• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.255-257
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• 2014

The installation of light oil facilities or delayed cokers seems to be inevitable in the oil refinery industry due to the heavy crude oil reserves and the increased use of light fuels as petroleum products. Petroleum coke is a byproduct of oil refineries and it has higher fixed carbon content, higher calorific value, and lower ash content than coal. However, its sulfur content and heavy metal content are higher than coal. In spite of disadvantages, petroleum coke might be one of promising resources due to gasification processes. The gasification of petroleum coke can improve economic value of oil refinery industries by handling cheap, toxic wastes in an environment-friendly way. In this study, $CO_2$ gasification reaction kinetics of petroleum coke, various coals and mixing coal with petroleum coke have investigated and been compared by using TGA. The kinetics of $CO_2$ gasification has been performed with petroleum coke, 3 kinds of bituminous coal [BENGALLA, White Haven, TALDINSKY], and 3 kinds of sub-bituminous coal [KPU, LG, MSJ] at various temperature[$1100-1400^{\circ}C$].

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.487-490
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• 2008

Temperature programmed oxidation (TPO) is used to characterize coke species deposited on commercial nickel catalyst, C11-PR during propane pre-reforming. Propane pre-reforming performed under various condition, S/C from 1.5 to 2.5 and temperature from $350^{\circ}C$ to $450^{\circ}C$. There are three kinds of coke species detected by TPO: (i) reactive coke, (ii) coke deposited on metal site and (iii) coke deposited on acid support. Coke deposited on metal and support are minimized although reactive coke is generated at temperature of $400^{\circ}C$ and S/C of 2.0. Reactive coke is expected to remove easily below temperature of $200^{\circ}C$. Therefore, optimized pre-reforming condition for propane is $400^{\circ}C$ and S/C of 2.0.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.493-495
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• 2005

This paper proposes a swarm-based fuzzy system modeling technique for coke oven combustion control diagnosis. The coke plant produces coke for the blast furnace plant in steel making process by charging coal into oven and supplying gas to carbonize it. A conventional mathematical model for coke oven combustion control has been used to control the amount of gas input, but it does not work well because of highly nonlinear feature of coke plant. To solve this problem, swarm-based fuzzy system modeling technique is suggested to construct a diagnosis model of coke oven combustion control. Based on the measured input-output data pairs, the fuzzy rules are generated and the parameters are tuned by the PSO(Particle Swarm Optimizer) to increase the accuracy of the fuzzy system is operated. This system computes the proper amount of gas input taking the operation conditions of coke oven into account, and compares the computed result with the supplied gas input.

• Clean Technology
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• v.22 no.2
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• pp.82-88
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• 2016

The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1484-1487
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• 1996

An Automatic coking control system was developed to achieved substantial energy and labor savings through the stabilization and optimization of coke oven operation. With the aim of saving energy and labor, the coke department has been advanced automation and systematization. A typical examples of automation is Center Position Control System(CPCS) for coke oven. This system is proved effective in improvement of center position accuracy.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.97-103
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• 1994

The influence of ground petroleum coke, preheat-treated at temperatures ranged of 150~35$0^{\circ}C$, was studied. It has been found that the coke powder preheat-treated at the temperature of 175$^{\circ}C$ has been spherical-shaped in grinding and have showed the highest strength and density in sintering. The coke powder was also the best for the binding force and the (H/C) values showed 0.45 at the above temperature.

• Journal of the Korean Ceramic Society
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• v.29 no.10
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• pp.773-778
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• 1992

The effect of temperature on the structural changes of petroleum raw coke during calcination was studied and then the properties of carbon solids prepared from those calcined coke using binder were examined. The notable structural change of raw coke was observed in the range from 800$^{\circ}C$ to 900$^{\circ}C$ from the results of volatile matter, porosity, X-ray diffraction and scanning electron microscopy. The bending strength, density of the carbon solid carbonized at 1400$^{\circ}C$ was 400 kg/$\textrm{cm}^2$ and 1.40g/㎤, respectively.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.196-208
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• 2018

The effect of channel-system of zeolite on methanol-to-DME reaction was studied. Results revealed that channels size and topology affect catalyst lifetime, type and location of coke precursors. FER and MFI showed the best resistance towards coke deposition, whilst fast deactivation was observed on MOR. Although the higher concentration and strength of acid sites, FER structure formed a lower coke amount, preferably located within the pores, while coke cluster deposited on the external surface of MOR. Analysis of acid sites distribution and strength was performed during deactivation-regeneration process. Coke location assessment was also supported by molecular simulations.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.675-680
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• 2002

Cracking and bulging in welded and internally lined pressure vessels that work in thermal-mechanical cycling service have been well known problems in the petrochemical, power and nuclear industries. However, published literature and industry surveys show that similar problems have been occurring during the last 50 years. A better understanding of the causes of cracking and bulging causes is needed to improve the reliability of these pressure vessels. This study attempts to add information required for increasing the knowledge and fundamental understanding required. Typical examples of this problem are the coke drums in the delayed coking units refinery process. This case was selected for experimental work, field study and results comparison. Delayed coking units are among the refinery units that have higher economical yields. To shut down these units represents a high negative economical impact in refinery operations. Also, the maintenance costs associated with repairs are commonly very high. Cracking and bulging occurrences in the coke drums, most often at the weld areas, characterize the history of the operation of delayed coking units. To design and operate more robust coke drums with fewer problems, an improved metallurgical understanding of the cracking and bulging mechanisms is required. A methodology that is based field experience revision and metallurgical analyses for the screening of the most important variables, and subsequent finite element analyses to verify hypotheses and to rank the variables according to their impact on the coke drum lives has been developed. This indicated approach provides useful information for increasing coke drum reliability. The results of this work not only order the most important variables according to their impact in the life of the vessels, but also permit estimation of the life spans of coke drums. In conclusion, the current work shows that coke drums may fail as a combination of thermal fatigue and other degradation mechanisms such as: corrosion at high and low temperatures, detrimental metallurgical transformations and plastic deformation. It was also found that FEA is a very valuable tool for understanding cracking and bulging mechanisms in these services and for ranking the design, fabrication, operation and maintenance variables that affect coke drum reliability.

• Journal of Korea Foundry Society
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• v.9 no.3
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• pp.247-256
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• 1989

The gasification reaction rates by $CO_2$ in $CO/CO_2/N_2$ of various compositions in the temperature range of $900-1200^{\circ}C$ were measured for foundry coke and anthracite lump. The data for the rates was analyzed with Langmuir-Hinshelwood rate equations for the gasification of carbonaceous specimens. The values of the apparent activation energies of the reactions obtained from these data were ranged to be 47-99 and 73-128Kcal/mol respectively for foundry coke and for anthracite lump. The major contribution to decrease in tensile strength was shown to be attributable to the enlarging of the macropores in the coke and that of crack in the anthracite lump. Under the same experiment of the gasification of foundry coke, the rate of form coke was increasing as the addition of $Fe_2O_3$ increases.