Effect of oscillation amplitude on velocity distributions in an oscillatory baffled column (OBC)

Hamzah, Ahmad Azahari; Hasan, Nurul; Takriff, Mohd Sobri; Kamarudin, Siti Kartom; Abdullah, J. B.; Tan, Isa M.; Sern, Wah Keng

doi:10.1016/j.cherd.2011.11.003

Cited by 17 publications

(16 citation statements)

References 16 publications

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“…As previously reported in the introduction of Part I, the majority of the studies in the literature describe the flow generated in OBRs in a qualitative manner using planar velocity fields and velocity profiles [2][3][4][5] or shear strain rate fields [6]. A significant number of studies have also evaluated the performance of OBRs in terms of axial dispersion via the analysis of residence time distributions [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamics and mixing in continuous oscillatory flow reactors—Part II: Characterisation methods

Mazubert

Fletcher

Poux

et al. 2016

Chemical Engineering and Processing: Process Intensification

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This work presents and exploits quantitative measures to better quantify the performance of oscillatory baffled reactors, being complementary to simple vector plots and shear strain rate fields. Novel performance criteria, including radial and axial fluid stretching and mixing, as well as the shear strain rate history of fluid elements have been developed and used to compare the performance of five different baffle designs, namely single orifice baffles, disc-and-donut baffles and three novel variations of helical blades. Analysis of residence time distributions has also been used to evaluate the geometries. The performance measures highlight that the disc-and-donut baffles can provide significant shear strain rates, which could be useful for multiphase applications, but also significant axial dispersion that is comparable with that for the single orifice baffles. The results also suggest that helical blade designs could be promising for decreasing axial dispersion, whilst maintaining significant levels of shear strain rate.

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Section: Introductionmentioning

confidence: 99%

Hydrodynamics and mixing in continuous oscillatory flow reactors—Part II: Characterisation methods

Mazubert

Fletcher

Poux

et al. 2016

Chemical Engineering and Processing: Process Intensification

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“…No other similar experimental data have been collected to confirm this result. Hamzah et al [13] report an increase of eddy lengths with the increase of the Strouhal number, but the increase of the Strouhal number ( Figure 5C) seems to decrease the mass fraction of esters in this case. The low value should be explained by poor liquid-liquid dispersion, visible to the naked eye, due to the decrease of the probability for the reactive mixture to meet baffles, spaced with 26 mm, with too low amplitude.…”

Section: Nitech ® Reactormentioning

confidence: 77%

Intensification of waste cooking oil transformation by transesterification and esterification reactions in oscillatory baffled and microstructured reactors for biodiesel production

Mazubert¹,

Aubin²,

Elgue³

et al. 2014

Green Processing and Synthesis

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The transformation of waste cooking oils for fatty acid methyl ester production is investigated in two intensified technologies: microstructured Corning ® and oscillatory baffled NiTech ® reactors, compared to a reference batch reactor to quantify the process intensification provided by each technology. Both reactors achieve high conversions in shorter times. For transesterification, 96 wt.% of esters are obtained in 1.4 min at 97°C in the Corning ® reactor and 92.1 wt.% of esters in 6 min at 44°C in the NiTech ® reactor, compared with 94.8 wt.% of esters in 10 min at 60°C in the batch reactor. For esterification, 92% conversion is obtained in 2.5 min in the Corning ® reactor at 75°C compared with 20-30 min in the batch reactor at 60°C, and at 40°C, 96.8% conversion is achieved in 13.3 min in the NiTech ® reactor, compared with 30 min in the batch reactor. The advantage of the Corning ® reactor is that it can operate at higher pressures (1-20 bar) and temperatures (100°C), thereby providing faster kinetics than the NiTech ® reactor. However, oils with a high free fatty acid level (73%) cause the Corning ® reactor channels to be blocked. A wider range of operating conditions could be obtained in NiTech ® with a pressure-resistant material.

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“…Early studies87,123,[138][139][140] revealed that the vortex mixing mechanism was responsible for the high mixing efficiency of the system and predictions of the onset of chaotic motions and concentration gradients were evaluated by incorporating transport such as heat and mass transfer and provided fluid-particle motion simulations 81,141,142. As mixing eddies have been shown to be the essential enhancer, large eddy simulations (LESs)67,143,144 have been particularly suited for studying flow in an OFR and the effects of f and x 0 have been investigated.The flow characteristics of oscillatory flow are dominated by the axial velocity components (seeFigure 8) but with numerical studies there is now good understanding of the nature of the mixing [145][146][147][148][149]. At Re 0 = 100 -300, the OFR exhibits good plug-flow characteristics where the vortices are axi-symmetrically generated within each baffled cavity (referred to as plug-flow…”

mentioning

confidence: 97%

Oscillatory Flow Reactors (OFRs) for Continuous Manufacturing and Crystallization

McGlone

Briggs

Clark³

et al. 2015

Org. Process Res. Dev.

188

198

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Continuous crystallization is an attractive approach for the delivery of consistent particles with specified critical quality attributes (CQAs) attracting increased interest for the manufacture of high value materials including fine chemicals and pharmaceuticals. Oscillatory flow reactors (OFRs) offer a suitable platform to deliver consistent operating conditions under plug-flow operation whilst maintaining a controlled steady state. This review provides a brief overview of OFR technology before outlining the operating principles and summarizing applications, emphasizing the use for controlled continuous crystallization. Whilst significant progress has been made to date, areas for further development are highlighted that will enhance the range of applications and ease of implementation of OFR technology. These depend on specific application but include scale down, materials of construction suitable for chemical compatibility and encrustation mitigation and the enhancement of robust operation via automation, process analytical technology (PAT) and real-time feedback control.

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Effect of oscillation amplitude on velocity distributions in an oscillatory baffled column (OBC)

Cited by 17 publications

References 16 publications

Hydrodynamics and mixing in continuous oscillatory flow reactors—Part II: Characterisation methods

Hydrodynamics and mixing in continuous oscillatory flow reactors—Part II: Characterisation methods

Intensification of waste cooking oil transformation by transesterification and esterification reactions in oscillatory baffled and microstructured reactors for biodiesel production

Oscillatory Flow Reactors (OFRs) for Continuous Manufacturing and Crystallization

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