油页岩干酪根化学键浓度与能量密度研究

以抚顺、茂名油页岩干酪根13C NMR、XPS与元素分析数据为基础,构建了油页岩干酪根分子结构模型,同时以化学键为标准对抚顺、茂名干酪根结构模型进行了修改,构建的干酪根结构模型与实验化学键浓度匹配良好,从化学键角度验证了模型的准确性与合理性。以自建及文献中九个不同变质程度的油页岩干酪根结构模型为基础,研究了油页岩干酪根变质程度与各类化学键浓度及能量密度关系。结果表明,随油页岩干酪根变质程度的提高,芳香碳分别与芳香碳、脂肪碳、氢原子等原子形成的化学键浓度升高,脂肪碳与脂肪碳、氢原子等原子形成的化学键浓度下降,其中,芳香碳之间、脂肪碳与氢原子之间的化学键浓度变化最明显。组成油页岩干酪根势能的价电子能密度及非键能密度随干酪根变质程度的提高总体上呈现上升趋势,成为组成油页岩干酪根稳定的化学能。

Chemical bond concentration and energy density of oil shale kerogen

The molecular structures of Fushun and Maoming kerogen were constructed based on the characterization techniques such as solid-state ¹³C nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS) and ultimate analysis. Self-build kerogen models were modified on the basis of chemical bond concentration, chemical bonds concentration of experiment data and molecular structure match well, therefore constructed models have been proved to be accurate and reasonable from the perspective of chemical bonds. From the data of self-build and selected kerogen models, the relationship between metamorphic degree of oil shale kerogen with concentration of chemical bonds and energy density were studied. With the increase maturity of oil shale kerogen, the chemical bonds concentration between aromatic carbon and aromatic carbon, aliphatic carbon, hydrogen atom increase, the chemical bonds concentration between aliphatic carbon and aliphatic carbon, hydrogen atom decrease. Among them the chemical bonds concentration between the aromatic carbons, and that between aliphatic carbon and hydrogen atom change obviously. Valence electron energy and non-bond energy are two parts that make up total energy, being the steady chemical energy of oil shale kerogen and increase with increase of its metamorphic degree.