• Title/Summary/Keyword: Stirred tank

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Development of Soluble Glucan Production Process with Continuous Stirred Tank Fermentor (연속 발효조를 이용한 soluble glucan 생산 공정 개발)

  • Moon, Chan-Jun;Lee, Jung-Heon
    • Journal of Life Science
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    • v.16 no.6
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    • pp.938-941
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    • 2006
  • Continuous fermentation process for the production of soluble glucan using mutant Agrobacterium sp. ATCC31750 has been developed in this research. When the concentration of soluble glucan was higher than 6 g/l, the viscosity of the fermented broth was too high and it needs complex separation process to separate from culture broth. Mathematical models which describe the cell growth and glucan production was developed and they kinetic parameters were estimated with experimental data. They are used for the optimization of continuous fermentation process and calculate optimal dilution rate for easy separation of glucan 4 g/l. With continuous fermentation, glucan production rate was increased 1.8 times more than that with batch fermentation.

A Study on the Design of Denitrification Reactor and the Characteristics (탈질화 반응기의 설계 및 특성에 관한 연구)

  • 김선화;송주영
    • Journal of Life Science
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    • v.11 no.3
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    • pp.273-278
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    • 2001
  • Removal of nitrogen compound from waste water is essential and often accomplished by biological process. Deni-trification bacterium. Paracoccus denitrificans(KCTC 2350) is employed to estimate the ability and the characteristics of denitrification. In the immobilized biological reactor system, the measurement of absolute amount of active strain in the reactor is comparatively difficult or impossible. In this study, strain immobilized denitrification reactor was designed with the unwoven texture wrapped peeped hole plastic tube to calculated the absolute amount of active strain by comparing the activity of the immobilized reactor adn the free cell reactor. The reactor system was continuous stirred tank reactor and the rate of substrate consumption was assumed to be Michaelis-Menten equation. As a result, we found that the amount of immobilized active strain was the half of the total active strain in the reactor and the time required to reach in the equilibrium state in the immobilized reactor system was shorter than that of the free cell reactor system.

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Robust Predictive Feedback Control for Constrained Systems

  • Giovanini, Leonardo;Grimble, Michael
    • International Journal of Control, Automation, and Systems
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    • v.2 no.4
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    • pp.407-422
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    • 2004
  • A new method for the design of predictive controllers for SISO systems is presented. The proposed technique allows uncertainties and constraints to be concluded in the design of the control law. The goal is to design, at each sample instant, a predictive feedback control law that minimizes a performance measure and guarantees of constraints are satisfied for a set of models that describes the system to be controlled. The predictive controller consists of a finite horizon parametric-optimization problem with an additional constraint over the manipulated variable behavior. This is an end-constraint based approach that ensures the exponential stability of the closed-loop system. The inclusion of this additional constraint, in the on-line optimization algorithm, enables robust stability properties to be demonstrated for the closed-loop system. This is the case even though constraints and disturbances are present. Finally, simulation results are presented using a nonlinear continuous stirred tank reactor model.

Development of Bioreactors for Hydrogen-Producing Immobilized Photosynthetic Bacteria(I) : Evaluation of lmmobilized CSTR for Hydrogen Productivity and Effectiveness Factor (광합성 박테리아를 이용한 고성능 수소 생산 고정화 생물반응기의 개발(I) 고정화 연속 교반탱크 반응기에서의 수소 생산성 및 효율인자 평가)

  • 선용호;한정우
    • KSBB Journal
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    • v.8 no.3
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    • pp.243-255
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    • 1993
  • In this study, it was observed that hydrogen Productivity varied with stirrer speed, bead radius, input glucose concentration and dilution rate in a continuous stirred tank reactor in which immobilized R. rubrum KS-301 was used as a hydrogen-producing bacterium The mass transfer resistance due to cell immobilization was also studied. In order to estimate an effectiveness factor, Des of glucose was first obtained, which was subsequently represented by the correlation equation between Dos and Xb, As a result external mass transfer resistance could be neglected for stirrer speeds greater than 400rpn With bead radius increasing, the hydrogen productivity and internal effectiveness factor decreased. With input 91ucose concentration increasing, the hydrogen productivity and interval and external effectiveness factor increased. Although an Internal effectiveness factor was not affected, hydrogen productivity Increased with dilution rate increasing. An overall effectiveness factor remained nearly constant for the dilution rates investigate4 but increased with input 91ucose concentration increasing.

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Increased Poly(3-Hydroxybutyrate) Accumulation in Recombinant Escherichia coli from Whey by Agitation Speed Control

  • Kim, Beom-Soo;Brian K. O'Neill;Lee, Sang-Yup
    • Journal of Microbiology and Biotechnology
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    • v.10 no.5
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    • pp.628-631
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    • 2000
  • The timing of poly(3-Hydroxybutyrate) (PHB) biosynthesis was controlled by varying the agitation speed of a stirred tank fermentor during the pH-stat fed-batch culture of recombinant Escherichia coli strain GCSC 6576 harboring pSYL107. Using a concentrated whey solution containing ca. 200 g/l lactose as the nutrient feed, the PHB content was only 57% after 35h due to volumetric limitation of the fermentor. However, by limiting the oxygen by maintaining the agitation speed at 300 rpm, the final PHB content increased to 70% after 70h with a cell concentration of 15 g/l. When the agitation speed was increased up to 500 rpm, a cell concentration of 31 g/l with 80% PHB was obtained after 52h. A further increase in the maximum agitation speed increased the cell concentration, PHB concentration, and PHB productivity, however, the PHB content decreased to 56-58%.

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균체재순환 반응기에서의 젖산 생산

  • 유익근;장호남
    • Microbiology and Biotechnology Letters
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    • v.22 no.3
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    • pp.277-282
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    • 1994
  • In batch cultures of Lactobacillus delbrueckii, cell growth and lactic acid production were affected by two main factors, inhibition by lactic acid and limitation by nutritional components. In order to increase th productivity significantly, a continuous stirred tank reactor with cell recycle was employed. A cell desnity of 145g dry weight/l and a volumetric productivity of 73 g/l$\cdot $h were obtained with an effluent concentration of 85 g/l lactic acid. The productivity achieved by this system was 23-fold higher than those obtained by the corresponding batch cultivations. Once the lactic acid concentration reached the steady steady state, lowering the yeast extract concentration caused the reduction of the lactic acid concentration without affection the biomass concentration. Finally, the formation of D-lactate was investgated. During the various cultures, a small amount of D-lactate always formed, even thought a majority of lactate was L-isomer, It was supposed that the relative amount of the D-lactate was affected by glucose limitation, and there seems to exist a certain relationship between the concentration of D-lactate and acetate.

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Cultivation of Digitalis lanata Cell Suspension in an Aqueous Two-Phase System

  • Choi, Yeon-Sook;Lee, Sang-Yoon;Kim, Dong-Il
    • Journal of Microbiology and Biotechnology
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    • v.9 no.5
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    • pp.589-592
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    • 1999
  • Suspension cultures of Digitalis lanata were successfully performed in an aqueous two-phase system (ATPS) of 4.5% polyethylene glycol (PEG) 20,000 and 2.8% crude dextran. Cell growth in the medium containing an individual ATPS-forming polymer was inhibited due to the toxicity of PEG and a high viscosity of dextran. Formation of ATPS supported cell growth by showing a considerably decrease in viscosity and partitioning of cells into a PEG-lean dextran phase. It was found that an aqueous two-phase cultivation of plant cells in a stirred tank bioreactor could be successfully applied.

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Nitrogen removal performance of anammox process with PVA-SA gel bead crosslinked with sodium sulfate as a biomass carrier

  • Tuyen, N.V.;Ryu, J.H.;Yae, J.B.;Kim, H.G.;Hong, S.W.;Ahn, D.H.
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.326-332
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    • 2018
  • In this study,the result shows that polyvinyl alcohol-sodium alginate (PVA-SA) gel bead crosslinked with sodium sulfate are better among the different methods by comparing the relative mechanical strength, mechanical strength swelling and expansion coefficient of beads in water. Subsequently, anammox biomass entrapment by PVA-SA gel was introduced into continuous stirred tank reactor (CSTR). After 24 operation days, the nitrogen removal efficiency achieved 60%, while the nitrogen loading rate (NLR) was $0.14kgN/m^3/d$ and the experiment data indicated that PVA-SA gel bead crosslinked with sodium sulfate can be used to initiate anammox process. Furthermore, it is an alternative for culturing anammox in a long-term operation.

GA-Based Design of a Nonlinear PID Controller and Application to a CSTR Process (GA 기반의 비선형 PID 제어기 설계 및 CSTR 프로세스에 응용)

  • Lee, Joo-Yeon;So, Gun-Baek;Lee, Yun-Hyung;So, Myung-Ok;Jin, Gang-Gyoo
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.6
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    • pp.633-641
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    • 2015
  • Several complex processes that are employed in industries, such as shipping, power plants, and the petrochemical industry, involve time-varying behavior as well as strong nonlinear behavior during operation. The fixed-parameter proportional-integral-derivative (PID) controllers have difficulty in dealing with control problems that occur in such processes. In this paper, we propose a method of designing a nonlinear PID controller for industrial processes that exhibit a large number of nonlinearities and time-varying behavior. The gains of the nonlinear PID controller are characterized by a simple nonlinear function of the error and/or error rate depending on the process set-point and output. We tune the user-defined parameters using a genetic algorithm by minimizing the integral of time absolute error (ITAE) index. We verify the effectiveness of the proposed method by performing a comparison of the proposed method and two other nonlinear and adaptive methods that are employed for reference tracking, disturbance-rejection performances, and robustness to parameter changes on a continuously stirred tank reactor.

Development of Practical Advanced Oxidation Treatment System for Decontamination of Soil and Groundwater Contaminated with Chlorinated Solvents (TCE, PCE): Phase II (염소계 화합물(TCE, PCE)로 오염된 토양 및 지하수 처리를 위한 실용적 고도산화처리시스템 개발 (II))

  • Kim, Sang-Yeek;Sohn, Seok-Gyu;Kong, Sung-Ho
    • Journal of Soil and Groundwater Environment
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    • v.15 no.2
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    • pp.10-17
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    • 2010
  • Advanced oxidation processes (AOPs) have advantages to reduce the processing time and mineralize contaminants dissolved in groundwater. Recently, remediation techniques for organic contamination in groundwater have been studied, and technology using $UV/H_2O_2$ is generally accepted as one of the most powerful and reliable alternative for the remediation of groundwater contamination. In this study, $UV/H_2O_2$ technology, which generates hydroxyl radical ($\cdot$ OH) as known for strong non-selective oxidant, was used to degrade chlorinated solvents (TCE and PCE), and it was expanded to apply continuous stirred tank reactor (CSTR) system (i.e. combinations of three CSTR). The tested parameters for CSTR system were retention time and groundwater/$H_2O_2$ injection volume ratio. To find optimum parameters for CSTR system, various retention time (6 min ~ 90 min) and groundwater/$H_2O_2$ injection volume ratio (5/1 ~ 119/1) were tested. Other conditions for CSTR were adapted from the batch test results, which concentration of $H_2O_2$ and UV dose were 29.4 mM (0.1%) and 4.3 kWh/L, respectively. Based on the experimental results, the optimum parameters for CSTR system were 20 min for retention time and 119/1 for groundwater/$H_2O_2$ injection volume ratio. Applying these optimum conditions, chlorinated solvents (TCE and PCE) were removed at 99.9% and 99.6%. Moreover, the effluent concentrations of TCE and PCE are 0.036 mg/L and 0.087 mg/L, respectively, which are satisfied the regulatory level (TCE 0.3 mg/L, PCE 0.1 mg/L). Consequently, the CSTR system using $UV/H_2O_2$ technology can achieve high removal efficiency in the event of treatment of groundwater contaminated by chlorinated solvents (TCE and PCE).