• 한국응용과학기술학회지
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• 제27권1호
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• pp.6-13
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• 2010

Esterification reaction between succinic acid and 1,4-butanediol was kinetically investigated in the presence of nontoxic organometallic compound catalyst(ESCAT-100E) at $150-190^{\circ}C$. The reaction rates measured by the amount of distilled water from the reaction vessel. The Esterification reaction was carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd. The linear relationship was shown between apparent reaction rate constant and reciprocal absolute temperature. By the Arrhenius plot the activation energy have been calculated as 376.13 kJ/mol under nontoxic organometallic compound catalyst and also apparent reaction rate constant, k' was found to obey first kinetics with respect to the concentration of catalyst.

• 한국응용과학기술학회지
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• 제26권3호
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• pp.362-369
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• 2009

Esterification reaction between succinic acid and 1,4-butanediol was kinetically investigated in the presence of monobutyl tinoxide catalysts at $150{\sim}190^{\circ}C$. The reaction rates measured by the amount of distilled water from the reaction vessel. The esterification reaction was carried out under the first order conditions with respect to the concentration of reactants, respectively. The overall reaction order was 2nd. The linear relationship was shown between apparent reaction rate constant and reciprocal absolute temperature. By the Arrhenius plot the activation energy have been calculated as 87.567 kJ/mol under monobutyl tinoxide catalyst and also apparent reaction rate constant, k' was found to obey first kinetics with respect to the concentration of catalyst.

• 한국환경과학회지
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• 제13권1호
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• pp.79-87
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• 2004

Esterification of soybean oil with methanol was investigated. First of all, liquid-liquid equilibriums for systems of soybean oil and methanol were measured at temperatures ranging from 40 to 65$^{\circ}C$. Profiles of conversion of soybean oil with time were determined from the glycerine content in reaction mixtures for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)$_2$, MgO, Mg(OH)$_2$, and Ba(OH)$_2$. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Esterification of waste vegetable oil with methanol was investigated and compared to the case of soybean oil. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by solid catalyst, final conversion was strongly dependent on the alkalinity of the solid catalyst, and increased with the alkalinity of the metal. Hydroxides from the alkali metals were more effective than oxides. When Ca(OH)$_2$ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4％. When CHCl$_3$ as a cosolvent, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)$_2$, maximum value of final conversion was appeared at dose of 3％. When waste vegetable oil was catalyzed by NaOH and solid catalysts, high final conversion, over 90％, and fast reaction rate were obtained.

• 공업화학
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• 제20권5호
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• pp.532-535
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• 2009

본 연구에서는 식물성 오일의 에스테르화 반응에 초음파에너지를 도입하여 지방산 methyl ester를 제조하였다. 초음파 에너지가 에스테르화 반응에 도입될 경우 반응온도의 가열효과뿐만 아니라 교반효과를 동시에 가져올 수 있어 반응시간 단축 및 지방산 methyl ester 수율의 증가를 가져올 수 있다. 그러나 초음파에너지가 에스테르화 반응에 도입될 때 연속적인 초음파에너지의 조사로 인한 반응온도의 계속적인 상승이 문제점으로 확인되었다. 따라서 본 연구에서는 cooling system을 이용하여 반응온도의 상승을 억제하여 실험을 수행한 결과 기존공정보다 빠른 30 min 만에 93%의 지방산 methyl ester 수율을 확인하였다.

• 생명과학회지
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• 제5권4호
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• pp.155-161
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• 1995

The effects of substrate concentration, enzyme concentration, reaction temperature, and water content were investigated in intramolecular esterification. This study used cyclohexane as organic solvent, power lipase as enzyme, and benzyl alcohol and octanoic acid as substrate. The initial reaction rate was found to be proportional to enzyme concentration; followed Michaelis-Menten equation for octanoic acid; and was inhibited by benzyl alcohol . The observed initial reaction rate first increased, then decreased with increasing reaction temperature, giving rise to the maximum rate at 20$\circ$. The drop in the reaction rate at higher temperature was to partition equilibrium change of substrate between organic solvent and hydration layer of enzyme molecule in addition to the deactivation by enzyme denaturation. Water layer surrounding enzyme molecule seemed to activate in organic solvent and the realistic reaction was done in the water layer. In the enzymatic reaction in organic solvent, the initial reaction rate was influenced by partition quilibrium of substrate, so the optimum condition of substrate concentration, enzyme concentration, reaction temperature, and water content would give a good design tool.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.165-170
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• 1998

Lipase-catalyzed esterification of n-butyl oleate was carried out in n-hexane as a model reaction. The optimal activity of Candida rugosa lipase was shown in a water activity ($a_w$) range of 0.52 to 0.65 at $30^{\circ}C$. The water produced from the esterification was removed by a tubular type pervaporation system. The rate of ester formed from the enzymatic esterification was allowed to be the same as the rate of water removal by maintaining an optimal $a_w$ of the reaction system using an on-off dewatering control device. The reaction rate and yield with a$a_w$ control were increased two folds higher than the respective values for the uncontrolled reaction.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3122-3124
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• 2012

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.196-201
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• 2000

Lactic acid is of interest as the raw materials of polyactide that is a biodegradable polymer. For an effective purification of acid, batch distillation with the simultaneous reactions was used. Two Oldershow colums and reboilers were usde for fractionation of methanol and reactions. Two Oldershaw columns and reboilers were used for fractionation of methanol and reactions. Esterification reaction of lactic with methanol produced methyllactate and water. The productes of the esterification reaction, methl lactate and water were transported to the reboiler of the reproysis part. In hydroduced in the hydrolysis part and nureacter method lactic acid and methanol. Methanol produced in the hydroysis part and unreacted method lactic acid and methanol in the esterification part were separated by distillation and recycled to the revoiler of the esterification part so that the esterification reaction would be stimulated. Thus, pure lactic acid solution remained in the reboiler of the hydroysis part. The effect of the number of stages in column on the recovery yield was also inverstigated. In the operation with colums improved the fractionation of componets and stimulated the reactions in two parts.

• 한국응용과학기술학회지
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• 제26권4호
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• pp.415-421
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• 2009

Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD} was kinetically investigated in the presence of organic metal catalysts (alkyl-silver oxide(ASO),CAT 100E) at $150{\sim}190^{\circ}C$. The reaction rates measured by the amount of distilled water from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculate as 146.70 kJ/mol with ASO catalyst and 43.04 kJ/mol with CAT 100E catalyst.

• 한국응용과학기술학회지
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• 제28권1호
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• pp.22-28
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• 2011

Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD] was kinetically investigated in the presence of organometallic catalysts (ESCAT-100Ag18, MBTO) at $150{\sim}180^{\circ}C$. The reaction followed from the measurement of the quantity of water which was distilled from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculated as 146.70 kJ/mol(ESCAT-100Ag18) and 87.57 kJ/mol(MBTO), respectively.