• 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.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2001년도 춘계 학술발표회 논문집
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• pp.125-128
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• 2001

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.297-302
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• 1999

Simultaneous saccharification and fermentation (SSF) experiments were carried out with a lignocellulosic biomass. The effects of temperature on enzymatic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 g/g, which was increased by 67％ or higher over the saccharification at 42℃. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate, and separation coefficient, related to the SSF combined with membrane system (semi-batch system). When the fermentation was operated in a semi-batch mode, the efficiency of the enzymes and yeast lasted three times longer than in a batch mode.

• 한국미생물·생명공학회지
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• 제11권1호
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• pp.33-38
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• 1983

에타놀을 생산하는 Flocculent 균주는 균체순환을 위한 외부적인 장치 없이도 발효조 내부 자체에서 고농도의 균체를 유지시킬 수 있는 장점이 있다. 본 연구에서는 Flocculation 특성을 가지고 있는 Saccharomyces uvarum을 사용하여 Glucose 배지에서 회분식 및 연속식 발효특성을 고찰하였고 에타놀 발효의 수학적 모델을 만들었다. 이를 이용하여 여러 온도 및 pH에 따른 발효특성을 비교 검토한 결과 균체성장과 에탄올 생산의 최적온도는 33~35$^{\circ}C$ 이었고 pH 에 대한 영향은 그리 크지 않았으나 pH5가 최적 조건이었다. 이러한 환경적 최적 조건하에서 Semi-batch 발효에 의한 에타놀 최고 생산성은 12g/$\ell$/h이었다.

• Korean Chemical Engineering Research
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• 제55권3호
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• pp.341-352
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• 2017

부틸 아세테이트는 반응증류탑에서 초산과 부탄올의 에스테르 교환반응에 의해 제조된다. 공비첨가제는 반응영역에서 생성물인 물을 보다 효과적으로 분리할 수 있도록 하여, 반응증류탑의 성능을 향상시킨다. 중소 공장에서 회분식 공정은 연속공정에 비해 보다 유연하게 사용할 수 있다는 점에서 유리하다. 본 연구에서는 부틸아세테이트 합성을 위한 회분식 반응증류 공정과 반회분식 반응증류 공정에 대하여 공정 모사 및 실험을 통하여 연구하였다. 공정 성능 향상을 위하여 공비첨가제 종류, 공정구조에 대하여 조사하였다. 또한 반회분식 반응 증류탑을 연속 운전하여 새로운 순환 운전 방법을 제시하였으며, 이 조업 전략을 사용하여 높은 생산성과 안정한 조업이 가능함을 보였다.

• Elastomers and Composites
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• 제46권1호
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• pp.60-69
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• 2011

[ $2.1\;{\mu}m$ ]입자경의 단분산 PBA seed를 이용한 2단계 분산중합을 seeded batch process 와 seeded semi-continuous process를 이용하여 다양한 형태의 PBA/PMMA composite 미립자를 제조하였다. Batch process의 경우 PBA/PMMA composite 입자의 모폴로지는 중합 분산매인 methanol/water 비와 중합 2단계에서의 PBA seed/MMA단량체의 비에 따라 크게 영향을 받으며, methanol/water 중합분산매중 물의 량이 증가함에 따라, 그리고 중합 2단계에서 MMA단량체량이 증가함에 따라 PBA와 PMMA간의 상분리현상이 심화되어 구형의 입자로부터 egg, snowman, confetti, peanut와 같은 비구형의 PBA/PMMA composite 입자들이 제조되었다. Semi-continuous process의 경우 단량체 부가시간을 조절함으로서 PBA/PMMA composite 입자의 모폴로지가 변함을 발견하였고 특히, 단량체의 결핍된 조건하에서 구형의 PBA(코어)/PMMA(쉘) composite 라텍스가 제조되었다.

• Macromolecular Research
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• 제16권4호
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• pp.293-302
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• 2008

In our previous publication, the problem of particle deformation and coagulation at the nucleation stage in the presence of cross-linker was intensely studied by seeded batch dispersion polymerization of methyl methacrylate (MMA). In the present work, highly cross-linked, monodisperse PMMA particles were prepared under various reaction conditions by seeded semi-continuous process. Monodisperse, $6.5{\mu}m$-diameter PMMA particles containing up to 8 wt% of DVB or EGDMA were successfully made by seeded semi-continuous process and multi-semi-continuous addition process, respectively. Therefore, this study shows that seeded semi-continuous process is more effective and efficient to prepare highly cross-linked, monodisperse particles than non-seeded and seeded batch processes.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권2호
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• pp.123-129
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• 2000

A high cell density culture system for the anchorage dependent CHO cells was developed based on the combination of in removal of ammonium ion and microcarrier culture system, and semi-fed-batch feeding of glucose and glutamine was employed to the developed culture system. The glass bead was selected as an optimum microcarrier in terms of cell growth. An ammonium ion selective zeolite, Phillipsite-Gismondine, was packed in a dialysis menium ion. The semi-fed-batch operation was employer to the novel culture system for the high density cell culture, and the results showed the cell growth was improved by 32% and tPA productivity by 250%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.79-82
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• 2006

Fueled by ballooning oil prices, waste plastics are now regarded as being cheap and abundant renewable sources, removing their stigma of dirty wastes Catalytic pryolysis of plastics in liquid phase allows recovery of light fuel oil as well as green treatment of polymerics wastes, and therefore significant efforts have been devoted to this research field. In this study, catalytic Pyrolysis of LDPE was carl ied out in semi-batch reactor which equipped a unit of separation and recirculation. The effect of react ion conditions were examined by analyzing liquid oil yield and carbon number distribution of products

• KSBB Journal
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• 제13권4호
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• pp.456-460
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• 1998

Fed-batch fermentations were carried out in order to improve the efficiency of hirudin production by recombinant Saccharomyces cerevisiae. A fed-batch fermentation done with the optimized semi-synthetic medium resulted in a maximum hirudin concentration of 342mg/$\ell$ by keeping a galactose concentrations between 10 and 30g/$\ell$ which corresponded to a 11.4-fold increase in hirudin concentration compared with the simple bach fermentation done with the same medium. Comparison of the chromatographic pattern of proteins in the growth medium clearly showed that the use of the semi-synthetic medium is more advantageous for separation of hirudin than the case o fusing the complex medium. Continuous cell recycle fermentation done at dilution rate of 0.1h-1 and an inlet galactose concentration of 100g/$\ell$ yielded a maximum hirudin productivity of 19.1mg hirudin/$\ell$$.$h.