Perspectives on the role and value of CCU in

climate change mitigation

Niall Mac Dowell Imperial College London

niall@imperial.ac.uk

@niallmacdowell

Key questions on CO2 capture and utilisation

1.What is it?

2.Why do we want it?

3.Will it mitigate climate change?

4.Is it likely to be cost effective?

5.Will it deliver CCS?

CCU archetypes: “catch and release”

Fossil carbon; coal, oil, gas..

C

C

S

CH3OH

H2

O2

>95%

CO2 CH3OH

400

ppmCO2

Energy flow

Mass flow

CCU archetypes: “two bites of the cherry”

Fossil carbon; coal, oil, gas..

CH3OH

H2

O2

>95%

CO2 CH3OH

400

ppmCO2

Energy flow

Mass flow

DAC

Stored CO2

C

C

S

CCU archetypes: “circular economy”

CH3OH CH3OH

400

ppmCO2

>95%

CO2

H2O

O2 H2 DAC

Energy flow

Mass flow

Why CCU?

• There are many reasons to “like” CCU:

1. C1 chemistry

2. Applied catalysis

3. Energy storage

4. Producing and using renewable energy

5. More environmentally benign chemical processes

6. Combatting climate change

• Many reasons to like CCU, climate change mitigation is not “it”

0

10

20

30

40

50

60

70

80

90

100

1960 1980 2000 2020 2040 2060

Gt C

O2/y

r

Year

BP Data

High (2.8%/yr)

Med (2.38%/yr)

Low (1.96%/yr)

6DS (1.4%)

2DS

Quantifying the mitigation challenge

2DS

6DS

Last 5 years

Last 15 years

Average since

1965

BP Statistical review, 2014, IEA ETP 2012 and 2014

Quantifying the mitigation challenge (MC)

0

10

20

30

40

50

60

1960 2010 2060

Gt C

O2/y

r

Year

BP Data

6DS (1.4%)

2DS

• MC ≥800 GtCO2 by 2050

• IEA suggests 14 – 40% by CCS

• Implies > 120GtCO2 sequestered by CCS by 2050

• Equivalent to ~ 3.5 years of total global emissions today

• 1% of MC ≈ 8 – 10 GtCO2 by 2050

MC

BP Statistical review, 2014, IEA ETP 2012 and 2014

What could CO2 Conversion contribute?

CO2 balance of CO2-EOR

Conventional EOR1

Advanced EOR1

Max Storage EOR1

~ 3.33bbloilProd

~ 1.67bbloilProd

~ 1.1bbloilProd

~ 1.43tCO2

em

~ 0.72tCO2

em

~ 0.48tCO2

em

1 tCO2

inj

1 tCO2

inj

1 tCO2

inj

0.43tCO2

Net

-0.28tCO2

Net

-0.52tCO2

Net

1: IEA, “Storing CO2 through Enhanced Oil Recovery”, 2015, 2: https://www.epa.gov/energy/ghg-equivalencies-calculator-calculations-and-references 3: Mui, et al., “GHG Emission Factors for High Carbon Intensity Crude Oils”, NRDC, 2010

Must consider what gets displaced, e.g., unconventional oil with a CO2 intensity of 108 – 173% of conventional oil3

What could CO2-EOR contribute?

CO2 EOR Oil Miscible CO2 Oil

Ratio Upper

bound Lower

bound

Recovery Basin (tonnes/Bbl

) CO2 Stored CO2

Stored Region Name (MMBO) Count (Gt) (Gt)

Asia Pacific 18,376 6 0.27 5 2.76 Central and South America 31,697 6 0.32 10.1 4.75 Europe 16,312 2 0.29 4.7 2.45 Former Soviet Union 78,715 6 0.27 21.6 11.81 Middle East and North

Africa 230,640 11 0.3 70.1 34.60 North America/Non-U.S. 18,080 3 0.33 5.9 2.71 United States 60,204 14 0.29 17.2 9.03 South Asia - 0 N/A - Sub-Saharan Africa and

Antarctica 14,505 2 0.3 4.4 2.18 Total 468,529 50 0.296 139 70

IEA Greenhouse Gas R&D Programme, CO2 Storage in Depleted Oilfields: Global Application Criteria for Carbon Dioxide Enhanced Oil Recovery, Report IEA/CON/08/155

How well matched are the sources and sinks?

Mac Dowell, et al., Nature Climate Change, 2017

How big might CO2-EOR grow?

Nothing in life is free

• Low carbon energy – Intermittent renewable energy (poor capacity factor/credit)

• Wind $63.7 – 157.4/MWh1

• Solar $85 – 242/MWh1

– Geothermal energy (not widely available)

– Geothermal energy $46.5/MWh1

• Low carbon/renewable H2 production – CAPEX ~ $1,100 – 1,200/kgH2.day for a 1,000 kgH2/day unit2

– OPEX ~ $2.67/kgH2 (geothermal), $3.7 – 10.69/kgH2 (on/offshore wind) 2,3

– For comparison, H2 production via SMR ~ $1-2/kg as a function of CH4 prices4

• Available CO2 – Cost $60 – 100/tCO2 for CCS1, $600 – 1,000/tCO2 for DAC5

1: www.eia.gov/forecasts/aeo/electricity_generation.cfm

2: NREL, “Current (2009) State-of-the-Art Hydrogen Production Cost Estimate Using Water Electrolysis” 3: I E A/H I A T A S K 2 5 : High Temperature Hydrogen Productions Process: Alkaline Electrolysis

4: NRES, “Hydrogen Supply: Cost Estimate for Hydrogen Pathways - Scoping Analysis”, 2002 5: House, PNAS, 2011, Ranjan, Energy Procedia, 2011

CO2 and energy balance of CO2-MeOH

Catalytic hydrogenation of CO2

1 tCH3OH

0.12 tCO2/tCH3OH

1.48 tCO2/tCH3OH

0.2 tH2/tCH3OH

1.82 tH2O/tCH3OH

40.6 GJel/tCH3OH 3.0 GJth/tCH3OH

1: É.S. Van-Dal, C. Bouallou, Journal of Cleaner Production, 2013, 57, 38 – 45 2: Atlason and Unnthorsson, "Ideal EROI (energy return on investment) deepens the understanding of energy systems". Energy, 2014, 67, 241–45.

3: Hall, et al., "EROI of different fuels and the implications for society". Energy Policy, 2013, 64, 141–52.

A fuel or energy must have an EROEI ratio of at least 3:1 to be considered realistically viable as a prominent fuel or energy source2,3

EROEI = Energy Delivered

Energy Required to Deliver that Energy= 0.451

CO2-MeOH as a gasoline substitute?

• Can also compare MeOH and gasoline (petrol) on an energy basis (potentially controversial)

All data for energy density, CO2 intensity, gal/bbl, etc.from: https://www.epa.gov/energy/ghg-equivalencies-calculator-calculations-and-references, https://www.eia.gov/tools/faqs/faq.cfm?id=327&t=9 and http://www.eia.gov/tools/faqs/faq.cfm?id=307&t=11

1 bblOil 19 Galgasoline/bbloil = 53.22 kggasoline/bbloil

2,469 MJgasoline/bbloil 164.46 kgCO2/bbloil

125.36 kgMeOH/bbloil 188.04* kgCO2/bbleq

• *188.04kgCO2/bbleq = 125.36 kgMeOH/bbleq(1.38 kgCO2/kgMeOH) + 0.12(125.36) kgCO2/kgMeOH

• Using CO2-derived MeOH for fuel could result in as much as 114% of the CO2 that would otherwise be associated with gasoline/petrol for an equivalent transport service

CCU is fine, with Direct Air Capture…if you can afford it…

Cost of DAC: $500/tCO2 < $DAC <$1,000/tCO2

House, et al., PNAS, 2011

Cost effectiveness of CO2 to methanol?

CO2 utilisation ≠ CO2 sequestration

Process Lifetime of storage

Urea < 6 months

Methanol < 6 months

Inorganic Carbonates Decades

Organic Carbonates Decades

Polyurethanes Decades

Technological Days to years

Food and Drink Days to years

Geological

sequestration

Centuries

• The storage of CO2 is typically short term – especially for largest sinks; methanol and urea. • “Short term” storage will not have significant climate benefit • “Short term” is anything less than ~ 1,000 years

Data from Wilcox, Carbon Capture

Will CCU deliver CCS?

• In the US, CO2-EOR, “maybe”

• CO2 transport and injection infrastructure is available, and written off

• The challenge is capturing CO2 at an attractive cost at current oil prices

• Tax incentives via CO2 tax credits likely to remain important

• In the UK/EU, “no”

• There is no CO2 transport infrastructure – this needs to be deployed

• The lack of infrastructure adds substantial cross-chain risk to any CCS

• Cross-chain risk is not currently “bankable”

• CCS infrastructure requires projects on the order of 10 Mt/yr for economies of scale

• End-to-end saline aquifer storage projects at > 10 Mt/yr scale are required to

“derisk” CCS

• This will lead to material cost reductions, kt/yr slip-stream projects will not

Will CCU deliver CCS?

Some conclusions

• The IEA 2DS involves mitigating > 800 GtCO2 to 2050

• CO2-EOR can deliver 4.5% of this – perhaps up to 8 – 10%

• CO2 conversion could deliver 0.49 – 0.6%

• CCU will not deliver CCS – kt vs. Mt scale projects

• CCU bottleneck: the availability of affordable, renewable H2

• Niche opportunities: plastics (DREAM process) waste carbonation (Carbon8), cement curing (Solidia technologies)

• Beware of unintended consequences, e.g., CO2 to MeOH emits 114% of the CO2 emissions associated with gasoline..?

• CCU likely a distraction from climate change mitigation

If I have “surplus electricity”, what should I do?

Sternberg and Bardow, Energy and Environmental Science, 2015

Nothing in life is free

• Low carbon energy

– Intermittent renewable energy = poor capacity factor/credit

• Wind (CF: 36 – 38%) $73.6 – 196.9/MWh1,

• Solar (CF: 20 – 25%) $125.3 – 239.7/MWh1

– Geothermal energy is not widely available – Iceland’s CRI example is quite unique here

• Geothermal energy (CF: 92%) $47.8/MWh1,

• Low carbon/renewable H2 production

– Alkaline water electrolysis is mature, operating on scale, e.g., 3,000 kg/hr in Egypt

– Not well suited to intermittent operation (this is improving)

– CAPEX ~ $1,100 – 1,200/kgH2.day for a 1,000 kgH2/day unit2

– OPEX ~ $2.67/kgH2 (geothermal), $3.7/kgH2 (onshore wind) $10.69/kgH2 (offshore wind) with current SOTA performance2,3

– For comparison, H2 production via SMR ~ $1-2/kg as a function of CH4 prices4

• Available CO2

– Cost $60 – 100/tCO2 for CCS, $600 – 1,000/tCO2 for Direct Air Capture

1: www.eia.gov/forecasts/aeo/electricity_generation.cfm

2: NREL, “Current (2009) State-of-the-Art Hydrogen Production Cost Estimate Using Water Electrolysis” 3: I E A/H I A T A S K 2 5 : High Temperature Hydrogen Productions Process: Alkaline Electrolysis

4: NRES, “Hydrogen Supply: Cost Estimate for Hydrogen Pathways - Scoping Analysis”, 2002

How is the UK system likely to evolve?

Mac Dowell and Staffell, Int. J. GHG Con., 2016

Surplus renewable electricity?

Mac Dowell and Staffell, Int. J. GHG Con., 2016