http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
금속담지촉매상의 에틸렌의 수소화반응에서 속도다중성에 대한 연구
한도흥 嶺南大學校 工業技術硏究所 1989 연구보고 Vol.17 No.2
Ethylene hydrogenation experiments were carried out respectively over 0.01wt.% pt/?? -Al₂O₃and 0.05wt.% pt/α-Al₂O₃ catalysts and rate multiplicity including ignition and extinction points was found. Over 0.01 wt.% pt/?? -Al₂O₃catalyst, the width of rate-concentration hysteresis loop increased with hydrogen concentration, but above some hydrogen concentration the extinction point abruptly increased and existed at very high ethulene concentratoin. Over 0.05wt.% pt/α-Al₂O₃, extinction points were found on the decreasing path of ethylene concentration but ignition points could not be found on any path. The difference between feed temperature and catalyst layer temperature is small at a narrow width and much large at a very wide width. This result suggests that the multiplicity in ethylene hydrogenation may be caused by the coupling effect of kinetic and heat transfer limitation.
반경흐름 고정층 반응기의 해석 : Ⅰ.내경에 대한 외경의 비의 영향 Ⅰ.Effect of ratio of the inner radius to the outer one.
韓道興 嶺南大學校 工業技術硏究所 1982 연구보고 Vol.10 No.2
This paper examines the effect of ratio of the inner radius to the outer one ξ₁ on the conversion of isothermal single reaction in a radial flow fixed-bed reactor. The velocity of reactant gas is only related to ξ₁at the given feed condition and catalyst volume, so that the conversion of radial flow fixed bed is affected by the values of ξ₁. The results of exact and numerical analysis show that lower values of ξ₁ give higer conversion for the positive reaction order and lower conversion for the negative ones, but the values of ξ₁ have no effect on the conversion for the zeroth order reaction or in the plug flow reactor.
에틸렌 수소화 반응에서 다중성의 존재 가능성에 대한 이론적 연구
한도흥,박오옥,김영걸 ( Do Hung Han,O Ok Park,Young Gul Kim ) 한국화학공학회 1994 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.32 No.6
The possible existence of multiplicity features, including ignition and extinction phenomena, is theoretically examined for ethylene hydrogenation in the kinetic region with the exclusion of heat and mass transfer limitations, and then the ethylene hydrogenation is compared with CO oxidation for which it has been claimed in several studies that multiple steady states can come from a purely kinetic process. From both theoretical and numerical analyses, it is concluded that if each chemisorbed ethylene occupies less than two active sites of catalyst more strongly than hydrogen the multiple steady states can exist, but the multiplicity features can not be obtained if an ethylene molecule adsorbs strongly upon more than two active sites. From our experiment and another studies for chemisorptions, it is confirmed that the chemisorption of ethylene requires geometrically 3-4 active sites per each molecule and that is much more strong than one of hydrogen. Therefore, the existence of kinetically induced multiplicity will not be possible for ethylene hydrogenation. On the other hand, the kinetically induced multiplicity for CO oxidation will arise from the fact that carbon monoxide chemisorbs more strongly than oxygen upon less than two active sites. In our study, it is found that the number of geometrically occupied active sites rather than the chemical bonding number in the chemisorption of reactants might exert an important influence on the existence of the multiplicity features in the reaction proceeding via Langmuir-Hinshelwood mechanism.
한도흥 嶺南大學校 工業技術硏究所 1989 연구보고 Vol.17 No.2
Numerical examples show that clock wise hysteresis loop can exist in the hydrogenation of ethylene over pt catalyst when one molecule of ethylene is chemisorbed on one atom of platinium, but rate multiplicity cannot be found when one molecule of ethylene is chemisorbed associatively on two atoms of platinium. Also numerical analysis shows that rate multiplicity can exist in the case of associative adsorption of ethylene on the two site of platinium by considering hydrogen spillover to support.
양해영,한도흥,하병환 嶺南大學校 工業技術硏究所 1994 工業技術硏究所論文集 Vol.22 No.2
Sustained oscillation, including a constant amplitude of less than 10℃ in temperature and a short period between several seconds and several minutes, was experimentally found in the CO oxidation over fixed bed of platinium/γ-alumina catalysts. From this study, it was believed that the oscillation could occur within the kinetic region in exclusion of heat transfer limitation. On the other hand, under some more strong heat transfer limitation,the temperature-oscillation had a long period of several ten minutes and two types of concentration-oscillation, which periods were short and long, could simultaneously exist at one period. Finally, under a strong heat transfer limitation, the oscillation disappeared but rate-multiplicity phenomenon only appeared.
循環 흐름을 가진 固定層 反應器의 不安定性에 관한 硏究
梁海永,韓道興,李明浩 嶺南大學校 工業技術硏究所 1993 工業技術硏究所論文集 Vol.21 No.1
In this study we observed the possible existence of multiple steady states for CO oxidation over Pt/Boehmite catalysts, which is one of instabilities, and also analyzed numerically these phenomena with some proper reactor models. The form of our reactor was a non-adiabatic fixed bed with recycle. The reactor models include both one phase model with plug flow and two phase model with heat transfer resistance between gas phase and solid one. Especially, it was attempted to explain the multiplicity features with a very wide region, whose features could not have been clearly explained by means of any other model, by the modified two phase model which includes a term related with memory effect of catalyst temperature. The experiments showed that the effect of recycle ratio on multiplicity region could not be revealed definitely for our experimental conditions. This may arise from the facts that the multiplicity for the CO oxidation over Pt/Boehmite cataysts resulted mainly from strong heat transfer limitation rather than from mixing effect related with recycle flow since the CO oxidation was a reaction with both very high generation and rapid reaction rate.