• 한국환경과학회지
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• 제13권3호
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• pp.319-325
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• 2004

An experimental study on the preparation of monolithic porous polymers by environmentally friend process in supercritical carbon dioxide has been carried out. Polymerization mixture composed of a cross-linking monomer, initiator and functional co-polymer was charged in the reactor with sapphire window. After the system was purged with a flow of $CO_2$ for 15 min, the reactor was pressurized with liquid $CO_2$ up to 100 bars. The reactor was isolated from and placed back to the system via quick connector for shaking until the mixture had become fully homogeneous. The reactor was then heated and pressurized to the required reaction conditions and left overnight. After cooling and $CO_2$ evacuation, the polymer was removed from the reactor as dry, white, continuous monoliths. The effect of experimental conditions on the physical properties of porous polymer was systematically examined, and it was found that monomer content had a major effect on the physical properties of the polymers.

• 한국환경보건학회지
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• 제22권1호
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• pp.57-64
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• 1996

The main objectives of this research program were to study the ozonation characteristics of phenol wastewater in the continuous packed colamn reactor(PCR) and the bubble column reactor (BCR) using ozone and to provide the fundamentals of ozonizing the phenol wastewater. Among various influencing factors that affect on phenol decomposition through the oxidation by ozone, contacting method, and ozone flow rate were chosen as reaction parameters. The results were obtained from two different types of contacting methods where the countercurrent flow was more efficient than the cocurrent flow in both the phenol removal efficiency and the ozone utilization efficiency. Furthermore, PCR showed the phenol removal efficiency 1.6 to 3% higher than that of BCR in both contacting methods, as well as the ozone utilization efficiency, suggesting that the countercurrent flow is more efficient than the cocurrent flow. The phenol removal efficiency and the ozone utilization efficiency were reduced in both reactors as the influent ozone flow rate increased. Upon varing flow rate from 0.5l/min to 2.0 l/min by 0.5 l/min, the phenol removal efficiency was reduced approximately from 8.5% to 10.5% and the ozone utilization efficiency was reduced approximately from 6% to 8% in both reactors. The performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• 환경위생공학
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• 제13권1호
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• pp.147-156
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• 1998

A synthesis process for PZT powder using $NH_{3}$ gas as a precipitator in a bubble column reactor was experimentally successful in develope a production process of piezoelectric ceramic PZT powder. Also as a reaction by coprecipitation, the crystalized PZT ceramic powder at the condition of over pH 9 could be attained. The time needed for reaction on the condition of $NH_{3}$ gas flow rate = 0.5 1/min, Ar gas flow rate = 2.0 1/min. Feed flow rate = 2.33 ml/sec was less than five minutes, so it could synthesize PZT powder for such a few moments. And the synthesized PZT powder was $0.17{\mu}m$ in diameter on an average.

• 한국식품과학회지
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• 제30권1호
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• pp.110-117
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• 1998

고정화 transglucosidase (TG)를 이용한 충진형 반응기를 만들어 isomaltooligosaccharides (IMO)의 연속생산 가능성을 살펴보고 기질용액의 농도와 유속에 따른 반응산물의 생성패턴과 운전안정성을 조사하였다. 고정화 TG에 의한 IMO의 생성패턴은 soluble TG의 경우와 동일하였다. 충진형반응기에 의해 생성된 포도당과 isomaltose의 농도는 기질인 maltose 용액의 농도와 종류에 관계없이 유속의 증가에 따라 지속적으로 감소되는 경향을 보였고 isomaltotriose 역시 10% 기질용액을 사용한 경우를 제외하고 같은 경향을 보였다. 반면, panose의 농도는 유속의 증가에 따라 증가하다가 감소하는 경향을 보였다. 기질농도가 10% 일 때, IMO의 최대수율은 2 mL/min 유속에서 52.1%였고, 20%와 30% (w/v)일 때는, $0.5{\sim}1.0\;mL/min$ 유속에서 각각 $39.0{\sim}38.0%,\;12.1{\sim}14.2%$의 최대수율을 보였다. 20%의 maltose를 함유한 조제당화액을 사용했을 때의 수율은 유속이 0.5 mL/min일 때 36.3%였다 본 충진형반응기는 $55^{\circ}C$에서 안정되게 운전되었다. 144시간 운전후에 초기 활성의 85%, 288시간 경과후에도 약 65%의 활성이 잔존하였다. 본 실험결과로 보아 IMO를 생산하기 위해 고정화 TG를 이용한 충진형반응기를 적용하는 것은 가능성이 클 것으로 예상되었다.

• KSBB Journal
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• 제16권4호
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• pp.398-402
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• 2001

본 연구에서는 고정화된 한천분해효소가 충진된 packed-bed reactor를 이용하여 한천올리고당을 연속생산하였다. Packed-Bed 형 Reactor의 H/D를 조절하여 생산율이 가장 좋은 조건을 살펴 본 결과, H/D=14인 것으로 나타났으며, 한천올리고당의 연속생산시 35 h에서 효소활성반감기를 나타내었다. Packed-Bed Reactor내에서 기질 1 g/L agar, 1unit 고정화효소, 4$0^{\circ}C$, flow rate 24 mL/min 조건하에서 연속반응 시켰을 때, 중합도 4의 한천올리고당이 주로 생산되었으며 중합도 6당, 2당순으로 생산됨을 알 수 있었다. 또한 다중으로 연결된 반응기를 이용한 결과, 기질 1 g/L agar, 4$0^{\circ}C$, 48 mL/min의 조건하에서 41.7 mg/h의 한천올리고당이 생산됨으로서 다중으로 연결하지 않은 반응기보다 2.3배 한천올리고당의 생산율이 증가하였음을 알 수 있었다.

• Environmental Engineering Research
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• 제9권1호
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• pp.13-22
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• 2004

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.647-651
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• 1987

Yeast biomass in a biological continuous stirred tank reactor was controlled with an APPLE II microcomputer using adaptive control theory of bilinear systems. The controller used is as simple as a PID controller, but required less information. Cell concentration was well controlled by adjusting the inlet flow rate following the algorithm.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권3호
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• pp.163-170
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• 2002

This report describes the use of a transtubular bioreactor to study the relative effects of diffusion versus perfusion of medium on antibody production by a hybridoma cell line. The study was performed with a high-density cell culture maintained in a serum-free, low-protein medium for 77 days. It was determined that the reactor possessed a macro-mixing pattern residence time distribution similar to a continuous stirred tank reactor (CSTR), However, due to the arrangement of the medium lines in the reactor, the flow patterns for nutrient distribution consist of largely independent medium path lengths ranging from short to long. When operated with cyclic, reversing, transtubular medium flow, some regions of the reactor (with short residence times) are more accessible to medium than others (with long residence times). From this standpoint, the reactor can be divided into three regions: a captive volume, which consists of medium primarily delivered via diffusion; a lapped volume, which provides nutrients through unilateral convection; and a swept volume, which operates through bilateral convection. The relative sizes of these three volumes were modified experimentally by changing the period over which the direction of medium flow was reversed from 15 min (larger captive volume) to 9 h (larger swept volume). The results suggest that antibody concentration increases as the size of the diffusion-limited (captive) volume is increased to a maximum at around 30 min with a sharp decrease thereafter. As reflected by changes in measured consumption of glucose and production of lactate, no significant difference in cellular metabolism occurred as the reactor was moved between these different states. These results indicate that the mode of operation of the transtubular bioreactor may influence antibody productivity under serum-free, low-protein conditions with minimal effects on cellular metabolism.

• 한국대기환경학회지
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• 제18권3호
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• pp.223-230
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• 2002

Titania photocatalytic oxidation reactors were studied to investigate degradation efficiencies of hydrocarbons. In general, it is well known phenomena that thin layered titania oxidizes most of hydrocarbons to carbon dioxide and water under UV light. In this study, degradation efficiencies were measured due to changes in reactor structures, UV sources, the number of titania coatings, and various hydrocarbon chemicals. It was proven that gas degradation efficiencies are related to such factors as UV transmittance of coating substance, collision area of surface, and gas flow rate. For packing type annular reactor, about 98% degradation efficiency was achieved for achieved for propylene of 500 ppm level at a flow rate of 100 ml/min. Several gases were also tested for double-coated titania thin film under the condition of continuous flow of 100 ml/min and 365 nm UV source. It was shown that degradation efficiencies were decreasing in the order: $C_3$ $H_{6}$, n-C$_4$ $H_{10}$, $C_2$ $H_4$, $C_2$ $H_2$, $C_{6}$ $H_{6}$ and $C_2$ $H_{6}$./. 6/./.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.501-506
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• 1998

A mathematical model is developed to describe the relationship between the manipulated variables (e.g. jacket inlet temperature and feed flow rate) and the important qualities (e.g conversion and weight average molecular weight (Mw)) in a continuous polymerization reactor. The subspace-based identification method for Wiener model is used to retrieve from the discrete sample data the accurate information about both the structure and initial parameter estimates for iterative parameter optimization methods. The comparison of the output of the identified Wiener model with the outputs of a non-linear plant model shows a fairly satisfactory degree of accordance.