Feasibility Study: Grain-dust Burner

3,79

MB

136

stron

5272

ID

University of Strathclyde

2006

rok

Table of Contents

1) Introduction . 1

1.1 Project Definition 1

1.1.1 Brief . 1

1.1.2 Aim. 1

1.1.3 Objectives and Deliverables 1

1.1.4 Conclusion Summary. 2

1.2 Background . 3

1.2.1 Biomass and Bio-energy 3

1.2.2 Grain Drying . 3

1.2.3 Grain-dust . 6

1.2.4 Dust Burners 8

1.2.5 Potential Issues 8

2) Composition and Combustion . 10

2.1 Composition of Biomass 10

2.1.1 Fuel Quality. 11

2.2 Chemical Make-up of Barley. 11

2.2.1 Elements Influencing Ash Formation 12

2.2.2 Elements Influencing Emissions and Corrosion . 12

2.3 Current Chemical Data . 13

2.3.1 BIOBIB - A Database for Biofuels 14

2.3.2 Jiang et al (2005): Analysis of Grain Screenings . 15

2.3.3 CEN/TS 14961. 15

2.3.4 Obernberger et al (2004) 16

2.4 Chemistry of Combustion 17

2.4.1 Complete combustion 17

2.4.2 Combustion of Biofuels . 17

2.4.3 The Energy Value of Biomass . 19

3) Comparable Technology . 21

3.1 Extent of Current Technology . 21

3.2 Straw Biomass . 21

3.2.1 Case Study . 22

3.2.2 Economics of Straw Biofuel 23

3.2.3 Straw Ash Characteristics . 23

3.2.4 Comparison of Straw and Grain . 24

3.3 RDF (Refuse Derived Fuel). 25

3.3.1 RDF Firing Processes . 26

3.4 Pellets and Powder 27

3.4.1 Fuel Powder and Handling . 28

4) Slag Formation & Emissions 30

4.1 Issues . 30

4.2 Ash. 31

4.2.1 Ash Formation. 31

4.2.2 Ash Management . 32

4.3 Slag 33

4.3.1 Slag Formation 33

4.3.2 Slag Prevention . 35

4.4 Emissions. 37

5) Analysis . 39

5.1 Aims. 39

5.2 Particle Size. 41

5.2.1 Experimental Analysis. 42

5.2.2 Results and Conclusions 44

5.3 Moisture content 49

5.3.1 Experimental Analysis. 49

5.3.2 Results and Conclusion . 50

5.4 Calorific values . 52

5.4.1 Experimental Analysis. 52

5.4.2 Results . 55

5.4.3 Conclusions . 58

5.5 Ash Content . 61

5.5.1 Experimental Analysis. 61

5.5.2 Results and Conclusion . 62

5.6 Elemental Analysis 66

5.6.1 Carbon, Hydrogen, and Oxygen Content 67

5.6.2 Chlorine, Nitrogen and Sulphur Content 67

5.6.3 Results and Conclusions 68

5.7 Analysis Summary . 70

6) Dust Burners 71

6.1 Principles of Solid Biofuel Combustion 71

6.1.1 Current Dust Burning Technology 72

6.2 Commercial Models 73

6.2.1 Wood Dust Burners . 73

6.2.2 Biofuel Burners 77

6.2.3 Applicable Technology 79

6.2.4 Biomass Combustion System . 82

6.2.5 Dust Burner Selection . 83

7) Design and Integration 85

7.1 LBE Biomass Dust Burner 85

7.2 Current Drying System 87

7.2.1 Oil Burners 88

7.2.2 Furnace . 88

7.3 LBE Grain-dust Analysis. 90

7.3.1 Results Comparison. 90

7.4 Feasibility of Grain-dust Fuel. 93

7.4.1 Fuel Quality. 93

7.4.2 Fuel Flow-rates . 94

7.4.3 Barley Contamination . 94

7.5 Burner Integration. 96

7.5.1 Initial Concepts . 96

7.5.2 Implications of LBE Results 97

8) Conclusions and Recommendations 99

8.1 Summary and Conclusions 99

8.1.1 Research Summary 99

8.1.2 Analysis Summary . 100

8.1.3 Design Summary 102

8.2 Recommendations 105

9) Sources of Information 107

9.1 References . 107

9.2 Background Reading . 110

9.3 Standards. 112

10) Appendices i

10.1 Original Brief and Deliverables. i

10.2 Chemical Data iii

10.3 Analysis .iv

10.3.1 Formulae for Conversion between Different Bases iv

10.3.2 Particle Size Distribution iv

10.3.3 Elemental Analysis .v

10.3.4 Conversion between Gross and Net Calorific Values v

10.3.5 Complete Results for Calorific Values vi

10.3.6 Net Calorific and Gross Calorific values vii

10.3.7 Complete results from LBE viii

10.3.8 LBE Particle Distribution .ix

10.4 Relevant Patents .x

10.4.1 US4457695 .x

10.4.2 US5127346 xi

10.5 Designxi

10.5.1 Drawings from LBE.xi