• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.377-383
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• 2005

Because explosive fluid is used at high temperature or under high pressure in petrochemistry and refined oil equipment, the interest about safety of equipments is intensive. Specially, the safety of high pressure reactor vessel is required among them. The material selected in this study is 2.25Cr-1Mo steel that is widely used for high pressure reactor vessel material of petrochemical plant. Eight kinds of artificially aged specimens were prepared by differing from aging periods under three different temperatures. The material was iso-thermally heat treated at higher temperatures than $391^{\circ}C$ that is the operating temperature of high pressure reactor vessel. Vickers hardness properties and electrical resistivity properties about artificially aged material as well as un-aged material were measured, and master curves were made out from the correlation with larson-Miller parameter. And electrical resistivity properties as well as Victors hardness properties measured at high pressure reactor vessel of the field were compared with master curves made out in a laboratory. Degradation evaluation possibility in the field of high pressure reactor vessel by using electrical resistivity method was examined. Electrical resistivity property measured in the field is similar with that of artificially aged material in similar aging level.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.687-690
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• 2009

본 연구에서는 가스 하이드레이트 형성과정에서 발생할 수 있는 유도지체시간을 줄이고 전체 가스 저장량과 반응 속도의 향상을 위하여 이류체 분사 방식을 이용하여 물분자의 액적을 최소화하는 실험을 통하여, 미세액적 분사에 따른 하이드레이트 형성 시간을 확인하였으며, 반응기 내부의 온도 변화를 확인하여 반응기 내부의 하이드레이트 형성 거동을 확인하고 이를 통하여 상용화를 위한 반응기 설계의 기초 자료로 활용하고자 하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.107.2-107.2
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• 2010

고온건식탈황기술은 고온고압에서 석탄가스에 함유된 황화합물을 제거하는 기술로 석탄가스화에 의해 생성된 고온의 석탄가스의 열손실을 최소화하여 열효율이 높은 기술이다. 본 연구에서는 석탄으로부터 합성원유를 생산하는 0.3 배럴/일 규모 석탄액화(CTL)공정의 연계운전을 통하여 건식탈황공정의 성능을 평가하였다. 0.3 배럴/일 규모 석탄액화공정은 석탄가스화기, 건식탈황공정, 액화공정으로 구성되어 있으며 30 atm의 고압에서 운전된다. 건식탈황공정은 석탄가스화기와 액화공정 사이에 위치하여 석탄가스화로부터 생성된 석탄가스에 함유된 황화합물을 아연계 건식탈황제에 의해 제거한 후 액화반응기로 공급하여 황화합물에 의한 촉매의 피독을 막아주는 역할을 수행한다. 본 연구에서는 기존에 개발된 두 개의 기포유동층 반응기로 구성된 탈황장치를 30 atm에서 운전이 가능하도록 수정/보완하여 실제 운전압력인 30 atm의 고압에서 연속운전을 수행하였다. 실험 결과 탈황효율은 99% 이상이며 탈황반응기 출구 황화합물의 농도는 1 ppmv 이하로 유지하였다.

• Journal of the Korean Chemical Society
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• v.48 no.5
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• pp.461-466
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• 2004

Kinetics for the nucleophiles have been studied under high vacuum and high pressures in various temperatures. Pseudo-first order rate constants, second order rate constants, thermodynamic parameters and Hammett ${\rho}$-values are determined. The values of ${\Delta}V^{\neq},\;{\Delta}{\beta}^{\neq}\;and\;{\Delta}S^{\neq}$are all negative. The Hammett r-values are negative for the nucleophile (${\rho}$x) over the pressure range studied. The results of kinetic studies for pressure and nucleophilet show that these reactions proceed in typical $S_N2$ reaction mechanism and change of mechanism.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.492-498
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• 2012

In this study, hydrodynamics such as solid circulation rate and voidage in the desulfurizer and the reaction characteristics of Zn-based solid sorbents were investigated using lab-scale high pressure and high temperature desulfurization process. The continuous HGD (Hot Gas Desulfurization) process consist of a fast fluidized bed type desulfurizer (6.2 m tall pipe of 0.015 m i.d), a bubbling fluidized bed type regenerator (1.6 m tall bed of 0.053 m i.d), a loop-seal and the pressure control valves. The solid circulation rate was measured by varying the slide-gate opening positions, the gas velocities and temperatures of the desulfurizer and the voidage in the desulfurizer was derived by the same way. At the same gas velocities and the same opening positions of the slide gate, the solid circulation rate, which was similar at the temperature of $300^{\circ}C$ and $550^{\circ}C$, was low at those temperatures compared with a room temperature. The voidage in the desulfurizer showed a fast fluidized bed type when the opening positions of the slide gate were 10~20% while that showed a turbulent fluidized bed type when those of slide gate were 30~40%. The reaction characteristics of Zn-based solid sorbent were investigated by different desulfurization temperatures at 20 atm in the continuous operation. The $H_2S$ removal efficiency tended to decrease below the desulfurization temperature of $450^{\circ}C$. Thus, the 10 hour continuous operation has been performed at the desulfurization temperature of $500^{\circ}C$ in order to maintain the high $H_2S$ removal efficiency. During 10 hour continuous operation, the $H_2S$ removal efficiency was above 99.99% because the $H_2S$ concentration after desulfurization was not detected at the inlet $H_2S$ concentration of 5,000 ppmv condition using UV analyzers (Radas2) and the detector tube (GASTEC) which lower detection limit is 1 ppmv.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.33-38
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• 1999

CCT(Clean Coal Technology)의 응용분야인 IGCC, PFBC 및 MCFC 등 석탄을 이용한 새로운 발전기술에 활용될 것으로 예견되는 고온건식 탈황기술은 고온(35$0^{\circ}C$~$650^{\circ}C$)과 고압(약 20기압)상태에서 금속 산화물로 된 고체흡수제(고온건식 탈황제)를 이용하여 반응기(유동층, 고속유동층 및 고정층과 이동층 반응기 등)에서 흡수와 재생반응을 통하여 석탄가스중에 있는 H$_2$S 등 황화물을 효율적으로 제거하는 기술이다.(중략)

• The Microorganisms and Industry
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• v.20 no.2
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• pp.41-45
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• 1994

실관막은 단위부피당 표면적이 커서 상과 상간의 물질전달속도를 증가시킬수 있다는 장점때문에 효소, 미생물, 동식물의 고정화 반응기로써 많은 연구가 진행되어 왔다(1,2). 실관반응기는 이러한 장점이외에도 고정화가 수월하며, 생산물과의 1차분리가 이루어지며, scale-up시 에너지 소모가 적다는 장점을 가지고 있다. 그러나, 불용성 기질을 사용할 경우, 실관막 기공의 막힘으로 인해 장시간의 조업이 어렵고, 고분자 재질 실관막의 경ㅇ, 몇몇 특수 재질을 제외하고 고온/고압 멸균이 불가능하다는 단점을 지니고 있다. 또한 반응기의 구조상 기체의 원할한 공급이 어려우므로 산소소비속도가 빠른 호기성 미생물 배양을 위해서는 이중실관막과 같은 특수설계의 실관 반응기가 이용될 수 있다(3,4). Fig. 1은 독일 Enka사의 polypropylene 실관의 단면과 전형적인 조업방식을 보여준다.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.189-193
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• 2008

In this study, the effect of reaction conditions on the transesterification of soybean oil and methanol was investigated in a high-pressure-fixed-bed-reactor-system with zinc aluminate catalysts. Without catalysts, high-pressure-reaction at $300^{\circ}C$ and 1,200 psi brought 19% yields of methyl esters, which was caused by the approach of reaction condition to supercritical point of methanol. However, except the specific reaction condition, the yields in the reaction with no catalyst were very low below 4.5%. The zinc aluminate was prepared as catalyst by coprecipitation and characterized with $N_2$ gas adsorption/desorption and X-ray diffraction. With catalyst, the effect of the reaction parameters such as temperature, pressure, and molar ratio of reactants on biodiesel production was demonstrated. The higher temperature, pressure, and methanol molar ratio to soybean oil, the more yields of methyl esters. It was proved that among the reaction parameters, the reaction temperature be the most influential variable on methyl ester yields.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.709-714
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• 2002

To investigate the decomposition kinetics of poly(ethylene terephthalate) the high pressure molten-polymer injector has been devised. Using the experimental apparatus equipped with batch reactor and high pressure molten-polymer injector the decomposition of PET has been performed at constant pressure of 250 bar and 300, 320, $340^{\circ}C$, respectively. At each temperature conditions the conversions after initial 1 minute have shown very high values such as 76-90%. As the temperature increases the conversion reaches more than 98% at 10 minutes. Based on the second order reaction model the reaction rate constants have been obtained. We can calculate the conversions within 2% errors utilizing optimized rate constants. The activation energy for the decomposition of PET at subcritical conditions has shown to be 54.4 kJ/mol.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.117-118
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• 2010

본 논문은 저온플라즈마를 이용한 탈황탈질 시스템에서 고압펄스압축을 위해 사용되는 자기스위치의 자동제어방법에 관한 것이다. 자기스위치를 부하변동에 따라 자동제어 함으로써 플라즈마 반응기에 전달되는 에너지의 전달효율을 최적화 시킬 수 있다.