Capture of Carbon Dioxide Using Aqueous Ammonia in a Lab-Scale Stirred-Tank Scrubber

2014 ◽  
Vol 955-959 ◽  
pp. 1927-1934 ◽  
Author(s):  
Pao Chi Chen ◽  
L.C. Lin
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Absorption Rate ◽  
Aqueous Ammonia ◽  
Ph Value ◽  
Stirred Tank ◽  
Process Variables

A pH-stat stirred-tank scrubber for capturing carbon dioxide using aqueous ammonia was used to explore the effects of process variables on the absorption of carbon dioxide. In order to maintain the pH value of the solution, aqueous ammonia was automatically introduced into the tank through the action of a pH-controller. The process variables were the pH of the solution, gas-flow rate, gas concentration and stirring speed. The absorption rate and mass-transfer coefficient could be determined by means of mass balance at a steady-state. It was found that the liquid-flow rate was 0.50-58.33 ml/min; the removal efficiency was in the range of 30.1-100% and the loading of CO2 was in the range of 0.02425-0.5661 mol-CO2/mol-NH3. The results also showed that the absorption rate was in the range of 5.14x10-5 to 6.27x10-4 mol/s-L, while the mass-transfer coefficient was in the range of 0.015 to 0.14 1/s. The effects of mixing on the absorption rate, mass-transfer coefficient and loading of CO2 were also discussed in this work.

scholarly journals Carbon Dioxide Absorption in a Fabricated Wetted-Wall Column Using Varying Concentrations of Aqueous Ammonia

2014 ◽  
Vol 13 (2) ◽  
pp. 9
Author(s):  
H.E.E. Ching ◽  
L.M.P. Co ◽  
S.I.C. Tan ◽  
S.A. Roces ◽  
N.P. Dugos ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Flue Gas ◽  
Carbon Capture ◽  
Aqueous Ammonia ◽  
Co2 Absorption ◽  
Wetted Wall Column

Due to the continued increasing levels of CO2 emissions that is contributing to climate change, CO2 mitigation technologies, particularly carbon capture and storage, are being developed to address the goal of abating CO2 levels. Carbon capture technologies can be applied at the pre-combustion, oxy-fuel combustion, and post-combustion stages, the latter being the most widely used due to its flexibility. Among the several CO2 separation processes available for carbon capture, absorption is the most widely used where amine solutions are used as absorbents. This paper highlights the use of a wetted wall column fabricated by Siy and Villanueva (2012) and simulated flue gas to determine the performance of CO2 absorption in terms of the percentage of CO2 absorbed, the steady state time, and the overall gas mass transfer coefficient. The concentrations used were 1, 5, 10, and 15% NH3(aq) at a constant temperature range of 12-17ºC, solvent flow rate of 100 mL/min, and simulated flue gas flow rate of 2 L/min. It was found that increasing the solvent concentration resulted in a proportional increase both in the percentage of CO2 absorbed and the overall gas mass transfer coefficient. The average percentage of CO2 absorbed ranged within 52.25% to 95.29% while the overall mass transfer coefficient ranged from 0.1843 to 0.7746 mmol/m2∙s∙kPa. However, erratic behavior was seen for the time required for the system to reach steady state. Using Design ExpertTM for analysis, the results showed that the effect of varying the concentration had a significant effect on the percentage of CO2 absorbed and the overall gas mass transfer coefficient. The results proved that the greater the aqueous ammonia concentration, the greater the percentage of CO2 absorbed. The range of 5-10% aqueous ammonia is recommended because the percentage of CO2 absorbed peaks at an average of 92% beyond the range of 5-10%.

Preliminary Study on Biomitigation Green House Gas Carbon Dioxide in Closed System Bubble Photobioreactor: Relationship Among the Mass Transfer Rate and CO2 Removal Efficiency in High Level of CO2

2014 ◽  
Vol 69 (6) ◽  
Author(s):  
Astri Rinanti ◽  
Kania Dewi ◽  
Dea Indriani Astuti ◽  
Nico Halomoan
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Mass Transfer Rate ◽  
Co2 Concentration ◽  
Co2 Removal ◽  
Co2 Removal Efficiency

Emission of carbon dioxide (CO2) is a major contributor to global warming. Biofixation of CO2 by microalgae in photobioreactors seems to be a promising strategy for CO2 mitigation. The research to determine the overall mass transfer coefficient (kLa) has been done to find the way on biomitigation CO2 emission by using biologically Carbon Capture and Sequestration method. This research was conducted according to green microalgae Scenedesmus obliquus activity, which is cultivated in a bubble photobioreactor through the mass transfer process that assumed adequate mixing occurs. Flow rate of CO2 that supplied to the system were 2 L/min, 5 L/min and 8 L/min, when each rate flowed into the photobioreactor with high CO2 concentration (v/v) of 2%, 5% and 10%. The highest CO2 removal efficiency occurred at culture that supplied with an CO2-enriched air flow rate of 5 L/min. The kLa (CO2) value is the highest in 0.3582/day at 2% CO2 concentration and flow rate of 2 L/min, while the lowest is in 0.0503/day at 5% CO2 concentration and flow rate of 8 L/min. In terms of solubility is inversely proportional to the flow rate, the less carbon dioxide is dissolved at the rate of 8 L/min as well as the value of the kLa. The results showed that the variation of flow rate will affect the amount of mass transfer coefficient, growth rate and cell biomass.  Higher flow rate decreases kLa value as well as CO2 removal efficiency.

Absorption of oxygen into solutions of polymers

1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal
Keyword(s):  
Mass Transfer ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Flow Curve ◽  
Liquid Flow Rate ◽  
Polymer Concentration ◽  
Newtonian Liquids

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.

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 Dynamics simulation of ammonia nitrogen absorption in a rural–urban canal on the Northeast China Plain

2018 ◽  
Vol 78 (3) ◽  
pp. 622-633 ◽  
Author(s):  
Yujia Song ◽  
Xiaodong Wang ◽  
Haiying Zhang
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Absorption Rate ◽  
Ammonia Nitrogen ◽  
Dynamics Simulation ◽  
Background Concentration ◽  
Absorption Length ◽  
Average Value ◽  
Variation Range

Abstract To study dynamic laws of ammonia nitrogen retention in a typical rural–urban fringe canal, NaBr was selected as a conservative tracer agent, and NH4Cl as an additive nutritive salt to conduct an instantaneously added tracer experiment outdoors. On this basis, tracer additions for spiralling curve characterisation (TASCC) method and nutritive spiral indexes were used for the quantitative depiction of retention dynamics of NH4+-N. The Michaelis–Menten (M-M) model was used to simulate absorption dynamic characteristics of NH4+-N. Results showed that the variation range of absorption length of NH4+-N under background concentration was 93.94–295.54 m with an average value of 177.41 m, the variation range of mass transfer coefficient was 0.16–0.38 mm/s with an average value of 0.26 mm/s, and the variation range of absorption rate was 0.16–0.38 mg/(m2⋅s) with an average value of 0.26 mg/(m2⋅s). The maximum absorption rate of NH4+-N obtained via M-M equation simulation was 0.59–1.38 mg/(m2⋅s), and the subsaturation constant was 1.10–5.03 mg/L. The variability of the dynamic absorption length, overall dynamic absorption rate, and overall dynamic mass transfer coefficient shown by NH4+-N within the range from background concentration to saturation concentration certified that TASCC could analyse the dynamic process of NH4+-N retention and absorption by the canal.

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.

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