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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean hydrogen and new energy society
Journal Basic Information
Journal DOI :
The Korean Hydrogen and New Energy Society
Editor in Chief :
Volume & Issues
Volume 24, Issue 6 - Dec 2013
Volume 24, Issue 5 - Oct 2013
Volume 24, Issue 4 - Aug 2013
Volume 24, Issue 3 - Jun 2013
Volume 24, Issue 2 - Apr 2013
Volume 24, Issue 1 - Feb 2013
Selecting the target year
Start-up Strategy for the Successful Operation of Continuous Fermentative Hydrogen Production
Lee, Chang-Kyu ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 99~106
DOI : 10.7316/KHNES.2013.24.2.099
The variations of performance and metabolites at an early stage were investigated for the successful start-up technology in continuous fermentative hydrogen production. Unsuccessful start-up was observed when the operation mode was changed from batch to continuous mode after the yield was reached to 0.5 mol
by batch mode.
production continued till 12 hours accompanied by butyrate production, but did not last with propionate production increase. It was suspected that the failure was due to the regrowth of propionic acid bacteria during batch mode which were inhibited by heat-shock but not completely killed. Thus, successful start-up was tried by early switchover from batch to continuous operation; continuous operation was started after the
yield was reached to 0.2 mol
by batch mode. Although
production rate decreased at an early stage, stable
yield of 0.8 mol
was achieved after 10 days by lowering down propionate production. And it was also concluded that the reason for
production decrease at an early stage was due to alcohol production by self detoxification mechanism against VFAs accumulation.
CdSe Sensitized ZnO Nanorods on FTO Glass for Hydrogen Production under Visible Light Irradiation
Kim, Hyun ; Yang, Bee Lyong ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 107~112
DOI : 10.7316/KHNES.2013.24.2.107
The ZnO is able to produce hydrogen from water however it can only absorb ultraviolet region due to its 3.37eV of wide band gap. Therefore efficiency of solar hydrogen production is low. In this work we report investigation results of improved visible light photo-catalytic properties of CdSe quantum dots(QDs) sensitized ZnO nanorod heterostructures. Hydrothermally vertically grown ZnO nanorod arrays on FTO glass were sensitized with CdSe by using SILAR(successive ionic layer adsorption and reaction) method. Morphology of grown ZnO and CdSe sensitized ZnO nanorods had been investigated by FE-SEM that shows length of
, diameter of 120~150nm nanorod respectively. Photocatalytic measurements revealed that heterostructured samples show improved photocurrent density under the visible light illumination. Improved visible light performance of the heterostructures is resulting from narrow band gap of the CdSe and its favorable conduction band positions relative to potentials of ZnO band and water redox reaction.
Numerical Analysis of Steam-methane Reforming Reaction for Hydrogen Generation using Catalytic Combustion
Lee, Jeongseop ; Lee, Kanghoon ; Yu, Sangseok ; Ahn, Kookyoung ; Kang, Sanggyu ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 113~120
DOI : 10.7316/KHNES.2013.24.2.113
A steam reformer is a chemical reactor to produce high purity hydrogen from fossil fuel. In the steam reformer, since endothermic steam reforming is heated by exothermic combustion of fossil fuel, the heat transfer between two reaction zones dominates conversion of fossil fuel to hydrogen. Steam Reforming is complex chemical reaction, mass and heat transfer due to the exothermic methane/air combustion reaction and the endothermic steam reforming reaction. Typically, a steam reformer employs burner to supply appropriate heat for endothermic steam reforming reaction which reduces system efficiency. In this study, the heat of steam reforming reaction is provided by anode-off gas combustion of stationary fuel cell. This paper presents a optimization of heat transfer effect and average temperature of cross-section using two-dimensional models of a coaxial cylindrical reactor, and analysis three-dimensional models of a coaxial cylindrical steam reformer with chemical reaction. Numerical analysis needs to dominant chemical reaction that are assumed as a Steam Reforming (SR) reaction, a Water-Gas Shift (WGS) reaction, and a Direct Steam Reforming(DSR) reaction. The major parameters of analysis are temperature, fuel conversion and heat flux in the coaxial reactor.
Hydrogen Brittleness on Welding Part for SDS Bottles
Kim, Raymund K.I. ; Jung, Seok ; Kang, Hyungoo ; Chang, Minho ; Yun, Seihun ; Hong, Tae-Whan ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 121~127
DOI : 10.7316/KHNES.2013.24.2.121
Tritium was attracted with high energy source in neutron fusion energy systems. A number of research was performed in tritium storage materials. The Korea was raised storage and delivery systems (SDS) of international thermonuclear experimental reactor (ITER) research. However, bottles of SDS would be important because of stability. The bottles have a welding zone, this zone will be vulnerable to hydrogen embrittlement. This zone have a high thermodynamic energy and heat deterioration. Therefore bottles were studied about hydrogen embrittlement to retain stability. The heat treatment of hydrogen was carried under pressure-composition-temperature (PCT) apparatus because of checking at real time. And then, mechanical properties were evaluated by tensile test and hardness test. In results of this study, hydrogen atmosphere condition is very important by tensile test and kinetics test. The samples were evaluated, that is more weak hydrogen pressure, increasing temperature and time. This results could be useful in SDS bottle designs.
Rapid Cooling Performance Evaluation of a ZrCo bed for a Hydrogen Isotope Storage
Lee, Jungmin ; Park, Jongchul ; Koo, Daeseo ; Chung, Dongyou ; Yun, Sei-Hun ; paek, Seungwoo ; Chung, Hongsuk ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 128~135
DOI : 10.7316/KHNES.2013.24.2.128
The nuclear fuel cycle plant is composed of various subsystems such as a fuel storage and delivery system (SDS), a tokamak exhaust processing system, a hydrogen isotope separation system, and a tritium plant analytical system. Korea is sharing in the construction of the International Thermonuclear Experimental Reactor (ITER) fuel cycle plant with the EU, Japan, and the US, and is responsible for the development and supply of the SDS. Hydrogen isotopes are the main fuel for nuclear fusion reactors. Metal hydrides offer a safe and convenient method for hydrogen isotope storage. The storage of hydrogen isotopes is carried out by absorption and desorption in a metal hydride bed. These reactions require heat removal and supply respectively. Accordingly, the rapid storage and delivery of hydrogen isotopes are enabled by a rapid cooling and heating of the metal hydride bed. In this study, we designed and manufactured a vertical-type hydrogen isotope storage bed, which is used to enhance the cooling performance. We present the experimental details of the cooling performances of the bed using various cooling parameters. We also present the modeling results to estimate the heat transport phenomena. We compared the cooling performance of the bed by testing different cooling modes, such as an isolation mode, a natural convection mode, and an outer jacket helium circulation mode. We found that helium circulation mode is the most effective which was confirmed in our model calculations. Thus we can expect a more efficient bed design by employing a forced helium circulation method for new beds.
A Study on the Application of the Lean Boosting in a Hydrogen-fueled Engine with the SI and the External Mixture
Lee, Kwangju ; Lee, Jonggoo ; Lee, Jongtai ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 136~141
DOI : 10.7316/KHNES.2013.24.2.136
In order to achieve simultaneously the ultra-low NOx, the high power and the high efficiency in a hydrogen-fueled engine with SI and the external mixture, the effects of low temperature combustion, performance and exhaust are compared and analyzed by the application of the lean boosting. As the results, the decrease rate of the high temperature in the hydrogen is less decreased than the other fuels by high constant-volume specific heat. However, when the conditions of 1.7bar and
are reached by the lean boosting, the maximum gas temperature of hydrogen is decreased under the temperature of NOx formation and it is possible to stabilize combustion below 2% of COVimep. Also, at that condition, it is feasible to achieve simultaneously NOx-free and the power of gasoline level. Therefore, it is found that the lean boosting is useful in the hydrogen-fueled engine.
Synthesisand Electrochemical Behaviors of Hybrid Carbon (ACF/Graphene) as Supports by Microwaves-irradiation Method for Polymer Exchange Membrane Fuel Cells (PEMFC)
Cho, Yongil ; Jeon, Yukwon ; Park, Dae-Hwan ; Juon, So-Me ; Kim, Tae-Eon ; Oh, Kyeongseok ; Shul, Yong-Gun ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 142~149
DOI : 10.7316/KHNES.2013.24.2.142
Carbon materials are mainly used as catalyst supports for polymer exchange membrane fuel cell (PEMFC). Catalyst supports are required specific characteristics of the carbon materials, such as large surface area and high electrical conductivity. Attempted were to improve electrical conductivity and to maintain high surface area of carbon materials using a microwave treatment. Microwave treatment, as a relatively new technique, takes short reaction time and reduce the consumption of the gases used for carbon treatment compared to a traditional heat treatment. Hybrid carbon (ACF/Graphene) as catalyst supports by microwave-irradiation method for PEMFC increase the cell performance because of increased electrical conductivity resulting in triple-phase contact and reduced the interfacial resistance. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray Diffraction (XRD) were employed to analyze carbon materials. The performance of microwave-treated carbon materials was evaluated by measuring current-voltage (I-V) characteristics and electrode impedance.
Effects of Bed Insert Geometry and Shape of WGS Catalysts on CO Conversion in a Fluidized Bed Reactor for SEWGS Process
Ryu, Hojung ; Kim, Hana ; Lee, Dongho ; Bae, Dalhee ; Hwang, Taeksung ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 150~159
DOI : 10.7316/KHNES.2013.24.2.150
To enhance the performance of SEWGS system by holding the WGS catalyst in a SEWGS reactor using bed inserts, effects of insert geometry and shape of WGS catalysts on CO conversion were measured and investigated. Small scale fluidized bed reactor was used as experimental apparatus and WGS catalyst (particle and tablet) and sand were used as bed materials. The parallel wall type and cross type bed inserts were used to hold the WGS catalysts. The CO conversion with steam/CO ratio was determined based on the exit gas analysis. The measured CO conversion using the bed inserts showed high value comparable to physical mixing cases. Moreover, gas flow direction was confirmed by bed pressure drop measurement for each case. Most of input gas flowed through the catalyst side when we charged tablet type catalyst into the bed insert and this can cause low
capture efficiency because the possibility of contact between input gas and
absorbent is low in this case. New bed insert geometry was proposed based on the results from this study to enhance contact between input gas and WGS catalyst and
Characterization of Atmospheric H
as Cathode Materials in Lithium Rechargeable Batteries
Sun, Ho-Jung ; Lee, Jae-Ho ; Jeong, Hyun-Young ; Seok, Dong-Chan ; Jung, Yongho ; Park, Gyungse ; Shim, Joongpyo ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 160~171
DOI : 10.7316/KHNES.2013.24.2.160
powder for cathode materials in lithium rechargeable batteries was treated by atmospheric plasma containing hydrogen to investigate the relationship between charge/discharge performance and physical/chemical changes of materials. Hydrogen plasma at atmosphere pressure was irradiated on the surface of active materials, and the change for their crystal structure, surface morphology, and chemical composition were observed by XRD, SEM-EDS and titration method, respectively. The crystal structure and surface morphology of
plasma-treated powders were not changed but their chemical compositions were slightly varied. For charge/discharge test,
plasma affected initial capacity and rate capability of active materials but continuous cycling was not subject to plasma treatment. Therefore, it was observed that
plasma treatment affected the surface of materials and caused the change of chemical composition.
Effects of Co-solvent on Dendritic Lithium Growth Reaction
Kang, Jihoon ; Jeong, Soonki ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 172~178
DOI : 10.7316/KHNES.2013.24.2.172
This study examined the electrochemical deposition and dissolution of lithium on nickel electrodes in 1 mol
dissolved in propylene carbonate (PC) containing different 1,2-dimethoxyethane (DME) concentrations as a co-solvent. The DME concentration was found to have a significant effect on the reactions occurring at the electrode. The poor cycleability of the electrodes in the pure PC solution was improved considerably by adding small amounts of DME. This results suggested that the dendritic lithium growth could be suppressed by using co-solvents. After hundredth cycling in the 1 M
/PC:DME (67:33) solution, almost no dead lithium has been found from the disassembled cell, resulting from suppression of dendritic lithium growth. Scanning electron microscopy revealed that dendritic lithium formation was greatly affected by the ratio of DME. Raman spectroscopy results suggested that the structure of solvated lithium ions is a crucial important factor in suppressing dendritic lithium formation.
Effects of Charge-discharge Rate on Morphology and Resistance of Surface Film on a Graphite Negative Electrode in an Ethylene Carbonate-based Solution
Jeong, Soonki ; Kim, Pogyom ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 179~185
DOI : 10.7316/KHNES.2013.24.2.179
The behavior of surface film formation was greatly dependent on the speed of potential cycling. In
/ EC + DEC, cyclic voltammetry results showed that the peaks originated from surface film formation on graphite electrode at the high charge-discharge rate was shifted to the lower potentials as the charge-discharge rate decrease. This indicates that surface films with different morphology and thickness were formed by different charge-discharge rate. Transmission electron microscopy (TEM) results indicated that the properties such as thickness and morphology of the surface film were greatly affected by the charge-discharge rate. Electrochemical impedance spectroscopy (EIS) showed that the resistance of surface film was affected by the speed of potential cycling. In addition, the charge transfer resistance was also dependent on the charge-discharge rate indicating that the charge transfer reaction was affected by the nature of surface film. TEM and EIS results suggested that the chemical property as well as the physical property of the surface film was affected by the charge-discharge rate.
Electrochemical Performance of the Solid Oxide Fuel Cell with Different Thicknesses of BSCF-based Cathode
Jeong, Jaewon ; Yoo, Chung-Yul ; Joo, Jong Hoon ; Yu, Ji Haeng ;
Transactions of the Korean hydrogen and new energy society, volume 24, issue 2, 2013, Pages 186~192
DOI : 10.7316/KHNES.2013.24.2.186
In order to reduce the costs and to improve the durability of solid oxide fuel cell (SOFC), the operating temperature should be decreased while the power density is maintained as much as possible. However, lowering the operating temperature increases the cathode interfacial polarization resistances dramatically, limiting the performance of low-temperature SOFC at especially purely electronic conducting cathode. To improve cathode performance at low temperature, the number of reaction sites for the oxygen reduction should be increased by using a mixed ionic and electronic conducting (MIEC) material. In this study, anode-supported fuel cells with two different thicknesses of the MIEC cathode were fabricated and tested at various operating temperatures. The anode supported cell with
-thick BSCFZn-LSCF cathode layer showed much lower polarization resistance than that with
thick cahtode and higher power density especially at low temperature. The effects of cathode layer thickness on the electrochemical performance are discussed with analysis of impedance spectra.