• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.559-567
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• 2011

This paper deals with an economic evaluation of domestic low-temperature water electrolysis hydrogen production. We evaluate the economic feasibility of on-site hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ by the alkaline and the polymer electrolyte membrane water electrolysis. The hydrogen production prices of the alkaline water electrolysis, the polymer electrolyte membrane water electrolysis, and the steam methane reforming hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ were estimated as 18,403 $won/kgH_2$, 22,945 $won/kgH_2$, 21,412 $won/kgH_2$, respectively. Domestic alkaline water electrolysis hydrogen production is evaluated as economical for small on-site hydrogen fueling stations, and we need to further study the economic evaluation of low-temperature water electrolysis hydrogen production for medium and large scale on-site hydrogen fueling stations.

• Journal of the Korean Electrochemical Society
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• v.26 no.2
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• pp.19-34
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• 2023

Due to the intermittency of renewable energy sources, a need to store and transport energy will increase. Hydrogen production through water electrolysis will provide an excellent way to supplement the intermittency of renewable energy sources. While alkaline water electrolysis is currently the most mature technology, it has drawbacks of low current density, large footprint, gas crossover, etc. The PEM water electrolysis has potential to replace the alkaline electrolysis. However, expensive catalyst material used in the PEM electrolysis has been the bottleneck of widespread use. In this review, we have reviewed recent efforts to reduce catalyst loading in PEM water electrolysis. In core-shell nanostructures, the precious metal catalyst forms a shell while heteroatoms form a core. In this way, the catalyst loading can be significantly reduced while maintaining the catalytic activity. In another approach, a corrosion-resistant support is utilized, which provides a stable platform to impregnate precious metal catalyst.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.667-673
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• 2009

This study has carried out to evaluate the performance of single (electrolysis, UV and ultrasonic process) and complex process (Electrolysis+UV, UV+Ultrasonic and Electrolysis+Ultrasonic) for the purpose of disinfection of Escherichia coli in water. The order of disinfection performance for E. coli in single process lie in: Electrolysis ${\fallingdotseq}$ UV >> ultrasonic process. OH radical was not produced in single disinfection process. Among the three kinds of complex process, disinfection performance of the Electrolysis+UV was higher than that of the other process (UV+Ultrasonic and Electrolysis+Ultrasonic). It demonstrated a synergetic effect between the UV and electrolysis. When the use of $Na_2SO_4$ as electrolyte instead of NaCl, current increase or more reaction time was needed for the complete disinfection. The disinfection performance of pre-electrolysis (20 W, 30sec) and post-UV (10 W, 30 sec) was higher than that of the simultaneous electrolysis+UV process at same electric power (30 W, 30 second).

• Journal of Environmental Science International
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• v.30 no.7
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• pp.597-604
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• 2021

The International Maritime Organization (IMO) ballast water management agreement (International Convention for the Control and Management of Ship's Ballast Water and Sediments) came into force on September 8, 2017. This study evaluated the disinfection performance of electrolysis, UV treatment, and electrolysis + UV combined, to improve the treatment of zooplankton (size ≥ 50 ㎛), which is expected to strengthen the standards for biodegradation efficiency. Among the methods used, the disinfection time leading to 100% death was in the order: electrolysis > electrolysis + UV > UV process. For the same level of disinfection performance, the amount of electricity required for the electrolysis, UV, and electrolysis + UV processes were 1,300 W.s, 8,400 W.S, and 4,500 W.s, respectively. The combination of electrolysis + UV process for inactivation of zooplankton in ballast water did not show a synergic effect owing to the slow disinfection time and high power consumption.

• Prospectives of Industrial Chemistry
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• v.24 no.4
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• pp.1-21
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• 2021

화석연료의 과도한 사용으로 유발된 기후변화 문제를 해결하기 위해 대체에너지의 개발에 대한 관심이 높아지고 있는 가운데 재생가능하며 친환경적인 수소에너지가 실현가능한 궁극적 대안으로 주목받고 있다. 다양한 수소 생산 기술 중 물의 전기분해를 이용한 수전해 기술은 온실가스와 같은 오염물질을 배출하지 않으며 재생에너지와 연계하여 미이용 전력을 대용량 장주기로 저장할 수 있다는 장점이 있다. 수전해 장치는 수소와 산소를 발생하는 전극과 기체의 섞임을 방지하고 이온을 전달하는 분리막으로 구성되며 그 중 분리막은 수전해 장치의 효율과 안정성을 결정짓는 핵심 부품이다. 본 총설에서는 수전해 기술 중 저온 수전해에 해당하는 알칼라인 수전해(alkaline water electrolysis), 고분자전해질막 수전해(polymer electrolyte membrane water electrolysis)와 음이온교환막 수전해(anion exchange membrane water electrolysis)에 사용되는 분리막에 대한 특성을 분석하고 최근 연구 동향에 대해서 다루고자 한다.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.4
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• pp.324-332
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• 2004

According to the rapid depletion of the fossil fuels, the electricity and hydrogen will gradually take charge of the future energy supply. Especially, in order to control the supply and demand of electricity, energy storage medium is necessary and this could be solved by the combination of water electrolysis and fuel cell. Although electricity can be generated from such alternative energies as hydropower, nuclear, solar, and wind-power resources, alternative energy storage medium is also required since regenerative energies, solar and wind-powers, are intermittent energy resources. In this regard, hydrogen production from water electrolysis was recognized as a superb method for electricity storage. In this work, the current development and economic status of alkaline, solid polymer, and high temperature electrolysis were reviewed, and then the practical use of water electrolysis technology were discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.1
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• pp.1-10
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• 2021

Water electrolysis technology, which generates hydrogen using renewable energy resources, has recently attracted great attention. Especially, the polymer electrolyte membrane water electrolysis system has several advantages over other water electrolysis technologies, such as high efficiency, low operating temperature, and optimal operating point. Since research that analyzes performance characteristics using test bench have high cost and long test time, however, model based approach is very important. Therefore, in this study, a system model for water electrolysis dynamics of a polymer electrolyte membrane was developed based on MATLAB/Simulink®. The water electrolysis system developed in this study can take into account the heat and mass transfer characteristics in the cell with the load variation. In particular, the performance of the system according to the stack temperature control can be analyzed and evaluated. As a result, the developed water electrolysis system can analyze water pump dynamics and hydrogen generation according to temperature dynamics by reflecting the dynamics of temperature.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.389-398
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• 2019

Hydrogen energy is not only a solution to climate change problems caused by the use of fossil fuels, but also as an alternative source for the industrial power generation and automotive fuel. Among hydrogen production methods, electrolysis of water is considered to be one of the most efficient and practical methods. Compared to that of the fossil fuel production method, the method of producing hydrogen directly from water has no emission of methane and carbon dioxide, which are regarded as global environmental pollutants. In this paper, the alkaline water electrolysis (AWE) and polymer electrolyte membrane water electrolysis (PEMWE), which are one of the hydrogen production methods, were discussed. Recent research trends of hydrocarbon electrolyte membranes and the crossover phenomenon of electrolyte membranes were also described.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.617-620
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• 1999

To reduce the consumption of chemicals and ultra pure water(UPW) in cleaning process used in device manufacturing, we proposed wet processes that use electrolytic ionized water(EIW), which is generated by electrolysis of a diluted electrolyte solution or UPW and systemically investicate the EIW\`s characteristics. EIW\`s pH values are increased in cathode chamber and decreased in anode chamber according to the electrolysis time and its varied ratio is reduced with time increasement. The variation of pH and ORP is increased accordin to the applied voltage until critical voltage. But more than that voltage, the variation is decreased because of ion\`s scattering effect. When electrolyte is added, the effects of electrolysis is increased because electrolyte acts as catalyst. But when the density of electrolyte is increased more than critical value, ion\`s flowage is obstructed and the effects of electrolysis is decreased.

• Membrane Journal
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• v.27 no.6
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• pp.477-486
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• 2017

Hydrogen is one of energy storage systems, which could be transfer from electric energy to chemical energy or from chemical energy to electric energy, and is as an energy carrier. Water electrolysis is being investigating as one of the hydrogen production methods. Recently, water electrolysis receive attention for the element technology in PTG (power to gas) and PTL (power to liquid) system. In this paper, it was explained the principle and type for the water electrolysis, and recent research review for the alkaline water electrolysis.