Abstract

Hydroprocessing of low-temperature coal tar from Shanbei (SLCT) on Ni–Mo–W/γ–Al₂O₃ catalysts was carried out in an autoclave. The compositions and structures of asphaltenes obtained from hydrotreated products at temperatures of 350–410 °C have been characterized by elemental analysis, FTIR, ¹H NMR and fluorescence spectroscopy (FL). Results indicate that temperature has significant influence on the hydrogenation and cracking functions of catalyst. At temperature 370 °C or below, the asphaltene conversions increase obviously while molecular weights are not evidently reduced as temperatures go up. Moreover, compared with asphaltene in SLCT, the asphaltene from hydrotreated products contains higher H/C ratio. It can be speculated that the hydrogenation reaction becomes dominant at lower temperature. In addition, the asphaltenes hydrotreated at higher temperature always contain lower H/C ratio and lower molecular weight. The results may be attributed to some cracking reactions. As for the heteroatoms (S, N and O) in asphaltenes, their removal efficiency is not only affected by temperature, but also the forms located in molecular structure. In addition, as the temperature increased, both the average side chain length and the number of naphthenic rings show a slight decrease. However, the aromatic degree (f_A) increases and surprisingly the number of aromatic rings shows a slight increase. It indicates that higher reaction temperature is unfavorable to the hydrogenation of aromatic ring system.

中文翻译：

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Ni-Mo–W / γ–Al 2 O 3催化剂在不同反应温度下低温煤焦油加氢处理过程中沥青质组成和结构的研究

抽象的

从陕北（SLCT）在Ni-Mo系-W /γ-Al系低温煤焦油加氢_2种ö ₃催化剂在高压釜中进行。在350–410°C的温度下从加氢处理的产品中获得的沥青质的组成和结构已通过元素分析（FTIR，^1）进行了表征1 H NMR和荧光光谱法（FL）。结果表明温度对催化剂的加氢和裂化功能有重要影响。在370°C或更低的温度下，随着温度的升高，沥青质转化率明显增加，而分子量却没有明显降低。此外，与SLCT中的沥青质相比，加氢处理产品中的沥青质具有更高的H / C比。可以推测，氢化反应在较低温度下占主导地位。另外，在较高温度下加氢处理的沥青质总是具有较低的H / C比和较低的分子量。结果可能归因于一些裂化反应。至于沥青质中的杂原子（S，N和O），其去除效率不仅受温度的影响，而且还受分子结构形式的影响。另外，随着温度的升高，平均侧链长度和环烷烃环数均略有下降。但是，芳香度（f _A）增加，并且令人惊讶地，芳环的数量显示出轻微的增加。这表明较高的反应温度不利于芳环体系的氢化。