scholarly journals Mass Transfer in Multiphasic Gas/Liquid/Liquid Systems. KLa Determination Using the Effectiveness-Number of Transfer Unit Method

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 156 ◽  
Author(s):  
Éric Dumont
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Gas Flow ◽  
Absorption Capacity ◽  
Operating Conditions ◽  
Transfer Unit ◽  
Liquid Systems ◽  
Overall Mass Transfer Coefficient

The Effectiveness-Number of Transfer Unit method (ε-NTU method) was applied to determine the overall mass transfer coefficient, KLa, of operating gas-liquid absorbers treating Volatile Organic Compounds (VOCs). This method requires the knowledge of the operating conditions (gas flow rate, QG; liquid flow rate, QL; scrubber volume V), the measurement of gaseous concentrations at the inlet, CGin, and at the outlet, CGout, of the contactor (in order to determine the effectiveness of the absorber ε) and the calculation of the Henry coefficient of the VOC between the gas and the liquid phases (HVOC). Coupled with the “equivalent absorption capacity” concept, the ε-NTU method was used to determine KLa of absorbers contacting a gas and a mixture of water and a Non Aqueous Phase, successfully. The method, validated from literature data for configurations countercurrent scrubbers and stirred tank reactors, could be used to simply determine the overall mass transfer coefficient of systems for which the standard KLa determination methods still remain non-reliable or inaccurate (viscous solvents, mixture of immiscible liquids, fermentation broths…).

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 .

scholarly journals Investigation of overall mass transfer coefficient of CO2 absorption in packed Column

2020 ◽  
Vol 13 (2) ◽  
pp. 153-157
Author(s):  
Zahraa N. Abd ◽  
Salih A. Rushdi
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Continuous Process ◽  
Packed Bed Reactor ◽  
Absorption Time ◽  
Overall Mass Transfer Coefficient

Mixtures of different types of amine solution Monoethanolamine, Diethanolamine, and Triethanolamine were experimentally used to investigate the overall mass transfer coefficient (KGa) at different operating parameters. The experiments were made in a packed bed reactor (PBR) with 75 cm in high and10 cm inside diameter as a gas-liquid contactor at 25℃ and atmospheric pressure, using a simulation gaseous mixture (air, carbon dioxide)  with recycle stream (semi-continuous process). Experimental design process Taguchi was employed. Four factors and three levels were chosen and exploded using L9 (3 ^4) orthogonal array design. These parameters for semi-continuous  process were namely: gas flow rate 5,10,and 15 L/min ,airflow rate80,90,and 100 L/h, liquid flow rate 400,450,and 500 mL/min  and time absorption time  30,45,and 60min . A Shimadzu GC-8A Gas Chromatograph with a thermal conductivity detector was used to measure the CO2 concentration absorbed in aqueous blended solution. The maximum value for CO2 loading was 8.622 (mol CO2/mol amine) at 15 L/min gas flow and 450 mL/min liquid flow and 100 L/h airflow for 60 min from absorption time. The results showed that the max value of KGa is 0.048 S-1.

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.

Dispersed air flotation as a pretreatment process for seawater desalination

2012 ◽  
Vol 12 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Hossam Altaher ◽  
Emad ElQada ◽  
Waid Omar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Seawater Temperature ◽  
Operating Conditions ◽  
Oxygen Absorption ◽  
Aeration Tank ◽  
Overall Mass Transfer Coefficient ◽  
Air Flotation

Pretreatment of seawater before reverse osmosis (RO) processes with dispersed air flotation involves a change in oxygen concentration in seawater. In order to understand this phenomenon, a series of experimental aeration studies was conducted. Aeration tests were performed under different operating conditions of seawater temperature, flow rate of the air and depth of the water in the aeration tank. The experimental results show that the overall mass transfer coefficient increases by increasing air flow rate. A measured increase in the overall mass transfer coefficient was observed with elevation of the temperature from 24 to 38 °C. The estimated value of activation energy of oxygen absorption in seawater is 42.5 kJ/mol. The value of the overall mass transfer coefficient is found to be affected by diffuser type and stirrer speed as these parameters influence the bubble size and the surface area available for mass transfer of oxygen from air bubbles to seawater.

Mass Transfer Enhancement for CO2 Absorption in Structured Packed Absorption Column

2019 ◽  
Vol 41 (5) ◽  
pp. 820-820
Author(s):  
Pongayi Ponnusamy Selvi and Rajoo Baskar Pongayi Ponnusamy Selvi and Rajoo Baskar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Flow ◽  
Aqueous Ammonia ◽  
Volume Flow Rate ◽  
Packed Column ◽  
Operating Conditions ◽  
Co2 Absorption ◽  
Absorption Column

The acidic gas, Carbon dioxide (CO2) absorption in aqueous ammonia solvent was carried as an example for industrial gaseous treatment. The packed column was provided with a novel structured BX-DX packing material. The overall mass transfer coefficient was calculated from the absorption efficiency of the various runs. Due to the high solubility of CO2, mass transfer was shown to be mainly controlled by gas side transfer rates. The effects of different operating parameters on KGav including CO2 partial pressure, total gas flow rates, volume flow rate of aqueous ammonia solution, aqueous ammonia concentration, and reaction temperature were investigated. For a particular system and operating conditions structured packing provides higher mass transfer coefficient than that of commercial random packing.

Influence of Gas-Liquid Distribution Inducer on Mass Transfer Coefficient in Rotating Packed Bed

2014 ◽  
Vol 908 ◽  
pp. 277-281
Author(s):  
Fei Wu ◽  
Jie Wu ◽  
Mei Jin ◽  
Fang Wang ◽  
Ping Lu
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Rotor Blade ◽  
Gas Flow ◽  
Packed Bed ◽  
Contact Length ◽  
Liquid Distribution ◽  
Rotating Packed Bed

Based on acetone-H2O system, the influence of the gas-liquid distribution inducer on the mass transfer coefficient in the rotating packed bed with the stainless steel packing was investigated. Furthermore, the absorption performance was also obtained under the experimental condition of the rotational speed of 630 rpm, the gas flow rate of 2 m3/h and the liquid flow rate of 100 L/h in the rotating packed bed with different types and different installation ways of the distribution inducer. The experimental results showed that the volumetric mass transfer coefficient Kyα per unit contact length of gas-liquid was increased by 8.6% for the forward-curved fixed blade, by 19.8% for the backward-curved rotor blade and by 33.2% with the combination of the straight radial rotor blade and the backward-curved fixed blade, respectively. Furthermore, when the gas flow rate was 2.5 m3/h, Kyα per unit contact length of gas-liquid was increased by 2.9% for the forward-curved fixed blade, by 25.3% for the backward-curved rotor blade, by 42.7% for the combination of the straight radial rotor blade and the backward-curved fixed blade, respectively. The results indicated that the distribution inducer play an important role on the improvement of the mass transfer coefficient in acetone-H2O system.

scholarly journals TOTAL VOLUMETRIC MASS TRANSFER COEFFICIENT AT CO2 GAS ABSORPTION USING K2CO3 BY MSG PROMOTER

Konversi ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Erlinda Ningsih ◽  
Abas Sato ◽  
Mochammad Alfan Nafiuddin ◽  
Wisnu Setyo Putranto
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Total Mass ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Gas Flow Rate ◽  
Co2 Gas

Abstract- One of the most widely used processes for CO2 gas removal is Absorption. Carbon dioxide is the result of the fuel combustion process which of the hazardous gases. The aim of this research is to determine the total mass transfer coefficient and analyze the effect of the absorbent flow rate of the absorbent solution with the promoter and the gas flow rate to the total mass transfer coefficient value. The variables consisted of liquid flow rate: 1, 2, 3, 4, 5 liter/min, gas flow rate: 15, 25, 30, 40, 50 liter/min and MSG concentration: 0%, 1%, 3% and 5% by weight. The solution of Pottasium Carbonate as absorbent with MSG promoter is flowed through top column and CO2 gas flowed from bottom packed column. Liquids were analyzed by titration and the gas output was analyzed by GC. From this research, it is found that the flow rate of gas and the liquid flow rate is directly proportional to the value of KGa. The liquid flow rate variable 5 liters / minute, gas flow rate 15 l / min obtained value of KGa 11,1102 at concentration of MSG 5%. Keywords:  Absorption, CO2,  K2CO3, MSG. 

scholarly journals NO Separation Characteristics in Integrated Electromigration Membrane Reactor

2020 ◽  
Vol 10 (15) ◽  
pp. 5071
Author(s):  
Zuwu Wang ◽  
Guifen Shen
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Total Mass ◽  
Membrane Reactor ◽  
Gas Flow ◽  
Separation Efficiency ◽  
Discharge Voltage ◽  
Gas Flow Rate

An integrated electromigration membrane absorption method has been proposed for the separation of NO from simulated mixed gas. The experiments were conducted to investigate the effect of discharge voltage, gas flow rate, inlet concentrations, and absorbents on the NO separation efficiency and total mass transfer coefficient in the integrated electromigration membrane reactor. The experimental results demonstrated that the NO separation efficiency and total mass transfer coefficient increased with the increase in the applied discharge voltage of the integrated electromigration membrane reactor. Regardless of discharge or not, the separation efficiency of NO continuously decreased with the increase in the gas flow rate and inlet concentration of NO in the experimental process. The total mass transfer coefficient of NO increased first and then decreased with an increase in the gas flow rate, while it decreased with an increase in NO inlet concentration. Compared with the membrane absorption without discharge voltage under the condition tested, at a discharge voltage of 18kV, the NO separation efficiency and the total mass transfer coefficient increased by 48.7% and 9.7 times, respectively.

Experimental Investigation on Ozone Mass Transfer Coefficient Enhanced by Electric Field in Liquid Phase

2013 ◽  
Vol 864-867 ◽  
pp. 2139-2144 ◽  
Author(s):  
Yang Lin Li
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Ozone Concentration ◽  
Total Mass ◽  
Gas Flow ◽  
Electrode Spacing ◽  
Gas Flow Rate

In order to improve the efficiency of ozone mass transfer in liquid phase, the method enhanced by electric field was put forward. The effect on ozone mass transfer was investigated from voltage, electrode spacing and gas flow rate. The result showed that ozone concentration in water and the total mass transfer coefficient increased correspondingly with the increase of the voltage, and ozone concentration in water and the total mass transfer coefficient increased correspondingly with increase of the electrode spacing in the range from 1 to 3 cm, and ozone concentration in water increased correspondingly with increase of the gas flow rate, but the total mass transfer coefficient reduced correspondingly.

Influence of Physical Properties of Phases on Hydrodynamics and Mass Transfer Characteristics of a Liquid-Liquid Circular Microchannel

2016 ◽  
Author(s):  
Mehdi Sattari-Najafabadi ◽  
Bengt Sundén ◽  
Zan Wu ◽  
Mohsen Nasr Esfahany
Keyword(s):  
Mass Transfer ◽  
Physical Properties ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Rate Ratio ◽  
Operating Conditions ◽  
Flow Rate Ratio ◽  
Internal Diameter ◽  
Volumetric Mass Transfer Coefficient

The influences of operating conditions and physical properties of the two phases on the hydrodynamics and mass transfer in a circular liquid-liquid microchannel have been investigated. The polytetrafluoroethylene (PTFE) microchannel has an internal diameter of 0.7 mm and a T-shaped mixing junction. Sodium hydroxide solution was used as the aqueous phase. N-hexane and toluene were employed as the organic phases to investigate the effect of physical properties. Regarding the results, at constant total flow rate, raising the flow rate ratio enhanced the overall volumetric mass transfer coefficient. Using toluene as the organic solvent enhanced the overall volumetric mass transfer coefficient in average by 64.7% and 100.27% comparing to n-hexane-water at flow rate ratio of 1 and 0.5, respectively. This increment resulted in a decrement in the required mass transfer time and length in the microchannel. The length of the slugs had no considerable variation as n-hexane was replaced with toluene. Thus, the significant improvement of the overall volumetric mass transfer coefficient was because of the increment of the overall mass transfer coefficient, not the specific interfacial area.

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