1. Mitglied der Helmholtz-Gemeinschaft Routen der CO 2 -Abscheidung in Kraftwerken E. Riensche, J. Nazarko, S. Schiebahn, M. Weber, L. Zhao, D. Stolten Forschungszentrum Jülich GmbH, D-52425 Jülich Institut für Energie- und Klimaforschung – IEK-3: Brennstoffzellen Jahreshaupttagung der DPG - Arbeitskreis Energie (AKE) Dresden, 13.-16. März 2011

2. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 2 Introduction Three phases of power production from coal occur: 20 th century: Continually increasing efficiency up to ……………..….… ~45 % Ending with: Flue gas cleaning (DeNOx, Dedust, DeSOx) ……….....… 1-2 %-points loss 21 th century: Necessity for CCS (Carbon Capture and Storage) … ~8-14 %-points loss Challenge of CCS: Collecting CO 2 as pure as possible High efficiency of power production Current efficiency penalties of 12-14 %-points CO 2 separation degrees ~90% and CO 2 purities between ~90 and 99 mol% R&D: Gas separation Integrated CCS systems

3. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 3 Potential power plant modifications Further flue gas cleaning CO shift Recirculation Gas/gas separation Potential subsequent CO 2 cleaning CO 2 com- pression 1  100 bar liquefaction CO 2 /N 2 O 2 /N 2, CO 2 /H 2 O CO 2 /H 2 123456 CO 2 separationCO 2 transport and storage Further compression Exceptions: e.g. post comb. chilled ammonia 15-20  100 bar Pipeline e.g. 500 km pressure drop 200  100 bar Potential further compression Up to 1000 bar Injection at significant depth e.g. aquifers in Germany 1 – 10 km Power plant CCS Process Steps Up to 6 processes contribute to CCS energy demand  Accumulated losses to be minimized

4. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 4 MJ/kg fuel 32.825.050.0 MJ/kg CO2 kWh th /t CO2 8.94 2480 10.5 2910 18.2 5050 Emission: Nm³ CO2 /kWh th 0.2050.1750.101 LHV / MJ/kg CO2 0 20 Typical Coal LHV / kWh th /Nm³ CO2 0 5 10 100% 10 117% 203% CH 4 C Data Base of Energy Content for Fossil Fuels Typical coal: LHV = 2910 kWh th /t CO2 produced  Efficiency loss = 1 %-point for CCS energy demand of 29 kWh e /t CO2 (100% separated) Source: Reference power plant NRW, VGB 2004

5. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 5 Separation Routes, Tasks and Methods

6. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 6 Separation principles Materials Sep. gas CO 2 O2O2 or H 2 O2O2 H2H2 MIEC:Mixed Ionic-Electronic Conductor MPEC:Mixed Protonic-Electronic Conductor Separation methods Chemical Physical Molecular transport Ionic / atomic transport Condensation & Rectification Me MeO AO ACO 3 Absorption with liquids Reaction with solids (Chemical Looping) Cryogenic air separation Membranes Amines Amino salts Ammonia “Rectisol” “Selexol” “Purisol” Ni, Cu, Fe CaO, MgO, FeO Polymer Microporous MIEC for O 2 sep. MPEC for H 2 sep. Metallic Prevalent Gas Separation Methods

7. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 7 Solvent Regene- ration Solvent make-up Energy Spent solvent CO 2 Gas with CO 2 Solvent + CO 2 Solvent Purified Gas Absorption with Liquids  Chemical absorption for low CO 2 partial pressures, e.g. flue gases  Physical absorption for high CO 2 partial pressures, e.g. coal gas (IGCC, pressurized) p CO2 ~5-10 bar IGCC Flue gas Henry´s law CO 2 Cap- ture

8. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 8 Oxidation unit (Air reactor) Reduction unit (Fuel reactor) Fuel CO 2 + H 2 O Air Ni NiO Oxyfuel via Chemical Looping Combustion Absorption (Carbo- nizing) T = 650 °C Regene- ration (Calcining) T = 900 °C CO 2 for compression Coal gas or flue gas with CO 2 CaO CaCO 3 Carbonate Looping CO 2 -free flue gas Make-up CaCO 3 Fuel Oxygen Ash CaO CaCO 3 Reaction with Solids CLC: applicable for coal gas & natural gas CLC: direct oxygen transport via a metal carrier  CLC promises energy saving oxygen delivery for oxyfuel

9. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 9 CO 2 p CO2 ~10 bar p CO2 ~1 bar p ~100 bar p ~1 bar Natural gas Polymer Membranes: CO 2 Separation from Natural Gas Transport: solution diffusion mechanism Driving force: partial pressure difference Compressors: not required in natural gas fields Integration in coal power plants: - Limitation in operating temperature - Compression energy to be considered Example for a natural gas field

10. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 10 150 - 400 °C Metallic 800 - 1000 °C500 - 800 °CUp to 600 °C Dense 150 - 400 °C Inorganic Membranes Ceramic Microporous Dense MIEC: Mixed Ionic-Electronic Conductors O 2- /e - MPEC: Mixed Protonic-Electronic Conductors H + /e - Diffusion of H- atoms Amorphous: e.g. Sol-gel membranes Crystalline: e.g. Zeolites CO 2 /N 2 – Post H 2 /CO 2 – Pre(H 2 ) O 2 /N 2 – Oxy H 2 /CO 2 – Pre(H 2 ) Inorganic Membranes

11. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 11 Basic conceptGas separation method Route Gas sepa- ration task Cond.Absorption / ReactionMembrane separation Cryog. air sepa- ration Absorption w. liquidsReaction with solids PolymerPorous Mixed cond. Metallic ChemicalPhysicalAdsorptionReaction Post CO 2 SPP IGCC* SPP IGCC* SPP IGCC* SPP IGCC* Oxy O2O2 SPP IGCC SPP IGCC SPP IGCC SPP IGCC Pre CO 2 IGCC + Shift H2H2 IGCC + Shift** * Flue gas recycle for higher CO 2 concentration ** Flue gas recycle for membrane sweep with a large O 2 -poor N 2 gas stream Résumé: CCS Power Plant Classes Today: two power plant technologies: Steam Power Plant (SPP) and IGCC Identified: 32 CCS power plant classes

12. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 12 Post-combustion (basic) Post-combustion with flue gas recycling (advanced) Oxyfuel (with flue gas recycling) n/a GT ST CO 2 H 2 O ASU O2O2 GT ST CO 2 GT ST Coal gasCO 2 Air CO 2 ~6% SG Air Coal gas Air Coal gas CO 2 ~13-15%CO 2 ~90% Steam power plant IGCC ST CO 2 H 2 O ASU O2O2 ST Coal CO 2 N 2, (H 2 O) Air CO 2 ~12-14% Coal Air CO 2 ~90% λ~1 λ~2.5 Increase of CO 2 Concentrations through Flue Gas Recycling : air ratio, ASU: air separation unit, GT: gas turbine, SG: steam generator, ST: steam turbine N 2 ~70% O 2 ~10% N 2 ~5% O 2 ~0%

13. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 13 Flue gas Absorber CO 2 +H 2 OCO 2 -free flue gas Heat supply Desorber Heat exchanger 55°C 40°C60°C 100°C 90°C Post-combustion: Amine Scrubbing Absorption heat is released at low temperature Desorption requires heat at higher temperature Heat supplied by steam condensation at the desorber

14. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 14  CO 2 released at 10 bar takes 2 %-points (e.g. Post-combustion/Chilled ammonia)  CO 2 released at 30 bar takes 1 %-point (e.g. Pre-combustion/H 2 membrane) For compression to 120 bar CO 2 captured at 1 bar takes from efficiency 4 %-points (100% CO 2 separation, 5 mol% N 2 ) Final Compression of Captured CO 2 to 120 bar 0 20 40 60 80 100 120 020406080100120 CO 2 pressure after capture / bar 0 1 2 3 4 Plant efficiency loss / %-points Compression energy / kWh/t CO2 Source: after Göttlicher 2004

15. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 15 CO 2 Phase Diagram for Pure CO 2 and CO 2 -N 2 Mixtures Pure CO 2 : Two-phase behaviour only at the saturation line Impure CO 2 : Two-phase regions occur - exceeding 100 bar  Work hypothesis for pipeline transport: 5 mol% N 2 tolerable Source: Goos, Riedel, Zhao, Blum, GHGT-10, Amsterdam 2010 Pipeline

16. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 16 Conclusions CCS concepts encompass a broad variety of solutions Post-combustion, Oxyfuel, Pre-combustion Gas separation: Absorption, Adsorption, Reaction with solids, Rectification, Membranes. All concepts show potentials for further improvement Materials´ and componenent development Integration of components and “CCS waste heat” (from capture and compression). The minimum efficiency penalty for CCS is estimated to be 4 %-points for CO 2 capture from flue gas (90% separation) and Even potentially lower, if separation of pure gases is avoided, e.g. by - Membrane sweep (permeation - dilution) and - Chemical looping (e.g. reaction of O 2 with a metal carrier – directly in air). Successful development of CCS concepts will require in-depth dialogue between process engineers and material scientists.

17. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 17 Efficient Carbon Capture for Coal Power Plants June 20-22-2011, Frankfurt am Main www.icepe2011.de Thank You for Your Attention!

18. CO 2 -Abscheidung, Vortrag D. Stolten, Dresden 16.03.2011Folie 18 Thank You for Your Attention! 2nd International Conference on Process Engineering Efficient Carbon Capture for Coal Power Plants June 20-22, 2011 Frankfurt am Main/ Germany Registration: www.icepe2011.de