• 한국식품영양과학회지
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• 제28권5호
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• pp.980-983
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• 1999

The contents of sterols and stanols in vegetable oils and mist oil were analyzed by gas chromatography using a capillary column. The total sterol contents showed high values of 0.67~0.89g/100g in corn oil, rice bran oil, red pepper seed oil and sesame oil. Mist oil, a byproduct of soybean oil manufacture, was a suitable raw material for the production of stanol since it showed high sterol content (10.2g/100g). In the hydrogenation of sterol contained in mist oil using Pd catalyst, the effects saponification of oil were examined. The conversion of sterol to stanol was improved by a factor of 4~5 through saponification of oil, compared to the reaction without saponification.

• 한국식품과학회지
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• 제27권1호
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• pp.41-46
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• 1995

Changes of fatty acid composition and reaction rate were investigated according to reaction condition during partial hydrogenation reaction of soybean oil until its iodine value decreased from 134 to 110. The reaction conditions were varied in the range of from $170^{\circ}C$ to $210^{\circ}C$ of temperature, from 1.3 atm to 4.2 atm of pressure and from 0.005% to 0.1% of nickel concentration as catalyst. Lecithin was added in soybean oil to investigate the change of reaction rate. The result of addition of lecithin showed that reaction rate decreased to from 2 to 6 times in comparison with non-additive system.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.843-846
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• 2004

Pt nanoparticles loaded on alumina through an impregnation at room temperature was prepared using $K_2PtCl_4$ and acrylic acid as capping material. Transmission electron microscopy showed that the deposited Pt particles indicate ca. 80% cubic shapes with a narrow distribution of 8-10 nm in size. Propylene hydrogenation over the catalyst has been carried out to evaluate their catalytic performance by the values of activation energy. It is determined from the initial rate, reaction order, and rate constant and is found to be $9.7{\pm}0.5$ kcal/mol. This value has been discussed by comparing to those of encapsulated- and truncated octahedral Pt nanoparticles deposited on alumina, respectively, to study influence of the particle size and shape, and capping material used on the activation energy.

• 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.

• 한국산학기술학회논문지
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• 제7권4호
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• pp.715-720
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• 2006

CO와 유사한 분자궤도함수를 갖는 isocyanide 리간드가 포함된$Cp(CO)_{2}(L)MH$ (L = t-butylisocyanide and 2,6-dimethylphenylisocyanide M = Mo and W)를 합성하고, 이 착물과 triflic acid를 사용하여 카르보닐기를 알코올로 전환시키는 실험을 하였다. 또한, 이들 착물을 촉매 전구체로 이용하여 3-pentanone의 수소화 반응을 온화한 조건 ($23^{\circ}C,\;<4.1\;atm H_{2}$)에서 수행하였다. 촉매 활성은 매우 낮았으며, [$Cp(CO)_{2}(ArNC)Mo][BA_{r}^{F}_{4}$]의 경우에 2 turnovers/day의 결과를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.360-362
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• 1989

Catalytic isomerization of unsaturated alcohols to the corresponding carbonyl compounds with$Rh(ClO_4)(CO)(PPh_3)_2\;(1)\;and\;[Rh(CO)(PPh_3)_3]ClO_4$ (2) is faster under hydrogen (where hydrogenation also occurs to give saturated alcohols) than under nitrogen. The isomerization under hydrogen seems to occur through an alkylhydridorhodium(III) complex which also undergoes reductive elimination to give hydrogenation products, saturated alcohols. The isomerization under hydrogen is faster with 2 than with 1, which is understood by acceleration of the last step, enol formation by $PPh_3$ dissociated from 2 and present in the reaction mixture when 2 is used as catalyst. Relative rates of the isomerization observed for different unsaturated alcohols are interpreted by steric effects of substituted groups and numbers of hydrogens to be abstracted by the rhodium of the intermediate, alkylhydridorhodium(III) to undergo the reductive elimination to give enol which is then rapidly converted into a carbonyl compound. It has been observed that the hydrogenation is relatively significant when reactions occur slowly whereas the isomerization is predominant when reactions proceed rapidly.

• 한국응용과학기술학회지
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• 제27권3호
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• pp.273-281
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• 2010

Nickel recovery method was studied by the wet process from the catalyst used in hydrogenation process. Nickel content in waste catalyst was about 16%. At the waste catalyst leaching system by the alkaline solution, selective leaching of nickel was possible by amine complex formation reaction from ammonia water and ammonium chloride mixed leachate. The best leaching condition of nickel from mixed leachate was acquired at the condition of pH 8. LIX65N as chelating solvent extractant was used to recover nickel from alkaline leachate. The purity of recovered nickel was higher than 99.5%, and the whole quantity of nickel was recovered from amine complex.

• 공업화학
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• 제5권3호
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• pp.509-516
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• 1994

에탄올의 제조시 불순물로서 미량 생성되는 크로톤 알데히드를 수소와 반응시켜 n-부틸알콜로 전환하여 불포화 탄화수소를 제거하는 공정에 액상수소 첨가반응을 이용하고자 하며, 기존의 기상 수소첨가반응보다 월등한 에너지 절약 효과가 있다. 반응촉매는 내구성 및 가격 등 경제적인 측면을 고려하여 니켈촉매를 선택하였으며, 반응전화율의 측정은 PMT(permanganate time) test 방법을 적용하였다. PMT는 에탄올에 미량으로 함유되어 있는 크로톤알데히드의 초기농도 증가에 따라 급격히 감소하였으며, 크로톤 알데히드로부터 n-부틸알콜로의 수첨반응은 탄소-탄소 이중결합의 환원 후, 알데히드의 환원 과정이 연속적으로 일어나고, 각 반응단계는 0차 반응속도 상수를 가진다. 실험조건 범위 내에서는 반응 온도가 높을수록, LHSV가 느릴수록 PMT는 길어지고, 반응압력은 PMT와 거의 무관함을 보였다.

• 공업화학
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• 제2권1호
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• pp.38-46
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• 1991

탄소 침적과 황피독된 수소 첨가용 Ni 촉매의 재생에 관하여 연구하였다. 탄소 침적된 촉매를 수소로 재생할 경우, 재생율은 높았으나 재생 시간이 길었으며 침적된 탄소가 완전히 제거되지 않았다. 산소로 재생할 경우에는 재생시간이 단축되었고 대부분의 침적된 탄소를 제거시킬 수 있었으나 반드시 환원과정이 뒤따라야 한다는 문제점이 있었다. 황에 완전히 피독된 촉매를 수소와 수증기만으로 재생 처리할 경우 활성의 회복을 기대할 수 없었으나, 산소가 포함된 재생처리에는 $650^{\circ}C$에서 활성이 60 %까지 회복되었으며, HCl이 첨가된 경우에는 특히 저온에서 활성이 45 %정도까지 회복되었다. 수증기는 촉매의 소결현상을 촉진시키나, 산소 또는 염소는 소결억제 효과가 있는 것으로 나타났다.

• KSBB Journal
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• 제16권1호
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• pp.76-81
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• 2001

Stigmastanol, a functional agent of cholesterol-lowering in humans, was synthesized from stigmasterol. To investigate the usability as a raw material, the contents of sterol in vegetable oils and extract of soybean chaff were analyzed. The total sterol contents showed high values of 213.7 and 209.8 mg/100g in corn and soybean oils respectively. The extract of soybean chaff has played a good role as a raw material with high sterol contents. The kinetics of hydrogenation of stigmasterol was studied using a 5% Pd/AC catalyst in the temperature range of 30~$60^{\circ}$C. Increasing temperature showed a prominent decrease in conversion. The optimum temperature was $40^{\circ}$C for high yield of stigmastanol. The effects of $H_2$ pressure, agitation speed, catalyst loading, and stigmasterol concentration on reaction rate profile were also examined. From the power law model analysis using the initial rates of reaction, the reaction order was calculated as 0.705 for stigmasterol concentration and 0.147 for hydrogen pressure.