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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 21, Issue 6 - Dec 2010
Volume 21, Issue 5 - Oct 2010
Volume 21, Issue 4 - Aug 2010
Volume 21, Issue 3 - Jun 2010
Volume 21, Issue 2 - Apr 2010
Volume 21, Issue 1 - Feb 2010
Selecting the target year
High Purity Hydrogen Production by Redox Cycle Operation
Jeon, Bup-Ju ; Park, Ji-Hun ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 355~363
High purity hydrogen, 97-99 vol.%, with CO at just ppm levels was obtained in a fixed bed of iron oxide employing the steam-iron cycle operation with reduction at 823K and oxidation in a steam-
mixture at 773K TGA experiments indicated that temperature of the reduction step as well as its duration are important for preventing carbon build-up in iron and the intrusion of
into the hydrogen product. At a reduction temperature of 823K, oxide reduction by
was considerably faster than reduction by CO. If the length of the reduction step exceeds optimal value, low levels of methane gas appeared in the off-gas. Furthermore, with longer durations of the reduction step and CO levels in the reducing gas greater than 10 vol.%, carbidization of the iron and/or carbon deposition in the bed exhibited the increasing pressure drop over the bed, eventually rendering the reactor inoperable. Reduction using a reducing gas containing 10 vol.% CO and a optimal reduction duration gave constant
flow rates and off-gas composition over 10 redox reaction cycles.
Effect of Tip Size and Aspect Ratio on Reforming Performance in a Methane Reformer for Polymer Electrolyte Membrane Fuel Cell (PEMFC)
Seo, Dong-Kyun ; Noh, In-Kyu ; Hwang, Jung-Ho ; Choi, Jong-Kyun ; Shin, Dong-Hoon ; Kim, Hyung-Sik ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 364~374
Design of a reformer consisting of combustion chamber and reforming chamber was investigated for a 1 kW and a 5 kW polymer electrolyte membrane fuel cell (PEMFC), respectively, using the computational fluid dynamics (CFD). First, the 1kW reformer was considered to obtain the reliability of the numerical study. It was modeled, calculated and compared with experimental data. Second, the 5kW reformer was considered for a geometric study. Three tip sizes (35, 40, and 45 mm) and five aspect ratios was selected. It was found that the optimum was at tip sizes of 40 and 45 mm, at aspect ratios of -10% and -20% of the standard length.
Phtocatalytic Activity of the
Thick Film by Aerosol Deposition
Kim, Ji-Ho ; Choi, Duck-Kyun ; Hwang, Kwang-Taek ; Ko, Sang-Min ; Cho, Woo-Seok ; Kim, Jin-Ho ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 375~382
A layered perovskite photocatalysts,
(SBN), was synthesized by the conventional solid-state reaction method and characterized by X-ray diffraction (XRD) and UV-visble spectrophotometry. The results showed that the structure of
is orthorhombic. Diffuse reflectance spectra for calcined and attrition-milled SBN showed the main absorption edges were less 400 nm, that is ultraviolet region. SBN under micron-sized powder was deposited on the
by room temperature powder spray in vacuum process, so called aerosol deposition (AD), and nano-grained
photocatalytic thick film was fabricated. AD-deposited SBN thick films were characterized by XRD, scanning electron microscopy (SEM) and UV-visable spectrophotometry, Moreover, it was found that several nano-sized SBN film by AD process can improve the photocatalytic activity under visable reflectance.
Hydrogen Generation from
Hydrolysis on Co-Ni-P-B/Ni Foam Catalyst
Park, Da-Ill ; Kim, Tae-Gyu ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 383~389
Co-B, Co-P-B, Co-Ni-B and Co-Ni-P-B catalysts supported on Ni foam were prepared using electroless plating in the present study. The surface morphology of the catalysts/Ni foam was observed using SEM and EDS analysis. The Co-Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation due to the uniform formation of catalyst particles on the Ni foam surface. The characteristics of hydrogen generation with Co-Ni-P-B/Ni foam catalyst was investigated at the variety of
and NaOH concentrations. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.
Preparation of Highly Dispersed Ru/
Catalyst for Preferential CO Oxidation
Eom, Hyun-Ji ; Koo, Kee-Young ; Jung, Un-Ho ; Rhee, Young-Woo ; Yoon, Wang-Lai ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 390~397
catalysts are prepared by deposition-precipitation method for the preferential CO oxidation In order to investigate the effect of pH on the Ru dispersion and particle size, the pH of precursor solution is adjusted to between 5.5 and 9.5. 0.5wt% Ru/
catalyst prepared at the pH of 6.5 has high Ru dispersion of 17.9% and small particle size of 7.7nm. In addition, 0.5wt% Ru/
catalyst prepared at the pH 6.5 is easily reduced at low temperatures below
due to high dispersion of
particle and shows high CO conversion over 90% in the wide temperature range between
. Moreover, the deposition-precipitation is a feasible method to improve the Ru dispersion as compared to the impregnation method. The 0.5wt% Ru/
catalyst prepared by deposition-precipitation exhibits higher CO conversion than 0.5wt% Ru/
catalysts prepared by impregnation due to higher metal dispersion and better reducibility at low temperature.
Effects of Additives and Hot-Pressing Conditions on the Surface and Performance of MEAs for PEMFCs
Jang, Hyun-Sook ; Cho, Eun-Ae ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 398~404
Process conditions for MEA fabrications have significant effects on properties and performance of the MEAs for PEMFCs. In this study, effects of additives on the surface properties of the MEA was investigated to improve homogeneity of the coated catalyst layer. Another parameter that affects on characteristics of the MEAs is hot-pressing condition. Hot pressing condition was optimized by using DOE (design of experiment) method.
Operation Results of the SOFC System Using 2 Sub-Module Stacks
Lee, Tae-Hee ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 405~411
A 5kW class SOFC cogeneration system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a stack, a fuel reformer, a catalytic combustor, and heat exchangers. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. A 5kW stack was designed to integrate 2 sub-modules. In this paper, the 5kW class SOFC system was operated using 2 short stacks connected in parallel to test the sub-module and the system. A short stack had 15 cells with
area. When a natural gas was used, the total power was about 1.38 kW at 120A. Because the sub-modules were connected in parallel and current was loaded using a DC load, voltages of sub-modules were same and the currents were distributed according to the resistance of sub-modules. The voltage of the first stack was 11.46 V at 61A and the voltage of the second stack was 11.49V at 59A.
Hydrogen Production from Steam Reforming of n-Hexadecane over Ni-Based Hydrotalcite-Like Catalyst
Lee, Seung-Hwan ; Moon, Dong-Ju ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 412~418
Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at
at atmospheric pressure with space velocity of
and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by
-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/
catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.
The Results of the 125 kW External Reforming Type MCFC Stack Operation
Lee, Jung-Hyun ; Kim, Beom-Joo ; Kim, Do-Hyeong ; Kang, Seung-Won ; Kim, Eui-Hwan ; Lim, Hee-Chun ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 419~424
The 125kW external reforming (ER) type molten carbonate fuel cell (MCFC) system for developing a commercial prototype has been operated at Boryeong thermal power plant site since the end of 2009. The system consists of 125kW stack with
effective area, mechanical balance of plant (MBOP) with anode recycle system, and electrical balance of plant (EBOP). The 125kW MCFC stack installed in December, 2009 has been operated from January, 2010 after 20 days pre-treatment. The stack open circuit voltage (OCV) was 214V at initial load operation, which approaches the thermodynamically theoretical voltage. The stack voltage remained stable range from 160V to 180V at the maximum generating power of 120 kW DC. The stack has been operated for 3,270 hours and operated at rated power for 1,200 hours.
A Study of Coal Gasification Process Modeling
Lee, Joong-Won ; Kim, Mi-Yeong ; Chi, Jun-Hwa ; Kim, Si-Moon ; Park, Se-Ik ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 425~434
Integrated gasification combined cycle (IGCC) is an efficient and environment-friendly power generation system which is capable of burning low-ranked coals and other renewable resources such as biofuels, petcokes and residues. In this study some process modeling on a conceptual entrained flow gasifier was conducted using the ASPEN Plus process simulator. This model is composed of three major steps; initial coal pyrolysis, combustion of volatile components, and gasification of char particles. One of the purposes of this study is to develop an effective and versatile simulation model applicable to numerous configurations of coal gasification systems. Our model does not depend on the hypothesis of chemical equilibrium as it can trace the exact reaction kinetics and incorporate the residence time calculation of solid particles in the reactors. Comparisons with previously reported models and experimental results also showed that the predictions by our model were pretty reasonable in estimating the products and the conditions of gasification processes. Verification of the accuracy of our model was mainly based upon how closely it predicts the syngas composition in the gasifier outlet. Lastly the effects of change oxygen are studied by sensitivity analysis using the developed model.
A Study on Characteristics of Power Generation System Using Biogas from the Waste of Pig Farm
Huynh, Thanh-Cong ; Pham, Xuan-Mai ; Nguyen, Dinh-Hung ; Tran, Minh-Tien ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 435~441
To verify the possibility of a power generation system using biogas from the waste of pig farm for rural electric production, a SI gasoline engine is modified to use biogas fuel and was installed in a 20 KVA power generation system. An electronic speed regulation unit is developed to keep the system speed at 1500 rpm. Experimental investigations have been carried out to examine the performance characteristics of power generation system (such as: system frequency, phase output voltage,
). In addition, the operating parameters and output emissions (
, HC, and
) of biogas-fueled engine are preliminary evaluated and analyzed for the change of system load. Results indicated that the researched power generation system shows a high stability of output voltage and frequency with help of speed regulator. Biogas fuel (mainly
) has an environmental impact and potential as a green alternative fuel for SI engine and they would not require significant modification of existing engine hardware. Output emissions of biogas-fueled engine are found to be relative low.
emission increases with the increase of output electric power of the power generation system.
The Calculation Method of Coal Pyrolysis Products Depending on the Coal Rank
Pak, Ho-Young ; Seo, Sang-Il ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 442~451
This paper describes the calculation method to obtain the product composition of coal pyrolysis at high pressure and high temperature. The products of coal pyrolysis should be determined for the coal gasifier simulation, and this is the first step of the coal gasifier simulation. The pyrolysis product distribution greatly affects the coal gasifier efficiency such as carbon conversion, cold gas efficiency and the syngas composition at the outlet of the gasifier. The present calculation method is based on the coal ultimate/proximate analysis and several correlations among gasifier pressure, coal properties and pyrolysis products. The calculated products for 5 coals have been compared with those from the commercial pyrolysis model.
A Study on Syngas Co-Combustion Characteristics in a 0.7 MWth Water-Tube Boiler with Single Heavy Oil Burner
Choi, Sin-Yeong ; Yang, Dong-Jin ; Bang, Byoung-Yeol ; Yang, Won ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 452~459
This study is aimed to investigate changes of combustion characteristics and heat efficiency when syngas from gasification process using low-rank fuel such as waste and/or biomass is applied partially to an industrial boiler. An experimental study on syngas co-combustion was performed in a 0.7 MW (1 ton steam/hr) water tube boiler using heavy oil as a main fuel. Three kinds of syngas were used as an alternative fuel: mixture gas of pure carbon monoxide and hydrogen, syngas of low calorific value generated from an air-blown gasification process, and syngas of high calorific value produced from an oxygen-blown gasification process. Effects of co-combustion ratio (0~20%) for each syngas on flue gas composition were investigated through syngas injection through the nozzles installed in the side wall of the boiler and measuring
, CO and NOx concentrations in the flue gas. When syngas co-combustion was applied, injected syngas was observed to be burned completely and NOx concentration was decreased because nitrogen-containing-heavy oil was partially replaced by the syngas. However, heat efficiency of the boiler was observed to be decreased due to inert compounds in the syngas and the more significant decrease was found when syngas of lower calorific value was used. However, the decrease of the efficiency was under 10% of the heat replacement by syngas.
The Process Simulation of Entrained Flow Coal Gasification in Dynamic State for 300MW IGCC
Kim, Mi-Yeong ; Joo, Yong-Jin ; Choi, In-Kyu ; Lee, Joong-Won ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 460~469
To develop coal gasfication system, many studies have been actively conducted to describe the simulation of steady state. Now, it is necessary to study the gasification system not only in steady state but also in dynamic state to elucidate abnormal condition such as start-up, shut-down, disturbance, and develop control logic. In this study, a model was proposed with process simulation in dynamic state being conducted using a chemical process simulation tool, where a heat and mass transfer model in the gasifier is incorporated, The proposed model was verified by comparison of the results of the simulation with those available from NETL (National Energy Technology Laboratory) report under steady state condition. The simulation results were that the coal gas efficiency was 80.7%, gas thermal efficiency was 95.4%, which indicated the error was under 1 %. Also, the compositions of syngas were similar to those of the NETL report. Controlled variables of the proposed model was verified by increasing oxygen flow rate to gasifier in order to validate the dynamic state of the system. As a result, trends of major process variables were resonable when oxygen flow rate increased by 5% from the steady state value. Coal flow rate to gasifier and quench gas flow rate were increased, and flow rate of liquid slag was also increased. The proposed model in this study is able to be used for the prediction of gasification of various coals and dynamic analysis of coal gasification.
Effects of Different Coal Type on Gasification Characteristics
Park, Se-Ik ; Lee, Joon-Won ; Seo, Hea-Kyung ;
Transactions of the Korean hydrogen and new energy society, volume 21, issue 5, 2010, Pages 470~477
The IGCC (Integrated gasification combined cycle) is known for one of the highest efficiency and the lowest emitting coal fueled power generating technologies. As the core technology of this system is the gasifier to make the efficiency and the continuous operation time increase, the research about different coal's gasification has been conducted. Our research group had set-up the coal gasifier for the pilot test to study the effect of different coals-Shenhua and Adaro coal- on gasification characteristics. Gasification conditions like temperature and pressure were controlled at a fixed condition and coal feed rate was also controlled 30 kg/h to retain the constant experimental condition. Through this study we found effects of coal composition and
/coal ratio on the cold gas efficiency, carbon conversion rate. The compounds of coal like carbon and ash make the performance of gasifier change. And carbon conversion rate was decreased with reduced
/coal ratio. The optical
/coal ratio is 0.8 for the highest cold gas efficiency approximately. At those operating conditions, the higher coal has the C/H ratio, the lower syn-gas has the