• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.659-666
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• 2019

Proton exchange membrane fuel cells (PEMFCs) generate electricity by electrochemical reactions of hydrogen and oxygen. PEMFCs are expected to alternate electric power generator using fossil fuels with various advantages of high power density, low operating temperature, and environmental-friendly products. PEMFCs have widely been used in a number of applications such as fuel cell vehicles (FCVs) and stationary fuel cell systems. However, there are remaining technical issues, particularly the long-term durability of each part of fuel cells. Degradation of a carbon supported-platinum catalyst in the anode and cathode follows various mechanistic origins in different fuel cell operating conditions, and thus accelerated stress test (AST) is suggested to evaluate the durability of electrocatalyst. In this article, comparable protocols of the AST durability test are intensively explained.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.493-499
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• 2010

Steam reforming (SR) of glycerol, a main by-product of manufacturing process of bio-diesel, for the production of hydrogen was investigated over the Ni-based catalysts. The Ni-based catalysts were prepared by an impregnation method, and characterized by $N_2$ physisorption, CO chemisorption, XRD and TEM techniques. It was found that the Ni/${\gamma}-Al_2O_3$ catalyst showed higher conversion and catalytic stability for the carbon formation than the other catalysts in the steam reforming of glycerol under the tested conditions. The results suggest that the steam reforming of glycerol over modified Ni/${\gamma}-Al_2O_3$ catalyst minimized carbon formation can be applied in hydrogen station for fuel-cell powered vehicles and fuel processor for stationary and portable fuel cells.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.71.2-71.2
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• 2012

There are rising demands for developing more efficient energy materials to stem the depletion of fossil fuels, which have prompted significant research efforts on proton exchange fuel cells (PEFCs) and lithium ion batteries (LIBs). To date, both PEFCs and LIBs are being widely developed to power small electronics, however, their utilization to medium-large sized electric power resources such as vehicle and stationary energy storage systems still appears distant. These technologies increasingly rely upon polymer electrolyte membranes (PEMs) that transport ions from the anode to the cathode to balance the flow of electrons in an external circuit, and therefore play a central role in determining the efficiency of the devices; as ion transport is a kinetic bottleneck compared to electrical conductivity, enormous efforts have been devoted to improving the transport properties of PEMs. In present study, we carried out an in-depth analysis of the morphology effects on transport properties of PEMs. How parameters such as self-assembled nanostructures, domain sizes, and domain orientations affect conductivities of PEMs will be presented.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.3
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• pp.193-200
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• 2010

Anode off-gas of high temperature fuel cell still contains combustible components such as hydrogen, carbon monoxide and hydrocarbon. In this study, a catalytic combustor has been applied to the high temperature fuel cell so that the combustion of anode-off gas can be boosted up. Since the performance of catalytic combustor directly depends on the combustion catalyst, this study is designed to perform the experimental investigation on the combustion characteristics of the three commercial catalysts with a different composition. Screening tests with three catalysts are preceded before the performance examination since it is necessary to determine the most suitable catalyst for design configuration of the catalytic combustor. The performance analysis shows that methane conversion rate strongly depends on gas hourly space velocity (GHSV) as well as inlet gas temperature. Additionally, the GSHV optimization results show that the optimum GHSV will be in the range between 18,000 $hr^{-1}$ and 36,000 $hr^{-1}$. It is also shown that the minimum inlet temperature of catalytic reaction of methane is from $100^{\circ}C$ to $150^{\circ}C$.

• Environmental Engineering Research
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• v.19 no.4
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• pp.363-367
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• 2014

One chambered sediment microbial fuel cell (SMFC) was equipped with Fe, brass (Cu/Zn), Fe/Zn, Cu, Cu/carbon cloth and graphite felt anode. Graphite felt was used as common cathode. The SMFC was membrane-less and mediator-less as well. Order of anodic performance on the basis of power density was Fe/Zn ($6.90Wm^{-2}$) > Fe ($6.03Wm^{-2}$) > Cu/carbon cloth ($2.13Wm^{-2}$) > Cu ($1.13Wm^{-2}$) > brass ($Cu/Zn=0.24Wm^{-2}$) > graphite felt ($0.10Wm^{-2}$). Fe/Zn composite anode have twisted 6.73% more power than Fe alone, Cu/carbon cloth boosted power production by 65%, and brass (Cu/Zn) produced 65% less power than Cu alone. Graphite felt have shown the lowest electricity generation because of its poor galvanic potential. The estuarine sediment served as supplier of oxidants or electron producing microbial flora, which evoked electrons via a complicated direct microbial electron transfer mechanism or making biofilm, respectively. Oxidation reduction was kept to be stationary over time except at the very initial period (mostly for sediment positioning) at anodes. Based on these findings, cost effective and efficient anodic material can be suggested for better SMFC configurations and stimulate towards practical value and application.

• 한국가스학회:학술대회논문집
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• 2006.11a
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• pp.177-182
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• 2006

• Journal of Energy Engineering
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• v.27 no.4
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• pp.1-12
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• 2018

The code and standards related to fuel cells were analyzed to derive the SOFC(Solid Oxide Fuel Cell) stack safety performance evaluation items and evaluation methode. Safety performance evluation of the SOFC stack was tested by quoting derived test items. The stack used in the test is an anode-supported type 2 Cell stack (Active surface area : 220cm) manufactured by MICO Inc, and SOFC stack safety performance evaluation system used for the test is self-manufactured. We conducted a leakage test, current voltage characteristic test, rated output test, and power response characteristics test. In the safety performance evaluation test, the stack showed no gas leakage, the maximum output and rated output was recorded to 65.6 W(1.41 V, 46.5 A, $422mA/cm^2$), 62.3 W(1.57 V, 40 A, $363mA/cm^2$). In the power response characteristics test verified that the output is kept stable within two seconds. At the maximum load (40 A) and the minimum load (8 A), the output was recorded 62 W and 16W in $750^{\circ}C$. This study will contribute to the universalization and to provide much safe environment of operating the solid oxide fuel cell system.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.973-977
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• 2013

These studies were attempted to investigate the change of microbial community of anode of microbial fuel cell using swine wastewater in the enrichment step with the lapse of time. Microbial fuel cells enriched by a 1 : 1 mixture of anaerobic digestive juices of the sewage treatment plant and livestock wastewater. Enrichment culture step was divided into three stages to indentify the microorganisms. It was separated by each lag phase, exponential phase, and stationary phase. These steps were determined by the change of the current value. The current after enrichment was generated about $0.84{\pm}0.06mA$. We were cut out the different 17 bands in the DGGE fingerprint gel to do sequencing. The bands which the concentration was increasing or newly appearing with the lapse of time were included for this study. In the lag and exponential phase, Clostridium, Rhodocyclaceae, Bacteriodetes, and Uncultured bacterium etc. were detected. There were in the stationary phase Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae and uncultured bacterium etc. Geobactor among microorganisms detected in this study is known as the Electrochemically active microorganisms. It may include electrochemically active microorganisms to be considered as electrical activity microorganisms.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.37-43
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• 2008

The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.107-109
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• 2006

This study focuses on a determination of amount of Pt in the Pt/C for catalysts of polymer electrolyte membrane fuel cells (PEMFC). PEMFC offer low weight and high power density and being considered for automotive and stationary power applications. The PEMFC performance is influenced by several factors, including catalysts and structure of electrode and membrane type. Catalyst of electrode is important factor for PEMFC. One of the obstacles prevent ing polymer electrolyte membrane fuel cells from commercialization is the high cost of noble metals to be used as catalyst, such as platinum To effectively use these metals, they have to be will dispersed to small particles on conductive carbon supports. The optimal amount of Pt in Pt/C for cathode catalyst was investigated by using polarization curves in single cell with $H_2/O_2$ operation.