Liquid-Solid Mass Transfer Behavior of a New Stirred-Tank Reactor with a Packed Bed Fixed to its Wall

2013 ◽  
Vol 36 (4) ◽  
pp. 603-610 ◽  
Author(s):  
M. H. Mowena ◽  
A. A. Zaatout ◽  
G. H. Sedahmed
2014 ◽  
Vol 37 (9) ◽  
pp. 1525-1531 ◽  
Author(s):  
Mohamed A. El-Naggar ◽  
Mohamed H. Abdel-Aziz ◽  
Ahmed A. Zatout ◽  
Gomaa H. Sedahmed

Author(s):  
Lei Wang ◽  
Xiao Xu ◽  
Hualin Wang ◽  
HongLai Liu ◽  
Qiang Yang

A gas-liquid stirred tank reactor (STR) has some problems, such as low mass transfer efficiency, high exhaust gas oxygen concentration, and low product conversion rate, due to limitations of stirring speed and input power. This article proposes a method to enhance the gas-liquid mass transfer in a STR using circulating jet internals. When a circulating jet is added, the average bubble size in the reactor is reduced to 1.26 mm, and the overall gas holdup is increased to 8.23%, which is an increase of 3.62 times of the original STR. The gas-liquid volumetric mass transfer coefficient is increased to 0.05556 s-1, which is 4.84 times of the original STR. The unit volume power is increased by only 1.4 times. These data provide references for the design and scale-up of new jet STRs.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kashyap Kumar Dubey ◽  
Dhirendra Kumar ◽  
Punit Kumar ◽  
Shafiul Haque ◽  
Arshad Jawed

Bioconversion of colchicine into its pharmacologically active derivative 3-demethylated colchicine (3-DMC) mediated by P450BM3 enzyme is an economic and promising strategy for the production of this inexpensive and potent anticancer drug. Continuous stirred tank reactor (CSTR) and packed-bed reactor (PBR) of 3 L and 2 L total volumes were compared for the production of 3-demethylated colchicine (3-DMC) a colchicine derivative using Bacillus megaterium MTCC*420 under aerobic conditions. Statistical optimization technique was utilized with the most significant variables, that is, dissolved oxygen (DO), colchicine concentration, and process time for optimization. The validation of the model was performed by experiments on the predicted values in an individual run, and the optimum parameters were DO (~50%), colchicine concentration (7.5 g/L), and process time (39 h) resulted in a maximum bioconversion of 3-DMC 3.36 g/L. The PBR reactor achieved much higher productivity (6.58 g/L/h) as reported by earlier researchers. This is the first report on the use of PBR for bioconversion of colchicine.


2021 ◽  
Vol 165 ◽  
pp. 426-434
Author(s):  
Samah Mustafa ◽  
Mahmoud M. Taha ◽  
Ahmed A. Zatout ◽  
Gomaa H. Sedahmed ◽  
Dina A. El-Gayar

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