Ca-looping forpost-combustion CO 2 capture"

Transcription

1 CSIRO PCC Science& Techonology Seminar 26 March, CSIRO Energy Centre, Newcastle Ca-looping forpost-combustion CO 2 capture" Borja Arias Rozada borja@incar.csic.es CO 2 Capture Group Spanish Research Council (INCAR-CSIC)

2 OUTLINE PostcombustionCalcium Looping concept Pilot plant results from the CaOling project -Testing lab scale facilities (<30 kw th ) -Testing results from a 1.7 MW th pilot Conclusions

3 Ca-looping: The main process concept CaO CaCO 3 Flue gas without CO 2 CO 2 Carbonator 650º-700ºC Heat OUT Heat IN Calciner T>900ºC Flue gas with CO 2

4 Main process concept: Post-combustion CO 2 capture Power OUT Flue gas without CO 2 Power OUT Concentrated CO 2 STANDARD POWER PLANT CO 2 SO 2 Flue Gas CARBONATOR 650ºC CaCO 3 CaO OXY-CFB CALCINER >900ºC O 2 Coal Air CaCO 3 CaO Purge Coal ASU Air Some features of postcombustion Ca-looping : Low energy penalty (6-7 net points)/low cost per ton CO 2 captured Purge of CaO: synergies with cement industry and others (i.e. desulfurization of FG) Low cost sorbent precursor (low toxicity of materials involved) Pre-treatment of flue gas no needed (SO 2 co-capture) Benefits and limitations of large scale CFBCs (including oxy-cfb) N 2 Shimizu et al, 1999, Trans. IChemE 77A, 62 68

5 Advanced CaL concept: power plant with inherent CO 2 capture Flue gas with CO 2 Power OUT Concentrated CO 2 Hot CaO CaO COMBUSTOR T>1000 ºC CALCINER 900 ºC CARBONATOR 650º CaO CaCO 3 Coal Air CaCO 3 CaO Flue gas with CO 2 Some advantages of a Ca-L power plant calcining with hot CaO : No air separation unit required, no energy penalties other than compression and aux. Key CFBC equipment already available, but high combustion temperatures asks for coal quality High solid circulation required and new scaling up issues for FB calciner. Martínez et al, 20011Int. J. of Greenhouse Gas Control 5, (

6 OUTLINE PostcombustionCalcium Looping concepts Pilot plant results from the CaOling project -Testing lab scale facilities (<30 kw th ) -Testing a 1.7 MW th pilot Conclusion

7 Consortium agreement: CaOling project 23 FEB APR JUL 2008 DEC 2009 Development of postcombustion CO 2 capture with CaO in large testing facility European Union 7th Framework Programme-FP7

8 Validation of Ca-looping for post-combustion CO 2 capture at small facilities Small pilot plant at INCAR- CSIC (30 kwt) CO 2 capture efficiency in CFB carbonator Equilibrium Experimental Capture efficiency (%) Stop loop-seal Circulation measurement 21:15 21:25 21:35 21:45 21:55 22:05 22:15 22:25 22:35 22:45 time (h:min) Calciner reactor Carbonator reactor Main features: Two CFB reactors (Height~6.5 m, diameter=100 mm) Electrically heated Continuous monitoring temperature, pressure drops, gas composition etc) Occasional measurement of solid circulation rates More than 450 hours of operation N. Rodríguez, et al. AIChE Journal, 57, ,2010

9 Results: Characterization of the carbonator reactor CARBONATOR REACTOR MODELLING CO 2 reacting with CaO in the bed = CO 2 removed from the gas phase E Initial assumptions carbonator reactor: Instantaneous and perfect mixing of the solids Plugflowforthegasphase ( ) N τactive = carb = τactiveϕks fco2 fe F CaO CO2 f a X ave EXPERIMENTAL RESULTS FROM THE SMALL FACILITIES AT INCAR-CSIC AND IFK (10 s kw)

10 Scaling up: La Pereda CO 2 Ca-L pilot plant CSIC lab-plant X m 2008: 30 kwt 2011: 1,7 MWt

11 La Pereda CO 2 pilot plant: Current status Status of the pilot plant -Building finished in September Start of cold commissioning: October Start of hot commissioning: January Operational hours with coal combustion (dual fluidized bed mode): ~ 1500 h -Operational hours in CO 2 capture mode : ~ 310 h (approximately 120 h with the calciner working under oxy-fuel conditions)

12 La Pereda CO 2 pilot plant: Power plant integration

13 RESULTS Range of conditions during the CO 2 capture test: Carbonator temperature (ºC) Carbonator superficial gas velocity (m/s) Inlet CO 2 volume fraction to the carbonator Inlet SO 2 concentration to the carbonator (mg/m 3 ) Inventory of solids in the carbonator (kg m -2 ) Maximum CO 2 carrying capacity of the solids Calciner temperature (ºC) ºC Inlet O2 volume fraction to the calciner Inlet CO2 volume fraction to the calciner CO 2 capture efficiency SO 2 capture efficiency

14 Results from the 1.7 MWth CaL pilot plant of la Pereda Typical examples of steady state tests - Inventory of solids in carbonator = kg/m2 - Average carbonator temperature= 660 ºC -Xave = CO2 capture efficiency ECO2 eq ECO2 CO2 out CO2 in Deliverate alteration of the solid circulation CO2 (%vol) 0 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 0

15 RESULTS Results from FROM the THE 1.7 MWth 1.7 MWth CaL CALCIUM pilot plant LOOPING of la Pereda PILOT PLANT OF LA PEREDA SO 2 capture in the Ca-looping facility ESO ESO2 carb 0.06 XCaSO ESO2 calc Experimental 0.03 Calculated :00 5:00 7:00 9:00 11:00 13:00 15:00 0

16 Results from the 1.7 MWth CaL pilot plant of la Pereda Evolution of sorbent utilization with lifetime of particles in the system Xave, XN, X CaSO Xave XN (Grasa et al 2006) XCaSO4 experimental XCaSO4 calculated CaO utilization ECO ECO2 eq ECO2 Carbonator inventory Inventory of solids (kg/m 2 ) :10 11:20 11:30 11:40 11:50 12: N th Number of times that the inventory of CaO is carbonated up to the maximum CO2 carrying capacity N F E t CO2 carb( t) th = 0 NCaXave dt

17 MAIN CONCLUSION A flexible experimental facility is in operation in La Pereda Power Plant aiming to validate the technology in the 1MW s size CO 2 capture efficiencies over 90% achievable in a CFB carbonator reactor operating with standard CaO solids, bed inventories, gas velocities, solid circulation rates and reaction conditions in the carbonator and calciner reactors(oxyfuel coal combustion) SO 2 captureinthecfbcarbonator isover95% The concept of post-combustion Ca-looping in continuous mode of operation has been successfully proven with two interconnected CFBCs at the MWth scale

18 CSIRO PCC Science& Techonology Seminar 26 March, CSIRO Energy Centre, Newcastle Ca-looping forpost-combustion CO 2 capture" Borja Arias Rozada borja@incar.csic.es Thanks for your attention The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ ) under GA CaOling Project and from Asturian PCTI.