• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.127-132
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• 2009

This report examines the economic feasibility of a commercial 50,000 barrel per day direct coal liquefaction(DCL) facility to produce commercial-grade diesel and naphtha liquids from medium-sulfur bituminous coal. The scope of the study includes capital and operating cost estimates, sensitivity analysis and a comparative financial analysis. Based on plant capacity of 50,000BPD, employing Illinois #6 bituminous coal as feed coal the total capital cost appeared $3,994,858,000. Also, the internal rate of return of DCL appeared 6.60% on the base condition. In this case, coal price and sale price of products were the most influence factors. And DCL's payback period demanded a long time(12.3 years), because of high coal price at the present time. According to sensitivity analyses, the important factors on DCL processes were product sale price, feed coal price and the capital cost in order.

• Carbon letters
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• v.1 no.2
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• pp.69-75
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• 2000

Naphtha cracking bottom oil was reformed with heat treatment and then spun at $310^{\circ}C$. These pitch-based carbon fibers were carbonized at $1000^{\circ}C$ after oxidation at $280^{\circ}C$, for 90 min. These fibers were chemically activated with molar ratio of KOH/CF (1 : 1) at different temperatures ($250{\sim}900^{\circ}C$) for 1 hr. The process of activation was characterized with DTA, TGA, BET surface area and pore size distribution. The activation of fibers by KOH was performed by several process. One is the reduction process that carbon fiber was reacted with $K_2O$ produced from dehydration process above $400^{\circ}C$. The other is the process that $K_2CO_3$ was directly reacted with carbon fiber. At $800^{\circ}C$, the activation was performed by catalyzed mechanism that $K_2O$ was obtained from the reaction of metal potassium with $CO_2$, then was changed to $K_2CO_3$. At $870^{\circ}C$, the activation was also observed that activation mechanism was promoted by metal catalyst with $CO_2$ from decomposition of $K_2CO_3$. The specific surface area of prepared activated carbon fibers was dependent on the activation mechanism. The specific surface area was in the range of $1519{\sim}2000\;cm^3/g$ and was the largest prepared at $870^{\circ}C$. The pores developed were mostly micropores which was very narrow and uniform. The total pore volume was $0.58{\sim}0.77\;cm^3/g$.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.563-568
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• 2008

In petroleum refining industry, caustic (NaOH) solution is used to remove $H_2S$ from hydrocarbon streams in naphtha cracking process. Once $H_2S$ is absorbed in caustic solution, the solution becomes known as spent sulfidic caustic (SSC), which contains high concentrations of hydrogen sulfide and alkalinity. This study was focused on the evaluation of autotrophic denitrification by SSC in a hybrid Bardenpho process. SSC was injected to the anoxic (1) and anoxic (2) tank at different S/N ratio. In a previous lab-scale study, as we operated a modified Ludzack-Ettinger process, it was observed that the COD increment of effluent and nitrification failure happened because of non-biodegradable matters in SSC and high pH, respectively. Thus cilia media was packed at 2.4%(v/v) in all aerobic tanks and the pH of SSC was neutralized from 13.3 to 11.5 with addition of sulphuric acid ($H_2SO_4$). Consequently, these strategies were successful because no COD increment of effluent was observed and nitrification failure did not happen. The maximum TN removal efficiency was 77.5% when SSC was injected to both the anoxic (1) and anoxic (2) tanks. The mean TN concentration of effluent in this condition was 5.8 mg/L.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.863-867
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• 2008

Pitch based activated carbon fiber(ACF) was prepared from reformed naphtha cracking bottom oil(NCB oil) by melt spinning. The fibers obtained were stabilized, carbonized, and then steam activated. The ACF was sensitized with Pd-Sn catalytic nuclei via a single-step activation approach. This sensitized ACF was used as precursors for obtaining copper plated ACFs via electroless plating. ACFs uniformly decorated with metal particles were obtained with reduced copper plating in the reaction solution. Effects of the amount of copper on characteristics of ACF/Cu catalysts were investigated through BET surface area, X-ray diffraction, scanning emission microscopy, and ICP. The amount of copper increased with plating time, but the surface area as well as the pore volume decreased. NO conversion increased with reaction temperature. NO conversion decreased with increasing the amount of copper, which is seemed to be due to the reduction of surface area as well as the dispersion of copper.

• Magazine of the Korea Concrete Institute
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• v.6 no.4
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• pp.85-91
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• 1994

In the previous study, naphthalene and /or naphthol were sulfonated wlth sulfuric acid and they were condensated with formaldehyde. The condensates prepared are subjected to the flow and strength tests of cement rnortnr to examine the chemcal effects of cement adrnlxtures. As the results of flow test, the flow of cement mortar mxed wth naphthol condensates(TSC) and naphthol naphthalene cocondensates( NT5) was larger than those mxed with synthetic naphtha lene condensate (NSS). In the experiments of compressive strength after 28 days curing, the hardned cement mortar containing naphthalene naphthol condensates(N1'5) showed a higher compressive strength than those contairung naphthalene condensates(NSS) and naphthol condensates('I'SC). As a results, the synthetic naphthalene condensates(NT5, TSC 1, whlch used i n this study, are greatly expected as good superplasticizers for the concrete.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.421-421
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• 2010

적색과 녹색 유기발광소자 보다 청색 유기발광소자는 상대적으로 발광 효율이 낮고 색 순도가 낮으며 수명이 짧은 이유로 유기발광소자를 이용한 전색 디스플레이 패널 구현에 많은 어려움이 있다. 이 문제를 해결하기 위하여 청색 유기발광 소자의 발광 효율을 향상하기 위한 방법으로 기존의 제작되는 불순물이 첨가된 단일 발광 호스트층을 이용한 유기발광소자와는 다르게 불순물이 첨가된 혼합된 발광 호스트층으로 구성된 발광 기능층을 가진 유기발광소자의 전기적 성질과 광학적 성질에 대한 연구를 하였다. 본 연구에서는 1.3-Bis(carbazol-9-yl)benzene 인광 호스트 유기화합물과 5%의 3-Tert-butyl-9,10-di(naphtha-2-yl)anthracene 형광 호스트 유기화합물을 혼합된 발광 기능층으로 적용하고 8%의 bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl-l) iridiumIII 인광 불순물을 첨가한 청색 유기발광소자와 5%의 4,4'-Bis[4-(diphenylamino)styryl] biphenyl (BDAVBi) 형광 불순물을 첨가한 청색 유기발광소자를 제작하여 전기적 성질과 광학적 성질을 비교하였다. 형광 불순물인 BDAVBi를 첨가하여 제작된 청색 유기발광소자는 전류밀도 $20\;mA/cm^2$에서 5.78 cd/A의 발광 효율을 구현하였다. 대역폭이 큰 인광 호스트 물질에서 형성된 엑시톤이 효율적으로 대역폭이 상대적으로 작은 형광 호스트로의 에너지 전달이 일어나고 형광 호스트에서 형성된 엑시톤이 대역폭이 더 작은 형광 불순물로의 에너지 전달이 효율적으로 전달 됨을 알 수 있다. 인광 호스트에서 형성된 엑시톤이 중간 과정을 거치지 않고 바로 형광 불순물로의 에너지 전달이 형성되어 주입된 캐리어가 기존의 소자보다 에너지 전달 과정을 거쳐 다수의 엑시톤이 소멸하지 않고 발광에 기여하여 상대적으로 전류가 작게 흐르고 다량의 엑시톤이 외부로 추출되어 효율이 증가하였다. 전계 발광 스펙트럼 분석에서 메인 피크가 467 nm 영역에서 형성되지만 불순물에 의한 부 피크가 491 nm 영역에서 형성되어 시각계 곡선과 중첩되는 영역을 추가로 형성하여 효율이 증가하게 되는 것을 알 수 있었다. 그러므로 불순물이 첨가된 혼합된 호스트 발광층을 적용한 유기발광소자는 높은 발광 효율을 가지는 청색 유기발 광소자 디스플레이 패널 제작 가능성을 제공하고 있다.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.455-460
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• 2019

Hydrotreating catalysis refers to a various hydrogenation which saturate an unsaturated hydrocarbon, together with removing heteroatoms such as sulfur, nitrogen, oxygen, and trace metals from different petroleum streams in a refinery. Most refineries include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate process streams, and/or residue. Among them, hydrotreating catalysis for residue are the core of the process, because of its complexity. This article reviews recent progress in tackling the issues found in the upgrading residues by hydrotreating, focusing on the chemistry of hydrodemetallization (HDM) and hydrodesulfurization (HDS). We also discuss the composition and functions of hydrotreating catalysts, and we highlight areas for further improvement.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.495-500
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• 2011

Separation of naphthalene from pyrolyzed fuel oil, by product of Naphta cracking process (NCC) process, has been accomplished by the solvent extraction, distillation and purification process. The residual pyrolyzed fuel oil (PFO), called precursor of carbon materials, has been calcined at $300{\sim}800^{\circ}C$ in nitrogen gas to raw pitch. After the treatment of PFO by hexane and methanol, either a flake phased carbon at $350^{\circ}C$ or a carbon sphere at above $400^{\circ}C$ forms. As the calcination temperature increases, the shape of raw pitch changes from the flake phase to the sphere one, and the size of them decreases to several ${\mu}m$. Based on the BET and XRD spectrum, the carbon sphere is classified to a mesophase amorphous carbon with a cubic phase.

• Journal of Energy Engineering
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• v.22 no.4
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• pp.376-385
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• 2013

There are conflicts about energy price increase among government, producer, and consumer. The supplier insists on price increase for escaping running a deficit and business continuity, but the consumer concerns about worsening profitability and price rise. This study investigates the effects of energy rate increase on national economy using input-ouput(I-O) analysis. This study attempts to analyze the effects of national economy due to Coke and hard-coal, Naphtha, Gasoline, Kerosene, Light oil, Heavy oil, Liquefied petroleum gas, Electric utilities, Manufactured gas supply and Steam and hot water supply (using input-output table for the year 2011, Korea.) The results of the sectoral price changes due to a 10% increase in energy price that is obtained from the Leontief price model are presented in article. The result of this analysis is presented: The impact of the 10% increase in electricity rate on the general price level is estimated to be 0.2196%. In case of Kerosene, the impact is 0.1222%. It shows that Electric utilities are approximately 18 times larger price inducing effect as Kerosene. Also, this study indicates 3 years results sequentially to make it possible to observe trend. Then, study suggests balancing price by making each energy source adjusted.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.224-228
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• 2015

The carbon precursor pitch from pyrolyzed fuel oil (PFO), by-product of Naphta cracking process (NCC), was prepared through heat and UV irradiation treatments with various concentrations of $AlCl_3$, which is a new pitch preparation method. The reformed pitches were characterized by measuring their elemental composition, chemical structure of components, molecular weight distribution, and softening point. The oxygen contents of reformed pitch increased as increasing $AlCl_3$ amounts on the other hand, the carbon and hydrogen contents were not nearly changed. UV irradiated reformed pitches were composed of more aromatic carbon compounds than that of using only heat-treatment without any UV irradiation. The addition of $AlCl_3$ catalyst was ineffective on the aromaticity of reformed pitches. The softening point of prepared pitches was in the range of $103.3{\sim}168.9^{\circ}C$. Also the yield of prepared pitch increased from 48% to 80% when 5 wt% of $AlCl_3$ was added during the heat and UV irradiation reforming. It is expected that the UV irradiation reforming method can be practical and helpful to produce high yields of pitches with diverse properties.