Executive Summary

1

1.

Chapter 1:  Introduction

2

1.1

Introduction

2

1.2

Objectives

2

2.

Chapter 2:  Literature Review

4

2.1

Introduction

4

2.2

Coal Characteristics

4

2.3

Emerging Technologies for Coal Utilization

5

2.3.1

Integrated Gasification Combined Cycle (IGCC)

5

2.3.2

Coal Gasification

6

2.4

Hot Gas Desulfurization

7

2.5

High Temperature Sorbents

8

2.5.1

Zinc-Based Sorbents

8

2.5.2

Manganese-Based Sorbents

8

2.6

Cold Versus Hot Sulfur Clean-Up

8

2.7

Regeneration

9

2.8

References

11

3.

Chapter 3:  Thermodynamic Considerations

15

3.1

Introduction

15

3.2

Sulfidation Thermodynamics

15

3.3

Regeneration Thermodynamics

20

3.4

References

23

4.

Chapter 4:  Kinetic Considerations

24

4.1

Introduction

24

4.2

Single Pellet Modeling:  The Shrinking Core Model

24

4.2.1

Diffusion Through Gas Film Controls

25

4.2.2

Diffusion Through Product Layer Controls

27

4.2.3

Chemical Reaction Controls

29

4.3

Comparison of Models for Gas-Solid Reactions

30

4.4

Fixed-Bed Modeling

31

4.5

References

34

5.

Chapter 5:  Experimental Procedure

35

5.1

Pellet Manufacture

35

5.1.1

Feed Materials

35

5.1.2

Formula Designations

36

5.1.3

Preparation

37

5.2

Pellet Characterization

37

5.2.1

Thermogravimetric Analysis (TGA)

37

5.2.2

Fixed-Bed Testing

38

5.2.3

Strength Testing

42

5.2.4

X-Ray Diffraction (XRD)

42

5.2.5

Manganese Analysis

43

5.2.6

Sulfur Analysis

43

5.2.7

Pore Structure Analysis

43

6.

Chapter 6:  Results

44

6.1

Introduction

44

6.2

TGA Results

44

6.3

Fixed-Bed Testing

45

6.3.1

Sulfidation

46

6.3.2

Regeneration

50

6.3.3

Effects of Varying Sulfidation Conditions

53

6.4

Fixed-Bed Modeling

54

6.5

Sulfur Analysis

57

6.6

Strength Testing

58

6.7

X-Ray Diffraction (XRD)

59

6.8

Pore Structure Analysis

60

6.9

References

61

7.

Chapter 7:  Conclusions

116

8.

Notation

118