APPENDIX 28
Memorandum from the Cambridge Environmental
Initiative (CEI)
VIABILITY OF
CARBON CAPTURE
AND STORAGE
(CCS) AS A
CARBON ABATEMENT
TECHNOLOGY FOR
THE UK: FEASIBILITY
AND COSTS
This paper summarises the key points from a
discussion meeting held at the Department of Earth Sciences, University
of Cambridge, on Thursday 6 October 2005. The meeting was held
in response to the UK Government Science and Technology Select
Committee inquiry into carbon capture and storage.
The following people participated in the discussion,
representing a selection of research groups and departments within
the University of Cambridge:
Professor Herbert Huppert FRS, Director of the
Institute of Geophysics (Discussion chair)
Research interests: modeling of fluid flows, relevant
to some aspects of carbon sequestration.
Professor Mike Bickle, Department of Earth Sciences
Geochemist with expertise in modeling the likely
consequences of storing CO2 over geological time scales.
Dr Silvana Cardosa, Reader in Chemical Engineering
Research interests: seawater/ CO2 chemical
reactions
Dr Chris Hope, Senior Lecturer in Operational
Research, Judge Business School
Expertise in modelling of risk and the costs and
benefits of climate change.
Dr Tamsin Mather, Department of Earth Sciences
Geologist; produced a briefing paper for the Parliamentary
Office for Science and Technology on CCS.
Dr David Reiner, Lecturer in Technology Policy,
Judge Business School
Research interests: public perception of CCS; climate
policy research; works with the UK carbon capture consortium.
Dr Nicky White, Reader in Earth Sciences
Expertise in 3D modelling, important for monitoring
geological processes concerned with CO2 storage in
geological structures.
Professor John Young, Professor of Applied Thermodynamics,
Department of Engineering
Expertise in the thermodynamics of capturing CO2
at source from power stations
1. KEY POINTS
In terms of technological development and scientific
understanding, there are two major areas requiring further work:
— Carbon capture at source: optimising
the separation of CO2 from other flue gases
— Carbon storage: understanding the
long-term behaviour of CO2 stored in geological strata.
Assessing the economic viability of carbon capture
and storage is dependent on several factors:
— future cost reductions in the capture
process;
— access to reservoirs for storage;
— public acceptability of storage sites
and its costs relative to other electricity generation options.
2. SUMMARY OF
DISCUSSION
2.1 Carbon capture at source
Carbon capture at source is currently considered
to be expensive. There are significant economies of scale for
very large scale power plants eg 1,000MW. Carbon capture can either
take place post-combustion or pre-combustion. Currently pre-combustion
capture is most promising in terms of separating the CO2
efficiently and economically from the gas stream.
Although basic turbo machinery is available
now it may take many years to develop the new types of turbines
required for power generation using "clean" fossil fuels.
The UK does not currently manufacture the large turbines required
(>250MW). Developing turbines optimised for power plants in
which pre-combustion separation could occur represents significant
design modification. Ideally this process should begin now, however
development in this field is purely market-driven and companies
will not invest unless there are strong financial incentives to
do so. Even proven design changes that will increase efficiency
are made very reluctantly. Implementing design changes in existing
power plants would require substantial and costly redevelopment
of the current power generation infrastructure. So the costs for
developing new turbines for power generation and capture of carbon
on-site should not be underestimated.
2.2 Carbon storage
Once carbon dioxide has been captured, it needs
to be stored to reduce build up of carbon dioxide in the atmosphere.
The practice of pumping CO2 captured from a fuel production
site into an existing oil or gas reservoir that has been depleted
of its reserves is already established. Once there, it is possible
to monitor the movement of the CO2 within the geological
structure. Note the USA alone has an estimated saline reservoir
storage capacity of 130 Gt (equivalent to 20 years of carbon emissions
at the current rate of burning fossil fuels).
BP, together with Scottish & Southern, ConocoPhillips
and Shell, have recently launched a project in Scotland to separate
CO2 and hydrogen at a power plant at Peterhead (near
Aberdeen) and then use the CO2 for enhanced oil recovery
(EOR) in the Miller Field in the North Sea. The conditions of
storage are not known, so seismic monitoring is being used to
monitor the movement of the gas. Geophysicists at the University
of Cambridge are working on the imagery and the problems associated
with repeat seismic imaging. They are also using data from the
Sleipner oilfield[34]
but the raw data is not accessible from Statoil.
2.3 What are the risks?
A leak from a CO2 storage reservoir
would be likely to occur slowly permitting the recovery and re-storage
of the gas. On a global climate change scale, the loss of CO2
from one field would not cause significant environmental hazard,
and is nowhere near as insidious as nuclear waste hazard as a
potential problem.
The risks with CO2 storage are potential
damage to pipelines taking CO2 to the storage sites
and potential leakages from pipelines poisoning nearby communities.
One area for further research is to investigate the spread of
CO2 plumes in UK conditions and the wind conditions
required to disperse them. This may be no worse than the risks
associated with existing oil and gas pipelines.
2.4 Public understanding
Mitigation of the effects of CO2
emissions via technological intervention needs international and
inter-disciplinary collaboration. While geologists believe CCS
to be viable, it is not just a technical problem, it is also important
to establish public confidence in the method. One way of doing
this is by early and thorough consultation with a diverse range
of stakeholder groups (eg, environmental NGOs, local communities
etc). Care should also be taken that the source of funding for
particular research projects is not seen to undermine the objectivity
of conclusions made.
The problems of storage of nuclear waste have
made the public very suspicious of long- term storage of waste
products associated with power generation. However, the public
are more familiar with CO2 than many other substances
and understand that CO2 is emitted by cars, power plants
and exhaled by people, and is sequestered by trees and plants.
The challenge is in the presentation of the concepts and the inferences
of long term storage are important. Some pressure groups may try
to highlight extreme events involving CO2 such as stories
of explosions and loss of life in Cameroon, Africa resulting from
naturally occurring volcanic CO2 leakage at Lakes Mounoun
and Nyos in the 1980s.[35]
Transparency of information is essential to enable academic analysis
and further research and to avoid a similar scenario to that of
the early years of the nuclear energy age, when raw data was kept
secret provoking public suspicion about the technology.
2.5 A global challenge
In the time taken for the UK to debate its course
of action, China will have built new coal power stations of many
Gigawatts capacity, the effect of which will dominate global CO2
emissions. Every country now lives in a global world: environmental
problems in other countries have immediate and major impact on
the UK and likewise our pollution issues have major impacts elsewhere.
Clean fossil fuel technologies are obviously attractive for the
immediate future. Nuclear power represents another low carbon
power generation route, although issues of waste management, technological
barriers and fears concerning nuclear weapon proliferation may
limit the extent to which it offers a solution for future global
power requirements. Elimination of nuclear power as an energy
generation option will have serious consequences in terms of CO2
emissions.
A key question in tackling CO2 emissions
will be to what extent the West is prepared to encourage China
to build power plants that will not contribute further to the
emission of greenhouse gases into the atmosphere. China and India
have a strong moral case for suggesting that developed countries
must pay for the development of clean fuel technologies. The UK
Government should look at what the costs of these technologies
will be, and then compare that with the benefits of reducing carbon
emissions to the atmosphere. This will allow a sensible economic
decision to be taken.
Within the next two decades, the true effects
of climate change will start to become apparent. Large scale destruction
in major cities by extreme weather conditions in Developed countries
may stimulate action. The cost of carbon is rising at about 3%
per year, and in 30 years the cost of carbon will most likely
be high. The real challenge is to respond now, before it is a
necessity, particularly to allow industry to make the necessary
technical developments.
October 2005
34 see http://www.statoil.com/STATOILCOM/SVG00990.NSF/web/sleipneren?opendocument Back
35
see http://news.bbc.co.uk/1/hi/sci/tech/4285878.stm Back
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