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Simultaneous Production of High-Purity Hydrogen and Sequestration-Ready CO2 Table of Contents

Simultaneous Production of High-Purity Hydrogen and Sequestration-Ready CO2 From Syngas,
Final Technical Report - December 2003

Linda Denton
Hana Lorethova
Tomasz Wiltowski
Court Moorefield
Parag Kulkarni
Vladimir Zamansky
Ravi Kumar

GE Energy and Environmental Research

In this pdf format, this document has 108 pages and is 4.73MB.

Table of Contents

DISCLAIMER ii
ABSTRACT iii
TABLE OF CONTENTS iv
LIST OF TABLES ix
1.0 INTRODUCTION 1
2.0 EXECUTIVE SUMMARY 3
3.0 EXPERIMENTAL 5
 

3.1

 Lab Evaluation, Materials Evaluation, and Process Development (Tasks 1, 3, 4) 5
  3.1.1 Description of Thermogravimetric Analysis (TGA) 5
3.1.2 Description of Cold Flow Fluidized Bed Modeling 5
3.1.3 Cold Flow Fluidized Bed Equipment and Instrumentation 7
3.1.4 Pressurized Fluidized Bed 8
3.1.5 Adsorption and Regeneration of Solids 17

3.2

 Bench Scale System CO2 Separation of Syngas with a Fixed Bed (Task 5) 17
 

3.2.1

 Modifications to the Bench Scale System 18

4.0

 RESULTS AND DISCUSSION 21
 

4.1

 TGA Results (Task 1) 21
 

4.1.1

 TGA Introduction 21

4.1.2

 Kinetic Model for Reduction of Iron Oxide using Carbon Monoxide 26

4.1.3

 Results and Discussion (TGA and Kinetic Model) 30

4.2

 Economic Assessment (Task 2) 36

4.3

 Cold Flow Modeling (Task 3) 36
  4.3.1 Fluidized Bed Theory 36
4.3.2 Cold Flow Model Results 36

4.4

 High Flow Rate Study (Task 3) 43
  4.4.1 Reactions Involving Lime and Limestone 45
4.4.2 Reactions with Iron 48
4.5 Theory Applied to the Problem (Task 4) 54
4.6 Dispersion Model Analysis (Task 4) 57
  4.6.1 Factor Response Experiment 63
4.6.2 Solids Addition to COx Conversion Compared to WGS in Empty Reactor 68
4.6.3 Addition of CaO 70
4.6.4 Mass Balance 73
4.6.5 Cycling of Hydrogen Production and Regeneration of Solids 74
4.6.6 SEM Analysis 78

4.7

 Cyclic Fixed-bed Reactor (Task 5) 85

5.0

 CONCLUSIONS 88
 

5.0.1

 Recommendations 90
6.0 REFERENCES 92
7.0 NOMENCLATURE 96
8.0 DEFINITION OF VARIABLES 96
9.0 LIST OF ABBREVIATIONS 99
 
LIST OF FIGURES

Figure 1

 Fluidized Bed Reactor Schematic 10
Figure 2 Section Details - Reactor 11
Figure 3 Frit Housing of Fluidized Bed Reactor 12
Figure 4 Top Flange of Inner Tube of Fluidized Bed Reactor 13
Figure 5 Inner Tube of Fluidized Bed Reactor with Top Flange and Outlet Pipe 13
Figure 6 Installation of Inner Tube in Reactor 14
Figure 7 Assembled and Mounted Fluidized Bed Reactor, Furnace and Preheater 15
Figure 8 Steam Generator Located in Bottom Flange of Reactor 16
Figure 9 Top: Bread-board 100 kW H2 Production Unit. Bottom: Modified Prototype 200 kW H2 Production Unit (From DOE Grant "Conversion of Natural Gas to PEM Fuel Cell Grade H2",
Contract # DE-FC02-97EE50488		 18
Figure 10 Illustration of the Autothermal Cyclic Reforming (ACR) Process: Air Regeneration step 19
Figure 11 Illustration of the Autothermal Cyclic Reforming (ACR) Process 19
Figure 12 Gibbs Free Energy vs. Temperature 25
Figure 13 Gibbs Free Energy vs. Temperature 26
Figure 14 X-Ray Diffraction Pattern for the As Received Iron Oxide Samples - Fine (powder) and Coarse (particle) 31
Figure 15 Experimental TGA Curves Obtained Via Reduction of Coarse Iron Oxide Samples in Pure CO at 800, 850 and 900oC 32
Figure 16 Experimental TGA Curves Obtained Via Reduction of Fine Iron Oxide Sample in Pure CO at Temperatures Ranging from 400oC - 900oC 33
Figure 17 Variation of Rate Constant with Temperature for the Reactions in Iron (III) Oxide Reduction in CO 34
Figure 18 X-ray Diffraction Pattern for the Reduced Iron Oxide Samples in 40 and 50 % CO Atmospher at 850oC 35
Figure 19 Pressure Drop Across Bed-CaCO3 vs. Flow Rate-Cold Flow Fluidization Study 39
Figure 20 Pressure Drop Across Bed-Fe2O3 vs. Flow Rate-Cold Flow Fluidization Study 40
Figure 21 Pressure Drop Across Bed - CaO vs. Flow Rate - Cold Flow Fluidization Study 41
Figure 22 Pressure Drop Across Bed Fe2O3:CaO (1:2) Mixture vs. Flow Rate - Cold Flow Fluidization Study 41
Figure 23 Pressure Drop Across Bed Fe2O3:CaO (1:2) Mixture vs. Flow Rate - Cold Flow Fluidization Study 42
Figure 24 Pressure Drop Across Bed - CaCO3:CaO:Fe2O3 Mixture (1:1:1) vs. Flow Rate - Cold Flow Fluidization Study 42
Figure 25 Influence of CO2 Concentration and Pressure on Dissociation Temperature of CaCO3 (Boynton [34]) 45
Figure 26 Iron Oxide Equilibrium at Varying Temperatures and Percentages of H2 and CO (Szekely[45]) 50
Figure 27 Outlet Gas Composition of Empty Reactor - 725oC, 50 psi 60
Figure 28 Effect of Fe2O3 on Empty Reactor C-Curve - 725oC, 50 psi 62
Figure 29 Effect of Fe2O3 on Empty Reactor C-Curve - 800°C, 250 psi 62
Figure 30 Effect of Fe2O3 on Empty Reactor C-Curve - 725°C, 515 psi 63
Figure 31 Response Surface Results of Percentage of CH4 Appearing in outlet Gas in First Fifteen Minutes 67
Figure 32 Adsorption of COx - 1:7 Fe2O3:CaO - 725°C, 250 psi 71
Figure 33 Solids of 1:7 Fe2O3:CaO Mixture After One Hydrogen Generation Cycle 76
Figure 34 Composition of Outlet Gas During Cycling at 250 psi 77
Figure 35 Reactor and Furnace Temperatures During Cycling at 250 psi 78
Figure 36 Fe2O3, Detail, Mag. 6000x, As Received 79
Figure 37 Fe2O3, Detail, Mag. 6000x, Test 800°C 250 psig 79
Figure 38 Fe2O3, Detail, Mag. 6000x, Test 725°C, 515 psig 80
Figure 39 MIX, Fe2O3,  Detail, Mag. 6000x, Test 725°C, 50 psig 80
Figure 40 MIX, detail, mag. 6000x, test 725C, 250 psig, regeneration cycle 81
Figure 41 CaO, Detail, Mag. 6000x, As Received 82
Figure 42 MIX, CaO Detail, Mag. 6000x, 725°C, 515 psig 83
Figure 43 MIX, CaO Crack Detail, Mag. 6000x, 725°C, 515 psig 83
Figure 44 MIX, CaO Detail, Mag. 6000x, 800°C, 515 psig 84
Figure 45 MIX, CaO Detail, Mag. 6000x, Test 725°C, 250 psig, regeneration cycle 85
Figure 46 Typical Syngas Outlet concentrations of reactor 1 (Ni) Being Delivered to Reactor 2 (FeO, CaO) in Fixed Bed Reactor (From DOE Grant "Conversion of natural gas to PEM Fuel Cell Grade H2", Contract # DE-FC02-97EE50488) 86
Figure 47 Theoretical Temperature Swing Requirement for FeO/CaO Fixed Bed Reactor 87
Figure 48 Syngas Fe2O3/CaO Bed Inlet and Outlet Concentrations (Fixed Bed) 88
     
  LIST OF TABLES  
Table 1 Solid Particle Characteristics - Cold Flow Fluidization Study 8
Table 2 Activation Energies for Iron Oxide Reduction Reported in Literature 23
Table 3 Particle Size Measurements 23
Table 4 Expressions for Concentration of B and C 24
Table 5 Estimated Activation Energies and Frequency Factors for the Various Reactions Involved in Iron Oxide Reduction with 100% CO Gas Stream 35
Table 6 Minimum Fluidization 38
Table 7 High Flow Data Summary - Cold Flow Fluidization Study 44
Table 8 Chemical Processes and Heat of Reactions for Reactor and Regenerator 56
Table 9 Effect of 50g Fe2O3 on Dispersion Characteristics 63
Table 10 Factor-Response for Initial Response Surface Study of Hydrogen Production 64
Table 11 Significant Effects on Production Response 65
Table 12 Additive Effect on Fractional Conversion of CO to CO2 by the Reduction of Iron Oxide 69