• Journal of Hydrogen and New Energy
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• v.22 no.6
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• pp.934-941
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• 2011

Characteristics of low NOx burner is investigated. Low NOx burner introduced in this paper adopts two staged combustion with plasma burner for the 1st stage combustion. Extensive parametric tests were done to figure out the effect of burner stoichiometry, staged thermal load, electric power for plasma generation. Overall NOx production by burner shows effective reduction by adopting plasma staged burner. and the aspects depends on the fuel stoichiometry of 1st stage burner or operating condition of plasma burner. It is promising to use plasma burner as an alternative tools of low NOx burner technology.

• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.413-419
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• 2019

In the recent, as a world demand of energy resources has been transformed from fossil fuels to hydrogen-based clean energy resources, a huge attention has been attracted to increase the performance and decrease a production cost of core materials in fuel cell technology. The utilization of reinforced composite membranes as electrolytes in the polymer electrolyte membrane fuel cells can reduce the use of high cost perfluorosulfonic acid (PFSA), mitigate the cell impedance, and improve the dimensional stability as well as the interfacial stability, giving rise to achieve both an improved performance and a reduction of production costs of the fuel cell devices. In this study, we investigate the effects of physical characteristics and cell performances according to the various ionomer solvents in the solution based manufacturing process of reinforced composite electrolyte membrane.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.640-645
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• 2018

The design of non-precious electrocatalysts with low-cost, good stability, and an improved oxygen reduction reaction(ORR) to replace the platinium-based electrocatalyst is significant for application of fuel cells and metal-air batteries with high energy density. In this study, we synthesize iron-carbide($Fe_3C$) embedded nitrogen(N) doped carbon nanofiber(CNF) as electrocatalysts for ORRs using electrospinning, precursor deposition, and carbonization. To optimize electrochemical performance, we study the three stages according to different amounts of iron precursor. Among them, $Fe_3C$-embedded N doped CNF-1 exhibits the most improved electrochemical performance with a high onset potential of -0.18 V, a high $E_{1/2}$ of -0.29 V, and a nearly four-electron pathway (n = 3.77). In addition, $Fe_3C$-embedded N doped CNF-1 displays exellent long-term stabillity with the lowest ${\Delta}E_{1/2}=8mV$ compared to the other electrocatalysts. The improved electrochemical properties are attributed to synergestic effect of N-doping and well-dispersed iron carbide embedded in CNF. Consequently, $Fe_3C$-embedded N doped CNF is a promising candidate for non-precious electrocatalysts for high-performance ORRs.

• Korean Journal of Metals and Materials
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• v.46 no.10
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• pp.646-651
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• 2008

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, yttria-stabilized zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at $675^{\circ}C$ for 216 hours in the molten salt $LiCl-Li_2O$ under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of $LiCl-Li_2O$ molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.220-227
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• 2010

The manufacturing of the solid fuel using wastes has been studied on the purpose of the reduction of green house gases and the profit-making as alternative fuel, and thus, it has become as technically improved as to be used as business. However, the production of solid fuel with multi-wastes combination needs a caution while the solid fuel with one-waste has not a significant component change. This study analyzes the solid fuel components through the practical plant experiment to the various wastes. The resulted data shows a different pattern than the theoretical one in the component analysis, and it can be concluded that the adequate uniform mixing has a great influence on the manufacturing of the solid soil.

• Korean Journal of Metals and Materials
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• v.47 no.12
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• pp.852-859
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• 2009

The manufacturing process of zirconium alloys is an import factor to increase their strength and corrosion resistance. In order to find an improved manufacturing process of zirconium alloys in both Zr-1Nb-1Sn-0.1Fe (Alloy-A) and Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr (HANA-4) for fuel guide tubes, sheet samples were prepared by applying two- and three-step processes that were controlled by an annealing and reduction condition. The mechanical strength and corrosion resistance of both alloys were increased by applying the twostep process rather than the three-step process. From a matrix analysis using TEM, the property improvement is related to the decrease of the precipitate mean diameter with an application of the two-step process. In a comparison of the strength and corrosion properties between Alloy-A and HANA-4, the performance of HANA-4 was feasible for application to fuel guide tubes.

• Journal of Hydrogen and New Energy
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• v.29 no.6
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• pp.654-660
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• 2018

The dependence on global fossil fuels has been gradually reducing all over the world. Some countries which recognized the important of environmental values were joining to carry out international GHG goals. Our country has also participated with high targets (37% reduction compared to BAU 2030 years). So we need to supply materials of lower GHG value such as a bio-diesel. Bio-alcohol is one of the similar bio-fuels that can be reducing GHG. A lot of countries had tried to commercialize through various R&D for bio-alcohol. In this study, we analyzed the fuel characteristics of bio-alcohol fuel produced by domestic technology. And we evaluated a possibility to use as vehicle fuel through mixing of bio-alcohol and gasoline. The mixed fuels were satisfied with 2.3 wt% of oxygen content that is standard of the petroleum and petroleum alternative fuel business Act. We tried to evaluate a emission characteristic of vehicle by mixed fuel. In accordance with the results we tried to find a correlation between fuel and emission.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.2
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• pp.185-198
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• 2017

The application of composites as an alternative material for marine steel hatch covers is the subject of this study. Two separate approaches are considered; weight reduction approach and strengthening approach. For both approaches Finite Element Analysis (FEA) was performed using ANSYS software. Critical design parameters of the composite hatch cover and FEA are discussed in details. Regarding the weight reduction approach; steel hatch covers of a bulk carrier were replaced by composite covers and a weight reduction of 44.32% was achieved leading to many benefits including fuel saving, Deadweight Increment and lower center of gravity of the vessel. For the strengthening approach; the foremost hatch cover was strengthened to withstand 150% of the load required by IACS for safer navigation while no change in weight was made between the steel and composite covers. Results show that both approaches are feasible and advantageous.

• Carbon letters
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• v.14 no.2
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• pp.117-120
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• 2013

In this study, an electro-catalyst of Pt nanoparticles supported by polypyrrole-functionalized graphene (Pt/PPy-reduced graphene oxide [RGO]) is reported. The Pt nanoparticles are deposited on the PPy-RGO composite by chemical reduction of H2PtCl6 using NaBH4. The presence of graphene (RGO) caused higher activity. This might have been due to increased electro-chemically accessible surface areas, increased electronic conductivity, and easier charge-transfer at polymer-electrolyte interfaces, allowing higher dispersion and utilization of the deposited Pt nano-particles. Microstructure, morphology and crystallinity of the synthesized materials were investigated using X-ray diffraction and transmission electron microscopy. The results showed successful deposition of Pt nano-particles, with crystallite size of about 2.7 nm, on the PPy-RGO support film. Catalytic activity for methanol electro-oxidation in fuel cells was investigated using cyclic voltammetry. The fundamental electrochemical test results indicated that the electro-catalytic activity, for methanol oxidation, of the Pt/PPy-RGO combination was much better than for commercial catalyst.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.467-470
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• 2003

Leaking underground storage tanks are a major source of groundwater contamination by petroleum hydrocarbons. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. However, Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Nitrate can also serve as an electron acceptor and results in anaerobic biodegradation of organic compounds via the processes of nitrate reduction and denitrification. Because nitrate is less expensive and more soluble than oxygen. it may be more economical to restore fuel-contaminated aquifers using nitrate rather than oxygen. And denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. These studies have shown that BTEX and MTBE can be degraded by the nitrate-amended microcosms under aerobic and anaerobic conditons. Biodegradation of the toluene and ethylbenzne compounds occurred very quickly under denitrifying conditions. MTBE, benzene and p-xylene were recalcitrant under denitrifying conditions in this study, But finally Biodegradaton was observed for all of the test compounds.