Modelling ozonolysis in a multi-inlet flow reactor
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1) The document describes modeling the ozonolysis reaction of trans-2-butene in a multi-inlet flow reactor using a system of ODEs solved with kinetic simulation software. 2) Comparisons between the model and experimental data show the yield of vinoxy is overestimated in the model and vinoxy depletion by oxygen is underestimated. 3) More reaction channels and accurate rate constants are needed to better model the depletion of vinoxy and oxygen. The mechanism for trans-2-butene ozonolysis needs further refinement.
![We measure averages:
Nozone,average = [O3
0+(O3
1+(F1/F2)O3
0)+...+(O3
9+(F9/F10)O3
0)]/10
Nozone,segment = O3
s-1+(Fs-1/Fs)O3
0
Nspecies,segment = (Fs-1/Fs) Nspecies,s-1
Nspecies,average = [∑1
10 Nspecies,s]/10](https://image.slidesharecdn.com/gmf16-2-170130015200/85/Modelling-ozonolysis-in-a-multi-inlet-flow-reactor-8-320.jpg)
![0 1E16 2E16 3E16 4E16 5E16 6E16 7E16 8E16 9E16
0.20
0.40
0.60
0.80
1.00
1.20
[CH2
CHO]/[CH2
CHO]0
Oxygen (molecules/cc)
11/4/16
5/5/16
Vinoxy data (with new experiments from Friday)](https://image.slidesharecdn.com/gmf16-2-170130015200/85/Modelling-ozonolysis-in-a-multi-inlet-flow-reactor-9-320.jpg)
![0.00E+000 2.00E+015 4.00E+015 6.00E+015 8.00E+015 1.00E+016
0.0
0.2
0.4
0.6
0.8
1.0
Simulation
Exp 11/04/2016
Oxygen (molecule/cc)
[Vinoxy]/[Vinoxy]0
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
[Vinoxy]/[Vinoxy]0
Comparison experiment vs simulation](https://image.slidesharecdn.com/gmf16-2-170130015200/85/Modelling-ozonolysis-in-a-multi-inlet-flow-reactor-18-320.jpg)
Modelling ozonolysis in a multi-inlet flow reactor
- 1. Modelling ozonolysis in a multi-inlet flow reactor Mixtli Campos-Pineda Group Meeting 2 Fall 2016
- 2. 1 2 3 4 5 76 8 109P To pump 39.75” 22.75” Purge N2 Purge N2 Orange: Ozone inlet Green: Alkene inlet (+ Oxygen during oxygen experiments) Blue: plugged port (ultratorr+cap) Multi-inlet flow cell/CRDS cavity
- 3. Ozone flow manifold FMFM N2 in Ozone adsorbed in silica gel To flow cell Alkene + N2 + Scavenger flow manifold FM FM N2 in FM O2 in (oxygen experiments only) Alkene in To flow cell
- 4. Simulation of the reaction in a flow reactor. The system of ODEs is solved using an approximation method by the kinetic simulator KINTECUS.
- 5. Multi-Inlet Flow Cell (reaction perpendicular to beam) 1 2 3 4 5 76 8 109P Ozone in Alkene/Nitrogen /Scavenger in 1 2 3 4 5 76 8 109P To pump Pros: • Every segment is independent • No carryover reaction • Simple modelling Cons: • Turbulence
- 6. Multi-Inlet Flow Cell (reaction parallel to beam) 1 2 3 4 5 76 8 109P To pump Ozone + Alkene Ozone Pros: • Greatly reduced turbulence Cons: • Measurement is the average of segment concentrations • Initial conditions change for each segments
- 7. 1 2 3 4 5 76 8 109P To pump 39.75” 22.75” Purge N2 Purge N2 Orange: Ozone inlet Green: Alkene inlet (+ Oxygen during oxygen experiments) Blue: plugged port (ultratorr+cap) Multi-inlet flow cell/CRDS cavity Total flow changes due to ozone addition: • Ozone “spike” concentration changes • Species concentrations change
- 8. We measure averages: Nozone,average = [O3 0+(O3 1+(F1/F2)O3 0)+...+(O3 9+(F9/F10)O3 0)]/10 Nozone,segment = O3 s-1+(Fs-1/Fs)O3 0 Nspecies,segment = (Fs-1/Fs) Nspecies,s-1 Nspecies,average = [∑1 10 Nspecies,s]/10
- 9. 0 1E16 2E16 3E16 4E16 5E16 6E16 7E16 8E16 9E16 0.20 0.40 0.60 0.80 1.00 1.20 [CH2 CHO]/[CH2 CHO]0 Oxygen (molecules/cc) 11/4/16 5/5/16 Vinoxy data (with new experiments from Friday)
- 10. + O3 CH2CO CH3OH SOZ ++H2O P P P P P + + P + 2O2 P SOZ P OH OH + CO OH O2 H2OO3 OH wall decomp wall CH2OH CH3O H2O OH O2 + HO2 OHOH HO2 + O2 P 0.5 OH + P trans-2-butene ozonolysis mechanism used in KINTECUS (11/06/2016) 2 +H2O+H2C2 1.00 0.1 0.5 0.05 0.07 0.950.05 0.85 0.15 1.1E-12 2.6E-14 3.6E-15 1.7E-16 7.5E-13 1.9E-16 6.4E-11 1.6E-12 4E-18 370 s-1 1E-15 1E-12 6.12E-15 1.84E-14 3.67E-14 1E-11 9.1E-12 1E-11 10 s-1 10 s-1 1E-11 HCHO + OH HCO + H2O 7.5E-13
- 13. 0 2 4 6 8 10 0.00E+000 2.00E+013 4.00E+013 6.00E+013 8.00E+013 F A CH2CHO No oxygen
- 14. No oxygen 0 2 4 6 8 10 0.00E+000 2.00E+010 4.00E+010 6.00E+010 8.00E+010 1.00E+011 1.20E+011E A CH3CHOO
- 15. 8.45E15 molecule/cc oxygen 0 2 4 6 8 10 0.00E+000 1.00E+012 2.00E+012 F A CH2CHO
- 16. 8.45E15 molecule/cc oxygen 0 2 4 6 8 10 -2.00E+010 0.00E+000 2.00E+010 4.00E+010 6.00E+010 8.00E+010 1.00E+011 1.20E+011 1.40E+011 1.60E+011 1.80E+011 E A CH3CHOO
- 17. 8.45E15 molecule/cc oxygen 0 2 4 6 8 10 6.80E+015 7.00E+015 7.20E+015 7.40E+015 7.60E+015 7.80E+015 8.00E+015 8.20E+015 8.40E+015 8.60E+015 G A O2
- 18. 0.00E+000 2.00E+015 4.00E+015 6.00E+015 8.00E+015 1.00E+016 0.0 0.2 0.4 0.6 0.8 1.0 Simulation Exp 11/04/2016 Oxygen (molecule/cc) [Vinoxy]/[Vinoxy]0 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 [Vinoxy]/[Vinoxy]0 Comparison experiment vs simulation
- 19. • Vinoxy concentration from modelling much higher: Yield of vinoxy in model is overestimated Not enough vinoxy depletion channels, or rates underestimated • Vinoxy depletion by oxygen much higher: Vinoxy + Oxygen rates overestimated High vinoxy concentration in modelling driving reaction Not enough oxygen depletion channels, or rates underestimated
- 20. + O3 CH2CO CH3OH SOZ ++H2O P P P P P + + P + 2O2 P SOZ P OH OH + CO OH O2 H2OO3 OH wall decomp wall CH2OH CH3O H2O OH O2 + HO2 OHOH HO2 + O2 P 0.5 OH + P trans-2-butene ozonolysis mechanism used in KINTECUS (11/06/2016) 2 +H2O+H2C2 1.00 0.1 0.5 0.05 0.07 0.950.05 0.85 0.15 1.1E-12 2.6E-14 3.6E-15 1.7E-16 7.5E-13 1.9E-16 6.4E-11 1.6E-12 4E-18 370 s-1 1E-15 1E-12 6.12E-15 1.84E-14 3.67E-14 1E-11 9.1E-12 1E-11 10 s-1 10 s-1 1E-11 HCHO + OH HCO + H2O 7.5E-13
- 21. 0 2 4 6 8 10 0.00E+000 2.00E+010 4.00E+010 6.00E+010 8.00E+010 1.00E+011 1.20E+011 E A CH3CHOO Revisiting Criegee Intermediates
- 24. What about acetone oxide?
- 25. + O3 +
- 26. 0 2 4 6 8 10 -1.00E+011 0.00E+000 1.00E+011 2.00E+011 3.00E+011 4.00E+011 5.00E+011 6.00E+011 7.00E+011 G A CH3CO2CH3 Parallel
- 28. Summary Mechanism for t2b need more work! Time to revisit measurement of CIs