1. Future Fossil Fuel Usage &
Carbon Capture Technologies
Dr Paul Fennell
Department of Chemical Engineering and Chemical Technology, ICL

2. Summary
(1)CCS is not a synonym for clean coal
(2) There is an urgent need for accelerating full-scale
deployment
(3)There are major non-technical barriers
(4)There is a need to reduce the cost of capture
(5) New technologies must use basic engineering / lifecycle analysis to
demonstrate feasibility. This should be done before public money
is spent.

3. Questions...
What is CCS?
What are the barriers to capture?
What are the barriers to storage?
What are the overall barriers for the technology?

4. Why CCS?
CCS, alongside increased renewable sources, energy efficiency , nuclear
and lifestyle changes, is a critical to mitigate against climate change
Today all major economies
are underpinned by the
use of fossil fuels
Figure: CO2 emissions from
the combustion of fossil fuels,
excluding use in cement
industry
Boden T, Marland G Andres RJ. Carbon
Dioxide Information Analysis Centre
Oak Ridge National Laboratory, Oak
Ridge, Tennessee

5. Space in the the atmosphere in shorter supplythan fossil fuels
Carbon in atmosphere invs. carbon in fossil resources
Space in atmosphere isis shorter supply than fossil fuels
‘Unconventional oil’ includes oil sands and oil shales.
Unconventional gas’ includes coal bed methane, deep geopressured gas etc.
but not a possible 12,000 GtC from gas hydrates.
CARBON
IN CARBON THAT CAN BE
EMITTED TO
FOSSIL
ATMOSPHERE
FUELS
1990-2100
Basic data from IPCC 3rd assessment report

6. “ What is
CCS? ”
&
“ Why CCS is
not just a
synonym for
clean coal? ”

7. Technology options
post-combustion
power plant
air boiler, electricity, heat
fluidised
coal, gas and/or bed, N2
flue CO2
biomass industrial capture CO2
furnace gas
pre-combustion gas or oil
air, O2 CO2 high-pressure/
reformer CO2 electricity, high-purity
CO CO2 CH4
gasifier CH4 heat and/ CO2 for
CH4 shift capture H2
coal and/or H2 or H2 transportation
H2 reactor
biomass CO2 & storage
steam
oxy-fuel N2 power plant
boiler,
air fluidised electricity, heat
air O2
separation bed, CO2
unit industrial
coal, gas and/or furnace
biomass

8. CO2 capture technology overview
Pre-combustion
• partially oxidise the fuel to CO(2) and H2, separate them, and burn
the H2 in a (modified) gas turbine or fuel cell.
– Integrated Gasification Combined Cycle
– Chemical Looping Combustion
– ZECA process
Post-combustion
• Burn the fuel as usual in a (more-or-less) unmodified power plant.
• Add on a separate separation unit to remove CO2.
– Solvent Scrubbing
– Calcium looping
– Chemical Looping Combustion (alternate schemes)
Oxyfuel
• Burn the fuel in a mixure of pure O2 and recycled flue gas (to
moderate the temperature)

9. Post-combustion capture
‘End of pipe technology’,
can be retrofitted
Heat input for
regeneration of
solvent accounts
for decrease in
process /cost
efficiency
http://www.bellona.org/imagearchives/

10. Post-combustion capture
Closest to market technology:
Amine (MEA) Scrubbing

11. MEA scrubbing
• CO2 – rich gas is
exposed to MEA (15 –
30 wt. %) in a scrubbing
column, at around 55oC,
at a pressure of 1 bar.
• The loading of CO2 at
the exit of the column is
around 0.4 mol CO2 /
mol MEA.
• The CO2 is then
removed from the MEA
by boiling (at a pressure
of ~ 2 bar and a
temperature of ~120oC).
Loading = 0.15 .

12. Capturing the CO2 from the
power station has to reduce
its efficiency, relative to a
non- capture power station.
Thus, there are two costs
for CO2. The cost for CO2
captured (CC), and the cost
for CO2 avoided (CA).
The costs are related by the
fractional efficiency penalty
(EP).
CC = CA (1 – EP)
Thus, the capture cost is
always lower than the cost
for avoidance.

13. MEA scrubbing
Advantages
(i) Industrial experience – although much smaller scale
(ii) Known costs (?)
(iii) Post combustion method requires minimal changes to
the power station and suitable for retrofit (applicable to
other post-combustion methods)
Disadvantages/technical challenges
(i) Corrosion of equipment in the presence of O2 and other
impurities
(ii) High solvent degradation rates due to reaction with
oxygenated impurities
(iii) High energy requirements
(iv) Potential emissions of solvent to the environment
(v) Very large equipment required due to the huge volumes
of flue gas

14. Post-combustion carbonate looping
E.g. Shimizu et al, 1999

15. Post-combustion carbonate looping
Advantages
(i) sorbent derived from cheap and abundant natural limestone
(ii) relatively low efficiency penalty
(iii) synergy with cement production
(iv) technology proven on medium scale plant
Disadvantages
(i) deactivation, particularly in the presence of sulphur,
(can be reactivated, but increases plant complexity)
strategies exist to reduce deactivation
(ii) produces hot CO2 – wastes energy unless the system is
pressurized
(iii) particle attrition
EU CaOling project – first of a kind demonstration (2 MW).

16. Re-use spent sorbent in cement plant
kiln/cooler/
grinder
raw meal cement

17. Cement production using spent sorbent
3 kW spouted bed reactor CaO+SiO2+Al2O3+Fe2O3
ground, mixed and fired at 1450 °C
•This work used ‘pure’ oxides instead of typical raw materials (e.g. sand/clay) to
allows any change in the concentration of trace elements in the sorbent to be
measured
Dean et al. Energy and Environmental Science , 2011

18. Technology readiness level
1.7 MWth pilot taking slip
stream from the Hunosa 50
MWe CFB coal power
plant,"La Pereda“, Spain

19. Technology options
post-combustion
power plant
air boiler, electricity, heat
fluidised
coal, gas and/or bed, N2
flue CO2
biomass industrial capture CO2
furnace gas
pre-combustion gas or oil
air, O2 CO2 high-pressure/
reformer CO2 electricity, high-purity
CO CO2 CH4
gasifier CH4 heat and/ CO2 for
CH4 shift capture H2
coal and/or H2 or H2 transportation
H2 reactor
biomass CO2 & storage
steam
oxy-fuel N2 power plant
boiler,
air fluidised electricity, heat
air O2
separation bed, CO2
unit industrial
coal, gas and/or furnace
biomass

20. Pre-combustion capture
Integrated gasification combined cycle (IGCC)

21. Key chemical reactions
Gasification
fuel + O2/H2O/CO2 → H2,CO2,CO,CH4 + char + tar
Shift
CO + H2O ↔ CO2 + H2
Exothermic, conducted over a Ni catalyst
(poisoned by sulphur), pressure independent
Reforming
CH4 + 2 H2O ↔ CO + 3 H2
Endothermic, pressure sensitive, i.e. higher
pressure enhances methanation
These reactions lead to a H2-rich fuel gas,
CO2can be separated from this gas mixture

22. H2, H2
CO2, CH4
CH4, CO
CO
CCS Emissions equivalent to natural gas
Increasing cost and decreasing CO2
gasifier fired power station
CO2
H2, H2, H2,
CO2, CO2, CH4
CH4, CH4
CO
gasifier Shift CCS H2 rich fuel gas
“Clean”
H2
stream
CO + H2O → CO2 +H2 CO2
for FC
H2, H2, H2,
CO2,
H2
CO, CO2
CH4, CO2
CO
gasifier Reform Shift CCS
CH4 + 2 H2O → CO2 +4 H2
CO2
CO + H2O → CO2 +H2

23. Pre-combustion capture
Extra steam
(or water quench)
Jon Gibbins, Imperial College London, New Europe, New
Energy. Oxford, 27 Sep 2006; IEA GHG www.ieagreen.co.uk

24. FutureGen – $ 1.5 billion US clean coal concept

25. www.fossil.energy.gov/programs/powersystems/futuregen/

26. FutureGen timeline

27. Oxyfuel

28. Oxyfuel

29. Oxy-fuel
Advantages
(i) Technology suitable for retrofit (burners)
(ii) Comparatively simple
Disadvantages/ technical challenges
(i) Leaks (air inwards reduce purity)
(ii) Pure O2 (pneumatic conveying difficult)
(iii) Burner redesign (high CO2 makes flame properties different)
(iv) Safety concerns
(v) CO2 purity (?)
(vi) O2 produced using air liquefaction is energy intensive and
extremely costly

30. Schwartze Pumpe
30 MWe test
facility

31. Background
Chemical Looping
• Chemical Looping Combustion – Richter and
Knoche (1983), Ishida et al (1987)
(CO, H2) • Thermal efficiency (Power stations)
N2, Unreacted O2 CO2, H2O
• Advantages:
(H2)
• Efficient and low cost fuel combustion
MeO • Facilitates CO2 Separation (H2O (l)↓)
• Fuel Reactor (Mainly Endothermic)
Air Qo Fuel
• (2n+m)MeO + CnH2m ⇒ (2n+m)Me + mH2O +
Heat reactor reactor
nCO2 (Complete oxidation)
(Re- (Reformer)
Generator) Me
• (n)MeO + CnH2m ⇒ (n)Me + ((½)m)H2 + nCO
(Partial oxidation)
Air Fossil Fuel • Air Reactor (Exothermic)
(H2O) (H2O) • Me + ½O2 ⇔MeO
(Me + H2O ⇔ MeO + H2)

32. Chemical Looping Combustion
Thousands of hours running
98 % Fuel Conversion
99.7 % CO2 capture
Low attrition
Controllable, and Scalable
Photograph courtesy of A.
Lyngfelt, Chalmers U.

33. SCALE-UP & DEMONSTRATION
Chalmers University 100 kW th 2011
Darmstadt 1 MW pilot plant
(Courtesy TU Darmstadt)

34. Summary of Chemical and Carbonate Looping
Both technologies have significant future potential for the future – and this is
demonstrated by both technical feasibility, systems and economic analysis
•Both technologies are moving to scale (1 – 2 MWth)
•Both carbonate looping and chemical looping are could be built soon, and would have
significantly higher efficiencies than standard post-combustion CO2 capture.
•Further research is necessary to continue improvements in attrition rates, reactivities,
oxygen capacity and to investigate sulphur resistance, NOx production, etc.

35. Ionic liquids as solvents
• What is an Ionic liquid?
• Physical Properties
• Chemical Properties
• Industrial Applications
• Current Research
• Challenges and Opportunities

36. Ionic liquids
• When you heat a salt it will melt (e.g., NaCl,
801°C)
• The melt is composed of mobile ions (ionic
liquid)


37. Many ion choices
• Ionic liquids are salts that are liquid at or near
room temperature
Cations
1-Butyl-3-methylimidazolium Tributylmethylphosponium N,N-Butylmethylpyrrolidinium
[C4C1im] [P4441] [C4C1py]
Anions
Triflate Dicyanamide Methylsulfate Dimethylphosphate Acetate

38. Properties of Ionic Liquids
• Involatility • Synthetic
• High thermal stability flexibility
• High polarity • Easily sourced
• High density • Very high
• High conductivity viscosity
• Large liquid range
• Difficult recovery
• Chemically inert
• Expensive?
• Variable hydrophilicity
• Toxic?

39. efficiency penalty reduction = cost reduction
Eg, post-combustion using amine- solvent imposes an efficiency penalty of 10–12 points
45 - 12 = 33 %, equivalent to 25 % reduction in power output for amine PC capture
amine-solvents ~ 25 % > solid sorbents ~ 17 % > chemical looping ~ 8 %

40. Developed by Nasa and adapted by the
UK Advanced Power Generation
Technology Forum
Technology readiness levels (TRL)
TRLs Status
Applied and strategic research
1 Basic principles observed and reported
2 Technology concept and/or application formulated
3 Analytical and experimental critical function and/or characteristic proof
of concept
4 Technology / part of technology validation in a laboratory environment
Technology validation
5 Technology / part of technology validation in a working environment
6 Technology model or prototype demonstration in a working
environment
System validation
7 Full-scale technology demonstration in working environment
8 Technology completed and ready for deployment through test and
demonstration
9 Technology deployed

41. Technology readiness levels (TRL)… author’s opinion
based on literature survey and publicly available data
Technology TRLs
Post combustion capture with MEA 6
IGCC with physical solvents (e.g. Rectisol process) 6
Oxy-combustion 5
Post-combustion carbonate looping 4–5
Chemical looping combustion 4
Sorbent enhanced reforming 3–4
Post-combustion with algae 3–4
Post-combustion capture with “second generation” sorbents, e.g.: 2–3
supported amines, ionic liquids
Membranes for CO2 capture 2–3
ZECA 1–2

42. Barriers to Uptake?

43. Public acceptance
is the major barrier
for the deployment
CCS
Cartoon from
Nature News
Feature, Vol. 454,
August 2008

44. Efficiency losses
Technology Current state-of-the-art Target efficiency /efficiency
efficiency / efficiency loss loss for 2020
Steam Cycle Efficiency (LCV) ~ 45 % ~ 50 – 55 %
CCS-post combustion ~12 % points ~8 % points
CCS-oxy fuel ~10 % points ~8 % points
CCS – pre combustion ~7 - 9 % point ~5 -6 % point
CCS gas – post com ~ 8 % points ~7 % points
CCS gas - oxyfuel ~11 % points ~8 % points
Now Currently would produce around 25% less electricity for
the same amount of coal burned
20 years 14 – 16 % less electricity than equivalent without CCS
40 years Penalty eliminated (intrinsic separation processes)

45. http://www.bellona.org/ccs/ccs/
Demonstration

46. CO2 sources
http://www.bellona.org/ccs/ccs/
Demonstration

47. CCS projects: possible, speculative,
operational
Demonstration http://www.bellona.org/ccs/ccs/

48. CCS projects: operational
http://www.bellona.org/ccs/ccs/
Demonstration

49. CCS in UK
Project Technology Funding Timing
Awarded No new
Longannet 300 MWe FEED Planned for coal
(Scottish Power) Post-combustion contracts, 2014 without
capture, transport CCS CCS
and storage competition
Awarded 4 full-
300-400 MWe FEED Investment scale, full
Kingsnorth
Post-combustion contracts, decision to be chain
(E.On)
capture, transport CCS reviewed in demos
and storage competition 2016

50. CCS in the UK (more hopeful) – second competition
Project Technology Funding Timing
Peterhead (SSE
386 MWe
and Shell)
Drax / Alstom 426 MWe Oxyfuel
Killingholme 430 MWe
C.Gen Precombustion
900 MWe 180M (EUR)
Don Valley Planned for
IGCC capture, EC funding
(Stainforth) 2015
transport and storage EEPR
300 MWe Post Mired in
Hunterston (Ayr)
Combustion planning
Tees Valley
(progressive 800 MWe IGCC
energy)

51. IEA Energy Technology Perspectives 2008
CCS is as big as renewables in 2050 – actually very soon.
How do we get comparable support and activity now?
Fossil fuel is important for grid stability and is the only way to absolutely
prevent future emissions from fossil fuels (lock them underground as CO2!).
Makes power cheaper by increasing flexibility of generation.

52. Global deployment of CCS , IEA CCS roadmap
100 by
2020
&
3400 by
2050
A lot of
work to
do!
IEA, technology
Roadmap, CCS,
2010

53. E.ON
Robin Irons
Doosan-Babcock
Gnanam Sekkappan
Imperial
Mathieu Lucquiaud,
Hannah Chalmers
Jon Gibbins
IEA GHG
John Davison

54. CO2 capture-ready plants
• The aim of building new power plants that are capture ready is
to reduce the risk of stranded assets and ‘carbon lock-in’
• Developers of capture ready plants should take responsibility
for ensuring that all known factors in their control that would prevent
installation and operation of CO2 capture have been identified and
eliminated
• Key issues include: space for capture equipment, access to
geological storage
• Guidance on space requirements: DECC (Florin and Fennell)
IEA GHG Report 2007/4, May 2007.
http://www.iea.org/textbase/papers/2007/CO2_capture_ready_plants.pdf

55. Bio- energy with CCS (BECCS)
Potential to achieve net removal of CO2 from the atmosphere, or –ve emissions
E.g. biomass burned
in power plant (other
examples in the pulp
CO2 and paper industry,
removed CO2 captured and ethanol plants, CHP
from the stored in plants which emit of
atmosphere geological the order of 100 000
in trees and formation tonnes pa )
crops
Is scaleable.
Costings are done /
being done.
biomass-fired in
a power station

56. Conclusions
CCS is a new technology, but one which is currently being
demonstrated at increasingly large scale
Storage is safe
Plants in the UK must now be built capture-ready
UK Government + Climate change committee are supportive of the
technolgy
Large number of different technologies proposed (and I’ve just
presented the major ones). No clear winners yet.
Efficiency Penalties being reduced.
Only technology for certain applications (for example, cement).

57. CO2 capture From the Air
• It is possible to capture CO2 direct from the air
• It is possible for me to generate electricity with a hand crank
• Is it a good idea?
• Is it scalable?
• Should we ask people other than the purveyors of the technology to do
independent analysis?
• How likely is it that a technology which now costs $250,000 per unit will cost
$25,000 with economies of scale?
• Heath and Safety, efficiency, LCA?
• Is it easier to take water from a river or to condense it out from the air?
• Claims of efficiency often rely on minimal stripping of air – 1 ppm removed...

58. CO2 Re-utilisation
USA ONLY GLOBAL
Source Annual CO2 Percentage of Total Process Global Annual Typical source Lifetime of
production (MtCO2) Emissions CO2 Usage of CO2 used storage
Power 2530 84.0%
Refineries 154 5.1% Urea 65-146Mt^ Industrial 6 Months
Iron & Steel 82 2.7% Methanol 6-8Mt Industrial 6 Months
Gas 77 2.6% Inorganic Carbonates 3-45Mt # ? Decades
Processing
Organic Carbonates 0.2Mt ? Decades
Cement 62 2.1%
Ethylene 61 2.0% Polyurethanes 10Mt ? Decades
Ethanol 31 1.0% Technological 10Mt ? Days to Years
Ammonia 7.8 0.3% Food and drink 8Mt ? Days to Years
Hydrogen 6.8 0.2%
TOTAL 102 – 227Mt
Ethylene 1.2 0.0%
Notes:
Oxide
^, # The demand for CO2 in Urea and Inorganic Carbonate production is
TOTAL 3013 100%
particularly uncertain. Various sources have quoted figures with orders of
Global ~ 10 x USA emissions magnitude differences.
Sources outweigh sinks by several orders of magnitude (more than a factor of 100).
The storage of CO2 is frequently short term.
The huge volume of CO2 produced means that any by-product of CO2 at the scale
required to make a difference in climate terms will immediately saturate the market.
The use of CO2 as a novel feedstock is a good idea if it is justified by the economics –
but will not have significant climate benefit, particularly if the storage is short term.

59. CO2 + 3 H2 = CH3OH + H2O
• Production of liquid fuels from “excess” or “free” renewable energy
• Is there such a thing?
• There is always an opportunity cost – always something else which can be done.
• Is this an efficient way to store the electricity?
Methanol Production and Use Electric Vehicle
Efficiency Efficiency
H2 from water 50% Pumped hydro 70%
H2 + CO2 80% Battery charging1 90%
Use of fuel in ICE 30% Electric Vehicle 90%
Overall 12% Overall 57%
Efficiency
Battery1 90%
Electric Vehicle 90%
Overall 81%
What is the capacity factor for equipment relying on “free” renewable energy? Won’t the
power systems engineers be trying to minimise this?
1Stevens, J.W. And Corey, G.P. A study of lead-acid battery efficiency near top-of-
charge and the impact on PV systems design. Photovoltaic specialists conference,
1996. 13 – 17 May 1996, Washington DC, USA.

60. Mineralisation
• Securely locks away CO2 by reaction with rocks such as serpentine to
produce carbonate rocks
• 3 – 6 times more rock required to be mined than the coal from which it is
capturing the CO2 (basic mass balance)
• Needs to be ground to <100 microns before reaction – electricity use
very significant1
• Reaction slow – approximate sizing for 500MWe equivalent = 4000
tonnes of stone reacting at any moment, with 16,000 tonnes of acid, for a
perfect reactor.
• 100 tonne railway carriage of acid / stone sludge every 8 minutes.
• Scale-up? Contact with CO2? Disposal? LCA (mining CO2 emissions?).
• What else could we do with the resources deployed for this mining?
• Not a viable technology for power stations but does have niche
applications in waste / residue treatment.
1Strubing, MSc, Imperial College, 2007.

61. Conclusions
• There are more efficient CO2 capture technologies than those
currently planned for deployment.
• Some of these may be easier to scale than solvent scrubbing
towers.
• Future processes must at least demonstrate order-of-magnitude
feasibility before funding
• Once kinetics are available, rough flowsheeting and LCA is critical,
together with consideration of Capex and utilisation factors.
• Some processes can be discarded at this stage.
• Chemical Engineering is not about making interesting but
economically unviable processes.
• There is always an opportunity cost, and this should be considered.

62. Acknowledgements
All those who who have been part of the Fennell group at Imperial:
Dr Nick Florin, Dr. Nigel Paterson, Dr. Belen Gonzalez, John Blamey, Dr Mohamad
al-jeboori, Dr Fatima Nyako, Dr. Yatika Somrang, Michaela Nguyen, Charlie Dean,
Kelvin Okpoko, Zhang Zili, Zhou Xin, Tong Danlu, Fola Labiyi
All our collaborators elsewhere:
Prof. Ben Anthony, Dr. Yinghai Wu, Dr. Vasilije Manovic, Dr. Dennis
Lu and Robert Simmons of CanmetENERGY
Prof. Carlos Abanades of INCAR-CSIC
Drs Dennis and Scott at Cambridge
Thanks to John Dennis at Cambridge for his slides on Chemical looping
Jason Hallet, Imperial College dept of Chemistry, for slides on ionic
liquids
Andres Sanchez at Endesa for slides regarding Caoling

63. Acknowledgements
•The research leading to these results has
received funding from:
•Engineering and Physical Sciences Research
Council (EPSRC), UK
•Grantham Institute for Climate Change, IC
–European Community's Seventh Framework Programme(FP7/2007-2013)
under GA 241302-CaOling Project

64. Basic Information
http://www3.imperial.ac.uk/climatechange/publications
Advanced Information
An overview of CO2 capture technologies
Niall MacDowell, Nick Florin, Antoine Buchard, Jason Hallett, Amparo Galindo, George Jackson, Claire S.
Adjiman, Charlotte K. Williams, Nilay Shah and Paul Fennell *
Energy Environ. Sci., 2010, 3, 1645-1669
DOI: 10.1039/C004106H, Review
Dr Paul Fennell (p.fennell@imperial.ac.uk)
Department of Chemical Engineering and Chemical Technology, ICL

65. For Further Information:
• Blamey, J., Anthony, E. J., Wang, J., Fennell, P. S.; The calcium looping cycle for
large-scale CO2 capture; Prog. Energy Combust. Sci. 2010 36, 260-279
• Blamey, J., Paterson, N. P. M., Dugwell, D. R., Fennell, P. S.; Mechanism of Particle
Breakage during Reactivation of CaO-Based Sorbents for CO2 Capture; Energy &
Fuels 2010, 24, 4605-4616
• Blamey, J., Lu, D. Y., Fennell, P. S., Anthony, E. J.; Reactivation of CaO-Based
Sorbents for CO2 Capture: Mechanism for the Carbonation of Ca(OH)2; Industrial &
Engineering Chemistry Research, 2011, 50, 10329-10334
• Gonzalez, B., Blamey, J., McBride-Wright, M., Carter, N., Dugwell, D., Fennell, P.,
Abanades, C.; Calcium Looping for CO2 Capture: Sorbent Enhancement Through
Doping; Energy Procedia, 2011, 4, 402-409
• Fennell, P. S., Al-Jeboori, M.; CaO-based Sorbent Enhancement through Doping;
UK Priority Patent Application number 1114105.8, filed on August 16, 2011 in the
name of Imperial Innovations Ltd
• Donat, F., Florin, N. H., Anthony, E. J., Fennell, P. S.; The influence of high-
temperature steam on the reactivity of CaO sorbent for CO2 capture; Environmental
Science and Technology (submitted)