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Hydrodynamics of the Three-Phase Slurry Fischer-Tropsch Bubble Column Reactors.
Final Report - 1990

Bukur, Dragomir B.
Daly, James G.
Patel, Snehal A.

Texas A&M

Table of Contents 707kb

  List of Tables vi
List of Figures x
Section 1
Abstract xix
Objectives and Scope of Work xx
Executive Summary xxii
Recommendations For Future Work xxvii
Section 2


Introduction 1
    Overview of Fischer-Tropsch Studies in Bubble Columns 3
Mass transfer coefficient 5
Heat transfer coefficient 6
Gas holdup and bubble size distribution 6
Flow regime characterization 10
Effect of solids 10
Effect of liquid velocity 11
Overview of Nuclear Density Gauge Studies 12
Objectives of This Study 16
Section 3


Measurement of Gas Holdups By Conventional Techniques 17
    Experimental Apparatus and Operating Procedure 17
Experimental Conditions 29
Data Acquisition and Reduction Procedures for Gas Holdups and Solids Concentration Profiles 29
Average gas holdup - glass columns 32
Phase fractions - stainless steel columns 32
Pressure measurements 32
Solid concentration measurements 36
Holdup calculations 42
Section 4
Results and Discussion 47
Description of the flow field 47
Gas holdup results 49
Effect of slurry velocity 51
Effect of solids concentration 62
Effect of solids type and size 77
Section 5
Effect of liquid medium 82
Effect of distributor type 85
Effect of column diameter 87
Physical Properties and Average Gas Holdup Correlations 92
Physical property measurements 92
Density measurements 92
Viscosity measurements 94
Surface tension measurements 95
Gas holdup correlations 97
Section 6


Measurement of Phase Fractions By Gamma-Ray Densitometry 111
    Theoretical Discussion 111
Models used to describe three-phase systems 115
Case I. Perpendicular alignment 115
Case II. Parallel alignment 119
Comments on the alignment of the phases 122
Source Selection and Sensitivity Analysis 123
Experimental Apparatus and Operating Conditions 130
Movable assembly mechanism (MAM) 130
Sources and detectors 133
Nuclear electronics 135
Calibration procedures 141
Data Acquisition and Reduction Procedures 143
Section 7
Gas holdups in two-phase systems 147
Gas holdups in three-phase systems 154
Discussion of Results 154
Independent treatment of all three phases 155
Two-phase and pseudo two-phase results 157
Section 8


Axial Solids Distribution 184
    Semi-Infinite Dispersion Model 184
Summary of Solids Concentration in the Column and Storage Tank 188
Results and Discussion 193
Section 9


Bubble Size Distributions 211
    Experimental Techniques for Measurement of the Disengagement Profile 215
Theory 216
Case I. Constant rate disengagement process 217
Estimating bubble rise velocities and gas holdups during constant rate disengagement 223
Data Acquisition and Reduction Procedures 228
Section 10
Discussion of Results 231
Effect of axial position 247
Effect of column diameter 249
Comparison of results obtained in the glass and stainless steel bubble columns 251
Section 11


Flow Regime Characterization 256
    Theoretical Background 256
Discussion of Results 262
Flow regime transitions based on the MSE 268
Flow regime transitions based on the PSD 279
Section 12


Nomenclature 294


Literature Cited 300


Acknowledgements 311