Porphyrins in Heavy Petroleums: A Review
Porphyrins in Heavy Petroleums: A Review
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重石油中的卟啉：综述
DOI：
10.1007/430_2015_189
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发表时间：
2015
影响因子：
--
通讯作者：
Shi Quan
中科院分区：
文献类型：
--
作者：
Zhao Xu;Xu Chunming;Shi Quan
钒和镍是化石燃料矿床有机部分中含量最多、也最麻烦的金属化合物。这些金属化合物可能在精炼过程中造成重大的有害影响，导致用于除硫和除氮的催化剂失活。因此，在催化加氢和裂化前脱除石油馏分中的钒和镍是非常理想的。钒镍配合物一般分为卟啉类和非卟啉类。自从卟啉类化合物在原油和页岩中被发现以来，对它们的分离和鉴定一直是研究的重点。虽然有人提出非卟啉类化合物可能含有非典型卟啉或伪芳香族四齿化合物，但在原油中尚未发现非卟啉类化合物。紫外-可见（UV-vis）光谱和质谱是常用的分析技术，用于鉴定和定量卟啉。由于卟啉对紫外-可见辐射的高强度和高灵敏度的电子吸收，约有一半的钒和镍卟啉可以通过其特征紫外-可见光谱进行识别和定量。其余的钒和镍化合物，即非卟啉，是通过缺乏明显的紫外-可见光谱带来定义的。然而，x射线吸收精细结构（EXAFS）光谱和x射线吸收近边结构（XANES）光谱结果表明，这些非卟啉化合物确实仍以卟啉结构结合，尽管这些金属化合物没有表现出特有的紫外可见吸收。此外，最近的质谱分析结果表明，大多数钒镍化合物以卟啉的形式存在，包括烷基卟啉、含硫卟啉、含氮卟啉和含氧卟啉。含有O、S和N原子的卟啉与沥青质的结合要比极性较低的组分强。在紫外可见光谱中，与其他组分形成配合物会使Soret吸收发生偏移和衰减。卟啉通常被认为通过π -π相互作用与芳香族沥青质组分螯合或非共价结合。因此，部分钒和镍化合物在约400 nm处的Soret波段有很强的光吸收，而其余的则没有，可能是由于形成配合物或由于卟啉环的化学修饰。它们的化学环境对替代分离方法的影响是重要的。本文综述了目前对重质石油中钒和镍化合物形态的认识，并对分离和脱金属的方法进行了评价。分离钒镍化合物需要有效的分离和超高质量分辨率。傅里叶变换离子回旋共振质谱（FT-ICR MS）具有最高的可用宽带质量分辨率、质量分辨率和质量精度，被证明是定性分析石油馏分中钒和镍化合物的重要方法。
Vanadium and nickel are the most abundant and troublesome metal compounds present in the organic portions of fossil fuel deposits. These metal compounds may cause significant detrimental impact during refining processes, leading to the deactivation of catalysts used for sulfur and nitrogen removal. Therefore, it is highly desirable to remove vanadium and nickel from petroleum fractions before catalytic hydrogenation and cracking. Vanadium and nickel complexes generally have been classified into porphyrins and non-porphyrins. Studies of the porphyrins have focused extensively on their isolation and identification since their discovery in crude oils and shales. Although it was proposed that non-porphyrins will contain atypical porphyrin or pseudo aromatic tetradentate systems, no non-porphyrin molecules have been identified in crude oil. Ultraviolet–visible (UV–vis) spectroscopy and mass spectrometry are the common analytical techniques used to identify and quantify porphyrins. Due to the high intensity and sensitivity of electronic absorption of UV–vis radiation by porphyrins, approximately half of the vanadium and nickel porphyrins can be identified and quantified by their characteristic UV–vis spectra. The remaining vanadium and nickel compounds, the non-porphyrins, are defined by an absence of distinct UV–vis spectroscopic bands. However, the results of X-ray absorption fine structure (EXAFS) spectroscopy and X-ray absorption near-edge structure (XANES) spectroscopy indicated that these non-porphyrins are indeed still bound in a porphyrinic structure, although these metal compounds do not exhibit the characteristic UV–visible absorption. In addition, the recent results of mass spectrometry showed that majority of vanadium and nickel compounds existed in the form of porphyrins, including alkyl porphyrins, sulfur-containing porphyrins, nitrogen-containing porphyrins, and oxygen-containing porphyrins. The porphyrins with O, S, and N atoms should associate more strongly with the asphaltenes than the less polar components. Formation of complexes with other components would shift and attenuate the Soret absorption in UV–visible spectroscopy. The porphyrins are generally believed to chelate or non-covalently associate with aromatic asphaltene components by π–π interactions. Therefore, a portion of the vanadium and nickel compounds give strong optical absorption in the Soret band at ca. 400 nm, and the remainder do not, likely due to formation of complexes or due to chemical modification of the porphyrin ring. The implications of their chemical environments for alternative separation methods are important. In this review article, the current understanding of the forms of vanadium and nickel compounds in heavy petroleum is critically discussed and the methods of separation and demetallization evaluated. Effective separation and ultrahigh mass resolution are needed to resolve these vanadium and nickel compounds. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), which has the highest available broadband mass resolution, mass resolving power, and mass accuracy, is shown to be a significant method for the qualitative analysis of vanadium and nickel compounds in oil fractions.
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影响因子：
15
作者：
J. Quirke;G. Eglinton;J. Maxwell
通讯作者：
J. Quirke;G. Eglinton;J. Maxwell
影响因子：
4.2
作者：
Yasuhiro Shiraishi;†. A. Takayuki Hirai;I. Komasawa
通讯作者：
Yasuhiro Shiraishi;†. A. Takayuki Hirai;I. Komasawa
影响因子：
--
作者：
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通讯作者：
J. Sugihara;R. Bean
影响因子：
7.4
作者：
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通讯作者：
R. Fish;J. J. Komlenic-J.
影响因子：
3.9
作者：
J. Quirke;G. Eglinton;S. Palmer;E. W. Baker
通讯作者：
J. Quirke;G. Eglinton;S. Palmer;E. W. Baker