Single-drop based modelling of solvent extraction in high-viscosity systems [Elektronische Ressource] / Donni Adinata

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Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2011
• Nombre de lectures: 12
• Langue: English

Extrait

Single-Drop Based Modelling of
Solvent Extraction in High-Viscosity Systems





Von der Fakultät für Maschinenwesen der Rheinisch-Westfälischen
Technischen Hochschule Aachen zur Erlangung des akademischen
Grades eines Doktors der Ingenieurwissenschaften genehmigte
Dissertation




vorgelegt von

Donni Adinata





Berichter: Univ.-Prof. Dr.-Ing. Andreas Pfennig
Univ.-Prof. Dr.rer.nat. Marcel Liauw
Tag der mündlichen Prüfung: 19.07.2011



Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar























Gedruckt mit Unterstützung des Deutschen Akademischen Austauschdienstes

ii
Preface and Dedications


This thesis is the final work of my PhD study at the Institute of Thermal Process
Engineering at the RWTH Aachen University.

First of all, I wish express my sincere gratitude and respect to my supervisor
Professor Dr.-Ing Andreas Pfennig for his creative ideas, patience, advice, and help
that give significant value for this dissertation. Secondly, I would like to express my
appreciation to Professor Dr. Marcel Liauw for being a member of the committee.
Professor Dr.-Ing. Burkhard Corves I thank for being the chairman of the PhD
committee.

I would also like to express my deepest appreciation to all my colleagues at the
Institute of Thermal Process Engineering, RWTH Aachen University. Thank you all
for the pleasant working atmosphere.

Last but not least, this thesis is dedicated to my beloved mother, father, sisters,
brother, and closest friends. Their love, understanding, patience and support have
given me the strength and spirit to the completion of this thesis.



Aachen, July 2011


Donni Adinata






iiiTable of Contents


1. Introduction……………………………………………………………………….. 1
1.1 Motivation…………………………………………………………………….. 1
1.2 Research Objectives………………………………………………………… 2

2. Literature Review…………………………………………………………………. 3

Sedimentation behaviour of drops……………………………………………. 5 3.
3.1 Introduction…………………………………………………………………… 5
3.2 Drop Behaviour………………………………………………………………. 6
3.3 Single-Drop Sedimentation Experiments …………................................. 14
3.3.1 Material System……………………………………………………… 14 3.3.2 Experimental Set-up………………………………………………… 17
3.3.3 Procedure……………………………………………. 18
3.4 Experimental Results and Model Evaluation……………………………… 20
3.4.1 Influence of Viscosity of Continuous Phase on Sedimentation
Velocity of Drops…………………………………………………….. 20
3.4.2 Influence of Viscosity of Disperse Phas 21
3.4.3 Influence of Mass Transfer on Sedimentation Velocity of
Drops…………………………………………………………………. 22
3.4.4 Modeling of Sedimentation Velocity of Drops in High Viscosity
System ………………………………………………….................... 23
3.4.5 General Parameter of Sedimentation Velocity of Drops in High-
Viscosity Systems……………………………………………………. 26
3.5 Conclusions…………………………………………………………………… 34

4. Mass Transfer of Single Drop…………………………………………………... 37
4.1 Introduction……………………………………………………………………. 37
4.2 Theory and Mathematical Model of Mass Transfer in Single Drop……... 38
4.2.1 Mass-Transfer Rate in Liquid-Liquid System…………………...... 38
4.2.2 Mass Transfer Coefficient in Continuous Phase…………………. 39
iv 4.2.3 Mass Transfer Coefficient in Single Drop…………………………. 40
4.3 Mass Transfer of Single Drop Experiments……………………………….. 43
4.3.1 Experimental Set-up…………………………………………………. 44 4.3.2 Procedure…………………………………………….. 45
4.3.3 Analytical Methods…………………………………………………... 47
4.4 Experimental Results and Discussions……………………………………. 47
4.4.1 Influence of the Viscosity of Continuous Phase on Mass
Transfer of Single Drop……………………………………………… 48
4.4.2 Influence of the Viscosity of Disperse Phase on Mass Transfer
of Single Drop………………………………………………………… 49
4.4.3 51 The Instability Constant, C ……………………………………….. IP
4.5 Conclusions…………………………………………………………………… 55

5. Extraction Column Behaviours………………………………………………… 56
5.1 Introduction……………………………………………………………………. 56
5.2 Concept and Principle of ReDrop Algorithm…………………………........ 57
5.3 Extraction Column Behaviour: Experiments and Simulation…………….. 59
5.3.1 Pilot-plant Experiments …………………………………………….. 59
5.3.1.1 Materials System………………………………………… 60
5.3.1.2 Experimental Set-up…………………………………….. 60
5.3.1.3 Experimental Procedure………………………………… 62 5.3.1.4 Analysis Methods………………………………………… 63
5.3.2 Simulation of Extraction-Column Behaviour by Using ReDrop for
Viscous System…………………………………………………........ 64
5.4 Experimental Results and Comparison with ReDrop Simulation……….. 67
5.4.1 Drop Size……………………………………………………………… 69 5.4.2 Hold-up……………………………………………..…………………. 72
5.4.3 Mass Transfer………………………………………………………… 74
5.4.4 Extraction in high-viscosity systems …..……………..................... 76
5.5 Conclusions …………………………….…………………………………….. 77

6. Summary……………………………………………………………………………. 79

Appendix………………………………………………………………………………… 81
vNomenclature…………………………………………………………………………… 97
References………………………………………………………………………………. 101


















viList of Figures

3.1 Drop behaviour as a function of drop diameter ………………………... 6
3.2 Sedimentation velocities of drops (material system: water (c)
+ tridecanol (d))…………………………………………………………..... 7
3.3 Force-balance a drop in the vertical direction………………………….. 9
3.4 Influence of mass transfer in a physical extraction system …………... 14
3.5 Sketch of the sedimentation cell…………………………………………. 17
3.6 Influence of viscosity of continuous phase on sedimentation velocity
of drops, system with variation of the viscosity of the continuous
phase ……………………………………………………………………….. 21
3.7 Influence of viscosity of disperse phase on sedimentation velocity of
drops, system with variation of the viscosity of the continuous
phase……..…………………………………………………………………. 22
3.8 Influence of mass transfer in systems with constant density of the
continuous phase…………………………………………………………... 23
3.9 The fitting results of Henschke’s model (2003) with the experimental
results …………………………………………………………..….……….. 24
3.10 Calculated values of a and a as function of d ……………………. 2715 16 SW
3.11 Minimum mean deviation between experimental and model results
as function of a …………………………………………………………… 2815
3.12 Mean deviation between experimental and model result as function
of d ………………………………………………………………………... 30SW
3.13 Minimum absolute deviation between experimental and model
results as function of d in the toluene with paraffin system..……….. 31SW
3.14 Minimum absolute deviation between odel d for the toluene system………………………. 31SW
3.15 Minimum absolute deviation between experimental and model
results as function of a ...………………………………………………… 3316
3.16 the fitting results of Henschke’s model (2003) with experimental
results of sedimentation velocity by using the generalized values of
d , a and a for toluene and toluene with paraffin ………………… 34SW 15 16
4.1 Concentration profiles at the interphase during mass-transfer for
single droplets……………………………………………………………… 39
vii4.2 Laboratory scale mass-transfer cell……………………………………… 44
4.3 Flow diagram of mass-transfer cell in laboratory scale………………... 46
+4.4 48The dimensionless concentration y for low viscosity system………..
4.5 Influence of the viscosity of continuous phase on mass transfer of
single drop………………………………………………………………….. 49
4.6 Influence of the viscosity of disperse phase on mass transfer of 50
4.7 Influence of residence time and drop diameter on mass transfer rate
in high viscosity system…………………………………………………… 51
4.8 The sensitivity of diffusion coefficient ………………………………… 54
5.1 Concept of interactions effects in an extraction column……………….. 57
5.2 Schematic illustration of the ReDrop algorithm ………………………... 58
5.3 Concept of design column………………………………………………… 59
5.4 Schematic representation of the pilot-plant scale pulsed sieve-tray
column used in this work………………………………………………….. 61
5.5 Comparison of experimental and calculated Sauter mean diameter… 71
5.6 Drop-size distribution in a high-viscosity system……………………….. 72
5.7 Comparison of experimental and calculated hold-up………………….. 73
5.8 Influence of hole diameter of sieve tray on the extraction process for
high viscosity system ………...…………………………………………… 76









viiiList of Tables

3.1 Correlations are used for predictions of the sedimentation velocity
of drops by Wagner (1999)…………………………………………….. 8
3.2 The systems and concentrations to investigate the sedimentation of
single drops in high-viscosity system…………………………………... 15
3.3 Physical properties of systems used to investigate the
sed