Biomass CHP – best practiceConclusions and recommendations

Anders Evald, Janet Witt, Kati VeijonenHarrie Knoef, Johan Vinterbäck, Elvira Lutter

Vienna 9 March 2006

Project aims

• Promote biomass CHP in Europe and highlight plants with the best operation

• Provide e.g. authorities and future plant owners with information about typical plant performance and about best available technologies.

• Enable benchmarking, identify the improvement potential of the existing European CHP plants

• Replicate best practices• Challenge: collect reliable data

Different technolgies covered

• 19 biogas and landfill gas plants• 4 gasification plants• 10 CFB (circulating fluidized bed) plants• 11 BFB (bubbling fluidized bed) plants• 15 grate-fired steam boiler plants using

uncontaminated biomass• 8 grate-fired steam boiler plants using

municipal solid• waste (MSW) as a fuel• 1 dust fired steam boiler plant

Fuels covered

• Solid biomass– Forest fuels– Forest industry by-products such as bark, sawdust

etc.– Wood pellets– Agricultural residues such as straw, husk etc.– Municipal solid waste– Landfill gas– Manure etc. for biogas plants

• Fossil fuels– Heavy fuel oil– Natural gas– Coal

Key performance indicators

• availability• utilisation period• total efficiency• fuel input: biofuels vs. fossil fuels• nominal efficiency vs. operational efficiency• own power consumption• total efficiency on monthly basis

Gasification plants

Utilization factor: the extent, to which installed power is utilisedAvailability factor: the extent, to which the plant is available for operation

Availability and utilisation factor

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Nominal efficiency and operational efficiency

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Total efficiency of individual plant over 24 month

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Gratefired boiler plants

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Ranked to increasing capacity

Annual energy production and operational efficiency

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heat production: 606 GWh/a

Total efficiency of individual plants over 24 month

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Cross technology comparison

Min./max. net power output of participating plants for six conversion technologies

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AverageMax. value: 200 MWel

Plant size

Min./max. electric efficiency of participating plants for six conversion technologies

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Electric efficiency

Min./max. total efficiency of participating plants for six conversion technologies

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Total efficiency

Min./max. electric utilisation factor of participating plants for six conversion technologies

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Min./max. availability of participating plants for six conversion technologies

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CFB plants BFB plants grate firedboiler plants

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Availability

Conclusions and recommendations

1. Bigger is better– Higher efficicency– Lower own consumption– Better availability– Lower specific investment– But constrained by heat marked, and not

necessarily true for biogas plants

Capacity and utilization

• Plants are bigger than simply justified by the heat market– High electricity price– Optimizing tariff income– Heat accumulator

• Plants built for the future• Plant nominal capacity is too optimistic – very few plant

perform anywhere near their anticipated (nominal) efficiency in practical operation

• Economic optimization– Not too small– Not too big

• Low utilization = poor payback on invested capital

CHP or not CHP

• Many plants are not 100% dependent on heat market (combined heat and power only as a fraction)

• German biogas plants produce very little heat, and they don’t meassure it

• Premium price for electricity not allways require full combined production– Incentive for RE, but not for the most efficient RE

• Large plants (MSW) cannot connect enough heat demand

Balancing heat and power

• Energy efficiency: electricity is the premium product; heat is a by-product

• Valid also money-wise• But not allways: nordic heat markets show

high value for heat• Industrial facilities might see steam as the

main product and electricity as a byproduct

Choosing the right technology

• Large difference in electric efficiency• Low electric efficiency is compensated by

more heat• Heat market set the framework• Steam cycles: go for high steam data• Retrofitting old equipment to improve

efficiency and reduce own consumption

Industrial systems

• A more fragile heat market• Industries change• Operated according to steam demand – less

power and low utilization

Reducing own consumption

• Big difference depending on choice of technology

• Option for improvement in old plants• Low efficiency lead to high own concumption

Operational problems

• New challenges for plant operators• Fuel quality problems (feed systems, moisture

content, flue gas fans etc.)• Sintering bed material• Fouling heat transfer surfaces

– Decrease efficiency and high temperature corrosion

• Result: lower efficiencies, higher maintenance

• Exchange experience!

Some concluding remarks [1]

• Technology implemented must be mature – Proven prototype models– Long-term duration tests

• Adequate infrastructure– Local manufacturing capacity– After-sale service– Training facilities– Sustainable feedstock supply

• Motivated & skilled labor – Operators, Management– Incentives

Some concluding remarks [2]

• Information & knowledge exchange – Performance, limitations, opportunities– Evaluation with competing options– Set-up monitoring program of successes in India, China

• Clear regulations– Permitting procedures– Emission according to “ALARP”– Health, Safety & Environment

• Sale of electricity and heat– Any legal obstacle should be removed– Long-term fixed price is prerequisite

Some concluding remarks [3]

• Product quality must meet client specifications– Technical performance– Financial/economic performance– Operational performance– Gaining confidence

• Certification – stimulation– product must meet defined quality standards

• Scale-up, demonstration, replication, optimization– Economy of numbers (instead of economy of scale)– Reduced capital costs– Improvement from learning by doing

Some concluding remarks [4]

Do not repeat the mistakes from the past– learning by doing and not by a scientific approach

(cooperation is prefered)– too optimistic approach of the economics, efficiency and

availability, projections: 7000 hrs of operation in 1st year– no optimal cooperation of the ownership-consortium and

conflicting interests (who is responsible for what). • Manufacturer versus plant owner• Plant owner/technology supplier versus permitting

authority

Health, Safety & Environment

Powerto Local Grid

Gas Utilization

Gasifier

GasCooling

Exhaust gasto Chimney

Biomass

Agents(air, steam etc.)

Waste Water &

CondensatesCondensates

Flare

GasCleaning

Gas Engine

Waste Water

TreatmentWaste Water

to Canalisation or Disposal

Heatto District Heating

Process Automation

GeneratorHeat

Int. DemandDusts

Gas fired Boilers

Powerto Local Grid

Gas Utilization

Gasifier

GasCooling

Exhaust gasto Chimney

Biomass

Agents(air, steam etc.)

Waste Water &

CondensatesCondensates

Flare

GasCleaning

Gas Engine

Waste Water

TreatmentWaste Water

to Canalisation or Disposal

Heatto District Heating

Process Automation

GeneratorHeat

Int. DemandDusts

Gas fired Boilers

www.gasification-guide.eu

Success stories CHP gasifiers [1]

• More than “5 installed” systems:– Bioneer [district heating]– Co-firing [at power stations]– Biomass engineering, UK– Eqtec, Spain– Xylowatt, BE– Mothermik, DE– Pyroforce, CH– Güssing concept, AT– Volund (DK, DE, Japan, Italy))– India, China (thousands, but unfavourable

emissions)

Success stories [2]

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2002 2003 2004 2005 2006 2007

ho

urs

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era

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gasifierengine

Success stories [3]

Thank you for your attention!

Harrie KnoefBTG biomass technology group BVwww.btgworld.comKnoef@btgworld.comPh: +31-53-4861190