Optimization of the dehydration of glycerol to acrolein and a scale up in a pilot plant [Elektronische Ressource] / vorgelegt von Sergio Sabater Prieto

Sergio Sabater

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2007
• Nombre de lectures: 22
• Langue: English
• Poids de l'ouvrage: 4 Mo

Extrait

Optimization of the
Dehydration of Glycerol to
Acrolein and a Scale up in a
Pilot Plant





Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der
Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des
akademischen Grades eines Doktors der Ingenieurwissenschaften genehmigte
Dissertation


vorgelegt von

Diplom – Ingenieur Sergio Sabater Prieto


aus Valencia (Spanien)



Berichter: Universitätsprofessor Dr.rer.nat. W.F. Hölderich
Universitätsprofessor Dr.-Ing. T. Melin

Tag der mündlichen Prüfung: 19.10.2007

Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar.








































This work was carried out from 2005 to August 2007 at the chair for Chemical
Technology and Heterogeneous Catalysis at the University of Technology, RWTH Aachen.

I would like to thank Prof. Dr. rer. Nat. W. F. Hölderich for providing the
interesting topic, and for his advice and inspiration.

This work was carried out as the engineering part of the project. I am grateful to
the company Arkema for its financial support and to its employees for stimulating and
helpful discussions, in special to Dr. Dubois, Dr. Tessier, Dr. Devaux, and Miss Serreau.

Special thanks to Dipl. Chem. Arda Ülgen, co-worker in the chemical part of the
project for his help, support and advices.

I would like to thank all the technicians for their help and advices in the analysis
part of the project.












































































To my family
























I
Contents

1 Chapter 1. Introduction ................................................................................ 1
1.1 Introduction ............................................................................................ 1
1.1.1 General information about glycerol.......................................................... 2
1.1.1.1 Environmental attractiveness of glycerol versus propylene .................. 3
1.1.1.2 Economical attractiveness of glycerol versus propylene....................... 3
1.1.2 General information about acrolein.......................................................... 4
1.1.3 The dehydration of glycerol.................................................................... 5
1.1.4 Reaction mechanism ............................................................................. 6
1.2 Previous experiments ............................................................................... 6
1.2.1 Experimental setup ............................................................................... 7
1.2.2 Experimental session............................................................................. 7
1.2.3 Description of the catalyst WO /ZrO ....................................................... 9 3 2
2 Chapter 2. General Calculations ...................................................................11
2.1 Thermodynamics.....................................................................................11
2.2 Phase Diagram Water - Glycerol................................................................15
2.2.1 Calculation of the vapor pressure...........................................................15
2.2.2 Determination of the P-x-y and T-x-y phase diagrams..............................16
2.3 Calculation of the Explosive Ranges...........................................................21
2.3.1 Determination of the oxygen percentage in the presence of glycerol ..........21
2.3.2 Determination of the oxygen percentage in presence of acrolein................23
2.4 Calculation Methods for Selectivity and Conversion......................................26
2.4.1 Calibration Curves................................................................................26
2.4.2 Determination of mass balances ............................................................29
2.4.2.1 Catalyst mass balance .................................................................. 29
2.4.2.2 Liquid mass balance ..................................................................... 29
2.4.3 Determination of the conversion and the selectivity..................................29
2.4.3.1 Determination of conversion.......................................................... 29
2.4.3.2 Determination of selectivity........................................................... 30
2.5 Kinetic ...................................................................................................31
2.5.1 Theoretical background ........................................................................31
2.5.2 Experimentation ..................................................................................33
2.5.2.1 Determination of the reaction rate equation..................................... 34
2.5.2.2 Determination of the kinetic constant k and the apparent order n....... 36
2.5.2.3 Determination of the Activation Energy E ....................................... 39 a
3 Chapter 3. Laboratory Plant .........................................................................41 II
3.1 Description of the process steps................................................................41
3.2 Determination of the limitation step of the reaction .....................................43
3.2.1 External Mass Transfer .........................................................................43
3.2.2 Internal Mass Transfer..........................................................................45
3.3 Design of Experiments using WO /ZrO catalyst ..........................................52 3 2
3.3.1 Producing the data base .......................................................................52
3.3.2 Design Expert. Experiments ..................................................................54
3.3.3 Unknown Products ...............................................................................72
3.3.4 Analysis of the data..............................................................................74
3.3.5 Conclusions of the analysis ...................................................................82
3.3.5.1 The glycerol conversion................................................................. 82
3.3.5.2 The selectivity of acrolein.............................................................. 82
3.3.5.3 The selectivity of acetaldehyde ...................................................... 82
3.3.5.4 The selectivity of propanal............................................................. 82
3.3.5.5 The selectivity of acetone.............................................................. 82
3.3.5.6 The selectivity of HPO................................................................... 83
3.3.5.7 The selectivity of phenol ............................................................... 83
3.3.6 Approaching for finding an optimum working point...................................83
3.3.7 Optimization........................................................................................84
3.3.8 Discussion about the obtained solution ...................................................91
3.3.8.1 Effect of the temperature .............................................................. 91
3.3.8.2 Effect of the glycerol solution flow .................................................. 91
3.3.8.3 Effect of the glycerol concentration................................................. 92
3.3.8.4 Effect of the oxygen flow............................................................... 92
3.3.9 Prediction points..................................................................................93
4 Chapter 4. Pilot Plant ...................................................................................97
4.1 Description of the process steps................................................................97
4.2 Design of the Reactor ..............................................................................99
4.3 Experiments carried out in t