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Return to Maintenance and Operation of the U.S. DOE Alternative Fuel Center

Life Cycle Assessment of a Biomass Gasification
Combined-Cycle System - December 1997.

Mann, Margaret K.
Spath, Pamela L.

NREL Life Cycle Assessment

Part 1, Pages 1 - 78, 4.45 MB
Part 2, Pages 79 - 160, 3.76 MB

Table of Contents

Units of Measure

1

Abbreviations and Terms

2

1.0

Introduction

3

2.0

Methodology

4

2.1

System Boundaries and Data Availability

5

2.2

Methodology Energy Considerations

9

2.3

Methodology Comparison with Other Systems

9

2.4

Methodology Sensitivity Analysis

9

2.5

Accounting

10

2.6

Time Frame and Issues in Assessing Environmental Consequences

12

3.0

Technoeconomic Analysis

13

3.1

Biomass Combined Cycle System Description

16

3.2

Model Description

16

3.2.1

Wood Preparation and Drying

17

3.2.2

Gasification

18

3.2.3

Gas Turbine

18

3.2.4

General Plant Requirements

19

3.3

Economic Analysis

19

3.3.1

Economic Analysis Methodology

19

3.3.2

Capital Cost Estimates

20

3.3.3

Overall System Performance

21

3.3.4

Economic Analysis Results

21

4.0

Description of Process Blocks Studied in the LCA

22

4.1

Base Case Feedstock Production Assumptions

23

4.1.1

Yield Assumptions and Land Requirements

23

4.1.2

Base Case Fertilization Assumptions

24

4.1.3

Base Case Herbicide and Pesticide Use

25

4.1.4

Water Consumption by Biomass Plantation

27

4.1.5

Biogenic Emissions

27

4.1.6

Transportation of Farm Chemicals

27

4.1.7

Plantation Operations

28

4.1.8

Soil Carbon Sequestration Base Case

31

4.2

Base Case Biomass Transportation Assumptions

33

4.3

Base Case Power Plant Construction & Decommissioning Assumptions

34

4.4

Base Case Power Generation Assumptions

35

4.4.1

Biomass Storage & Drying

37

4.4.2

Gasifier/Combustors

38

4.4.3

Gas Turbine and HRSG

39

4.4.4

Water Requirements & Treatment

39

5.0

Base Case Results by Impact Category

40

5.1

Air Emissions

44

5.1.1

Carbon Dioxide Emissions

46

5.1.2

Air Emissions from the Power Plant:  Non-Methane Hydrocarbons, NOx, and Sox

54

5.1.3

Particulate Emissions

56

5.1.4

Carbon Monoxide Emissions

56

5.2

Water Emissions

56

5.3

Energy and Resource Consumption

56

5.4

Solid Waste

65

6.0

Results Specific to the Three Major Subsystems

65

6.1

Base Case Feedstock Production Results

65

6.2

Base Case Biomass Transportation Results

72

6.3

Base Case Power Plant Construction & Decommissioning Results

72

6.4

Base Case Power Generation Results

78

 

7.0

Sensitivity Analysis

79

7.1

Feedstock Sensitivity Analysis

84

7.2

Transportation Sensitivity Analysis

84

7.2.1

Mode of Transportation

84

7.2.2

Transportation Distance

88

7.3

Power Plant Construction & Decommissioning Sensitivity Analysis

88

7.4

Land Filling Versus Recycling Sensitivity Analysis

89

7.5

Power Generation Sensitivity Analysis

89

7.5.1

NOx Produced

89

7.5.2

Power Plant Efficiency

89

7.5.3

Operating Capacity Factor

90

8.0

Impact Assessment

90

9.0

Summary of Results and Discussion

92

10.0

Future Work

94

11.0

Related Studies

94

12.0

Acknowledgements

96

13.0

References and Pertinent Literature

97