scholarly journals Droplet Characteristics of Rotating Packed Bed in H2S Absorption: A Computational Fluid Dynamics Analysis

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 724
Author(s):  
Wang ◽  
Wu ◽  
Yang ◽  
Wang ◽  
Liu ◽  
...  
Keyword(s):  
Residence Time ◽  
Droplet Diameter ◽  
Packed Bed ◽  
Droplet Velocity ◽  
Radial Position ◽  
Selective Absorption ◽  
Rotating Speed ◽  
Initial Droplet ◽  
Rotating Packed Bed ◽  
Computational Fluid Dynamics Analysis

Rotating packed bed (RPB) has been demonstrated as a significant and emerging technology to be applied in natural gas desulfurization. However, droplet characteristics and principle in H2S selective absorption with N-methyldiethanolamine (MDEA) solution have seldom been fully investigated by experimental method. Therefore, a 3D Eulerian–Lagrangian approach has been established to investigate the droplet characteristics. The discrete phase model (DPM) is implemented to track the behavior of droplets, meanwhile the collision model and breakup model are employed to describe the coalescence and breakup of droplets. The simulation results indicate that rotating speed and radial position have a dominant impact on droplet velocity, average residence time and average diameter rather than initial droplet velocity. A short residence time of 0.039–0.085 s is credited in this study for faster mass transfer and reaction rate in RPB. The average droplet diameter decreases when the initial droplet velocity and rotating speed enhances. Restriction of minimum droplet diameter for it to be broken and an appropriate rotating speed have also been elaborated. Additional correlations on droplet velocity and diameter have been obtained mainly considering the rotating speed and radial position in RPB. This proposed formula leads to a much better understanding of droplet characteristics in RPB.

scholarly journals Polymerization of Isobutylene in a Rotating Packed Bed Reactor: Experimental and Modeling Studies

2021 ◽  
Vol 11 (21) ◽  
pp. 10194
Author(s):  
Wenhui Hou ◽  
Wei Wang ◽  
Yang Xiang ◽  
Yingjiao Li ◽  
Guangwen Chu ◽  
...  
Keyword(s):  
Strong Dependence ◽  
Average Molecular Weight ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Mixing Efficiency ◽  
Polymerization Temperature ◽  
Analysis Method ◽  
Rotating Speed ◽  
Rotating Packed Bed ◽  
The Given

Polymerization of isobutylene (IB) for synthesizing highly reactive polyisobutylene (HRPIB) is characterized by a complicated fast intrinsic reaction rate; therefore, the features of its products exhibit a strong dependence on mixing efficiency. To provide uniform and efficient mixing, a rotating packed bed was employed as a reactor for polymerization of IB. The effects of operating parameters including polymerization temperature (T), rotating speed (N) and relative dosage of monomers and initiating systems ([M]0/[I]0) on number-average molecular weight (Mn) of HRPIB were studied. HRPIB with Mn of 2550 g·mol−1 and exo-olefin terminal content of 85 mol% were efficiently obtained at suitable conditions as T of 283 K, N of 1600 rpm and [M]0/[I]0 of 49. Moreover, the Mn can be regulated by changing T, N and [M]0/[I]0. Based on the presumptive-steady-state analysis method and the coalescence–redispersion model, a model for prediction of the Mn was developed and validated, and the calculated Mn values agreed well with experimental results, with a deviation of ±10%. The results demonstrate that RPB is a promising reactor for synthesizing HRPIB, and the given model for Mn can be applied for the design of RPB and process optimization.

scholarly journals Continuous Carbonation for Synthesis of Pseudo-Boehmite by Using Cross-Flow Rotating Packed Bed through the Reaction of NaAlO2 Solution with CO2 Gas

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 263 ◽  
Author(s):  
Xiaojing Ren ◽  
Youzhi Liu ◽  
Longxin Miao
Keyword(s):  
Electron Microscopy ◽  
Cross Flow ◽  
Packed Bed ◽  
High Specific Surface Area ◽  
Liquid Ratio ◽  
Co2 Gas ◽  
Rotating Speed ◽  
Full Contact ◽  
Rotating Packed Bed ◽  
Bet Analysis

This research established a novel method for the preparation of pseudo-boehmite (PB) via a continuous carbonation of CO2 gas and a NaAlO2 solution in a cross-flow rotating packed bed (CF-RPB). In the CF-RPB, the NaAlO2 solution can be sheared into fine liquid filaments and droplets, and react in full contact with the CO2 gas. Effects of synthesis parameters, including the concentration of the NaAlO2 solution, the gas–liquid ratio, the rotating speed of the CF-RPB, and the final pH of the solution on the crystal structure of PB, were fully investigated. A series of characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) analysis, were carried out to explain the evaluation results and to find the relationship between PB properties and the synthetic conditions. The results showed that PB with a high specific surface area (495 m2/g) and large pore volume (2.125 cc/g) can be obtained when the concentration of the NaAlO2 solution was 0.1 mol/L, the gas–liquid ratio was 3:1, the rotating speed of RPB was 600 rpm, and the final pH was around 10.5. PB obtained by this method had a higher quality compared with that using a stirred tank reactor. Moreover, the continuous carbonation can be efficiently batch-produced, which provided a new idea for an industrial application.

Numerical Simulation of Counter-Current Flow Field in Double Packing Rotating Packed Bed

2013 ◽  
Vol 561 ◽  
pp. 672-676
Author(s):  
De Dong Hu ◽  
Wen Yan Shan ◽  
Guang Wei Zhu
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Internal Flow ◽  
Packed Bed ◽  
Liquid Distribution ◽  
Rotating Speed ◽  
Rotating Packed Bed ◽  
Flow Experiment ◽  
Mass Transfer Equipment ◽  
Counter Current

The rotating packed bed is a new and effective mass transfer equipment. However, because of the complexity fluid flow inside the RPB, the flow experiment are not easy to lead to the deeper understanding on the fluid dynamic in an RPB. To explore the internal flow field distribution of rotating packed bed , the internal flow field in counter-current double packing rotating packed bed was studied. At the same time, the flow field changes in different rotating speed was compared and the liquid distribution between the two layer of packing was performanced.

Selective Absorption of H2S from a Gas Mixture with CO2by AqueousN-Methyldiethanolamine in a Rotating Packed Bed

2010 ◽  
Vol 49 (13) ◽  
pp. 6196-6203 ◽  
Author(s):  
Zhi Qian ◽  
Lian-Bin Xu ◽  
Zhen-Hu Li ◽  
Hua Li ◽  
Kai Guo
Keyword(s):  
Packed Bed ◽  
Gas Mixture ◽  
Selective Absorption ◽  
Rotating Packed Bed

CO2 Capturing by MDEA-PZ-TETA in a Rotating Packed Bed

2014 ◽  
Vol 881-883 ◽  
pp. 645-648
Author(s):  
Mei Jin ◽  
Li Yan Zhou ◽  
Ping Lu ◽  
Jin Huang Wang ◽  
Guo Xian Yu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Packed Bed ◽  
Liquid Temperature ◽  
Gas Flow Rate ◽  
Rotating Speed ◽  
Rotating Packed Bed ◽  
Absorption Performance ◽  
Absorption Condition

The absorption performance of CO2 using MDEA-PZ-TETA ternary absorbent in a rotating packed bed was investigated. The effects of the concentration of the ternary absorbent, the absorbing liquid temperature, the rotating speed, the liquid flow rate and gas flow rate on the absorption performance of CO2 were discussed in detail. The experimental results showed that the optimum absorption condition was the absorbent concentration of 0.05 mol/L, the absorption temperature of 290 K, the rotating speed of 454 rpm and the ratio of gas to liquid of 1.2, which could provide a molar absorption saturated capacity of 1.3688 molCO2/molAm and a satisfying CO2 absorptivity of 93.18%.

scholarly journals Simultaneous removal efficiency of H2S and CO2 by high-gravity rotating packed bed: Experiments and simulation

2021 ◽  
Vol 19 (1) ◽  
pp. 288-298
Author(s):  
Lien Thi Tran ◽  
Tuan Minh Le ◽  
Tuan Minh Nguyen ◽  
Quoc Toan Tran ◽  
Xuan Duy Le ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Packed Bed ◽  
High Gravity ◽  
Gas Flow Rate ◽  
Solution Ph ◽  
Rotating Speed ◽  
Rotating Packed Bed

Abstract This study explores the possibility of applying high-gravity rotating packed bed (HGRPB) in removing H2S and CO2 from biogas. Ca(OH)2 aqueous solution was used as the absorbent in this study. Different experimental conditions including solution pH, rotating speed (R S) of HGRPB, gas flow rate (Q G), and liquid flow rate (Q L) were investigated with respect to the removal efficiency (E) of H2S and CO2. The experimental and simulated results show that the optimal removal efficiency of H2S and CO2 using HGRPB achieved nearly the same as 99.38 and 99.56% for removal efficiency of H2S and 77.28 and 77.86% for removal efficiency of CO2, respectively. Such efficiencies corresponded with the following optimal conditions: a solution pH of 12.26, HGRPB reactor with the rotating speed of 1,200 rpm, the gas flow rate of 2.46 (L/min), and the liquid flow rate of 0.134 (L/min).

scholarly journals Amorphous Nanoparticulate Formulation of Sirolimus and Its Tablets

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 155 ◽  
Author(s):  
Yudong Shen ◽  
Xingya Li ◽  
Yuan Le
Keyword(s):  
Methyl Cellulose ◽  
Packed Bed ◽  
In Vitro Dissolution ◽  
Structure Stability ◽  
Cellulose Content ◽  
Dissolution Profile ◽  
Rotating Speed ◽  
Enhanced Dissolution ◽  
Rotating Packed Bed

Nanocrystallization and amorphization have proven to be two effective strategies to improve the bioavailability of water-insoluble drugs. The purpose of our work was to develop a nano-formulated tablet of sirolimus (SRL) for enhanced dissolution. Amorphous SRL nanocomposites were prepared using anti-solvent precipitation via a high-gravity rotating packed bed. Various factors that affect particle size and size distribution, such as excipients, rotating speed, antisolvent/solvent flow rate, were investigated. Structure, stability and in vitro dissolution of the as-prepared SRL were evaluated. Furthermore, the nanoparticulated SRL tablet formula was screened to control drug release. Importantly, SRL tablets exhibit different dissolution profile by adjusting HPMC (hydroxypropyl methyl cellulose) content, which makes them more suitable for various formulation developments.

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