• 제목/요약/키워드: Hydriding combustion synthesis

검색결과 4건 처리시간 0.019초

수소화 연소합성법을 이용한 Mg-xNi 금속수소화물의 수소저장특성에 관한 연구 (Hydriding Behavior of an Mg-xNi Alloys Prepared in Hydriding Combustion Synthesis)

  • 김지호;최덕균;황광택;한정섭;김진호
    • 한국수소및신에너지학회논문집
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    • 제21권2호
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    • pp.123-128
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    • 2010
  • Hydriding combustion synthesis (HCS) can produce full hydrides of alloys and in a short time. The conventional process based on ingot metallurgy cannot produce Mg-based alloy easily with the desired composition and the cast product needs a ling activation process for the practical use of hydrogen storage. In this study, the hydriding properties of Mg-xNi (x=5, 13.5, 54.7wt.%) alloys prepared by hydriding combustion synthesis were evaluated. The hydrogen storage capacity and kinetics of HCS Mg-xNi alloys were strongly dependent on the content of Ni. The HCS Mg-13.5wt.%Ni alloy shows the hydriding behavior to reach the maximum capacity within 30 min. and the reversible $H_2$ storage of 5.3wt.% at 623 K.

자전연소합성법으로 제조한 80wt% AB2-15wt% Mg-5wt% Mm 금속수소화물의 cycling특성 (Cycling Properties of 80wt% AB2-15wt% Mg-5wt% Mm Metal Hydride made by Hydriding Combustion Synthesis)

  • 허태홍;한정섭
    • 한국수소및신에너지학회논문집
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    • 제22권5호
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    • pp.634-640
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    • 2011
  • The effect of cycling on the absorption and desorption characteristics of the 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm system was investigated. The material was made by Hydrogen Combustion Synthesis. The cycling experiment was performed at 298 K, 30 atm for 15 min. During the reaction time, the amount of absorption was fully desorbed. After the full activation, the hydrogen storage capacity was 1.57 wt% and the capacity was maintained until 50 cycles. And the reaction rate does not change with an increase in the number of cycles. This material has good durability and reversible feature.

자전연소합성법으로 제조한 Zr계 AB2-x Mx 금속수소화물의 수소저장특성 (Hydrogen Storage Properties of Zr-Based AB2-x Mx Metal Hydrides Made by Hydriding Combustion Synthesis (HCS))

  • 허태홍;한정섭;김진호
    • 대한금속재료학회지
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    • 제50권3호
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    • pp.256-262
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    • 2012
  • This study investigated the hydrogen storage properties of Zr-Based $AB_{2-x}M_x$ metal hybride made by HCS (Hydriding Combustion Synthesis). The materials were prepared by HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm, HCS 80 wt% $AB_2$-20 wt% Mg and pure Zr-Based $AB_2$, These materials were activated at 298 K under 20 bar. Both HCS 80 wt% $AB_2$-20 wt% Mg and HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm were absorbed within 1 minute. In the case of the $AB_2$, it was perfectly absorbed within 6 minutes. Then, the materials were evaluated to obtain P-C-T (Pressure-Composition-Temperature) curves at 298K. As a result, the hydrogen storage capacity of HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ were determined to be 1.2, 1.6 and 1.74 wt%, respectively. The activation energy and rate controlling step were calculated by the Johnson-Mehl Avrami equation. The activation energies of HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ were 26.91, 20.45, and 60.41 kJ/mol, respectively. Also, the values of ${\eta}$ in the Johnson-Mehl Avrami equation for HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ are 0.60, 0.51, and 0.44. So, the rate controlling steps which indicate hydrogen storage mechanism are an one dimensional diffusion process.

Mg-13.5wt%Ni 합금 수소화합물의 수소방출에 대한 부피법에 의한 열분석 (Volumetric Thermal Analysis of Hydrogen Desorption from Mg-13.5wt%Ni Hydride)

  • 한정섭;박경덕
    • 한국수소및신에너지학회논문집
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    • 제26권4호
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    • pp.308-317
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    • 2015
  • To investigate the effect of microstructure on the formation of the desorption peak, the volumetric thermal analysis technique (VTA) was applied to the Mg-13.5 wt% Ni hydride system. The sample made by the HCS (hydriding combustion synthesis) process had two kinds of Mg microstructures. Linear heating was started with various constant heating rates. Only one peak was appeared in the case of the small initial hydrogen wt% (0.83 wt%). Yet, two peaks were appeared with increasing initial hydrogen wt% (1.85 and 3.73 wt%) when only Mg was hydrogenated. The first peak was formed through the evolution of hydrogen from $MgH_2$, made by eutectic Mg. The second peak was formed through the evolution of hydrogen from $MgH_2$, made by primary Mg. Therefore, this result shows that the microstructure also has a considerable effect on forming the desorption peak. We have also derived the hydrogen desorption equations by VTA to get apparent activation energy when the rate-controlling step for the desorption of the hydrided system is the diffusion of hydrogen through the ${\alpha}$ phase and the chemical reaction ${\beta}{\rightarrow}{\alpha}$.