Pre combustion CO 2 capture

Transcription

1 Pre combustion CO 2 capture Daniel Jansen Presented at the 2 nd International Workshop CCS and CCU, Germany (Conference 9-10 November 2011) ECN-M NOVEMBER 2011

2 Pre combustion CO 2 capture Daniel Jansen Energy research Centre of the Netherlands 2 nd international workshop: CCS and CCU in Germany, The Netherlands, Norway, Poland and Scotland - Challenges and Changes Düsseldorf, Germany, 2011, 9th/10th November

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4 Pre-Combustion CO 2 Capture Removes carbon from the fuel before combustion -Carbon is captured in the form of CO 2 -Hydrogen is the resulting fuel Well known process used for H 2 generation for > 50 years Currently used to produce high-purity H 2 for chemical and refining uses This presentation focus on coal 3

5 Pre-Combustion CO 2 Capture Today Technologies for hydrocarbon conversion Variety of gas treating technologies available High energy penalty Developments to reduce energy penalty Advanced solvents Advanced shift Reaction/separation integration: SEWGS

6 Pre combustion capture as of today In Combined cycles; large scale deployment NGCC - Reforming and gas separation technologies commercial available In IGCC; no large scale deployment of IGCC - Gas separation technologies commercial available - More experience in ammonia, chemicals production, esp. in China Dry-fed (N 2 ) or Slurry-fed (H 2 O) Coal Gasification Steam Sour Shift Watergas-shift Clean Shift Coal Gasifier Gas Cooler or Wet Quench Particulate Removal H 2 S Removal CO 2 separation CC O 2 Air ASU CO 2 compression CO

7 Pre-Combustion Coal fuelled systems Solid hydrocarbon conversion - Convert hydrocarbon into H 2, CO and CO 2. - This is done by gasification (GE, Shell, E-gas) Source Oil & gas science and Technology, Vol 60, 2005 No

8 Pre combustion Gasification with carbon removal Gas treatment 35 C 35 C Oxygen C 100 C Pulverised Coal H 2 30 C Gas treatment Sulphur absorption steam Clean gas shift CO 2 absorption Gasifier

9 Existing (sour) gas treating processes Monoethanolamine MEA O O O Diethanolamine DEA O Diisopropanolamine ADIP O Methyldiethanolamine MDEA O O O Potassium carbonate Hotpot O O O Methanol+MDEA/DEA Amisol O XXX+MDEA Flexsorb O Sulfolane+MDEA/DIPA Sulfinol O DME of PE glycol Selexol O Methanol Rectisol O O N-Methylpyrrolidone Purisol O PE glycol + dialkyl ether Sepasolv O 330 MW e NGCC Power Plant. Based on January 2006 prices. Propylene carbonate Fluor solvent O Tetrahydrothiophenedioxide Sulfolane O Tributyl phosphate Estasolvan O C h e m i c a l M i x e d P h y s i c a l 8

10 Monoethanolamine MEA O O O Diethanolamine DEA O Diisopropanolamine ADIP O Methyldiethanolamine MDEA O O O Potassium carbonate Hotpot O O O Methanol+MDEA/DEA Amisol O XXX+MDEA Flexsorb O Sulfolane+MDEA/DIPA Sulfinol O DME of PE glycol Selexol O Methanol Rectisol O O N-Methylpyrrolidone Purisol O PE glycol + dialkyl ether Sepasolv O 330 MW e NGCC Power Plant. Based on January 2006 prices. Propylene carbonate Fluor solvent O Tetrahydrothiophenedioxide Sulfolane O Tributyl phosphate Estasolvan O C h e m i c a l M i x e d P h y s i c a l 9

11 Gas solubility data at 1 atm, 25 C (-30 C methanol), vol gas/vol liq Gas Selexol Fluor solvent Purisol Methanol H CO C C CO C COS NH H 2 S nc H 2 O HCN Bucklin and Schendel (1985) Hochgesand (1970) 10

12 1 st generation pre-combustion capture: CO 2 CATCHUP project of Nuon CO 2 removal from side stream of existing IGCC plant in Buggenum, The Netherlands Water-gas-shift section + physical CO 2 sorbent ECN involved in conceptual design and catalyst testing

13 Catch-Up Pilot Plant, Buggenum Picture: Vattenfall 12

14 13 New Developments

15 Efficiency reduction (% points) pre-combustion: efficiency penalty capture Losses due to CO 2 capture in IGCC with physical solvent 4 2 3,5 3 2,5 2 1,5 1 0,5 0 CO2 2 compression CO-Shift Lost GT-work CO2 2 separation

16 Improvements in CO 2 solvent process Shell/Procede TNO New combinations of amines Membrane-assisted desorption TU Delft Ionic liquids 15

17 Advanced Shift: New scheme developed by ECN Advanced shift to reduce steam consumption - Overall steam/co ratio reduced to 0,64 Water 25 o C, 28 bar 306 o C Shifted Syngas 480 o C 380 o C 337 o C IP Steam 325 o C, 28 bar R1 R2 R3 R4 250 o C 250 o C 250 o C H 2O/CO = H 2O/CO = H 2O/CO = o C o C o C 250 o C H 2O/CO = 2.4 Overall Steam/CO = 0.64 Split fraction 1 = 0.35 Syngas 210 o C, 28 bar S Split fraction 2 = 0.27 Split fraction 3 = 0.23 Split fraction 4 = 0.15 Bypass = 0.00 Syngas Bypass Carbo et al (2009) Int J Greenhouse Gas Ctrl 3 (6)

18 Sorption-Enhanced Water-Gas Shift (SEWGS) 400 C, 30 bar Hot separation High H 2 recovery High CO 2 /CO rejection 17

19 CO + H 2 O CO 2 + H 2 Syngas WGS 2%-6% CO H 2 & CO 2 WGS Separation H 2 CO 2 18

20 CO + H 2 O CO 2 + H 2 Syngas WGS 2%-6% CO H 2 SEWGS 400 C 25 bar CO 2 19

21 SEWGS principle and Materials CO 2 CO + H 2 O H 2 CO 2 CO CO 2 2 CO 2 CO 2 sorbent catalyst sorbent CO 2 1 cm Mg 6 Al 2 (OH) 16 CO 3.4H 2 O Al(OH) 6 - octahedron Mg(OH) 6 -octahedron Fe-Cr H 2 O CO 3 2- Promoted with K 2 CO 3 Hydrotalcite (layered clay) 20

22 The SEWGS process; Hot PSA Adsorption regeneration cyclic, multi bed process with HTC C, 1-30 bar High pressure, hot hydrogen Less heating/cooling steps 21

23 SEWGS Test Rigs 2 m single column, 38 mm ID Design conditions: Tmax: 550 C Pmax: 31 bara Feed gases: CH 4, CO, CO 2, H 2, H 2 S, N 2, Steam Six, 6 m high, 38 mm ID columns 48 valves 22

24 SEWGS: Sorbent development LT tests showed the stability of the working capacity as well as shift activity of ALKASORB during 5000 cycles, at a minimal steam to carbon ratio (2 mole/mole). Hence, it was demonstrated that the SEWGS process does not require a shift catalyst, which brings substantial economic and technical benefits. ALKASORB captures also H 2 S along with the CO 2 without significant loss of capacity. 23

25 CO2 in top product (% dry) SEWGS: Alkasorb sorbent is stable 1 Van Selow et al (2010) GHGT-10, Amsterdam cycle no. 24

26 Sufficient WGS activity before CO 2 breakthrough 400 C 30 bar 40 % H 2 O 17 % CO 17 % H 2 20% CO ppm H 2 S Van Dijk et al (2011) Int J Greenhouse Gas Cntrl 5 (3)

27 Efficiency reduction (% points) Pre combustion: Effect of SEWGS and a-wgs on efficiency penalty Losses reduction 4 2 3,5 3 2,5 2 1,5 1 0,5 0 CO2 2 compression CO-Shift Lost GT-work CO2 2 separation

28 Performance comparison IGCC, ~400 MW e No cap Selexol SEWGS Net Efficiency % CO 2 avoidance % Specific energy use GJ/ton avoid Cost of CO 2 avoided, [ /t CO2 ] 40 <30 Gazzani et al. GHGT-10 27

29 Market share Future of SEWGS? Commercial Product R&D CAESAR Demonstration Upsca ling CAESARION Time

30 Scale-up Relative Productivity Relative Vessel Diameter Relative Vessel Length, Superficial Gas Velocity, Residence Time, Cycle Time, Pressure Drop 29

31 Conclusions Physical solvents are attractive for pre-combustion CO 2 capture in IGCC plants Many Rectisol and Selexol units in operation Efficiency penalty for CO 2 capture can be reduced Improved solvents, membrane contacters Reduction of steam demand for WGS Process intensification (sorption-enhanced reactor) 30

32 Acknowledgements caesar.ecn.nl 31