Energy From Waste on the Isle of Mull: A Feasibility Study of an

0,46

MB

Anaerobic Digestion Plant

106

stron

5245

ID

University of Strathclyde

2004

rok

Contents

1 Introduction 1

1.1 Project Outline 1

1.2 Project Location 1

1.3 Report Structure 3

2 Background 4

2.1 Project Overview 4

2.1.1 Mull - Waste Management 4

2.1.2 Mull - Energy from Waste 5

2.2 Waste Legislation 5

2.2.1 EU Landfill Directive 1999/31/EC 6

2.2.2 EU Animal By-Products Regulation 1774/2002 11

2.2.3 Animal By-Products (Scotland) Regulations 2003. SSI 2003/411 13

2.2.4 EU Draft Biowaste Directive 14

2.3 Renewable Energy Legislation 15

2.3.1 UK and Scottish Legislation 15

2.3.2 Renewables Obligation Scheme 15

2.3.3 Renewable Sector Development 16

2.4 Energy from Waste 17

2.4.1 Combustion of Municipal Solid Waste 18

2.4.2 Combustion of Forestry and Agricultural Waste: 18

2.4.3 Landfill Gas 19

2.4.4 Gasification and Pyrolysis 20

2.4.5 Anaerobic Digestion 21

2.5 Mull and the case for Anaerobic Digestion 22

2.6 Project Strategy 23

2.6.1 Waste Data 24

2.6.2 Technology, Biogas Yield and Energy Use 24

2.6.3 Policy and Funding 24

3 Biogas Technology 26

3.1 Introduction 26

3.2 Anaerobic Digestion- Biochemical Processes 26

3.2.1 Hydrolysis 26

3.2.2 Acidogenesis 28

3.2.3 Methanogenesis 28

3.3 Operating Parameters 29

3.3.1 pH 29

3.3.2 Temperature of digestion 30

3.3.3 Dry Solids content 30

3.3.4 Retention Time 31

3.3.5 Organic Loading Rate 31

3.3.6 Carbon to Nitrogen ratio 31

3.3.7 Mixing 32

3.4 Biogas Production and By- Products 32

3.5 Biogas Technology Options 34

3.6 AD Process and Premises requirements in Scotland/UK 35

3.6.1 Regulations Applicable to Biogas & AD premises 35

3.6.2 Hygiene Requirements 37

3.6.3 Processing standards 38

3.7 Proposed Biogas Plant for Mull 39

3.7.1 Waste Reception Area 41

3.7.2 Waste shredding and preparation 41

3.7.3 Raw Waste Buffer Storage 41

3.7.4 Anaerobic Digester 41

3.7.5 Pasteurisation 42

3.7.6 Heat Exchangers 42

3.7.7 Gas Collection and Holder 43

3.7.8 Digestate Storage 43

3.7.9 Heat & Power Generation 43

4 Mull AD Potential 46

4.1 Previous Waste Audit Data 46

4.2 Waste Audit Data Methodology 2003 47

4.2.1 Slaughterhouse waste: 47

4.2.2 Aquaculture 48

4.2.3 Agriculture 48

4.2.4 Food Waste 50

4.2.5 Sewage 50

4.3 Consultancy report 50

4.4 Waste Data 2004 53

4.4.1 Slaughterhouse waste 54

4.4.2 Aquaculture 56

4.4.3 Agriculture 58

4.4.4 Food Waste 60

4.4.5 Paper and Cardboard 61

4.4.6 Cooking Oils 62

4.4.7 Sewage 63

5 Energy Calculations 68

5.1 Biogas Yield 68

5.2 Buffer and Digester Tank Storage. 69

5.3 Energy Yield 70

5.4 Energy Usage on Sgriob Ruadh Farm 71

5.4.1 Heat Energy 71

5.4.2 Electricity Requirements 72

6 Financial Issues 74

6.1 Project Costs 74

6.2 Project Income 75

6.3 Project Funding 77

6.3.1 Carbon Trust 77

6.3.2 Energy Savings Trust 78

6.3.3 Highlands and Island Enterprise 78

6.3.4 EU/International Funding 80

7 Conclusions 82

7.1 Conclusion 82

7.2 Recommendations 83

Appendix A Energy calculations 1

Appendix B - Abbreviations 3

Appendix C References 4