Reaction calorimetric and spectroscopic studies of an ionic liquid synthesis [Elektronische Ressource] / vorgelegt von Clemens B. Minnich

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2009
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 19 Mo

Extrait

Reaction calorimetric
and spectroscopic studies
of an Ionic Liquid synthesis
Von der Fakult at fur Mathematik, Informatik und Naturwissenschaften
der RWTH Aachen University zur Erlangung des akademischen Grades
eines Doktors der Ingenieurswissenschaften genehmigte Dissertation
vorgelegt von
Diplom-Chemiker
Clemens B. Minnich
aus
Hildesheim
Berichter: Universit atsprofessor Dr. rer. nat. Marcel A. Liauw
Universit Dr.-Ing. Wolfgang Marquardt
Tag der mundlic hen Prufung: 8. Mai 2009
Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfugbar.Contents
1 Outline 3
2 Approaches towards process design 7
2.1 General design aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Batch vs. continuous ow operation . . . . . . . . . . . . . . . . . . . . . 9
2.3 (Micro-)structures - to which degree? . . . . . . . . . . . . . . . . . . . . 9
2.4 Prominent applications of structured reaction devices . . . . . . . . . . . 12
2.5 Process example: Ionic Liquid synthesis . . . . . . . . . . . . . . . . . . . 13
3 Reaction calorimetry 17
3.1 Energy balance of an arbitrary reactor . . . . . . . . . . . . . . . . . . . 17
3.2 Meaning and development of reaction calorimetry . . . . . . . . . . . . . 19
3.3 Heat ows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.4 Modes of calorimeter operation . . . . . . . . . . . . . . . . . . . . . . . 23
3.5 Principles of calorimeter construction . . . . . . . . . . . . . . . . . . . . 24
3.5.1 Heat ow calorimeters . . . . . . . . . . . . . . . . . . . . . . . . 24
3.5.2 Heat balance . . . . . . . . . . . . . . . . . . . . . . 26
3.5.3 Power compensation calorimeters . . . . . . . . . . . . . . . . . . 26
3.5.4 Peltier-based calorimeters . . . . . . . . . . . . . . . . . . . . . . 27
3.5.5 Comparison of the calorimetric principles . . . . . . . . . . . . . . 28
3.6 Evaluation of calorimetric data . . . . . . . . . . . . . . . . . . . . . . . 29
3.7 Reaction calorimetry for process monitoring and control . . . . . . . . . . 31
4 Mid-infrared spectroscopy 33
4.1 Motivation: Process Analytical Technology . . . . . . . . . . . . . . . . . 33
4.1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.1.2 Classi cation of sensors . . . . . . . . . . . . . . . . . . . . . . . . 34
4.2 Spectroscopic methods for process monitoring . . . . . . . . . . . . . . . 35
4.3 Attenuated Total Re ectance . . . . . . . . . . . . . . . . . . . . . . . . 36
4.3.1 Re ection at an optical interface . . . . . . . . . . . . . . . . . . 36
iContents
4.3.2 The internal re ection element . . . . . . . . . . . . . . . . . . . . 37
4.4 Fibre optical ATR sensors . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.4.1 Fibres for mid-infrared spectroscopy . . . . . . . . . . . . . . . . . 39
4.4.2 The bre optical probe developed by ifs-aachen . . . . . . . . . . 39
5 Chemometrics 43
5.1 Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.2 Univariate methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.3 Multivariate methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.3.1 Data basis and model parameters . . . . . . . . . . . . . . . . . . 46
5.3.2 Principal Component Analysis and Regression . . . . . . . . . . . 46
5.3.3 Partial Least Squares . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.4 Hard modelling approaches . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.4.1 Indirect Hard Modelling: Concept . . . . . . . . . . . . . . . . . . 51
5.4.2 Indirect Hard Mo Procedure . . . . . . . . . . . . . . . . . 52
5.4.3 Identi cation of unknown pure compound spectra . . . . . . . . . 54
6 Reaction calorimetric batch experiments 57
6.1 Initial situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6.2 Evaluation of the heat ow pro les . . . . . . . . . . . . . . . . . . . . . 60
6.2.1 Reference semi-batch experiments . . . . . . . . . . . . . . . . . . 63
6.2.2 Variations in semi-batch experiments . . . . . . . . . . . . . . . . 67
6.2.3 Fed-batch experiments . . . . . . . . . . . . . . . . . . . . . . . . 70
6.2.4 Conclusions from thermodynamics . . . . . . . . . . . . . . . . . 71
6.3 Insights into kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6.3.1 Diluted system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6.3.2 Solvent-free system . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.3.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
7 \Tapless tap reactor" 85
7.1 Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.2 Preliminary stages of continuous ow setups . . . . . . . . . . . . . . . . 86
7.3 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
7.3.1 Substrate preparation and uid reservoirs . . . . . . . . . . . . . 88
7.3.2 Dosing pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
7.3.3 Thermostated mixer box . . . . . . . . . . . . . . . . . . . . . . . 90
7.3.4 Capillary modules for variable residence times . . . . . . . . . . . 91
7.4 Sensors, software and control system structure . . . . . . . . . . . . . . . 92
iiContents
7.4.1 The LabVIEW substructure . . . . . . . . . . . . . . . . . . . . . 94
7.4.2 Flow cells for concentration measurements . . . . . . . . . . . . . 94
7.4.3 Performance of the structured IR ow cells . . . . . . . . . . . . . 97
7.5 Residence time distribution . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.5.1 Ideal vs. real reactors . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.5.2 Selection and validation of the marker system . . . . . . . . . . . 103
7.6 Experimental determination of residence time behaviour . . . . . . . . . 105
7.7 Pressure drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
8 Continuous [EMIM]EtSO synthesis 1114
8.1 Implementation of the analytical methods for process monitoring . . . . . 111
8.1.1 PLS-based calibration model . . . . . . . . . . . . . . . . . . . . . 112
8.1.2 Calibration of ternary mixtures with IHM . . . . . . . . . . . . . 116
8.1.3 Validation of IR measurements with NMR spectroscopy . . . . . . 123
8.2 Experiments and observations . . . . . . . . . . . . . . . . . . . . . . . . 124
8.2.1 Experiments in the preliminary setup . . . . . . . . . . . . . . . . 125
8.2.2 Experiments in the \tapless tap reactor" . . . . . . . . . . . . . . 128
9 Conclusion 135
References 142
A Methods 143
A.1 Expression of kinetic models with mole fractions . . . . . . . . . . . . . . 143
A.2 Preparation of chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
A.3 Analytical methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
A.3.1 NMR analysis of samples from Ionic Liquid synthesis . . . . . . . 145
A.3.2 Quality control of Ionic Liquid samples . . . . . . . . . . . . . . . 145
A.3.3 FTIR measurements . . . . . . . . . . . . . . . . . . . . . . . . . 146
A.4 Calculation of residence time behaviour . . . . . . . . . . . . . . . . . . . 148
B Details from reaction calorimetry 149
B.1 General remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
B.1.1 Experiments in the RC 1 . . . . . . . . . . . . . . . . . . . . . . 149
B.1.2 Expts in the LabKit rcb . . . . . . . . . . . . . . . . . . . . 150
B.1.3 Experiments in the CPA 202 . . . . . . . . . . . . . . . . . . . . 150
B.2 Data from semi-batch experiments . . . . . . . . . . . . . . . . . . . . . 150
B.2.1 Proposed reaction network for the experimental design . . . . . . 160
iiiContents
B.2.2 Experimental design for validation of the postulated reaction net-
work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
C Details from spectral modelling 167
C.1 Fit results of calibration spectra . . . . . . . . . . . . . . . . . . . . . . . 171
C.2 Cross-validations for calibrations . . . . . . . . . . . . . . . . . . . . . . 175
D Hardware speci cations 177
D.1 Dosing pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
D.2 Mixer box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
D.3 Capillary modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
D.4 Stainless steel ow cells for bre probes . . . . . . . . . . . . . . . . . . . 179
ivList of Figures
1.1 Elements of process design. . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Synthesis of [EMIM]EtSO . . . . . . . . . . . . . . . . . . . . . . . . . . 144
3.1 Heat ows in an isothermal batch reactor. . . . . . . . . . . . . . . . . . 23
4.1 Fibre probe developed by ifs-aachen. . . . . . . . . . . . . . . . . . . . . 40
4.2 Single channel spectra for di erent bre lengths. . . . . . . . . . . . . . . 41
5.1 Schematic comparison between PCA/PCR and PLS calibrations. . . . . . 48
6.1 Synthesis of [EMIM]EtSO . . . . . . . . . . . . . . . . . . . . . . . . . . 584
6.2 Heat ow pro le from MIM injections into DES. . . . . . . . . . . . . . . 64
6.3 O set correction of the heat ow signal. . . . . . . . . . . . . . . . . . . 65
6.4 Heat ow pro le from DES injections into MIM. . . . . . . . . . . . . . . 66
6.5 Heat ow pro le and integrated heat ow from EtBr injections into MIM. 68