Eltron Research & Development An Analysis of …...Eltron Research & Development An Analysis of Dense Hydrogen Membranes as a Means of Producing a CO 2 Rich Stream Consistent with

Eltron Research & Development

An Analysis of Dense Hydrogen Membranes as a Means of Producing a

CO2 Rich Stream Consistent with the CO2

Capture Requirements of a FutureGen Plant

Twenty-Third Annual InternationalPittsburgh Coal Conference

September 26, 2006

Paul J. Grimmer, Xiaobing Xie, Carl R. Evenson IV, Harold A. Wright – Eltron Research; Clive Brereton &

Warren Wolfs - NORAM


Slide 2

Coal, Hydrogen & FutureGen

� Coal is an abundant global energy resource. In the U.S. alone there are over 200 years’ reserves.

� Coal can be produced cheaply, much at less then $1/MMBTU ($70/bbl oil is $12.70/MMBTU).

� Coal has a multitude of contaminants.

� Coal contains very little H2. Energy from coal comes from C combusting to CO2. Compared to natural gas, coal causes over 3 times the CO2 emissions per MW (or mile driven etc.).

� The FutureGen initiative is to develop a 275 MW coal-fired power plant that also produces H2 and has zero (or near zero) emissions, including CO2.


Slide 3

Carbon Capture - Methods

� Post – Combustion

� Remove CO2 from combustion exhaust gases

� Pre-Combustion

� Convert fuel to CO2 and H2, remove CO2 before burning

� Oxy-Fuels

� Fire combustion with O2 instead of air

� Remove CO2 from exhaust gases


Slide 4

Post-Combustion CO2 Capture

� Remove CO2 from combustion gases

� Typically via amine absorption/regeneration

� Advantages

� Processes are established

� Can be applied to existing combustion systems

� Disadvantages

� Highest cost alternative

– Combustion exhaust (amine unit inlet) is typically < 15% CO2

– Combustion gas is typically at low pressure

� Recovered CO2 is at low pressure


Slide 5

Oxy-Fuels (with post-combustion CO2 Capture)

� Combustion with O2 instead of air

� Combustion exhaust is mainly CO2 and H2O

� Advantages

� Less exhaust gas to process (no N2)

� Separation is easier (mainly CO2/H2O separation)

� 30% cheaper than post-combustion method

� Disadvantages

� Generally requires new combustion system (higher combustion temperatures)

� Requires recycle of a portion of the exhaust gas for temperature control

� Requires O2 via cryogenic ASU (or perhaps membranes)

� Technology still in development


Slide 6

Pre-Combustion CO2 Capture

� Fuel conversion

� Feed is converted to synthesis gas

� Synthesis gas is “water-gas shifted” to a stream of CO2 and H2

� CO2 removed prior to H2 combustion.

� Advantages

� Can be 60% cheaper than post-combustion

� H2 has uses other than simple combustion

� CO2 can be captured at pressure

� Disadvantages

� Requires an ASU and a gasifier

� Methods in development (other than PSA)


Slide 7

Pre-Combustion Separation Methods

� Pressure Swing Adsorption

� Micro-Scale Filtration

� Amine Absorption

� Dense Membranes

� Ceramic

� Metallic

� Composite (e.g. Cermets)


Slide 8

Pressure Swing Adsorption

� Advantages

� Well-established commercially especially in natural gas systems and refineries

� Feed impurities largely stay with the raffinate (CO2 stream)

� Can produce fairly high purity H2

� Disadvantages

� Raffinate is at low pressure (typically near atmospheric)

– Essentially limited to one stage of WGS (less CO conversion & H2 recovery)

– Additional costs to compress the CO2 for sequestration

� Only 80-90% of H2 is recovered (remainder in raffinate)

� Only 1 stage of WGS (low pressure raffinate)

� Higher purity H2 product requires more energy (more freq. switching) and more H2 lost in CO2 raffinate

� Mechanically more complex – switching beds

� Higher energy usage than filters / membranes

� Higher capital cost


Slide 9

Micro-Porous Membranes

� Advantages

� Simple, no moving parts

� Retentate at high pressure

� Multiple stages of WGS possible

� Disadvantages

� Separation quality questionable

– CO2 in H2 product, H2 in raffinate

� H2 product at relatively low pressure

� Still in development

– Cost

– Fabricability

– Contaminant and steam tolerance


Slide 10

Dense Membranes

� Advantages

� Simple, no moving parts

� Pure H2 product

� Raffinate (CO2) at high pressure

� Enables multiples WGS stages

� Low cost (maybe)

� Disadvantages

� Low flux – large membrane area required

� Ceramic

– High operating temperatures (above WGS)

– Sealing between ceramic and metal

– Low allowable ∆P (mechanical strength)

� Metallic

– Low outlet H2 pressure (limited by embrittlement)

– Cost - Palladium (most common) is very expensive

– Contaminants (sulfur causes Pd4S)

� Still in development

Conceptual design of a commercial membrane unit capable of separating 25 tons per day of hydrogen. Sizing is based upon syngas at 1000 psig (69 bar), 450°C, 50 vol.% H2 in feed.

W ater-gas shift mixture entrance

Concentrated CO 2 exhaust

Closed end o f tubes

M embrane tubes

Hydrogenexit


Slide 11

Hydrogen Transport Across Eltron’s Membrane

H-HH-H

H-H

H-H

Layers ofHydrogen

DissociationCatalyst

HydrogenTransport

MembraneMaterial

H-HH H H H

H HH H

H

HydrogenDissociation

Diffusion of Hydrogen inDissociatedForm

Recombination and

Desorption of H2

HH

H-H

H-H


Slide 12

Eltron’s Layered Membrane vs. Thin Films

� Leaks – pinhole & other

� Syn gas comes through leaks in thin film

� Gas stops at the bulk membrane layer in Eltron’s HTM

� Performance

� Eltron’s HTM has very thin catalyst layers for higher flux

� Cost

� Catalyst layers on Eltron HTM are 0.1 micron or less

� Thin films are 5-10 microns thick


Slide 13

Planar Design (SOFCo)

SOFCo Planar Design(DE-FC26-OINT41145)

�Wafer panel length 2 m (6.55 ft)

�159 stacks

�590 tons per day of hydrogen (234 MMSCFD)

�FutureGen: Need to evaluate merits of tubular versus planar


Slide 14

Formed/Rolled Heads

Custom Flanges

Feed Gas

Retentate

High temp. valves

Packed

Unions

Purge/Sweep

Permeate

Distribution Header,

Anchored Membrane

Distribution Header,

Floating Press. Relief

Vent

Permeate

Figure 6: Low-Pressure Design

Tubular Designs (NORAM)


Slide 15

500N/AN/AN/APermeate Pressure (psi)

0.9>531Stability/Durability (years)

>99.99999.9999.595Hydrogen Purity (%)

YesYesYesYesCarbon Monoxide Tolerance

1,000800-1000400100∆P Operating Capability (psi)

<200<2505001000System Cost ($/ft2)

20 (early)202N/AS Tolerance (ppmv)

320-440250-500300-600400-700Operating Temperature (oC)

16015010050Flux (sccm/cm2/100 psi ∆∆∆∆P)

Current Eltron

Membrane

2015

Target

2010

Target

2005 TargetPerformance

Criteria

Progress Towards DOE FutureGen Targets


Slide 16

Water-Gas Shift Consideration

� Synthesis Gas (not just from coal) contains CO2, H2, CO and H2O

� Water-Gas Shift Reaction

CO + H2O ↔ CO2 + H2

� At equilibrium, outlet CO is well under 4%

� By using one or more WGS reactors in conjunction with a CO2/H2 separation system, almost all of the CO can be converted to more CO2 and H2

� WGS is mildly exothermic (generates heat)


Slide 17

Role of Hydrogen Separation Membranesin CO2 Sequestration

2352mvm.dsf

ParticulateRemovalSystem

CatalystGuardBeds

Water-Gas Shift

Reactor

40% H2 +CO2 + H2O

340-440°C1000 psi

H2 + CO

320-440°C1000 psi

Synthetic FuelsPetroleum RefiningFuel Cells

Electricity

H2O

Compress H2

435 psi

Steam320°C

1000 psi

H2 + CO

320°C1000 psi

Electricity

H2O

H2O

H2 + COSynthesis Gas

H2 + CO

1040°C1000 psi

SteamTurbine

1000 psiCO2

H2O

Slag Oil + GasRecovery

HeatExchanger

320°C1000 psi

320°C1000 psi

Steam

Oxygen

H2

CoalGasifier

>1040°C1000 psi

HydrogenTurbine

CoalSlurry

Oxygen

HydrogenSeparation

Unit

AirAirSeparation

Unit

N2

<400 psi

CO2 Sequestration Condense H2OCompress CO2 2700 psiCO2 Pipelines


Slide 18

WGS WGS WGS

H2

H2

H2 H2 H2 H2

H2 H2

H2 H2

Compr

Compr

5 psig

60 psig

200 psig

Compr

-10 psig

Steam

H2 to Fuel or Export

Synthesis Gas

Simplified FlowsheetStaged WGS / HTM System

Maximum H and CO Production22

CO2 to Sequestration

> 96% Recovery

1,000 psig300°C

950 psig400°C> 96% CO (ex H O)22

HTM1

HTM2

HTM3

HTM1

HTM2

HTM3

HTM1

HTM2

HTM3

HTMV


Slide 19

Process Issues Being Worked

� Contaminant handling

� Rejected on membrane surface

� Removal upstream of WGS/HTM system

� Integrated vs. staged WGS/HTM

� Stage optimization

� Recovery per stage (area vs. compression)

� Membrane configuration

� Tubular vs. planar

� Commercial scale catalyst application

� Residual H2 Handling

� Maximum recovery vs. Hi-P combustion

� Cost Comparison vs. PSA, post-combustion capture etc.


Slide 20

� In their 2005 book, the Carbon Capture Project team (BP, Chevron, Shell, Statoil, Norsk Hydro, ENI, Suncor and EnCana) stated that “the team believes that membrane reactors for hydrogen production have the potential for significant cost reduction and gave this technology its top priority.”

� Baseline – Post-combustion capture

� PSA – Estimated 30% cost reduction

� Dense membranes – 60% cost reduction

– (Prior to Eltron permeate pressure discovery)


Slide 21

Other Considerations

� HTM enables purity H2 production with CO2 capture

� Eltron believes it will be best-in-class for either.

� It doesn’t care whether the synthesis gas feedstock is from coal, biomass, petroleum coke, distillates, LPG, natural gas etc.

� Given the relative instability of gasifiers and the range of contaminants in coal, FutureGen is likely the most difficult application of HTM.

� Eltron is evaluating a number of other applications other than H2 separation from syn gas including dehydrogenation (on the inlet side) and other reactions involving H2 on the permeate side.


Slide 22

(Clever) Application in an IGCC Power Plant

Please see presentation by Bill Rollins of NovelEdge Technologies in session 49 of this conference titled “High Efficiency Coal Plant that Meets the DOE 2002 Goal”

Documents

Eltron Research & Development An Analysis of …...Eltron Research & Development An Analysis of Dense Hydrogen Membranes as a Means of Producing a CO 2 Rich Stream Consistent with