• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.58.2-58.2
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• 2012

Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1055-1061
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• 2000

The kinetics of tar formation has been studied experimentally and modeled mathematically for waste lubricating oil after pyrolyzed at batch reactor. And stabilization of pyrolyzed oil has been studied. A combination of series and parallel reaction was assumed for the mechanism of tar formation. From the proposed kinetic model, pyrolyzed oil to tar was found to be rate limiting step for tar formation. It was found that the fly ash and coke had the ability to remove materials of tar formation and to protect oxidation of pyrolyzed oil.

• Resources Recycling
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• v.9 no.6
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• pp.23-30
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• 2000

Since most of the waste plastics are incinerated and landfilled for the plastic treatment, the environmental friendly processes must be introduced. The plastic utilization of plastic to the blast furnace as a substitutional fuel was developed as a useful recycling method of waste plastics, and commercialized in several ironmaking company in Europe and Japan. Present study was carried out to understand the effect of plastic injection on blast furnace process continuously by using the foundry blast furnace in POSCO. The coke replacement ratio turned out to be 0.98 with the waste plastic injection up to 13.8 kg/thm of injection rate, and there were no significant effect of the kinds of injection plastics on the replacement ratio in this test operation. The permeability in the furnace became worse and the heat load in the lower part of blast furnace was increased with increasing the injection rate of waste plastics. As the rate of plastic injection were increased, the top gas utilization and shaft efficiency were also decreased from the Rist diagram analysis.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.481-486
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• 2021

In a hypersonic vehicle to solve the heat problem generated during flight, a cooling technology is being developed which uses the endothermic effect that appears during the decomposition reaction of the mounted fuel. In this study, the decomposition reaction of n-dodecane fuel was performed using HZSM-5 as a catalyst, and the catalyst was coated on metal foam to maximize the endothermic effect of the catalytic decomposition reaction and suppress coke formation. The reactor was a stainless steel flow reactor with a outer diameter of 1.27 cm, and the reaction temperature was 550 ℃, the reaction pressure was 4 MPa, and the flow rate was 12 ml per minute. As a result of the catalytic decomposition reaction using a catalyst coated with HZSM-5 on the metal foam, the heat sink was 2887 kJ/kg as a maximum, the gas phase conversion rate was 34%, and the amount of coke produced on the metal foam decreased by about 56% as the catalyst was coated compared to the uncoated catalyst.

• Clean Technology
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• v.24 no.4
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• pp.365-370
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• 2018

Oil shale is the sedimentary rock containing kerogen, which is one of the abundant unconventional fuel. In the pyrolysis process, oil, gas and coke are produced from the decomposition of oil shale. In this study, TGA and the continuous pyrolysis of oil shale have been investigated for the clean conversion of oil shale. Effects of reaction temperature and residence time on the pyrolysis conversion and oil production rate have been determined. Conversion of oil shale increases with increasing the reaction temperature and residence time. Optimum conditions for oil production were reaction temperature of $450{\sim}500^{\circ}C$ at the residence time of 30 min.

• Restorative Dentistry and Endodontics
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• v.47 no.1
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• pp.8.1-8.9
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• 2022

Objectives: The aim of this study was to compare the color change of the Giomer resin composite (Beautifil-Bulk) by using photographs obtained with a smartphone (iPhone 6S) associated with Adobe Photoshop software (digital method), with the spectrophotometric method (Vita Easyshade) after immersion in different pigment solutions. Materials and Methods: Twenty resin composite samples with a diameter of 15.0 mm and thickness of 1.0 mm were confectioned in A2 color (n = 5). Photographs and initial color readings were performed with a smartphone and spectrophotometer, respectively. Then, samples were randomly divided and subjected to cycles of immersion in distilled water (control), açai, Coke, and tomato sauce, 3 times a day, 20 minutes for 7 days. Later, new photographs and color readings were taken. Results: The analysis (2-way analysis of variance, Holm-Sidak, p < 0.05) demonstrated no statistical difference (p < 0.005) between the methods in all groups. Similar color changes were observed for all pigment solutions when using the spectrophotometric method. For the digital method, all color changes were clinically unacceptable, with distilled water and tomato sauce similar to each other and with statistical differences (p < 0.005) for Coke and açai. Conclusions: Only the tomato sauce produced a color change above the acceptability threshold using both methods of color assessment. The spectrophotometric and digital methods produce different patterns of color change. According to our results, the spectrophotometric method is more recommended in color change assessment.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.119-127
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• 2003

In this study we propose an unsteady I-dimensional model of bed combustion with multiple solid phases, which confers a phase on each solid material. This model can be applied to a variety of bed combustion cases of various configurations and ignition methods. It contains fuel combustion, gaseous reaction, heat transfers between each phase, and geometric changes of the solid particles. An iron ore sintering pot is selected for verifying the model validity and simulation results are compared with the limited experimental data set of various coke contents and air supply rates. They predict the experimental results well and show applicabilities to the various system of the fuel bed with various solid materials.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.165-166
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• 2014

The application of particle reaction model in the packed bed process modeling is discussed for iron ore pellet induration process. Combustion of coke breeze in the pellet is estimated by using shrinking unreacted-core model and grain model in which the progress of chemical reaction is described in different concepts. Under the identical inlet gas and solid conditions, the calculation using shrinking core model showed deviated results in terms of temperature profile and conversion fraction, which may imply the significance of selecting proper particle reaction model in consideration of particle characteristics and process operation conditions.

• Particle and aerosol research
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• v.12 no.2
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• pp.27-36
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• 2016

The PMF result was compared with the result from the Chemical Mass Balance (CMB) modelling (Lee and Kim, 2007) to estimate major source of PAHs observed at Seoul from August 2002 to December 2003. Five major sources were estimated from PMF and CMB modellings respectively. Among them three major sources (coal combustion for residential, coke oven and biomass burning) were identified at both models.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.3
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• pp.408-418
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• 1986

본 연구에서는 표면은 단단하고 내면은 강인한 조직을 얻기위하여 대형 성형 탄 로울에 대하여 노에서의 급속가열 및 대기 상태에서의 자연냉각의 열처리가 수행 되어진다. 급속가열 및 냉각시 성형탄 로울 내부의 온도 분포 예측을 위하여 대류 및 복사 열전달 경계조건을 가지는 1차원 비정상 열전도 방정식이 유한 차분법을 사 용하여 해석되어졌다. 여기서 급속가열시 연소가스로 부터 기체복사에 의하여 성 형탄 로울의 바깥표면을 통하여 흡수되는 열량은