• Title/Summary/Keyword: 전해환원

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A study on the electrochemical reduction of carbon dioxide (전기화학환원에 의한 이산화탄소의 수소화 반응연구)

  • Sim, Kyu-Sung;Kim, Jong-Won;Kim, Yeon-Soon;Myeong, Kwang-Sik
    • Journal of Hydrogen and New Energy
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    • v.9 no.1
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    • pp.8-15
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    • 1998
  • The catalytic hydrogenation of carbon dioxide has been studied for the fixation of carbon dioxide to mitigate global warming problems, but it needed hydrogen, which the price is still high. Recently, the electrochemical reduction of carbon dioxide has been drawn attractions because carbon dioxide could be converted to the valuable chemicals such as methane, ethane and alcohols electrochemically in the electrolyte solution using a catalytic electrode. This system is simple because the water electrolysis and hydrogenation take place at the same time using the surplus electricity at midnight. In this work, a continuous electrochemical reduction system was fabricated, which was composed of the reduction electrode (copper or perovskite type, $2{\times}2cm^2$), reference electrode(platinum, $2{\times}6cm^2$), standard electrode(Ag/AgCl), and potassium bicarbonate electrolyte solution saturated with carbon dioxide. The quality and quantity of the products and reduction current were analyzed, according to the electrolyte concentration and electrode type.

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Current Status of Titanium Smelting Technology (타이타늄 제련기술 현황)

  • Sohn, Ho-Sang;Jung, Jae-Young
    • Resources Recycling
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    • v.25 no.4
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    • pp.68-79
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    • 2016
  • Titanium is the ninth most abundant element in the Earth's crust. It is also the forth most abundant structural metal after aluminum, iron and magnesium. Titanium is conventionally produced by the Kroll process. New processes to produce metallic titanium have been currently developed by many researchers in the world. In this study, the existing technologies, including both commercial and developmental processes, categorized into three groups: those by metallothermic reduction of $TiCl_4$ and $TiO_2$, those by electrolytic reduction of $TiO_2$ and hydrogen reduction of Ti compounds. Their mechanisms for reduction and their features are summarized and discussed in the view of industrial application.

Characteristics of Three-Component Carbonate Electrolytes in Terms of Oxygen Reduction and NiO Dissolution (산소환원 및 산화니켈의 용해거동으로부터 본 삼원계 탄산염 전해질의 특성)

  • Lee, C.G.;Taniguchi, T.;Uchida, I.
    • Journal of the Korean Electrochemical Society
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    • v.6 no.3
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    • pp.178-182
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    • 2003
  • The oxygen reduction and NiO dissolution behaviors in Li-Na-K three component carbonate melts have been investigated with various compositions through electrochemical and chemical ways. The oxygen reduction currents and NiO solubilities were measured at $650^{\circ}C$ and atmospheric condition in Li-Na-K =47.4-32.6-20, 60-20-20, 50-40-10, $40-40-20 mol\%$ carbonate melts. The oxygen reduction currents showed dependence on the composition, indicating oxygen solubility is a function of carbonate composition. At the composition of $ Li-Na-K=50-40-10 mol%$, a broader peak was observed, suggesting different oxygen reduction mechanism probably prevails in this composition. In contrast, insignificant differences of NiO solubility were obtained among the compositions.