The Role of Anaerobic Digestion Technology in Treating Organic Waste UK Experience

Transcription

1 The Role of Anaerobic Digestion Technology in Treating Organic Waste UK Experience Presentation to GreenCape Networking event, 23 rd August 2016 Andrew Street Director, SLR Consulting 1

2 PRESENTATION OVERVIEW Setting the scene technology options and selection The UK journey towards a circular economy and the role of waste treatment technology The role that Anaerobic Digestion is playing in treating organic waste streams South African Case Study Conclusions 2

3 PRESENTATION OVERVIEW Setting the scene technology options and selection The role that Anaerobic Digestion is playing in treating organic waste streams The UK journey towards a circular economy and the role of waste treatment technology South African Case Study Conclusions 3

4 EMERGENCE OF THE CIRCULAR ECONOMY Historic linear model of take-make-consume and dispose assumes resources are abundant, available and cheap to get rid of The last years has seen a dramatic change in the way we view and treat waste. The Circular Economy sees waste as a resource Materials reclaimed and reused or recycled as secondary raw materials for new products Organic waste a source of soil nutrients Energy generated from any residual waste that cannot be recycled Reduces pressure on natural resources / supply chains Contributes to sustainable economic growth and employment 4

5 PRINCIPAL WASTE TREATMENT / CONVERSION TECHNOLOGY OPTIONS Non-thermal: Composting [organic waste] Anaerobic Digestion (AD) [principally organic waste] Mechanical Biological Treatment (MBT / RDF production) Mechanical Heat Treatment Autoclaving [residual waste] (Note that all these technologies are intermediate processes and markets are required for the products) Thermal: Incineration with energy recovery [residual waste / RDF] Advanced Thermal Treatment (ATT - gasification / pyrolysis / plasma arc) [principally RDF / refined RDF] Landfill will still be required for final post-treatment residues (but much reduced quantities) 5

6 TECHNOLOGY SELECTION CRITICAL ISSUES National / Provincial / Municipality strategy and policy Collection strategy (segregated or mixed streams) and impact on composition - and future changes Seasonal variations in composition (impact on input stream) Financial drivers: Availability and cost of landfill Landfill or incineration levies / taxes (current or future) Enhanced tariffs for renewable energy generation / use Status of the technology (fully commercial or otherwise) and bankability Markets for process outputs (demand and commercial context): Recyclable streams (quality and variability of outputs) Compost / digestate (quality and variability of outputs) Compost like output / RDF / biomass (quality of outputs) Bio-fuels 6

7 MAIN PITFALLS AND LESSONS FROM THE PAST Failure to properly understand the waste flows quality and quantity Failure to recognise that the waste is variable and will change significantly over time Failure to match waste feedstock (including variability) with technology Failure to select technology that is proven - and therefore bankable Failure to understand the character of the process outputs Failure to have established, sustainable and commercially viable markets for all process outputs Failure to recognise that market demands can, and will change over time Success comes through a thorough understanding of waste flows, technology and markets for process outputs and the interfaces 7

8 PRESENTATION OVERVIEW Setting the scene technology options and selection The UK journey towards a circular economy and the role of waste treatment technology The role that Anaerobic Digestion is playing in treating organic waste streams South African Case Study Conclusions 8

9 THE UK JOURNEY TOWARDS A CIRCULAR ECONOMY In Europe we have EU-wide legislation in place to force biodegradable waste away from landfill to alternatives Relatively high targets for recycling (50% plus) Some countries have landfill bans, some have landfill levies Many have renewable energy incentives (Feed-in Tariffs, etc) The drivers have therefore been in place over the last years to plan and develop new waste collection / treatment and disposal infrastructure In the last 5-10 years one of the largest waste management markets in the world has been the UK (around R175 * billion spend to 2020) Many hundreds of new facilities have been built, are under construction, or are planned of all types The knowledge gained of every type of treatment / management technology is therefore extensive we ve learned how to make choices! * NOTE Current (August 2016) exchange rate R / of

10 KEY DRIVER LANDFILL LEVY EVOLUTION Escalator set at R140/tonne; Levy has now reached R1,500tonne (and increasing with inflation) Initially set at R140/tonne 10

11 ORGANICS: ANAEROBIC DIGESTION Existing plants Prospective plants The latest map of UK AD facilities (opposite) shows a significant number of existing plants, and a proliferation of prospective sites. Please note that this map includes ADs with feedstock including segregated food waste, food processing wastes, agricultural wastes and energy crops (but excludes sewage treatment works). 11

12 ANAEROBIC DIGESTION (continued...) The UK has seen recent rapid growth in AD capacity This has led to concerns over the over provision of AD capacity 12

13 AD FACILITIES (continued...) Top 20 largest AD facilities (focussing on those which are operational or in construction): Operator Facility name Status Throughput (ktpa) Area ReFood Dagenham AD In construction Updated 160 Dagenham Earthly Energy In construction 129 North Yorkshire Lake District Biogas Ltd Lake District Biogas AD In construction 126 Wigton Biffa Biffa - Cannock (Poplars) Operational 120 Cannock PDM ReFood Operational 115 Doncaster BioConstruct NewEnergy Ltd Imperial Park AD In construction 110 Middlesborough Rockscape Energy Ltd Operational 101 North Moor Farm Shanks Cumbernauld / Orgworld Operational 100 Glasgow BRITISH SUGAR PLC Bury St Edmunds In construction 97 Bury St Edmunds Roseisle Speyside Whisky Roseisle Speyside Whisky Roseisle Operational 90 Distillery Distillery PDM ReFood Operational 90 Widnes Diageo Ltd Glenfiddich Distillery Operational 88 Keith AC Shropshire Ltd Green Lodge Farm Operational 86 Leicester Corsock Farm Corsock Farm Operational 80 Dalbeattie JFS Clapham Lodge Biogas Ltd Clapham Lodge In construction 80 Northallerton Tamar / Fred Walter & Sons Ltd Operational 76 Sutton Grange 13

14 UK INCENTIVES TO SUPPORT DEVELOPMENT OF AD Feed-in Tariffs( generation tariff and export tariff) Facility Size Pence / kwh Rand / kwh Total installed capacity of 250kWe or less Total installed capacity between 250kWe and 500kWe Total installed capacity in excess of 500kWe Renewable Obligation Certificates currently set at 1.8 ROCs/MWh. The value of ROCs varies as they are traded. Replaced by Contracts for Difference (CfD) for larger generators of 5MWe and above. Renewable Heat Incentive (RHI), provides a fixed income (per kwh) to generators of renewable heat, and producers of renewable biogas and bio-methane. Current rates: Facility Size Pence / kwh Rand / kwh Small biogas combustion (less than 200 kwth) Medium biogas combustion (between 200 and 600 kwth) Large biogas combustion (greater than 600 kwth) Bio-methane injection (all scales)

15 RESIDUAL WASTE: PRE-TREATMENT FACILITIES Established Newly developed Prospective Existing and prospective pretreatment facilities (shown opposite) outnumber thermal processing plants 15

16 PRE-TREATMENT FACILITIES (continued...) Existing 50 facilities operational or in construction (6 Mtpa capacity). Prospective facilities with planning granted / proposed would double capacity to 12 Mtpa (though again many will not be realised). 16

17 THERMAL FACILITIES The map opposite illustrates locations of UK conventional thermal facilities. Established Newly developed Prospective Plants shown include: Established plants operational in, or before, Newly developed plants operational post 2008, or in construction. Prospective plants which have planning permission granted, or are at the proposal stage. 17

18 THERMAL FACILITIES (continued...) Existing 41 facilities operational or in construction (over 10 Mtpa capacity) Prospective the same amount of capacity again with planning granted / proposed (though many of these will not be realised). 18

19 ADVANCED THERMAL TREATMENT FACILITIES Existing ATT facilities (mapped opposite) are currently much less numerous than incineration.... however a large number of prospective facilities have been put forward. Existing plants Prospective plants 19

20 ADVANCED THERMAL TREATMENT FACILITIES (continued...) Existing only two known operational residual waste ATT facilities on a significant scale (Avonmouth New Earth and Isle of Wight Energos / Biffa.), with a further four in construction. A further 72 prospective plants though likely that only a small proportion of these will be realised. 20

21 OVERALL IMPACT ON LANDFILL: 90%+ DIVERSION BY

22 PRESENTATION OVERVIEW Setting the scene technology options and selection The UK journey towards a circular economy and the role of waste treatment technology The role that Anaerobic Digestion is playing in treating organic waste streams South African Case Study Conclusions 22

23 ANAEROBIC DIGESTION Basic Description: The bacterial breakdown of suitable organic materials in controlled conditions and in the absence of oxygen producing methane-rich biogas and digestate Suitable feedstock includes: The main AD processes include: Food waste high biogas yields Green / garden wastes moderate / low biogas yields Sewage sludge / livestock slurry low biogas yields Energy crops (maize / silage) high / moderate biogas yields Wet / dry digestion Single stage / two stage Mesophillic (~37C) / Thermophillic (55-59C) Batch flow / continuous flow process Post-treatment as required to meet any quality standards for digestate 23

24 ANAEROBIC DIGESTION: EXAMPLES 24

25 ANAEROBIC DIGESTION: KEY ISSUES / RISKS Benefits: Proven technology with long history of use; AD biogas (methane) provides renewable energy options as heat, electricity, bio-methane vehicle fuel; Output is well-suited for end-use as compost with beneficial properties; Bio-stabilisation of feedstock achieved in less time than for aerobic processes; Fully enclosed wet process minimises odour, particulate and bio-aerosols; Income from sale of electricity, heat and/or methane; Carbon neutral process. Key issues / risks: Higher capital costs compared to in-vessel composting; Complex process that requires close managing and with higher maintenance / opex costs than IVC; Quality and variability of feedstock impact on performance; Identifying a sustainable market for use of digestate; Reliance in enhanced energy tariffs to underpin commercial viability. 25

26 UK electricity generated by anaerobic digestion (GWh) AD IN THE UK ENERGY GENERATED ANNUALLY 1,200 1,

27 0 to to to to to to to to to to Number of AD facilities AD IN THE UK FACILITIES BY DESIGN CAPACITY Proposed Planning granted In construction Operational Feedstock capacity (ktpa) 27

28 0 to to 1 1 to to 2 2 to to 3 3 to to 4 4 to to 5 5+ Number of AD facilities AD IN THE UK FACILITIES BY POWER OUTPUT Proposed Planning granted In construction Operational Rated power output (MW) 28

29 CASE STUDY 1 Anaerobic Digestion Plant, London Client: Foresight Group (private equity) Location: Dagenham, London Scale of Plant: 20,000 tpa IVC (green waste) 30,000 tpa wet AD (segregated food waste) Energy output: 1.5MW e (gas engine, power export to grid) Waste heat to be connected to district heating system Technology provider: IVC TEG AD Anaergia / UTS Gas engines Pro 2 (German) Capital cost: R350 million (Investec / Foresight / GIB / LWARB) Operating costs: R21 million/annum (approx) Date commissioned: February 2012 Principal challenge: de-packaging equipment 29

30 CASE STUDY 2 Anaerobic Digestion Plant, Dunfermline Location: Dunfermline, Scotland Scale of Plant: 43,000 tpa dry fermentation AD (40,000 of co-collected green and food waste; 3,000 of commercial food waste) Energy output: 1.6MW e (gas engine, power export to grid) Digestate: good quality compost for sale Waste heat connected to district heating system Technology provider: AD BioFERM (Viesmann Group) Gas engines ENER-G / MTU Capital cost: R245 million Operating costs: R15 million/annum (approx) Date commissioned: Mid-2014 Why dry fermentation?: Suited to co-mingled food and garden waste with high dry solids content. Suited to operation by local authority direct staff - waste handling operations similar to other waste management activities No dewatering so significantly reduced liquor (compared to wet AD systems) 30

31 CASE STUDY 3 Anaerobic Digestion Plant, Somerset, England Location: South Petherton, Somerset Scale of Plant: 48,100 tpa wet AD (37,100 of agricultural crops; 11,000 of animal manure / slurry) Energy output: 4.2MW th (gas upgrade and export to natural gas grid) Digestate dewatered and used by local farmers Technology provider: AD Biogest Gas upgrade DMT Capital cost: R157 million Operating costs: R29.5 million/annum Date commissioned: under construction (completion early 2016) Principal challenge: gas upgrade relatively new to the UK (well proven in other parts of Europe) 31

32 PRESENTATION OVERVIEW Setting the scene technology options and selection The UK journey towards a circular economy and the role of waste treatment technology The role that Anaerobic Digestion is playing in treating organic waste streams South African Case Study Conclusions 32

33 BIODIGESTION IN SOUTH AFRICA The country already has hundreds of small-scale bio-digesters in rural areas (with gas used for cooking / heating/ lighting etc) There are <40 registered commercial biogas digesters, larger than 100kW, typically on farms, abattoirs, dairy factories etc, i.e. off-grid Of these, there are around 12 industrialscale AD plants at scale >250kW. Almost all of these are for embedded generation, i.e. use of power for onsite industrial facility. Includes plants at industrial /municipal wastewater treatment works Excludes Landfill Gas plants (e.g. Cape Town, Durban, Jo burg) and cogeneration projects in the sugar industry Key Drivers for Development of AD in South Africa: Energy Security; Feedstock availability; Increasing cost of landfill; and Government policies. 33

34 CASE STUDY 4 Bronkorstspruit Biogas Plant, Gauteng Province Plant Details: Installed Capacity: 4.6 MWe Location: Beefcor Farm, Tshwane City, Gauteng Investors: Norfund, Bio2Watt, Chlorophyll, Bertha, Bosch; Lender: Industrial Development Corporation, Johannesburg Feedstock: 120,000tpa of mixed organic (agricultural and food processing) wastes Offtakes: BMW SA car plant (PPA) & c.20,000 tpa fertiliser to Beefcor farm. Constructed by Bosch Projects (as EPC) using Combigas (Denmark) digestion technology (2 x stage thermophillic / mesophillic process) ; Plant produced first power to Eskom grid in October 2015 (via 4 no. Caterpillar CHP engines); Beefcor Site = one of SA s largest beef cattle feedlots; also close to grid connection, feedstock sources and has on-site water supply dams; Process includes dewatering to recover liquor for recirculation and solid digestate for beneficial application to Beefcor farm. 34

35 Bronkorstspruit Biogas Plant Feedstock Supply Feedstocks Solids Tonnes / a Cattle Manure 45,000 Paper sludge 24,000 Liquids Fruit & Veg 8,000 Chicken Abattoir 7,000 Food sludge 6,000 Yogurt 5,000 Ice cream 3,000 Fat Trap 2,000 Total 100,

36 PRESENTATION OVERVIEW Setting the scene technology options and selection The UK journey towards a circular economy and the role of waste treatment technology The role that Anaerobic Digestion is playing in treating organic waste streams South African Case Study Conclusions 36

37 CONCLUSIONS The Circular Economy sees waste as a resource Materials reclaimed and reused or recycled as secondary raw materials for new products Organic waste a source of soil nutrients Energy generated from any residual waste that cannot be recycled Focus often on the front end of product design and waste prevention / reuse rightly so Provision for the treatment and reprocessing of segregated material streams, and the residual stream, is equally important if a move away from landfill reliance is to be achieved National and Provincial Government and Municipalities have the greatest ability to influence decisions on technology selection through policies, byelaws and contractual / procurement decisions. The application of Anaerobic Digestion for the treatment of a range of organic wastes can play a key role in circular economic thinking 37

38 AD - A VIRTUOUS CIRCLE! Waste from human and animal consumption creates more AD feedstock Organic wastes processed through AD to generate biogas and nutrient rich digestate Digestate is used in agriculture for the production of crops Biogas is used as a renewable fuel to reduce the demand for brown energy 38

39 SOUTH AFRICAN MARKET Bio2watt plants: BBP = 1 st commercial scale AD plant in SA to export power to Eskom grid (Oct 2015) ; Fully commercial plant with Financial Case based entirely on revenues from (a) feedstock gate fees and (b) power sales to grid; Based on success of BBP plant, Bio2Watt are developing 2 nd similar scale plant on large dairy farm in Western Cape Province; construction commenced in Key Benefits of AD to SA: Adds power to Eskom national grid; Moves country towards its renewable power targets; Moves country towards more sustainable waste management (including diversion of biodegradable waste away from landfill disposal); Provides employment in rural areas of the country. Potential Constraints / Challenges Process water availability; Bio-security; Limited current end use for surplus process CHP heat; SA planned programme of nuclear build (long-term). 39

40 The Role of Anaerobic Digestion Technology in Treating Organic Waste UK Experience Presentation to GreenCape Networking event, 23 rd August 2016 Andrew Street Director, SLR Consulting 40