• Title/Summary/Keyword: h2 Separation

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Preparation of Microporous Silica Membrane from TEOS-$H_2O$ System and Separation Of $H_2$-$N_2$ Gas Mixture (TEOS-$H_2O$계로부터 다공성 실리카 막의 제조 및 수소-질소 혼합기체의 분리)

  • 강태범;이현경;이용택
    • Membrane Journal
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    • v.10 no.2
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    • pp.55-65
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    • 2000
  • The porous silica membrane was prepared from Si(${OC}_2H_5)_4-H_2O$ system by sol-gel method. To investigate the characteristics of gels and porous silica membrane, we examined gels and porous silica membrane using TG-DTA, X-ray diffractometer, IR spectrophotometer, BET, SEM and TEM. The optimum mole ratio of Si(OC$_2$H$_{5}$)$_4$ : $H_2O$ $C_2$H$_{5}$OH for porous silica membrane was 1 : 4.5 : 4. The porous silica membrane was obtained by heat treatment of the gel above 700 $^{\circ}C$. The specific surface area of sintered gel was 3.8 $m^2$/g to 902.3 $m^2$/g at 100 $^{\circ}C$ to 1100 $^{\circ}C$ The pore size of sintered gel was in the range 20 $\AA$~ 50$\AA$. The particle size of sintered gel was 15 nm to 30 nm at 30$0^{\circ}C$ to 700$^{\circ}C$. The performance of the porous silica membrane was investigated for the separation of $H_2$/$N_2$ gas mixture. Gas separation through porous silica membrane depends upon Knudsen flow and surface flow. The veal separation factor($\alpha$) of $H_2$/$N_2$ was 5.17 at 155.15 cmHg and $25^{\circ}C$. The real separation factor($\alpha$), head separation factor($\beta$), and tail separation factor( $\bar{B}$) increased as the pressure of permeation cell Increased.sed.

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Separation of $H_2$/$N_2$ Gas Mixture by SiO$_2$-B$_2$O$_3$ Membrane (SiO$_2$-B$_2$O$_3$ 막에 의한 수소/질소 혼합기체 분리)

  • Kang Tae-Bum;Park Jin-Ho
    • Membrane Journal
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    • v.14 no.4
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    • pp.312-319
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    • 2004
  • The porous SiO$_2$-B$_2$O$_3$ membrane was prepared from Si(OC$_2$$H_5$)$_4$-($CH_3$O)$_3$B-C$_2$$H_5$OH-$H_2O$ system by sol-gel method. In order to investigate the characteristics of this membrane, we examined that using BET, IR spectrophotometer, X-ray diffractometer, SEM and TEM. At $700^{\circ}C$, the surface area of SiO$_2$-B$_2$O$_3$ membrane was 354.398 $m^2$/, the median pore diameter was 0.0048 ${\mu}{\textrm}{m}$, and the particle size of SiO$_2$-B$_2$O$_3$ membrane was 7 nm. The separation properties of the gas mixture ($H_2$/$N_2$) through the SiO$_2$-B$_2$O$_3$ membrane was studied as a function of pressure. The real separation factor($\alpha$) of SiO$_2$-B$_2$O$_3$ membrane for $H_2$/$N_2$ gas mixture was 4.68 at 155.15 cmHg and $25^{\circ}C$. The real separation factor($\alpha$), head separation factor($\beta$) and tail separation factor((equation omitted)) were increased as the pressure of permeation cell increased.

A Study on the Separation and Recovery of Magnesium from Waste Bittern (폐해수로부터 마그네슘의 분리.회수에 관한 연구)

  • Ju, Chang-Sik;Lee, Gyeong-Ok;Jeong, Seong-Uk;Park, Heung-Jae;Na, Seok-Eun;Jeong, Gap-Seon
    • Journal of Environmental Science International
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    • v.10 no.5
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    • pp.381-386
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    • 2001
  • The characteristics of precipitation separation and solvent extraction separation of magnesium from the waste bittern were studied experimentally In the result of precipitation separation, the size of magnesium hydroxide precipitated was not affected on pH, but decreased with increasing the precipitation temperature. The purity of magnesium oxide precipitated was increased with pH beyond pH 11. From the solvent extraction separation, the equilibrium extraction ratio of magnesium was increased with pH and temperature of extraction phase, the concentration of stripping phase, and with decreasing pH of stripping phase. The extractant of Aliquat 336 and Acid 810 mixture was more effective than that of DCH18C6 and $D_2EHPA$ mixture in the extraction separation of magnesium.

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Preparation and Properties of Hollow Fiber Membrane for CO2/H2 Separation (이산화탄소/수소 분리용 중공사형 기체분리막의 제조 및 특성)

  • Hyung Chul Koh;Mi-jin Jeon;Sang-Chul Jung;Yong-Woo Jeon
    • Membrane Journal
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    • v.33 no.4
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    • pp.222-232
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    • 2023
  • In this study, a hollow fiber support membrane was prepared by a non-solvent induced phase separation (NIPS) method using a polysulfone (PSf). The prepared hollow fiber support membrane was coated with PDMS and Pebax to prepare a hollow fiber composite membrane. The prepared composite membrane was measured for permeance and selectivity for pure CO2, H2, O2 and N2. Gas separation performance of the module having the highest selectivity (CO2/H2) among the prepared composite membrane modules was measured according to the change in stage cut using simulated gas. The composition of the simulated gas used at this time was 70% CO2 and 30% H2. In the 1 stage experiment, it was possible to obtain values of about 60% of H2 concentration and 12% of H2 recovery. In order to overcome the low H2 concentration and recovery, 2 stage serial test was performed, and through this, it was possible to achieve 70% H2 concentration and 70% recovery. Through this, it was possible to derive a separation process configuration for CO2/H2 separation.

Separation of $H_2$/$N_2$ Gas Mixture by PTMSP-PEI and PDMS-PEI Composite Membranes (PTMSP-PEI와 PDMS-PEI 복합막에 의한 수소/질소 혼합기체 분리)

  • 강태범;조성혜;이현경
    • Membrane Journal
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    • v.13 no.4
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    • pp.291-299
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    • 2003
  • Polymer membranes such as poly(1-trimethylsilyl-1-propyne)-polyetherimide (PTMSP-PEI) and poly(dimethylsiloxane)- polyetherimide (PDMS-PEI) composite membrane were prepared by solution casting method. To investigate the characteristics of these membranes, the analytical methods such as FT-IR, $^1H-NMR,$ DSC, TGA, GPC, and SEM have been utilized. The number-average (equation omitted) and weight-average (equation omitted) molecular weight of PTMSP were 477,920 and 673,329 respectively. The glass transition temperature ($T_g$) of PTMSP was $224^{\circ}C.$ The separation of the gas mixture ($H_2/N_2$) through the composite membranes were studied as a function of pressure. The separation factor (${\alpha}, {\beta},$ quation omitted) of the composite membranes used in this work increased as the pressure of permeation cell increased. The real separation factor (${\alpha}$), head separation factor (${\beta}$), and tail separation factor (equation omitted) of PTMSP-PEI composite membrane were 2.28, 1.17, and 1.96 respectively at ${\Delta}P$ 30psi and $25^{\circ}C.$ (${\alpha}, {\beta}$ and equation omitted of PDMS-PEI composite membrane were 3.70, 1.53, and 2.42 respectively at ${\Delta}P$ 30psi and $25^{\circ}C$.

Separation Characteristics of Oxygen Isotopes with Hydrophobic PTFE Membranes (소수성 PTFE 막의 산소동위원소 분리특성)

  • 김재우;박상언;김택수;정도영;고광훈;박경배
    • Membrane Journal
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    • v.13 no.3
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    • pp.154-161
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    • 2003
  • We measured the permeation characteristics of water with the hydrophobic PTFE membranes dependent on water temperature to confirm the separation of oxygen isotopes using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD). Isotopic concentrations of $H_2^{16}O$ and $H_2^{18}O$ of the permeated water vapor were measured by Diode Laser Absorption Spectroscopy. Concentrations of the heavy oxygen isotopes in the permeated water vapor were decreased. Isotope separation coefficients for the hydrophobic PTFE membranes were 1.004∼1.01 depending on the experimental conditions. We observed the effects of air in membrane pores on the oxygen isotope separation. Isotope separation coefficients for the hydrophobic PTFE membranes without air in pores are higher than those for the membrane with air in pores.

Analysis of Heavy Water Separation Cascade Using Bithermal ${H_2}$/$H_2$O Exchange Process

  • Ahn, Do-Hee;Paek, Seung-Woo;Lee, Han-Soo;Hongsuk Chung;Masami Shimizu
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11b
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    • pp.571-576
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    • 1996
  • The 3-stage cascade composed of the multisection-type bithermal $H_2$/$H_2O$-exchange columns was suggested for heavy water separation. In order to study the separation characteristics for the cascade, a matrix equation with 18 simultaneous equations was composed and the concentrations and flow rates were calculated for the all parts of the cascade. Product D-concentration decreases and extraction yield increases with increasing cut in each stage, which is one of the principal parameters of the separation characteristics. The optimization of the 3-stage cascade can be made by case study using the matrix equation.

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Polymeric Membrane Modules for Substituting the $CO_2$ Absorption Column in the DME Plant Process (DME 플랜트 $CO_2$흡수탑 대체용 고분자 분리막 모듈)

  • Chung, Jong-Tae;Lee, Choong-Seop;Koh, Hyung-Chul;Ha, Seong-Yong;Nam, Sang-Yong;Jo, Won-Jun;Baek, Young-Soon
    • Membrane Journal
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    • v.22 no.2
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    • pp.142-154
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    • 2012
  • In order to remove $CO_2$ from the DME plant process, we investigated the composite membrane with rubbery polymers as the separation layer and its separation performance of $CO_2$ and $H_2$. Hollow fiber membranes for supporting layer were prepared by solution spinning method. In case of using PDMS as a separation layer, the composite membranes showed the permeation rates of $CO_2$ were over 300 GPU and minimum $CO_2/H_2$ selectivitties were 4.3 and in case of using PEBAX as a separation layer, the composite membranes showed the permeation rates of $CO_2$ were over 120 GPU and minimum $CO_2/H_2$ selectivities were 5.

Separation of $H_2$/$N_2$ Gas Mixture by PTMSP/PDMS-PEI Composite Membrane (PTMSP/PDMS-PEI 복합막에 의한 수소/질소 혼합기체 분리)

  • Kang Tae-Bum;Hong Se-Lyung
    • Membrane Journal
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    • v.14 no.4
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    • pp.298-303
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    • 2004
  • PTMSP/PDMS-PEI composite membrane was prepared by solution casting method. To investigate the characteristics of this membrane, the analytical methods such as FT-IR, $^1$H-NMR, DSC, TGA, GPC, and SEM have been utilized. The number-average((equation omitted)) and weight-average((equation omitted)) molecular weight of PTMSP/PDMS copolymer were 501,516 and 675,560 respectively. The separation of the gas mixture($H_2$/$N_2$) through the composite membrane was studied as a function of pressure. The separation factor($\alpha$, $\beta$, (equation omitted)) of the composite membrane used in this work increased as the pressure of permeation cell increased. The real separation factor($\alpha$), head separation factor($\beta$), and tail separation factor ((equation omitted)) of PTMSP/PDMS-PEI composite membrane were 21.50, 49.14 and 1.84 respectively at $\Delta$P 345.55 kPa and $25^{\circ}C$.

Discovery of Porous Materials for H2/CO2 Gas Separation and High-Throughput Computational Screening (수소/이산화탄소 가스분리용 다공성 물질 탐색 및 고속전산스크리닝 연구동향)

  • Byung Chul Yeo
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.1-7
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    • 2023
  • Gas separation technology becomes more useful because key gases such as H2 and CO2 regarding renewable energy resources and environmental pollutant can be effectively extracted in mixed gases. For reducing energy consumption on gas separation, membrane and adsorption processes are widely used. In both processes, porous materials are needed as membrane and adsorbent. In particular, metal-organic frameworks (MOFs), one class of the porous materials, have been developed for the purpose of gas adsorption and separation. While the number of the MOF structures is increasing due to chemical and structural tunability, good MOF membranes and adsorbents have been rarely reported by trial-and-error experiments. To accelerate the discovery of high-performing porous materials that can separate H2 and CO2, a high-throughput computational screening technique was used as efficient skill. This review introduces crucial studies of porous materials and the high-throughput computational screening works focusing on gas separation of H2 and CO2.