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Fundamentals and applications of an oscillatory flow meso-reactor

Mingzhi Zheng and Malcolm Mackley

Department of Chemical EngineeringUniversity of Cambridge

16th Nov., 2006

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Concept of meso-reactorD=50mm

d=5 mm

Scale- down

•Glass tube-easier to manufacture in small-scale compared with baffle-tube structure

•Easy to fit fit into laboratory fume cupboard

•Suitable for doing meso-scale pharmaceutical studies and small manufacturing of a few kilos of material

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Experimental PIV and Fluent®Simulated flow patterns

Influence of St

Experiment Simulation

Reo=312, St=0.4 Reo=312, St=0.2

Experiment Simulation

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RTD experiment set-up

fdf

Probe3

Probe1Dye Injection

Probe2

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Experimental E-curves

Small DispersionRen=9, Reo=156, St=0.8

Large DispersionRen=9,Reo=438,St=0.11

E(t)-curve

0.000

0.001

0.002

0.003

0.004

0 1000 2000 3000 4000 5000 6000

time (s)

E(t)

MS1S2

Probe 1

Probe 2Probe 3

E(t)-curve

0.000

0.001

0.001

0.002

0.002

0.003

0.003

0.004

0 1000 2000 3000 4000 5000 6000

time (s)

E(t)

MS1S2

Probe 1

Probe 2

Probe 3

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RTD Model fitting

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Liquid-liquid mixing

Particles in suspension

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Case study1: Homogeneous Liquid phase reaction

Crystal violet conc. VS. Time in stirred beaker

00.5

11.5

22.5

33.5

44.5

5

0 50 100 150 200 250 300

time(s)

c(m

g/L)

Crystal Violet conc. vs. Time in continuous meso-reactor

00.5

11.5

22.5

33.5

44.5

5

0 50 100 150 200 250 300

Mean Residence time, t (s)(positions along the reactor at steady state)

conc

entr

atio

n(m

g/m

l)

Conversion of crystal violet (CA/CA0) at the end of meso-reactorExperiment measurement

Tanks-in-series model + batch reaction kinetics prediction

0.335 0.337

Crystal violet fading in sodium hydroxide

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Case study 2: Liquid-liquid mixing reaction Biodiesel Production- Transesterification of triglycerides with alcohol

Biodiesel continuous operation in meso-reactorF=10 Hz, Xo=2.0 mm

0

0.5

1

1.5

2

2.5

3

3.5

0 5 10 15 20 25 30 35 40 45 50 55Mean Residence Time (min)

w/w

%

Mon %Di %Tri %EU-MonEU-Di&Tri

Biodiesel batch operation in meso-reactorF=10 Hz, Xo=2 mm

0

0.5

1

1.5

2

2.5

3

3.5

0 10 20 30 40 50Time(min)

w/w

%

Mon

Di

Tri

EU-Mon

EU-Di&Tri

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Case study 3: Precipitation reaction O

O OO O

O

O

O+ T B M E /5 0 C

F u ra n(6 8 .0 3 ) M a le ic a n h y d r id e

(9 8 .0 6 ) D ie ls A ld e r a d d u c t(1 6 6 )

D IE L S -A L D E R R E A C T IO N M O N IT O R E D B Y R E A C T IR

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Conclusion

• Fluid mechanics and Residence Time Distribution (RTD) in meso-reactor has been established.

• Proof of concept reaction has been successfully tested using continuous meso-reactor.

• The oscillatory flow meso-reactor is viable for ‘meso-scale’ continuous flow multiphase reactor.

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Acknowledgements

•Prof. Malcolm Mackley •Polymer Fluid Group•Department of Chemistry in Cambridge

•Ley Group•Cambridge Overseas Trust