Characterization of Asphaltenes and Petroleum Using Benzenepolycarboxylic Acids (BPCAs) and Compound-Specific Stable Carbon Isotopes
Characterization of Asphaltenes and Petroleum Using Benzenepolycarboxylic Acids (BPCAs) and Compound-Specific Stable Carbon Isotopes
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DOI：
10.1021/acs.energyfuels.1c02374
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发表时间：
2021-10-19
期刊：
影响因子：
5.3
通讯作者：
Wagner, Sasha
中科院分区：
文献类型：
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作者：
Goranov, Aleksandar, I;Schaller, Morgan F.;Wagner, Sasha
沥青质是独特的分子，其丰度和结构控制着石油的物理化学性质。沥青质的结构外观（岛屿与群岛结构）取决于样品类型和石油来源，但区分这两种结构在分析上仍然具有挑战性。在这里，我们提出应用苯多羧酸（BPCA）分子标记方法来表征沥青质的稠合芳香核（ConAC）。这种热化学分解技术将 ConAC 部分转化为苯六甲酸 (B6CA) 和苯五甲酸 (BSCA)，通过色谱法对这些酸进行定量，并用于估计石油样品中 ConAC 的含量。使用 BPCA 标记的稳定碳同位素 (delta C-13) 进行序贯化合物特异性同位素分析 (CSIA) 可以提供与碳源和加工相关的额外表征维度。我们分析了重玛雅酸原油和轻马林平台 (MPCO) 原油及其各自的沥青质馏分。定量 BPCA 分析表明，相对于 MPCO 沥青质，玛雅酸性沥青质含有更高数量的较大 ConAC。各个 BPCA 标记物的 CSIA 显示，玛雅酸性沥青质相对于 MPCO 沥青质而言 C-13 贫乏，尽管样品类型之间的大量有机物 (δ C-13 值相似)。总之，定量和 CSIA BPCA 分析的结果表明，玛雅沥青质的岛屿主导结构和 MPCO 沥青质的群岛主导结构。因此，BPCA 量化和 BPCA 特定的 δ C-13 分析可能是一种表征成岩样品以及区分沥青质中稠合芳烃核心结构的有用方法。本文谨向 Alan G. Marshall 博士致敬，感谢他对分析化学和环境科学的科学发展做出的众多贡献，特别是傅里叶变换离子回旋共振质谱 (FT-ICR-MS) 技术的共同发明以及他在复杂基质（例如沥青质和石油）解卷积方面的工作。
Asphaltenes are unique molecules whose abundance and structure control physicochemical properties of petroleum. The structural appearance of asphaltenes (island versus archipelago architecture) is dependent upon the sample type and petroleum source, but distinguishing between the two architectures remains analytically challenging. Here, we present the application of the benzenepolycarboxylic acid (BPCA) molecular marker method to characterize the condensed aromatic core (ConAC) of asphaltenes. This thermochemolytic technique converts ConAC moieties to benzenehexacarboxylic (B6CA) and benzenepentacarboxylic (BSCA) acids, which are quantified chromatographically and used to estimate the quantity of ConAC in petrogenic samples. Sequential compound-specific isotope analysis (CSIA) with stable carbon isotopes (delta C-13) of BPCA markers can provide an additional dimension of characterization relative to carbon source and processing. We analyzed the heavy Maya sour and light Marlin platform (MPCO) crude oils and their respective asphaltene fractions. Quantitative BPCA analysis revealed that Maya sour asphaltenes contained higher quantities of larger ConAC relative to MPCO asphaltenes. CSIA of individual BPCA markers showed that Maya sour asphaltenes are C-13-depleted relative to MPCO asphaltenes, even though bulk organic (delta C-13 values were similar among sample types. Taken together, the results of quantitative and CSIA BPCA analyses suggest island-dominant architecture for Maya asphaltenes and archipelago-dominant architecture for MPCO asphaltenes. Therefore, BPCA quantification and BPCA-specific delta C-13 analysis may be a useful approach characterizing petrogenic samples as well as differentiating between structural architectures of condensed aromatic cores in asphaltenes. This article is in tribute to Dr. Alan G. Marshall for his numerous contributions to the scientific developments in analytical chemistry and environmental science, specifically the co-invention of the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) technique and his work toward the deconvolution of complex matrices, such as asphaltenes and petroleum.