Influence of Sparger Type on Mass Transfer in a Pilot-Scale Internal Loop Airlift Reactor

Wang, Zongliang; Guo, Hu; Zhou, Taofa; Cheng, Zhenmin; Huang, Zibin

doi:10.3390/pr10020429

Cited by 7 publications

(3 citation statements)

References 34 publications

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“…Naidoo et al and Wang et al found that in the pilot-scale external loop ALRs, the bubble size decreased as the diameter of the pores of the perforated plate decreased. [48,49] Additionally, with smaller bubbles, the gas holdup increased and mass transfer performance improved. Ham et al found that fine sand and coarse sand diffusers can promote the mass transfer in an ALR owing to the small bubbles having long residence time.…”

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confidence: 99%

Gas holdup, bubble size distribution, and mass transfer in an airlift reactor with ceramic membrane and perforated plate distributor

et al. 2023

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The airlift reactor is one of the most commonly used gas–liquid two‐phase reactors in chemical and biological processes. The objective of this study is to generate different‐sized bubbles in an internal loop airlift reactor and characterize the behaviours of the bubbly flows. The bubble size, gas holdup, liquid circulation velocity, and the volumetric mass transfer coefficient of gas–liquid two‐phase co‐current flow in an internal loop airlift reactor equipped with a ceramic membrane module (CMM) and a perforated‐plate distributor (PPD) are measured. Experimental results show that CMM can generate small bubbles with Sauter mean diameter d32 less than 2.5 mm. As the liquid inlet velocity increases, the bubble size decreases and the gas holdup increases. In contrast, PPD can generate large bubbles with 4 mm < d32 < 10 mm. The bubble size and liquid circulation velocity increase as the superficial gas velocity increases. Multiscale bubbles with 0.5 mm < d32 < 10 mm can be generated by the CMM and PPD together. The volumetric mass transfer coefficient kLa of the multiscale bubbles is 0.033–0.062 s−1, while that of small bubbles is 0.011–0.057 s−1. Under the same flow rate of oxygen, the kLa of the multiscale bubbles increases by up to 160% in comparison to that of the small bubbles. Finally, empirical correlations for kLa are obtained.

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confidence: 99%

Gas holdup, bubble size distribution, and mass transfer in an airlift reactor with ceramic membrane and perforated plate distributor

et al. 2023

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“…The radial positions were at the center and sidewall inside the reactor. The detailed experimental steps can be obtained from our previous research work [31]. Since temperature also has a significant impact on k L a, when the ambient temperature changes, correction can be performed using the following equation [32][33][34]:…”

Section: Experimental Workmentioning

confidence: 99%

The Influence of Draft Tubes on the Mass Transfer and Mixing Performance of a Pilot-Scale Internal-Loop Airlift Reactor

Wang,

Cheng,

Yuan

et al. 2023

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The hydrodynamic characteristics, mass transfer, and mixing performance of three different reactors, a bubble column reactor (BCR), a single-stage internal-loop airlift reactor (SSALR), and a four-stage internal-loop airlift reactor (FSALR), were investigated systematically through cold model experiments to explore the influence of draft tube configurations on the pilot-scale internal-loop airlift reactor (ILAR). The findings indicated that the BCR yielded a higher gas holdup and mass transfer coefficient due to its longer bubble residence time. Segmenting the draft tube improved the gas holdup in both the riser and downcomer, and the overall gas holdup in the downcomer increased by 9%. Compared with the SSALR, the mass transfer coefficient of the FSALR in the riser and downcomer increased by 10.2% and 9.3% on average, respectively. In addition, a higher liquid circulating velocity was obtained with the ILARs due to a higher gas holdup difference between the riser and the downcomer. Specifically, the liquid circulating velocity of the FSALR was 134.1% higher than that of the BCR and 15.8% higher than that of the SSALR. The mixing time of the ILARs was reduced due to more intense overall circulation. The mixing effect of the FSALR was the best. The mixing time was reduced by 70.2% and 51.3% compared with the BCR and SSALR for UG ranging from 4.0 cm/s to 9.1 cm/s, respectively. Empirical correlations were proposed for the gas holdup, liquid circulating velocity, mass transfer coefficient, and mixing time on the superficial gas velocity, and agreement with experimental data was satisfactory.

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“…The two-stage had better performance improvement. Then, Wang et al [18] studied the hydrodynamic characteristics, mass transfer, and mixing performance of three different reactors, a bubble column reactor, a single-stage internal loop airlift reactor, and a four-stage internal loop airlift reactor. The transfer performance of the four-stage is better than the other two.…”

Section: Introductionmentioning

confidence: 99%

The Study of Fluid Dynamics Simulation of the Internal Flow Field in a Novel Airlift Oscillation Loop Bioreactor

Liu,

Sun,

Liu

2023

Processes

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The three-dimensional flow and mass transfer conditions in 5 L and 40 L airlift oscillation loop reactors were studied and compared with existing two-dimensional simulation and experimental data to verify the accuracy of the method. Then, the fluid dynamics behavior of the 2500 L reactor was simulated via supercomputing and provided guidance for production data. The results indicate that the application of oscillation operation in the 40 L multi-guide tube reactor can effectively improve the gas holdup and mass transfer coefficient in the reactor, with a maximum increase of 38% and 29%. For the 2500 L multi guide tube reactor, oscillation operation oscillation operation can significantly improve gas holdup and mass transfer coefficient increase gas holdup by 46% under 0.5 vvm operating conditions; the mass transfer coefficient increased by 54%. Therefore, oscillation operation can greatly improve the mass transfer coefficient for actual production reactors. After digging a hole in the middle sleeve, the circulating liquid speed has no effect. Although the gas holdup and mass transfer coefficient decreased by 1.3%, the gas holdup inside the entire reactor was more uniform, effectively reducing the average bubble aggregation.

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Influence of Sparger Type on Mass Transfer in a Pilot-Scale Internal Loop Airlift Reactor

Cited by 7 publications

References 34 publications

Gas holdup, bubble size distribution, and mass transfer in an airlift reactor with ceramic membrane and perforated plate distributor

Gas holdup, bubble size distribution, and mass transfer in an airlift reactor with ceramic membrane and perforated plate distributor

The Influence of Draft Tubes on the Mass Transfer and Mixing Performance of a Pilot-Scale Internal-Loop Airlift Reactor

The Study of Fluid Dynamics Simulation of the Internal Flow Field in a Novel Airlift Oscillation Loop Bioreactor

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