Volumetric Mass Transfer Coefficient Research Articles

Improving the transfer of dissolved oxygen in a biological Fe2+ oxidation process using a venturi jet as an intensive aeration system

The low bio-production of Fe3+ as a leaching agent is one of the main limitations to implementing industrial bio-processes at feasibility conditions. The main limitation of the bio-oxidation process of Fe2+ is the low oxygen transfer to the aqueous phase because of the low oxygen solubility. This study assesses the effectiveness of the venturi jet as an innovative and intensive aeration device for overcoming the oxygen limitation in a continuous ferrous oxidation process in a fixed-bed reactor with immobilized acidithiobacillus ferrooxidans, in contrast to the conventional diffuser aeration device. Firstly, the influence of the airflow and the influence of the medium concentration were determined for the following parameters for both aeration devices; Volumetric mass transfer coefficient (kLa), Standard Oxygen Transfer Rate (SOTR), Standard Aeration Efficiency (SAE), and Standard Oxygen Transfer Efficiency (SOTE). Then, both aeration devices were compared in a continuous bio-oxidation process in an up-flow packed bio-reactor (UFPB). The system performance was assessed by monitoring temperature, pH, oxidation-reduction potential, and dissolved oxygen concentration for 69 days. Findings displayed that when aerating with the diffuser, the ferrous oxidation rate was restricted by the low dissolved oxygen availability, being about 1 ppm (1 mg L−1). Under these oxygen-limiting conditions, the maximum ferrous (Fe2+) oxidation rate was 9.09 g L−1 h−1. However, when aerating with the venturi jet, the dissolved oxygen concentration increased up to 2.70 mg L−1, achieving a maximum of 29.11 g L−1 h−1. So, this study has demonstrated that the change in the aeration device has resulted in an improvement in the process, achieving a 3.5-fold increase in the oxidation rate. Furthermore, the venturi jet offered additional advantages over the diffuser, such as requiring less power to deliver the same amount of air, being unaffected by jarosite precipitates, and not requiring a supply of compressed air.

Can ozone mass transfer in water treatment be enhanced through independent pressurized ozonation?

The dissolved ozone equilibrium concentration is hard to improve by increasing the gas phase partial pressure due to the low initial pressure and difficulty in pressurization. In this study, a novel hydraulic pressurization technology was developed to reliably elevate the ozonation pressure and improve the solubility of ozone. It was located downstream of the ozone generator to avoid generator overpressure. Specifically, at the optimal pressure of 0.30 MPa with an initial ozone flow rate of 1–6 L min−1, the specific surface area of bubbles and turbulent dissipation rate in the ozonation reactor were up to 2.5- and 1.5-fold that of the atmospheric aeration. Meanwhile, the dissolved ozone equilibrium concentration, redox potential, and volumetric mass transfer coefficient were up to 2.4-, 1.6-, and 2.7-fold that of atmospheric aeration, respectively. The increase in bubble-specific surface area and turbulent dissipation rate, synergistically enhanced the mass transfer, contributing 83.2–94.4 % and 5.6–16.8 %, respectively. As the reactor pressure was increased from 0 to 0.30 MPa, the decolorization time of Acid Red 18 was shortened from 20 to 8 min, and the COD removal rate increased from 48.0 % to 85.0 %. This work provides an alternative approach coupled with a novel device that enhances the ozone mass transfer during water treatment.

CFD–PBM coupled modeling of liquid–liquid interphase mass transfer behaviors inside the Kenics static mixer

Kenics static mixers (KSM) are commonly used in various industries for its excellent mass transfer performance. It is essential to systematically analyze the relationship between fluid parameters and mass transfer parameters to better understand the mass transfer behaviors between liquid–liquid phases and optimize the mass transfer efficiency of the KSM. In this work, a computational fluid dynamic–population balance model coupled method is utilized and three mass transfer models are compared and analyzed. Further simulations investigate the mass transfer behaviors inside the KSM under different superficial velocities, dispersed phase volume fractions, and aspect ratios. The results show that the increase of superficial velocity leads to the 2.23–14.15–fold increase of volumetric mass transfer coefficient and the 1.71–4.56–fold increase of mass transfer rate. What's more, increasing the dispersed phase volume fraction leads to the significant increase of 15.51 times in volumetric mass transfer coefficient and 34.92 times in mass transfer rate. Moreover, the increase of aspect ratio could result in the reduction of 4.19–1.72 times in volumetric mass transfer coefficient and 1.81–1.17 times in mass transfer rate. This work provides valuable theoretical insights for the optimal design of the KSM and the enhancement of mass transfer performance.

Microfluidic mass transfer of supercritical CO2 in brine

In the context of carbon sequestration in saline aquifers, we investigate CO2 transport dynamics in brine under reservoir-like conditions (P = 8 MPa, T = 50∘C) using microfluidics. We quantify the mass transfer of supercritical CO2 in brine across a range of concentrations (0–1 M) and liquid flow rates (15–60 μL/min) for the first time. We find the volumetric mass transfer coefficient kLa ranges from 50.3 to 144.0 s−1, increasing with flow rate and, to a lesser extent, with salinity. More importantly, the kLa value for supercritical CO2 in brine at a higher temperature shows a significant enhancement of >50% compared to gas and liquid CO2 in water. Our analysis, incorporating a theoretical mass transfer model, points to a dominant contribution from the liquid film to the overall kLa, nearly doubling that of the emulsion caps, attributed to the thin film's larger surface area and dynamic renewal.

Dynamic and interfacial properties for dichloromethane absorption in ionic liquids: Experimental and molecular dynamic insights

In this study, a strategy for dichloromethane (DCM) capture using ionic liquids (ILs) was systematically investigated from the perspective of dynamic analysis. The diffusion coefficient, Henry’s law constant (H), saturated absorption capacity, and overall volumetric liquid-side mass-transfer coefficient (KLao) of four types of ILs were obtained. Among all the ILs studied, tetrabutylphosphonium caproate ([P4444][C5COO]) demonstrated superior DCM absorption capabilities, and its corresponding H value (3.13 Pa m3/mol at 25 °C) was markedly lower than those of solvents documented in the literature. Furthermore, its KLao value was determined to be 2.77 × 10−3/s at 25 °C, which was measured in a customized cylindrical absorption bottle with a height of 150 mm and an inner diameter of 16 mm. The absorption bottle, fitted with a gas inlet tube having an inner diameter of 5 mm and positioned 5 mm above its base, utilized a simple bubbling technique to introduce gas into the liquid phase, eliminating the need for gas-dispersion equipment. Nevertheless, ILs with high affinities showed relatively high initial mass-transfer rates for DCM. Based on molecular dynamics (MD) simulations, the vapor–liquid interface properties, including mass and number density profiles, molecular orientation, and surface tension, were investigated. This revealed that in the pure [P4444][C5COO] system, the alkyl chain of the anion was oriented toward the gas phase, while the carboxyl group was oriented toward the bulk. The tilt angle of [C5COO]− with respect to the interface was within the range of 37° < θ′ < 70°. For the [P4444][C5COO]/DCM mixture, at the interface, the anion exhibits an enhanced ordered orientation, while the cation shows a more disordered orientation.

Experimental study of a leakage location method based on plug flow mass transfer characteristics

Leaks in water supply pipes pose a threat to water security. In order to save labor investment in pipeline leak location and to find a method to obtain the leak location by calculating upstream and downstream related data, an experimental study was conducted to investigate the plug flow mass transfer characteristics in horizontal pipelines. The results show that the addition of carbon dioxide gas can better detect the occurrence of small area ruptures in the pipeline. The translational velocity equation for elongated bubbles has better accuracy for both the insoluble gas air and the slightly soluble gas carbon dioxide. The local volumetric mass transfer coefficient shows a better linear relationship with the residual gas volume. The iterative equation derived from such a law can effectively predict the distribution of carbon dioxide concentrations in the pipeline. The study shows that the iterative equation, combined with the carbon dioxide concentration at a point downstream and the bubble translation velocity, can make a good localization judgment of the pipeline rupture point.

Population balance modeling-assisted prediction of oxygen mass transfer coefficients with optical measurements

Prediction of bubble size distributions (BSD) is challenging but necessary to develop a more advanced bubble population-based model for oxygen mass transfer with increased data quality while reducing the required experimental effort. In this paper, we experimentally investigated bubble sizes in a pilot-scale setup using a submersible in-situ flow-microscope. This technique enables bubble size measurements in dense bubbly flows and at airflow rates of up to 40 sL/min above the diffuser, where former measurement methods were limited to a range below 8 slpm with a comparable diffuser configuration. The data obtained were used to study coalescence and breakup behavior and to predict bubble size distributions using population balance modeling (PBM). We also investigated the prediction of the volumetric oxygen mass transfer coefficient based on measurement of bubble size at only one height in combination with PBM to provide reliable estimates of the apparent mass transfer rate with less experimental effort. A mass transfer rate estimate was obtained with deviations from the experimentally determined mass transfer rate of <10 %.

Analysis of Scale-Up and Characterization of the Volumetric Mass Transfer Coefficient for Gas Dispersion in Yield-Pseudoplastic Fluids Using a Coaxial Mixer

Analysis of Scale-Up and Characterization of the Volumetric Mass Transfer Coefficient for Gas Dispersion in Yield-Pseudoplastic Fluids Using a Coaxial Mixer

Stress modulation strategies in Kluyveromyces marxianus: Unravelling the effects of shear force and aeration for enhanced specific ergosterol production

AbstractErgosterol, as a precursor for synthesising useful molecules like vitamin D2, possesses significant physiological functions in both fungal and human systems. In fungi, ergosterol plays a crucial role in stress responses. In contrast to Saccharomyces cerevisiae yeast, the changes in specific ergosterol content of Kluyveromyces marxianus under various stress conditions are less known. This study investigated how ergosterol content changes in response to different stress factors. Carbon to nitrogen (C/N) ratio was examined using experimental design. The effects of aeration and shear force beside constant overall volumetric mass transfer coefficient (KLa) were examined. Cell growth and specific ergosterol content were investigated using ethanol stress during a two-stage fermentation. Based on the results, contradictory settings regarding C/N ratio and shear force were found to be favourable for cell growth and specific ergosterol content. However, increased aeration consistently elevated specific ergosterol content and favoured cell growth as well (2.5-fold and 1.5-fold, respectively). In K. marxianus fermentations, higher ergosterol yield can be achieved through a two-stage fermentation (138.9 mg L−1 compared to 52.9 mg L−1), where the first stage provides favourable conditions for cell growth, and the second stage involves stress (beneficial for ergosterol production) conditions. Conclusions drawn from the two-stage fermentation results suggest that early transitioning of cell growth to the second phase will not result higher adaption and specific ergosterol content compared to the transition at the end of exponential growth phase.

Xylitol biosynthesis and process scale-up from wheat straw hemicellulosic hydrolysate using Candida tropicalis

Due to growing applications of xylitol in pharma and food industries, process development for xylitol biosynthesis from lignocellulosic biomass seems to be a promising strategy. The present study focuses on the process development for facilitating efficient xylose to xylitol bioconversion from wheat straw hemicellulosic hydrolysate using Candida tropicalis ATCC 13803. A methodical attempt to scale up the fermentation bioprocess is demonstrated by maintaining a constant volumetric mass transfer coefficient (kLa) in bioreactors of various scales. Xylitol productivity of 1.47 and 0.58 g/Lh and yield of 1.58 and 0.74 g/g, respectively, were achieved from xylose-rich hydrolysate (41.49 g/L xylose) and synthetic xylose (40.69 g/L) in a 0.5 L bioreactor at an optimum kLa of 0.74 min-1 and 0.68 min-1, respectively. Further, scale-up in 1 L bioreactor using optimum kLa resulted in xylitol productivity (g/Lh) and yield (g/g) of 1.49 & 0.58; 1.57 & 0.74, respectively, from hydrolysate and synthetic xylose. Moreover, scale-up in a 5 L bioreactor using optimum kLa resulted in xylitol yield and productivity of 0.74 g/g and 1.55 g/Lh from synthetic xylose. The successful bioprocess scale-up studies highlight the relevance of lignocellulosic biomass’s valorization to high-valued xylitol.

Investigations on transport behaviours of rotating packed bed for CO2 capture by chemical absorption using CFD simulation

A rotating packed bed (RPB) has been proposed to overcome the limitations of high operating and capital costs involved in conventional columns which are used for chemical absorption-based carbon dioxide (CO2) capture. The design of large-scale RPBs depends on their transport characteristics. Owing to the difficulties in predicting the transport characteristics of RPBs experimentally, Computational Fluid Dynamics (CFD) simulation has been implemented. In this study, a two-dimensional (2D) volume of fluid (VOF) simulation is conducted to predict transport characteristics of RPB including, hydrodynamics, and physical and reactive mass transfers. To predict hydrodynamics of RPBs accurately, the liquid holdup by CFD simulation is compared against experimental prediction, showing a strong agreement between simulation and experimentation. Various liquid phase flow patterns within RPB are observed and these are cross-referenced with findings in the existing literature. Additionally, the impacts of rotational motion and flow rate are further assessed in the study. For the mass transfer performance, the prediction of the volumetric mass transfer coefficient, kLae of the air-water system from CFD simulation is studied. Two different mass transfer theories such as surface renewal theory and penetration theory are studied to predict kLae. It is observed that the kLae from the penetration theory closely follows the trend of the experimental data. Finally, a 2D simulation of the reactive absorption of CO2 by diethylenetriamine (DETA) in RPB is developed and compared with the existing available data in the literature. The present model underpredicts CO2 capture efficiency in RPB, which needs further improvement in reaction kinetics. In general, the present CFD model has the capability of predicting the transport characteristics of RPB.

Characterization Data for the Establishment of Scale-Up and Process Transfer Strategies between Stainless Steel and Single-Use Bioreactors

The reliable transfer of bioprocesses from single-use bioreactors (SUBs) of different scales to conventional stainless steel stirred-tank bioreactors is of steadily growing interest. In this publication, a scale-up study for SUBs with volumes of 200 L and 2000 L and the transfer to an industrial-scale conventional stainless steel stirred-tank bioreactor with a volume of 15,000 L is presented. The scale-up and transfer are based on a comparison of mixing times and the modeling of volumetric mass transfer coefficients kLa, measured in all three reactors in aqueous PBS/Kolliphor solution. The mass transfer coefficients are compared with the widely used correlation of van’t Riet at constant stirrer tip speeds. It can be shown that a van’t Riet correlation enables a robust and reliable prediction of mass transfer coefficients on each scale for a wide range of stirrer tip speeds and aeration rates. The process transfer from single-use bioreactors to conventional stainless steel stirred-tank bioreactors is proven to be uncritical concerning mass transfer performance. This provides higher flexibility with respect to bioreactor equipment considered for specific processes.

Additive manufactured metal lattice structures used as flow-through electrodes in a filter-press electrochemical reactor

This study deals with the electrochemical and hydraulic performances of additive manufactured metal periodic lattice structure electrodes. These electrodes are fabricated by Laser Powder Bed Fusion (LPBF) from the titanium alloy TA6V and two structures have been studied: diagonal and octet-truss. They are integrated, as flow-through electrodes, in an electrochemical filter-press reactor. Current–potential curves are experimentally obtained by linear sweep voltammetry when feeding the reactor with a ferricyanide solution. From the measurement of the limiting current of ferricyanide ions reduction, the volumetric mass transfer coefficient kAe is determined for several flow rates. Numerical simulations of fluid flow and mass transfer in these structures are also performed. Results show high values of kAe for these structures (competing with carbon felt electrodes) while maintaining a high permeability (low flow resistance). The surface roughness, inherent to the additive manufacturing process, is found to induce a low (≲10%) enhancement of mass transfer despite the roughness size (Ra in the range 10-20μm) is close to the average thickness of the diffusion layer (for the investigated fluid velocities). As a result, these electrode structures show promising potential to be used in intensified electrochemical reactors by being further optimized to find the optimal internal dimensions that maximize mass transfer while limiting flow resistance.

Impinging Flow Reactor as a New Approach to Scaling-Up Microreactors for Enhanced Extraction and Separation of Zinc from Cadmium and Manganese

ABSTRACT Despite significant progress in microreactor research, limited throughput hinders their industrial application. The impinging flow method offers a novel approach to scaling up microreactors. In this study, a T-shaped impinging flow reactor was used to investigate the improvement of the throughput of micro-scale devices for the enhanced extraction and separation of zinc from cadmium and manganese using the impinging flow method. Computational fluid dynamics (CFD) simulations were performed to analyze the velocity fields and concentration distributions and gain a better understanding of the mixing and mass transfer phenomena. A comparison of experimental and simulation results under the same conditions was then carried out. Results revealed that decreasing mass transfer efficiency with increased inner diameter, though higher inlet flow rates partially offset this, however beyond a certain threshold, larger channel sizes significantly decrease efficiency. The study also demonstrated that impinging flow reactors exhibit superior volumetric mass transfer coefficients compared to segmented flow microreactors. By increasing the volumetric flow rate and channel inner diameter simultaneously, the millimeter impinging flow reactor achieved the same extraction efficiency as the micrometer segmented flow reactor with a scale-up factor of 1312.5, which indicates a significant increase in device capacity. Overall, this study demonstrates the potential for significant scale-up in device capacity using impinging flow reactors.

Intensification of a biocatalytic oxidation under fine bubble aeration in a rotating bed reactor

The utilization of oxidases suffers from insufficient oxygen availability due to its low solubility in gas-liquid multiphase systems. To overcome this limitation, oxygen is continuously supplied to the reaction medium during the course of the reaction, however, it causes significant gas consumption. In this study, a novel experimental set-up was established by installing a sintered frit porous sparger in the SpinChem® rotating bed reactor. Covalently immobilized glucose oxidase on epoxy-functionalized carriers was used in the rotating bed reactor with an activity yield of the immobilization of over 98%. For fine bubble aeration, the volumetric mass transfer coefficient kLa (67.3 h−1) tripled compared to macrobubble aeration (22.5 h−1), while the volume-specific aeration rate remained constant. A maximum reaction yield of 96.5% was reached. The reaction rate was improved by a factor of 12.9 for the fine bubble aeration compared to macrobubble aeration under identical conditions. With fine bubble aeration, the oxygen consumption was reduced by 87.5% over macrobubble aeration, establishing the same enzyme-specific reaction rates at a comparable kLa. Validation was carried out in repetitive batches, achieving the same glucose oxidase specific activity. This study demonstrates the advantages of fine bubble aeration and presents promising results for addressing the sustainable biotransformation processes.

Simultaneous absorption of H2S, MM and COS into a novel SRSG absorbent using a rotating packed bed

In industries, many gases are required to remove hydrogen sulfide (H2S) and organic sulfur. However, it is still a huge challenge to achieve the efficient and simultaneous removal using a single process. Herein, a novel simultaneous removal sulfide gas (SRSG) absorbent is developed to simultaneously absorb H2S, methyl mercaptan (MM) and carbonyl sulfide (COS). The absorption mechanism between the SRSG absorbent and H2S, MM, COS is explored by quantum chemistry calculations (QCC) and controlled experiments in a rotating packed bed (RPB). Results indicate that the interaction between SRSG and H2S, MM belongs to physical absorption while COS absorption in SRSG obeys two molecule reaction mechanism. Furthermore, the effect of different operating conditions, including rotating speed (N), liquid flow rate (L), gas–liquid ratio (G/L) and temperature (T), on the absorption efficiencies (η) and gas volumetric mass transfer coefficient (KGa) of H2S, MM and COS is systematically investigated. It can be found that both η and KGa are dependent on those operating conditions. The optimal η value for H2S, MM and COS is up to 99.99%, 100%, 100%, respectively. Moreover, nondimensional equations for Sherwood number (Sh) are established, and the calculated and experimental values of Sh(H2S), Sh(MM) and Sh(COS) are in agreement with a deviation within ±13%, ±13%, and ±20%, respectively. These results will provide a valuable potential technique for simultaneously removing acidic gas components from industrial gases.

Ultrasound catalytic ozonation to remove 5-hydroxy-1,3-phthalic acid from strongly alkaline and high-salt solutions: Aiding nuclear waste disposal and human health

As a typical precipitation inhibitor and the main component of plasticizers, 5-hydroxy-1,3-phthalic acid (5-HPA) seriously threatens the nuclear waste disposal and human health. OH, 1O2, and O2− induced by the ultrasound catalytic ozonation (US/O3) process achieves a removal rate of 60.67 % of 5-HPA in strongly alkaline and high-salt solutions within 60 min, which is significantly higher than the O3 alone process. This technology is highly resistant to inorganic anions that coexist in industrial production, but the mineralization process is inhibited. Ozone utilization and mass transfer are significantly improved by ultrasound, including reducing the ozone bubble size by 38 %, increasing the ozone utilization rate from 52 % to 75 %, increasing the volumetric mass transfer coefficient by 61 %, and increasing the specific interfacial area by 60 %, reducing the molar ratio of ozone to TOC from 0.45 to 0.23. Through a combination of Density functional theory (DFT) and GC–MS, four pathways for removing 5-HPA are clearly proposed, which are significantly different from the evolution behavior in acidic systems. The US/O3 system has significant application potential in reducing the threat of 5-HPA to nuclear waste disposal and human health.

A non-aseptic bioprocess for production and recovery of 2,3-butanediol via conversion of crude glycerol and corn steep liquor at pilot-scale

The production and recovery of 2,3-butanediol (BDO) through biodiesel derived glycerol valorization by Klebsiella oxytoca ACA-DC 1581 was holistically optimized with regard to the efficiency and cost of the bioprocess. The absence of thermal treatment of the substrate had no negative effect upon the growth of microorganism and the bioconversion of crude glycerol into BDO, enabling the development of a non-aseptic and lower-cost bioprocess. Both digestate and corn steep liquor (CSL), the main by-products of the biogas and corn industries respectively, successfully served as the sole source of nitrogen, contributing to the complete replacement of more expensive sources (e.g., yeast extract). The biochemical pathway of glycerol catabolism was examined under varying concentrations of dissolved oxygen and BDO production was optimized in a fully aerobic environment (volumetric mass transfer coefficient; kLa = 70.5 1/h.) The glycerol consumption rate was 2.80 g/L/h, the BDO productivity reached 1.12 g/L/h and the yield of BDO produced per unit of glycerol consumed was 0.46 g/g, with these values being among the highest ones reported in the literature for wild-type strains cultivated on crude glycerol. In all fed-batch fermentations, final BDO and acetoin concentration reached ∼80 g/L, while a plateau was observed at ∼68 g/L of BDO. Finally, the culture was carried out efficiently in the pilot-scale reactor (250 L). The salting-out extraction (SOE), consisting of ethanol (24 %) and K2HPO4 (25 %), recovered 91.7 % of BDO from the fermentation medium and was studied for the first time in a glycerol-based medium. The study suggests the potential industrialization of the bioprocess through sustainable, pilot-scale and low-cost bioconversion of biodiesel-derived crude glycerol and CSL or digestate into BDO.

Research on the influence of aeration manners on the mass transfer characteristics of bubbles in multi‐column airlift photobioreactor

AbstractMass transfer of bubbles is important in microalgae cultivation. In this study, aiming to improve the microalgae culturing efficiency, computational fluid dynamics (CFD) was adopted to study the influence of the aeration manners on mass transfer of bubbles within ascending columns in multi‐column airlift photobioreactor (PBR) and the hydrodynamic conditions within the PBR under different aeration manners. In addition, the bubble generation time, the detachment diameter, and the average volumetric mass transfer coefficient of bubbles in ascending columns were analyzed. Furthermore, the experimental results were compared with the simulation results obtained from microalgae cultivation. The results showed that the whole aeration manner yields the lowest mixing strength and mass transfer efficiency of bubbles at an aeration rate of 0.2 vvm. Conversely, both the mixing strength of the liquid and mass transfer coefficient of bubbles were enhanced under the half and alternate aeration manners. However, the results demonstrated that the distribution of the flow field was not uniform under the half aeration manner and there were obvious high‐speed and low‐speed zones. In contrast, the flow field distribution in the PBR was more uniform under the alternate aeration manner, which was suitable for microalgae cultivation at high concentration. This study effectively enhanced the mixing strength and CO2 transfer rate in the PBR.

Experimental study on the effect of process parameters on postcombustion CO2 capture using rotating packed bed technology

AbstractEnvironmental issues are the most discussed in today's industrialized world, and this has always been associated with the emission of greenhouse gases. CO2 emissions, especially from power plants, are considered the major greenhouse gas source. Capturing CO2 from large emission sources is necessary to address the worst impacts of climate change, including more frequent and severe droughts, heat waves, and intermittent rainfall. Conventional post‐combustion CO2 capture has always been questioned because of its high impact on energy costs. Rotating packed bed technology has shown the potential to reduce the cost of CO2 capture. This paper presents an experimental study on an in‐house designed rotating packed bed absorber for the capture of CO2 from a flue gas stream. Effects of process parameters such as rotating speed, liquid‐to‐gas ratio, and monoethanolamine (MEA) concentration on CO2 capture efficiency and overall volumetric mass transfer coefficient were studied. The study showed that as rotor speed increased, the CO2 capture efficiency increased, this can be attributed to higher rotor speed, resulting in more droplet flow, indicating an increase in the area of contact between the flue gas and the MEA solvent. Also, as the concentration of MEA increased CO2 capture efficiency increased, since an increase in concentration results in an increase in the rate of reaction. Finally, the study showed that a rotating packed bed absorber is an efficient unit for CO2 capture since it enhances mass transfer performance.