Correlations Between Properties of Various Feedstocks and Products of Visbreaktng

Brauch, R.; Fainberg, V. S.; Kalchouck, H.; Hetsroni, G.

doi:10.1080/08843759608947610

Cited by 20 publications

(21 citation statements)

References 5 publications

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“…However, the vacuum residual oil dilution has also shown to be a demanding job requiring achievement of reproducible homogenizing. The high dispersion in the data of the correlation between visbreaker feed viscosity and visbroken residue observed in the earlier studies [2,3] could be attributed to unequal distillation characteristics of the visbroken residue and also to the procedures used to measure viscosity of high viscous materials like the vacuum residual oils.…”

Section: Relation Between Visbreaker Feedstock Viscosity and Visbrokementioning

confidence: 90%

“…An earlier study has shown that visbroken residue viscosity can fluctuate even during processing of the same feed (vacuum residue) which illustrates the complexity of this subject [2]. Brauch et al investigating correlations between some characteristics (density, viscosity, asphaltene and sulfur contents, stability) of the vacuum residues and products of their visbreaking have shown a relatively high dispersion of the data resulting in low correlation coefficients of the developed correlations [3]. In order to further illustrate the complication of this matter data of viscosity of the unconverted residue obtained in the LNB VBU during processing of the crudes REBCO, and blends of REBCO with Basrah (Iraq crude), Kirkuk (Iraq crude), HICO, Varandey (Russian crude), Tomsk atmospheric residue (Russian AR), and RAYG atmospheric residue (Russian AR) are presented in Fig.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Dependence of visbroken residue viscosity and vacuum residue conversion in a commercial visbreaker unit on feedstock quality

Stratiev¹,

Nedelchev²,

Shishkova³

et al. 2015

Fuel Processing Technology

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Section: Relation Between Visbreaker Feedstock Viscosity and Visbrokementioning

confidence: 90%

Section: Introductionmentioning

confidence: 98%

Dependence of visbroken residue viscosity and vacuum residue conversion in a commercial visbreaker unit on feedstock quality

Stratiev¹,

Nedelchev²,

Shishkova³

et al. 2015

Fuel Processing Technology

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“…Important reactions that could potentially lead to the onset of coking, such as addition reactions within the vacuum residue boiling range, cannot be described. Although a mixture of boiling fractions and solubility classification is sometimes used as pseudo-compounds to mitigate this shortcoming, asphaltenes as a solubility class may not be a good predictor of the onset of coking …”

Section: Modeling Visbreaking At Low Temperaturesmentioning

confidence: 99%

“…Although a mixture of boiling fractions and solubility classification is sometimes used as pseudo-compounds to mitigate this shortcoming, asphaltenes as a solubility class may not be a good predictor of the onset of coking. 68 At lower temperatures, reactions that require high activation energy are unlikely to take place at a meaningful rate. The contribution of reactions with low activation energy increases relative to those with high activation energy as the temperature is decreased.…”

Section: Modeling Visbreaking At Low Temperaturesmentioning

confidence: 99%

Thermal Conversion Modeling of Visbreaking at Temperatures below 400 °C

Klerk

2020

Energy Fuels

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This paper is in honor of Michael (Mike) T. Klein, and his contributions to the modeling of thermal conversion are highlighted within the context of this study. The question that was posed is whether thermal conversion models developed for conventional visbreaking (430–490 °C) are adequate for the description of visbreaking at lower temperatures? This topic is relevant to partial upgrading of bitumen by visbreaking at temperatures of <400 °C. Insights from thermal conversion performed at 100–430 °C were employed to revisit the description of the free radical chemistry and how temperature affected the relative importance of thermal reactions. With a decreasing temperature, the increasing contribution of reactions, such as molecule-induced homolysis and the presence of “persistent” free radical species in the feed, results in a higher free radical concentration than is predicted by initiation through thermally induced homolytic bond dissociation. With a decreasing temperature, transfer reactions are also increasing in relative importance. This affects propagation and termination reactions. One of the important consequences of the increased contribution of transfer reactions at lower temperatures is that the apparent activation energy of cracking is reduced. The threshold temperature below which conventional visbreaking models no longer provide an adequate description of conversion is 380–400 °C. Drawing on the differences that must be captured to model low-temperature thermal conversion, it was shown that the development work by Mike Klein provided a solid basis for such modeling. Of particular importance is the ability to incorporate reactive intermediates that include radical isomers and to model transfer reactions. Quantitative structure–reactivity relationships captured the essence of the chemistry that must be reflected to model low-temperature thermal conversion.

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“…The reaction rate equations are differential equations like Eqs. (4)(5)(6)(7)(8) that are solved by using the Runge-Kutta method. Fig.…”

Section: Case 1: Prediction Of Yields Of Productsmentioning

confidence: 99%

The Study of Molecular Modeling for Heavy Oil Thermal Cracking

Liang

Zhang

2007

Chem Eng & Technol

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The tighter specifications for refining products have gradually led refineries to focus on the molecular modeling of petroleum processing. In this work, a systematic methodology is presented for the molecular modeling of heavy oil thermal cracking (HOTC). This research which is based on a microscopic understanding provides a basis to achieve better design, management, optimization, and control of HOTC. The molecular information of HOTC product streams is represented in the form of a MTHS (molecular type homologous series) matrix. From consideration of the complexity of structural isomers in heavy petroleum fractions, the heavy molecules in a homologous series are grouped to reduce the dimension of the MTHS matrix. Transformation correlations are developed to capture the molecular properties of each homologous series in the MTHS matrix and to interrelate the molecular composition and bulk properties of the product streams. The HOTC process model was built on the basis of the molecular representation provided by the MTHS matrix and the transformation correlations. Two case studies are illustrated for validation of the proposed model and methodology.

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Correlations Between Properties of Various Feedstocks and Products of Visbreaktng

Cited by 20 publications

References 5 publications

Dependence of visbroken residue viscosity and vacuum residue conversion in a commercial visbreaker unit on feedstock quality

Dependence of visbroken residue viscosity and vacuum residue conversion in a commercial visbreaker unit on feedstock quality

Thermal Conversion Modeling of Visbreaking at Temperatures below 400 °C

The Study of Molecular Modeling for Heavy Oil Thermal Cracking

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