Coking rates in a laboratory pyrolysis furnace: liquid petroleum feedstocks

Leftin, Harry P.; Newsome, David S.

doi:10.1021/ie00065a026

Cited by 7 publications

(7 citation statements)

References 6 publications

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“…CII is an empirical method for estimating the relative coking propensity of petroleum streams. 19 The CII is a function of specific gravity, sulfur content, and aromaticity, as expressed by the US Bureau of Mines Correlation Index (BMCI): BMCI = (48640/VABP) + 473.7SG − 456.8, where VABP is volume average boiling point, in Kelvin, and SG is specific gravity. The VABP was calculated from simulated distillation gas chromatography (SimDis-GC) data as the average of cut point temperatures for 10, 30, 50, 70, and 90% loss of petroleum feed.…”

Section: Resultsmentioning

confidence: 99%

“…To account for this, the coking inhibition index (CII) was determined. CII is an empirical method for estimating the relative coking propensity of petroleum streams . The CII is a function of specific gravity, sulfur content, and aromaticity, as expressed by the US Bureau of Mines Correlation Index (BMCI): BMCI = (48640/VABP) + 473.7SG – 456.8, where VABP is volume average boiling point, in Kelvin, and SG is specific gravity.…”

Section: Resultsmentioning

confidence: 99%

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Effect of Petroleum Feedstock and Reaction Conditions on the Structure of Coal-Petroleum Co-Cokes and Heat-Treated Products

2012

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Bituminous coal/petroleum co-cokes were produced by coking 4:1 blends of vacuum resid (VR)/coal and decant oil (DO)/coal at temperatures of 465 and 500 °C for reaction times of 12 and 18 h, under autogenous pressure in microautoclave reactors. Co-cokes were calcined at 1420 °C and graphitized at 3000 °C for 24 h. Optical microscopy, surface area measurements, X-ray diffraction, temperature-programmed oxidation, and Raman spectroscopy were used to characterize the products. Product yield distribution analysis suggested an increase in co-coke yield as reaction severity index increases, although the increase yield is small at higher index values. It was found that higher reaction temperature (500 °C) or shorter reaction time (12 h) leads to an increase in the amount of mosaic carbon at the expense of textural components necessary for the formation of anisotropic structure, namely, domains and flow domains in the co-coke texture. Characterization of graphitized co-cokes showed that the quality, as expressed by the degree of graphitization, crystallite dimensions, Raman disorder parameter, and oxidation reactivity temperature of the final product, is dependent on the nature of the precursor co-coke, with products obtained from co-cokes produced at 500 °C showing a higher structural disorder than the corresponding products produced at 465 °C. The products obtained from DO/coal blend also displayed better structural order than products derived from VR/coal.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effect of Petroleum Feedstock and Reaction Conditions on the Structure of Coal-Petroleum Co-Cokes and Heat-Treated Products

2012

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“…The catalytic activity decreases when the metal particle is covered with coke, at which point the coking mechanism changes from catalytic coking to pyrolytic coking, and the coking rate gradually decreases to a steady-state value. 1,2 The methods to reduce coke formation include pretreatment of feedstocks, alteration of the inner surface chemistry of the cracking tube, 3,4 and addition of coking inhibitors. 5,6 For example, the carbonÀsteam reaction can be accelerated by alkali metal elements.…”

Section: Introductionmentioning

confidence: 99%

“…In the initial stage of thermal cracking, the coking mechanism is mainly catalytic coking with a high rate, , and filamentous coke is the typical morphology of catalytic coke. , The active metal particle is at the top of filamentous coke. Moreover, amorphous carbon is always present during thermal cracking.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Potassium Acetate on Coke Growth during Light Naphtha Thermal Cracking

Wang

Luan

et al. 2011

Ind. Eng. Chem. Res.

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Potassium acetate was used as a coking inhibitor to reduce coking during light naphtha cracking on a Cr25Ni35 alloy specimen that had already been used for 8 years. The effects of the mass concentration of potassium acetate on the morphology and structure of coke were investigated by high-resolution scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results show that the oxide scale formed on the inner surface of the cracking tube after 8 years of service is mainly composed of (Fe, Ni, Cr) spinels and the needlelike intermetallic compound of Cr and Fe. Changes of the surface conditions accelerate catalytic coking. The amount of coke decreases with increasing mass concentration of potassium acetate in a 1-h cracking period. The amount of coke was found to decrease by about 60% when the mass concentration was 400 ppm. The diameters of filamentous coke were about 100, 60, 45, and 35 nm when the mass concentrations of potassium acetate were 0, 100, 200, and 400 ppm, respectively. However, the gasification reaction was found to have little effect on the length of catalytic coke. The gasification reaction catalyzed by potassium acetate removes the noncatalytic coke surrounding the filamentous coke, and filamentous cokes at different concentrations are carbon nanofibers with a solid structure. Coke is mainly composed of amorphous carbon.

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Production of olefin and aromatic hydrocarbons by pyrolysis of gas condensate

Kaddour

Sherbi

Busenna

et al. 2009

Chem Technol Fuels Oils

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In Algeria, gas condensates occupy second place after crude with respect to volume of recovery. They are exported to France, Belgium, countries of South America, and certain other countries, and are also used to produce the 85-180°C cut and diesel fuel. The 85-180°C cut is directed into a reformer for the production of high-octane reformate.Algerian gas condensates contain mixtures of paraffins and naphthenes, and also a small amount of aromatic hydrocarbons. Since these condensates have a paraffin-naphthene base, it is possible to use them as pyrolysis feedstock for the production of olefins and aromatic condensates [1, 2]. The olefin hydrocarbons serve as feedstock for the production of polymers, and the aromatic hydrocarbons as feedstock for pyrolysis -high-octane additives to premium-grade commercial gasolines At the present time, low-octane gasoline cuts are subjected to pyrolysis, as a result of which the volume of the 85-180°C cut -reformer feedstock, is reduced. The purpose of this paper is to investigate laws governing pyrolysis of the 36-279°C cut of gas condensate, and ascertain optimal conditions for the production of ethylene and propylene. Physico-chemical characteristics of this cut are presented below:

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Coking rates in a laboratory pyrolysis furnace: liquid petroleum feedstocks

Abstract: Ranzi, E.; Dente, M.; Pierucci, S.; Barendregt, S.: Cronin, P. Oil Gas Shah, Y. T.; Stuart, E. B.; Sheth, K. D. Ind. Eng. Chem. Process Des. Trimm, D. L. Catal. Reu.-Sci. Eng. 1977, 16(2), 155. Trimm, D. L.; Holmen, A,; Lindvag, 0. J . Chem. Technol. Biotech-265-325.

Cited by 7 publications

References 6 publications

Effect of Petroleum Feedstock and Reaction Conditions on the Structure of Coal-Petroleum Co-Cokes and Heat-Treated Products

Effect of Petroleum Feedstock and Reaction Conditions on the Structure of Coal-Petroleum Co-Cokes and Heat-Treated Products

Effect of Potassium Acetate on Coke Growth during Light Naphtha Thermal Cracking

Production of olefin and aromatic hydrocarbons by pyrolysis of gas condensate

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