A recursive node imbalance method incorporating a model of flowrate dynamics for on-line material balance of complex flowsheets

Makni, S.; Hodouin, D.; Bazin, C.

doi:10.1016/0892-6875(95)00037-q

Cited by 22 publications

(10 citation statements)

References 4 publications

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“…Thus, the oxygen mass transfer coefficient (K L a) is a useful tool in evaluating the effect of oxygen on fermentation process (Elibol and Ozer 2000;Sahoo and Agarwal 2002). In submerged fermentation, the oxygen mass transfer coefficient serves to compare the efficiency of bioreactors and their mixing devices and is one of the most important scaleup factors (Makni et al 1995). The data of K L a under various aeration rates and agitation speeds are given in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Influence of agitation and aeration on growth and antibiotic production by Xenorhabdus nematophila

Wang

Zhang

2006

World J Microbiol Biotechnol

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The effect of agitation and aeration on the growth and antibiotic production by Xenorhabdus nematophila YL001 grown in batch cultures were investigated. Efficiency of aeration and agitation was evaluated through the oxygen mass transfer coefficient (K L a). With increase in K L a, the biomass and antibiotic activity increased. Activity units of antibiotic and dry cell weight were increased to 232 U ml -1 and 19.58 g l -1 , respectively, productivity in cell and antibiotic was up more than 30% when K L a increased from 115.9 h -1 to 185.7 h -1 . During the exponential growth phase, DO concentration was zero, the oxygen supply was not sufficient. So, based on process analysis, a three-stage oxygen supply control strategy was used to improved the DO concentration above 30% by controlling the agitation speed and aeration rate. The dry cell weight and activity units of antibiotic were further increased to 24.22 g l -1 and 249 U ml -1 , and were improved by 24.0% and 7.0%, compared with fermentation at a constant agitation speed and a constant aeration rate (300 rev min -1 , 2.5 l min -1 ).

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Section: Resultsmentioning

confidence: 99%

Influence of agitation and aeration on growth and antibiotic production by Xenorhabdus nematophila

Wang

Zhang

2006

World J Microbiol Biotechnol

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“…Standard stationary observer (ST) proposed by Makni et al (1995). Autocovariance based stationary observer (ABS) presented by Vasebi et al (2012a).…”

Section: Observer Performance Evaluationmentioning

confidence: 99%

“…It generally relies on static mass and energy conservation constraints that could be extracted from plant flow diagrams. For slow dynamic regimes, stationary observers (Makni et al, 1995;Vasebi et al, 2012a), generalized dynamic observers (Darouach and Zasadzinski, 1991;Rollins and Devanathan, 1993;Xu and Rong, 2010) and integral linear dynamic observers (Bagajewicz and Jiang, 1997;Tona et al, 2005) are valuable options. In addition to mass conservation constraints, these observers require inventory variations to be either modeled or measured.…”

Section: Introductionmentioning

confidence: 99%

Determining a dynamic model for flotation circuits using plant data to implement a Kalman filter for data reconciliation

Vasebi

Poulin

Hodouin

2015

Minerals Engineering

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“…To achieve this dual objective, general criteria for data reconciliation can be de®ned to take simultaneously into account all measured variables and all conservation models, each one being affected by a weight that corresponds to the level of con®dence that one has in each measurement and each conservation model. This dual objective has been used successfully for mineral processing plants [14,18].…”

Section: Data Reconciliation Techniquementioning

confidence: 99%

KL a Evaluation during the course of fermentation using data reconciliation techniques

Pouliot

Thibault

Garnier

et al. 2000

Bioprocess Engineering

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The oxygen mass transfer coef®cient often serves to compare the ef®ciency of bioreactors and their mixing devices as well as being an important scale-up factor. In submerged fermentation, four methods are available to estimate the overall oxygen mass transfer coef®cient (K L a): the dynamic method, the stationary method based on a previous determination of the oxygen uptake rate (Q O 2 X), the gaseous oxygen balance and the carbon dioxide balance. Each method provides a distinct estimation of the value of K L a. Data reconciliation was used to obtain a more probable value of K L a during the production of Saccharomyces cerevisiae, performed in 22.5-l fed-batch bioreactor. The estimate of K L a is obtained by minimising an objective function that includes measurement terms and oxygen conservation models, each being weighted according to their level of con®dence. Weighting factors of measurement terms were taken as their respective inverse variance whereas weighting factors of oxygen conservation models were obtained using Monte Carlo simulations. Results show that more coherent and precise estimations of K L a are obtained.List of symbols C L dissolved oxygen concentration, mol/m 3 C 0 L pseudo-steady-state dissolved oxygen concentration recorded at the initiation of the dynamic method, mol/m 3 C Ã L dissolved oxygen concentration in equilibrium with mean gaseous oxygen concentration, mol/m 3 C P dissolved oxygen concentration recorded by the probe, mol/m 3 K L a overall oxygen mass transfer coef®cient, s À1 J objective function P pressure, Pa Q G gas¯ow rate, m 3 /s Q O 2 X oxygen uptake rate, mol/m 3 s R gas constant, 8.306 Pa m 3 /(mol K) S substrate, mol/m 3 RQ respiratory quotient T temperature, K V L liquid volume in the fermenter, m 3 y gaseous mole fractionGreek letters a weighting factor associated to each term in the objective function b relative weighting factor between measurements and conservation models s P time constant of the dissolved oxygen probe, s

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A recursive node imbalance method incorporating a model of flowrate dynamics for on-line material balance of complex flowsheets

Cited by 22 publications

References 4 publications

Influence of agitation and aeration on growth and antibiotic production by Xenorhabdus nematophila

Influence of agitation and aeration on growth and antibiotic production by Xenorhabdus nematophila

Determining a dynamic model for flotation circuits using plant data to implement a Kalman filter for data reconciliation

KL a Evaluation during the course of fermentation using data reconciliation techniques

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