Biomass Cofiring Potential and Experiences in The Netherlands

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Biomass Cofiring Potential andExperiences in The
Netherlands

• René van Ree, Rob Korbee, Theo de Lange,
• Simon Eenkhoorn, Bas Groenendaal
• Netherlands Energy Research Foundation ECN
• Biomass Systems
• International AFB-net Cofiring Workshop
• Grenoble, France, 14-15 September 2000

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CONTENTS

• Dutch renewable energy policy -gt contribution of
  biomass
• Available coal and natural gas fired power plants
• Status current cofiring projects
• Advanced co-firing concepts
• Technical, environmental, and economic
  constraints
• Discussion/conclusions
• ECNs co-firing activities
• Acknowledgement

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Dutch Renewable Energy PolicyContribution of
Biomass
Summer 2000 policy agreement government and

• 10 renewable energy in 2020 (288 PJth,a.f.f.u.)
• Biomass contribution 26

power production companies 6 Mt
CO2-reduction in 2010 -gt 3
Mt by cofiring biomass in coal fired power plants
-gt 20 cofiring
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ECNs Cofiring Activities (1)

• System Assessments
• - steady-state integral thermodynamic system
  analysis
• -gt overall mass and energy balances
• -gt net electrical system efficiencies LHV
• - technical system assessments
• -gt system bottle-necks -gt de-bottle-necking
• - environmental system assessments (incl. LCAs)
• -gt gaseous, liquid, solid system emissions
• - applicable air/water emission constraints
• - commercial applicability of solid waste
  streams (ashes, gypsum)
• - financial-economic system assessments
• -gt specific investment costs Euro/kWe
• -gt investment decision criteria (POT, NPV, ROI)
• -gt costs of avoided CO2-emissions
• -gt biomass fuel costs versus power production
  costs
• incl. applicable subsidies, fiscal regulations
  

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ECNs Cofiring Activities (2)

• Experimental work
• - Thermal conversion (gasification, pyrolysis,
  combustion) of biomass/waste streams
• fuel gas/syngas/flue gas compositions/contaminant
  s
• slagging/fouling behaviour
• - Fuel gas/syngas clean-up/conditioning
  technologies for application of biomass-derived
  gas in downstream equipment
• particles, tars, HCl, H2S, NH3, alkali-metals,
  H2/CO-ratio, ...
• - Bottom-ash and fly-ash characterisation
• the influence of biomass-derived contaminants on
  the quality of these ash fractions and on their
  commercial applicability
• For the experimental work ECN owns a large
  variety
• of lab-scale and bench-scale facilities
• (see conference proceedings)

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Acknowledgement

• The work presented has been performed in the
  framework
• of the in-house RDD-programme ENergy Generation
  In the
• Natural Environment (ENGINE) of ECN
• and was co-funded by
• the Dutch Agency for Energy and the Environment
• (NOVEM)

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Coal Fired Power Plantsin The Netherlands
EPON Electra-Bel (Belgium) EPZ ESSENT
(Netherlands) EZH Preu?en-Elekra (Germany) UNA
Reliant Energy (U.S.A.)
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Natural Gas Fired Installations inThe Netherlands

• Natural gas fired boilers mainly for industrial
  heat production
• more than 900 installations, overall capacity gt
  4600 MWth
• Natural gas fired gas turbine installations for
  CHP production
• more than xxxx installations, overall capacity gt
  4325 MWe
• - power production gas turbines integrated with
  a condensing steam turbine (low
  heat/power-ratio) -gt overall capacity gt 6000 MWe
• - gt 60 built after 1990 -gt dry low-NOx
  combustion chamber
• - lt 40 built before 1990 -gt water/steam
  injection facilities

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Current Cofiring Activitiesin The Netherlands
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Short-term Additional CofiringActivities in The
Netherlands (1)

• EPON
• Cofiring percentage of the Gelderland-13 power
  plant 3 -gt 10 (relatively clean fuels), by 1)
  expanding the current indirect cofiring capacity,
  2) direct cofiring, 3) upstream gasification
  (without add. gas clean-up).
• Cofiring of sewage sludge/high calorific waste
  streams in the gas-fired Eems power plant (1675
  MWe). Technology upstream gasification with a
  very extensive fuel gas clean-up system. Maximum
  cofiring capacity 100 MWth (3 total energetic
  natural gas input).
• EPZ
• Direct cofiring of 6-12 kt/yr sewage sludge in
  Borssele-12 power plant.
• Co-firing capacity expansion in all their coal
  fired power plants. Technologies direct cofiring
  and upstream gasification (and pyrolysis?)

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Short-term Additional CofiringActivities in The
Netherlands (2)

• EZH
• Increasing the quality of the Biomass pellets
  that are currently being cofired (5) in the
  Maasvlakte power plant by potentially integrating
  an additional fuel drying process.
• Direct cofiring of 40 kt/yr poultry litter (4)
  planned.
• UNA
• Direct cofiring of 75 kt/yr sewage sludge (3) in
  the Hemweg power plant planned.
• Potentially two vacuum pyrolysis units (Pyrovac)
  for cofiring purposes planned. Capacity 120
  kt/yr biomass.
• Demkolec
• Direct and indirect cofiring of biomass and waste
  streams in the Buggenum coal
  fired IGCC plant (253 MWe). Plant for sale.
  Future activities depending
  on new plant owner.

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Advanced Future Cofiring ConceptsECN study
co-funded by NOVEM

• To meet Policy Agreement current 0 - 5 -gt 20
  cofiring in coal fired power plants
  (CO2-emissions gas fired plants). Longer-term gt
  20
• Which cofiring concepts are available (coal fired
  power plants and natural gas fired CCs)?
• What is their potential?
• - net electrical biomass conversion efficiency
  LHV?
• - necessary additional specific investment costs
  Euro/kWe?
• What are the technical and environmental cofiring
  constraints?
• What is the financial potential of the cofiring
  concepts?
• -gt preferable biomass cofiring concept
  combinations

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Advanced Future Cofiring ConceptsTechnical and
Environmental constraints

• Technical constraints (coal fired power plants)
• Pretreatment section size reduction, quality
  control, dust explosion danger
• Boiler large gas volume, fuel burn-out,
  slagging/fouling behaviour, (HT)
  corrosion/deposition/erosion danger
• Flue gas clean-up capacity ESP, deactivation
  SCR-catalyst, DeSOx-capacity, emission
  constraints concerning heavy metals
• -gt Most of the technical problems have already
  been solved.
• -gt Further (experimental) attention need
• - the slagging and fouling behaviour
• - the (HT) corrosion problems

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Advanced Future Cofiring ConceptsEconomic
Constraints

• Net electrical efficiency biomass LHV,
  specific costs additional investment Euro/kWe,
  operation time hrs/year, specific financial
  criteria for Dutch situation
• -gt price of fuel that can be converted
  economically as function of the profit of the
  produced electricity

Main financial criteria subsidy (EIAVamil) 25
on add. inv. depreciation time 10 year tax
35 Coal price 1,63 Euro/GJth ...
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Advanced Future Cofiring ConceptsTechnical and
Environmental constraints

• Environmental constraints
• EU air emission constraints applicable for
  (large-scale) power plants.
• Commercial applicability of produced solid waste
  streams (fly-ash, gypsum (bottom-ash)).
• ECN-study

Clean biomass fuels (EU) No problem emissions
(particles, NOx, SO2) to the air
expected. Contaminated biomass fuels (EU) a
variety of components are critical.
Contaminated fuel cofiring -gt heavy metals to
solids -gt critical? Clean fuel cofiring -gt no
critical influence on quality expected
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Advanced Future Cofiring ConceptsCofiring
concepts and their potential
Base-case coal fired combustion plant - 600
MWe - Net eff. 40 LHV - 6000 hrs/yr
10 / 40 cofiring
Base-case natural gas fired CC - 335 MWe - Net
eff. 55LHV - 6000 hrs/yr 5, 10, 20 cofiring
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Discussion/conclusions (1)

• Policy agreement government - power production
  companies concerning CO2-emission reduction coal
  fired power plants -gt 20 cofiring in 2010
• Current cofiring activities mainly direct
  cofiring in coal fired power plants (lt 5 of
  total energetic plant input).
• Six main concepts have been identified to
  increase the cofiring capacity of coal fired
  power plants further direct cofiring, indirect
  cofiring, separate gasification, separate
  pyrolysis, separate HTU and separate combustion
  with steam-side integration.
• Preferable concepts for clean biomass fuels (EU)
  direct cofiring, separate gasification without
  fgcu.
• Preferable concepts for contaminated biomass
  fuels separate gasification with fgcu and slow
  pyrolysis with pgcu. A cheaper alternative could
  probably be mixing these fuels with clean fuels.

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Discussion/conclusions (2)

• For cofiring in natural gas fired CCs, the
  biomass has to be gasified upstream, after which
  the fuel gas has to be cleaned extensively,
  before the gas is mixed with natural gas to be
  combusted in the CC.
• The main technical constraints that have to be
  solved (experimentally) for cofiring of biomass
  in coal fired power plants are fouling/slagging
  and (hot) corrosion.
• The main technical constraint that has to be
  solved for biomass cofiring in natural gas fired
  CCs is to get a better insight in the maximum
  amount of LCG that can be burned in relatively
  new gas turbines with dry low-NOx burners.
• For clean biomass cofiring no problems are
  expected concerning applicable EU air emission
  constraints and the quality of produced solid
  waste streams.
• For contaminated biomass fuels both aspects need
  further research.