Structure and millisecond pyrolysis behavior of heavy oil and its eight group-fractions on solid base catalyst

Zhang, Jinhong; Niwamanya, Noah; Gao, Chunxiao; Sekyere, Daniel Takyi; Barigye, Andrew; Tian, Yuanyu

doi:10.1016/j.fuel.2022.123483

Cited by 14 publications

(3 citation statements)

References 31 publications

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“…They can also be classified as four and eight SARA fraction methodologies [28]. The SARA composition data can be used for evaluating relations between different SARA fractions [29], assessing the quality of petroleum [30], judging oil fouling potential [10], estimating vacuum residue properties [31], and understanding the chemical transformations taking place in vacuum residue upgrading processes [32,33]. Different approaches have been reported to predict the SARA composition of petroleum from other petroleum characteristics [34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Study of Bulk Properties Relation to SARA Composition Data of Various Vacuum Residues Employing Intercriteria Analysis

et al. 2022

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Twenty-two straight run vacuum residues extracted from extra light, light, medium, heavy, and extra heavy crude oils and nine different hydrocracked vacuum residues were characterized for their bulk properties and SARA composition using four and eight fractions (SAR-ADTM) methods. Intercriteria analysis was employed to determine the statistically meaningful relations between the SARA composition data and the bulk properties. The determined strong relations were modeled using the computer algebra system Maple and NLPSolve with the Modified Newton Iterative Method. It was found that the SAR-ADTM saturates, and the sum of the contents of saturates and ARO-1 can be predicted from vacuum residue density, while the SAR-ADTM asphaltene fraction content, and the sum of asphaltenes, and resins contents correlate with the softening point of the straight run vacuum residues. The softening point of hydrocracked vacuum residues was found to strongly negatively correlates with SAR-ADTM Aro-1 fraction, and strongly positively correlates with SAR-ADTM Aro-3 fraction. While in the straight run vacuum residues, the softening point is controlled by the content of SAR-ADTM asphaltene fraction in the H-Oil hydrocracked vacuum residues, the softening point is controlled by the content of SAR-ADTM Aro-3 fraction content. During high severity H-Oil operation, resulting in higher conversion, hydrocracked vacuum residue with higher SAR-ADTM Aro-3 fraction content is obtained, which makes it harder and more brittle.

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Section: Introductionmentioning

confidence: 99%

Study of Bulk Properties Relation to SARA Composition Data of Various Vacuum Residues Employing Intercriteria Analysis

et al. 2022

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“…The average molecular structure parameters of asphaltenes were calculated according to the improved Brown-Ladner (B-L) method (Table S2, Supporting Information). , Theoretically, asphaltenes by nature are a mixture of diverse compounds and the molecular structure of asphaltenes should contain all the components. However, the average molecular structure parameters of asphaltenes were generated on the basis of the average information on asphaltenes in crude oils .…”

Section: Methodsmentioning

confidence: 99%

Effect of Temperature on Asphaltene Precipitation in Crude Oils from Xinjiang Oilfield

Tian

Wang

et al. 2022

ACS Omega

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During the production of crude oil, asphaltenes are prone to precipitate due to the changes of external conditions (temperature, pressure, etc.). Therefore, a series of research studies were designed to investigate the effect of temperature on asphaltene precipitation for two Xinjiang crude oils (S1, S2) so as to reveal the mechanism of asphaltene dissolution. First, the changes of asphaltene precipitation were intuitively observed by using a microscope. The results demonstrated that the asphaltene solubility increased with the increase of temperature and the dispersion rate of asphaltene particles increased with the decrease of particle size. Second, the variation of asphaltene precipitation with temperature was quantified by a gravimetric method. The results suggested that the different asphaltenes showed different sensitivity to temperature within the temperature range 25–120 °C. Third, a hypothesis was proposed to explain these results and proved that the asphaltene aggregate structure was an important factor for asphaltene stability. The crystallite parameters of asphaltenes were obtained by X-ray diffraction (XRD) to describe the structural characteristics. The results revealed that the layer distance between aromatic sheets (d m ) of asphaltenes derived from S1 oil and S2 oil were 0.378 and 0.408 nm, respectively, which implied that the asphaltene aggregates derived from S2 oil were looser than those of S1 oil. Therefore, high temperature could facilitate the penetration of resins into asphaltene aggregates and ultimately improve the dispersion of asphaltenes. Finally, molecular dynamics (MD) simulation was used to verify the conclusions. Based on the molecular dynamics method, asphaltene aggregate models were developed. The compactness and internal energy of each model were calculated. The results showed that the asphaltene dispersion capability was proportional to the porosity and internal energy.

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“…The commonly used structural characterization methods for these heavy products, such as elemental analysis, FTIR spectroscopy, GPC analysis, synchronous fluorescence spectra, and nuclear magnetic resonance, often obtain one-sided information. ,,, The integration of this information is the key to constructing the macromolecules of SDP. The calculation of structural parameters with the Brown–Ladner method can integrate the information obtained by these analysis methods to construct the macromolecules of heavy products. , For instance, Zhang et al calculated the average structural parameters by the modified Brown–Ladner method to understand the millisecond pyrolysis behavior of heavy oil over the solid base catalyst from the near-molecular level and the relationship between the structural composition and the solid base catalytic cracking behavior of heavy oil. Shao et al studied the structural characterization of asphaltene from the hydrotreatment of low-temperature coal tar under various pressures by the Brown–Ladner method and found that the naphthenic ring number remains almost unchanged, while the aromatic ring number reduced with pressure, demonstrating that the ring-opening rate of the naphthenic ring is slightly larger than the hydrogenating rate of the aromatic ring.…”

Section: Introductionmentioning

confidence: 99%

Construction of Macromolecules of Depolymerized Lignite

et al. 2023

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Preparing ash-less coal and further converting it into chemicals is an efficient and promising means for lignite utilization. This work performed depolymerization of lignite to prepare ash-less coal (SDP) and separated it into the hexane-soluble fraction (HS), toluene-soluble fraction (TS), and tetrahydrofuran-soluble fraction (THFS). The structure of SDP and those of subfractions were characterized by elemental analysis, gel permeation chromatography, Fourier transform infrared spectroscopy, and synchronous fluorescence spectroscopy. The results show that SDP is a mixture of aromatic derivatives containing alkyl substituents and oxygen-containing functional groups. The number of condensed aromatic rings, the amount of oxygen-containing functional groups, and the molecular weight gradually increase as HS < TS < THFS. SDP was further analyzed by 1H-NMR and 13C-NMR to calculate its structural parameters. The macromolecule of THFS contains 15.8 total ring systems with 9.2 aromatic rings and 6.6 naphthenic rings. On average, each THFS molecule contains 6.1 alcohol hydroxyl groups, 3.9 phenol hydroxyl groups, 1.4 carboxyl groups, and 1.0 inactive oxygen-containing functional groups. The dominant reactions occurred during depolymerization are the breakage of ether linkages. The average THFS molecule consists of 3.3 structural units with aromatic nuclei (2.8 rings on average) linked with methylene, naphthene, and so forth.

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Structure and millisecond pyrolysis behavior of heavy oil and its eight group-fractions on solid base catalyst

Cited by 14 publications

References 31 publications

Study of Bulk Properties Relation to SARA Composition Data of Various Vacuum Residues Employing Intercriteria Analysis

Study of Bulk Properties Relation to SARA Composition Data of Various Vacuum Residues Employing Intercriteria Analysis

Effect of Temperature on Asphaltene Precipitation in Crude Oils from Xinjiang Oilfield

Construction of Macromolecules of Depolymerized Lignite

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