서지주요정보
(A) study on internal-filtration system for continuous high cell density culture = 고농도 연속 배양을 위한 내부 여과 시스템에 관한 연구
서명 / 저자 (A) study on internal-filtration system for continuous high cell density culture = 고농도 연속 배양을 위한 내부 여과 시스템에 관한 연구 / Byung-Geon Park.
저자명 Park, Byung-Geon ; 박병건
발행사항 [대전 : 한국과학기술원, 1998].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8008384

소장위치/청구기호

학술문화관(문화관) 보존서고

DCHE 98004

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Among the options for high productivity in fermentation processes, bioreactor system development, as well as development of strains with high activity and optimization of operating conditions, are very important. In order to obtain high cell densities it is essential to retain cells inside the reactor as long as possible. For this purpose, cell recycle with internal membrane was adopted. All the ceramic filters used in this study for the internal filter system were tubular type and made by a sintering process. The average pore size of symmetric and asymmetric ceramic membrane was 0.3 and 0.005㎛ respectively. The pore size of stainless steel used in this study was 2㎛. For the optimum design of the internal membrane module, a relationship between the radius of the membrane tube and the ratio of the membrane surface per effective fermentation volume was worked out. It was found that there is an optimum dimensionless radius (r/R) in order to achieve the maximum ratio of the membrane surface area : fermentation volume. Factors affecting the permeation flux during the filtration of fermentation medium and broth by using a symmetric and an asymmetric ceramic membrane were investigated in an internal filter bioreactor. After sterilization of the fermentation medium the flux of the asymmetric membrane was 1.8 folds higher than that before sterilization. At 100g/l glucose, flux index (Fi) at steady state was only 21.8% for the asymmetric membrane and 42.2% for the symmetric membrane. When cell free broth was filtered, Fi at the steady state was 48% for the symmetric membrane and 21% for the asymmetric membrane. For the asymmetric membrane, a decline in the flux by nearly 80% was observed when 100g/l glucose and 8.5g/l yeast extract coexisted in the medium. The dual function of the cake layer during the filtration of the fermentation broth was investigated in depth and a mathematical model was also developed in order to describe the dual function of the cake layer quantitatively. Periodic backflushing of tubular ceramic membrane filters with filtrate was employed to alleviate membrane fouling. There existed an optimum backflushing interval and time to give a maximum flux recovery. At 16g/L of yeast cell concentration, the mean flux increased about 4 times by employing repeated operation cycles consisting of 4.53 minutes of filtration, 4.5 seconds of intermission, and 40 seconds of backflushing. Effects of aeration, agitation speed, and yeast cell concentration were also investigated. The use of ultrasonic waves (20 kHz and 60~130 W) facilitated in situ regeneration of membranes after fouling by yeast cells or particles in the cake layer. A flux 20 ~80% higher than normal was achieved at 16g/l yeast cell suspensions. Optimum ultrasonic incidence conditions were 25sec/5min, 60W to achieve a maximum 84% of initial Fr after 10 minutes. No apparent influence on yeast cell growth, glucose consumption, and ethanol productions were observed at 60W ultrasonic incidence. However, at 110 W and longer time, incidence retarded glucose consumption and induced lower cell and ethanol concentrations during batch fermentation. When the stainless steel membrane had a negative charge, the permeation flux decreased very slowly compared with one with no charge. On the other hand, the adhesion of macromolecules to the membrane increased when the stainless steel membrane had a positive charge and the flux was even lower than the one without a charge in the end. Long-term continuous yeast culture with glucose was carried out successfully for more than 2 months employing the internal filtration system incorporated with backflushing unit as a model. A dilution rate of 0.2~$0.3hr^{-1}$ and a bleed ratio of 0.1~0.15 were used. Productivities of about 10 and 18g/l-hr were obtained at dilution rates of 0.2 and $0.3hr^{-1}$ respectively. In the continuous culture experiment using internal filtration system with wood hydrolysate and dilution rate $0.22hr^{-1}$, the maximum cell and ethanol concentrations were 1.5×$10^9$ cells/ml and 76g/l respectively and a productivity of 17g/l-hr was obtained.

서지기타정보

서지기타정보
청구기호 {DCHE 98004
형태사항 xvii, 146 p. : 삽도 ; 26 cm
언어 영어
일반주기 저자명의 한글표기 : 박병건
지도교수의 영문표기 : Ho-Nam Chang
지도교수의 한글표기 : 장호남
수록잡지명 : "Effects of periodic backflushing with filtrate on filtration performance in an internal-filtration bioreactor". Bioprocess Engineering. Springer, vol. 16, no. 5, pp. 253-256 (1997)
학위논문 학위논문(박사) - 한국과학기술원 : 화학공학과,
서지주기 Reference : p. 140-146
주제 Internal filtration module
Modeling of filter fouling behavior
Fouling reducing system
Long-term continuous high cell density culture
내부여과 모듈
필터여과성능 모델링
필터여과성능 개선 시스템개발
장기 연속고농도배양
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