Manufacture of Solid Oxide Fuel

Cells byCo-extrusion

Jonathan Powell1,2 and Stuart Blackburn2,3

1. Department of Metallurgy and Material Science2. Interdisciplinary Research Centre in Materials Processing3. Department of Chemical Engineering

Project summary

Rheology Packing density Co-extruder design Pressure modelling Co-extrusion

Motivation

Sustainable energy production. Wide range of fuels Rapid start up Thermally and mechanically stable High power densities High production costs

Objectives and scopeMicro tubularsolid oxide fuel cell

Co-extrusion

Liang & Blackburn, J. Mat. Sci., 37, 2002

Stage 1 Stage 2

Stage 3 Stage 4

Building of repeating units

Multi-billet extrusionBuilding of laminated tube

Paste rheology unification The pastes must flow in a uniform

manner The pastes must therefore have

unified rheological properties

Prediction of powder packing densities

Packing predictions from extended Westman model

Paste rheological characterisation

nm VD

L

D

DVPPP

0

0021 4ln)(2

o Bulk yield stress

Velocity factor convergent flow

n Velocity exponent convergent flow

Die wall shear stress

Die wall velocity factor

m Die wall velocity exponent

Rheological unification

Co-extruder design

Co-extruder design features

nm VAMLVAAPPP 00021 ln

Co-extruder design features

cot1lncot22

0

10010

nnm

D

D

n

V

D

DVP

nn

Dc

DccDcD

nc

V

cDDP

cot

cottantan

1cos

00

00

Pressure predictions

Co-extrudate

Sintered microtube

Conclusions

Shaping of multilayered ceramic microtubes.

Formulation paste predictions. Predict co-extrusion pressures. Adapted for continuous co-processing

of complete SOFCs

Acknowledgements

Thanks goes to; Prof Stuart Blackburn for his support

and supervision EPSRC for the funding of this research Sandvik for funding my participation in

this conference

S Blackburn 2004