Intensification of CO₂ Capture by Monoethanolamine Solution in a Rotating Packed Bed Reactor Equipped with High Frequency Ultrasonic Transducers

Intensification of CO₂ Capture by Monoethanolamine Solution in a Rotating Packed Bed Reactor Equipped with High Frequency Ultrasonic Transducers

Mahdi Hefzi Lotfabadi ^a, Masoud Shirzadi Ahoudashti ^a, Mahdieh Abolhasani [*]^,a

^a Faculty of Chemical, Petroleum and Gas Engineering, Semnan University, Semnan, Iran

1. Introduction

Process intensification (PI) involves instruments and developing methods that leads to significant improvement in equipment and process designing and a substantial decrease in equipment size, and energy consumption, which finally results in lower cost and beneficial production, and higher production capacity [1]. PI is divided into two parts: equipment and methods. Rotating Packed Bed (RPB) reactor and ultrasonic waves are one of the most popular equipment and method of PI technologies [2]. The RPB as a high efficiency PI equipment was innovated in 1981 by Mallinson, and Ramshaw [3]. This device replaces a high centrifugal force with gravitational force and achieves high efficiency in a small volume. The RPB technology is suitable for separation processes like absorption [4], extraction [5], distillation [6], and other processes such as polymerization [7], oxidation [8] and nanoparticle synthesis [9]. By taking advantage of both high centrifugal force and rotational speed, the RPBs can be employed in systems involving viscous liquids and in reactions with short contact time [10]. In RPBs, due to high centrifugal forces, the liquid film changes into tiny droplets which leads to the enhancement of the interfacial area and, finally increase in the mass transfer rate [11].

In comparison with conventional packed beds, the RPBs have specific advantages such as higher efficiency [12, 13], significantly smaller apparatus volumes [13, 14], and lower energy consumption. As a result, from an economic point of view, The RPBs have the lower investment and operational cost comparing the conventional packed beds [13, 14]. Although various successful applications of RPBs have been reported in the industrial scale, the technology has not yet reached its full industrial maturity [15, 16]. The number of industrial-scale applications of RPBs is very limited [17], but rapidly growing, especially in gas absorption processes. A possible reason for the limited number of industrial applications of RPBs is the low number of scale-up investigations [17]. The scale-up investigation of the RPBs has been reported in a few studies [17, 18].

As mentioned, ultrasound is among the most popular methods of PI technologies [2]. Ultrasound is a mechanical wave with a frequency above 20 kHz [19-21]. Acoustic cavitation is the significant effect of the wave propagation in the liquid medium, which induces acoustic streaming, microstreaming and heating [22, 23]. Acoustic cavitation is the process of bubble formation, growth, and collapse due to variations in the wave pressure [24]. The size of the cavitation bubbles depends on the wave frequency [25, 26]. There are two types of cavitation bubbles: stable, and transient cavitation bubbles [27, 28]. Transient cavitation bubbles exist for less than one cycle [27], which are created by low frequency waves. Transient bubbles are not very small and they can decompose to smaller bubbles.

The frequency spectrum, above 1 MHz, is named “low power ultrasound” (< 10W) which does not affect the propagation medium, and is mainly utilized for medical diagnosis [27]. These waves increase turbulence and also generate stable cavitation bubbles, acoustic streams, and acoustic fountains [28, 29]. Stable bubbles do not collapse for a long time [27, 28]. The formation of the stable bubbles creates another important effect called microstreaming. The creation of the high speed unidirectional currents of the stable bubbles causes the momentum gradients and the fluid currents, which are called the acoustic streaming [27] These streams create the acoustic fountain (deformation) at the gas-liquid interface [26, 27, 29]. Whatever the ultrasonic frequency is higher, the liquid droplet will be smaller, and the interfacial area will increase, which causes enhancement in mass transfer rate [30] or intensification of the physical and chemical processes. Using high frequency ultrasound is an efficient way to enhance absorption processes.

Today, industrialization and the use of fossil fuels have caused the emission of greenhouse gases and global warming. Therefore, it is necessary to use alternative energy sources and reduce greenhouse gas emissions [31]. CO₂ is one of the most important emitted greenhouse gases. Therfore, CO₂ capture is an important issue, and finding new and efficient techniques to intensify it is crucial. As CO₂ absorption is a significant factor for reducing global warming, researchers are looking for efficient methods to capture and store CO₂ [32], such as absorption [33]. As mentioned above, respect to the specific characteristics of the RPB in absorption and separation, application of RPB in CO₂ capturing attracted wide attention [34-40]. In 2011, Cheng and Tan [34], studied about removal of CO₂ from indoor air by alkanolamines in an RPB reactor for a long time to decrease the CO₂ concentration from 1000 ppm to 100 ppm. They showed that the RPB was more efficient and preferable than a conventional packed bed. In 2014, Kang et al. [35] investigated the CO₂ capturing in an RPB using diluted ammonia. They found that the height of the transfer unit (HTU) of the RPB was smaller than a conventional packed bed, which was equivalent to that and ultimately resulted in a reduction in equipment size and costs. In 2017, Wu et al. [36], studied CO₂ capture from power plants by piperazine (PZ) and diethylenetriamine (DETA) solution in an RPB. Their experiments showed that the PZ and DETA solutions compared to traditional monoethanolamine (MEA) solutions were more efficient. In 2007, jassim et al. [37] studied about CO₂ absorption and desorption in an RPB by aqueous solution. They found that the CO₂ penetration in an MEA concentration up to 30 %w decreased.

Applications of ultrasound for increasing CO₂ absorption and saving CO₂ capture and storage (CCS) costs have been studied in recent years [2, 30, 41]. In 2017, Tay et al. [41] showed that the CO₂ absorption rate into MEA solution increases dramatically in the presence of high frequency ultrasound. In addition, they suggested that the high frequency ultrasounds lead to a high mass transfer coefficient in a compact design due to the formation of acoustic fountains and convective dynamics. In 2017, Tay et al. [30] studied the CO₂ absorption with a potassium carbonate without any promoter in the presence of high frequency ultrasound. They found that, the reaction rate assisted by ultrasonic waves was about 32 times higher than that without ultrasound. In addition, the reaction time to achieve 0.9 loadings (CO₂ mol/ K₂CO₃ mol) reduced to 400s. Finally, they showed that high frequency ultrasonic waves are an effective equipment for increasing the absorption rate in a slow kinetic reaction. In 2018, Luo et al. [2] studied the effective interfacial area and volumetric liquid-side mass transfer coefficient (K_La) using a NaOH-CO₂ mass transfer system in an RPB reactor under 20 kHz ultrasound. They reported that the  under ultrasound field enhanced 5.5% compared with no ultrasound conditions.

In the above studies, the use of RPB and ultrasound in the CO₂ absorption process has been investigated separately, except in the work of Luo et al. [2]. In their study, low frequency ultrasound was used in an RPB reactor. Continuing our previous work [42] and the work of Luo et al. [2], we decided to use high frequency ultrasonic waves in an RPB with different packing and different CO₂ absorbent. For this purpose, ultrasonic transducers with a frequency of 1.7 MHz were selected, which are known as ultrasonic atomizer humidifiers. These transducers creat cold boiling [28].

In this study, we aimed to investigate the simultaneous effect of an RPB equipped with blade packing as PI equipment, and high frequency ultrasound as a PI method on the CO₂ absorption process. Therefore, measurement of CO₂ absorption percent (E), and overall volumetric gas-side mass transfer coefficient (k_Ga) under different operational conditions was performed using an MEA-CO₂ mass transfer system.

2. Material and Experimental Methods

2.1. Development of RPB Reactor

In this study, an RPB reactor with a plexiglass casing was used. The rotor is equipped with 12 stainless steel blades. Four 1.7 MHz ultrasonic transducers with a diameter of 20 mm were embedded at the bottom of the reactor. To ensure the presence of liquid on the transducers and to benefit from ultrasound effects such as cavitation, acoustic fountain, and fogging, the rotor was installed upside down. Another advantage of this structure is comfortable sealing. Two distributers with a hole diameter of 1 mm were used to distribute the liquid in the packing symmetrically. Figure 1 shows the different parts and dimensions of the RPB reactor.

2.2. Experimental Method

The schematic of the experimental setup for the CO₂ absorption process is depicted in Figure 2. The utilized absorbent was MEA with a concentration of 1-4 mol/L and a volume flow rate of 20-120 L/h. The gas mixture containing CO₂ and N₂, with a volume flow rate of 2500-4000 L/h, entered the reactor and reacted with the absorbent. The inlet CO₂ concentration was 10000-40000 ppm. The outlet gas was analyzed by CO₂ sensor (s8 alarm 5% (senseair)). The CO₂ amount in the outlet gas was used to calculate the overall volumetric gas-side mass transfer coefficient by the following equation [42– 45]:

where Q_G is the volumetric gas flow rate, Z_b is the height of packing, and R_i and R_o are the inner and outer diameter of packing, respectively. Moreover, C_i and C_o are the CO₂ concentration in the inlet and outlet gas streams. The CO₂ removal efficiency can be determined by equation (2):

(a)

(b)

Figure 1. (a) The real view of the RPB reactor, and (b) schematic view of the reactor and dimensions (mm).

1. Motor, 2. The casing of the RPB reactor, 3. Shaft, 4. Blade packings, 5. Rotating bed, 6. Distributers, 7. Ultrasonic transducers,
   8. Piezoelectric actuator, 9. Power supply, 10. CO₂ and N₂ gas cylinders, 11. Valves, 12. Rotameter,
   13. MEA solution tank, 14. Pump, 15. Waste tank, 16. CO₂ analyzer,17. Computer.

Figure 2. Schematic diagram of the CO₂ capture system

The operating pressure of the RPB reactor was 1 atm. All experiments were carried out at 25±2 °C with three repetitions. The ultrasonic power was measured by a calorimetric experiment in a batch flow mode [19, 20]. The concentration of CO₂ in the outlet stream was measured with a standard deviation of less than 3 %. Effects of the rotational speed of the bed (N), liquid flow rate (Q_L), absorbent concentration (C_MEA), gas flow rate (Q_G), and CO₂ concentration on K_Ga and E were investigated.

3. Result and Discussion

3.1. Effect of Rotational Speed on K_Ga

Figure 3 presents the effect of N on K_Ga. In these experiments, Q_G, C_MEA, CO₂ percent, Q_L, and P_us were set at 3500 L/h, 1 mol/L, 2 vol%, 50 L/h, and 22.5 W, respectively. As can be seen, enhancing the rotational speed increases the volumetric gas side mass transfer coefficient. To describe this issue, we can mention that, higher rotational speed causes more collisions between rotating packed bed and absorbent solution that leads to thinner liquid films and their better distribution. These tiny droplets and the thin liquid film increase the interfacial area and improve the overall mass transfer coefficient. Moreover, the CO₂ absorption increased in ultrasonic presence. These waves cause creating tiny droplets, more interfacial area, and finally increase the removal efficiency. Also, a convergence in the diagram at high rotational speeds, it means that the centrifugal force is overcoming ultrasonic effects. For a better evaluation of the effects of high frequency ultrasound on CO₂ absorption, the relative volumetric gas-side mass transfer coefficient, , is defined as follows [2]:

where 0 and us are referred to as no ultrasound and ultrasound conditions. In these experiments, for N of 400 –1600 rpm, the values of  change from 32.3 % to 3.3 %, while E varies from 14.8 % to 28.9% for non-ultrasonic assisted RPB reactor (NUAR) to 19.1%- 29.7% for ultrasonic assisted RPB reactor (UAR).

Figure 3. Effect of rotational speed on K_Ga.

3.2. Effect of Liquid Flow Rate on K_Ga

Figure 4 showed the effect of Q_L on K_Ga, while Q_G, C_MEA, CO₂ percent, N, and P_us were set at 3500 L/h, 1 mol/L, 2 vol%, 1200 rpm, and 22.5 W, respectively. K_Ga and the removal efficiency are enhanced by increasing the liquid flow rate due to decreasing liquid-side mass transfer resistance. In addition, the wetting of each unit of packing increases which is favorable for CO₂ absorption. On the other hand, increasing the liquid flow rate also has a negative aspect that reduces the residence time, but it’s negligible. Also, the acoustic fountain formed by ultrasonic waves can return the absorbent solution from the bottom of the reactor to the packing zone and increases each unit of wetted packing, that is desirable for capturing process. In these experiments, for Q_L of 20 –120 L/h, the values of  change from 16.9 % to 5.0 %, while E varies from 24.1 %– 33.2 % for NUAR to 27.6%- 34.6% for UAR.

Figure 4. Effect of liquid flow rate on K_Ga.

3.3. Effect of MEA Concentration on K_Ga

Figure 5 summarizes the effect of MEA concentration on K_Ga, while Q_G, Q_L, CO₂ percent, N, and P_us were set at 3500 L/h, 50 L/h, 2 vol%, 1200 rpm, and 22.5 W, respectively.

The results show that by increasing the C_MEA, the K_Ga and removal efficiency enhance. For the constant amount of CO₂, there is more amount of MEA that causes enhancement in mass transfer driving force and finally a significant increase in removal efficiency.

On the other hand, ultrasound can spread the MEA droplets, which still didn't react completely with CO₂, to the packing zone by the acoustic fountain and fogging phenomena, and finally assist in improving the removal efficiency and K_Ga.

In these experiments, for C_MEA of 1- 4 mol/L, the values of  change from 9.8 % to 6.7 %, while E varies from 26.0 %– 37.7 % for NUAR to 28.1%- 39.6% for UAR.

Figure 5. Effect of MEA concentration on K_Ga.

3.4. Effect of Gas Flow Rate on K_Ga

Figure 6 shows the effect of Q_G on K_Ga. In this section, CO₂ percent, Q_L, C_MEA, N, and P_us were 2 vol%, 50 L/h, 1 mol/L, 1200 rpm, and 22.5 W, respectively. The gas flow rate enhancement has both positive and negative effects. Decreasing the gas-side mass transfer resistance is the positive effect and decreasing the residence time is the negative effect, but it’s negligible. Moreover, ultrasound can enhance the K_Ga. Ultrasonic waves return some of the MEA solution to the packing zone, which reduces the negative effect of gas flow rate enhancement (residence time) by increasing the volume of liquid in the packing zone, in the time interval between gas entering and exiting the reactor. In these experiments, for Q_G of 2500 -4000 L/h, the values of  change from 9.3 % to 13.4 %, while E varies from 31.3 % - 23.9 % for NUAR to 33.6%- 26.6% for UAR.

Figure 6. Effect of gas flow rate on K_Ga.

3.5. Effect of CO₂ Concentration on K_Ga

Figure 7 illustrates the effect of CO₂ concentration on K_Ga, while Q_G, Q_L, C_MEA, N, and P_us were set at 3500 L/h, 50 L/h, 1 mol/L, 1200 rpm, and 22.5 W, respectively. The effect of increasing this parameter on CO₂ absorption is the opposite of increasing MEA concentration. It means that for a specific amount of MEA, there are more CO₂ molecules that should be captured. In this case (high CO₂ concentration), thermodynamics (solubility) would govern the removal efficiency instead of kinetics which finally caused a decrease in removal efficiency [46]. Furthermore, ultrasonic effects on process efficiency are similar to other parameters. In these experiments, for CO₂ concentration of 10000 - 40000 ppm (1%-4%), the values of  change from 7.4 % to 16.3 %, while E varies from 36.4 % to 22.0 % for NUAR to 38.5%- 25.0 % for UAR.

According to the above evidence, despite the very low residence time of the liquid droplets in the RPB reactor, 1.7 MHz ultrasound can significantly enhance CO₂ absorption and K_Ga. Using the above results,  (the average arithmetic value of ) was obtained 11.4%, respectively.

Figure 7. Effect of CO₂ concentration on K_Ga.

3.6. Comparison of the RPB Performance in This Study with Other Works

The comparison of the performance of the present reactor with other existing reactors with almost similar structures and conditions is done in Table 1. Although the comparison is very difficult due to the different structures of the reactors and their internal components and different operating conditions. As it was mentioned, for the first time, Luo et al [2] studied the effect of ultrasound on mass transfer coefficient using a NaOH-CO₂ system in an RPB reactor. As they reported K_La, it was not possible to compare our study with them. From Table 1, it can be seen that in almost similar conditions, relatively more K_Ga was obtained in the present work. For example, the maximum K_Ga of the present study is 20% more than the K_GA in the work of Lin et al. [48], which is a significant increase considering as the percentage of carbon dioxide in the present study is twice. In addition, in terms of comparison with the work [42], in the same conditions, the reactor equipped with ultrasonic waves has achieved higher coefficients. Also, in the almost similar conditions, the maximum K_Ga of the present study is 4.17 times the K_Ga reported in the work of Mohammadi and Heidari [45].

Table 1. Comparison of the RPB performance in this study with other works

4. Conclusions

In this study, the investigation of the effect of high frequency ultrasonic waves on CO₂ absorption in the RPB reactor with twelve blade packings was done. Four 1.7 MHz ultrasonic transducers were embedded in the bottom of the reactor. All experiments were repeated in the absence and presence of ultrasound. The CO₂ absorption percent (E), and the volumetric gas-side mass transfer coefficient (k_Ga) were investigated by using an MEA-CO₂ mass transfer system. The effects of different parameters such as rotational speed (400–1600 rpm), liquid flow rate (20 –120 L/h), MEA concentration (1- 4 mol/L), gas flow rate (2500- 4000 L/h), and CO₂ concentration (1- 4 vol%) have been investigated. According to the evidence, despite the very low residence time of the liquid droplets in the RPB reactor, 1.7 MHz ultrasound can significantly enhance CO₂ absorption. The following results have been obtained:

• The removal efficiency increased with increasing gas and liquid flow rate, and rotational speed, as well as MEA concentration.
• With increasing CO₂ concentration, absorption efficiency decreased.
• (The average arithmetic value of ) was obtained 11.4% under the ultrasound field.
• The average CO₂ removal efficiency was enhanced from 27.4 % in the absence of ultrasound to 29.8% in the presence of ultrasound.
• High frequency ultrasound can enhance CO₂ absorption, even in high efficiency equipment like RPBs.

Nomenclature

References

[1]    Stankiewicz, A.I. and Moulijn, J.A., 2000. Process intensification: Transforming chemical engineering, Chemical Engineering Progress, 96, pp.22-34

[2]    Luo, Y., Luo, J.Z., Yue, X.J., Song, Y.J., Chu, G.W., Liu, Y., Le, Y. and Chen, J.-F., 2018. Feasibility studies of micromixing and mass-transfer in an ultrasonic assisted rotating packed bed reactor. Chemical Engineering Journal, 331, pp.510–516.

[3]    Ramshaw, C. and Mallinson, R.H., US 4,283,255, Mass transfer process, United States Pat 1981:12.

[4]    Zhang, L.L., Wang, J.X., Xiang, Y., Zeng, X.F. and Chen, J.F., 2011. Absorption of carbon dioxide with ionic liquid in a rotating packed bed contactor: Mass transfer study. Industrial & Engineering Chemistry Research, 50, pp.6957–6964.

[5]    Liu, H.S., Lin, C.C., Wu, S.C. and Hsu, H.W., 1996. Characteristics of a rotating packed bed. Industrial & Engineering Chemistry Research, 35(10), pp.3590–3596.

[6]    Kelleher, T. and Fair, J.R., 1996. Distillation Studies in a High-Gravity Contactor. Industrial & Engineering Chemistry Research, 35(12), pp.4646–4655.

[7]    Chen, J.F., Gao, H., Zou, H.K., Chu, G.W., Zhang, L., Shao, L., Xiang, Y. and Wu, Y.-X., 2010. Cationic polymerization in rotating packed bed reactor: Experimental and modeling. AIChE Journal, 56(4), pp.1053-1062.

[8]    Lin, C.C. and Liu, W.T., 2003. Ozone oxidation in a rotating packed bed, Journal of Chemical Technology & Biotechnology, 78, pp.138–141.

[9]    Kang, F., Wang, D., Pu, Y., Zeng, X.F., Wang, J.X. and Chen, J.F., 2018. Efficient preparation of monodisperse CaCO₃ nanoparticles as overbased nanodetergents in a high-gravity rotating packed bed reactor. Powder Technology, 325, pp.405–411.

[10] Neumann, K., Gladyszewski, K., Groß, K., Qammar, H., Wenzel, D., Górak, A. and Skiborowski, M., 2018. A guide on the industrial application of rotating packed beds. Chemical Engineering Research and Design, 134, pp.443–462.

[11] Thiels, M., Wong, D.S.H., Yu, C.H., Kang, J.L., Jang, S.S. and Tan, C.S., 2016. Modelling and Design of Carbon Dioxide Absorption in Rotating Packed Bed and Packed Column. IFAC-PapersOnLine, 49, pp.895–900.

[12] Sheng, M., Xie, C., Zeng, X., Sun, B., Zhang, L., Chu, G., Luo, Y., Chen, J.-F. and Zou, H., 2018. Intensification of CO₂ capture using aqueous diethylenetriamine (DETA) solution from simulated flue gas in a rotating packed bed. Fuel, 234, pp.1518-1527.

[13] Liu, Z., Esmaeili, A., Zhang, H., Xiao, H., Yun, J. and Shao, L., 2021. Carbon dioxide absorption with aqueous amine solutions promoted by piperazine and 1-methylpiperazine in a rotating zigzag bed, Fuel, 302, 121165.

[14] Borhani, T.N., Oko, E. and Wang, M., 2018. Process modelling and analysis of intensified CO₂ capture using monoethanolamine (MEA) in rotating packed bed absorber. Journal of Cleaner Production, 204, pp.1124–1142.

[15] Lukin, I., Pietzka, L., Groß, K., Górak, A. and Schembecker, G., 2020. Economic evaluation of rotating packed bed use for aroma absorption from bioreactor off-gas. Chemical Engineering and Processing- Process Intensification, 154, 108011.

[16] Neumann, K., Gladyszewski, K., Groß, K., Qammar, H., Wenzel, D., Górak and A., Skiborowski, M., 2018. A guide on the industrial application of rotatingpacked beds. Chemical Engineering Research and Design, 134, pp.443-462.

[17] Groß, K., de Beer, M., Dohrn, S. and Skiborowski, M., 2020. Scale-Up of the Radial Packing Length in Rotating Packed Beds for Deaeration Processes. Industrial & Engineering Chemistry Research, 59(23), pp. 11042-11053.

[18] Zhao, R.-H., Li, C.-P., Guo, F. and Chen, J.-F., 2007. Scale-up Preparation of Organized Mesoporous Alumina in a Rotating Packed Bed. Industrial & Engineering Chemistry Research, 46(10), pp.3317-3320.

[19] Abolhasani, M., Karami, A. and Rahimi, M., 2015. Numerical Modeling and Optimization of the Enhancement of the Cooling Rate in Concentric Tubes under Ultrasound Field. Numerical Heat Transfer, Part A: Applications, 67, pp.1282–1309.

[20] Dehbani, M., Rahimi, M., Abolhasani, M., Maghsoodi, A., Afshar, P.G., Dodmantipi, A.R. and Alsairafi, A.A., 2014. CFD modeling of convection heat transfer using 1.7 MHz and 24 kHz ultrasonic waves: A comparative study. Heat and Mass Transfer, 50, pp.1319–1333.

[21] Abolhasani, M., Rahimi, M., Dehbani, M. and Shabanian, S.R., 2012. CFD Modeling of Low, Medium and High Frequency Ultrasound Waves Propagation Inside a Liquid Medium. The 4rd National Conference on CFD Applications in Chemical & Petroleum Industries.

[22] Aghapour Aktij, S., Taghipour, A., Rahimpour, A., Mollahosseini, A. and Tiraferri, A., 2020. A critical review on ultrasonic-assisted fouling control and cleaning of fouled membranes. Ultrasonics, 108, 106228.

[23] Zheng, J., Guo, Y., Zhu, L., Deng, H. and Shang, Y., 2021. Cavitation effect in two-dimensional ultrasonic rolling process. Ultrasonics, 115, 106456.

[24] Viriyananon, K., Mingbunjerdsuk, J., Thungthong, T. and Chaiworapuek, W., 2021. Characterization of heat transfer and friction loss of water turbulent flow in a narrow rectangular duct under 25–40 kHz ultrasonic waves, Ultrasonics, 114, 106366.

[25] Parvizian, F., Rahimi, M., Hosseini, S.M., Madaeni, S.S. and Alsairafi, A.A., 2012. The Effect of High Frequency Ultrasound on Diffusion Boundary Layer Resistance in Ion-Exchange Membrane Transport, Desalination, 286, pp.155-165.

[26] Abolhasani, M., Rahimi, M., Dehbani, M. and Alsairafi, A.A., 2012. CFD Modeling of Heat Transfer by 1.7 MHz Ultrasound Waves, Numerical. Heat Transfer. part A-Application. 62, pp. 822-841.

[27] Legay, M., Gondrexon, N., Le Person, S., Boldo, P. and Bontemps, A., 2011. Enhancement of heat transfer by ultrasound: Review and recent advances. International Journal of Chemical Engineering, 2011.

[28] Rahimi, M., Abolhasani, M. and Azimi, N., 2015. High frequency ultrasound penetration through concentric tubes: Illustrating cooling effects and cavitation intensity. Heat and Mass Transfer, 51, pp.587-599.

[29] Abolhasani, M., Rahimi, M., Dehbani, M. and Alsairafi, A.A., 2012. CFD modeling of heat transfer by 1.7 MHz ultrasound waves, Numerical Heat Transfer, Part A: Applications, 62, pp.822–841.

[30] Tay, W.H., Lau, K.K. and Shariff, A.M., 2017. High performance promoter-free CO₂ absorption using potassium carbonate solution in an ultrasonic irradiation system. Journal of CO₂ Utilization, 21, pp.383–394.

[31] Bahoosh, R., Sedeh Ghahfarokhi, M. and Saffarian, M.R., 2018. Energy and Exergy Analyses of a Diesel Engine Running on Biodiesel Fuel. Journal of Heat and Mass Transfer Research, 5, pp. 95-104.

[32] Lee, S.Y. and Park, S.J., 2015. A review on solid adsorbents for carbon dioxide capture, Journal of Industrial and Engineering Chemistry, 23, pp.1 –11.

[33] Hu, G., Smith, K.H., Wu, Y., Mumford, K.A., Kentish, S.E., and Stevens, G.W., 2018. Carbon dioxide capture by solvent absorption using amino acids: A review, Chinese Journal of Chemical Engineering, 26(11), pp. 2229–2237.

[34] Cheng, H.H. and Tan, C.S., 2011. Removal of CO₂ from indoor air by alkanolamine in a rotating packed bed. Separation and Purification Technology, 82, pp.156–166.

[35] Kang, J.L., Luo, Z.J., Liu, J.L., Sun, K., Wong, D.S.H., Jang, S.S., Tan, C.-S. and Shen, J.-F., 2014. Experiment and modeling studies on absorption of CO₂ by dilute ammonia in rotating packed bed. Energy Procedia, 63, pp.1308–1313.

[36] Wu, T.W., Hung, Y.T., Chen, M.T. and Tan, C.S., 2017. CO₂ capture from natural gas power plants by aqueous PZ/DETA in rotating packed bed. Separation and Purification Technology, 186, pp.309–317.

[37] Jassim, M.S., Rochelle, G., Eimer, D. and Ramshaw, C., 2007. Carbon dioxide absorption and desorption in aqueous monoethanolamine solutions in a rotating packed bed, Industrial & Engineering Chemistry Research, 46, pp. 2823–2833.

[38] Lin, C.C. and Chu, C.R., 2015. Feasibility of carbon dioxide absorption by NaOH solution in a rotating packed bed with blade packings. International Journal of Greenhouse Gas Control, 42, pp.117–123.

[39] Yu, C.H., Wu, T.W. and Tan, C.S., 2013. CO₂ capture by piperazine mixed with non-aqueous solvent diethylene glycol in a rotating packed bed, International Journal of Greenhouse Gas Control, 19, pp.503–509.

[40] Lin, C.C. and Chen, Y.W., 2011. Performance of a cross-flow rotating packed bed in removing carbon dioxide from gaseous streams by chemical absorption. International Journal of Greenhouse Gas Control, 5, pp.668–675.

[41] Tay, W.H., Lau, K.K. and Shariff, A.M., 2017. High frequency ultrasonic-assisted chemical absorption of CO₂ using monoethanolamine (MEA). Separation and Purification Technology, 183, pp.136–144.

[42] Shirzadi Ahou Dashti, M. and Abolhasani, M., 2020. Intensification of CO₂ capture by monoethanolamine solution containing TiO₂ nanoparticles in a rotating packed bed, International Journal of Greenhouse Gas Control, 94, 102933.

[43] Jassim, M.S., 2002. Process Intensification: Absorption and Desorption of Carbon Dioxide from Monoethanolamine Solutions Using Higee Technology, (PhD Thesis, Newcastle University).

[44] Lin, C.C. and Chu, C.R., 2015. Mass transfer performance of rotating packed beds with blade packings in carbon dioxide absorption into sodium hydroxide solution. Separation and Purification Technology, 150, pp.196-203.

[45] Mohammadi Nouroddinvand, V. and Heidari, A., 2021. Experimental study of absorption with MEA solution in a novel Arc-RPB. Chemical Engineering and Processing- Process Intensification, 165, 108450.

[46] Aroonwilas, A. and Veawab, A., 2004. Characterization and comparison of the CO₂ absorption performance into single and blended alkanolamines in a packed column. Industrial & Engineering Chemistry Research, 43, 9, pp.2228–2237.

[47] Lin, C.C., Liu, W.T., and Tan, C.S., 2003. Removal of carbon dioxide by absorption in a rotating packed bed. Industrial & Engineering Chemistry Research, 42, pp.2381-2386.

[48] Lin, C.C. and Kuo, Y.W., 2016. Mass transfer performance of rotating packed beds with blade packings in absorption of CO₂ into MEA solution. International Journal of Heat and Mass Transfer, 97, pp.712-718.

[*]Corresponding Author: Mahdieh Abolhasani

   Email: m.abolhasani@semnan.ac.ir