• Applied Chemistry for Engineering
• /
• v.16 no.3
• /
• pp.403-407
• /
• 2005

Pyrolysis of methyl ricinoleate, from castor oil, was performed to produce methyl undecenoate. Methyl undecenoate has excellent deodorant, bactericidal and fungicidal activity. The object of this study was to find the optimum temperatures to maximize the yield of methyl undecenoate. The optimum temperatures were at $500^{\circ}C$ and $590^{\circ}C$ for preheating and pyrolysis, respectively. The maximum yield was 46% on the basis of injected methyl ricinoleate. The feeding rate of methyl ricinoleate mixture was selected as the scale-up factor. Maintaining the maximium yield, the feeding rate was scaled-up 20 folds, while the reactor was scaled-up 18 times.

• Microbiology and Biotechnology Letters
• /
• v.20 no.5
• /
• pp.588-596
• /
• 1992

The fermentation characteristics of ethanol production by the use of immobilized Zymomonas mobilis KCTC 1534 cells were investigated in terms of formation factors such as substrate and product concentration. In batch fermentation, the maximum values of specific ethanol productivity, specific substrate uptake rate, ethanol yield, and glucose conversion rate were $29.14g/{\ell}{\cdot}h$, $60.24g/{\ell}{\cdot}h$, 0.48g/g, and 98.4%, respectively, with 17% glucose medium, and its ethanol productivity was $2.91g/{\ell}{\cdot}h$ in the case of 25 hour fermentation time. Repeated batch fermentation was possible for 30 days with 2.24-$2.94g/{\ell}{\cdot}h$ ethanol productivity. In semicontinuous fermentation, the maximum ethanol productivity was shown to be $15.7g/{\ell}{\cdot}h$ at $0.36h^{-1}$ effective dilution rate with 17% glucose concentration. In this case, ethanol yield coefficient and glucose conversion rate were 0.39 g/g, 64.7%, respectively.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.70.2-70.2
• /
• 2010

고순도 금속규소는 반도체, 태양전지 및 규소화 화합물 등의 원료로 사용되어왔으며, 최근 태양전지 시장 확대로 인해 고순도 금속규소의 수요가 증가하고 있다. 그러나 전량 수입 중인 고순도 금속규소의 수급 안정성과 품질 균일성 등이 문제가 되고 있어, 고순도 생산 공정 및 생산 에너지를 절감 공정에 관한 연구 개발이 필요한 실정이다. 이에 본 연구에서는 금속규소의 원료인 규석(SiO2)과 카본(C)의 환원반응을 온도와 압력별로 살펴보고, 평형 상태의 금속규소수율 조건을 알아보았다. 그리고 아크로 내부 위치에 따른 산화/환원 반응식을 고찰하여 주요 반응식의 깁스 자유 에너지를 비교 분석 하였다. 본 해석을 통한 실험용 아크로 제작과 기초실험을 통해 금속 규소 생산 수율 및 순도를 평가하였으며, 생산된 실리콘의 최대 순도는 약 99.8%로 측정되었다.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.268-272
• /
• 2003

Experiments were carried out to investigate the selection of industrial medium and optimization of fermentation process for the production of erythritol by Candida magnoliae SR101. In the batch fermentation, light steep water(LSW) was the best nitrogen source for the industrial production of erythritol. For the optimization of culture condition, the batch culture was performed. When the concentration of LSW was 65 mL/L in the defined medium containing 250 g/L of glucose, 44% of erythritol yield with 110 g/L of erythritol concentration and 0.66 g/L-hr of productivity, respectively were obtained. Two-stage fed-batch culture was performed to improve the volumetric productivity of erythritol. High density cell culture in the growth stage was performed by batch type with 100 g/L glucose and 500 mL/L LSW concentration, respectively. The cell yield was 0.72 g-cell/g-glucose. Productivity of erythritol was increased and concentration of organic acids such as gluconic acid and acetic acid were decreased when initial pH of 6.5 controlled by 28% ammonia water For increasing yield of erythritol, glucose concentration in the production stage was tested. 37% of total erythritol yield with 186 g/L of erythritol concentration and 1.66 g/L-hr of erythritol productivity were obtained when 820 g of glucose powder was directly added for making up 450 g/L of glucose at production stage.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.741-744
• /
• 2001

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.749-749
• /
• 1995

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2001.11a
• /
• pp.137-137
• /
• 2001

• Journal of Environmental Health Sciences
• /
• v.31 no.4 s.85
• /
• pp.322-326
• /
• 2005

연속반응조에서의 수소생산에 대한 수리학적체류시간(희석율, D)의 영향을 $1\%$ sucrose를 함유한 $37{\pm}1^{\circ}C$ 조건에서 조사하였다. 실험결과 수리학적체류시간(희석율)의 각각의 조건에 따라 생성된 가스중 수소성분은 $50~71\%$의 범위로 발생되었다. $H_2/CO_2$ 비율은 희석율이 증가할 때 $H_2/CO_2$ 비율도 증가하였다. 최대수소생성 수율은 희석율 0.14 l/h까지는 증가하다가 이후에는 감소하였고, 수소생성 수율은 0.81 l/g sucrose이었다. Acetate 생성 수율은 butyrate생성 수율 보다 희석율 조건변화에 민감하게 변화하였다. propionate 및 solvents는 희석율 변화에 영향을 받지 않았다 biomass 수율은 희석율이 0.2 l/h 까지는 증가하였으나, 그 이상의 조건에서는 감소하였다.

• Microbiology and Biotechnology Letters
• /
• v.18 no.1
• /
• pp.66-70
• /
• 1990

A study on 11 $\alpha$-hydroxylation of progesterone by using Rhizopus nigricans was carried out to produce efficiently 11 $\alpha$-hydroxyprogesterone which is an essential intermediate of corticosteroids synthesis. Firstly, medium was optimized in view of bioconversion yield and cell growth. Glucose and casamino acid were selected as carbon and nitrogen source and the ratio of carbon to nitrogen which maximize bioconversion yield was determined to be 2:1. Secondly, the addition time of progesterone and dispersion method were studied. When progesterone dispersed with 0.01% (v/v) Tween 80 was added at 12-14 hr of cultivation, higher bioconversion yield was obtained. When 20g/$\ell$ of progesterone was added, the yield reached 70% under optimized conditions.

• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.636-644
• /
• 2013

We examined the effects of soaking, saturation, and aging conditions of raw cowpea seeds, on the yield and growth responses of cowpea sprouts. The absorption caused rapid growth for the first two hours of soaking, then the growth slowed. The longer the soaking period (varied from 1 to 6 hours), the lower the germinability, yield ratio, and lateral root output became. A five-day saturation (moist $96{\pm}1%$, $20^{\circ}C$) treatment led to higher germinability, yield ratio, and lateral root output than no treatment and one- or three-day saturation treatment. High-temperature aging treatment led to lower germinability and yield ratio compared to no such treatment. Taking these findings into account, the optimal treatment conditions of raw cowpea seeds are a five-day saturation (moist $96{\pm}1%$, $20^{\circ}C$) treatment followed by cleaning and growing.