Biocellus - Highly efficient SOFC systems with indirect ...€¦ · Biocellus - Highly efficient SOFC systems with indirect gasification International workshop on "Bio-energy workshop

BioCellus • Biomass Fuel Cell Utility System • Contract No: 502759

Biocellus - Highly efficient SOFC systems with indirect gasification

International workshop on "Bio-energy workshop EU-Russia" 7-8th of October 2004, All-Russian Thermal Engineering Institute (VTI), Moscow

J. Karl, Lehrstuhl für Thermische KraftanlagenTechnische Universität München

Influence of the system integration on the economics of fuel cell systems

100 %

34 kW

51 %

45 % 900 °C

79 %

Brennkammer

134 %

chemisch gebundene Energie 122 %

fühlbare Wärme 12%

800 °C

EconomicsEconomics

ThermodynamicsThermodynamics

SOFC coolingSOFC cooling

Biocellus Biocellus

ConclusionConclusion

Remarks on thermodynamics of CHP systems

Cooling of SOFC systemsFP6-Project BiocellusConclusion

Contents

EconomicsEconomics



Biocellus Biocellus


Status quo SOFC development:

Main drawbacks are presently...

... degradation

... system efficiency

... high costs!

SOFC system for domestic heating

(Sulzer-Hexis)

RWE fuel cell pavilionMeteorit-Gelände, Essen

110 kW SOFC system, Siemens-Westinghouse

many highly promissing technical solutions are already available

EconomicsEconomics

European Energy Exchange (EEX) mean values 2002

German power revenues for biomass

0

2

4

6

8

10

12

SOFC ηel = 45%

"Off-Peak" (0-8h)

"High-noon" (11-14h)

SOFC/gas turbine ηel = 55%

-6

-4

-2

SOFC ηel = 45%with CHP

SOFC- ηel = 45%

with biomass/CHPco

sts

in c

t / k

Wh

cost

s in

ct /

kW

h elel

reve

nues

reve

nues

Invest costs

fuel costs

heat revenuesad

ded

valu

e

Problem: Efficiency of SOFC-systems with integrated gasification...

Biomass feedstock reduces fuel costs and increases power revenues

EconomicsEconomics



Biocellus Biocellus


waste heat can be sold for heating applications

fuel utilization ηB = 93 %

100 % 45 %fuel gas

900 °C

exhaustair supply

powerCHP principle:

fuel cell produces waste heat...

48 % heat utilization

7 % 120 °C

waste heattheory!

Combined Heat and Power (CHP) with SOFCs


EconomicsEconomics



Biocellus Biocellus



waste heat37

% 120 °C

reality!

CHP systems require alternative cooling concepts

18 %

heat utilization

technical solution:

Combined Heat and Power (CHP) with SOFCs

SOFC requires preheated air

SOFC operates with an excess air ratio of λ = 5-10 ... air preheater

100 % 45 %

900 °C

fuel gas

air supply exhaust

power

720 °C

180 °C


EconomicsEconomics



Biocellus Biocellus


active cooling of the stack (i.e. with Heatpipes) reduces excess air ratio

λ = 1


fuel utilizationηB = 89 %

44 %

100 % 45 %

900 °C

11 % 180 °C

760°C

fuel

air exhaust

power100 % 45 %

37 %

900 °C

fuel

air exhaust

power

18 %

180 °C

120 °C

760°C

Solution for CHP systems:

λ = 5


EconomicsEconomics



Biocellus Biocellus


anode

elektrolyt

cathode

airfuel gas

tubular design

current flow

interconnect

heat pipes

Example:

Tubular SOFC with Heat pipe cooling


evaporationcondensation

heat sink

heat source

condensateflow

vapor flow

Heatpipe characteristics:

Heatpipe technology allready successfully tested for indirect gasification of biomass...

liquid metal heat pipes at 800°C

Heatpipes provide favourable heat transfer charactersitics due to evaporation and condensationHeatpipes are absolutely isothermal

Brennkammer

Reformer

Heatpipes

High heating values (allothermal gasification) improve options for gas utilization integrated design favors small-scale (200 kW - 5 MW) distributed generation and Combined Heat and Power Generation (CHP)

European Project ENK-2001-00311

BioHPR- Biomass Heatpipe Reformer

Focus:standardized CHP units (600 kWFWL, 100 kWel ) with hot gas cleaning and microturbines in order to solve the tar problem

Vorlauf Heiznetz

Rücklauf Heiznetz

Strom

Biomasse

Bedien-station

Microturbine,Brennstoffzelle

EU-Project n° NNE5-2000-181Biomass Heatpipe Reformer

EconomicsEconomics



Biocellus Biocellus


x el. efficiency of the FC ηFC = 38%

system efficiency ηSystem = 30%

the gasifiers "cold gas efficiency" reduces system efficiency additionally

cold gas efficiency ηKG = 79%

79 % CO, CH4 H2

waste heat49 %

100 %

100 % Biomass

autothermal(air-blown)

gasifier

21 % sensible

heat

79 % CO, CH4 H2

el. output30 %

+ -ηel,BZ=38 %

el. efficiency ηel = 30 %

Fuel cell systems with integrated gasification

gas composition reduces fuel cell efficiencyBiocellusBiocellus

EconomicsEconomics



Biocellus Biocellus

ConclusionConclusionthe gasifiers "cold gas efficiency" reduces system efficiency additionally

Fuel cell systems with integrated gasification

gas composition reduces fuel cell efficiency

79 % CO, CH4 H2

waste heat49 %

100 %

100 % Biomass

autothermal(air-blown)

gasifier

21 % sensible

heat

79 % CO, CH4 H2

el. output30 %


+ -ηel,BZ=38 %

allothermal gasifier

(steam reformer)134 %

12 % sensible

heat

122 % CO, CH4, H2

100 %

100 % Biomass

waste heat 30 %

64 %

70 %

el. efficiency ηel = 26 % waste heat

44 %

+ -

ηel,BZ=42 %

x el. efficiency of the FC ηFC = 42%

system efficiency ηSystem = 26%

cold gas efficiency ηKG = 63%

feasible System efficiency with biomassapprox. 30%...

BiocellusBiocellus

EconomicsEconomics



Biocellus Biocellus


45 % 900 °C

79 %

900-1000 °C SOFC


heating of an indirectly heated gasifier (Heatpipe reformer) by means of the SOFCs exhaust increases system efficiency significantly

Heat pipereformer

"TopCycle"

Solution:

51 %+ -

ηel,BZ = 42 %

134 %

chemical bondedenergy 122 %

sensible heat 12%

800 °C

heat losses 4 %

100 %

34 %

100 %

34 %

combustion chamber

100 %

34 %

combustion chamber

BiocellusBiocellus

Part A: Biomass impact on SOFC membranes

WP 1: Assembly and Testing of a mobile SOFC test rig

WP 2: Investigation of the syngas impact on the fuel cell performance -

Membrane tests at different gasification sites

Result: Required gas quality

WP 3: Specification, layout and testing of the required gas cleaning system

WP 4: Design of a SOFC with internal heat pipe cooling

WP 5: Testing of the new SOFC concept

WP 6: Economic evaluation, environmental impact

WP 7: Dissemination activities

WP 8: Coordination

Verification and demonstration of appropriate gas cleaning technologies

Implementation of the TopCycle concept (Stack concept and thermal integration for biomass)

Part B:Technical

implementationEuropean STREP-Project

BioCellusproject start July 2004duration 3 years16 European partners

19

2

4

Task 2.3: air-blown circulating fluidized

bed gasifier

Task 2.2: air-blown downdraft fixed bed

gasifier

Task 2.6: two-stage gasifier (staged

air-blown gasification)

Task 2.4: Heatpipe Reformer (steam reformer

with hot gas cleaning)

Task 2.5: staged reforming (staged

steam reformer with cold gas cleaning)

Coordination gas requiriment test

CoordinationStack design

CoordinationGas Cleaning

technology

7

3

56

810

11

12

1314

15

16

Administrative Coordination

N°

1. Lehrstuhl für Thermische Kraftanlagen, TU München, Germany (Coordinator)2. National Technical University Athens, Greece3. MAB Anlagenbau, Austria4. TU Delft, The Netherlands5. ECN, The Netherlands6. HTM Reetz GmbH, Germany7. Prototech, Norway8. Institut für Kernenergetik und Energiesysteme, Universität Stuttgart, Germany9. Institut für Wärmetechnik, TU Graz, Austria10. Siemens, Erlangen, Germany11. Faculty of Chemistry and Chemical Powder Technology, University Lubljana, Slovenja12. DM2 GmbH, Essen, Germany13. COWI, Denmark14. Technical University of Denmark15. iT consult, Germany16. Aristotle University of Thessaloniki, Greece

Consortium:

EconomicsEconomics



Biocellus Biocellus


Economic situation of SOFC systems requires additional heat revenues and thus CHP systems

Using biomass instead of natural gas will improve the economic performance of SOFC/CHP systems additionally

Main challenges so far are... ... the impact of biogas / syngas on the fuel cells anodes ... appropriate gas cleaning technologies

and... ... stack designs with internal cooling (by means of heat pipes)

Conclusion


EconomicsEconomics



Biocellus Biocellus

ConclusionConclusionwe intend to submit a proposal for the long-term testing of the Heatpipe-Reformer

Possibilities for any co-operation are... ... material technologies (ceramics, steels)... Heat pipes

and... ... Microturbines (optimized to the needs of syngas)

Outlook...ConclusionConclusionConclusionConclusion

Vorlauf Heiznetz

Rücklauf Heiznetz

Strom

Biomasse

Bedien-station

Microturbine,Brennstoffzelle

please visit

http://www.biocellus.com

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Biocellus - Highly efficient SOFC systems with indirect ...€¦ · Biocellus - Highly efficient SOFC systems with indirect gasification International workshop on "Bio-energy workshop