• Title/Summary/Keyword: hydrogen separation

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Research Trends of Polybenzimidazole-based Membranes for Hydrogen Purification Applications (수소 분리 응용을 위한 폴리벤즈이미다졸 기반 분리막의 연구 동향)

  • Kim, Ji Hyeon;Kim, Kihyun;Nam, Sang Yong
    • Applied Chemistry for Engineering
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    • v.31 no.5
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    • pp.453-466
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    • 2020
  • As the demand for eco-friendly energy increases to overcome the energy shortage and environmental pollution crisis, hydrogen economy has been proposed as a potential solution. Accordingly, an economical and efficient hydrogen production is considered to be an essential industrial process. Research on applying hydrogen separation membranes for H2/CO2 separation to the production of highly concentrated hydrogen by purifying H2 and capturing CO2 simultaneously from synthetic gas produced by gasification is in progress nowadays. In high temperature environments, the membrane separation process using glassy polymeric membrane with H2 selectivity has the potential for CO2 capture performance, and is an energy and cost effective system since polybenzimicazole (PBI)-based separators show excellent chemical and mechanical stability under high-temperature operation conditions. Thus, the development of high-performance PBI hydrogen separators has been rapidly progressing in recent years. This overview focuses on the recent developments of PBI-based membranes including structure modified, cross-linked, blended and carbonized membranes for applications to the industrial hydrogen separation process.

Pd-based metallic membranes for hydrogen separation and production

  • Tosti, Silvano;Basile, Angelo
    • Proceedings of the Membrane Society of Korea Conference
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    • 2003.07a
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    • pp.25-28
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    • 2003
  • Low cost composite metallic membranes for the hydrogen separation and production have been prepared by using thin Pd-Ag foils reinforced by metallic (stainless steel and nickel) structures. Especially, “supported membranes” have been obtained by a diffusion welding procedure in which Pd-Ag thin foils have been joined with perforated metals (nickel) and expanded metals (stainless steel): in these membranes the thin palladium foil assures both the high hydrogen permeability and the perm-selectivity while the metallic support provides the mechanical strength. A second studied method of producing "laminated membranes" consists of coating non-noble metal sheets with very thin palladium layers by diffusion welding and cold-rolling. Palladium thin coatings over these metals reduce the activation energy of the hydrogen adsorption process and make them permeable to the hydrogen. In this case, the dense non-noble metal has been used as a support structure of the thin Pd-Ag layers coated over its surfaces: a proper thickness of the metal assures the mechanical strength, the absence of defects (cracks, micro-holes) and the complete hydrogen selectivity of the membrane. membrane.

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Hydrogen Perm-Selectivity Properties of the Pd-Ni-Ag Alloy Hydrogen Separation Membranes with Various Surface Nickel Composition (표면 니켈 조성에 따른 팔라듐-니켈-은 합금 수소분리막의 수소투과선택 특성)

  • Lim, Da-Sol;Kim, Se-Hong;Kim, Do-Hui;Cho, Seo-Hyun;Kim, Dong-Won
    • Journal of the Korean institute of surface engineering
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    • v.51 no.5
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    • pp.277-290
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    • 2018
  • In this study, Pd-Ni-Ag alloy hydrogen separation membranes were fabricated by Pd/Ag/Pd/Ni/Pd multi-layer sputter deposition on the modified MIM(Metal Injection Molding)-PSS(Porous Stainless Steel) support and followed heat treatment. Nickel, used as an alloying element in Pd alloy membranes, is inexpensive and stable material in a hydrogen isotope environment at high temperature up to 1123 K. Hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes is affected not only by composition of membrane films but also by other factors such as surface properties of PSS support, microstructure of membrane films and inter-diffused impurities from PSS support. In order to clarify the effect of surface Ni composition on hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes, the other effects were significantly minimized by the formation of dense and homogeneous Pd-Ni-Ag alloy membranes. Hydrogen permeation test showed that hydrogen permeability decreased from $7.6{\times}10^{-09}$ to $1.02{\times}10^{-09}mol/m{\cdot}s{\cdot}Pa^{0.5}$ as Ni composition increased from 0 to 16 wt% and the selectivity for $H_2/N_2$ was infinite.

Effects of Nickel Supports on Hydrogen Permeability of Vanadium based Membrane (니켈 지지체를 이용한 바나듐기 분리막의 수소 투과특성)

  • Cho, Kyoungwon;Choi, Jaeha;Jung, Seok;Kim, Raymundk.I.;Hong, Taewhan;Ahn, Joongwoo
    • Journal of Hydrogen and New Energy
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    • v.24 no.3
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    • pp.200-205
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    • 2013
  • The separation of hydrogen depends on porosity, diffusivity and solubility in permeation membrane. Dense membrane is always showing a solution diffusion mechanism but porous membrane is not showing. Therefore, porous membrane has a good hydrogen flux due to pore is carried out transferred media. This mechanism is named as the Knudsen diffusion. Hydrogen molecules or hydrogen atoms are diffused along pore that is a mean free path. In this study, complex layer hydrogen permeation membrane was fabricated by hot press process. And then, it was evaluated and calculated to relationship between hydrogen permeability and membrane porosity.

Experiment and Simulation of PSA Process for $H_2/Ar$ Mixtures gas ($H_2/Ar$ 혼합기체의 PSA 공정 실험과 모사)

  • Kang, Seok-Hyun;Jeong, Byung-Man;Choi, Hyun-Woo;Kim, Sung-Hyun;Lee, Byung-Kwon;Choi, Dae-Ki
    • Journal of Hydrogen and New Energy
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    • v.16 no.2
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    • pp.180-190
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    • 2005
  • The PSA cycle was performed for the separation of binary gas mixture $H_2/Ar$ (80%/20%) using the six-step two-bed process. Adsorption equilibrium contains a LRC model for equilibrium adsorption isotherms and a LDF model for mass transfer. Aspen ADSIM, simulator was applied to predict the separation performance. The effect of cycle parameters such as feed rate, adsorption pressure and P/F ratio on the separation of hydrogen has been studied in experiment and simulation. In the results, maximize the recovery of hydrogen as a high purity was 13LPM feed flowrate, 120sec adsorption time, 11atm adsorption pressure and 0.1 P/F ratio in a cyclic steady-state come out since 10th cycle.

Fabrications and Evaluations of Hydrogen Permeation on TIN-M(Co, NI) Composite Membrane (TIN-M(M=Co, NI) 복합 분리막의 제조 및 수소투과 특성평가)

  • Kim, Kyeong-Il;Yoo, Sung-Woong;Hong, Tae-Whan
    • Journal of Hydrogen and New Energy
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    • v.21 no.4
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    • pp.264-270
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    • 2010
  • Recently, the most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, TiN powders are great in resistance to acids and chemically stable under high operating temperature. In order to get specimens for hydrogen permeation, the TiN powders synthesized were consolidated together with Co, Ni powders by hot press sintering (HPS). During the consolidation of powders at HPS, heating rate was 10 K/min and the pressure was 10 MPa. It was characterized by XRD, SEM. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.

$Ba(Zr_{0.85}Y_{0.15})O_{3-\delta}$-NI Composite Membrane for Hydrogen Separation by Aerosol Deposition Method (에어로졸 증착법(Aerosol Depostion method)에 의한 $Ba(Zr_{0.85}Y_{0.15})O_{3-\delta}$-NI 수소분리막 제조)

  • Park, Young-Soo;Choi, Jin-Sub;Byoun, Myoung-Sub;Kim, Jin-Ho;Hwang, Kwang-Taek
    • Journal of Hydrogen and New Energy
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    • v.21 no.4
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    • pp.271-277
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    • 2010
  • $(Ba(Zr_{0.85}Y_{0.15})O_{3-\delta})$ oxide, showing high protonic conductivity at high temperatures and good chemical stability with $CO_2$ are referred to as hydrogen separation membrane. For high efficiency of hydrogen separation ($H_2$ flux and selectivity) and low fabrication cost, ultimate thin and dense BZY-Ni layer has to be coated on a porous substrate such as $ZrO_2$. Aerosol depostion (AD) process is a novel technique to grow ceramic film with high density and nano-crystal structure at room-temperature, and may be applicable to the fabrication process of AD integration ceramic layer effectively. XRD, SEM, X-ray mapping measurements were conducted in order to analyze the characteristics of BZY-Ni membrane fabricated by AD process. it is observed that it is homogeneous distribution for BZY-Ni. The result of $H_2$ permeation rate suggests that BZY-Ni composite is higher than BZY.

Fabrication and Hydrogen Separation Performance of Newly Created Ti-Based Alloy Membrane (신조성의 Ti-기반 합금 수소분리막의 설계 및 수소투과 성능)

  • Min Yeong Ko;Min Chang Shin;Xuelong Zhuang;Jae Yeon Hwang;Sung Woo Han;Si Eun Kim;Jung Hoon Park
    • Membrane Journal
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    • v.34 no.2
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    • pp.146-153
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    • 2024
  • In this experiment, a Ti-based flat hydrogen separation membrane was designed and manufactured. In order to find a Ti-based hydrogen separation membrane of a new composition, the correlation between the physical-chemical properties and hydrogen permeability of various alloys was investigated. Based on this, two types of new alloy films (Ti14.2Zr66.4Ni12.6Cu6.8 (70 ㎛), Ti17.3Zr62.7Ni20 (80 ㎛)) was designed and manufactured. The manufactured flat hydrogen separation membrane was tested for hydrogen permeation using mixed gas (H2, N2) and sweep gas (Ar) at 300~500℃ and 1~4 bar. The Ti14.2Zr66.4Ni12.6Cu6.8 alloy film has a maximum flux of 16.35 mL/cm2 min at 500℃ and 4 bar, and the Ti17.3Zr62.7Ni20 alloy film has a maximum flux of 10.28 mL/cm2 min at 450℃ and 4 bar.

Large-Scale PSA Process for Hydrogen Separation from Gas Mixture (혼합가스에서 수소분리를 위한 애용량 PSA공정)

  • Choi, Dae-Ki;Jin, Yin-Zhe;Kang, Seok-Hyun;Row, Kyung-Ho
    • Journal of Hydrogen and New Energy
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    • v.17 no.1
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    • pp.8-20
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    • 2006
  • For large scale separation hydrogen from different mixing ratio(60/40 and 80/20 vol.%) of hydrogen and methane $1Nm^3/hr$ and $4Nm^3/hr$ 2bed-6step pressure swing adsorption(PSA) process was used, respectively. The effects of the feed gas pressure, adsorption time, the feed flow rate and the P/F(purge to feed) ratio on the process performance were evaluated. In the $1Nm^3/hr$ PSA results, 11 atm adsorption pressure and 0.10 P/F ratio might be optimal values to obtain more than 75 % recovery and 99 % purity hydrogen in these processing. The optimum feed flowrate was 22 LPM and 17 LPM in the ratio 60/40 and 80/20, respectively. In the $4Nm^3/hr$ PSA results, 10 atm adsorption pressure might be simulated values to obtain more than 80 % recovery and 99 % purity hydrogen in these processing.

Hydrogen Generation Characteristics of SMART System with Inherent $CO_2/H_2$ Separation ($CO_2/H_2$ 원천분리 SMART 시스템의 수소생산특성)

  • Ryu, Ho-Jung
    • Journal of Hydrogen and New Energy
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    • v.18 no.4
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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.