• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2187-2192
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• 2011

Hydrogen peroxide plays a key role as a second messenger in the normal cellular signaling but its overproduction has been implicated in various life-threatening diseases. Peroxalate chemiluminescence is the light emission from a three component reaction between peroxalate, hydrogen peroxide and fluorophores. It has proven great potential as a methodology to detect hydrogen peroxide in physiological environments because of its excellent sensitivity and specificity to hydrogen peroxide. We developed chemiluminescent micelles composed of amphiphilic polymers, peroxalate and fluorescent dyes to detect hydrogen peroxide at physiological concentrations. In this work, we studied the relationship between the chemiluminescence reactivity and stability of peroxalate by varying the substitutes on the aryl rings of peroxalate. Alkyl substitutes on the aryl ring of peroxalate increased the stability against water hydrolysis, but diminished the reactivity to hydrogen peroxide. Chemiluminescent micelles encapsulating diphenyl peroxalate showed significantly higher chemiluminescence intensity than the counterpart encapsulating dimethylphenyl or dipropylphenyl peroxalate. Diphenyl peroxalate-encapsulated micelles could detect hydrogen peroxide generated from macrophage cells stimulated by lipopolysaccharide (LPS) and image hydrogen peroxide generated during LPS-induced inflammatory responses in a mouse.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.111-115
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• 1996

Metal atom rearrangement has been shown to take place under the influence of hydrogen-induced atomic diffusion (HIAD) in initially homogeneous fee palladiumalloys by electron microprobe analysis, optical microscopy, mechanical property tests and hydrogen isotherms. HIAD takes place in palladium alloys at moderate to elevated temperatures leading to phase segregation under conditions where segregation does not normally occur, i.e., in the absence of H over the time scale of the experiments. From these results, it is confirmed that dissolved hydrogen plays a dual role in some of these alloys, i.e. it catalyzes metal atom diffusion. This research demonstrates the potential utility of employing H-induced changes for phase diagram determination of Pd alloys and possibly for other alloy system.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.2
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• pp.175-184
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• 2024

This study focuses on investigating the importance of managing greenhouse gas emissions from global energy consumption, specifically examining domestic targets for clean hydrogen production. Using life cycle assessment, we evaluated reductions in global warming potential and assessed the carbon neutrality contribution of the domestic hydrogen sector. Transitioning from brown or grey hydrogen to blue or green hydrogen can significantly reduce emissions, potentially lowering CO₂ equivalent levels by 2030 and 2050. These research findings underscore the effectiveness of clean hydrogen as an energy management strategy and offer valuable insights for technology development.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.634-637
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• 2005

Hydrogen adsorption mechanism onto the porous metal-organic frameworks (MOFs) has been studied by density functional theory calculation. The selected functionals for the predict ion of interact ion energies between hydrogen and potential adsorption sites of MOF was utilized after the evaluation with the various functionals for interaction energy of $H_2C_6H_6$ model system the adsorption energy of hydrogen molecule into MOF was investigated with the consideration of the favorable adsorption sites and the orientations. We also calculated the second favorable adsorption sites by geometry optimization using every combination of two first absorbed hydrogen molecules. Based on the calculation of first and second adsorption sites and energies, the hydrogen adsorption into MOF follows a cooperative mechanism in which the initial metal sites initiate the propagation of the hydrogen adsorption on the whole frameworks. In addition, it was found that the interaction strength between the simple benzene ring with hydrogen is significantly reinforced when the benzene ring has been incorporated into the framework of MOFs.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.5
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• pp.410-415
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• 2009

A hydrogen cooling method is used in a power generator for removing the unnecessary heat due to the windage loss of a rotor and the joule heat of a stator. A MEA (Membrane Electrolyte Assembly) hydrogen generator has been developed and applied as a hydrogen supplying system for the cooling of a 350MW power generator. As a field application result, the average potential of eleven cells and the voltage efficiency were measured 2.26V/cell and 65.4% (Higher Heating Value) respectively at the hydrogen pressure of 6 Bar, the hydrogen flow rate of 9.1L/min, and the current of 150A.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.688-696
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• 2011

Hydrogen is one of the few long-term sustainable clean energy carriers, emitting only water as by-products during its combustion or oxidation. The use of fossil fuels to produce hydrogen makes large amount of carbon dioxide (>7 kg $CO_{2}$/kg $H_{2}$) during the reforming processes. Hydrogen production can be environmentally benign only if the energy and the resource to make hydrogen is sustainable and renewable. Biomass is an attractive alternative to fossil fuels for carbon dioxide because of the hydrogen can be produced by conversion of the biomass and the carbon dioxide formed during hydrogen production is consumed by biomass generation process. Hydrogen production using solar energy also attracts great attention because of the potential to use abundance natural energy and water.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.111-114
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• 1996

Hydrogen generation by dissociation of water is described. The major force for the dissociation comes from the oxidation potential of the reactive metal reacting with water whereas the minor role is played by electrical discharge which helps sustain the reaction. A premixed reactive metal/water system undergoes a fast hydrogen generation upon the ignition by an electrical pulse. In another method the reactive metal can be fed into the discharge. Some characteristics of the methods are discussed.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.667-672
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• 2019

As a non-renewable energy source, fossil fuel causes environment problems, numerous efforts have been made for a global decarbonization, for example, the realization of Power 2 Gas (P2G) system as a definitive research goal. In particular, ammonia is regarded as an emerging source since it can be used as a hydrogen carrier and production alongside for fuel cell applications. In this mini-review, we summarized the properties of ammonia and further highlighted the worldwide research trend for its superb potential in hydrogen energy supply industries.

• New & Renewable Energy
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• v.18 no.2
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• pp.50-59
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• 2022

The Korean government announced the "1st Basic Plan for the Transition to Hydrogen Economy" in 2021 and declared the establishment of a hydrogen industry ecosystem by 2040. To build a low-carbon power system, resources that can efficiently accommodate renewable energy are required, and green hydrogen is considered a potential solution. This study analyzed the economic feasibility of green hydrogen-based sector coupling to reduce curtailment of renewable generation in the Jeju power system by 2025 under the scenario of with or without HVDC#3. The result showed that HVDC#3 significantly reduced the frequency of curtailment from 16.1% to 3.0%. In addition, green hydrogen-based sector coupling was an economically feasible option as result showed an IRR of 4.86% when HVDC#3 was connected and 11.45% when it was not under the condition of achieving 50% curtailment reduction. This study shows that the higher the level of renewable energy deployment, the more delayed the HVDC connection between Jeju and the main land, and the lower the SMP, the more economically feasible the green hydrogen-based sector coupling is. Furthermore, this study suggests that the policy goal of completely reducing curtailment is not economically efficient.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.267-273
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• 2023

As the impacts of global climate change become increasingly apparent, the reduction of carbon emissions has emerged as a critical subject of discussion. Nuclear power has garnered attention as a potential carbon-free energy source; however, the rapidity of load following in nuclear power generation poses challenges in comparison to fossil-fueled methods. Consequently, power-to-gas systems, which integrate nuclear power and hydrogen, have attracted growing interest. This study presents a preliminary design of a very high temperature reactor (VHTR) integrated blue hydrogen production process utilizing DWSIM, an open-source process simulator. The blue hydrogen production process is estimated to supply the necessary calorific value for carbon capture through tail gas combustion heat. Moreover, a thermodynamic assessment of the main recuperator is performed as a function of the helium flow rate from the VHTR system to the blue hydrogen production system.