• 한국수소및신에너지학회논문집
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• 제8권2호
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• pp.51-56
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• 1997

Laves상 $ZrV_2$합금은 다량의 수소를 저장하지만 수소와의 결합력이 강하여 Ni-MH전지의 전극으로는 부적당하다. 전극에 응용하기 위해 $ZrV_2$합금중의 V의 일부를 Ni로 치환하여 수소와의 결합력을 약하게 하였다. 이와 같은 Zr-V-Ni계 합금에 대해 전기화학적 성질, 전극의 평형전위로부터 합금중의 수소의 열역학적성질 및 2차전지전극에의 응용가능성을 조사하였다.

• 동아시아식생활학회지
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• 제7권3호
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• pp.325-329
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• 1997

본 세균의 성장과 수소생성을 위한 최적온도는 30-35$^{\circ}C$ 이었고 최적 pH는 7.0 부근이었다. 이 광합성 세균의 수소발생을 위한 전자전달계의 유기화합물은 포도당 또는 과당과 같은 당류와 malate 혹은 pyruvate 같은 유기산이 효율적임이 밝혀졌다. 이 결과는 Rhodobacter sphaeroides KS56이 전자전달계로서 여러종류의 환원성 탄수화물을 이용할 수 있음을 나타낸다.

• 한국수소및신에너지학회논문집
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• 제25권3호
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• pp.297-304
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• 2014

The purpose of this study is to evaluate the experimental performance characteristics of a water-to-water geothermal heat pump featuring a vapor refrigerant injection for the production of hot water. The performance of geothermal heat pump with a vapor injection was evaluated by comparing with that of a conventional geothermal heat pump without a vapor injection. For heating operation, the geothermal heat pump with a vapor injection is superior in COP and heating capacity. The vapor injection was more effective for supplying hot water while overloading. The vapor injection was effective for the improvement of the cooling capacity. However, the vapor injection was not effective for the increasing of COP according to the increased input of a compressor. The advantage of vapor injection in water-to-water geothermal heat pump become disappeared while cooling operation with lower part loading.

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.369-375
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• 2019

Air conditioners adopting high energy efficiency and low global warming potential (GWP) refrigerant are being developed globally. In case of commercial air conditioner, R32 with lower GWP than R410A is attracting industrial attentions. In this study, the performance of water-to-water geothermal heat pump adopting R32 is compared with that of the heat pump using R410A. By using R32 instead of R410A, heating capacity and COP in heating standard condition can be increased by 8.8% and 6.3% respectively. Also, cooling capacity and COP in cooling standard condition can be increased by 5.3% and 3.1% respectively by using R32. But in case of using R32, systemic improvements are required to decrease discharge temperature of compressor since discharge temperature rises abnormally in heating operations.

• 청정기술
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• 제23권1호
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• pp.113-117
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• 2017

본 연구에서는 섬유활성탄에 탄산나트륨을 첨착제로 이용하여 탄산나트륨 첨착섬유활성탄을 제조하고 동일조건에서 제조한 탄산나트륨 첨착입상활성탄과 황화수소 제거 성능을 비교한 후 그 활용가능성을 검토하고자 하였다. 첨착용액의 농도와 첨착시간을 변수로 하여 탄산나트륨 첨착섬유활성탄과 탄산나트륨 첨착입상활성탄의 흡착능을 구하였는데 먼저 두 경우 모두 첨착용액의 농도에 비례하여 탄산나트륨의 첨착되는 양도 증가하나 3 wt%이상에서는 기공충전(pore filling) 현상으로 첨착양에 변화가 없었다. 따라서 황화수소 제거를 위한 탄산나트륨 첨착섬유활성탄과 탄산나트륨 첨착입상활성탄의 제조시 최적의 탄산나트륨 용액 농도는 3 wt%인 것으로 판단되었다. 또한 탄산나트륨 첨착섬유활성탄의 경우 탄산나트륨 첨착을 위한 담지시간이 탄산나트륨 첨착입상활성탄에 비하여 2배 가까이 빠른 것으로 나타났다. 황화수소 제거효율은 탄산나트륨 첨착섬유활성탄이 탄산나트륨 첨착입상활성탄에 비하여 30% 이상 증가하였고 이는 비표면적의 측정결과로 설명되었다. 결과적으로 향상된 비표면적을 가진 섬유활성탄에 황화수소와 화학적으로 반응하는 탄산나트륨을 첨착하여 제조상 시간적 이점과 향상된 황화수소 흡착능을 확인할 수 있었다.

• 한국수소및신에너지학회논문집
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• 제18권3호
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• pp.325-333
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• 2007

[ $LiNi_{0.995}Al_{0.005}O_2$ ], $LiNi_{0.990}Ti_{0.010}O_2$ and $LiNi_{0.0990}Al_{0.005}Ti_{0.005}O_2$ were synthesized with a combustion method by calcining in an $O_2$ stream at $750^{\circ}C$ for 36 h. The X-ray diffraction patterns of these synthesized samples showed $-NaFeO_2$ structure of rhombohedral system(space group; $R{\bar{3}}\;m$) with no evidence of impurities. Among these samples, $LiNi_{0.995}Al_{0.005}O_2$ exhibited comparatively high first discharge capacity and discharge capacity, and the best cycling performance. $LiNi_{0.995}Al_{0.005}O_2$ had the first discharge capacity of 165.2 mA h/g and a discharge capacity of 116.7 mA h/g at the 50th cycle at 0.1C rate. It showed the first discharge capacity of 141.0 mA h/g and a discharge capacity of 93.5 mA h/g at the 50th cycle at 0.5C rate.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.744-744
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• 2009

The development of safe and suitable hydrogen storage materials is one of key issues for commercializing hydrogen as an energy carrier. Carbon based materials have been investigated for many years to store hydrogen by the adsorption of the gas on the surface of the carbon structure. Recently, it is reported that carbon nitride nanobells have high hydrogen storage capacity since the nitrogen atom plays an important role on attracting hydrogen molecules. Here we report carbon nitride microporous spheres (CNMS) which have the maximum surface area of 995.3 $m^2/g$. Melamine-Formaldehyde resin is the source of carbon and nitrogen in CNMS. Most of the CNMS pores have diameters in the range of 6 to 8 A which could give a penetration energy barrier to a certain molecule. In addition, the maximum hydrogen storage capacities of carbon nitride spheres are 1.9 wt% under 77 K and 1 atm.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.720-722
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• 2009

This work is mainly focused at developing the hydrogen production unit with the capacity of 20 $Nm^3/h$ of high purity hydrogen. At present steam reforming of natural gas is the preferable method to produce hydrogen at the point of production cost. The developed hydrogen production unit composed of natural gas reformer and pressure swing adsorption system. To improve the thermal efficiency of steam reforming reactor, the internal heat recuperating structure was adopted. The heat contained in reformed gas which comes out of the catalytic beds recovered by reaction feed stream. These features of design reduce the fuel consumption into burner and the heat duty of external heat exchangers, such as feed pre-heater and steam generator. The production rate of natural gas reformer was 41.7 $Nm^3/h$ as a dryreformate basis. The composition of PSA feed gas was $H_2$ 78.26%, $CO_2$ 18.49%, CO 1.43% and $CH_4$ 1.85%. The integrated production unit can produce 21.1 $Nm^3/h$ of high-purity hydrogen (99.997%). The hydrogen production efficiency of the developed unit was more than 58% as an LHV basis.

• 한국수소및신에너지학회논문집
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• 제18권4호
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• pp.382-390
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• 2007

To check the feasibility of SMART(Steam Methane Advanced Reforming Technology) system, an experimental investigation was performed. A fluidized bed reactor of diameter 0.052m was operated cyclically up to 10th cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone(domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) condition. The hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased. However, the average hydrogen concentration at 10th cycle was 82.5% and this value is also higher than that of SMR. Based on these results, we could conclude that the SMART system can replace SMR system to generate pure hydrogen without HTS (high tempeature shift), LTS (low temperature shift) and $CO_2$ separation process.

• 한국수소및신에너지학회논문집
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• 제1권1호
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• pp.31-39
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• 1989

Although it has been well known that many metal hydrides are promising to use for hydrogen storage and other applications, some difficulties still remain. Metal hydrides, particularly in powder form, have very poor thermal conductivity. The hydrogen storage alloys degrade intrinsically or extrinsically during repeated hydriding and dehydriding. Elimination of these problems is very important in the practical applications. In order to prevent degradation and to improve the thermal conductivity, the hydrogen storage characteristics of rare-earth type alloy encapsulated with Cu or Ni by means of chemical plating have been investigated. No changes has occured in hydrogen absorption capacity and equilibrium pressure even though the alloy powder is microencapsulated. The first hydrogen absorption rate of the alloy encapsulated increased considerably comparing to uncapsulated sample. In the case of encapsulating the fine powder ($>10{\mu}m$) and subsequent compacting by $8ton/cm^2$, shape of compact is maintained regardless of hydriding and dehydriding. The degree of degradation of the alloy caused by impurity gas of CO or $O_2$ was decreased prominently by encapsulation.