氢液化产生不利影响。

Pyrolysis property of solvent extracts from a direct coal liquefaction residue

The pyrolysis behavior of solvent extracts (hexane solubles HS, asphaltenes A, preasphaltenes PA and THF insolubles THFIS) from a direct coal liquefaction residue (SHR) of Shenhua process were investigated by thermogravimetric analysis (TGA) and temperature programmed decomposition coupled with a mass spectrometry (TPD-MS) techniques. An attempt was made to understand the relationship between the cracking and hydrogenation activities. It shows that the hydrogenation activity of the extracts is related to their cracking ability. The synergetic effect among the fractions inhibits some of the components in HS and A fractions releasing through evaporation at 450℃ but cracking in 400℃~450℃ as free radicals. Then a positive effect can be observed. However, the presence of PA enhances the polymerization of the free radicals and then results in a negative effect on liquefaction of SHR.