Overview of Techniques and Approaches to CO 2 Capture

Overview of Techniques and Approaches to CO 2 Capture by Alain Bill ALSTOM Power Presentation to UNECE Carbon Sequestration Workshop Geneva, 19 November 2002 www.ieagreen.org.uk

CO 2 Capture Overview IEA Greenhouse Gas R&D Programme The need for emission reductions Power generation and capture of CO 2 Other sources of CO 2 Overview of costs Conclusions

IEA Greenhouse Gas R&D Programme Australia Belgium Canada CEC Denmark Finland France Japan Korea Netherlands New Zealand Norway Sweden Switzerland UK USA Venezuela Sponsors: ALSTOM Power Technology, BP, ChevronTexaco, EniTecnologie, EPRI, ExxonMobil, RWE, Shell, TotalFinaElf

IEA Greenhouse Gas Programme Objectives: Evaluate technologies for the abatement of greenhouse gas emissions Communicate results Develop targets for research Facilitate R&D and demonstration projects

Tackling climate change Background Rising levels of greenhouse gases in the atmosphere are changing the climate To avoid dangerous changes, will need to stabilise greenhouse gas concentrations IPCC 1 has indicated that deep reductions (>60%) will be required in global emissions To stabilise atmospheric concentrations of greenhouse gases, will eventually need zero net emissions 1 Intergovernmental Panel on Climate Change

Technology Options Stabilise atmospheric CO 2 levels by Reducing energy use Switching to different fuels Natural gas in place of coal Renewable energy - e.g. wind, biomass Nuclear power Sequestering CO 2 Enhance natural sinks for CO 2 Capture and storage of CO 2

Capture and storage of CO 2 Overview Capture and storage could deliver deep reductions in CO 2 emissions Uses technology proven in other applications Complementary to other mitigation options There is no magic bullet to solve the problem of climate change

Capture and storage of CO 2 Power generation post-combustion capture N 2, H 2 O to atmosphere Flue gases CO 2 Separation CO 2 Compression Storage Fossil fuel combustion Power Generation

Post-combustion capture Current status Power generation: PF and NGCC in general use CO 2 separation: Amine-scrubbing e.g. mono-ethanolamine (MEA) Experience >60 years Mainly in reducing atmospheres In use today, capturing CO 2 for soft drinks

Emission Reduction CO 2 Emissions (kg/kwh) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Natural Gas Coal Without capture With capture

Power Generation Efficiency %, LHV 60 50 40 Without capture With capture 30 20 10 0 Gas combined cycle Pulverised coal

Cost of Electricity Generation US c/kwh 8 7 6 5 4 3 2 1 0 Gas $2/GJ Coal $1.5/GJ Without capture With capture 10% discount rate

Cost of Electricity Generation US c/kwh 8 7 6 5 4 3 2 1 0 Gas $5/GJ Coal $1/GJ Without capture With capture 10% discount rate

Post combustion capture Amine scrubbing Could make deep reductions in emissions Increases generating costs by 50-90% Reduces energy efficiency by 8-13 % points Solvent degrades, especially in oxidising environment To improve, try changing: Method of capturing CO 2 Power generation cycle

CO 2 Capture Separation techniques Solvent Absorption Chemical solvent e.g. MEA Physical solvent e.g. Selexol TM

CO 2 Capture Separation techniques Solvent Absorption Chemical solvent e.g. MEA Physical solvent e.g. Selexol TM Adsorption on a solid Pressure Swing Adsorption (PSA) Temperature Swing Adsorption (TSA)

Power Generation Cycles Options Using established technology: Pre-combustion decarbonisation New concepts: Alter combustion conditions

Power Generation with Capture Pre-combustion decarbonisation: coal IGCC with shift Coal Gasifier Shift Reactor CO 2 Separation CO 2 Storage O 2 N 2 H 2 Air Separation Unit GT CC

Power Generation with Capture Pre-combustion decarbonisation: gas Natural gas Combination of known technologies Partial Oxidation* Shift Reactor CO 2 Separation CO 2 Storage H 2 /N 2 * or Autothermal reformer or Steam reformer GT CC

Pre-combustion decarbonisation Current status Based on near-commercial technology Additional component = shift reactor Gas turbine must be capable of using H 2 -rich fuel NO x emission control CO 2 separation Physical solvent well established in this type of duty

Power Generation with Capture Alter combustion conditions Recycle CO 2 or H 2 O or Partial recycle of CO 2 CO 2 or H 2 O Fossil fuel combustion Power Generation Separation CO 2 Storage O 2 Air Separation Unit

Altered combustion conditions Current status Research currently in Canada, Japan, etc Focussed mainly on boilers Partial recycle - doubles CO 2 concentration CO 2 separation - solvent absorption Full recycle Produces concentrated CO 2 stream CO 2 separation - essentially removal of water Requires ASU Substantial development work required

Economics of capture Gas-fired plant Post combustion Partial recycle Pre combustion Efficiency (lhv) 47% 48% 48% Cost of electricity (c/kwh)* 3.2 3.1 3.4 Cost of avoidance ($/tco 2 ) 32 29 39 *Natural gas at 2$/GJ, 10% discount rate

Additional generating costs c/kwh 3 2 1 Transport/ storage Capture plant Power plant Fuel 0 Gas Coal Post combustion Coal Pre-combustion Gas @ $2/GJ Coal @ $1.5/GJ

Other Potential Applications Capture and storage of CO 2 Power generation The conventional application Major energy using industry e.g. Oil refining Manufacture of decarbonised fuel for transport e.g. H 2 from natural gas

Conclusions CO 2 capture and storage Can be delivered using known technology Would make deep reductions in emissions Cost comparable with other options

Conclusions CO 2 capture and storage Can be delivered using known technology Would make deep reductions in emissions Cost comparable with other options Opportunities for action Reduce cost to encourage early application Demonstrate full-scale application Ensure minimal environmental impact Verify amount of CO 2 stored