scholarly journals Hydrodynamics of a three-phase external-loop airlift bioreactor

2000 ◽  
Vol 55 (21) ◽  
pp. 4961-4972 ◽  
Author(s):  
Carla Freitas ◽  
Maria Fialová ◽  
Jindrich Zahradnik ◽  
José A. Teixeira
Author(s):  
J. Lamterkati ◽  
L. Ouboubker ◽  
M. Khafallah ◽  
A. El afia

<p><span>The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.</span></p>


Author(s):  
Abhishek Dutta ◽  
Sergio Valdivia-Rivera ◽  
Manuel Alejandro Lizardi-Jiménez

Abstract The aim of this study was to simultaneously evaluate diesel transfer rate (DTR) and oxygen transfer rate (OTR) on the production of an oil-degrading consortium in a three-phase airlift bioreactor (ALB) working at high hydrocarbon phase concentration with the purpose of determine whether the oxygen transfer rate is increased or diminished by an increase in the oil-phase concentration. Increase in hydrocarbon concentration allows an increase in DTR and a consequently higher DTR/OTR ratio thus avoiding hydrocarbon mass transfer limitations. This study demonstrates evidence that at high diesel concentrations, the main carbon fate is the production of biosurfactants.


1996 ◽  
Vol 16 (2-3) ◽  
pp. 145-153 ◽  
Author(s):  
M. Gavrilescu ◽  
R.-V. Roman

Sign in / Sign up

Export Citation Format

Share Document