• Title/Summary/Keyword: gas adsorption

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Pridiction of Adsorption Equilibrium for Binary Gas Mixtures on Cation Exchanged Forms of ZSM-5

  • Going Yim;Chai Suck Yim
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.85-98
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    • 2004
  • The adsorption equilibrium data for the binary gas mixture system from the pure gas adsorption data of carbon dioxide and ethylene on ZSM-5 prepared were predicted. The binary gas mixture adsorption data have been examined against predicted values by two models-the vacancy solution model(VSM) and the statistical thermodynamic model(STM), using parameters obtained from the single component isotherm. The binary gas mixture data for the carbon dioxide-ethylene system were obtained for cation exchanged forms of ZSM-5 for the gas phase carbon dioxide mole fraction of 0.752 at $37^{\circ}C$ and 1 atm. The experimental adsorption phase diagrams were obtained for carbon dioxide-ethylene on sodium form ZSM-5 synthesized. The single component adsorption isotherms for carbon dioxide and ethylene were also obtained for this zeolite. The single component data were used to obtain parameters derived in two models. These parameters were, in turn, used to predict the binary mixture isotherms for this zeolite. Both the vacancy solution and the statistical thermodynamic models give satisfactory predictions of adsorption phase diagrams for the binary gas mixtures of carbon dioxide and ethylene on sodium exchanged ZSM-5. Also the correlation between the experimental data and the predicted values is generally in good agreement. The system appears to show ideal behavior with a relatively constant separation factor. The slight increase in adsorption capacity with an increase in ionic radius is due, in part, to the higher polarizability associated with larger cations.

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Pressure Swing Adsorption Based Hydrogen Purification Vessel 3D Modeling and Feasibility Study (Pressure Swing Adsorption 기반 수소정제용기 3차원 모델링 및 타당성 검증 연구)

  • CHA, YOHAN;CHOI, JAEYOO;JU, HYUNCHUL
    • Journal of Hydrogen and New Energy
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    • v.32 no.4
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    • pp.197-204
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    • 2021
  • Pressure swing adsorption is a purification process which can get pure hydrogen. The purification process is composed of four process: compression, adsorption, desorption and discharge. In this study the adsorption process was simulated by using the Fluent and validated with experimental results. A gas used in experiment is composed of H2, CO2, CH4, and CO. Adsorption process conducted under 313 kelvin and 3 bar and bituminous-coal-based (BPL) activated carbon was used as the adsorbent. Langmuir model was applied to explain the gas adsorption. And diffusion of all the gases was controlled by micro-pore resistances. The result shows that, the most adsorbed gas was carbon dioxide, followed by methane and carbon monoxide. And carbon monoxide took the least amount of time to reach the maximum adsorption amount. The molar fraction of the off-gas became the same as the molar fraction of the gas supplied from the inlet after adsorption reached the equilibrium.

Effect of Pore Geometry on Gas Adsorption: Grand Canonical Monte Carlo Simulation Studies

  • Lee, Eon-Ji;Chang, Rak-Woo;Han, Ji-Hyung;Chung, Taek-Dong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.901-905
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    • 2012
  • In this study, we investigated the pure geometrical effect of porous materials in gas adsorption using the grand canonical Monte Carlo simulations of primitive gas-pore models with various pore geometries such as planar, cylindrical, and random pore geometries. Although the model does not possess atomistic level details of porous materials, our simulation results provided many insightful information in the effect of pore geometry on the adsorption behavior of gas molecules. First, the surface curvature of porous materials plays a significant role in the amount of adsorbed gas molecules: the concave surface such as in cylindrical pores induces more attraction between gas molecules and pore, which results in the enhanced gas adsorption. On the contrary, the convex surface of random pores gives the opposite effect. Second, this geometrical effect shows a nonmonotonic dependence on the gas-pore interaction strength and length. Third, as the external gas pressure is increased, the change in the gas adsorption due to pore geometry is reduced. Finally, the pore geometry also affects the collision dynamics of gas molecules. Since our model is based on primitive description of fluid molecules, our conclusion can be applied to any fluidic systems including reactant-electrode systems.

Adsorption Characteristics of Activated Carbons According to Impregnation Concentrations and Inlet CO2 Gas Concentrations (함침농도와 CO2 가스 유입농도에 따른 활성탄의 흡착특성)

  • Lee, Dong-Hwan;Kam, Sang-Kyu;Lee, Song-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1403-1407
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    • 2010
  • The adsorption characteristics of $CO_2$ gas on impregnated activated carbons with MEA (Mono-ethanolamine) and AMP (2-Amino 2-methyl 1-propanol) were studied to improve the adsorption ability of $CO_2$ gas on activated carbon. The equilibrium adsorption capacity of $CO_2$ gas was increased by increment of impregnation concentration up to 40 %, but decreased above 50 %. The adsorption capacity of activated carbon impregnated with AMP was higher than activated carbon impregnated with MEA. The breakthrough was fast according to increment of inlet concentration of $CO_2$ gas.

The Effect on Gas Adsoption Efficiency for Various Surface Characteristics (표면특성에 따른 물맺힘 특성이 가스흡착성에 미치는 영향)

  • 허경욱;신종민
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.8
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    • pp.671-675
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    • 2002
  • The gas adsorption efficiency for various surfaces with three different characteristics has been reviewed. The dimethyl disulfide gas has been used to investigate characteristics of gas adsorption for different surface characteristics such as plasma treated, lacquer coated and untreated. Three different surfaces were evaluated in dry conditions initially and tested at wet surface conditions with spraying water to evaluate the gas adsorption efficiency which usually occurred at defrost cycles. The results show that the gas adsorption of the plasma treated sample has better performance than others. The lacquer coated and untreated samples showed the similar result, but the lacquer coated sample showed a slightly better performance.

Development of Volume Modified Sorption Model and Prediction for Volumetric Strain of Coal Matrix (흡착에 의한 석탄암체의 부피변화가 고려된 흡착모델 개선 및 부피변형률 예측)

  • Kim, Sang-Jin;Sung, Won-Mo
    • Journal of the Korean Institute of Gas
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    • v.19 no.2
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    • pp.37-44
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    • 2015
  • We proposed the improved Langmuir adsorption relations considering volume change effect of coal matrix during primary production of CBM and Enhanced-CBM with injection of carbon dioxide or CCS in coalseam but also volumetric strain. To verify this model, experimental data of pure gas adsorption such as $CO_2$, $CH_4$, and $N_2$ on coals were used to compare conventional Langmuir model with this model. From the results, we obtained that the larger adsorption capacity of coal and the higher adsorption affinity of gas, the larger error occur with Langmuir model. Using this model, however, we found not only substantially better fit in all condition but also reasonable volumetric strain of the coal matrix. We also applied this volume modified pure gas adsorption model to the IAS model to describe gas adsorption and volumetric strain for mixed gas. This modified-IAS model fitting experimental data by Hall et al(1994) improved accuracy of mixed gas adsorption calculation compared with conventional model.

Development of Inner Packaging Material for Maintaining the Freshness of Fruits and Vegetables

  • Won, Jong-Myoung;Song, Je-Yun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.1 s.119
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    • pp.64-68
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    • 2007
  • The oak and pine charcoal were used to develop the inner packaging material for maintaining the freshness of vegetables and fruits, and to investigate the possibility in the application for inner packaging. The effects of the charcoal type, species, particle size, and grammage on the adsorption efficiency of ethylene gas were studied. White charcoal has superior ethylene gas adsorption performance to those of black charcoal. Pine charcoal was superior to oak charcoal in the ethylene gas adsorption. Higher gas adsorption was obtained by the higher grammage sheet. The difference in the adsorption efficiency was not significant between ONP and KOCC.

Quantitative Analysis of SO2 and NO2 Adsorption and Desorption on Quartz Crystal Microbalance Coated with Cobalt Gallate Metal-Organic Framework

  • Junhyuck Ahn;Taewook Kim;Sunghwan Park;Young-Sei Lee;Changyong Yim
    • Journal of Sensor Science and Technology
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    • v.32 no.3
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    • pp.147-153
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    • 2023
  • Metal-organic frameworks (MOFs) of cobalt gallate were synthesized and deposited on gold electrodes using self-assembly monolayers (SAMs) and hydrothermal processing. These MOF films exhibit strong adsorption capabilities for gaseous particulates, and the use of SAMs allows the synthesis and deposition processes to be completed in a single step. When cobalt gallate is mixed with SAMs, a coordination bond is formed between the cobalt ion and the carboxylate or hydroxyl groups of the SAMs, particularly under hydrothermal conditions. Additionally, the quartz crystal microbalance (QCM) gas sensor accurately measures the number of particulates adsorbed on the MOF films in real-time. Thus, the QCM gas sensor is a valuable tool for quantitatively measuring gases, such as SO2, NO2, and CO2. Furthermore, the QCM MOF film gas sensor was more effective for gas adsorption than the MOF particles alone and allowed the accurate modeling of gas adsorption. Moreover, the QCM MOF films accurately detect the adsorption-desorption mechanisms of SO2 and NO2, which exist as gaseous particulate matter, at specific gas concentrations.

Adsorption and Desorption Dynamics of Ethane and Ethylene in Displacement Desorption Process using Faujasite Zeolite (제올라이트(faujasite)를 이용한 치환탈착공정에서 에탄, 에틸렌의 흡, 탈착 동특성)

  • Lee, Ji-In;Park, Jong-Ho;Beum, Hee-Tae;Yi, Kwang-Bok;Ko, Chang-Hyun;Park, Sung Youl;Lee, Yong-taek;Kim, Jong-Nam
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.768-775
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    • 2010
  • Adsorption dynamics of ethane/ethylene mixture gas and desorption dynamics during the displacement desorption with propane as a desorbent in the column filled with faujasite adsorbent were investigated experimentally and theoretically. The simulation that adopted heat and mass balance and an ideal adsorbed solution theory (IAST) for the multicomponent adsorption equilibrium well predicted the experimental breakthrough curves of the adsorption and desorption. At the adsorption breakthrough experiments, roll-ups of ethane increased as the adsorption pressure increased and the adsorption temperature decreased. During the displacement desorption with propane in the column saturated with ethane/ethylene mixture gas, almost 100% of ethylene was obtained for a certain time interval. The adsorption strength of the desorbent greatly affected the adsorption and re-adsorption dynamics of ethylene. The re-adsorption capacity for ethylene has been greatly reduced when iso-propane, which is stronger desorbent than propane, was used as desorbent. It was found from the simulation that the performance of the displacement desorption process would be superior when the ratio of ${(q_s{\times}b)}_{C_2H_4}/{(q_s{\times}b)}_{C_3H_s}$ was 0.83, that is, the adsorption strengths of ethylene and the desorbent were similar.

Development of Charcoal Containing Paper for Packing Grades( I ) - Ethylene Gas Adsorption - (숯을 활용한 포장재 개발에 관한 연구 (제1보) - 에틸렌 가스흡착 -)

  • Seo, Young-Bum;Jeon, Yang;Lee, Hwa-Hyung;Jung, Tae-Young;Lee, Jong-Seok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.2
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    • pp.46-51
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    • 2003
  • The charcoal is known to have gas adsorption capability and is used frequently to mitigate the unpleasant smells from food and clothing. It is also used to treat water to remove dissolved organic and inorganic substances. In this paper, we applied the several different kinds of charcoals to the papers in three different ways to investigate if charcoal application method affects its gas adsorption capability. Wet end addition, making multiply, and coating method were tested. Specific ethylene gas adsorption capabilities were measured. Experimental results shows that manufacturing conditions of the charcoal itself changed its gas adsorption properties. The boxes used for agricultural produces, and the packaging paper for flowers are to be well fitted application for the charcoal added paper. Mulch paper, which needs opacity and air permeability with proper strength properties, is another candidate for the application of charcoal added paper.