Summary of previous research and proposed work

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Summary of previous research and proposed work

• Matthew Lim
• (Cambridge PDRA)

CARMAC meeting 8-9th September 2004
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Academic background

• 2000 BEng (Hons.) in Chemical Engineering at
  Birmingham Undergraduate thesis Selective
  hydrogenation of crotonaldehyde Garner Prize
  (Top First)
• 2004 PhD in Chemical Engineering at Cambridge
• PhD thesis MRI of multiphase flow in
  packed bed reactors
• Roscoe Medal for excellence in
  Chemistry Rolls-Royce Prize in Engineering
  Science

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Previous results MRI of trickle flow
In past work we have shown the ability of MRI to
study holdup and wetting in the trickle flow
regime
These were quantified and tested against existing
models and showed good fits
These experiments were carried out at high
spatial resolution using spin echo imaging
techniques taking 20 minutes
The ultra-fast MRI techniques presented in this
work are at reduced resolution but at a much
higher temporal resolution of 50 Hz.
We have shown spatial gas-liquid distributions
and physical measurements of surface wetting
In past work we have shown the ability of MRI to
study holdup and wetting in the trickle flow
regime
These methods were used to study periodic
operation in trickle bed
We have shown spatial gas-liquid distributions
and physical measurements of surface wetting
Reference image
Trickle flow image
Binary gated image
Liquid hold-up
Solid-liquid interface
Surface wetting
These were quantified and tested against existing
models and showed good fits
These experiments were carried out at high
spatial resolution using spin echo imaging
techniques taking 20 minutes
Field of view 45 mm 45 mm. Resolution175 µm
175 µm. Acquisition time 20 minutes.
MRI visualisation of two-phase flow in
structured supports and trickle bed reactors
Gladden L.F., Lim, M.H.M, Sederman A.J., Mantle
M.D., Stitt E.H., Catalysis Today, 79(1-4),
203-210.
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Raw data
Multi-phase reactors
Trickle flow regime
Pulsing flow regime
Transition regime
Liquid flowrate 1.4 mm/s
Liquid flowrate 8.4 mm/s
Liquid flowrate 13.3 mm/s
Gas flowrate constant at 112 mm/s
Resolution 1.4 mm 2.8 mm Movies acquired at 50
f.p.s. All presented on the same intensity scale
http//www.cheng.cam.ac.uk/research/groups/mri/aic
hej.htm
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Proposed work long term goals

• AimTo successfully visualise in-situ reactions
  using MRI
• Methodology - Find a suitable candidate
  reaction which can be carried out at/near room
  temperature and pressure with favourable MRI
  properties - To further develop ultra fast
  Chemical Shift Imaging (CSI) techniques for use
  in candidate reactions - Application of
  multinuclear (e.g. 13C ) to image multiphase
  reacting systems

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Candidate reactions

• Oxidation of 1-Octanol

Octanol
Octanal
Octanoic acid

• Bourne reactions (neutralisation, hydrolysis)

k1
NaOH HCl
NaCl H2O
K1 1.3 ? 108 m3mol-1s-1 at 25oC
k2
NaOH CH2ClCO2C2H5
CH2ClCO2Na C2H5OH
RDS
Ethyl-chloroacetate
K2 2 ? 105 exp (-3.887 ? 104/RT) m3mol-1s-1
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Acknowledgements
Magnetic Resonance Research Group
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Octanoic acid
Octanal
Octanol
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