• Title/Summary/Keyword: 이온교환막

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Recovery of $H_2SO_4$from Sulfuric Acid Wastes by Diffusion Dialysis (확산투석에 의한 황산폐액으로부터 황산의 회수)

  • 정진기;남철우;정강섭;이재천
    • Resources Recycling
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    • v.11 no.1
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    • pp.26-31
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    • 2002
  • The recovery of $H_2$$SO_4$from sulfuric acid waste was attempted by a diffusion dialysis method using an anion extchange membrane. The effect of flow rate, temperature, concentration of metal ions on the recovery rate was studied. The recovery of $H_2$$SO_4$decreased with the concentration of $H_2$$SO_4$and flow rate. The recovery increased with the flow rate ratio of water/$H_2$$SO_4$solution upto 1 above which no further increase was observed. The flow rate did not affect the rejection of Fe and Ni ions. As a result, about 80% of $H_2$$SO_4$could be recovered from sulfuric acid wastes which contains 4.5M free$-H_2$$SO_4$at the flow rate of 0.26 $1/hr-m^2$. The concentration and purity of recovered $H_2$$SO_4$was 4.3M and 99.8%, respectively.

The Effect of Additives on the Performance of Aqueous Organic Redox Flow Battery Using Quinoxaline and Ferrocyanide Redox Couple (수계 유기 레독스 흐름 전지 성능에서의 첨가제 효과)

  • Chu, Cheonho;Lee, Wonmi;Kwon, Yongchai
    • Korean Chemical Engineering Research
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    • v.57 no.6
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    • pp.847-852
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    • 2019
  • In this study, the effect of additives on the performance of aqueous organic redox flow battery (AORFB) using quinoxaline and ferrocyanide as active materials in alkaline supporting electrolyte is investigated. Quinoxaline shows the lowest redox potential (-0.97 V) in KOH supporting electrolyte, while when quinoxaline and ferrocyanide are used as the target active materials, the cell voltage of this redox combination is 1.3 V. When the single cell tests of AORFBs using 0.1 M active materials in 1 M KCl supporting electrolyte and Nafion 117 membrane are implemented, it does not work properly because of the side reaction of quinoxaline. To reduce or prevent the side reaction of quinoxaline, the two types of additives are considered. They are the potassium sulfate as electrophile additive and potassium iodide as nucleophilie additive. Of them, when the single cell tests of AORFBs using potassium iodide as additive dissolved in quinoxaline solution are performed, the capacity loss rate is reduced to $0.21Ah{\cdot}L^{-1}per\;cycle$ and it is better than that of the single cell test of AORFB operated without additive ($0.29Ah{\cdot}L^{-1}per\;cycle$).

The Effects of Different Membranes on the Performance of Aqueous Organic Redox Flow Battery Using Anthraquinone and TEMPO Redox Couple (안트라퀴논과 템포 활물질 기반 수계 유기 레독스 흐름 전지에서의 멤브레인 효과)

  • Lee, Wonmi;Kwon, Yongchai
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.695-700
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    • 2019
  • n this study, the evaluation of performance of AORFB using anthraquinone derivative and TEMPO derivative as active materials in neutral supporting electrolyte with various membrane types was performed. Both anthraquinone derivative and TEMPO derivative showed high electron transfer rate (the difference between anodic and cathodic peak potential was 0.068 V) and the cell voltage is 1.17 V. The single cell test of the AORFB using 0.1 M active materials in 1 M KCl solution with using Nafion 212 membrane, which is commercial cation exchange membrane was performed, and the charge efficiency (CE) was 97% and voltage efficiency (VE) was 59%. In addition, the discharge capacity was $0.93Ah{\cdot}L^{-1}$ which is 35% of theoretical capacity ($2.68Ah{\cdot}L^{-1}$) at $4^{th}$ cycle and the capacity loss rate was $0.018Ah{\cdot}L^{-1}/cycle$ during 10 cycles. The single cell tests were performed with using Nafion 117 membrane and SELEMION CSO membrane. However, the results were more not good because of increased resistance because of thicker thickness of membrane and increased cross-over of active materials, respectively.

Desalination of Boiled Oyster Extract by Electrodialysis (전기투석에 의한 굴자숙액의 탈염 특성)

  • 박표잠;이상훈;김세권
    • KSBB Journal
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    • v.15 no.2
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    • pp.167-173
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    • 2000
  • For selective elimination of salt from boiled oyster extract (BOE), electrodialyzer was used and the desalination conditions of B BOE were investigated. The ion-exchange membrane with a molecular weight cut off 100 Da was used for desalting of B BOE. The desalination efficiency at pH 4.0 was 13% higher than that at pH 9.0 when BOE was desalted for 90min. The e electrodialysis pro$\infty$ss could remove above 90% of the initial salt content when 5% BOE was desalted at pH 5.62 for 1 100min. The initial volume and concentration of permeation solution did not have significant effects on desalination time and r ratio. The important factors for the desalination of BOE were found to be pH and concentration of BOE. The results obtained prove that electrodialysis is a practical solution to the problem of selective elimination of salt from BOE.

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