• 한국수소및신에너지학회논문집
• /
• 제26권3호
• /
• pp.206-211
• /
• 2015

For the hydrogen production, Gas Lab and Gnc make alkaline watrer electrolyzer and found optimized condition of experimental parameters of cell material and operating procedures. For the commercial production, we saved electric power consumption and caloric based efficiency with over 70%. Used cell pressures are 10 bar, 30 bar and consumed electricity is $4,000A/m^2$, 4.19 kW ($T=100^{\circ}C$) at 10 bar. Another data is $2,000A/m^2$, 3.92 kW ($T=95^{\circ}C$) at 30 bar. Applied voltage is 1.75 V ($100^{\circ}C$, 10 bar), 1.64 V ($95^{\circ}C$, 10 bar), 1.81 V ($85^{\circ}C$, 30 bar), 1.76 V ($95^{\circ}C$, 30 bar). As cell temperature increase, applied voltage has been decreased and current has been increased. The concentration of KOH solution is 30 weight %.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.524-527
• /
• 2000

An electroenzymatic system to oxidize veratryl alcohol of on electrodes with in-situ generated hydrogen peroxide was studied. We investigated hydrogen peroxide generation, current efficiency, and veratryl alcohol oxidation in the electrode system at various conditions. The reaction rates of veratryl alcohol oxidation were compared in an electrochemical, an electroenzymatic, and an usual biochemical systems to prove the concept of electroenzymatic oxidation.

• 한국표면공학회지
• /
• 제56권6호
• /
• pp.412-419
• /
• 2023

Anion exchange membrane electrolysis is considered a promising next-generation hydrogen production technology that can produce low-cost, clean hydrogen. However, anion exchange membrane electrolysis technology is in its early stages of development and requires intensive research on electrodes, which are a key component of the catalyst-system interface. In this study, we optimized the pressure conditions of the hot-pressing process to manufacture cobalt oxide electrodes for the development of a high uniformity and high adhesion electrode production process for the oxygen evolution reaction. As the pressure increased, the reduction of pores within the electrode and increased densification of catalytic particles led to the formation of a uniform electrode surface. The cobalt oxide electrode optimized for pressure conditions exhibited improved catalytic activity and durability. The optimized electrode was used as the anode in an AEMWE single cell, exhibiting a current density of 1.53 A cm^-2 at a cell voltage of 1.85 V. In a durability test conducted for 100 h at a constant current density of 500 mA cm^-2, it demonstrated excellent durability with a low degradation rate of 15.9 mV kh^-1, maintaining 99% of its initial performance.

• 한국군사과학기술학회지
• /
• 제20권4호
• /
• pp.491-496
• /
• 2017

The hydrogen($H_2$) is promising energy carrier of renewable energy in the microgrid system such as small village and military base due to its high energy density, pure emission and convenient transportation. $H_2$ can be generated by photocatalytic water splitting, gasification of biomass and water electrolysis driven by solar cell or wind turbine. Solid oxide electrolysis cells(SOECs) are the most efficient way to mass production due to high operating temperature improving the electrode kinetics and reducing the electrolyte resistance. The SOECs are consist of nickel-yttria stabilized zirconia(NiO-YSZ) fuel electrode / YSZ electrolyte / lanthanum strontium manganite-YSZ(LSM-YSZ) air electrode due to similarity to Solid Oxide Fuel Cells(SOFCs). The Ni-YSZ most widely used fuel electrode shows several problems at SOEC mode such as degradation of the fuel electrode because of Ni particle's redox reaction and agglomeration. Therefore Ni-YSZ need to be replaced to an alternative fuel electrode material. In this study, We studied on the Double perovskite $PrBrMnO_{5+{\delta}}$(PBMO) due to its high electric conductivity, catalytic activity and electrochemical stability. PBMO was impregnated into the scaffold electrolyte $La_{0.8}Sr_{0.2}Ga_{0.85}Mg_{0.15}O_{3-{\delta}}$(LSGM) to be synthesized at low temperature for avoiding secondary phase generated when it exposed to high temperature. The Half cell test was conducted at SOECs and SOFCs modes.

• 한국수소및신에너지학회논문집
• /
• 제31권6호
• /
• pp.530-545
• /
• 2020

This paper reviews and summarizes the fuel-cell-related studies those have been recently published in major Korean Citation Index journals, aiming at analyzing the research trend in fuel cell technologies. Six major journals are selected for the literature survey; 57 papers are chosen for the detailed analysis through a screening examination on the total 1,040 papers published during between 2018 and 2020. Papers are classified into six technical categories, such as i) electrode, ii) electrolyte, iii) bipolar plate and stack, iv) fuel cell system, v) balance of plant, and vi) diagnosis-related studies, and summarized by the experts in the relevant area. Through this paper, we provide a comprehensive review on the recent trends and progress in fuel-cell-related research work in Korea.

• 한국수소및신에너지학회논문집
• /
• 제33권6호
• /
• pp.723-732
• /
• 2022

Cracking ammonia inside solid oxide fuel cell (SOFC) stack is a compact and simple way. To prevent sharp temperature fluctuation and increase cell efficiency, the decomposition reaction should be spread on whole cell area. This leading to a question that, how does anode thickness affect the conversion rate of ammonia and the cell voltage? Since the 0D model of SOFC is useful for system level simulation, how accurate is it to use equilibrium solver for internal ammonia cracking reaction? The 1D model of ammonia fed SOFC was used to simulate the diffusion and reaction of ammonia inside the anode electrode, then the partial pressure of hydrogen and steam at triple phase boundary was used for cell voltage calculation. The result shows that, the ammonia conversion rate increases and reaches saturated value as anode thickness increase, and the saturated thickness is bigger for lower operating temperature. The similar cell voltage between 1D and 0D models can be reached with NH₃ conversion rate above 90%. The 0D model and 1D model of SOFC showed similar conversion rate at temperature over 750℃.

• 한국수소및신에너지학회논문집
• /
• 제30권4호
• /
• pp.303-311
• /
• 2019

Reversible solid oxide fuel cell (RSOFC) has become a prospective device for energy storage and hydrogen production. Many studies have been conducted around the world focusing on system efficiency improvement and realization. The system should have not only high efficiency but also a certain level of simplicity for stable operation. External waste steam utilization was proved to remarkably increase the efficiency at solid oxide electrolysis system. In this study, RSOFC system coupled with waste steam was proposed and optimized in term of simplicity and efficiency. Ejector for fuel recirculation is selected due to its simple design and high stability. Three system configurations using ejector for fuel recirculation were investigated for performance of design condition. In parametric study, the system efficiencies at different current density were analyzed. The system configurations were simulated using validated lumped model in EBSILON(R) program. The system components, balance of plants, were designed to work in both electrolysis and fuel cell modes, and their off-design characteristics were taken into account. The base case calculation shows that, the system with suction pump results in slightly lower efficiency but stack can be operated more stable with same inlet pressure of fuel and air electrode.

• 한국수소및신에너지학회논문집
• /
• 제14권1호
• /
• pp.35-45
• /
• 2003

Polymer electrolyte fuel cells(PEFC) have been considered to be a suitable candidate for residential, portable and mobile applications, due to their high efficiency and power density, even at low operating temperature. KIER developed a 5kW class PEFC system for residential application and operated the system for over 1,000 hours. To develop a 5kW PEFC system, performance of a cell was improved through successive tests of single cell of small and large area. Fabrication of three 2,5 kW class stacks, design and fabrication of natural gas reformer, design of auxiliary equipments such as DC/DC converter, DC/AC inverter and humidifying units were carried out along with integration of components, operation and evaluation of total system. During the development period from 1999 to 2001, MEA(membrane electrode assembly) fabrication technologies, design and fabrication technologies for separators, stacking technologies and so on were developed, thereby providing basis for developing stacks of higher efficiency and power density in the future. Experience of development of natural gas reformer opened possibilities to use various kinds of fuels. Main results obtained from the development of a 5kW class PEFC system for residential application are summarized.

• 한국수소및신에너지학회논문집
• /
• 제18권3호
• /
• pp.244-249
• /
• 2007

The present work considers the concept of enzymatic photoelectrochemical generation of hydrogen through water splitting using a Xe lamp as a source of light. A solar cell was applied to the system in order to shift the level of electrochemical energy of the system, resulting in the rate of hydrogen production at $43\;{\mu}mol/(cm^2{\times}hr)$ in cathodic compartment with an anodized tubular $TiO_2$ electrode(ATTE, $5^{\circ}C$/1hr in 0.5 wt% HF-$650^{\circ}C$/5hr). The trend of the rate of hydrogen production, for the ATTEs with different annealing temperature from $350^{\circ}C$ to $850^{\circ}C$, fairly well coincided with the photoelectrical properties measured by potentiostat. The actual chemical bias through imposition of two electrolytes of different pHs between anode(13.68) and cathode(7.5) was 0.24eV.

• 멤브레인
• /
• 제31권2호
• /
• pp.133-144
• /
• 2021

알칼리 수전해 시스템은 다양한 수소 생산 공정 중에서 가장 온실가스 발생량이 적은 그린 수소를 생산하는 방식 중 가장 오래된 기술이다. 알칼리 수전해 시스템은 알칼리 조건에서 사용되며, 고분자 전해질막 수전해와는 다르게 니켈, 코발트, 은 등의 안정한 전이금속을 전극촉매로 사용할 수 있다. 이 시스템은 가격이 저렴하고 대용량화가 용이하다는 장점을 가지고 있다. 이러한 장점으로 알칼리 수전해 시스템은 20세기 초부터 MW급 수소발생장치에 적용되어 왔으며 현재 20여 개의 제조업체에서 상용제품을 판매하고 있는 안정화된 기술이다. 본 논문에서는 알칼라인 수전해의 기본원리 및 사용되는 촉매, 전극, 격막 등에 대해 알아보고 그 중 핵심소재인 격막의 연구개발 동향에 대해 살펴보고자 한다.