• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1659-1664
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• 2014

A porous metal-organic framework (MOF), MIL-101, was synthesized in the presence of sulfated zirconia (SZ) to produce acidic SZ/MIL-101 composites for the first time. The composites were characterized with XRD, nitrogen adsorption, FT-IR, scanning electron microscope, chemical analysis and so on. The composites (SZ/MIL-101s) were successfully applied in a liquid-phase esterification for a high yield of ester. This catalytic result of SZ/MIL-101, compared with that of pure SZ or MIL-101 (showing a negligible yield of ester), suggests that the SZ in the composite is highly active in the acid catalysis probably because of the well-dispersed active species of SZ. Moreover, the esterification is catalyzed in heterogeneous mode as confirmed by negligible esterification after filtration of the catalyst. Finally, microwaves can be efficiently applied both in the synthesis of the composites and the esterification reaction to accelerate the two processes of synthesis and esterification by about 5 times.

• 공업화학
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• 제24권1호
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• pp.72-76
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• 2013

본 연구에서는 norbornene 디에스터 유도체를 합성하는 공정에서 반응 부산물로 생성되는 boric acid를 회수하여 norbornene diacid의 에스터화 반응에 재사용 가능성을 조사하였다. Boric acid를 4가지의 alcohol과 에스터화 시켜 4종류의 trialkyl borate (tributyl borate, tripentyl borate, triisopentyl borate, trihexyl borate)를 합성한 다음 이를 norbornene dicarboxylic acid와 반응시키는 2단계 공정으로 디에스터 유도체를 합성하였다. 이 때 norbornene dicarboxylic acid의 전환율은 89.50~99.31%였다. 디에스터화 반응의 부산물인 boric acid를 NaCl염과 함께 회수하여 trialkyl borate를 합성한 후 정제한 결과 회수율은 92.43~99.35%이었다. 이를 다음 반응에 사용한 결과 디에스터의 수율은 43.70~64.39%였고 순도 97.70~99.24%로 수율이 일부 감소되었으나 손실이 크지 않음을 확인하였다. 주요 반응 부산물인 boric acid를 공정내에서 재사용이 가능하므로 화합물 배출에 의한 환경오염을 사전에 예방할 수 있는 친환경공정으로 적용 가능함을 확인하였다.

• 한국분무공학회지
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• 제14권3호
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• pp.117-121
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• 2009

Biodiesel fuel has different spray patterns, because viscosity and surface tension of biodiesel fuel are higher than that of diesel fuel. The diesel combustion is strongly controlled by the fuel spray behavior in combustion chamber. So, it was needed to understand the spay characteristics of non-esterification biodiesel fuel. In this study, the spray characteristics of non-esterification biodiesel fuel was investigated to confirm of an effect of WDP. The characteristics of fuel atomization was analyzed with SMD and span factor through laser diffraction particle analyzer (LDPA), and the process of spray injection was visualized through the visualization system composed of a halogen lamp and high speed camera. It was found that injection delay time and SMD of blended fuel with WDP get shoter and smaller than that of non-esterification biodiesel fuel.

• 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.

• 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.

• 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.

• 펄프종이기술
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• 제46권6호
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.

• 한국인쇄학회지
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• 제16권2호
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• pp.61-74
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• 1998

Some photopolymer, poly(vinyl cinnamoyl acetate)(PVCiA) was synthesized by esterification of polymer(vinyl alcohol)(PVA) with monochloroacetic acid, followed by reaction poly(vinyl monochloroacetate)(PVAhA) and potassium cinnamate. When esterification of PVA with monochloroacetic acid was reacted in the dimethyl sulfoxide(DMSO), in the synthesis of PVChA, it is very good yield and the successive cinnamoyl acetoxyl esterification of PVCiA can be successfully synthesized. But PVCiA is low photosensitive polymer if net added photosensitizing dyes. Here, we synthesized photosensitizing dyes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.582-588
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• 1993

A scheme of dynamic optimization for batch reactor his been developed and applied to a semi-batch esterification reactor. To obtain optimal operating conditions for the given semi-batch reactor system with complex reaction kinetic and process constraints, a general nonlinear programming solver and finite element techniques have been introduced. The optimization results for the complex reactor system have been compared with those of Kumar et al. [1984] to show better optimization performance. The proposed optimizing scheme has been applied to the free end time problem to obtain the realistic operating condition. The results can supply valuable information for economic operation of the given batch esterification reactor.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.524-528
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• 2012

A kind of nanosized sulfated zirconia was prepared by a hydrothermal method, and full characterized by XRD, TEM, BET, TGA, and FTIR. Its catalytic activity was evaluated in the esterification reactions, including the testing of the catalytic reusability and the optimization of reaction conditions. The obtained catalyst was revealed to be highly efficient solid catalyst for the esterification of acetic acid with n-butanol, presenting the advantages of high conversion and selectivity, easy recovery, and steady reusability.