• 한국환경과학회지
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• 제18권2호
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• pp.231-238
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• 2009

Characteristics of the transesterification reaction between triglycerides in soy bean oil and methanol were investigated in the presence of acid catalysts. such as sulfuric acid and PTS (p-toluene sulfonic acid). Concentrations of diglyceride and monoglyceride which were intermediates in the reaction mixtures, were far below 10% of triglyceride under any reaction conditions. Thus, conversion of the reaction could be determined from the concentration of triglyceride. Dried PTS had more superior catalytic power than sulfuric acid for transesterification reaction between soy bean oil and methanol. When transesterification reaction of soy bean oil was catalyzed by 1 wt% of PTS at methanol stoichiometric mole ratio of 2 and $65^{\circ}C$, final conversion reached 95% within 48 hours. If FAME (fatty acid methyl ester) was added into reaction mixture of soy bean oil, methanol and PTS catalyst, it converted reaction mixture into homogeneous phase, and substantially increased reaction rate. When reaction mixture was freely boiling which had equal volumetric amount of FAME to soy bean oil, methanol stoichiometric mole ratio of 2 and 1 wt% of PTS, final conversion achieved value of 94% and temperature approached to $110^{\circ}C$ within 2 hours.

• 한국응용과학기술학회지
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• 제10권1호
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• pp.23-29
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• 1993

Transesterification reaction between dimethyl phthalate and ethylene glycol was kinetically investigated in the presense of various metal nitrate catalysts at $170^{\circ}C$. The reaction rates measured by the amount of distilled methanol from the reaction vessel. The transesterification reaction was carried out under the first order conditions respect to the concentration of dimethyl phthalate and catalyst, respectively. The over all order was 2nd. By Arrhenius plot, the activation energy was calculated as 17.4kcal/mole and 17.2kcal/mole on the transesterification reaction with zinc nitrate and lead nitrate, respectively. Apparent rate constant, k' was appeared linear about concentration of catalyst.

• 한국응용과학기술학회지
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• 제9권2호
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• pp.141-148
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• 1992

Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at $120{\sim}170^{\circ}C$ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.103-111
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• 2018

본 연구에서는 PET (Poly Ethylene Terephthalate)의 단량체인 BHET (bis (2-Hydroxyethyl) Terephthalate)와 1,4-BD(1,4-Butanediol)의에스테르교환반응을활용하여 PBT (Poly Butylene Terephthalate)의단량체인 BHBT (Bis (4-Hydroxybutyl Terephthate)를 생성하는 반응에 대하여 조사하였다. 이 반응의 촉매로 Zinc Acetate를 사용하였다. 회분식 반응기를 통하여 BHET, EG (Ethylene Glycol), THF (Tetrahydrofuran)의 양을 정량하여 반응 kinetics 모델을 구성하였다. 제시된 모델을 통하여 반응속도와 반응물의 조성 분포를 조사하였고, 이 모델의 예측 값과 실험 값들이 잘 일치함을 보였다.

• 미생물학회지
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• 제33권3호
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• pp.181-186
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• 1997

유기용매계에서 lipase AK를 사용하여 당 ester화합물을 합성하였다. 유기용매로는 당의 용해도가 높고 반응성이 뛰어난 pyridine을, acyl donor로는 vinyl butyrate을 선택하였다. Transesterification반응에 의해 생성된 monobutyryl fructose와 dibutyryl fructose는 TLC 및 GC 분석으로 확인하였다. Transesterification에 미치는 반응조건은 fructose:vinyl butyrate의 비가 1:10(M/M), 반응온도 40^{\circ}C.$, 교반속도 150rpm, 효소량 10mg/ml의 경우가 적당하였으며 반응시간이 길어질수록 전환율이 높아져, 반응 10일 정도에서 전환율은 90% 이상에 도달하였다. 이때 반응 초기에는 monobutyryl fructose가 주로 합성되었으나 시간이 경과함에 따라 dibutyryl fructose의 함량비가 증가하였다. 반응계에 소량의 수분을 첨가하였을 경우에는 반응속도가 감소함과 동시에 반응산물중 dibutyryl fructose의 양은 줄어들고 monobutyryl fructose의 생성량이 증가하는 경향을 보여주었으며, 수분함량 1%에서는 monobutyryl fructose만이 생성되었다.

• Advances in environmental research
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• 제1권3호
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• pp.191-199
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• 2012

A kinetic study of the transesterification of soybean oil was conducted using microwaves under various temperatures, power densities, and reaction times. Results show that power density affects the kinetics and yield. The biodiesel yield increased with increasing microwave power density. The non-thermal effects of microwave irradiation on transesterification reactions were evaluated at a constant reaction temperature ($65^{\circ}C$) and power density (0.204 $Wg^{-1}$). Microwave irradiation was found to increase the reaction rates by 3.52-7.06 fold.

• Korean Chemical Engineering Research
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• 제56권3호
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• pp.416-420
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• 2018

A comprehensive kinetic study has been conducted on dimethyl carbonate synthesis by transesterification reaction of ethylene carbonate with methanol. An alkali base metal (KOH) was used as catalyst in the synthesis of DMC, and its catalytic ability was investigated in terms of kinetics. The experiment was performed in a batch reactor at atmospheric pressure. The reaction orders, the activation energy and the rate constants were determined for both forward and backward reactions. The reaction order for forward and backward reactions was 0.87 and 2.15, and the activation energy was 12.73 and 29.28 kJ/mol, respectively. Using the general factor analysis in the design of experiments, we analyzed the main effects and interactions according to the MeOH/EC, reaction temperature and KOH concentration. DMC yield with various reaction conditions was presented for all ranges using surface and contour plot. Furthermore, the optimal conditions for DMC yield were determined using response surface method.

• 한국응용과학기술학회지
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• 제4권1호
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• pp.67-71
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• 1987

The transesterification reaction between diethanolamine and methyl methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $120^{\circ}C$. The amount of reacted methyl methacrylate was measured by gas chromatography and liquid chromatography, and the reaction rate also measured from the amount of reaction products and reactants under each catalyst. The transesterification reaction was carried out in the first order with respect to the concentration of diethanolamine and methyl methacrylate, respectively. The over-all order is 2nd. The apparent rate constant was found to obey first-order kinetics with respect to the concentration of catalyst. The maximum reaction rate was appeared at the range of 1.4 to 1.6 of electronegativity of metal ions and instability constant of metal acetates.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.164-168
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• 2003

유채유를 사용하여 바이오디젤 생산을 위한 1단 전이에스테르화 공정에 있어서 반응온도 $60^{\circ}C$, 유지에 대한 메탄올 몰비 1:10 이상, 1.0 % (w/w) 포타슘 하이드록시드의 조건에서 98.5% 이상의 전화율을 얻을 수 있었다.

• 한국응용과학기술학회지
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• 제7권1호
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• pp.71-76
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• 1990

Transesterification reactions (methyl methacrylate with monoethanolamine, methyl methacrylate with n-butyl alcohol, dimethylphthalate with ethylene glycol, dimethyl phthalate with monoethanolamine) were kinetically investigated in the presense of various metal acetate catalysts at $110^{\circ}C$. The amount of reactants was measured by gas and liquid chromatography, and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd, Maximum reaction rates were appeared at the range of 1.4 to 1.6 in electronegativity of metal ions and maximum catalytic activities were obserbed at the range of 1.5 to 1,8 in instability constant of metal acetates.