wp 2: gas processing unit 1 strictly confidential workpackage 2: gas processing unit kti review...

WP 2: Gas Processing Unit1

http://www.nonmet.mat.ethz.ch/research/onebat

Strictly Confidential

Workpackage 2: Gas Processing Unit

KTI Review Meeting, May 11, 2005

M. Stutz, N. Hotz, Dr. N. Bieri, and Prof. D. Poulikakos

NTBINTERSTAATLICHE HOCHSCHULEFÜR TECHNIK BUCHS




Contributions to WP 2

NTB

NMW

Butane Reforming

Post Combustion Integration and Testing

Inlet conditions Compatibility with FC

Heat exchange

Feed / Exhaust

Micromachining

Coating

NTBNMW

Coating

Coating

Micromachining

Coating




Project Management

Thermal System

Fuel Cell

Gas Processing

WP 2: Year 1 Milestones

• performance 200 mW/cm2 @ 550°C• external electrical connections

• butane conversion rate > 90%• post-combustor with gas oxidation

> 98%

• battery expert• industrial partner

• thermal insulation concept with Tinside 550°C, Toutside 50°C, <10 cm3

• structures for validation critical points• thermal system demonstrator with simulated 2 W heat source




Main Achievement after 12 Months

• Optimized butane reforming performance at 600˚C!

Hydrogen Yield:

Results @ month 12

Results @ Month 6




Overview

• Our Main Task in this Project

• WP 2.1: Reformer

• WP 2.2: Post-Combustor

• WP 2.3: Integration and Testing

• Validation of Milestones

• Next Steps




Our Main Task in this Project

• FC System:

• Reformer:

• Post Combustor (PC):




Overview






• Next Steps




WP 2.1: Reformer

Main Tasks:

• Understanding the butane reforming at low temperature (600˚C)?

– Experiments with packed bed reformer

• influence of plugs is significant

• activation/deactivation of catalyst

• Reforming with the disk reactor:

– Coating of the disk reactor

– Influence of sealing

– Activation/deactivation of catalyst

• New challenge

– Modified product specification (from 1 W to 2.5 W power output)

→Build-up of modified test rig




Month 12: Milestones (MS)

• MS @ month 12: reformer demonstrator with significant butane

conversion rate @ 600°C and stable for feeds of 0.02 to 0.5 g/h

butane incl. gas chromatography (fabrication: NTB, testing: LTNT)

– Optimized experiments: packed bed reformer

– Modified design in progress (disk reactor)




Experimental Results

• Comparison: Packed bed reactor

– Empty tube

– Reformer with plugs 'O' (Al2O3/SiO2, old)

– Reformer with plugs 'N' (SiO2, new)

– Thermodynamic equilibrium




Reactor Performance

• Butane conversion

4 10 4 10

4 10

C H ,in C H ,out

C H ,in

n n

n

• for T > 450 °C:

→ high η for 'plugs N'

• for T < 450 °C:

→ high η for 'plugs O'

• η of empty tube is low

→ effect of catalyst

• at T = 600 °C:

→ η = 69.2 % for 'plugs O'

→ η = 93.0 % for 'plugs N'

POXTOX

Total Oxidation (TOX): C4H10 + 6.5 O2→5 H2O + 4 CO2

Partial Oxidation (POX): C4H10 + 2 O2→5 H2 + 4 CO




Reactor Performance

• Hydrogen Yield

2

4 10,in

H

C H5

n

n

• for T > 450 °C:

→ high ψ for 'plugs N'

• for T < 450 °C:

→ high ψ for 'plugs O'

• ψ is higher than equilibrium

• at T = 600 °C:

→ ψ = 45.5 % for 'plugs O'

→ ψ = 86.6 % for 'plugs N'

POX

TOX

TOX: C4H10 + 6.5 O2→5 H2O + 4 CO2

POX: C4H10 + 2 O2→5 H2 + 4 CO




Outlet composition

• Reformer with plugs 'N' (SiO2, new)

• Outlet composition:• at T = 600 °C:

– XH2O = 4.6%

– XH2 = 23.0%

– XCO = 13.2%

→ Enhanced FC performance if

XH2O ≈ 5%POX

TOX

→ Inlet conditions of FC to NMW / EPFL




Disk reactor

• Experimental results of Disk reactor

– Coating: Rh (sputtered by NTB)

– T = 600°C, ddisk = 8 mm, GSV = 25 s-1

PBR

DR

PBR

DR

Reason:

• Sealing?

• Coating?

Butane Conversion:

Hydrogen Yield:Alternative:

• Filling disk space with catalyst

particles (packed bed)




Overview






• Next Steps




WP 2.2: Post Combustor (PC)

Purpose of PC: Catalytic oxidation of (toxic, flammable) exhaust gases

– e.g. C4H10 + 6.5 O2 → 4 CO2 + 5 H2O

– e.g. CO + 0.5 O2 → CO2

• Several studies in literature

– Choice of catalyst and support: (Pt Ce0.5Zr0.5O2)

• PC design similar to reformer (constraints: stack integration)

• Composition of gas at inlet?

• Modified product specification




Milestones (MS)

• MS @ month 12: first preliminary post-combustor demonstrator

aiming for significant oxidation rate @ 600°C and stable for feeds of

0.02 to 0.5 g/h butane (fabrication: NTB, testing: LTNT)

– Modified product specification

(from 1 W to 2.5 W power output → Modified test rig)

– Inlet gas composition not known

(CO, CH4, C4H10 conversion in Fuel Cell?)

– Reforming with disk reactor not yet satisfied

– Catalyst particles are active (and already produced by LTNT)W. J. Stark, J. D. Grunwaldt, M. Maciejewski, S. E. Pratsinis, A. Baiker, "Flame-made Pt/ceria/zirconia for low-

temperature oxygen exchange", Chem. Mater., 17 (13) 3352-3358 (2005).

ongoing




Overview






• Next Steps




WP 2.3: Integration and Testing

• MS @ month 12: delivery of first reformer and post-combustor

designs aiming for compatibility with heat exchanger and hot

module processing (LTNT)

– Final design: disk reactor

– Initial specifications: dimensions determined

– Altered Specifications: Dimensions to be determined

ongoing




Overview






• Next Steps




Validation of Milestones and Deliverables


Month 12: delivery of first reformer and post-combustor designs aiming for compatibility with heat exchanger

and

hot module processing (LTNT)

• WP 2.2: Post-combustor

Month 12: first preliminary post-combustor demonstrator aiming for significant oxidation rate @ 600°C and

stable

for feeds of 0.02 to 0.5 g/h butane (fabrication: NTB, testing: LTNT)


Month 12: reformer demonstrator with significant butane conversion rate @ 600°C and stable for feeds of 0.02

to 0.5 g/h butane incl. gas chromatography (fabrication: NTB, testing: LTNT)

ongoing

• Previous Milestones and Deliverables: all fullfilled




Summary of Results

• Optimized butane reforming at low temperatures (PBR)

• Ongoing butane reforming experiments with DR

• Active catalyst particles for Post-Combustor

• DR design for integration into hot module




Overview






• Next Steps




Next steps (Year 2)

• WP 2.1: High performance of disk reactor at T = 600°C:

Butane conversion > 80%, hydrogen selectivity > 60%

– (Coating in collaboration with NTB and NMW)

• WP 2.1: Long-term stability tests of reformer at T = 600°C:

Butane conversion loss < 10% (after 10 h steady state)

• WP 2.2: Improved performance of post combustor:

exhaust gas oxidation > 98% at T = 600°C and 0.7 g/h butane

feed

– (Inlet conditions for PC from NMW and EPFL)

• WP 2.3: Integration of reformer and PC into hot module

– (Constructal constraints from NTB and ZHW)

NMWNTB

NMW

NTB




Next steps (Year 3 / Year 4)

• WP 2.1: Optimized performance of disk reactor at T = 550°C:

Butane conversion > 90%, hydrogen selectivity > 75%

– (Inlet gas composition to NMW / EPFL)

• WP 2.1: Start-up stability tests of reformer:

Butane conversion loss < 10% (after 5 cycles from 25°C to

600°C)

• WP 2.2: Optimized performance of PC at T = 550°C:

CO conc. < 25 ppm (TLV, ACGIH).

– (Operation parameters from NMW / EPFL, ZHW / NTB)

• WP 2.2: Start-up stability tests of PC:

CO conc. < 25 ppm (after 5 cycles from 25°C to 600°C)

NMW

NMW

NTB




Questions ?

• Optimized butane reforming performance at 600˚C!

Hydrogen Yield:

Results @ month 12

Results @ Month 6




Validation of Milestones and Deliverables


Month 3: first reformer design available (LTNT)

Month 6: modelled and evaluated reformer based on 0.3 g/h butane in 2 cm3 with T max difference 50°C

(reformer modelled for methane): effect of thermal conductivity of the reformer walls on the

reformer process, microchannels coated with catalyst vs. porous catalyst (LTNT)

• WP 2.2: Post-combustor

Month 3: first preliminary post-combustor design available

Month 6: improved designs of post-combustors aiming for 0.3 g/h butane feed, fully oxidized in 1 cm3 @

600°C and max. pressure drop of 3 Pa (LTNT)


Month 3: design of test rig available (LTNT)

Month 6: test rig for reformer and post-combustor for GPU performance incl. gas chromatograph (LTNT)

Deliverables:

Month 3: reformer design from LTNT NTB for evaluation

Month 6: final reformer design from LTNT NTB for fabrication

Deliverables:

Month 6: designs of post-combustor from LTNT NTB for fabrication

Deliverables:

Month 3: design from LTNT NTB

Month 6: NTB samples LTNT (P. Müller checks whether possible in month 6)

wp 2: gas processing unit 1 strictly confidential workpackage 2: gas processing unit kti review...

Documents

confidential wp

plugs o

reformer wp

project wp

gas oxidation

postcombustor wp

plugs n pox tox tox

confidential contributions