서지주요정보
이단계 에탄올발효공정의 모델링 및 전산모사 = Modelling and simulation of two-stage ethanol fermentation process
서명 / 저자 이단계 에탄올발효공정의 모델링 및 전산모사 = Modelling and simulation of two-stage ethanol fermentation process / 이용석.
저자명 이용석 ; Lee, Yong-Seok
발행사항 [대전 : 한국과학기술원, 1996].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8006608

소장위치/청구기호

학술문화관(문화관) 보존서고

DCHE 96007

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Continuous cultures with cell retention by an internal membrane filter were carried out using tapioca hydrolysate as medium to produce ethanol. Tapioca hydrolysate is one of cheap industrial media used widely in domestic alcohol production factories. In this study, the resulting mixture after liquefaction and saccharification of tapioca, contained 210~240 g/L of reducing sugars, of which about 92% was glucose and about 8% was maltose. In a total cell retention culture operated at a dilution rate of 0.18 /$h^{-1}$, the yeast concentration, the residual reducing sugar concentration, the ethanol concentration, and the volumetric ethanol productivity were about 40 g/L, 15 g/L, 81.4 g/L, and 14.7 g/L-h, respectively. In another cell retention culture operated at a dilution rate and a bleed rate of 0.20 /$h^{-1}$ and 0.14, respectively, the yeast concentration increased to 22 g/L and the ethanol concentration oscillated around 68 g/L. The volumetric ethanol productivity was about 13.6 g/L-h and the residual reducing sugar concentration about 12 g/L containing glucose of about 4.5 g/L. It was observed that maltose could not be consumed at all due to the repression by the residual glucose in all of the continuous cultures carried out using tapioca hydrolysate. Batch cultures were carried out for several initial concentrations of glucose and maltose to observe more carefully the repression by glucose of maltose utilization, a kind of catabolite repression, and to obtain necessary data sets for modelling. A model for ethanol production from a glucose-maltose mixture has been proposed, with a term representing the glucose repression effect on maltose consumption. The kinetics of glucose repression was represented most appropriately by a saturation type function with a single parameter called repression constant in this study. The model parameters were estimated from batch experimental data mentioned above. The maximum growth rates were determined by a smooth cubic spline approximation. The maximum growth rate on glucose (0.401 /$h^{-1}$) was found to be considerably higher than that on maltose (0.353 /$h^{-1}$), while the ethanol yield from maltose (0.451) was slightly higher than that from glucose (0.429). The cell yield from glucose (0.109) was almost same to that from maltose (0.104). Monod constants for glucose and maltose, and the repression constant were determined based on goodness-of-fitting. Results of sensitivity analysis on these three parameters showed that a change of 10% in these parameters had no significant effect on data fitting. It was thought that the dilution rate should be kept very low to maintain the glucose concentration very low when tapioca hydrolysate was used, which contained both glucose and maltose. Otherwise, it was expected that maltose could not be consumed due to the repression by glucose, making the substrate utilization very low. However, a very low dilution rate meant a low volumetric productivity of the process. To overcome such a difficulty, three types of two-stage processes were considered. Guide lines to determine optimal operation condition were suggested for them. The first one was consisted of a continuous stirred tank bioreactor, a buffer tank, and a secondary fed-batch fermentor. The second one was consisted of a continuous stirred tank bioreactor and a secondary fed-batch fermentor. The third one was consisted of a continuous stirred tank bioreactor and a plug flow bioreactor. From simulation results on these three systems using the model previously established, we could see that the substrate utilization was improved by having the secondary fermentor, while the overall volumetric productivity of the whole fermentor system decreased significantly. The second process showed the best performance in overall. But, a more careful economic study on fermentor installation cost and operation cost must be followed for a detailed and accurate optimization of the two-stage processes. Finally, a software for on-line cell concentration monitoring, one of important tools for monitoring and realization of optimal operations of fermentation processes under consideration, was developed. A laser turbidimeter was used. A third-order correlation between the sensor signal, that is, optical density, and the cell mass concentration was constructed. The parameters of this correlation equation were found strongly depended upon agitation speed. A rather simple algorithm was proposed to remove measurement noise and to compensate for the effect of agitation speed. A user-friendly software package out of this algorithm was developed, which had capabilities of data acquisition, noise filtering, estimation, data storage, graphic display, and interaction with the user.

서지기타정보

서지기타정보
청구기호 {DCHE 96007
형태사항 xv, 141 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 : Ⅰ, 주발효조와 Fed-batch형태의 후발효조 및 buffer tank를 연결한 이단계 공정의 전산모사 프로그램의 source list. - Ⅱ, 주발효조와 Fed-batch형태의 후발효조만을 연결한 이단계 공정의 전산모사 프로그램의 source list. - Ⅲ, 주발효조와 plug-flow형태의 후발효조를 연결한 이단계공정 전산모사 프로그램의 source list. - Ⅳ, OASIS(I) (On-line Analysis System for Instrument Signal (I)) 프로그램의 source list
저자명의 영문표기 : Yong-Seok Lee
지도교수의 한글표기 : 장용근
지도교수의 영문표기 : Yong-Keun Chang
수록 잡지명 : "Modelling of ethanol production by saccharomyces cerevisiae from a glucose and maltose mixture". Biotechnology Letters. Chapman and Hall, England, vol 17, no. 10, pp. 791-796 (1995)
학위논문 학위논문(박사) - 한국과학기술원 : 화학공학과,
서지주기 참고문헌 : p. 118-122
주제 모델링
타피오카
이단계발효공정
에탄올발효
Modelling
Tapioca
Two-stage Process
Ethanol Fermentation
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