Oxide Based Reforming Catalysts Alternative Processes: RF ... · 2 2.5 3 (mol%) Isotopic O18 from support is consumed initially before gas phase O16 participates in the reaction 1

Oxide Based Reforming Catalysts&

Alternative Processes: RF & Plasma

2009 SECA

Annual WorkshopAnnual Workshop

July 16, 2009

David A. BerryFuel Processing Group

Fuel Cell Systems

Research Situation – Fuel Processing

Fuel Fuel

ProcessorProcessorSyngas

SteamFCFC

StackStack

Fuel Cell SystemsFuel

Diesel

y g

Reforming TechnologiesPowerPower

Syngas (H2, CO, CH4...)

Plasma

Coal

Diesel

Applications• Stationary• MilitaryFuel Sources • Military• Transportation

Fuel Sources

F l R f iF l R f i

Key Enabling Technology

ConventionalConventional HH2 2

Fuel ReformingFuel Reforming

FuelsFuels SyngasSyngas

Conversion of fuels to H2 rich syngas necessary for the fuel cellCritical for successful commercialization

General ReviewGeneral ReviewGeneral ReviewGeneral Review

CleanExhaust

St•Hydrogen

FuelProcessor

Fuel CellPower

Section

PowerCondi-tionerFuel

Steam

DCPowerH2

Rich AC Power

•Natural Gas

• Propane

• GasolineGas

Gasoline

• Diesel

• Logistic Fuels

C l S

AirUsableHeat &

• Coal Syngas

CleanWater

R f I t tiReformer Integration

QReforming Options:

POx

Steam Reforming

Oxidative SR

Q Q

FuelReformer

Cathode

Air

Fuel

Oxidative SR

Steam Reformer

FuelCell

Stack

Anode

22mn H2mnnCOOnHHC ⎟⎠⎞

⎜⎝⎛ ++→+Steam Reforming - Endothermic

⎠⎝

( ) 2222mn N2n3.76H

2mnCO3.76NO

2nHC ⎟

⎠⎞

⎜⎝⎛++→++Pox Reforming - Exothermic

Technical Objective / Challenges

• Desired Thermal Integration with Fuel Cell – Similar Temperature of Operation:

Reduces unnecessary heat exchange and can increase system ffi i t & l it iefficiency – cost & complexity savings.

Challenges: Thermal processes too high temperature. Can be achieved by utilizing catalysts to lower reformation temperatures. Unfortunately, most hydrocarbon fuels contain sulfur and complex hydrocarbons that deactivate catalyst systems prematurely Commercial catalysts developed mostly forcatalyst systems prematurely. Commercial catalysts developed mostly for natural gas reformation & naptha.

• Possible Low or Waterless Operation:Reduces or eliminates the complexity and cost of managing water within the system. Some applications cannot consider water addition to the process.

Challenges: The use of water (usually excess) is the principle combatant toChallenges: The use of water (usually excess) is the principle combatant to carbon formation for commercial catalysts. Water however can also increase system efficiency by increasing hydrogen concentration via steam reforming & heat utilization: Cost vs efficiency trade-off.

Primary Goal

Identify, evaluate and/or develop viable hydrocarbon fuel processingtechnologies for high temperature solid oxide fuel cells being supported inthe NETL SECA program through fundamental understanding, research,and technology demonstration.

Fuel Technology End Use

Two Project Areas

Oxide-Based Catalyst Systems: Advanced Reforming Concepts:Oxide Based Catalyst Systems:

Apply fundamental understanding of fuel reforming & deactivation mechanisms into intelligent design

Advanced Reforming Concepts:

Identify and evaluate alternative non-catalytic and/or catalyst assisted processes to overcome

of alternative catalyst systems for long-term, stable hydrogen-rich synthesis gas production.

deactivation of traditional catalytic fuel reforming of higher hydrocarbon fuel compounds.

Oxide-Based Catalyst SystemsOxide-Based Catalyst Systems

Project Objectives - Approach

• Gain a fundamental understanding of catalyst function and mechanism offunction and mechanism of deactivation.

• Apply understanding and lessons learned to design improved performance catalyst systems & demonstrate long-term performance.term performance.

Deactivation Issues – Why?

12

14

Reforming catalyst aging

uel)

2

4

6

8

10

yie

ld (m

ol/m

ol-f

AirHC Fuel

Recyc.ExhaustVaporizing S poisoning

00 20 40 60 80 100

Time on stream (hr-1)H

2

ExhaustS S S S

VaporizingAgglomeration

S poisoning

C-deposit

Reformate (H2, CO, CH4...)

Catalyst Deactivation

Support Collapse

( 2, , )

Catalyst ProgressionCatalyst Progression

Traditional Inert Supported Ni

Nobel Metal AdditionsNobel Metal Additions

Conductive Supports

Oxide-Based Catalysts

Oxide-Based Catalysts w/conductive supports

Ni quickly deactivates in presence of higher hydrocarbons…especially under Pox or low water conditions




Conductive Supports



Noble metals such as Rh demonstrated superior carbon and sulfur formation/tolerance

Carbon Formation Mechanism

2H2

CH4 CO

SurfaceMigration

C

MetalC t l t

C

(3) (4)O

18 O O

C

Catalyst

Catalyst Support

Oxygen exchange at metal/support interface would seem important for C oxidation




Conductive Supports



What’s the role of the support?

Pt/Alumina. POM. 700C, P=14psig

Effect of support-type on H2 generation

Pt catalysts on non-conducting supports showed

2

4

6

8

ydro

gen

(mol

%)

O/C=1

O/C=0.8

O/C=0.66

O/C=0.62

O/C=0 57

conducting supports showed both poor performance and rapid deactivation.

00 10 20 30 40 50

Minutes

Hy O/C=0.57

O/C=0.44

Pt/C O2 POM 700C P 14 i Pt catalysts on oxygen ion

6

8

1012

14

gen,

mol

%

O/C=1O/C=0.9O/C=0.8O/C=0.66O/C=0.57

Pt/CeO2, POM , 700C, P=14psig Pt catalysts on oxygen ion conducting supports (CeO) exhibited stable performance even in very low oxygen

0

24

6

0 10 20 30 40 50

Minutes

Hydr

og O/C=0.44O/C=0.4

environments.

Support type matters

Effect of Ionic Conductivity of SupportEffect of Ionic Conductivity of Support on Carbon Formation

Partial Oxidation of Methane, 700C

0 15f

0.10

0.15

amou

nt o

rbon

(g)

Pt/ZDC

Pt/CeO2

0.00

0.05

0 30 40 50 60 70 80 911 1

Tota

l ca

r

Pt/GDC10

Pt/LaDC15

0.30.40.50.60.70.80.911.1O/C

Pt/GDC30

The higher the ionic conductivity of the support, the less carbon formation is observed.

I i O 18 T S di L b l d SIsotopic Oxygen18 Tracer Studies – Labeled Supports

P ti l O id ti f M th L b l d Rh/ZDCPartial Oxidation of Methane over Labeled Rh/ZDC

2

2.5

3

(mol

%) Isotopic O18 from support is consumed initially

before gas phase O16 participates in the reaction

1

1.5

2

dist

ribut

ion

(

CO 12 16CO 12 18

0

0.5

14:34 14:48 15:02 15:17 15:31 15:46Time (min)

CO

Time (min)

Isotopic studies corroborate carbon oxidation is initiated by O2in the support.

18

C t ti fil f 18O i & t POM

18O concentration/Catalyst depth

Concentration profiles of 18O prior & post POM over 18O2 labeled catalysts at 700C

4.5*10E18Total no. of atoms

4

5

tom

s%

5*10E17 3*10E18 2*10E19

1*10E21

of atoms

Surface catalyst

2

3

once

nt. A

t 1*10E21catalyst

0

1

0 397 3175 6191 22064

18O

co

0 397 3175 6191 22064Catalyst Depth (nm)Prior POM

Post POM




Conductive Supports



Are oxide-based catalysts beneficial?

Additional Performance Characteristics

Other important observations:• Small “nano-sized” catalyst sites exhibit better activity and lower overall carbon formation.

•Well-dispersed active reaction sites exhibit betterWell dispersed active reaction sites exhibit better tolerance to sulfur and carbon deactivation.

How do we take advantage of these characteristics?

Oxide based Catalyst SystemsOxide-based Catalyst SystemsGeneral Formula

ABO

A-site cationB-site cation

ABO

cation

Oxygen anion

Doping the lattice of certain oxide-based compounds with catalytic metals results incatalytic metals results in…•A structured catalytic surface with nano-sized metallic crystallites that serves as a template to control metallic crystallite size and dispersion.

Oxide Based Catalyst Performance

100

Oxide-Based Catalyst Performance

70

80

90

100

LSRZ

A conductive oxide-based catalyst was doped with 1% Rh along with a SOA Rh catalyst on alumina. After exposure to a severely carbon producing fuel

30

40

50

60

Yiel

d (%

)

Rh/γ-Al2O3

5 wt% 1-MN & 1000 ppmw S added

5 wt% 1-MN & 1000 ppmw S removed

severely carbon producing fuel compound, the oxide-based catalyst performance remained stable, while the non-conducting supported catalyst deactivated significantly.

Experimental conditions T=900°C, P= 20 psig, GHSV= 50,0000

10

20

0 50 100 150 200 250 300 350

Time on stream (min)

Oxide based catalysts appear to exhibit better stability/performance than their bulk metal catalyst counterpart.




Conductive Supports


Oxide-Based Catalysts w/conductive supportsOxide Based Catalysts w/conductive supports

Is there a benefit?

Oxide Catalyst on O2 Conducting Supports

Metal OxideC t l tCatalyst

Oxygen Conducting Catalyst Support

Metal oxide-based catalyst on oxygen-conducting supports may perform better

1000 hour Endurance Test

Long-Term Testing

Fully reformed local pump dieselEquilibrium syngas yields achievedSurvived multiple system upsetsO/C=1, H2O/C=0.5

25

30

700

800

900

H 2

Water f il d

Water

15

20

mpo

sitio

n (%

)

500

600

Olefins Produced

Hydrogen

CarbonMonoxide

CO

pump failed pump on

5

10

Com

200

300

400

d (ppm)

MonoxideCarbonDioxideMethane

Olefins

CO 2

4

0

5

0 200 400 600 800 1000 1200

Time on Test (hrs)

0

100Olefins= ethylene + propylene + C-ene + benzene

Monolithic Reforming Catalyst

Base Support: 400 cpi alumina-based

Coated Monolith: Incorporates NETL pyrochlore catalyst systembased catalyst system

T h T f A ti itiTech Transfer Activities20102009

Catalyst DevelopmentCatalyst DevelopmentStrategy: Develop long-term test data for FC fuel reforming to share with developers & catalyst companies to

t h t f li i d

Long-term Powder Data

(NETL)

CRADA Commercial

Partner (TBD)

Monolithic Catalyst Test

(NETL) encourage tech transfer, licensing and collaboration.-Contract with Nextech for coated monoliths-Collaboration w/PCI for microlith catalyst evaluation

Patent Application

( )

Monolithic Catalyst Fab

( )( )

PCI Microlith Evaluationevaluation

-- Discussions w/Sud Cheme

Reactor DemonstrationReactor Demonstration

(Nextech)

PCI R tBi di l FC D l hi / OthStrategy – Conduct demo through integrated biodiesel fuel cell test @ NETL. -Possible evaluation w/Delphi and/or other interested developers-Planned demonstration with PCI

PCI Reactor Evaluation

Biodiesel FC Demo (NETL)

Delphi / Other Evaluation?

FY 2009 Publications

P R i d P bli tiPeer Reviewed Publications

D. Shekhawat, D. A. Berry, D. J. Haynes, J. J. Spivey, Fuel Constituent Effects on Fuel Reforming Properties for Fuel Cell Applications, Fuel,g p pp , ,88 (2009) 817-825.

D. J. Haynes, A. Campos, D. A. Berry, D. Shekhawat, A. Roy, J. J. Spivey, Catalytic Partial Oxidation of a Diesel Surrogate Fuel Using an RuCatalytic Partial Oxidation of a Diesel Surrogate Fuel Using an Ru-Substituted Pyrochlore Catalysis Today (accepted).

D. Shekhawat, D. A. Berry, J. J. Spivey, ‘Preface’ for the special issue of Catalysis Today about Hydrogen Production for Fuel Cell Applications (Guest Editors), Catalysis Today, 136 (2008) 189.

D J Haynes D A Berry D Shekhawat J J Spivey Catalytic PartialD. J. Haynes, D. A. Berry, D. Shekhawat, J.J. Spivey, Catalytic Partial Oxidation of n-Tetradecane Using Pyrochlores: Effect of Rh and Sr Substitution, Catalysis Today, 136 (2008) 206-213.

FY 2009 Publications cont…

C f P t ti /P diConference Presentations w/Proceedings

D. J. Haynes, D. A. Berry, D. Shekhawat, M.W. Smith, J.J. Spivey, Catalytic Partial Oxidation of Diesel Surrogate Fuel Using Optimized y g g pNi-Catalysts International Symposium on CATALYST DEACTIVATION, The Netherlands, Delft, October 25 - 28, 2009.

M W Smith D J Haynes D A Berry D Shekhawat J J Spivey EffectM.W. Smith, D. J. Haynes, D. A. Berry, D. Shekhawat, J.J. Spivey, Effect of oxide catalysts and oxygen-conducting supports on partial oxidation of liquid hydrocarbons, The 237th ACS National Spring Meeting, Salt Lake City, UT, March 22-26, 2009.

J. J. Spivey, D. J. Haynes, D. A. Berry, D. Shekhawat, Fuel Processing of n-Tetradecane: Catalytic Partial Oxidation on Rh- and Ru-Substituted Metal Oxides 7th International Workshop on Catalytic CombustionMetal Oxides, 7th International Workshop on Catalytic Combustion, Lake Zurich, Switzerland, Sep 29-Oct 1, 2008.


C f P t tiConference Presentations

D. J. Haynes, D. A. Berry, D. Shekhawat, M.W. Smith, J.J. Spivey, Catalytic Partial Oxidation of a Surrogate Diesel Fuel Mixture Using y g gPyrochlores: Effect of Reforming Metal, 2009 AIChE Spring National Meeting, Tampa, FL, April 26-30, 2009.

M W Smith D J Haynes D A Berry D Shekhawat J J Spivey EffectM. W. Smith, D. J. Haynes, D. A. Berry, D. Shekhawat, J.J. Spivey, Effect of catalyst layer formation and character on partial oxidation of liquid hydrocarbons in the presence of oxygen-conducting supports, 2009 AIChE Spring National Meeting, Tampa, FL, April 26-30, 2009.

J. J. Spivey, D. J. Haynes, D. A. Berry, D. Shekhawat, M.W. Smith, Hydrogen Production from the Catalytic Reforming of Hydrocarbons, 2009 Gordon Research Conference on Hydrocarbon Resources2009 Gordon Research Conference on Hydrocarbon Resources, Ventura, CA, January 11-16, 2009.


Posters

D. J. Haynes, D. A. Berry, D. Shekhawat, M.W. Smith, J.J. Spivey, Catalytic Partial Oxidation of n-Tetradecane over Rh Substituted Pyrochlores: Effect of A-site Substitution, 21st North American Catalysis Society Meeting, June 7-12, 2009, San Francisco, CA.

M.W. Smith, D. J. Haynes, D. A. Berry, D. Shekhawat, J.J. Spivey, Reforming Liquid Hydrocarbons with Ni-substituted Barium Hexaaluminates: Effect of Oxygen-conducting Support, 21st North A i C t l i S i t M ti J 7 12 2009 SAmerican Catalysis Society Meeting, June 7-12, 2009, San Francisco, CA.


Patents

S S SD. A. Berry, D. Shekhawat, D. J. Haynes, M.W. Smith, J. J. Spivey, Pyrochlore Materials for Chemical Reaction Systems, Patent Disclosure, April 14, 2009.

Acknowledgements

R h TResearch Team:

Dave BerryDushant ShekhawatDaniel HaynesMark SmithDon FloydMike BergenMike BergenJerry Spivey (LSU)

Oxide Based Reforming Catalysts Alternative Processes: RF ... · 2 2.5 3 (mol%) Isotopic O18 from support is consumed initially before gas phase O16 participates in the reaction 1

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