Characterization and Structural Classification of Heteroatom Components of Vacuum-Residue-Derived Asphaltenes Using APPI (+) FT-ICR Mass Spectrometry
Characterization and Structural Classification of Heteroatom Components of Vacuum-Residue-Derived Asphaltenes Using APPI (+) FT-ICR Mass Spectrometry
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DOI：
10.1021/acs.energyfuels.1c01802
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发表时间：
2021-08-17
期刊：
影响因子：
5.3
通讯作者：
Lee, Ki Bong
中科院分区：
文献类型：
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作者：
Park, Jun Woo;Cho, Yunju;Lee, Ki Bong
傅里叶变换离子回旋共振质谱（FT-ICR MS）作为研究重油中沥青质结构的重大突破已被广泛应用。在这项研究中，使用 FT-ICR MS 分析了来自减压渣油的饱和烃、芳烃、树脂和沥青质 (SARA) 馏分，特别是对沥青质进行了详细检查。基本上，检查了 SARA 分数的质荷比谱、双键当量 (DBE) 分布和杂原子类别。之后，我们深入研究了具有非常高芳香性的沥青质，并根据杂原子类别对沥青质进行了分类，以了解其结构多样性。这种分类揭示了沥青质的DBE分布根据杂原子类别和杂原子的数量表现出不同的趋势，而这不能通过整个沥青质的DBE分布来识别。根据DBE的相对丰度峰和碳数分布，将DBE和碳数的组成空间分为不同杂原子类别的四组。各组对应的沥青质结构类型为马氏体组分（DBE 5-15，碳数20-60）、群岛型沥青质（DBE 10-25，碳数25-70）、岛型沥青质（DBE 15-35，碳数25-60）和较大岛型沥青质（DBE 35-50，碳数） 40-75），它们具有高度芳香性并且独立于正常的岛型沥青质。分类结果预计将用于开发沥青质的结构模型。
Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been widely used as a major breakthrough to investigate the structure of asphaltenes in heavy oils. In this study, saturates, aromatics, resins, and asphaltenes (SARA) fractions derived from vacuum residue were analyzed using FT-ICR MS, and, particularly, the asphaltenes were examined in detail. Basically, the mass-to-charge ratio spectra, double bond equivalents (DBE) distribution, and heteroatom classes of SARA fractions were checked. After that, we delved into the asphaltenes with very high aromaticity and classified the asphaltenes according to heteroatom classes to understand their structural diversity. This classification disclosed that the DBE distribution of asphaltenes exhibited different trends, depending on heteroatom classes and the number of heteroatoms, which could not be identified by DBE distribution of whole asphaltenes. Based on the relative abundance peaks of the DBE and carbon number distribution, the compositional space of DBE and carbon number was separated into four groups in various heteroatom classes. The structure types of asphaltenes corresponding to each group are maltene-like components (DBE 5-15, carbon number 20-60), archipelago-type asphaltenes (DBE 10-25, carbon number 25-70), island-type asphaltenes (DBE 15-35, carbon number 25-60), and larger island-type asphaltenes (DBE 35-50, carbon number 40-75), which are highly aromatic and independent of the normal island-type asphaltenes. The classification results are expected to be applied to develop a structural model of asphaltenes.