A technology overview for energy from biomass....
Biomass technology overview
Bhaskar Deol
[email protected] +44 (0) 753 667 0734
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Agenda 1. Biomass as a source of energy 2. Sources of biomass 3. Major conversion technologies o
Direct combustion
o
Gasification
o
Pyrolysis
o
Anaerobic digestion
o
Co-firing
o
Major technologies overview
4. Bioelectricity in Europe
5. Economics of biomass 6. SWOT 7. Summary
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What is biomass What is biomass Biomass is a renewable organic biological material and includes materials like wood, grasses, energy crops, residues from agriculture and forestry, organic components of municipal and industrial wastes, and fumes from landfills What is biomass energy Biomass energy is energy produced from the direct burning of biomass, or converting it into gaseous or liquid fuels that burn more efficiently, to generate electricity or heat for industrial purposes
Source: EIA 13 June 2010
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Biomass as a source of energy Biomass pyramid
Comments
•Current total energy use is ~500 EJ/year, biomass is 10% of total energy usage
•Primary demand in 2050 is forecasted between 600-1000 EJ •Technical potential for biomass in 2050 is 1500 EJ •By 2050, between 250-500 EJ can be sustainably met using biomass • • • • •
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Agricultural and forestry residues~ 100 EJ Surplus forest production (over current harvest) ~80 EJ Energy crops (areas without soil degradation / water scarcity) ~120 EJ Energy crops (areas with soil degradation / water scarcity) ~70 EJ Additional potential from agricultural productivity increase ~140 EJ
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Biomass to energy conversion paths Resources
Conversion
Solid biomass -Forestry residue -Short rotational forestry -Agricultural residue -Energy crops
Products
Output
1 Incineration
Heat
2 Gasification
Fuel gas Heat / CHP
Waste -Municipal -Industrial
3 Pyrolysis
Wet biomass -Organic waste -Manure -Sewage, sludge
Anaerobic Digestion
Cofiring
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Electricity Bio oil / biofuels
Biogas / Landfill gas
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Direct biomass combustion Biomass combustion schematic
Fixed bed Grate furnace
Bubbling fluidized bed
Circulating fluidized bed
Fixed bed • Biomass burns on a grate that travels thru the furnace, towards ash removal • Reliable technology with low investment costs • Limited range of biomass fuel types
Dust firing
1. Solid biomass is prepared (dried, baled, chipped, formed into pellets or briquettes) 2. Solid biomass is burned in boilers 3. Ash is removed from the system either by a grate or as a suspension in air, depending on design
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1 Incineration
Fluidized bed (bubbling / circulating) • Fuel burns in a constantly mixing suspension of inert bed material • Very effective mixing results in wide range of usable fuel types, if uniform particle size can be maintained • High capex and opex is required Dust combustion • Small sized particles (e.g. sawdust, fine wood) is burned as a suspension in air in a combustion chamber
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Biomass gasification Gasification schematic
Gasification
1. Biomass feedstock is converted into gaseous fuel by partial oxidation under insufficient supply of air and high temperature (~900 oC) 2. Products are H2, CO2, CH4, H20 inorganic residues & oil-tar, with calorific value ~ 10% to 50% of that of natural gas 3. This gas is burned in boilers; or after cleanup to remove tars in engines or gas turbines; or reformed to produce methanol or Hydrogen Fixed bed gasifier
Updraft fixed bed (countercurrent)
Downdraft Fixed bed (cocurrent)
•
In an updraft gasifier, air and biomass flow in counterflow, resulting in a high tar content along with the gaseous product
•
In a downdraft gasifier, temperature of 1000 oC results in cracking of some of the tars and results in gas with lower tar content
Fluidized bed gasifier
Bubbling fluidized bed 13 June 2010
•
In an FB gasifier, drying, pyrolysis and gasification occurs in a fluidized mixture of inert bed material
•
Various types of fluidized beds have been tested (bubbling, circulating, etc)
•
These have a wide range of fuel types and can handle wet biomass but fuel needs to be treated to roughly 50mm size or smaller
•
Recent developments couple fluidized beds with a combined cycle steam turbine (IGCC), which can achieve high efficiencies (~50%)
Circulating fluidized bed Bhaskar Deol
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Biomass pyrolysis Pyrolysis schematic
Pyrolysis
• Pyrolysis is very similar to gasification, but takes place at a lower temperature • Any biomass can be considered for pyrolysis, but most work has been done on wood due to its consistency • Biomass breaks down at 500 – 700 oC to yield partial products of char, a mixture of gases and the majority product bio-oil
Pyrolysis modes and products
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• Bio-oil produced is upgraded and used in boilers, engines or gas turbines for electricity / CHP
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Anaerobic Digestion
Anaerobic digestion Anaerobic digestion schematic
• Biomass matter is fed into a tank and converted into a gas in absence of oxygen
• Solid liquid residues from the process are used as fertilizers • Anaerobic digestion can handle very wet feedstocks, e.g. sewage sludge, agricultural and industrial organic wastes, animal by-products and organic municipal solid wastes • Biogas contains 60-70% CH4 and remaining CO2
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4
5
Co-firing Direct co-firing
Co-firing
Direct co-firing •
Appropriately prepared biomass is fed directly into the coal furnace
•
Biomass can be fed into the coal burners or dedicated biomass burners
Indirect co-firing Indirect co-firing
•
Biomass is gasified (or pyrolyzed) separately to produce a fuel gas, which is burned in the coal fired furnace
•
More expensive than direct co-firing and can currently only use wood fuel
Parallel co-firing
Parallel co-firing
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•
Biomass is combusted in a separate boiler and the steam is fed into the coal fired station
•
Higher temperate / pressure conditions result in increased efficiency
•
Need for a parallel biomass combustion leads to higher costs
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Conversion technologies overview Technology
Direct combustion
Cofiring
Gasification
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Plant Size
Comments • Low capex • Limited range of biomass types
Fixed bed
Biomass burns in a layer on a grate which moves to transport the fuel to ash removal
Fluidized bed
Fuel burns in a constantly mixing suspension of hot, inert, granular bed material (e.g. silica sand)
> 20 MW
• Wide range of fuels • Need uniform size • Large Capex / Opex
Dust firing
Small particles (e.g. sawdust or fine wood shavings) burned with air in a combustion chamber
2 - 8 MW
• High unit costs • Low plant efficiency
Direct co-firing
Prepared biomass directly fed into the furnace
50-700 MW
Indirect-co firing
Separate gasification of biomass in a fluidized bed, resulting 15-100 MW gas is burned in the coal fired boiler furnace
• • • • •
Parallel co-firing
Biomass combusted in a separate boiler and resulting steam upgraded to that coming from the coal plant
Fixed bed
Conversion of biomass to gaseous fuel by partial oxidation and elevated temperatures
Small / Decentralized
Fluidized bed (FB)
Conversion of biomass to gaseous fuel in a hot, fluidized mixture with inert bed material and air. Latest developments try to combine FB with steam turbines (Integrated gasification combined cycle)
Bubbling: 15-80MW Circulating: 40-100MW
Fast pyrolysis
Thermal decomposition of biomass in the absence of oxygen, resulting in char, bio-oil and combustible gases
1-stage
Liquid biomass is fed into a reactor where it is converted into biogas and organic material
2-stage
Hydrolysis is carried out as a separate stage in AD, resulting 10kW – in more stable conditions allowing higher solid content in 10 MW the digester
Pyrolysis
Anaerobic Digestion
Description
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Range up to 40% biomass Typical commercial 3-5% Typically low investment Lowered SOx and NOx Indirect and parallel co-firing require increasing amounts of capital investment
• FB gasifiers have high throughput and can handle various types and condition of fuel (e.g. wet biomass) • Pyrolysis concentrates volatile components of oil into a transportable oil
10kW – 10MW • Separating stages allows higher solid concentration and more stable process compared to 1-stage
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Development status of major technologies Research & Development Biomass Densification
Demonstration Torrefaction
Early Commercial
Pyrolysis
Pelletization
HTU1
Biomass to heat
Gasification
Combustion (boilers and stoves)
ORC2 Stirling engine
Combustion
Gasification IGFC3
IGCC4 IGGT5
Co-firing
Steam cycle
Gasification + Steam cycle
Indirect co-firing
Anaerobic Microbial Digestion fuel cells
upgrading; 2 Organic rankine cycle;
Parallel co-firing Biogas upgrading
Biomass densification 1 Hydrothermal
Commercial
Biomass to heat 3,4,5
2-stage AD
Direct co-firing 1-stage AD
Biomass to power CHP
Integrated gasification fuel cell (FC) / combined cycle (CC) / gas turbine (GT)
Source: IEA Bioenergy publication 13 June 2010
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Bioelectricity in Europe: markets Bubble size = Bioelectricity MW installed, 2007 Estimate
US, 0.6% China, 0.6% India, 0.6%
T=624 Bio =2
Total =966 GW Bioelect. = 5 GW
Source: Eurostat, DOE, internet 13 June 2010
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Bioelectricity in Europe: sources 5
Municipal Solid Waste Wood/Wood Waste
2007 Installed capacity, GW
4
Biogas
3
2
1
0
Belgium
Denmark
Spain
Netherlands
France
Czech Republic
UK
Finland
Austria
Sweden
Italy
Germany
Source: Eurostat 13 June 2010
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Economics of bioelectricity: capex Capital cost of biomass by type
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Economics of bioelectricity: levelized
Levelized cost of energy $/MWh
Source: Lazard analysis 13 June 2010
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Economics of bioelectricity: future outlook
Comments • Direct combustion is cost competitive and dispatchable, hence can act as a base load source of power • Co-firing, gasification and pyrolysis are broadly competitive to other renewable technologies and become attractive when incentivized • Most technological developments likely on gasification + combined cycle. This would also achieve highest overall efficiency
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Feed-in tariffs for biomass in Europe Germany Biomass 2007 Type
FIT (c€)
Germany Waste/Sewage 2007 Type
FIT (c€)
Netherlands 2007 Type
FIT (c€)
France 2009 Type
FIT (c€)
UK 2009 (Proposed) Type
FIT (p)
10.99
0-500 kW
7.33
Mixed
2.9
Vegetable biomass
4.9
Anaerobic electricity
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151-500 kW
9.46
501 kW 5 MW
6.35
50 MW
20 years
10 years
15 years • Anaerobic digestion, gasification, pyrolysis, dedicated energy crops, and biomass with CHP fall under emerging technologies category and attract 2ROC/MWh. • 1 ROC = £ 45.52 on 10/2009
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SWOT analysis for biomass Strengths
Weaknesses
• Potentially an abundant resource • Electricity from biomass and waste using is well established and economically viable • Biomass can provide baseload capacity and is dispatchable, unlike other renewable sources
Opportunities
High costs and low conversion efficiency Low energy density Fuel supply risks Difficulty in obtaining PPAs for small project developers • No market for fuels, fragmented suppliers • Some technologies are sensitive to variety and physical properties of feedstock
Threats / Barriers
• Many biomass technologies are commercially viable at small and large scales • Increasing focus on bio energy would result in increasing production of high-energy density, purpose grown feedstock • Favourable feed-in tariffs continue to support small scale installations of biomass
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• • • •
• Financing • Perception of project complexity and risk makes financing difficult • Few financiers with biomass experience
• Competition from other uses of biomass, such as biofuels, food, etc. • Competition from other uses of land • Public perception about emissions • Long process for obtaining plant permissions
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United Kingdom
US and Canada
Major biomass projects Company Name/Subsidiary
Capacity
Feedstock
Location
Status
Greenhunter Energy, Inc.
14MW
Wood waste
Florida
Renovating (2009)
18.5MW
Cow manure/ Wood waste
California
In development (2009)
Renegy Holdings
24MW
Paper Mill Sludge / Wood Waste
Arizona
In operation
Covant a Holding Co.
1,272 MW Total -35 Plants Waste to Energy
U.S./Europe
Canadian Hydro Developers
76MW Total -4 Plants 15MW Total -4 Plants 25MW
Wood waste/ Ag. Residues Landfill Gas Wood waste
U.S. US Alberta
In operation In operation In operation In operation
Boralex Power Income Fund
63MW
Wood waste
Quebec
Temporarily shut down
Macquarie Power & Infrastructure I.F.
28MW 31MW
Wood waste Wood waste
Alberta Quebec
Pristine Power
65MW
Wood waste
B.C.
In operation In operation In development
West Fraser Timber
30MW (50% of 60MW)
Wood waste
B.C.
In development
Run of River Power Inc.
24MW (80% of 30MW)
Wood waste
B.C.
In development
30MW (50% of 60MW)
Wood waste
B.C.
Installer
Technology
Eco2
Wood
Western Log Group / Western Bio Energy Ltd 10MW
Wood
In development Longlands Lane, Wales In operation
Fibropower Ltd
12.7MW
Animal waste (Poultry/horse/feathers)
England (Eye Airfield)
In operation
Aalborg Boilers A/S
SembCorp
30MW
Wood
England (Wilton 10)
In operation
SembCorp
EPR
13.5MW
Animal waste (Poultry)
England (Glanford)
In operation
Foster Wheeler Direct combustion, Energy Ltd Grate
38MW
Straw
In operation
FLS Miljo
38.5MW
Animal waste (Poultry)
In operation
Taylor Woodrow
E.on
44MW
Wood (Sawmill products)
In operation
E.on
Eco2
40MW 40MW
Straw Straw
England (Ely Power Station) England (Thetford) Scotland (Stevens Croft) England (Brigg REP) England (Sleaford)
In development In development
Prenergy
350MW
Wood pellets
Wales (Port Talbot)
Eco2 Eco2 Sinclair Knight Merz
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In development (2011)
Direct combustion, Vibrating Grate Direct combustion, Grate
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Europe
Major biomass projects (contd.) Company Name/Subsidiary
Capacity
Feedstock
Location
Status
Installer
Amel (operated by Renogen)
5.3MW
Wood residue
Belgium
In operation
BMC Moerdijk
36MW
Animal waste (Poultry)
Netherlands
In operation
Del-Nyirsegi (DBM Zrt)
20MW
Wood
Hungary
In operation
Wartsila Austrian energy, Siemens EGI Engineering
Mortagua (Enenova) Pecs (Pannon Power) Rodao (Altri SGPS SA) Sanguesa (EHN Group)
9MW 65MW 11MW 30MW
Wood Wood, Natural gas Wood, agricultural waste Straw
Portugal Hungary Portugal Spain
In operation In operation In operation In operation
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Technology
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UK 2020 renewables forecast
Source: DOEACC 13 June 2010
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Summary • Share of biomass as an energy source is going to increase over the next several years • Multiple conversion technologies exist or are being developed efficiently utilize or to increase the viability of this abundant resource • Biomass is one of the few renewable sources that can provide base load power and can be used on small to large scale installations
Technology Implications
Project Implications
• Biomass is a potentially large market for cleantech • Scope for potential investments in companies developing technology for gasification, gasification combined cycle, 2-stage anaerobic digestion and parallel co-firing
• Coupled with carbon credits and FIT’s, some sources of biomass attract lucrative project returns • Further analysis of project returns across biomass sectors needed
• Scope for investment in project developers or interesting business models based on biomass
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Backup slides
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Appendix 1: Energy value / Dispatchability Average heat energy content of fuels
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Capacity factors for renewables
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Appendix 2: Integrated Gasification Combined Cycle
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Appendix 3: Gasification products
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Appendix 4: Detailed biomass conversion chart
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