Mass transfer studies in pneumatic reactors

Benyahia, Farid; Jones, Lynn; Petit, Silvain; Plantaz, David

doi:10.1002/ceat.270190507

Cited by 12 publications

(6 citation statements)

References 18 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The concentration of the dissolved oxygen in the liquid was measured continuously by means of two polarographic dissolved oxygen electrodes (Mettler Toledo T-type) connected to dissolved oxygen meters (Mettler Toledo O 2 4100) and recorded using a PC based data acquisition system. The volumetric mass transfer coefficient k L a was determined by the dynamic method described by Chisti [1] and Benyhaia et al [3]. In this work, values of the volumetric mass transfer coefficients (k L a) were obtained from the first order model [1]:…”

Section: Methodsmentioning

confidence: 99%

“…In aerobic bioreactors, the critical limiting factor in providing the optimal environment is the oxygen mass transfer, as a consequence of the low solubility of oxygen in fermentation media. Hence, the volumetric mass transfer coefficient (k L a), which is normally used to characterize the mass transfer performance, plays an important role in the performance of bioreactors [1][2][3]. Ideally, a reactor should have a maximum mass transfer rate, at an efficient mixing and at a minimum energy input [2].…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have demonstrated the airlift reactors ability to provide this [1,2,4]. However, the data presented in the literature for mass transfer in airlift reactors vary widely and is sometimes contradictory due, probably, to the wide range of reactors studied and differences in experimental techniques used [2,3]. Most experimental measurements [5,6] have shown that the rate of mass transfer in an airlift reactor is influenced by various design (i.e., bioreactor type and geometry), system (i.e., fluid properties) and operation (i.e., liquid and gas velocity and gas holdup) variables.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor

Freitas

Teixeira

2001

Chemical Engineering Journal

View full text Add to dashboard Cite

Determinations of volumetric mass transfer coefficient were conducted in a three-phase internal-loop airlift reactor with an enlarged degassing zone. The effect of parameters such as the airflow rate (riser superficial gas velocities between 0.01 and 0.5 m/s), solids loading (up to 30%, v/v), solids density (1023 and 1048 kg/m 3) and the liquid-phase properties on k L a was studied. It was observed that the increase of the airflow rate and the introduction of ethanol enhanced the volumetric mass transfer coefficient in the system. On the contrary, the progressive introduction of solids and a small increase on solids density were responsible for the diminishing of the mass transfer rate. Correlations for the volumetric mass transfer coefficient with the riser superficial gas velocity and solids loading were determined for the two solids density and the two liquid-phases. A good agreement between experimental data and the calculated values was obtained.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor

Freitas

Teixeira

2001

Chemical Engineering Journal

View full text Add to dashboard Cite

show abstract

“…The electrode response time was determined by the amount of time required to record the saturation DO concentration after a step change in concentration. The volumetric mass transfer coefficient K La was determined by the dynamic method described by Chisti [16] and Benyhaia, et al [17] …”

Section: Methodsmentioning

confidence: 99%

Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor

Lu¹,

Dagot²,

Baudu³

et al. 2010

J. Shanghai Univ.(Engl. Ed.)

View full text Add to dashboard Cite

International audienceIn this paper, the characteristics of fluid mixing time in a novel extra-loop fluidized bed were studied. The results showed that the mixing time was shortened with the increase of fluid velocity. All the discrete numbers of the reactor were above 0.2. The serial number n was 2.5-3.0. It was judged accordingly that the reactor fluid state was continous stirred tank reactor (CSTR) mainly. When the inspiratory capacity increased the mixing time of the reactor was shortened. Thus the air input was beneficial for the fluid mixing. During the three phases mixing process, the mixing time of the reactor could be decreased by the n increase of carrier and air loading together, but the change was not significant. The parameters affecting the reactor fluid state were fluid velocity, inspiratory capacity and carrier. K La could be increased with the air loading increase, and at the same gas/liquid ratio when the pressure drop was high, K La value was increased. The amount of carrier complex influence on K La. As the carrier loading continued to increase, its value had been dropped but the changes was not significant, and optimization condition was found at above 800-1 000 g carrier loading (pouzzolane) or 600 g PVC. Under gas/liquid ratio of 0.8%-5.2%, K La was (0.62-1.37)×10−2 s−1

show abstract

“…U aerobnim bioreaktorima, limitirajući faktor u podešavanju optimalnih uslova sredine mikroorganizmima je prenos mase kiseonika, zbog posledice slabog rastvaranja kiseonika u vodi, odnosno, u fermentacionim medijumima. Efikasnost prenosa mase kiseonika iz gasne u tečnu fazu, se najbolje opisuje preko vrednosti zapreminskog koeficijenta prenosa mase k L a [1][2][3].…”

Section: Univerzitet U Beogradu Tehnološko-metalurški Fakultet Karnunclassified

Influence of fluid-mechanical characteristics of the system on the volumetric mass transfer coefficient and gas dispersion in three-phase system

Knezevic¹,

Povrenovic²

2014

Hem Ind

View full text Add to dashboard Cite

Distribution of gas bubbles and volumetric mass transfer coefficient, k L a in a three phase system with different types of solid particles at different operation conditions were studied in this paper. The ranges of superficial gas and liquid velocities used in this study were 0.03-0.09 m/s and 0-0.1 m/s, respectively. The three different types of solid particles were used as a bed in the column (glass, d p of 3 and 6 mm and ceramic, d p of 6 mm). The experiments were carried out in 2D plexiglas column, 278 mm×20.4 mm×500 mm, and in cylindrical plexiglas column with the diameter of 64 mm and hight of 2000 mm. The k L a coefficient increases with gas and liquid velocities. The results show that the volumetric mass transfer coefficient has higher values in three phase system with solid particles in comparison to two phase system. The particles' properties (diameter and density) have major impact on oxygen mass transfer in three phase systems.

show abstract

Mass transfer studies in pneumatic reactors

Cited by 12 publications

References 18 publications

Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor

Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor

Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor

Influence of fluid-mechanical characteristics of the system on the volumetric mass transfer coefficient and gas dispersion in three-phase system

Contact Info

Product

Resources

About