• 대한화학회지
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• 제8권4호
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• pp.188-191
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• 1964

微量元素分析用 燃燒爐 內에서 內部酸化劑(酸化銀과 二酸化 망간의 混合物)와 함께 有機試料를 헤륨 氣流下에서 燃燒시키고 發生한 물은 칼슘카바이드管에 通하여 아세틸렌으로 變換시킨다. 二酸化炭素와 아세틸렌을 molecular sieve 5A 管에 室溫에서 吸着시킨 후 $340^{\circ}C$까지 溫度${\cdot}$프로그탬法으로 脫着시켜 실리카켈管을 通하여 分別流出시키고 熱傳導式 檢知器로 $CO_2$와 $C_2H_2$를 定量하는 方法을 發展시켰다. 벤조酸을 標準物質로 하여 作成한 檢量線을 使用하여 各種 有機試料中의 炭素 및 水素含量을 分析한 結果 平均誤差가 炭素의 경우 ${\pm}0.5%$, 水素인 경우${\pm}0.33%$ 이었다.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.529-532
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• 2007

Combined temperature programmed reaction (TPR) and infrared (IR) spectroscopic studies for Fischer- Tropsch reaction have been performed over Ru/SiO2 and Ru-Ag/SiO2 supported catalysts. Reaction of linearly absorbed CO with hydrogen starts at 375 K over Ru/SiO2 catalyst and reaches maximum at 420 K accompanied with an intensity decrease of linear CO absorption. The reaction with bridged absorbed CO peaks around 510-535 K. Addition of Ag yields mixed Ru-Ag bimetallic sites while it suppresses the formation of bridged bonded CO. Formation of methane on this modified surface occurs at 390 K and reaches maximum at 444 K. Suppression of hydrogen on the Ag-doped surface also occurs resulting in the formation of unsaturated hydrocarbons and of CHx intermediates not observed with Ru/SiO2 catalyst. Such intermediates are believed to be the building blocks of higher hydrocarbons during the Fischer-Tropsch synthesis. Linearly absorbed CO is found to be more reactive as compared to bridged CO. The Ag-modified surface also produces CO2 and carbon. On this surface, hydrogenation of CO begins at 390 K and reaches maximum at 494 K. The high temperature for hydrogenation of absorbed CO and C over Ru-Ag/SiO2 catalyst as compared to Ru/SiO2 catalyst is due to the formation of Ru-Ag bimetallic surfaces impeding hydrogen adsorption.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.192-200
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• 2016

A characteristics of microwave drying-gasification was analyzed for converting a dewatered sewage sludge generated a wastewater treatment plant. Gas (60%) was the largest component of the product of microwave gasification, followed by sludge char (33%) and tar (2%). The main components of the producer gas were hydrogen (33%) and carbon monoxide (40%), and there was some methane and hydrocarbons ($C_2H_4$, $C_2H_6$, $C_3H_8$). Larger nitrogen and smaller oxygen amounts were generated. Gravimetric tar generated $414g/m^3$. This means a total tar which is a heavy hydrocarbons from the volatile organic substance in the sewage sludge. Selected light tars were benzene, anthracene, naphthalene, pyrene, showing lower concentrations as 2.62, 0.37, 0.49, $0.28g/m^3$, respectively. Sludge char has larger meso pores which is a mean pore size of $50.85{\AA}$ and has high adsorptivity. An amount of adsorption was $228.71cm^3/g$, showing higher quantity than acommercial adsorbers. This indicates that the gas obtained from the microwave gasification of wet sewage sludge can be used as fuel, but the heavy tar in the gas must be treated. Sludge char can be used as a tar reduction adsorbent in the process, and then burns as a solid fuel.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.416-424
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• 2018

Microstructure of oxide formed on Zr-Nb-Sn tube sample was intensively examined by scanning transmission electron microscopy after exposure to simulated primary water chemistry conditions of various concentrations of Zn (0 or 30 ppb) and dissolved hydrogen ($H_2$) (30 or 50 cc/kg) for various durations without applying desirable heat flux. Microstructural analysis indicated that there was no noticeable change in the microstructure of the oxide corresponding to water chemistry changes within the test duration of 100 days (pretransition stage) and no significant difference in the overall thickness of the oxide layer. Equiaxed grains with nano-size pores along the grain boundaries and microcracks were dominant near the water/oxide interface, regardless of water chemistry conditions. As the metal/oxide interface was approached, the number of pores tended to decrease. However, there was no significant effect of $H_2$ concentration between 30 cc/kg and 50 cc/kg on the corrosion of the oxide after free immersion in water at $360^{\circ}C$. The adsorption of Zn on the cladding surface was observed by X-ray photoelectron spectroscopy and detected as ZnO on the outer oxide surface. From the perspective of $OH^-$ ion diffusion and porosity formation, the absence of noticeable effects was discussed further.

• Korean Chemical Engineering Research
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• 제49권1호
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• pp.1-9
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• 2011

티타니아, 바나디아, 지르코니아, 세리아를 고정한 실리카에 백금을 담지한 후 과산화수소로 처리하여 제조한 백금 촉매에서 산화물 고정과 과산화수소 처리가 백금의 분산 상태 및 일산화탄소 산화반응에서 이들의 촉매 활성에 미치는 영향을 조사하였다. 산화물을 고정하고 과산화수소로 처리하면 실리카에도 백금이 잘 분산될 수 있음을 XRD, TEM, EXAFS, XPS, 일산화탄소 화학흡착 방법으로 검증하였다. 그러나 일산화탄소의 흡착성질과 일산화탄소 산화반응에서 촉매 활성은 고정한 산화물 종류에 따라 상당히 달랐다. 티타니아, 지르코니아, 세리아를 실리카에 고정하고 과산화수소로 처리하여 제조한 백금 촉매에서는 백금의 분산도가 높아져서 일산화탄소 산화반응에서 활성이 증진되었다. Pt-O-Zr 결합이 생성되어 백금의 분산도가 크게 향상된 지르코니아 고정 백금 촉매에서 산화물 고정과 과산화수소 처리로 인한 활성 증진 효과가 가장 컸다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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• pp.66-71
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• 2005

The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream. The sulphidation of waste seashells with $H_2S$ was studied in a thermogravimetric analyzer at temperature between 600 and 800$^{\circ}C$. The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affect the $H_2S$ removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electron microscopy.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제22회 학술발표회 초록집
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• pp.57-57
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• 2002

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.378-380
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• 2005

The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream, The sulphidation of waste seashells with H$_2$S was studied in a thermogravimetric analyzer at temperature between 600 and 800${\circ}$C . The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affect the H2S removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electron microscopy.

• 한국염색가공학회지
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• 제1권1호
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• pp.26-34
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• 1989

The selective chemical degradation or etching of PET based on an organic amine attack on the ester group. The techniques involves the chemical removal of loss ordered amorphous regions or crystalline regions, which are essentially unaffected by the degradative etchant. Thus, most of previous studies have limited to consideration which has been given to structural changes taking place. Therefore, this study was carried out to investigate surface characterization, dyeing properties of PET film hydrazinolyzed with hydrazine hydrate in methanol. PET film was treated with 30% hydrazine hydrate in methanol at $30^\circ{C}$ for various time intervals. The total surface tension of treated PET increased, the dispersion force decreased and the hydrogen bonding force increased. The equilibrium dye adsorption, dyeing rate and apparent diffusion coefficient of acid dyes increased, and the apparent activation energies of diffusion decreased.

• 한국물환경학회지
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• 제26권3호
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• pp.525-531
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• 2010

To figure out the importance of temperature on electrochemical properties in water environment, calcium carbonate, one of important substances in water chemistry, was chosen to make suspensions. The result of electrokinetic potential of calcium carbonate suspensions revealed that it tended to increase as temperature increased. In addition, electrokinetic potential was negatively increased as suspensions became more basic. Its isoelectric point was ca. 7 regardless of temperature. The adsorption of hydrogen ions on calcium carbonate particles followed endothermic reaction. This result was verified by continuously measuring pH as adding HCl solution in calcium carbonate suspension. It explained that suspensions' potential was determined by DLVO theory which calculated total interaction energy between particles. Suspensions' total interaction energy was proportional to the value of electrokinetic potential. Furthermore, total interaction energy between particles increased as suspensions' temperature was increased.