carbon capture, storage and utilisation technologies: a ... · carbon capture, storage and...

Carbon capture, storage and utilisation technologies: A critical analysis and comparison of their life cycle environmental impacts

Rosa Cuéllar-Franca and Adisa Azapagic

School of Chemical Engineering and Analytical Science The University of Manchester

LCA in CO2 Utilisation

4th March 2015 Sheffield, UK

The importance of LCA in CCS and CCU systems

• To avoid mitigating climate change at the expense of other environmental issues

• To avoid shifting the environmental burdens from one life cycle stage to another

Overview

• Life cycle environmental impacts of – CCS and – CCU

• Comparison of environmental impacts of CCS and CCU technologies

• Presentation based on: Cuellar-Franca, R and A. Azapagic (2015). Carbon capture, storage and utilisation technologies: A critical analysis and comparison of their life cycle environmental impacts. Journal of CO2 Utilization, 9, 82–102.

Different carbon capture, storage and utilisation options

Post-

conversion

capture

Adsorption by

solid

sorbents

Absorption by

chemical

solvents

Membrane

separation

Cryogenic

separation

Pressure/

vacuum swing

adsorption

Utilisation

options

Chemical

feedstock

Other

applications

Fuels

Mineral

carbonation

Enhanced oil

recovery (EOR)

Geological

storage

Ocean

storage

Absorption by

chemical

solvents

Absorption by

physical

solvents

Pre-

conversion

capture

Cement

industry

Energy sector

(fossil fuels)

Oil

refineries

Iron & steel

industry

Biogas

sweetening

Chemicals

sector

Combustion

in pure

oxygen

Chemical

looping

Chemical

looping

reforming

Storage

options

Oxy-fuel

combustion

capture

Capture

options

LCA studies on CCS

• LCA studies are mainly focused on CCS technologies for power plants – Pulverised coal – Integrated coal gasification combined cycle – Combined cycle gas turbine

• Variation in goal and scope – Comparison of different CCS technologies – Power plants with and without CCS – CCS vs renewable energy technologies

LCA studies on CCS

• Functional unit (unit of analysis) related to a unit of electricity generated

• System boundaries consistent across all studies

Power plant (CO2 source)

Power plant (CO2 source)

CO2 separation

and capture

CO2 separation

and capture

Geological storage -Depleted oil & gas field -Saline aquifer -Coal bed formation

Geological storage -Depleted oil & gas field -Saline aquifer -Coal bed formation

CO2 compression, transport and

injection

CO2 compression, transport and

injection

Ocean storage -Below the sea bed

Ocean storage -Below the sea bed

Fuel extraction and supply

Fuel extraction and supply

Infrastructure

Infrastructure

Post-conversion capture via chemical

absorption using MEA most studied method

Most studies considered

geological storage

Global warming potential of PC, CCGT and IGCC plants with CCS

0

200

400

600

800

1000

1200

1400

1600

No CCS Post-conversion Pre-conversion Oxy-fuelcombustion

GW

P (

kg

CO

2 e

q./

MW

h)

PC CCGT IGCC

R.M. Cuéllar-Franca, A. Azapagic/ Journal of CO2 Utilization 9 (2015) 82-102

(PC) Pulverised coal (CCGT) Combined cycle gas turbine (IGCC) Integrated coal gasification combined cycle

GWP of PC, IGCC and CCGT plants with CCS

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

1200

Infrastructure Fuel supply CO2 capture CO2compression,

transport,injection

Storage Power plantdirect

emissions

Total withCCS

Total withoutCCS

Avoidedcarbon

emissions

GW

P (

kg

CO

2 e

q./

MW

h)

PC IGCC CCGT


(PC) Pulverised coal (CCGT) Combined cycle gas turbine (IGCC) Integrated coal gasification combined cycle

Other environmental impacts of PC plants with and without post-conversion CCS

-250

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

2750

3000

AP

(g S

O2 e

q.)

AD

P x

0.0

1 (

kg S

b e

q.)

EP

x 1

0 (

kg

PO

4 e

q.)

OD

P x

10E

-8 (

kg R

-11

eq.)

HT

P (

kg

DC

B e

q.)

FA

ET

P x

0.1

(kg D

CB

eq.)

MA

ET

P x

10

00 (

kg D

CB

eq.)

TE

TP

x 0

.001

(kg D

CB

eq.)

PO

CP

x 1

0 (

kg

C2H

4 e

q.)

To

tal

imp

act/

MW

h

No CCS Koornneef et al. (2008) Nie et al. (2011)

Korre et al. (2009) Schreiber et al. (2009) Viebahn et al. (2007)

Pehnt and Henkel (2008)


(PC) Pulverised coal

LCA studies on CCU

• LCA studies on CCU technologies for – Power plants – Chemical plants

• CO2 utilisation options studied – Enhanced oil recovery (EOR) – Production of mineral carbonates – Chemicals – Biodiesel from microalgae

LCA studies on CCU

• System boundaries more or less consistent across all studies

CO2 separation

and capture

CO2 separation

and capture

CO2 transport

CO2 transport

CO2 compression

CO2 compression

Carbonates Chemical products

Extracted oil Biofuels

CO2 source

CO2 source

CO2 as a feedstock

CO2 as a feedstock

Mineral carbonation

of CO2

Mineral carbonation

of CO2

Injection of CO2 to mature oil well (EOR)

Injection of CO2 to mature oil well (EOR)

Microalgae cultivation

Microalgae cultivation

Post-conversion capture via chemical

absorption using MEA most studied method

LCA studies on CCU

• Functional unit varied across the studies – Related to the main product

• Electricity generated • Chemicals produced • Biodiesel produced • Extracted oil

– Amount of CO2 removed – Energy content in biodiesel – Distance travelled

GWP of mineral carbonation

-1000

-500

0

500

1000

1500

Power plantemissions

CO2 capture,compressionand transport

CO2sequestered

Total powerplant with

CO2 capture

Mineralcarbonation

Total CCU Avoided CO2

GW

P (

kg

CO

2 e

q./

t C

O2 r

em

oved

)


GWP of enhanced oil recovery

-1.0

-0.5

0.0

0.5

1.0

1.5

Mining andfuel supply

Power plantoperation

CO2 capture,compressionand transport

CO2 removed Total powerplant with

CO2 capture

EOR Total CCU Avoided CO2

GW

P (

t C

O2 e

q./

t C

O2 r

em

oved

)

Hertwich et al. (2008) Jaramillo et al. (2009)


GWP of other CCU options

• Utilising CO2 for production of dimethyl carbonate reduces GWP by 4.3 times compared to the conventional DMC process

• Capturing CO2 by microalgae to produce biodiesel has 2.5 times higher GWP than fossil diesel

GWP of CCS and CCU options

0.0

0.5

1.0

1.5

2.0

2.5

3.0

CCS CCU - carbonmineralisation

CCU - EOR CCU - biodieselfrom microalgae

CCU -production of

chemicals(DMC)x 100

GW

P (

t C

O2 e

q./

t C

O2 r

em

oved

)


Other environmental impacts of CCS and CCU

0

5

10

15

20

25

30

35

40

45

CCS CCU - EOR CCU -Chemicals

(DMC)

CCS CCU -Biodiesel

frommicroalgae

CCU -Chemicals

(DMC)

CCS CCU -Chemicals

(DMC)

CCS CCU -Biodiesel

frommicroalgae

CCU -Chemicals

(DMC)

AP x 10 (kg SO2 eq.) EP (kg PO4 eq.) ODP (mg R11 eq.) POCP (kg C2H4 eq.)

To

tal im

pa

ct

⸗ 115

To

tal im

pact/

t C

O2 r

em

oved


Conclusions

• CCS studies suggest that the GWP from power plants can be reduced by 63-82%

• Other environmental impacts are higher with than without CCS

• For CCU, CO2 savings depend largely on the utilisation option

• The average GWP of all CCS options is significantly lower than the GWP of any CCU options considered

Recommendations

• Specific guidelines for application of the LCA methodology to CCS and CCU technologies – Definition of system boundaries – Establishment of a standard functional unit

• Consideration of wider range of environmental impacts from CCS and CCU

• Consideration of different allocation methods

• Assessment of the uncertainty in the data and results

• Studies of different sources of CO2

Further information

Cuellar-Franca, R and A. Azapagic (2015). Carbon capture, storage and utilisation technologies: A critical analysis and comparison of their life cycle environmental impacts. Journal of CO2 Utilization, 9, 82–102.

Acknowledgement

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