Carbon Capture - Carbon Mitigation Initiative · PDF fileCarbon Capture Robert H. Williams ... • Continued development of Aspen Plus and GS models for ... IGCC Electricity with CO2

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Carbon Capture

Robert H. WilliamsH2/Electricity Economy Group

Princeton Environmental Institute

Second Annual CMI Meeting14 January 2002

Princeton University

Activities• H2/electricity production

– Membrane reactors– Conventional technology– Making H2 with co-capture/storage of sulfur (H2S or

SO2) and CO2

– Fuel Grade H2

• H2/CO2 infrastructure• H2 utilization technologies• Princeton-Tsinghua collaboration on low

emission energy technologies for China

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H2/CO2 Infrastructure StudiesGoal: Examine possible transition strategies to a future energy system based on production of H2 and electricity from fossil fuels with capture and underground storage of CO2. This involves development of two new pipeline infrastructures, one for H2 distribution and one for CO2 disposal.

Model entire system; multi-decade time frame• Develop engineering/economic models for components: fossil energy complexes, CO2 pipelines, CO2 sequestration site, H2 pipeline distribution, H2

demand. •Use a variety of analytic and simulation tools to understand performance and economics of entire system. •Explore use of operations research methods to co-optimize H2 and CO2pipeline networks with multiple fossil energy complexes, storage sites, and energy demand centers. •Carry out one or more case studies of regional H2/CO2 infrastructure development using GIS data as input.

New NETL and NREL contracts to support for PEI studies of H2/CO2

infrastructure (J. Ogden, P.I., R. Williams, E. Larson, E. Kaijuka, W. Wang)

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Coal polygeneration – general scheme

Gasification and clean up Synthesis

H2

coal

Gas Turbine CC

methanol

ElectricitySeparation

CO2

MethanolDMEF-T liquids

Water Gas Shift

ASU air

oxygen Town gas

Carbonylation Acetic acidCO

enhanced resource recoveryor aquifer sequestration CO2

CO + H2O = H2 + CO2

Separation

0.85 CO + 0.15 CO2

+ 0.68 H2

H2O

O2

Polygeneration at Princeton during 2002• Use Aspen to develop and verify process sub-component models:

– coal gasification island– kinetically-modeled reactor for liquid-phase and gas-phase synthesis of

methanol (MeOH) and dimethyl ether (DME)– downstream separation of synthesis products (DME, MeOH, CO2, CO, etc.)– gas turbine/steam turbine combined cycle– methanol carbonylation for acetic acid production

• Develop full process flowsheets for coal conversion to– MeOH and DME, with electricity co-production (using pinch analysis to

assist process heat integration).• Once-through and recycle liquid-phase synthesis• Once-through and recycle gas-phase synthesis

– DME, acetic acid, and electricity tri-generation (in progress).• Process economics (not yet complete)

– Literature review– Beginning to learn ICARUS (ASPEN costing package)– Consult with industry experts (Bob Moore, BP Chemicals, others)– Develop detailed cost database and economic analysis

• Other– Initiated work on biomass-based polygeneration

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H2/ELECTRICITY PRODUCTION ANALYSES

• Continued development of Aspen Plus and GS models for applications to H2 + electricity systems

• Major expansion of data bases for performance/costs of electricity/H2system components

• Expanded modeling of H2 separation membrane reactors—aimed at predicting relevant heat, mass balances and making cost estimates

• New focus on wide range of configurations for producing H2 and electricity from coal using conventional technologies for separation of gases

Benchmark: IGCC Electricity with CO2 Capture

• Cost: 6.4 ¢/kWh (at carbon tax of 93 $/tonne C), efficiency: 34.8% (HHV). (70 bar gasifier with quench cooling; plant scale: 368 MWe)

GHGT-6 conv. electricity, CO2 seq. (9-25-02)

Saturatedsteam

CO-richraw syngas

N2 for (NOx control)

H2- andCO2-richsyngas

Heat recoverysteam generator

CO2-leanexhaust

gases

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

95%O2

Steamturbine

Gas turbineAir

Turbineexhaust

SupercriticalCO2 to storage

CO2 drying +compression

High temp.WGS

reactor

Low temp.WGS

reactorLean/richsolvent

CO2physical

absorption

Solventregeneration

Lean/richsolvent

H2Sphysical

absorption

Regeneration,Claus, SCOT

H2-richsyngas

Syngasexpander

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H2 Production: Add H2 Purification/Separation

• Replace syngas expander with PSA and purge gas compressor.

GHGT-6 conv. electricity, CO2 seq. (9-25-02-a)

Saturatedsteam

CO-richraw syngas




CO2-leanexhaust

gases

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

95%O2

Steamturbine

Gas turbineAir

Turbineexhaust



High temp.WGS

reactor

Low temp.WGS


CO2physical

absorption

Solventregeneration

Lean/richsolvent

H2Sphysical

absorption


H2-richsyngas

Syngasexpander

Conventional H2 Production with CO2 Capture

• H2 cost: 7.5 $/GJ (HHV) (at carbon tax of 38 $/tonne C, electricity 4.6 ¢/kWh ). [70 bar gasifier with quench cooling; plant scale: 1210 MWth H2 (HHV)]

GHGT-6 conv. hydrogen, CO2 seq. (9-25-02)

Saturatedsteam

CO-richraw syngas

High purityH2 product




CO2-leanexhaust

gases

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

95%O2

Steamturbine

Gas turbineAir

Pressureswing

adsorption

Purgegas

Turbineexhaust


High temp.WGS

reactor

Low temp.WGS


CO2physical

absorption

Solventregeneration

Lean/richsolvent

H2Sphysical

absorption



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Capture (and Co-store) H2S with CO2

• Remove the traditional acid gas recovery (AGR) unit.

GHGT-6 conv. hydrogen, CO2 seq. (9-25-02-a)

Saturatedsteam

CO-richraw syngas





CO2-leanexhaust

gases

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

95%O2

Steamturbine

Gas turbineAir

Pressureswing

adsorption

Purgegas

Turbineexhaust


High temp.WGS

reactor

Low temp.WGS


CO2physical

absorption

Solventregeneration

Lean/richsolvent

H2Sphysical

absorption



Conventional H2 Production with CO2/H2S Capture

• Resulting system is simpler and cheaper.

GHGT-6 conv. hydrogen, co-seq. (9-25-02).FH10

Saturatedsteam

CO-richraw syngas



H2- andCO2-rich

syngas


CO2-leanexhaust

gases

High temp.WGS

reactor

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

Low temp.WGS

reactor

CO2/H2Sphysical

absorption

Solventregeneration

Lean/richsolvent

95%O2

Steamturbine

Gas turbineAir

Pressureswing

adsorption

Purgegas

Turbineexhaust

CO2 + H2Sto storage

CO2/H2Sdrying andcompression

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Produce “ Fuel Grade” H2 with CO2/H2S Capture

• Remove the PSA and gas turbine; smaller steam cycle.

GHGT-6 conv. hydrogen, co-seq. (9-25-02-a).FH10

Saturatedsteam

CO-richraw syngas



H2- andCO2-rich

syngas


CO2-leanexhaust

gases

High temp.WGS

reactor

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

Low temp.WGS

reactor

CO2/H2Sphysical

absorption

Solventregeneration

Lean/richsolvent

95%O2

Steamturbine

Gas turbineAir

Pressureswing

adsorption

Purgegas

CO2 + H2Sto storage


“ Fuel Grade” (~93% pure) H2 with CO2/H2S Capture

• Simpler, less expensive plant. No novel technology needed.

GHGT-6 Fuel grade H2, co-seq. (9-25-02)

Saturatedsteam

CO-richraw syngas Low purity

H2 product(~93% pure)

N2

H2- andCO2-rich

syngas


CO2-leanexhaust

gases

High temp.WGS

reactor

Quench +scrubber

Air Airseparation

unit

Coalslurry O2-blown

coalgasifier

Low temp.WGS

reactor

CO2/H2Sphysical

absorption

Solventregeneration

Lean/richsolvent

95%O2

Steamturbine

CO2 + H2Sto storage


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• Incremental cost for CO2 capture is less for hydrogen than electricity because much of the equipment is already needed for a H2 plant.

Breakdown of Incremental Capital Cost for CO2 Capture

37%

36%

24%

3%

WGS reactors, heat exchangers

Selexol CO 2

absorption, and stripping

CO 2 drying, compression

Other

Coal IGCC(1326 → 1737 $/kW e )

100%

CO 2 drying, compression

H 2 from Coal(706 → 742 $/kW th H 2 HHV)

• Carbon tax needed to induce CO2 storage is extremely high.

• NGCC with CO2 capture is not considered further.

Economics of NGCC with Carbon Storage

3

4

5

6

7

0 50 100 150 200 250 300 350

Carbon Tax ($/tonne C)

Ele

ctric

ity C

ost (

¢/kW

h)

"Crossover point"for CO2 storage(292 $/tonne Cat 3.0 $/GJ NG)

NGCC withCO2 capture

NGCC withCO2 venting

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• Tax needed to induce CO2 storage in coal IGCC is much lower than NGCC.

• But, how does coal IGCC+CO2 storage compete with NGCC+CO2 venting...

Economics of Coal IGCC with Carbon Storage

4.5

5.0

5.5

6.0

6.5

7.0

0 20 40 60 80 100 120


Ele

ctric

ity C

ost (

¢/kW

h)

CO2 storage crossover:(93 $/tonne C)

Coal IGCC withCO2 storage

Coal IGCC withCO2 venting

• In addition to the carbon tax, the NG price must exceed ~6 $/GJ for coal IGCC+CO2 storage (...for any electricity+CO2 storage) to be economical!

The “Breakeven NG Price” to Induce CO2 Storage

4.5

5.0

5.5

6.0

6.5

7.0

0 20 40 60 80 100 120


Ele

ctric

ity C

ost (

¢/kW

h)

CO2 storage crossover:(93 $/tonne C,5.9 $/GJ NG)




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• Co-storage reduces both the crossover carbon tax and breakeven NG price somewhat, but the barrier to carbon storage remains quite high.

The Economics of H2S-CO2 Co-Storage

4.5

5.0

5.5

6.0

6.5

7.0

0 20 40 60 80 100 120


Ele

ctric

ity C

ost (

¢/kW

h)

Co-storage crossover:(72 $/tonne C,5.6 $/GJ NG)



Coal IGCC withH2S-CO2 co-storage

• Without CO2 storage, coal IGCC competes with NGCC at NG~4.5 $/GJ; the breakeven NG price rises with carbon tax due to coal’s high C content.

• Above the crossover tax, CO2 storage plants out-compete CO2 venting plants.

Breakeven NG Prices vs. Carbon Tax

4.5

5.0

5.5

6.0

0 20 40 60 80 100 120


Bre

akev

en N

G P

rice

($/G

J H

HV

)

Coal IGCC withH2S-CO2 co-storage



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• Both the carbon tax and breakeven NG price needed to induce coal H2 with CO2 storage are much lower than those for electric power.

• Industrial H2 from coal might be the earliest CO2 storage opportunity.

Economics of H2 from Coal with Carbon Storage

6.0

6.5

7.0

7.5

8.0

8.5

9.0

0 20 40 60 80 100 120


Hyd

roge

n C

ost (

$/G

J, H

HV

)

CO2 storage crossover (38 $/tonne C,4.1 $/GJ NG,

4.6 ¢/kWh NGCC)

H2 from coal with

CO2 storage

H2 from coal with

CO2 venting

H2 from NG with

CO2 venting

H2 from NG with

CO2 storage

• H2S-CO2 co-storage further reduces both the crossover carbon tax and breakeven NG price.

Economics of H2 from Coal with H2S-CO2 Co-Storage

6.0

6.5

7.0

7.5

8.0

8.5

9.0

0 20 40 60 80 100 120


Hyd

roge

n C

ost (

$/G

J, H

HV

)

Co-storage crossover (19 $/tonne C,3.9 $/GJ NG,

4.3 ¢/kWh NGCC)

H2 from NG with

CO2 storage

H2 from NG with

CO2 venting

H2 from coal with

CO2 venting

H2 from coal with

H2S-CO2 co-storage

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• Breakeven NG prices for coal H2 mirror those for IGCC (but are lower).

Breakeven NG Prices vs. Carbon Tax

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

0 20 40 60 80 100 120


Bre

akev

en N

G P

rice

($/G

J H

HV

)

CO2 venting

CO2 storage

H2S-CO2 co-storage

Coal IGCC:

CO2 venting

CO2 storage

H2S-CO2 co-storage

H 2 from Coal:

• Profits for DEC if revenues for sale of credits > capture cost + storage cost

Cap and Trade at Level of Secondary Energy Providers

DecarbonizingEnergyCompany (DEC)

Payments for CO2 Storage(pipe transport, wells,surface facilities)

$

Revenue fromSale of Credits forEmissions Avoided

$

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Plant-Gate CO2 Costs with CO2 Capture

24204 t/h1000 MWH2NG H2 (store)

0.59549 t/h1210 MWH2Coal H2 (co-store)

5.6549 t/h1210 MWH2Coal H2 (store)

11301 t/h379 MWeCGCC (co-store)

15301 t/h379 MWeCGCC (store)

33335 t/h367 MWeCoal UCS (store)

58118 t/h311 MWeNGCC (store)

Plant-gate

CO2 cost ($/t)

CO2 disposal rate

Plant outputPlant type

Strategic Findings for Power Generation

• CGCC favored technology for new coal power plants in climate-constrained world

• For CGCC, worthwhile to capture/store carbon @ CT ~ $100/tC << than required to decarbonize NGCC

• Still, primary energy and generation cost penalties are significant for CGCC w/capture/storage (~ 18-20% and 36-40%, respectively)

• Not urgent to decarbonize new NGCC plants (w/venting, emissions < ½ for CGCC)

• At CT ~ $100/tC, CGCC not competitive with NGCC/venting—until PNG

�$6/GJ

• Competing @ PNG =$3/GJ-$4/GJ � reducing CGCC capital cost w/capture/storage 35%-20%

• Severe climate policy constraint � shift to NG at expense of coal in power markets

• Mitigating factors: – Higher PNG as result of shift to NG– Enhanced resource recovery opportunities for CO2 captured at CGCC plants

• Potential loss of coal energy infrastructure � deleterious long-term impact because of coal’s promise in serving H2 markets

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Strategic Findings for Hydrogen

• As for electricity, needed (CT)coal H2 << (CT)NG H2 for inducing capture/storage

• Unlike electricity, good prospects that coal H2 w/capture/storage competitive with NG H2 w/venting for PNG ~ $3.5-$4.0/GJ

• Breakeven CT especially low for co-storage option (< $20/tC)

• In combustion applications, fuel-grade H2 adequate—less costly than high-purity H2

• In climate-constrained world (e.g., CT ~ $100/tC) fuel-grade coal H2 w/capture/storage plausibly competitive with NG in industrial markets in 20-25 y

• Though significant markets for H2 as energy carrier will not open up for 15-20 y, making H2 via gasification of petroleum residuals or coal at chemical plants, refineries � low cost CO2 source during next 2 decades for CO2 storage demos

• Though making H2 best (long-term) opportunity for coal in energy markets, transition to coal H2 difficult because of market threat to coal power industry from NG in early years of transition to low C energy economy

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Carbon Capture - Carbon Mitigation Initiative · PDF fileCarbon Capture Robert H. Williams ... • Continued development of Aspen Plus and GS models for ... IGCC Electricity with CO2