Evelien Van de Steene
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Laboratory for Chemical Technology, Ghent University http://www.lct.UGent.be Experimental and kinetic study of the Transesterification of Ethyl acetate and Methanol over Gel and Macroporous acidic ion – exchange resins Evelien Van de Steene 1
description
Experimental and kinetic study of the Transesterification of Ethyl acetate and Methanol over Gel and Macroporous acidic ion – exchange resins. Evelien Van de Steene. Transesterification. Transesterification: Biodiesel production. Transesterification: Model reaction. - PowerPoint PPT Presentation
Transcript of Evelien Van de Steene
Laboratory for Chemical Technology, Ghent University
http://www.lct.UGent.be
Experimental and kinetic study of the Transesterification of Ethyl acetate and
Methanol over Gel and Macroporous acidic ion – exchange resins
Evelien Van de Steene
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Transesterification
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Transesterification: Biodiesel production
Transesterification: Model reaction
PhD symposium, Ghent, 5th December 2012
Ion exchange resin as catalyst
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EcofriendlyNoncorrosiveReusable
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Gel-type resins (K1221)
Macroporous resins (K2629, K2640, Amberlyst 15)
No permanent pore structureMicroporesSwelling !
Permanent pore structureMacro- & Micropores
4 – 10 % DVB 10 – 20 % DVB
PhD symposium, Ghent, 5th December 2012
Ion exchange resin swells !
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25 mL
MeO
H
25 mL
MeO
H
10 mL dry K2649
16 mLwet K2649
25 mL MeOH
18 % DVB
10 mL dry K1221
> 25 mLwet K1221
25 mL MeOH
4 % DVB
Higher DVB content => less swelling
PhD symposium, Ghent, 5th December 2012
The swelling influences the reaction rate
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18 %
20 %
4 %
total active sites = for all resins% DVB determines the conversion
PhD symposium, Ghent, 5th December 2012
Temperature : 333 KPressure : 0.1 MpaMeOH:EtOAc molar ratio: 10:1Mass of catalyst: 0.5 kg
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Eley-Rideal reaction mechanism
MeOHEtOAc
EtOHMeOAc
* * **
* * * *
** * *
* * ** * * **
Reaction Mechanism & kinetic model
Total swelling =>
MeOAc* + MeOH MeOH* + MeOAc
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EtOH MeOAcSR EtOAc EtOAc
eq MeOH
EtOAc EtOAc MeOAc MeOAc
MeOH MeOH
a ak K aK a
r K a K aa a
Resulting kinetic model
PhD symposium, Ghent, 5th December 2012
MeOH* + EtOAc EtOAc* + MeOH* + MeOH MeOH*
MeOH + EtOAc* EtOH + MeOAc*
Active (acid) site
• Good agreement: model calculations vs. experimental data
• EA = 49 kJ mol-1 irrespective the catalyst used
• kSR (gel) = 3 à 4-fold kSR (macroporous)
• kSR ~ available active sites ~ swelling
• => affinity of ester is the same for all resin7
Kinetic modeling resultsResin Kinetic parameters
Ion-exchange equilibrium coefficient
Statistical evaluation
(10-6 m3 kgcat-1 mol-1 s-1) (kJ mol-1)
Total number of experimental
data RSSQ F
K1221 52.7 ± 0.3 48.7 ± 0.9 1.15 ± 0.14 4.87 ± 0.38 1282 24 71 000K2640 14.5 ± 4.1 42.9 ± 5.6 1.86 ± 0.67 6.26 ± 1.90 233 2 18 000K2629 9.2 ± 1.0 49.7 ± 2.0 2.54 ± 0.35 9.04 ± 2.03 702 2 125 000Amberlyst 15 10.3 ± 7.5 52.3 ± 6.6 1.36 ± 0.99 0.90 ± 6.04 129 6 35 000
TrefSRk AE EtOAcK MeOAcK
3.3 4.2MeOAc
EtOAc
KK
PhD symposium, Ghent, 5th December 2012
Thank you for your kind attention
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PhD symposium, Ghent, 5th December 2012
