Fundación Ciudad de la Energía CIUDEN. Ponferrada 9 th to 13 th September 2013 CIUDEN

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1 Fundación Ciudad de la Energía Ponferrada 9 th to 13 th September 2013 Organised by: Hosted by:

2 NOx emissions experiences in a 30 MWth Circulating Fluidized Bed boiler under oxy combustion conditions Manuel Gómez a, Jesús Ramos a, Benito Navarrete a, Francisco Muñoz a, Beatriz Gil a, Pedro Otero a, Reijo Kuivalainen b, Teri Hiltunen b a Fundación Ciudad de la Energía, II Avenida de Compostilla, nº 2, Ponferrada (León), 24404, Spain b Foster Wheeler Energia Oy, Relanderinkatu 2, FI Varkaus, Finland

3 NO x Types Thermal Fuel Prompt NO x = NO + NO 2 N 2 O as separate component

4 Objective Study of NO and N 2 O emissions at s 30 MWth CFB installation working under both air and oxycombustion conditions

5 Experimental Installation FLY ASH SILO LIMESTON E SILO AMMONIA TANK FLY ASH FEEDING SYSTEM BOILER FEED WATER FUE GAS FLY ASH RECIRCULATION LIMESTONE SAND FUEL FEED SAND SILO FUEL SILO LIMESTONE FEEDING SYSTEM SAND FEEDING SYSTEM FUEL FEEDING SYSTEM FLY ASH SYSTEM MIXER MIXER MIXER PRIMARY OXIDANT FAN SECUNDARY OXIDANT FAN PRIMARY OXIDANT SECUNDARY OXIDANT NATURAL GAS START-UP BURNER SKID OXYGEN BOTTOM ASH

6 Instrumentation O 2 NO/N 2 O measurement Cyclon+Bag Filter AIR FLUE GAS RECIRCULATION

7 Stability Period bed temperature (ºC) STABLE O 2 excess (vol.% wet basis) Steam flow (kg/h) PERIOD flue gas flow (kg/h) SO 2 (ppmv) coal flow (t/h)

8 NO/N 2 O determination Bed Temperature NO N 2 O

9 Operating variables influencing NO and N 2 O emission Temperature Limestone addition Load Oxygen content in the oxidant (FGR ratio) Primary/secondary oxidant distribution

10 Fuel 1- Anthracite Proximate analysis (wt. %) Moisture content (as 4.95 received) Ash (dry basis) Volatiles (dry basis) 7.57 Fix carbon (dry basis) Ultimate analysis (wt. % dry basis) C H 1.95 N 0.79 S 0.98 HHV (Kcal/kg, wet basis) 5040

11 Testing conditions Air/oxy modes Different bed temperatures Different limestone injection rates High load operation 3-5 excess oxygen (vol. % db) Primary/secondary oxidant ratio = (exceptionally )

12 AIR OXY NO ppmv wet Temperature ( C) Ca/S molar ratio

13 AIR OXY N 2 O ppmv wet Temperature ( C) Ca/S molar ratio

14 Fuel 2- Blend: Anthracite/Petcoke (70/30 % weight) Proximate analysis (wt. %) Moisture content (as 4.83 received) Ash (dry basis) Volatiles (dry basis) 8.05 Fix carbon (dry basis) Ultimate analysis (wt. % dry basis) C H 2.42 N 1.06 S 2.24 HHV (Kcal/kg, wet basis) 8381

15 Testing conditions Air/oxy modes Different bed temperatures Different limestone injection rates High load operation 3-5 excess oxygen (vol. % db) Primary/secondary oxidant ratio = (exceptionally )

16 AIR OXY NO ppmv wet Temperature ( C) Ca/S molar ratio

17 AIR OXY N 2 O ppmv wet Temperature ( C) Ca/S molar ratio

18 NH 3 injection 25 % weight water solution Oxy-combustion conditions Limestone injection 3-5 % excess oxygen (vol. % db) Different bed temperatures Primary/secondary oxidant ratio = (exceptionally )

19 NH 3 injection Selected point

20 NO ppmv wet T = 920 T = 904 T = 892 T = 890 T = 888 T = Kg NH 3 /h T = 855

21 N 2 O ppmv wet T = 920 T = 904 T = 892 T = 890 T = 888 T = 865 T = 855 Kg NH 3 /h

22 Preliminary Conclusions NO dominates NO x emission NO emission increases with temperature increase N 2 O emission decreases with temperature increase NO emission increases with limestone addition increase High limestone addition rates do not affect N 2 O emission NH 3 injection decreases NO emission NH 3 injection does not affect N 2 O emission

23 Future research work Validation of these preliminary results Influence of operating conditions Heterogeneous reactions (solid-gas phases) Other fuels. Same behaviour?

24 Acknowledgement The work presented is co-financed under the FP7 FLEXIBURNCFB and the EEPR09-CCS- COMPOSTILLA projects. The European Union is not responsible for any use that may be made of the information contained therein.

25 THANK YOU VERY MUCH FOR YOUR ATTENTION For further information, please contact Manuel Gómez,