Separation enhanced reactors for

de-carbonisation of fossil fuels

Peter Alderliesten & Daniel JansenEnergy research Centre of The Netherlands

Palo Alto , 26 April 2004

Content

• Introduction - ECN- Relevant R&D programmes - De-carbonisation of fossil fuels

• Separation enhanced reactors- Why- Membrane reactors - Sorbent reactors

• Conclusions

ECN

MissionWe develop high level knowledgeand technologies for a sustainable energy system

Priority areas:Energy efficiency & conservation• Solar PV• Wind• Biomass• Clean Fossil fuels & Fuel cell technology

ECN (2)

ECN’s core competence and added value• Materials R&D • (electro)catalyst R&D• Process technology• System analyses

• Large and complex programmes and projects• Extended experimental facilities• Networks with universities and stakeholders

Relevant ECN R&D programmes• Energy Efficiency in Industry

- Separation Technology• Inorganic membranes • Membrane reactors• Membrane processes

• Clean fossil fuels- H2 as energy carrier/fuel

• Production with CO2 capture• End-use for power production in gas turbines and fuel cells

De-carbonisation of fossil fuels

• Natural gas to hydrogen- Steam reforming- Water gas shift- Hydrogen/CO2 separation

• Coal to hydrogen- Gasification- Water gas shift- Hydrogen/CO2 separation

Separation enhanced reactors

Steam reforming: CH4 + H2O 3 H2 + CO (∆H = 206 kJ/mol)

Water-gas shift: CO + H2O H2 + CO2 (∆H = - 41 kJ/mol)

CH4 + 2 H2O 4 H2 + CO2

Steam reforming: CH4 + H2O 3 H2 + CO (∆H = 206 kJ/mol)

Water-gas shift: CO + H2O H2 + CO2 (∆H = - 41 kJ/mol)

CH4 + 2 H2O 4 H2 + CO2CH4 + 2 H2O 4 H2 + CO2

CH4 + H2O

H2 H2

CO2 + H2O

Pd-membranecatalyst

CH4 + H2OCH4 + H2O

H2 H2

CO2 + H2O

H2 H2

CO2 + H2O

Pd-membranecatalystcatalyst

14% CH4,86% H2O

SMR-cat.+

Adsorbent

14% CH4,86% H2O

SMR-cat.+

Adsorbent

•Membrane reactors •Sorption enhanced reactors

SERWhy

• Advantages- integration of process steps thus

• lower temperatures• high product yield

- cheaper construction materials- compactness - energy savings

• Disadvantages- not yet proven technology- complex unit operation- less degree of freedom in design

Membrane reactor R&D at ECN

Process concept

Selectivity

Preliminary membrane reactor requirements

Flux

Robustness

Reproducibility

ResultsProcess concept hydrogen production for ammonia

Desulphurisation

Reformer1

Reformer2 HT Shift LT Shift

CO2 removalMethanation

Natural gas

Steam Air

Syngas(H2 + N2) CO2

Fuel gas

800 oC 980 oC480 oC 350 oC 200 oC

50 oC275 oC

H2OH2O

140 bar 30 bar

43 bar

Desulphurisation

Reformer1

Reformer2 HT Shift LT Shift

CO2 removalMethanation

Natural gas

Steam Air

Syngas(H2 + N2) CO2

Fuel gas

800 oC 980 oC480 oC 350 oC 200 oC

50 oC275 oC

H2OH2O

140 bar 30 bar

43 bar

Desulphurisation Membrane Reactor

Natural gas Steam

N2

Syngas(H2 + N2)

CO2 + H2OH2 H2 H2

Desulphurisation Membrane Reactor

Natural gas Steam

N2

Syngas(H2 + N2)

CO2 + H2OH2 H2 H2H2H2 H2H2 H2H2

Conventional

New scheme including membrane reactor

Energy saving: 12%

ResultsProcess concept hydrogen for power generation

Air

FuelCO2+H2O

ReformerShift

membraanburner

H2+H2OH2 combustion

STEAM REFORMINGSHIFT-REACTiION

MembraneH2

H20

H20

Air

Recuperation waste heat

useg

Fuel

CO2 storageRefomer

ShiftMembrane

BurnerH2O

~Air

Recuperation waste heat

useg

Fuel

CO2 storageRefomer

ShiftMembrane

BurnerH2O

~

CO2 capture cost can be reduced with 50%

ResultsPreliminary requirements

- High selective, high flux, membrane operating at 300- 500 C

- Hydrogen recovery >98%- Process membrane flux 50 ~100 kW(H2-eq.)- Membrane price ~ 1400 Euro/m2

- Membrane lifetime > 2 years

Approach- Development of asymmetric, thin layer Pd/alloy

membranes- Membrane/process testing- Basic unit design

ResultsThin layer Pd alloy membranes

Production procedure:• Pd precursor variation

• Controlled nucleation

• Sequential electroless plating (growth)

• Annealing/alloying

Thin layer defect free membrane ~ 3 micron

ResultsThin layer Pd alloy membranes (2)

80 cm

Metal substrate Ceramic substrate

1m2 scaleend-cap

connector

ResultsPerformance measurements ECN Pd/Ag membranes

Pf= feed pressure in bara

Pp= permeate pressure in bara

0

20

40

60

80

100

120

200 250 300 350 400 450

Temperature (o C)

H 2 p

erm

eanc

e (m

3 /m2 hb

ar0.

5 )

Pf/Pp=24/3Pf/Pp=23/3Pf/Pp=11/3Pf/Pp=7/3

SMR-conditions• Stable operation

for 3 months

• SelectivityH2/CO2 ~ 4000

• Permeance 50 ~ 100 kW H2-eq

• T-Cycling in N2 o.k!

9

ResultsAgeing !

Before use Ageing in hydrogen

ResultsEquipment development: Module design and sealing

• 600°C, 150 bar

• Reducing atmosphere

200 Nm3/hr12 m2

Conclusions and future work MR

• Conclusions- Pd/alloy membrane promising technology- Process concepts look feasible- Membranes are dynamic

• R&D issues near future- Performance: understanding flux/selectivity in operation- Stability: fouling, poisoning, material microstructure- Reproducibility: upscaling aspects- Detailed module design, construction, MR experiments

Sorption enhanced reforming processbasic aspects

SER reactor 1:adsorption mode

PSA ?

CH4 + H2O

H2

SER reactor 2:desorption mode

CO2 + H2O High Temp. steam

• Cyclic batch operation• Steam-reforming/water-gas shift reaction• Pressure swing adsorption optional• Hydrotalcites as promising CO2-adsorbents

H2

Heat

Results SERPBase case system analysis

High efficiency

• Three main challenges:- High conversion of CH4 (>98%) needed- Reduction of CO2 stripping steam < 3 moles steam / mole CO2

- 85% CO2 capture

• Approach- Improve/new catalyst and adsorbent- Process optimization (cycle times) - Innovative system configurations

Results SERPCH4 conversion

4

5

6

7

8

9

0 20 40 60 80 100Cycle number

CO

2up

take

/rele

ase[

ml]

0%

20%

40%

60%

80%

100%

conv

ersi

on [%

]

adsorbed CO2

CH4 conversion

desorbed CO2

Equilibrium CH4 conversion @ 400°C

4

5

6

7

8

9

0 20 40 60 80 100Cycle number

CO

2up

take

/rele

ase[

ml]

0%

20%

40%

60%

80%

100%

conv

ersi

on [%

]

adsorbed CO2

CH4 conversion

desorbed CO2

Equilibrium CH4 conversion @ 400°CEquilibrium CH4 conversion @ 400°C

ECN catalyst/sorbent

•98% conversion at 400 oC until breakthrough of CO2

•85% CO2 capture

• Steam/CO2 ratio > 10

•Ad=des

Results SERPLowering steam demand

• Modification of adsorbens:- Promising new hydrotalcites and

promoters found• Alkali metal carbonates

- Further development on going in co-operation with Utrecht University

• Process optimization:- Short cycle times- Dynamic modeling of

adsorption/desorption process

Results SERP System Configurations

• System and pinch analysis, • Identification of innovative process

schemes with gas turbines and fuel cells

SERCH4 conversie = 66 %CH4 H2

CO2

PSAScheiding = 85 %

CH4Steam

H2

SER + REF + PSA

REFORMERCH4 conversie = 44 %

CH4H2

CH4

17 mol14680 kJ

(feed)

67 mol2669 kJ(feed)

+119 mol4751 kJ(purge)

11 mol

2720 kJ(rookgas)

3 mol2097 kJ

CH4

46 mol12864 kJ

Overall conversie = 85 %

η = 80 %

H2

8 mol2001 kJ

H2

Hot flue gas

steam1762 kJ 400 kJ

1588 kJ40 mol

(non-used steam)

17 mol14680 kJ(Bijstook)

H2O

SERCH4 conversie = 66 %

SER (ATR) + Compressor + Turbine

CH4 CH4,H2N2,CO

CO2

LP AIR

TurbineCompressor

Combustion Chamber

HP AIR

20 mol17901 kJ

(feed)+

2 mol2148 kJ(reactie)

122 mol4882 kJ(feed)

+117 mol4661 kJ(purge)

54 mol15037 kJ

(H2)+

7 mol6086 kJ(CH4)

17 mol

Rendement = ?? %

η = 80 %

Hot flue gas

Elec-tricity

Steam

1588 kJ40 mol

(non-used steam)

H2O

Conclusions and future work SERP

• Conclusions- Methane conversion > 98% feasible at T=400 C- No breakthrough of CO2- CO2 removal efficiency of 85 % feasible- No hysterisis

• R&D issues- Steam/CO2 ratio < 3 (shallow ad- desorption mode)- ATR – SERP (GT application)- Preparation methode cat/sorbent combi- Sorbent lifetime

Final

• Separation enhanced reactors - MR and SERP in progress- Next two years decisive

• Acknowledgements- Colleagues and co-workers

• Ruud v.d. Brink, Paul Pex, Yvonne van Delft, Lucy Correia, Jan Wilco Dijkstra and others

- GSEP for the invitation- Sponsors

• Dutch ministry of Economic Affairs, EU, e.o.