新疆低阶煤和重质油资源丰富,具有广阔的煤油共液化工业前景,但重质油自身流动性差,极大地限制了煤油共液化的发展。为认识重质油组成结构对油煤浆流变性能的影响,选取5种性质差异明显的重质油和2种工业循环溶剂油,探究其与上湾煤形成的油煤浆流变性能变化规律,在此基础上通过预加氢调控减压渣油的组成结构,分析重质油组成、结构与流变性能,获得重质油组成结构对油煤浆流变性能的影响规律。结果表明,重质油本身是牛顿流体,加入煤粉后转变为假塑性流体,呈现剪切稀化特征;重质油中胶质和沥青质组分含量越高,形成油煤浆的黏度越高,体系内部的触变结构越丰富,非牛顿流体特征越明显。减压渣油稠油预加氢后,形成油煤浆的黏度显著降低,其中,380℃下预加氢2h后制成的油煤浆黏度在135℃时降至451mPa·s,同时油煤浆的触变特性也明显减弱。预加氢促使减压渣油中的长链断裂为短链烃,胶质和沥青质组分转化为饱和分与芳香分,从而抑制胶团的生成,降低油煤浆黏度。其中,380℃下预加氢2h后胶质含量较未处理减少约21%,重均分子量降至1594Da,芳香环β位的H含量增加约20%。

Xinjiang,with abundant low-rank coal and heavy oil resources, holds significant potential for the coal-oil co-liquefaction industry. However, poor fluidity of heavy oil considerably hinders its development. To examine the impact of the compositional structure ofheavy oil on the rheological properties of coal-oil slurry, in this work, five types of heavy oils with distinct properties and two types of industrial circulating solvent oils were selected, and the variation in the rheological properties of the Shangwan coal-oil slurry was investigated. In addition, the compositional structure of the vacuum residue heavy oil was regulated via pre-hydrogenation. Based on the analysis ofthe composition, structure, and rheological properties of heavy oil, the influence of the compositional structure of heavy oil on the rheological properties of coal-oil slurry was revealed. The results indicate that heavy oil in its original state belongs to the Newtonian fluid. However, the addition of coal powder promotes the transform into a pseudoplastic fluid, displaying shear-thinning characteristics. High contentof resin and asphaltene components in heavy oil leads to high viscosity of the formed coal-oil slurry. In addition, the rich thixotropic structure within the system makes the non-Newtonian fluid characteristics more pronounced. The pre-hydrogenation of vacuum residue heavyoil significantly decreases the viscosity of the resultant coal-oil slurry. Notably, the viscosity of the coal-oil slurry by using pre-hydrogenation heavy oil at 380 ℃ for 2 h decreases to 451 mPa·s at 135 ℃ . Pre-hydrogenation facilitates the breakdown of long chains in vacuumresidue oil into short-chain hydrocarbons, the resin and asphaltene components in vacuum residue oil are transformed into saturated andaromatic components, thereby inhibiting the formation of micelles and reducing the viscosity of the coal-oil slurry. In particular, after prehydrogenation at 380 ℃ for 2 h, the resin content was decreased by about 21% compared to the untreated sample, the weight average molecular weight declines to 1 594 Da, and the H content at β position of the aromatic ring increases by about 20%.

0 引言

1 试验

   1.1 原料

   1.2 分析方法

   1.3 油煤浆的制备与性能测试

   1.4 重质油预加氢

   2.1 油样结构分析

   2.2 重质油对油煤浆流变特性的影响

   2.3 预加氢油组成结构对油煤浆流变性能的影响

3 结论