柴油低温流动改进剂对柴油分子存在状态的影响

发布时间：2018-07-22 20:17

【摘要】：采用分子动力学方法,模拟不同柴油分子体系中分子存在状态随温度的变化,经对比发现正构烷烃分子构象随温度降低"从弯到直"的显著变化是其在低温下容易聚集、结晶的主要原因,正构烷烃分子保持弯曲构象,有利于改善正构烷烃体系的低温流动性能。在此基础上,模拟含低温流动改进剂(CFI)的正构烷烃体系中分子存在状态随温度的变化,结果表明,CFI分子可以通过分子间相互作用力为正构烷烃分子扭转角的旋转提供足够能量,使分子保持弯曲构象,从而减弱分子间的相互作用并降低分子堆积的有序性和致密性。分子链可向空间多个方向伸展,分子内含有多个弯曲程度较高的结构片段,且与正构烷烃分子间的相互作用较强的CFI分子能显著促进正构烷烃分子保持弯曲构象。
[Abstract]:The molecular dynamics method was used to simulate the variation of molecular states with temperature in different diesel molecular systems. It was found by comparison that the conformation of n-alkanes changed "from curved to straight" with the decrease of temperature, and that the molecular conformation of n-alkanes was easily aggregated at low temperature. The main reason of crystallization is that n-alkane molecules keep bending conformation, which is beneficial to improve the low-temperature fluidity of n-alkane system. On this basis, the molecular states of n-alkanes with low-temperature flow improver (CFI) are simulated. The results show that CFI molecules can provide sufficient energy for the rotation of torsion angle of n-alkanes by intermolecular interaction. The molecular bending conformation is maintained, which weakens the intermolecular interaction and reduces the order and density of molecular stacking. The molecular chain can be extended in many directions in space, and there are many structural fragments with higher bending degree in the molecule, and CFI molecules with strong interaction with n-alkanes can significantly promote the bending conformation of n-alkane molecules.
【作者单位】：中国石化石油化工科学研究院;
【基金】：中国石油化工股份有限公司合同项目(109032)
【分类号】：TE624.81

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