• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.5
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• pp.449-458
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• 2007

In this paper, we reconstructed the cross-sectional images of two phantoms simulating a petrochemical process from gamma radiation measurements. Three different weight functions for EM image reconstruction algorithm were built and compared with histograms representing the variance of the homogeneity of the phantom material, The radiation source, $^{137}Cs$, collimated by a lead with 5 mm diameter aperture and the measurement was made with a lead shielded 1inch NaI detector. As a result, the method taking into account the beam area in each pixel for a weight function showed the best resolution among the three methods.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.158-168
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• 2007

The cement industry is one of the energy intensive industries such as petrochemical and steel industry. The energy efficiency of cement industry is high comparing to oversea's cement industries due to the enforcement of energy conservation policies. The purpose of this study is estimate emission factors for greenhouse gas ($CO_{2}$) in cement industry. The results of field study, quicklime contained quantity of five factories were $0.64{\sim}0.65$. Measurement emission (15,382 ton/day) is 40% higher than process emission (8,929 ton/day) on the IPCC Guidelines (1996). Add to combustion emission on the lines of IPCC Guidelines (1996) is similar to the emission of this study. The emission factor of greenhouse gas ($CO_{2}$) were as follows the emission factor between $9.01E-01{\sim}2.15E-01\;ton/ton$ for $CO_{2}$. The result of this study is higher than emission factor of IPCC (0.51) but it is similar to U.S. EPA's (0.952).

• 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.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.511-515
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• 2007

The yield of oil was rapidly increased at $440^{\circ}C$ compared to $400^{\circ}C$ and $420^{\circ}C$ when the isothermal pyrolysis of waste ship lubricating oil was carried out in tubular type reactor, and pyrolysis was almost finished within 30 min. The yield of gas was decreased depending on the reaction temperature in which that of solid was not much changed. Pyrolysis experiments of waste ship lubricating oil were carried out with used ZSM-5 produced from a petrochemical process. The yield of gas was highly increased in the case of used ZSM-5 and fresh ZSM-5 compared to the case without catalyst. The produced oil and gas were almost constant for fresh ZSM-5 and used ZSM-5 at the same reaction temperature. In the reaction temperature $400{\sim}440^{\circ}C$, the selectivity of $C_5-C_{11}$ was two times higher with fresh ZSM-5 and used ZSM-5 than the case without catalyst.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.55-60
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• 2012

The energy conservation and exergy loss of a fully thermally coupled distillation commercialized as the divided wall column are compared with those of a conventional two-column system for ternary separation. The used example for the comparison is the benzene-toluene-m-xylene separation process widely used in a petrochemical plant. The design procedure of the fully thermally coupled distillation column is explained, and the energy requirement is compared using the HYSYS. When the same numbers of trays are utilized, the fully thermally coupled distillation column uses 28.2% less energy and 10.4% more exergy loss. The increase of the exergy loss is due to the additional mixing from the bidirectional inter-linking and the temperature elevation in the reboiler from the increased pressure at the bottom of the main column.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.47-54
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• 1995

Water pollution, which is caused by surfactants, is increased by insolubility and excessive uses of detergents. The detergency properties of nine kinds of amphoteric surfactants derived from imidazoline were investigated and compared with sodium lauryl sulfats(SLS) of petrochemical surfactant by using detergent formulations. Several physico-chemical properties were measured to investigate the effective factors on detergency. From the comparision of these compounds with SLS, it was found that 1-(2-hydroxyethyl)-1- (3-sulfonatedpropyl)-2-undecyl-2-imidazolinum [IV] has the most outstnading characteristics of detergency and various fundamental properties. Therefore, this result is expected to do its environmental stability as a nonpolluting detergent. Detergency process of surfactants were discussed in relation to physico-chemical treatments. Performance improvement on detergency is made work of adhesion to soil as small as possible. Therefore these results show that contamination is easily removed and industrial applications may be respected.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.867-873
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• 1993

Influences of crystallization time and $H_2O/Al_2O_3$ ratio of the reaction mixtures on the synthesis of AlPO$_4$-5 molecular sieve have been studied by X-ray powder diffraction, nitrogen adsorption, scanning electron microscope (SEM), and solid state $^{27}$Al magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The degree of crystallinity of AlPO$_4$-5 follows a sigmoid pattem as crystallization time increases. The induction period is shorter than 1 h when the crystallization process is carried out at 150$^{\circ}$C. The conversion of reactants to product, AlPO$_4$-5, can be clearly observed, and all of the determined physical properties change abruptly after about 2 h. It is found that increase in $H_2O/Al_2O_3$ ratio of the reaction mixtures not only changes the crystal morphology from aggregates to hexagonal single crystals, but also results in the formation of longer AlPO$_4$-5 crystals.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.621-627
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• 2016

Low-priced hydrogen is required in petrochemical industry for producing low-sulfur oil, and upgrading low-grade crude oil since environmental regulations have been reinforced. Steel industry can produce hydrogen from by-product gases such as Blast Furnace Gas (BFG), Coke Oven Gas (COG), and Linze Donawitz Gas (LDG) with water gas shift (WGS) reaction by catalysis. In this study, we optimized conditions for WGS reaction with commercial catalysts by BFG and LDG. In particular, the influence on activity of gas-hourly-space-velocity, and $H_2O/CO$ ratios at different temperatures were investigated. As a result, 99.9%, and 97% CO conversion were showed with BFG, and LDG respectively under $350^{\circ}C$ High Temperature Shift (HTS), $200^{\circ}C$ Low Temperature Shift (LTS), 3.0 of $H_2O/CO$, and $1500h^{-1}$ of GHSV. Furthermore, 99.9% CO conversion lasted for 250 hours with BFG as feed gas.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.2
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• pp.127-134
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• 2017

For product or process design and development, it is common to optimize multiple responses (characteristics) based on experimental data. To determine optimal conditions, we need to design the experiment, estimate a proper model for each response, and optimize the multiple responses simultaneously. There are several techniques and many research results on optimizing multiple responses simultaneously, when the experimental data are available. However, the experimental design issue for optimizing multiple responses has not been discussed yet. This paper proposes some idea on how to plan screening design when requirements for multiple performance characteristics are to be met in developing new products. A screening design procedure is developed for securing the requirements of multiple responses. Initial design factors are classified into three categories; specific, non-conflicting common, and conflicting common. After screening experiments, follow-up design region search method is suggested with respect to the most unsatisfied or important response, or overall desirability. A case study on a synthesis of melamine formaldehyde resin is presented to illustrate the procedure and to show the validity of the approach.

• Resources Recycling
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• v.23 no.3
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• pp.71-77
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• 2014

It is believed to have the international competitiveness of the domestic petrochemical in conjunction with the production of high value-added new product and variety of application by supercritical fluid process and the reaction of infusible/insoluble plastic wastes recycling. In this article, the patents and papers for the recycling of organic residues from the plastic wastes using supercritical fluids were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1993 to 2012 were investigated. The patents and journals were collected using key-words and filtered by the definition of the technology. The patents and journals were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper.