• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1497-1502
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• 2013

When using hydrogen gas as an ecofriendly energy sources, it is necessary to conduct a safety assessment and ensure thereliability of the hydrogen pressure vessel against hydrogen embrittlement expected in the steel materials. In this study, by applying the in-situ SP test method, the gas hydrogen embrittlement behaviors in SA372 steel, which is commonly used as a pressurized hydrogen gas storage container, were evaluated. To investigate the hydrogen embrittlement behavior, SP tests at different punch velocities were conducted for specimens with differently fabricated surfaces at atmospheric pressure and under high-pressure hydrogen gas conditions. As a result, the SA372 steel showed significant hydrogen embrittlement under pressurized hydrogen gas conditions. The effect of punch velocity on the hydrogen embrittlement appeared clearly; the lower punch velocity case indicated significant hydrogen embrittlement resulting in lower SP energy. The fractographic morphologies observed after SP test also revealed the hydrogen embrittlement behavior corresponding to the punch velocity adopted. Under this pressurized gas hydrogen test condition, the influence of specimen surface condition on the extent of hydrogen embrittlement could not be determined clearly.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.71.1-71.1
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• 2011

석석탄가스화 기술은 고온, 고압 조건에서 미분탄과 산소의 가스화 반응에 의해 CO와 $H_2$가 주성분인 합성가스를 제조하는 기술로서 차세대 화력발전 뿐만아니라 다양한 화학원료 제조를 위한 분야에서 각광을 받고 있다. 또한, 가스화 기술은 향후 CCS기술, CTL(Coal To Liquid, 석탄액화)기술, SNG(Synthetic Natural Gas, 합성천연가스)생산, 수소생산, 각종 화학원료 생산 등과 연계가 가능한 미래 석탄이용 분야의 핵심 기술이라 할 수 있다. 따라서, 고등기술연구원에서는 이러한 석탄가스화를 통해 양질의 합성가스를 제조하기 위한 기술 개발의 일환으로 pilot급 고온, 고압 건식 분류층 가스화기, 기류수송 방식의 미분탄공급장치, 수냉자켓 구조의 합성가스 냉각장치, 합성가스 중 분진제거를 위한 금속필터 장착 집진장치 등을 연계하여 20기압의 고압 조건에서 장시간 연속운전을 진행하였다. 본 연구에서는 미분탄 공급을 위하여 상부공급 버너를 적용하였고 석탄가스화기는 $1,300{\sim}1,350^{\circ}C$ 정도의 온도에서 운전을 진행하였으며 미분탄을 75 kg/h의 조건에서 연속적으로 공급하였다. 그리고, 이러한 조건에서 5.5일 정도의 연속운전을 진행하는 동안 CO 44~48%, $H_2$ 20~21%, $CO_2$ 4~5% 조성의 석탄 합성가스를 $200Nm^3/h$ 안정적으로 제조할 수 있었다.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.3
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• pp.188-193
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• 2009

Fuel cell vehicles are equipped with Pressure Relief Devices(PRDs) installed in pressure tank cylinder to prevent the explosion of the tank during a fire. PRDs are safety devices that perceive a fire and release gas in the pressure tank cylinder before it is exploded. But if the PRD does not actuate, because either the PRD fails or can't be surrounded by the flame of a fire, the tank will rupture and produce a blast wave and hydrogen fire ball. In this paper, we observed the fire behavior of actual fuel cell vehicle, comparing with that of gasoline vehicle.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.685-693
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• 2011

In the era of energy climate, IGCC technology is one of the powerful solutions for the demands of new energy with low carbon green growth. The present study is conducted to investigate the combustion characteristics of syngas from the coal gasifier to predict problems when it is fed to the gas turbine. Through high and low combustion tests, we understood that hydrogen is the main reason of NOx emission but easily controled by injecting the dilution of nitrogen. CO emission of syngas was comparable with that of methane and pressure fluctuation of syngas was not significant. The data from this study will be used for the optimization of combustion in the Korea first IGCC plant in 2015.

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.156-160
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• 2004

The extraction rates of plasticizer of LPG high pressure rubber are studied. Submerging solvents are composed of propane, n-butane, n-pentane, n-hexane, n-heptane, propylene, 1,3-butadiene, 1-pentene, 1-hexene, ethanethiol, t-butanethiol, dimethyl sulfide, methyl ethyl sulfide. The relationship between the extraction rate of plasticizer and the descriptors of submerging solvent by using multiple linear regression is as follows; PE(wt%) = 7.5193 - 0.58500Carbon${\sharp}$ + 2.3294DB + 2364SH, (N = 13, F = 24.135, R$^2$ = 0.8894, R$_{adj}^2$ = 0.8526, Variance = 7.588) Plasticizer is well extracted by LPG composed of the high vapour pressure and polarity compounds. The mass of extracted plasticizer becomes increasing in proportion to the contents of thiol sulfur compound and unsaturated hydrocarbon such as propylene and 1,3-butadiene in LPG. While the heavier hydrocarbons are, the less the quantities of plasticizer extracted from rubber are.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.905-912
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• 2011

In this study, the novel concept catalytic reactor was designed for water-gas shift reaction (WGS) under high pressure. The novel concept catalytic reactor was composed of an autoclave, the catalyst, and liquid water. Cu-ZnO/$Al_2O_3$ as the low temperature shift catalyst was used for WGS reaction. WGS in the novel concept catalytic reactor was carried out at the ranges of 150~$250^{\circ}C$ and 30~50 atm. The liquid water was filled at the bottom of the autoclave catalytic reactor and the catalyst of pellet type was located at the gas-liquid water interface. It was concluded that WGS reaction occurred over the surface of catalysts partially wetted with liquid water. The conversion of CO for WGS was also controlled with changing content of Cu and ZnO used as the catalytic active components. Meanwhile, the catalyst of honey comb type coated with Cu-ZnO/$Al_2O_3$ was used in order to increase the contact area between wet-surface of catalyst and the reactants of gas phase. It was confirmed from these experiments that $H_2$/CO ratio of the simulated coal gas increased from 0.5 to 0.8 by WGS at gas-liquid water interface over the wet surface of honey comb type catalyst at $250^{\circ}C$ and 50 atm.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.5
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• pp.473-482
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• 2018

To check applicability of recently developed new oxygen carrier for 0.5 MWth chemical looping combustion system, reactivity tests were carried out at high temperature and high pressure conditions. Pressure, temperature, gas velocity, $CH_4$ flow rate, and solid height were considered as operating variables. The new oxygen carrier (N016-R4) showed not only high fuel conversion but also high $CO_2$ selectivity within all the operating conditions in this study. The reactivity of N016-R4 particle was compared with previous oxygen carriers. The N016-R4 particle represented outstanding reactivity among 10 oxygen carriers in terms of fuel conversion and $CO_2$ selectivity.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.194-201
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• 2020

Recently, Type 2 high-pressure hydrogen storage tank is studied due to fast defect detection, easy manufacturing, and cost efficiency. Moreover, the dry winding a high-strength metal wire will make increased economic efficiency compare with the wet winding method and the carbon/glass fiber winding method. In this study, a theoretical study on the dry winding of a Type 2 high pressure hydrogen tank using a metal wire was done, and the equations of the total stress on the aligned and the staggered winding for the hoop winding were derived, and the following results were obtained by using these equations. As the diameter of the metal wire, the number of winding layers, and the outer diameter of the liner increase, the maximum stress decreases, but the difference between the maximum stress occurring in the aligned winding and the staggered winding increases. As the pressure increases, the thickness of the winding layer increases, but as the strength of the metal wire increases, the thickness of the winding layer decreases. In addition, regardless of the strength of the metal wire, the thickness of the winding layer of the staggered winding was about 13.4% thinner than that of the aligned winding.

• Composites Research
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• v.21 no.1
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• pp.1-7
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• 2008

Composite vessels for high pressure gas storage are commonly used these days because of their competitive weight reduction ability maintaining strong mechanical properties. To supplement permeability of composite under high pressure, it is usually lined by metal, which is called a Type 3 vessel. However, it has many difficulties to design the Type 3 vessel because of its complex geometry, fabrication process variables, etc. In this study, therefore, GUI (graphic user interface) optimal design code for Type 3 vessels was developed based on semi-geodesic algorithm in which various factors of geometry and fabrication variables are considered and genetic algorithm for optimization. In addition, hydrogen vessels for 350/700 bar that can be applied to FCVs(fuel cell vehicles) were designed using this code for verification.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.1-6
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• 2008

For the safety design and operation of many gas process, it is necessary to know certain explosion limit, flash point, autoignition temperature (AIT) and minimum oxygen concentration of handling substances. Also it is necessary to know explosion limit at high temperature and pressure. In this study for the safe handling of hydrogen, explosion limit and AIT of combustion properties for hydrogen were investigated. By using the literatures data, the lower and upper explosion limits of hydrogen recommended 4.0 vol% and 77.0 vol%. Also the AIT of hydrogen with ignition sources recommended $400^{\circ}C$ at the electrically heated crucible furnace (the whole surface heating) and recommended $640^{\circ}C$ at the local hot surface. The new equations for predicting the temperature and the pressure dependence of the explosion limits of hydrogen are proposed. The values calculated by the proposed equations were a good agreement with the literature data.