Technologies for Small-Scale Biomass CHP-Plants

Donnerstag, 24. Juli 2003

Seite 1

Biomasse Info-Zentrum

Biomass Information Centre

Technologies for small scale Biomass

CHP-Plants – an actual survey

Risoe, May, 20th 2003

Dr.-Ing. J. Fischer

Biomass Information Centre

Institute for Energy Economics and Rational Use of Energy, IER,

University of Stuttgart

Hessbrühlstr. 49A. , D-70565 Stuttgart, Germany

Tel.: ++49-711/7813909, Fax: ++49-711/7806177

Internet: www.biomasse-info.net

Donnerstag, 24. Juli 2003

Seite 2

Biomasse Info-Zentrum

Biomass Information Centre

EU: Primary Energy Consumption 2001

oil

42%

natural gas

23%

nuclear

13%

wind

hydropower

biomass

coal

14%

EU 15:

Primary Energy

Demand (2001)

63,9 EJ

Donnerstag, 24. Juli 2003

Seite 3

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Biomass Information Centre

Biomass: Maximum Contribution

elgium, Lu

nmark

ermany

Finland

France

reec

reat Britain

Ireland

Italy

ther

lands

ust

ria

ortugal

weden

pain

U-15

Donnerstag, 24. Juli 2003

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Biomass Information Centre

Biogas - fuel cell

Dust engine/-turbine
ORC--process

Hot Gasturbine

Gasification - engine
Gasification - gasturbine

Gasification - fuel cell

Pyrolysis - gasturbine

Vegetable oil- engine
RME-engine

Steamprocess

Bioethanol - engine

Methanol - engine*

Methanol - fuel cell*

Co- Combustion

Biogas

Methan - fuel cell *

* = if biomass is used

Processes f. Electricity

generation

Theoretical
investi-
gations

Laboratory,
testing,of
components

Pilotplant

Demonstration -
plant

Market

Donnerstag, 24. Juli 2003

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Biomass Information Centre

Steam Turbine

Advantages Disadvantages

! Mature, proven technology !

Small steam turbines < 1

offer only limited

efficiencies

! Broad power range

available

! Low efficiency at partial load

! For large installations: high

efficiencies can be

obtained by high steam

temperatures and

pressures

! High specific investment

costs for small turbines

! Separation between

combustion and power

generation enables the use

of ash containing fuels

! For biomass application:

limited super heater

temperature because of risk

of high temperature corrosion

Donnerstag, 24. Juli 2003

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Biomass Information Centre

Steam Engine

Advantages Disadvantages

Suitable for lower power

ranges

! Maximum power output is

limited to about 1.2 MW

Saturated steam can be

used

! High maintenance costs

Very good performance at

partial load

! Electrical efficiency is limited

due to low steam pressures

(< 25 bar)

Steam extraction at various

pressures possible due to

modularity

! Heavy vibration and noise

production

Oil free construction

avoids steam

contamination

Donnerstag, 24. Juli 2003

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Biomass Information Centre

ORC - Process

Advantages Disadvantages

Robust technology

! Relatively high specific

investment costs

Very good controllability and

high degree of automation

! Long term experiences using

biomass still missing

Low maintenance required

! Organic thermal oil is

inflammable and toxic

Very good performance at

partial load

! Due to low pressures ( 10 –20

bar) only limited electrical

efficiency

Low temperature waste heat

can be used

Donnerstag, 24. Juli 2003

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Biomass Information Centre

Stirling - Engine

Advantages Disadvantages

! Engine operates independently

of type of heat source

! If solid biomass is used, relatively

low electrical efficiencies are

achieved

! Low quality demand with respect

to fuel

! no reliable solution for sealing

problems

! Low maintenance demand

because of few moving parts and

“external combustion”

! High specific investment costs

! Formation of emissions like CO

and CH can be avoided due to

external combustion of (bio-) gas

! Heat exchanger is exposed to

extreme wear because of high

temperature strain

! Risk of high temperature corrosion

in ash containing flue gases

Donnerstag, 24. Juli 2003

Seite 16

Biomasse Info-Zentrum

Biomass Information Centre

Costs of Biomass CHP-Plants

2000

4000

6000

8000

10000

12000

14000

€/kW

Biogas CHP

Rapeseed CHP

Gasification, engine

Gasification, turbine

Gasification, fuel cell

Stirling

ORC

Steam turbine/engine

Source: Fichtner, Kaltschmitt, IEA, Heinz, BIZ

Donnerstag, 24. Juli 2003

Seite 17

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Biomass Information Centre

Conclusions

! Biomass may contribute to a large extent to a sustainable

Energy Future in Europe

! Biomass is due to its properties best suited for small scale,

decentralised CHP-Plants

! Limited interest in bioenergy within the last decades leads to a

lack of efficient technologies for this purpose

! Increased research work, a closer cooperation among

research institutes and industry and a better information
transfer are essential to activate the enormous potential of
bioenergy

Document Outline