• Title/Summary/Keyword: Chemical Pressure Vessel

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The study on the Hydrogen Characteristics of MmNi4.5Mn0.5 Hydrogen Storage Alloy (MmNi4.5Mn0.5계 수소저장합금의 수소화 특성에 관한 연구)

  • Kang, Kil-Ku;Kang, Sei-Sun;Kwon, Ho-Young;Lee, Rhim-Youl
    • Journal of Hydrogen and New Energy
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    • v.13 no.2
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    • pp.151-158
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    • 2002
  • The hydorgen storage alloys were produced by melting in arc melting furnace and then solution heat treated at $1,100^{\circ}C$ followed by pulverization. The chemical analysis on the samples showed that the major elements of misch metal(Mm) were La, Ce, Pr and Nd with impurity less than 1wt.%. X-ray diffraction indicated that the structure for these samples were a single phase of hexagonal with $CaCu_5$ type. Compared to the initial particle size $100{\sim}110{\mu}m$, the many fine cracks were found and particle size decreased to $14{\mu}m$ for $MmNi_{4.5}Mn_{0.5}$ after hydriding/dehydring test run. To activate the sample the vessel filled with hydrogen storage alloys was first evacuated for for at $70^{\circ}C$ and then treated for 10.5hr under hydrogen pressure of 20atm for $MmNi_{4.5}Mn_{0.5}$ alloy. The experimental data showed that the hydrogen storage alloy of $MmNi_{4.5}Mn_{0.5}$ had superior adsorption and description properties within a temperature rang of $40^{\circ}C{\sim}80^{\circ}C$ and also they had a good P-C-T curve.

Permeability and Strength of Cements Exposed to Supercritical CO2 for Varying Periods (초임계 CO2 - 시멘트 반응 전후의 투수율 및 강도 변화)

  • Lee, Hikweon;Kim, Kideok;Kim, Taehee;Kim, Gyo-Won
    • The Journal of Engineering Geology
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    • v.26 no.1
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    • pp.117-128
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    • 2016
  • Chemical reaction tests were performed to assess the properties of hardened specimens of cement pastes (KS-1 Portland and Class G) exposed to supercritical CO2 for 1, 10, and 100 days. After exposure, the samples' measured permeability and strength were compared with values measured for pristine samples. The pristine cements had permeabilities of 0.009~0.025 mD, which increased by one order of magnitude after 100 days of exposure (to 0.11~0.29 mD). The enhancement of permeability is attributed to the stress release experienced by the samples after removal from the pressure vessel after exposure. Despite its enhancement, the measured permeability mostly remained lower than the API (American Petroleum Institute) recommended maximum value of 0.2 mD. The degradation of the cement samples due to exposure to supercritical CO2 led to a layer of altered material advancing inwards from the sample edges. The Vickers hardness in the altered zone was much higher than that in the unaltered zone, possibly owing to the increase in density and the decrease in porosity due to the carbonation that occurred in the altered zone. Hardness close to the edge within the altered zone was found to have decreased significantly, which is attributed to the conversion of C-S-H into less-strong amorphous silica.

A Study of Consequence Analysis of Physical Explosion Damage in CO2 Storage Tank (CO2 임시 저장 탱크에서의 물리적 폭발에 따른 피해영향 고찰)

  • Seo, Doo-Hyoun;Jang, Kap-Man;Lee, Jin-Han;Rhie, Kwang-Won
    • Journal of the Korean Institute of Gas
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    • v.19 no.2
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    • pp.12-19
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    • 2015
  • $CO_2$ is non-flammable, non-toxic gas and not cause of chemical explosion. However, various impurities and some oxides can be included in the captured $CO_2$ inevitably. While the $CO_2$ gas was temporarily stored, the pressure in a storage tank would be reached above 100bar. Therefore, the tank could occur a physical explosion due to the corrosion of vessel or uncertainty. Evaluating the intensity of explosion can be calculated by the TNT equivalent method generally used. To describe the physical explosion, it is assumed that the capacity of a $CO_2$ temporary container is about 100 tons. In this work, physical explosion damage in a $CO_2$ storage tank is estimated by using the Hopkinson's scaling law and the injury effect of human body caused by the explosion is assessed by the probit model.

Kinetics of the Reaction of Carbon Dioxide with AMP and Piperazine (AMP에 Piperazine을 첨가한 CO2 흡수 동역학)

  • Jang, Sang-Yong;Song, Ju-Seouk;Cho, Sang-Won;Oh, Kwang-Joong
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.3
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    • pp.485-494
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    • 2000
  • According to the worldwide interest in controlling $CO_2$ which contributes to green house effect. new techniques of reducing $CO_2$ are under development. We have developed new technique for reducing $CO_2$. In low $CO_2$ concentration. the chemical absorption method is useful. In this study. the kinetics of the reaction between $CO_2$ and the sterically hindered amine solution with piperazine. have been investigated from measurements of the rate of absorption of $CO_2$ in the stirred vessel that has a horizontal liquid-gas interface, in the temperature range $30{\sim}70^{\circ}C$. The experiments were carried out in the range 10.130~20.260 kPa of partial pressure of $CO_2$, and in aqueous $2.0kmol/m^3$ AMP solution with $0{\sim}0.4kmol/m^3$ piperazine The experimental results are as follows: 1) The absorption rate of $CO_2$ into aqueous AMP + piperazine solution is gett ng faster than that of aqueous AMP absorbents with temperature. Because the activation energy of piperazine 57.147 kJ/mol is higher than that of AMP 41.7kJ/mol. therefore the effect of piperazine on absorption rate increases with temperature. 2) Compared with aqueous AMP solution. the absorption rate of $CO_2$ into AMP + piperazine solution increases from 6.33% at $30^{\circ}C$ to 12% at $70^{\circ}C$, so AMP + piperazine solution is thought to be a better than AMP solution, 3) The reaction rate constants of piprazine in aqueous AMP solution with $CO_2$ have been determined as 217.21, 420.46, 707.00 and $3162.167m^3/kmol{\cdot}s$ respectively at 30, 40, 50 and $70^{\circ}C$ but these results are higher than those of Xu which were 186.7. 367.32. 693.01. $2207.65m^3/kmol{\cdot}s$ at 30, 40, 55, $70^{\circ}C$in aqueous MDEA solution. So the regression analysis of the data has led to the following equation In $k_p$ =28.324-6934.7/T.

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