• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.103-115
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• 1981

The cathodic reactions of lead anodic films formed in phosphoric acid, oxalic acid and sodium hydroxide solutions and the reactivities of Di-iso-butylnitrosoamine (DBNA) in sea water at $15\sim30^{\circ}C$ were studied by means of constant current-potential method. Besides, various contants and thermodynamic quantities obtained in the experiment were also do-scribed to explain the reactivities of protons that entered in the anodic film by being transferred across the metal-oxide interface. The electrode reactions of lead anodic film formed in sodium hydroxide solution in 60mM DBNA+0.5M NaCl did not occur because of complete insulator formed on anodic film. The values of $(\partial\triangle E_{H^+}/\partial T)_{i=const}$, estimated with Bead anodic films formed in phosphoric acid in 60mM DBNA+0.5M NaCl and 60mM $DBNA+6\%_{\circ}$ sea water were $-0.006\;V/^{\circ}C\;and\;-0.005\;V/^{\circ}C$, thus being nearly coincided, but the values of $(\partial E_o/\partial T)_{i=o}$ were $0.002\;V/^{\circ}C\;and\;-0.002\;V/^{\circ}C$, being completely inversed.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.141-148
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• 1998

Reactivity of Pt catalysts(0.2, 0.5 wt% Pt) supported on solid super acid, $ZrO_2$ $SO_4{^{2-}}$ for low-temperature oxidation was investigated for complete oxidation of cyclohexane. Catalytic activity measured as reactant conversion in a packed-bed tubular reactor increased in accordance with the acidity and specific surface area of the catalyst activity and specific surface area of $Pt/ZrO_2$ $SO_4{^{2-}}$ catalyst were diminished by adding potassium during catalyst preparation. the catalyst activity decreased in accordance with the amount of potassium added. In addition, $Pt/ZrO_2$ $SO_4{^{2-}}$ catalyst exhibited an activity greater than that of a $Pt/SiO_2$ or $Pt/Al_2O_3$ catalyst possessing much larger specific surface area at $250^{\circ}C$ for the reactant stream of 15.000 ppm cyclohexane concentration and $18,000hr^{-1}$ space velocity, a cyclohexane conversion as high as 96% was obtained over 0.2 wt% $Pt/ZrO_2$ $SO_4{^{2-}}$, whereas cyclohexane conversions over 0.2 wt% $Pt/SiO_2$ and 0.2 wt% $Pt/Al_2O_3$ were 83 and 79%, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.89-96
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• 2006

The combustion temperature in gas generator should be kept below around 1,000K to avoid any possible thermal damages to turbine blade by adopting either fuel rich or oxidizer rich combustion. Thus, non-equilibrium chemical reaction dominates in the gas generator. Meanwhile, Kerosene is a compounded fuel mixed with various types of hydrocarbon elements and difficult to model the chemical kinetics. This study focus to model the non-equilibrium chemical reaction of kerosene/LOX with detailed kinetics developed by Dagaut using PSR(Perfectly stirred reactor) assumption. Also, droplet evaporation time is taken into account by calculating for the residence time of droplet and by decoupling reaction temperature from the reactor temperature. In Dagaut’s surrogate model for kerosene, chemical kinetics of kerosene consists of 1592 reaction steps with 207 chemical species. The comparison of calculation results with experimental data could provide very reliable and accurate numbers in the prediction of combustion gas temperature, species fraction and other gas properties.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.297-302
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• 2018

Bead type and hollow fiber type catalyst (HFC, Hollow Fiber type Catalyst) was prepared by $La_{0.1}Sr_{0.9}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ (LSCF1928) perovskite powder catalyst which showed excellent methane complete oxidation characteristics through previous studies. The HFC have a cylindrical shape with an empty interior, and pores can be formed through Phase inversion method so the specific surface area can be remarkably improved. In the case of the bead type catalyst prepared by adding Methyl Cellulose (MC), $SrCO_3$ was produced in addition to the original catalyst composition of LSCF1928 due to the reaction of $CO_2$ emitted from MC and Sr of the catalyst. In the case of the HFC, a single phase perovskite structure was obtained without impurities. The HFC calcined at $700{\sim}900^{\circ}C$ showed pore structure of finger-sponge-finger structure, and 99.9% oxygen conversion rate was achieved through complete oxidation of methane at $475^{\circ}C$. Air gap and spinning pressure condition were changed to control the HFC pore. 2 cm air gap and 7 bar spinning pressure showed the best catalytic performance and achieved oxygen conversion rates of more than 70.65%, 93.01%, and 99.99% at $425^{\circ}C$, $450^{\circ}C$ and $475^{\circ}C$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.829-836
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• 2005

In this study, the characteristics of atrazine decompositon with photo-chemical oxidation process was investigated by the oxidation products analysis. The main products of the process were OIET(2-hydroxy-4-ethylamino-6-isopropylamino s-triazine), OIAT(2-hydroxy-4-amino-6-isopropylamino s-triazine) and OAAT(2-hydroxy-4,6-diamino-s-triazine), resulting i n dechlorination or hydroxylation as the main mechanism of the photo-chemical oxidation process. Through the material balance analysis of TOC and chloride ion in the aqueous solution, it was concluded that mineralization of the atrazine was not occurred but the dechlorination of atrazine had been completed.

• Korean Journal of Materials Research
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• v.6 no.4
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• pp.379-387
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• 1996

본 연구에서는 GaAs 소자제작 및 epi-layer 성장 공정에 있어 이용되어지는 HCI, H3PO4, 탈이온수(de-ionized water:DIW)를 통한 습식제정후 공기중 노출에 따른 오염을 최소화하여 표면상태 변화를 진성적(intrinsic)으로 관찰하고자 모든 세정처리를 아르곤 가스(argon gas)로 분위기가 유지되는 glove box에서 수행하였으며, 표면조성 및 결합상태 변화에 대한 관찰은 X-선 광전자 분광기(X-ray photoelectron spectroscopy)를 통해 이루어졌다. 고진공하에서 GaAs를 벽개하여 관찰함으로써 Ga이 대기중 산소이온과 우선적으로 결합함을 알 수 있었고, 이런 GaAs 표면의 반응성에 대한 고찰을 바탕으로 습식세정에 따른 화학반응 기구가 제시 되어졌다. HCI 및 H3PO4/DIW/HCI처리후 CI-이온의 Ga 이온과의 반응에 의한 Ga-CI결합의 형성과 As 산화물의 높은 용해도에 따른 As 산화물의 완전한 제거 및 식각전 초기(bare)GaAsvyaus에 존재하는 원소(elemental)As 상태의 식각후 잔류가 관찰되어졌다. 또 HCI, H3PO4/DIW/HCI 처리하고 DIW로 세척후 표면상태 변화를 관찰한 결과, DIW처리에 의해 elemental As 상태가 증가함을 알 수 있었다.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.62-67
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• 1994

Introduction : Recently, water and environmental pollution becomes serious social problem and high technology makes this pollution accelerate. Hydrogen sulfide, the main subject of our research, is one of the most dangerous air pollutant like SO$_x$ and NO$_x$. The major contaminant in coal gasification is H$_2$S, which is very toxic, hazardous and extremely corrosive. Therefore, control of hydrogen sulfide to a safe level is essential. Although commercial desulfurization process called liquid scrubbing is effective for removal of H$_2$S, it has drawbacks, the loss of sensible heat of the gas and costly wastewater treatment. Many investigations are carried out about high-temperature removal ol H$_2$S in hot coal-derived gas using metal oxide or mixed metal qxide sorbents. It was reported that ZnO was very effective sorbent for H2S removal, but it has big flaw to vaporize elemental zinc above 600\ulcorner \ulcorner As alternative, metal oxides such as CaO, $Fe_2O_3$, TiO$_2$ and CuO were added to ZnO. Especially, different results are reported for $Fe_2O_3$ additive. Tamhankar et al. reported SiO$_2$ with 45 wt% $Fe_2O_3$ sorbent is favorable for removal of H$_2$S and regeneration.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.358-360
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• 2006

축산폐수내의 질소 성분의 효율적인 처리를 위하여 생물학적 질산화반응과 방사선조사기술을 결합시키는 연구를 수행하였다. 축산폐수에 방사선을 조사하여 줌으로써 생성되는 라디칼들에 의하여 폐수내 난분해성 유기물들의 생분해도가 향상되어 짧은 HRT에도 불구하고 완전한 NH$_4^+$-N의 산화가 이루어졌다.

• Prospectives of Industrial Chemistry
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• v.19 no.5
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• pp.1-11
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• 2016

우리나라는 1970년대를 기점으로 하여 급격한 경제성장과 산업기술의 발전이 이루어졌다. 경제성장과 함께 주택의 보급 또한 급격하게 증가하게 되었고, 주택의 보급을 위한 건축자재 및 생활용품의 개발이 급속도로 이루어졌다. 이에 따라 실내에서 사용하는 기구 및 건축재료가 매우 다양해졌으며, 이로 인한 새로운 오염물질의 배출이 급격히 증가하게 되었다. 최근 새로운 기술로 소개되고 있는 촉매 산화법의 경우 제거하려는 대상 실내대기오염물질을 촉매를 이용하여 CO₂나 H₂O 등으로 산화시켜 제거하는 방법이며, 최근 많은 연구가 활발하게 수행되고 있다. 촉매를 이용하는 촉매 산화법은 광촉매 산화법과, 촉매의 성능만을 이용하여 대상물질을 산화하는 촉매산화법으로 구분된다. 광촉매 산화법은 특정 파장에서 반응하는 촉매에 자외선을 조사하여 실내오염물질을 산화제거하는 방법으로, 산화성능이 우수하여 여러 가지 실내오염가스에 적용되고 있으나, 별도의 광원이 필요하며, 포름알데히드 산화 시 CO₂와 H₂O 이외에도 dichloroacetyl chloride (C₂HCl₃O), trichloroethylene (C₂HCl₃), phosgene (COCl₂) 등과 같은 부수적인 2차 유해물질이 발생함에 따라 이를 처리하기 위한 대책이 수반되어야 한다. 반면, 촉매 산화법의 경우 별도의 광원이나 에너지원 없이, 촉매를 이용하여 대기오염물질을 인체에 무해한 물질로 완전 산화시키는 방법으로써, 최근 많은 연구가 수행되어 상온에서 구동 가능한 촉매가 개발되었고, 이의 연구가 활발히 이루어지고 있다. 이에 상온산화촉매기술의 연구동향 및 사례를 확인하고, 향후 상온산화촉매기술이 나아가야 할 방향을 제시하고자 한다. 본 연구는 환경부 환경산업선진화기술개발사업의 지원을 받아 수행되었습니다(2016000140004).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1036-1037
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• 2017

This study investigated the aging reactions of three kinds of igniters(BKNO3, THPP, ZPP). The life-time of igniter depends on oxygen and moisture in the air. For example, Magnesium contained in the $BKNO_3$ reacts with oxygen and water to form oxide and hydrate. This reaction has an adverse effect on ignition reaction and could be information to analyze aging. Thermodynamic calculation could interpret the aging reaction by calculating flame temperature applying several variables(initial temperature, composition, etc.). If combustion is not completed because of aging igniters, flame temperature will be formed at a low range. The result of this research is expected to support the analysis of igniters aging reactions.