Biomass technologies

Transcription

1 Biomass technologies Micro Generation Workshop Presentation Alan Draper

2 What is it? Biological material derived from living, or recently living organisms In the context of energy this often means plant based material But can equally apply to both animal and vegetable derived material Many different forms can be burned or digested to produce energy So it is a very versatile material that can be used to produce heat (for space and water heating) electricity combination of heat and power (electricity) The UK has some of the largest examples of the use of Biomass to generate electricity in Europe Elean straw power station Cambridge

3 What is it? Wood and straw Energy crops - willow and poplar grown on short rotation coppice Miscanthus Chicken litter, animal slurry Some forms of municipal and industrial waste Forestry and agricultural wastes Industrial Wastes, e.g. manufacturing co-product

4 Why is it a renewable fuel? A carbon neutral process as the CO 2 released during burning is balanced by that absorbed during the growing cycle Can be carbon negative when combined with CCS technology (carbon collection and storage) Has both environmental and economic advantages Can contribute to waste management by harnessing energy from products that are often disposed of at landfill sites It is most cost effective when a local fuel source is used Resulting in local investment and employment Minimises transport miles

5 Fuels European Renewable Electricity Directive Biomass shall mean the biodegradable fraction of products, waste and residues from agriculture (including vegetable and animal substances). Forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste Fuels can either be pure biomass or contain a biomass fraction Pelletised fuels Bio-fuels, e.g. manufactured fuels from crops, waste oils, coproducts Domestic and commercial waste,.e.g. MSW and associated refuse derived fuels (RDF)

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7 Fuel Costs Costs vary significantly depending on the fuel type: MSW and its derived fuels (gate fee) Construction or Demolition wastes Recycled wood waste Forestry and agricultural wastes Wood Chips Pelletised Fuels Energy Crops Increasing Cost 20 80/tonne nom value (or gate fee) per tonne per tonne 40+ per tonne per tonne 60+ per tonne

8 - Wood as a Fuel Automatic wood heating is now a major industry in most Northern European Countries Number of installations 35,000 30,000 25,000 20,000 15,000 10,000 5,000 Biomass Heating in Austria Displacing fossil fuels Creating local jobs Bringing woodlands back into management Large scale UK boiler installations - probably less than

9 Wood Chip vs Wood Pellet Characteristics of Wood Chip Local fuel, helps woodland management Low cost fuel Low bulk density large storage required Characteristics of Wood Pellets Standard product with low moisture content High density important for storage Small and uniform size Ideal for small automatic heating systems

10 - Supply of Heat Delivery from heat only or a CHP unit can be made in a number of ways: Hot water 50 o C 120 o C Steam 1 bar bar pressure Other thermal fluids (oil) thermal oil 220 o C 280 o C Air 50 o C +400 o C Available directly to the process, e.g. Steam produced used directly Or provided indirectly through a heat exchanger e.g. steam to heat air for a drying process.

11 Considerations Space for plant Space for storage facility for fuel Security of supply Heat and power demand profiles heat loads Potential for off-site export of power and heat Connections to existing infrastructure linking into site heat network and power supply Operation internal or external Impact on supply agreements from existing suppliers

12 Schematic diagram of a Combined Heat and Power (CHP) plant, using steam cycle Furnace/gasifier/pyrolyser Turbine Generator Ash handling system Heat distribution system HEx & Heat use monitoring Smallest units kwe have a footprint of c. 4m x 6m Biomass heat output is ~3x electricity i.e. 1 MW electrical unit yields 3 MW of heat.

13 Boilers - Automatic Fully automated with thermostatic control High efficiencies 80-94% Price of wood chip fuel much cheaper than heating oil MAIN FEATURES Auger feeding the woodchips Fan supplying combustion air Fire box Boiler Control unit

14 By-Products Emissions to Air The properties of the flue gases (combustion products) will depend on the fuel and technology choice Regulation governs emission limits -dependent on the scale and the classification of the facility i.e. is it waste etc For waste materials (especially those covered by the Waste Incineration Directive (WID)) can be extremely demanding and costly Use of clean materials will have far less demanding requirements Solid Residues Burning energy crops and clean biomass will produce ash, which can be sold as a fertiliser (subject to analysis) Ash from waste materials will still be waste and needs to be managed accordingly, e.g. disposal/cover for landfill

15 Stand alone room heaters generally cost around 3,000 installed. Savings will depend on how much they are used and which fuel you are replacing. The cost for boilers varies depending on the system choice; a typical 15kW (average size required for a three-bedroom semi detached house) pellet boiler would cost around 5,500-12,000 installed, including the cost of the flue and commissioning. A manual log feed system of the same size would be slightly cheaper. A biomass powered boiler could save you around 200 a year in energy bills and around 8 tonnes of C0 2 per year. Unlike other forms of renewable energy, biomass systems require you to pay for the fuel. Fuel costs generally depend on the distance from your supplier and whether you can buy in large quantities.

16 Customer Expectations Some customers are prepared to do some tasks, others none. Approaching same degree of comfort and convenience as with a fossil fuel. Totally automatic Thermostatic/timer control Economical to run (low cost fuel and high efficiency) Be reliable Non polluting (no smoke)

17 - Economics of Heating Fuels 3.4 p/kwh a) Wood chips at 30/t at 25% mc b) Wood chips at 40/t at 25% mc c) Wood chips at 50/t at 25% mc d) Wood 80/tonne e) Heating oil at 15p/litre f) Heating oil at 20p/litre g) Heating oil at 25p/litre h) LPG Low i) LPG High j) Average domestic gas tariff Wood Chips Wood Chips Wood Chips Wood Pellets Oil Oil Oil LPG LPG Mains Gas Night Storage k) Using off-peak electricity

18 The Costs Technology Minimum economic scale Capex range ( /kw) Examples in UK Biomass Heating c. 1 kw > 3,000 Biomass Electricity/CHP (combustion) From 100 KWe? 1,700 3,500 c. 20 Biomass Electricity/CHP (advanced conversion) 5 MW? 2,500 5,500 2 Anaerobic Digestion (CHP) 100 kw 2,000 3, Biomass micro CHP 100 kw 2,500-3,500 < 5

19 Production of Wood Chip Cost of chip production depends on: Scale of operation Type of wood available

20 Wood chip delivery

21 Wood chip delivery Large Bags Pneumatic System Wood chip fuel supply must be kept local Delivery of wood chip into fuel store is critical

22 Case study: Chip fired boiler 70kW chip system, Mid Devon, heating offices, private house, workshops and swimming pool

23 Case Study: Kielder District Heat Scale: 300 kw biomass heat, commissioned June 2004 Fuel: Woodchip locally sourced from the Forestry Commission Technology: Kob 300kW, fully automatic, woodfuelled boiler was installed which uses tonnes of wood annually saving ~57 tonnes of CO 2 per year Design: Heat and hot water provision for a visitor centre, six 3-bedroom houses, workshops, primary school and youth hostel. Centralised heat plant with super insulated distribution pipes Capital Cost: 650,000 Contract: Community owned energy service company, customers are billed by units of heat consumed

24 Case Study: Worcestershire County Hall Scale: 700kW biomass heat Fuel: Woodchip locally sourced Installed: May 2002 Technology: Fully automatic, wood-fuelled boiler installed using 600 tonnes pa Design: Meets approximately 75% of the building heat load Capital Cost: 150k Contract: 10 year operational contract includes maintenance

25 Case Study: Kirk Balk School, Barnsley Scale: 2 x 732kW heating units Fuel: Wood pellets Details: Two underfeed stokers on two of the three Hartley and Sugdenware converted to fully modulating units Benefits: The use of wood fuel improved combustion conditions and efficiency was raised to 86%, higher than a similar size high efficiency gas boiler available at the time Key issue: Biomass supply price must be competitive with coal

26 Project: Biomass CHP plant Germany Scale: 5.3MWe max, 3.5MWth for district heating Fuel: Waste wood from forestry operations Technology: The plant comprises a Wärtsilä BioPower 5 CEX standardised power plant. The combustion technology is based on the patented Wärtsilä rotating grate. Timing: Construction approximately 1 year Cost: Est. 10,000,000

27 - Summary Benefits Adaptable / Flexible Carbon neutral Carbon negative when combined with CCS Minimal Maintenance Efficient Main growth area for the near future Issues Supply chain is still fragile Continuous fuel costs Quality and consistency of fuel is critical - moisture Large storage space required Growing acreage

28 Key Considerations for Projects What are you trying to achieve? Fuel supply and price main operating cost Specification of proposed fuels, i.e. is it waste? Security of fuel supplies Planning and permitting requirements Financing options third party or internal capital? Management of facility third party contract?

29 Thank You Questions

30 Maturity of the Technology

31 Biomass Woody b Non-woo produ These are the CO2 f next grow Used in ro stoves a Used for

32 Intro to renewable possibilities Cartoon ~ clipart? All Energy comes from the sun