• Journal of Hydrogen and New Energy
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• v.33 no.6
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• pp.723-732
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• 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℃.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1544-1546
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• 1999

The fabrication process for ceramic fuel cell with a large electrode area was investigated. A cofired cell of two layer, electrolyte/anode, yielded a power of $200mW/cm^2$. Its performance loss was mainly due to iR drop in the anode side. The performance of the cofired of three layer. cathode/electrolyte/ anode, was much lower than that of two layer, which resulted from the large iR drop and overvoltage at the cathode side. Also a flat cell with a large area of $7.7{\times}10.8cm^2$ was fabricated successfully and tested using ceramic and metallic interconnectors. The large cell with metallic interconnectror showed a good performance of 0.6 V, 4.5 A.

• Electrical & Electronic Materials
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• v.10 no.6
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• pp.528-532
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• 1997

The research and development for the solid oxide fuel cell have been promoted rapidly and extensively in recent years, because of their high efficiency and future potential. Therefore this paper describes the manufacturing method and characteristics of anode electrode for SOFC, by the way, Ni-YSZ materials are used as anode of SOFC widely. So in this experiments, we investigated the optimum content of Ni, by testing expansion coefficient, impedance characteristics, overvoltage. As a result, the performance of Ni-YSZ anode(40vol%) was better excellent than the others.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.252.1-252.1
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• 2010

These studies convert to useful electricity from swine wastewater and to treat this wastewater. In order to operate the microbial fuel cell(MFC) for the swine wastewater, the anode volume of MFCs was scaled up with 5L in the vacant condition. Graphite felts and low-priced mesh stainless-less as electrode had mixed up and packed into the anode compartment. The meshed stainless-less electrode could also be acted the collector of electron produced by microorganisms in anode. For a cathode compartment, graphite felt loaded Pt/C catalyst was used. Graphite felt electrode embedded in the anode compartment was punched holds at regular intervals to prevent occurred the channeling phenomenon. The sources of seeding on microbial fuel cell was used a mixture of swine wastewater and anaerobic digestion sludge(1:1). It was enriched within 6 days. Swine wastewater was fed with 53.26 ml/min flow rate. The MFCs produced a current of about 17 mA stably used swine wastewater with $3,167{\pm}80mg/L$. The maximum power density and current density was 680 $mW/m^3$ and 3,770 $mA/m^3$, respectively. From these results it is showed that treatment of swine wastewater synchronizes with electricity generation using modified low priced microbial fuel cell.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.38-57
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• 2021

The different weight ratios of Pd to Pt, i.e., 16:4, 10:10, 4:16 in Pd-Pt/C and Pd (20 wt. %) /C electrocatalysts with low metal loading were synthesized for glycerol electrooxidation in an air breathing microfluidic fuel cell (MFC). The cell performance on Pd-Pt (16:4)/C anode electrocatalyst was found best among all the electrocatalysts tested. The single cell when tested at a temperature of 35℃ using Pd-Pt (16:4)/C, showed maximum open circuit voltage (OCV) of 0.70 V and maximum power density of 2.77 mW/㎠ at a current density of 7.71 mA/㎠. The power density increased 1.45 times when cell temperature was raised from 35℃ to 75℃. The maximum OCV of 0.78 V and the maximum power density of 4.03 mW/㎠ at a current density of 10.47 mA/㎠ were observed at the temperature of 75℃. The results of CV substantiate the single cell performance for various operating parameters.

• Journal of the Korean Society of Combustion
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• v.15 no.3
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• pp.8-14
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• 2010

Fuel processing systems which convert fuel into rich gas (such as stream reforming, partial oxidation, autothermal reforming) need high temperature environment ($600{\sim}1,000^{\circ}$). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1~5 kW fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas, mixture of natural gas & anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural gas & anode off gas as reformer fuel in the porous ceramic burner. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity. In particular, the blue surface flame is found to be very stable at a very lean equivalence ratio at heat capacity and different fuels. The exhausted NOx and CO measurement shows that the blue surface flame represents the lowest NOx and CO emissions since it remains very stable at a lean equivalence ratio.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.82.2-82.2
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• 2011

A channel design which is closely related with the mass transport overpotential is one of the most important procedures to optimize the whole fuel cell performance. In this study, three dimensional results of a numerical study for gas distribution in channels of a molten carbonate fuel cell (MCFC) unit cell for a 1kW class stack was presented. The relationship between the fuel and air distribution in the anode and cathode channels of the unit cell and the electric performance was observed. A charge balance model in the electrodes and the electrolyte coupled with a heat transfer model and a fluid flow model in the porous electrodes and the channels was solved for the mass, momentum, energy, species and charge conservation. The electronic and ionic charge balance in the anode and cathode current feeders, the electrolyte and GDEs were solved for using Ohm's law, while Butler-Volmer charge transfer kinetics described the charge transfer current density. The material transport was described by the diffusion and convection equations and Navier-Stokes equations govern the flow in the open channel. It was assumed that heat is produced by the electrochemical reactions and joule heating due to the electrical currents.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2539-2545
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• 2012

In the present study, we suggest a new way to reactivate performance of direct formic acid fuel cell (DFAFC) and explain its mechanism by employing electrochemical analyses like chronoamperometry (CA) and cyclic voltammogram (CV). For the evaluation of DFAFC performance, palladium (Pd) and platinum (Pt) are used as anode and cathode catalysts, respectively, and are applied to a Nafion membrane by catalyst-coated membrane spraying. After long DFAFC operation performed at 0.2 and 0.4 V and then CV test, DFAFC performance is better than its initial performance. It is attributed to dissolution of anode Pd into $Pd^{2+}$. By characterizations like TEM, Z-potential, CV and electrochemical impedance spectroscopy, it is evaluated that such dissolved $Pd^{2+}$ ions lead to (1) increase in the electrochemically active surface by reduction in Pd particle size and its improved redistribution and (2) increment in the total oxidation charge by fast reaction rate of the Pd dissolution reaction.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.883-888
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• 2012

Anode electrode is one of the most important factors in microbial fuel cell (MFC). This study was conducted to investigate the effects of mediator as methylene blue (MB) and electrode surface area on the power density of MFC with sponge and carbon nano tube (CNT) electrode (SC). The SC electrode with MB (MC) showed the maximum power density increased from 74.0 $mW/m^2$ to 143.1 $mW/m^2$. The grid shaped sponge and CNT (GSC) electrode showed the maximum power density of 209.2 $mW/m^2$ due to the increase of surface area from 88.0 to 152.0 $cm^2$. The GSC electrode with MB (GMC) revealed the maximum power density of 384.9 $mW/m^2$ which was 5.2 times higher than that obtained from the MFC with SC. Therefore MB and increase of surface area led to enhance the performance of microbial fuel cell such as power density.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.248-251
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• 2008

The objective of this study is to select fuel/air feeders for reliable operation of BOP(Balance of Plant) system for a DMFC (direct methanol fuel cell). A 42-cell 50W DMFC stack is considered for performance comparison of selected fuel pumps and air blowers. The present stack has two serpentine anode channels with depth of 1.2 mm and rib of 1 mm and one serpentine cathode channel with depth of 1.5 mm and rib of 1 mm. The pressure drop through the stack is estimated in advance by utilizing the pre-existing loss coefficients data for various flow configurations. Then the operating points of feeders are determined at the balance point of the flow impedance curves for the channels in the DMFC stack and the selected pump and blower performance curves. After estimating the operating flow rates in the anode and cathode channels, the flow measurement with the selected feeders is performed for the comparison with the estimated flow rates. The measured results show that the discrepancy between the estimation and the measurement for the cathode is about 26%, about 3% for the anode