Hydrodynamic Study of Bubbles in a Bubble Column Reactor Part II – Numerical Study

2015 ◽  
Vol 813-814 ◽  
pp. 1023-1027
Author(s):  
S. Arunkumar ◽  
V. Harshavardhan Reddy ◽  
T.M. Sreevathsav ◽  
M. Venkatesan
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Bubble Column ◽  
Numerical Study ◽  
Image Processing Technique ◽  
Bubble Velocity ◽  
Bubble Column Reactor ◽  
Hydrodynamic Characteristics ◽  
Flow Rates ◽  
Column Reactor

The present work deals with the use of CFD analysis and the validation of the experimental work carried out on the artificial splitting of an air bubble in a bubble column reactor. In Part I of this work, artificial splitting of bubble in a bubble column rector is experimentally studied by using a high speed camera. Image processing technique was used to identify bubble size and bubble velocity. In present work CFD simulations are carried out using ANSYS FLUENT software using Volume of Fluids (VOF) method. VOF is based on a surface tracking technique applied to a fixed Eulerian space. The phase fraction in physical quantities that can be used to distinguish the distribution of gas hold up in a bubble Column reactor. The numerical study of splitting of bubble into two bubbles of nearly equal size is considered. In the bubble column reactor, the liquid phase is stationary and gas flow rate in it is varied. The superficial gas flow rates are 10 lph, 15 lph, 20 lph and 25 lph. The characteristics of bubble after splitting which include its shape, size and velocity for various gas flow rates mentioned above are studied numerically and are compared with experimental results. These hydrodynamic characteristics play a pivotal role in the reactions occurring between the liquid and gas phases in the bubble column reactor.

Hydrodynamic Study of Bubbles in a Bubble Column Reactor Part I – Image Processing

2015 ◽  
Vol 813-814 ◽  
pp. 1018-1022
Author(s):  
S. Naveen ◽  
T. Sriram ◽  
S. Prithvi Raj ◽  
M. Venkatesan
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Bubble Column ◽  
Waste Water Treatment ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Bubble Column Reactor ◽  
Hydrodynamic Characteristics ◽  
High Speed Photography ◽  
Stationary Liquid Phase

The study of bubble column reactors has its significance in applications such as multiphase reactors, aerators and in industrial waste-water treatment. Extensive works has been done in studying the hydrodynamics of a single gas bubble flowing through stationary liquid phase. The natural breakup of bubble during its motion has been studied in the past. In the Part I of the present work, hydrodynamics of an air bubble after its artificial splitting using a stainless steel mesh is experimentally studied using image processing and high speed photography. The significance of bubble splitting is that it increases the surface area of contact between stationery and moving fluid which in turn increases the rate of reaction desired during the process. The motion of the bubble is captured during its release and after splitting using High-Speed Camera. The velocity, area and diameter of the bubble before and after splitting are calculated by applying Image processing technique on the high speed photograph. The splitting of the bubble is found to vary with the superficial gaseous velocity. The splitting of bubbles into two bubbles of nearly equal size is considered and its hydrodynamic characteristics are studied.

scholarly journals CARBON DIOXIDE BIOFIXATION BY Chlorella sp. IN A BUBBLE COLUMN REACTOR AT DIFFERENT FLOW RATES AND CO2 CONCENTRATIONS

2019 ◽  
Vol 36 (2) ◽  
pp. 639-645 ◽  
Author(s):  
Reza Pourjamshidian ◽  
Hossein Abolghasemi ◽  
Mohammad Esmaili ◽  
Hossein D. Amrei ◽  
Mehran Parsa ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Bubble Column ◽  
Bubble Column Reactor ◽  
Flow Rates ◽  
Column Reactor ◽  
Chlorella Sp ◽  
Co2 Concentrations

scholarly journals An Experimental Investigation of Overall Mass Transfer coefficient ( K_Ga ) of 〖CO〗_2 absorption using Monoethanolamine(MEA) and Diethanolamine(DEA) in a Bubble Column Reactor (BCR)

2020 ◽  
Vol 13 (1) ◽  
pp. 67-73
Author(s):  
Elaf Thamera ◽  
Salih Abduljabbar Rushdi
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Column Reactor ◽  
Air Flow Rate ◽  
Column Reactor ◽  
Overall Mass Transfer Coefficient

In this work, an absorption technology   was used actually to investigation the  mass transfer coefficient of carbon dioxide from a gaseous mixture (air, carbon dioxide) in  blended solution Monoethanolamine (MEA) and Diethanolamine (DEA)  in a bubble column reactor (BCR) . The bubble column reactor(BCR) was made of Plexiglas with 1.5 m high and 0.1 m inside diameter. The overall mass transfer coefficient (  was evaluated at different operating conditions , gas flow rate, air Flow rate ,liquid flow rate .Where the gas flow rates were 10, 15 and 20 L /min ,  air flow rate 100,150 and 200 L/h ,and liquid flow rate 5 ,10,15 L /min . This experiment  by   using  continuous   process with helping centrifugal  pump  . High-performance gas chromatographic (GC) was performed to evaluate  loading during absorption experiment . The  experimental results have shown that the   loading in range of  0.581-1.367 (mol  /mole amine),and the maximum value of overall mass transfer coefficient ( KG) was 0.04 S-1 .

Ozonation of domestic secondary effluent for recycling and reuse - a pilot plant study

2002 ◽  
Vol 46 (4-5) ◽  
pp. 361-366 ◽  
Author(s):  
C.H. Ni ◽  
J.N. Chen ◽  
Y.C. Tsai ◽  
W.B. Chen ◽  
C.H. Chen
Keyword(s):  
Pilot Plant ◽  
Gas Flow ◽  
Bubble Column ◽  
Removal Rate ◽  
Ozone Treatment ◽  
Bubble Column Reactor ◽  
Secondary Effluent ◽  
Sand Filtration ◽  
Recycled Water ◽  
Column Reactor

In this study, a pilot plant combined ozonation with sand filtration is established. Wastewater from the secondary effluent was taken as the sample for looking into the feasibility of domestic wastewater recovery and recycling. At the beginning, a series of hydraulic analysis and ozone transfer tests was conducted in the bubble column reactor. From these tests, it was found that when the gas flow is controlled to within 0.2∼1.0 L/min and liquid flow within 0.5∼2.5L/min, using series connected mixing tank model for our calculation, the result J (CSTR) is 1∼2. From the ozone transfer test it is known that the smaller the gas flow, the better the transfer rate, and the same pattern occurs on ozone gas concentration. After sand filtration and ozone treatment, the G/L ratio within the ozone column reactor can be maintained within 0.2∼0.4 and the ozone dosage within 8∼12 mg/L. The removal rate for coliform bacillus, BOD, turbidity and color is 99.96%, 62.2%, 89.6% and 67% respectively. After ozonation treatment, coliform bacillus content can be controlled under 10 CFU/mL, BOD under 10mg/L, turbidity within 2.0∼2.5 (NTU), and color within 10.3∼13.7 degree. The recycled water is almost colorless and odorless, and is capable of reaching the reference standard for recycled water.

Mathematical model involving chemical reaction and mass transfer for the ozonation of dimethyl phthalate in water in a bubble column reactor

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
Jianbing Wang ◽  
Zhilin Xia ◽  
Zuhai Cao ◽  
Shaoxia Yang ◽  
Wanpeng Zhu
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Gas Phase ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Column Reactor ◽  
Dimethyl Phthalate ◽  
Ozone Absorption ◽  
Column Reactor ◽  
Tracer Experiments

AbstractThis research investigated the establishment of a mathematical model for the ozonation of dimethyl phthalate (DMP) through the analysis of the mass transfer and reactions in a semi-batch bubble column reactor. Negative step tracer experiments were conducted with ozone as a tracer, which indicated that the gas phase is perfectly well mixed at the gas flow rate of 400 mL/min. Based on the results from ozone absorption experiments the mass transfer coefficient of ozone was determined to be 0.0054 s

Chemical Reaction Effect upon Gas–Liquid Interfacial Area in a Bubble Column Reactor

2013 ◽  
Vol 11 (1) ◽  
pp. 587-593 ◽  
Author(s):  
Antonio Blanco ◽  
Alicia García-Abuín ◽  
Diego Gómez-Díaz ◽  
Jose M. Navaza
Keyword(s):  
Gas Flow ◽  
Bubble Column ◽  
Interfacial Area ◽  
Bubble Column Reactor ◽  
Fast Reaction ◽  
Experimental Conditions ◽  
Column Reactor ◽  
Hydrodynamic Parameters ◽  
State Regime ◽  
Account Due

Abstract This work analyses the influence of different experimental conditions over important hydrodynamic parameters of a bubble column reactor, such as bubble size distribution, gas hold-up and the gas–liquid interfacial area. The influence of gas flow-rate (18–40 L h–1) and reagent concentration (0–0.5 mol L–1) in the liquid phase upon these hydrodynamic parameters have been studied. The influence of experiment time must also be taken into account due to non-steady-state regime. Under these considerations, the chemical absorption rate changes throughout time, and it produces important changes upon the global absorption process, due to modifications in the gas–liquid interfacial area. The presence of a fast reaction in the liquid bulk has the highest influence upon interfacial area.

scholarly journals Effect of pH and Gas Flow Rate on Ozone Mass Transfer of Κ-Carrageenan Solution in Bubble Column Reactor

REAKTOR ◽  
2019 ◽  
Vol 18 (04) ◽  
pp. 177 ◽  
Author(s):  
Aji Prasetyaningrum ◽  
Dyah Arum Kusumaningtyas ◽  
Purbo Suseno ◽  
Ratnawati Ratnawati
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Gas Flow ◽  
Bubble Column ◽  
Operating Conditions ◽  
Bubble Column Reactor ◽  
Gas Flow Rate ◽  
Column Reactor

This research was conducted to calculate the mass transfer coefficient value for ozonation reaction of κ-carrageenan solution in the bubble column reactor. Ozone gas was produced using ozone generator type corona discharge. In this study, operating conditions were regulated at ozone gas flow rate 2- 5 L min-1, pH 4-10, and temperature 29 ± 1 oC. Samples were tested every 5 minutes to determine the dissolved ozone concentration. The results showed that dissolved ozone concentrations increased with increasing ozonation time and ozone gas flow rate. However, a very high gas flow rate can increase turbulence so that the mass transfer coefficient (kLa) value decreased. In alkaline conditions, the formation of free radicals (HO*) increases so that the amount of dissolved ozone decreases. The kLa value of ozone gas in κ-carrageenan solution is slightly lower than the kLa value of the ozone gas in the water. The results of this study indicate that (kLa) ozone gas in water is 0.131 / minute while the value (kLa) in κ-carrageenan solution is 0.128 / minute.

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