• Transactions of the Korean hydrogen and new energy society
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• v.30 no.1
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• pp.35-42
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• 2019

Recently, the gradual increase in energy acceptance is mostly satisfied by fossil fuels, but research and development of renewable energy sources are attracting attention due to fossil fuel supply and greenhouse gas problem. The disadvantage is that renewable energy can not be produced continuously. This being so, energy storage is an important technology in renewable energy. In this study, microwave was used to convert carbon receptor-carbon dioxide to gas fuel.

• Current Applied Physics
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• v.18 no.12
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• pp.1480-1485
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• 2018

Mesoporous carbon-silica composites supported Pt nanoparticle catalysts (Pt/MCS) were firstly applied to the heterogeneous asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutyrate (EOPB). A series of different silica contents were investigated in the fabrication of this mesoporous material. When the volume of added tetraethyl orthosilicate (TEOS) during the preparation of composites is 8 mL, Pt/MCS-8 holds carbon and silica as the main components and possesses relatively strong acidity, mesoporous structures with micropores, appropriate Pt nanoparticle size and high dispersibility showing by XRD, XPS, TPD, $N_2$ sorption and TEM. These properties cause its good catalytic performance in the heterogeneous asymmetric hydrogenation of EOPB with the enantiomeric excess value and conversion up to 85.6% and 97.8%, respectively.

• New & Renewable Energy
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• v.20 no.1
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• pp.126-134
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• 2024

Biogas, composed mainly of methane (CH₄) and carbon dioxide (CO₂), is a renewable gas that can serve as an alternative energy source. In this study, we developed a new microwave reformer and analyzed its reforming characteristics. We observed that higher temperatures of the microwave receptor led to increased reforming efficiency. By supplying appropriate amounts of methane and steam, we could prevent carbon generated from the thermal decomposition reaction of carbon dioxide from depositing on the catalytic active layer, thus avoiding the inhibition of catalytic activity. Hydrogen generation was enhanced when maintaining the biogas ratio and steam supply at adequate levels. Increasing the SiC ratio in the receptor improved the uniformity of temperature distribution and growth rate, resulting in higher conversion rates of the reforming process.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.37-42
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• 2009

We are in search for many method at 21th century thinking about the environment internationally. One is among them low carbon green city. Consequently this dissertation put a system solar energy key point of low carbon green city and purpose of low carbon green city Besides system and technique about the solar energy best practices try to do the investigation analysis. It's important of low carbon green city's environmental friendly system such as solar heat system, solar power generation, ecological greening, All these systems are connected each other and organize low carbon green city. A solar energy system uses pure energy of the situation directly most among the environmental friendly system. Energy saving and environment-friendly city in the world must do not a choice. However, recognition conversion and infrastructure of the Korea still has not come true. But South Korea and the international best practices is not the same system. But plan to solar city, the concept of green city in Cheongju, Deagu local government. And many meetings are in progress.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.97-104
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• 2013

Methyl alcohol is one of the basic intermediates in the chemical industry and is also being used as a fuel additive and as a clean burning fuel. In this study, conversion of carbon dioxide to methyl alcohol was investigated using catalytic chemical methods. Ceramic monoliths (M) with $400cell/in^2$ were used as catalyst supports. Monolith-supported CuO-ZnO catalysts were prepared by wash-coat method. The prepared catalysts were characterized by using ICP analysis, TEM images and XRD patterns. The catalytic activity for carbon dioxide hydrogenation to methyl alcohol was investigated using a flow-type reactor under various reaction temperature, pressure and contact time. In the preparation of monolith-supported CuO-ZnO catalysts by wash-coat method, proper concentration of precursors solution was 25.7% (w/v). The mixed crystal of CuO and ZnO was well supported on monolith. And it was known that more CuO component may be supported than ZnO component. Conversion of carbon dioxide was increased with increasing reaction temperature, but methyl alcohol selectivity was decreased. Optimum reaction temperature was about $250^{\circ}C$ under 20 atm because of the reverse water gas shift reaction. Maximum yield of methyl alcohol over CuO-ZnO/M catalyst was 5.1 mol% at $250^{\circ}C$ and 20 atm.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.54-60
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• 2023

In this study, microstructure and basic property analysis of DG (Desulfurization gypsum) and CCMs (Carbondioxide conversion capture materials) made by reacting CO₂ with DG were conducted to analyze applicability as a cement admixture. The main crystalline phases of DG were CaO and CaSO₄, and CCMs were CaSO₄, CaCO₃, Ca(OH)₂ and CaSO₄·H₂O. As a result of particle size analysis, the difference in average particle sizes between the two materials was about 7 ㎛. No major heavy metals were detected in the CCMs, and as a result o f TGA, the CO₂ decomposition of CCMs was more than twice as high as that of DG. Therefore, it was judged that CCMs could be used as a cement admixture through optimization of manufacturing conditions. As a results of measuring the strength behavior of DG and CCMs mixture ratios, the long-term strength of CCMs-mixed mortar was higher, and this is due to the filler effect of CaCO₃ in CCMs.

• Journal of Electrochemical Science and Technology
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• v.1 no.1
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• pp.19-24
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• 2010

Alloying degree is an important structural factor of PtRu catalysts for direct methanol fuel cells (DMFC). In this work, carbon supported PtRu catalysts were synthesized by reduction method using anhydrous ethanol as a solvent and $NaBH_4$ as a reducing agent. Using anhydrous ethanol as a solvent resulted in high alloying degree and good dispersion. The morphological structure and crystallanity of synthesized catalysts were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM). CO stripping and methanol oxidation reaction were measured. Due to high alloying degree catalyst prepared in anhydrous ethanol, exhibited low onset potential for methanol oxidation and negative peak shift of CO oxidation than commercial sample. Consequently, samples, applying ethanol as a solvent, exhibited not only enhanced CO oxidation, but also increased methanol oxidation reaction (MOR) activity compared with commercial PtRu/C (40 wt%, E-tek) and 40 wt% PtRu/C prepared in water solution.

• Korean Journal of Organic Agriculture
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• v.16 no.3
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• pp.287-298
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• 2008

This experiment was carried out to investigate the effect of different feed conditions on growth, cast production and conversion efficiency of organic matter to the earthworm. The experiment was tested on cow manure(CM) mixed with rice hulls (RH) or rice straw(RS). The mixture ratios were designed as one time, two times and three times of cow manure volume, respectively. The CM and RH mixtures resulted better on growth rate, reproductive efficiency and wormcast production than those for CM and RS mixtures. Especially on three times of RH mixture showed the highest growth characteristics compared to the other mixtures. Although both were between 20 and 34 on carbon and nitrogen ratio, the result inferred that the difference on the growth might have been caused by feeding conditions. On the mixtures of cow manure with rice hulls(CM+RH) was significantly higher on values on the conversion rate and conversion efficiency of organic matter to earthworm tissues than the mixtures of cow manure with rice straw(CM+RS). The most concerned point of the mixture of earthworm feed is that high contents of volatile solid and total carbon that increases in conversion efficiency of organic matter to earthworm tissues, and also causes the increase in growth rate and reproductive efficiency. The wormcast could be used as a valuable plant growth medium or soil conditioner for sustainable agriculture and it may be due to their high qualities of physico-chemical properties.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1275-1279
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• 2004

Citron peel oil was extracted from citron (Citrus funas) fruit by steam distillation, and was used as starting material for microbial conversion to synthesize attractive flavor compounds by using Enterobacter agglomerans 6L. E. agglomerans was isolated from citron peel and was able to metabolize the citron peel oil and grew well ($A_{600}:\;3.0$) on the citron peel oil as the sole carbon source. Multiple terpene metabolites were produced by E. agglomerans 6L on M9 salt media with citron oil vapor. The identified bioconversion products from the citron peel oil included trans-2-decenal, octanol, $\delta$­valerolactone, $\gamma$-valerolactone, cryptone, hydroxycitronellol, cuminol, and $\gamma$-dodecalactone.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.9
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• pp.18-25
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• 2012

Recently, the depletion of fossil fuel carbon dioxide emissions due to limitations in the internal combustion engine vehicles is rising concern about electric vehicle. Neighborhood Electric Vehicle(NEV) is maximum speed 60km/h and one day driving distances less than 80km. In this paper, Power Conversion Controller is proposed for Neighborhood Electric Vehicle. To verify the developed Power conversion Controller, Test performed integration test, max load, power density, efficiency. Confirmed that the vehicle can be applied.