• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.160-160
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• 2011

In this work, magnesium (Mg) nanoparticles were plated onto the surfaces of multi-walled carbon nanotubes (MWNTs) in order to investigate the effects of their presence on the high pressure hydrogen storage behaviors of the resultant Mg/MWNTs. The structure of Mg/MWNTs was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The pore structure and total pore volumes of Mg/MWNTs were analyzed by $N_2$/77 K adsorption isotherms. The hydrogen storage behaviors of the Mg/MWNTs were investigated by BEL-HP at 298K and 100 bar. From the results, it was found that Mg particles were homogeneously distributed on the MWNT surfaces. The hydrogen storage capacity increased in proportion to the Mg content. It can be concluded that Mg paricles play an important role in hydrogen storage characteristics due to the hydrogen spillover effect.

• 에너지공학
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• 제23권2호
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• pp.7-12
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• 2014

탄소나노튜브의 수소 저장소로써의 가능성을 평가하기 위한 분자 모사를 수행하였다. 일정한 온도와 압력에서 Grand canonical Monte Carlo 방법을 적용하여 탄소나노튜브에 수소가 흡착된 평형 상태를 구현하였다. Lennard-Jones 퍼텐셜 모델로부터 탄소나노튜브와 수소 분자 간 상호 작용 에너지를 계산 한 결과에 의하면 수소 분자는 나노튜브 외부보다 내부에 많은 양이 흡착되는 반면 흡착 강도는 외부가 높은 것으로 나타났다. 여러 가지 온도와 압력에 대해 흡착율을 검토하였으며, 200 K와 200 bar의 저온 고압 조건에서 약 2.5wt%의 흡착율을 나타내었다.

• 한국연초학회지
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• 제10권1호
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• pp.75-82
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• 1988

Cigarettes were made using a triple filter with several porous materials in its cavity. The removal effect of the adsorbents on carbon monoxide and hydrogen cyanide in cigarette smoke was investigated with the variation of their surface area and pore volume distributions. Several attempts were made to activated coconut shell based char under the fixed steam purging rate. 1. The specific surface area increased in number of micropore. It was found for transitional pore to have a little effect on the total surface area. 2. A Small amount of the particulate matter adsorbed on the adsorbents with transitional pores, Zeolite showed a little effect on the carbon monoxide adsorption though its small pore volume, but there was no significant difference in the adsorption capacity zeolite and the others. 3. In the adsorption for hydrogen cyanide as a vapor phase in cigarette smoke, the adsorption effect of the adsorbents increased remarkably with increasing their surface area and number of micropore. It was considered that the adsorbents with small pore volume like molecular seive 4A, in which the capillary diffusion of adsorbates could not be able, would not be effective for the adsorption of hydrogen cyanide.

• 한국수소및신에너지학회논문집
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• 제12권1호
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• pp.65-73
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• 2001

Carbon nanotubes were prepared by catalytic decomposition of $CH_4$ using Ni-MgO catalyst at various temperatures. $H_2$ effect on crystallinity and morphology during the synthesis of carbon nanotubes was investigated. The crystallinity and morphology were characterized by SEM, TEM, XRD, TGA, and Raman spectroscopy. In addition, the hydrogen adsorption properties were evaluated by PCT measurement in a hydrogen pressure range between 1 and 120 bar. The optimal synthesis temperature of carbon nanotubes was elevated in the presence of $H_2$, although significant difference of carbon nanotube morphology was not found. It is believed that hydrogen served as self-cleaner mops the amorphous carbon on the catalyst surface. It is proved that the carbon nanotubes have multi-walled structure, short length with a outer diameter of 20 ~40nm and open tips after elimination of the catalyst. The amount of hydrogen adsorbed in carbon nanotubes is increased as the pressure of hydrogen is increased and reaches 1.3 wt % under the hydrogen pressure of 120 bar at room temperature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.858-860
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• 1998

A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

• 한국수소및신에너지학회논문집
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• 제22권1호
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• pp.35-41
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• 2011

Temperature programmed reduction experiments for Fe- and Co-oxides were performed and weight losses were carefully measured to calculate the extent of reduction. Addition of nickel and palladium affected the reduction by lowering the DTG peak temperature. Reduction experiments for the oxides on alumina were also studied and the effect of nickel and palladium addition was confirmed. And that was explained by means of increased adsorption of hydrogen and increased diffusion ability of the surface hydrogen.

• 한국재료학회지
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• 제30권12호
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• pp.655-659
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• 2020

Hydrogen isotopes (i.e. deuterium and tritium) are supplied to the tokamak in the International Thermonuclear Experimental Reactor (ITER) fuel cycle. One important part of the ITER fuel cycle is the recycling of unused fuel back to the tokamak, as almost 99 % of fuel is unburned during fusion reaction. For this, cryogenic distillation has been used in the isotope separation system (ISS) of ITER, but this technique tends to be energy-intensive and to have low selectivity (typically below 1.5 at 24 K). Recently, efficient isotope separation by porous materials has been reported in the so-called quantum sieving process. Hence, in this study, hydrogen isotope adsorption behavior is studied using chemically stable ZIF-11. At low temperature (40 K ~ 70 K), the adsorption increases and the sorption hysteresis becomes stronger as the temperature increases to 70K. Molar ratio of deuterium to hydrogen based on the isotherms shows the highest (max. 14) ratio at 50 K, confirming the possibility of use as a potential isotope separation material.

• 한국의류학회지
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• 제18권5호
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• pp.622-627
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• 1994

The purpose of this study is to investigate the adsorption rate, adsorption quantities and the UV-Cut effects of cotton fabrics treated with several UV absorbents. The result of this study were as follows: cotton fabric treated with 2,2'-dihydroxy-4- methoxy-benzophenone shows more efficient than ones treated with 4-aminobenzoic acid and 2·hydroxy-1, 4-naphthoquinone in UV absorption. This may be due to the absorption of UV light by formation of intra moleculaar hydrogen bond. The formation of hydrogen bonds between hydrogen atoms of two hydroxy groups and one oxygen atom of carboxyl group in 2, 2'-dihydroxy-4-methoxy-benzophenone would be easier than that of the other absorbents. The adsorption isotherms of 4-aminobenzoic acid and 2-hydroxy-1, 4-naphthoquinone were similar to Freundlich type, while that of 2, 2'-Dihydroxy-4-methoxy-benzophenone was Henry type. Cotton fabrics treated with Antifade MC-100 and W Cut I-2 were just alike in UV absorption, but Antifade 8001 was inferior to the others.

• 한국진공학회지
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• 제1권1호
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• pp.78-82
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• 1992

W(123) 표면위에 수소와 중소수가 흡착될 때 일함수의 변화를 장방출(Field Fmission) 방법으로 측정하였다. 78K에서 이 분자들이 흡착될 때 일함수의 변화는 처음에 는 증가하다가 최대치에 이른 후 감소하였고, 덮임율(coverage)이 증가함에 따라 포화되었 다. 텅스텐 tip의 온도를 200K까지 올렸을 경우에, 일함수의 변화가 최대가 되었을 때의 덮 임율은 78K일 때의 비해 낮은 덮임율 쪽으로 이동하였고, [011] 방향을 갖는 step 혹은 terrace에 의한 일함수의 효과도 동시에 관측되었다.

• 한국수소및신에너지학회논문집
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• 제34권1호
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• pp.1-7
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• 2023

A fuel handling process combined with a pressure swing adsorption system (PSA) was simulated to produce pure hydrogen with a purity greater than 99.97%. The simulation consists of two parts. The fuel processing part consisting of reformer and water-gas shift reaction was simulated with Aspen plus^®, and the hydrogen purification part consisting of PSA was simulated with Aspen Adsorption^®. In this study, the effect of reformer temperature and pressure on the total hydrogen production yield was investigated. Simulations were performed over a temperature range of 700 to 1,000℃ and a pressure range of 1 to 10 bar. The total hydrogen production yield increased with increasing temperature and decreasing pressure. The maximum hydrogen yield was less than 50% in the simulation and will be lower in the real process.