CO2 Capture and Storage – Part of the Solution to the Climate Change Problem?
Dinner-Debate
at the invitation of Vattenfall
Event date(s) :
2005/01/17
Item's Code :
DD20050117
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Entity(ies) metioned in or related to this article :
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Theme(s) describing this article :
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Speaker : Professor Lars Strömberg, Vattenfall AB
Climate change and energy policy are closely entwined. If we are serious about reducing CO2 emissions, we must explore a wide spectrum of engineering, technical and policy solutions to this global challenge.
A carbon-free, coal-fired power plant could be an important part of the solution as soon as the market is ready to accept the higher cost level. Even with very high ambitions to reduce emissions of carbon dioxide we have to recognize continued and even increased use of fossil fuels for a long period of time. This is especially relevant for coal that is of crucial importance to the security of energy supply. The same goes for lignite, which is, in addition, an indigenous fuel in some countries. Therefore, huge efforts are made worldwide to develop technology for CO2 capture and storage.
As an engineer Professor Strömberg maintains that the technology is not a problem and the potential is huge, much larger than any of the existing truly regenerative technologies - and less expensive. The problem lies in the “soft issues” such as legal aspects, building acceptance, development of an infrastructure and how the emission trading system will develop. All these issues will be addressed by Professor Strömberg at the dinner debate.
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Fossil fuels – an essential part of our society
| Fossil |
64,40%
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| Hydro |
17,10%
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| Nuclear |
16,90%
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| Others |
1,60%
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Report: Prospects for CO2 Capture and Storage (IEA 2004)
“Both the WEO (IEA-Word Energy Outlook 2004) Reference Scenario and the IPCC scenarios show: unless much stronger action is taken, CO2 emissions will continue growing, with potentially serious implications for global warming.”
“A number of options exist that can reduce the CO2 emissions from the energy system. These include improved energy efficiency and switch to renewable and nuclear energy. However, policies based on these options will, at best, only partly solve the problem. Carbon dioxide capture & storage (CCS) technologies constitute another promising option that can drastically reduce these emissions. To accomplish this, governments need to take action now to ensure that CCS technologies are developed and deployed on large scale over next few decades.”
“The result show that, …..in all cases CCS can play an important role, and can allow a gradual transition to renewables in the long term. CCS and renewables should therefore not be considered as competing but as complementary options”
The EU scheme for GHG emission trading
“The Directive establishes a scheme for greenhouse gas emission allowance trading within the European Community to promote reductions of greenhouse gas emissions in an economically efficient manner”. (See also : Amendment of the Directive establishing a scheme for greenhouse gas emission allowance trading within the Community, in respect of the Kyoto Protocol's project mechanisms)
Adopted by European Parliament 2 July 2003
January 2005: Effective
First period: 2005-2007
Second period: 2008-2012
Analyses show that…
by 2010 …
- Costs for emission allowances might be around 10 EUR/ton of CO2
but in 2015…
- If the trading system prevails
- When new technology for fossil fuels with near zero emissions, can play a significant role
- The cost for emission allowances will increase to 20 EUR/ton of CO2 or higher depending on reduction demand.
This is the target to be met by new ”zero emission” technology.
Power Plant Lippendorf
CO2 Emissions from different Power Plant
The CO2-free Power Plant principle
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The principle of capture and storage of the CO2 under ground.
The CO2 can be captured either from the fuel gases, or is the carbon captured from the fuel before the combustion process.
The CO2 is cleaned and compressed. Then it is pumped as a liquid down into a porous rock formation for permanent storage. |
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Storage of CO2 in a Saline Aquifer under the North Sea
Storage Capacity, saline aquifers
Source: Franz May, Peter Gerling, Paul Krull; Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover
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Specific problems:
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CO2 free power plant - Storage Demo
The map shows the storage sites evaluated within the federal states Brandenburg and Mecklenburg- Vorpommern. The location of the Structure Schweinrich and Schwarze Pumpe power plant are marked.
CO2 pipelines in operation in the USA
Transportation with water carriers
Post-combustion capture
This technology is already commercially available in large scale (500 MW). It is at present the most expensive.
Pre-combustion capture
This technology needs development. Might be competitive. The gasifier exists in demo plants. The turbine is in the lab stage. Produces Hydrogen as an intermediary product.
O2/CO2 combustion is the preferred option at present
At present the most competitive and preferred technology for coal. It needs development, pilot and demo plants to get design data.
The reference power plant Lippendorf
Investment cost for a third lignite fired power unit with O2/CO2 combustion similar to the two existing at Lippendorff
| Power Plant |
89%
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| Air Separation |
9%
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| Compression |
2%
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Energy flow diagram for the existing lignite fired Power Unit
Energy flow diagram for a new similar unit with O2/CO2 combustion
CO2 Capture : Evaluation of options with CO2 trading price of 20 euros per ton
Assume that a new alternative replaces 1 MWh with old coalfiring. This means it reduces emissions with about 1 ton of CO2. 1 MWh of electricity costs about 30 euros to produce with the old plant (the marginal plant).
- Windpower costs in average 92 euros/MWh during 2004 in Germany
- Biofuelled power costs from about 65 euros/kWh (fuel only about 35 euros/Mwh) for cogeneration and 85 for electricity only
- The green certificates costs about 195 euros/MWh at present
The avoidance costs for these alternatives will then be:
- Wind: 62 euros/ton CO2
- Biopower: 35 to 55 euros/ton of CO2
Thus Carbon Capture and Storage can, if development is successful, reduce cost for avoidance significantly!
CO2 free Power Plant : 15 years of research and development
The technical target was expressed as:
- Total cost below 20 €/ton stored CO2
- Capture efficiency above 95 %
The project contains 5 stages
- We are in the middle of the Concept development phase, which contains pilot plant(s)
- Construction of a full scale demo plant is scheduled to start 2010
CO2 Free Power Plant and other initiatives
CO2 Free Power Plant –Work Scheme
Kraftwerk Boxberg
CO2 Free Power Plant Demo : Cost Distribution
Post-combustion capture – absorption process
This technology is already commercially available in large scale (500 MW). It is at present the most expensive.
Pre-combustion - decarbonisation capture
This technology needs development. Might be competitive. The gasifier exists in demo plants. The turbine is in the lab stage. Produces Hydrogen as an intermediary product.
O2/CO2 recycle (oxyfuel) combustion capture
At present the most competitive and preferred technology for coal. It needs development, pilot and demo plants to get design data.
Share of workload and results Vattenfall/RWE (Oxyfuel)
Market readiness Oxyfuel Process:
The Oxyfuel Process needs a pilot plant to give design criteria for the combustion process and show if it is technically and economically feasible.
Share of workload and results Vattenfall/RWE (IGCC)
Market readiness IGCC Process:
The IGCC process is in some aspects further developed, due to four full size plants in Purtollano (ESP) and Buggenum (NL) and two in the USA.
Comparison Oxyfuel - IGCC
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IGCC Process
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Oxyfuel Process
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The process design of the O2/CO2 power plant
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Fuel gas treatment and liquifaction of the CO2. |
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The power plant process. Original gross output 933 MW |
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Air separation
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CO2 free power plant - Storage Demo
Schweinrich Site - Geological Characterisation
Cross section of the Schweinrich Structure showing an anticlinal closure positioned between two salt diapirs.
The yellow arrows indicate the reservoir and storage position. (Clic on the image to enlarge it)
The selected storage site beneath the small village Schweinrich is a passive anticlinal structure with reservoir formations within the Lower Jurassic (Lias) and the Uppermost Triassic (Rhät- Keuper.
The reservoir (saline aquifers) is about 150 metres tick and consists of several layers of fine-grained, highly porous sandstones overlain by thick Jurassic clayey formations.
The storage site covers about 100 km2 and provides a calculated total storage capacity of more than 1000 Mtons CO2. The CO2 could be transported from the Schwarze Pumpe power plant to the storage site Schweinrich via pipelines (about 200 km distance).
Storage cost estimates : Storage in aquifer traps (GESTCO Figures)
Costs depend strongly on the depth of subsurface layers used for storage.
The strongest subsurface uncertainty in storage costs lies in the time it takes to fill the trap.
The second important uncertainty parameter is the exploration success ratio of finding a suitable trap.
Dutch case: CO2 source of 5.7 Mton/year stored in one megatrap or a conglomerate of traps. Total sequestration cost: 17-20 Euro/ton CO2 av.
Transport costs for CO2 Cost and capacity ranges
The ENCAP Project
• In total a 5 year project.
• Total budget amounts to about 25 million €, whereof a majority from industry
• Develop, optimize and verify ”pre-combustion” and CO2/O2 capture technologies
• Development target 20 EUR/ton CO2 avoided, with capture yields in excess of 90%
• Focus will be on technology for new plants
The EU Sponsored large projects
• ENCAP
– Pre-combustion, Oxy Fuel capture and Chemical looping. Leads to a base for a demo
• Castor
– Post combustion capture. Parallel to ENCAP.
• CO2SINK
– Storage project. Existing gas storage outside Berlin. Problem with CO2 supply.
• CO2Store
– Storage possibilities in Europe. General and case studies.
• CO2Move
– CO2 properties, environmental implications. Transport systems.
• Dunamis (Hypogen)
– Lighthouse project. Preparation for a large demo for hydrogen production.
• CO2NET
– Network around the CO2 capture and storage issue. 54 members.
See the Item's Reference(s) for more information.
