1.

Introduction

1

2.

Review of Literature

1

2.1

Alkali Removal Mechanisms

1

2.2

2

2.2.1

Thermogravimetric Studies

2

2.2.2

Packed Bed Studies

3

2.3

Materials

4

2.3.1

Emathlite and Fuller’s Earth

5

2.3.1.1

Effects of Exposure Time

7

2.3.1.2

Effect of Water Vapor

10

2.3.1.3

Effects of Temperature

10

2.3.1.4

Effects of Gas Concentration

11

2.3.2

Bauxite

12

2.3.2.1

Effects of Gas-Phase Alkali Concentration

13

2.3.2.2

Effect of Sorbent Bed Temperature

15

2.3.2.3

Effect of Superficial Gas Velocity

15

2.3.2.4

Effect of Gas Hourly Space Velocity

15

2.3.2.5

Release of Alkali from Activated Bauxite

16

2.3.3

Diatomaceous Earth

16

2.3.3.1

Alkali Capture Efficiency

16

2.3.3.2

Effect of Time Duration

17

2.3.4

Kaolinite

20

2.3.5

Low-Temperature Coal Char and Gasifier Ash

20

2.3.6

Attapulgus Glay

21

2.3.7

Burgess No. 10 Pigment

23

2.3.8

Silica Gel

23

2.3.9

Dolomite and Calcined Dolomite

23

2.4

Modeling

23

3.

Materials and Methods

24

3.1

Fuel

24

3.2

Getter Materials

24

3.3

Experimental Methods

24

4.

Results and Discussion

33

4.1

Fuel Properties

33

4.2

Test Conditions

35

4.3

Gasifier Bed Material

38

4.4

Filter Char

38

4.5

Results from Baseline Test, 76G-B

41

4.6

Alkali Getter Tests

44

4.6.1

Alkali Getter Materials

44

4.6.2

Test Results

45

4.6.2.1

Test Conditions

45

4.6.2.2

Getter Visual Appearance

46

4.6.2.3

Getter Material Bulk Analyses

52

4.6.2.4

Getter Material Surface Analyses

56

4.6.2.5

Getter Reactor Exit Gas

56

4.6.2.6

Mass Balances

58

4.6.2.7

Comparison of Treatments

62

5.

Summary and Conclusions

63

6.

References

68