CO 2 Emission Reduction Potential and Technological Aspects of the Oxyfuel Technology in Cement Clinker Production Dr.-Ing. Volker Hoenig, Dipl.-Ing. Kristina Koring OCC3 Ponferrada September 2013 OCC3, Ponferrada, September 2013
AGENDA 1 Clinker burning process 2 Integration of the Oxyfuel Technology and design aspects 3 3 I Impact on plant operation t l t ti 4 Impact on material conversion and product quality 5 Cost estimation 6 Summary and Outlook
1. Introduction - Clinker burning process Flue gas 300 - 350 °C 300 350 C Material CO Material CO 2 Raw meal CaCO 3 , SiO 2 , Fuel CO 2 Al 2 O 3 , Fe 2 O 3 Cyclone Cyclone preheater Calciner Cooler exhaust air 200 °C - 350 °C Fuel 850 °C Tertiary air duct 700 - 1000 °C Fuel/ air 700 - 1000 °C 700 1000 C CaCO 3 CaO + CO 2 Rotary kiln 2000 °C Cooling air g Clinker Clinker Cooler
2. General layout Bag filter Heat Storage exchanger CO 2 rich flue gas Transport Exhaust air Mixing cleaning gas CO 2 Compression Raw Material Pre- Condenser heater Raw Mill Fuel Fuel Preparation CO 2 Purification Air In-leaks Pre- calciner Rotary Kiln Rotary Kiln Cooler Clinker Air Gas Mixing Separation Oxidizer Oxidizer Air Air Unit Unit N N 2
2. Retrofitting boundaries • Important aspect for the application of oxyfuel in Europe • Retrofitting an existing burner for oxyfuel application is unlikely, but replacement by a suitable design is possible • Designing a gas-tight two-stage cooler is feasible Designing a gas tight two stage cooler is feasible • False air intrusion could be reduced to the greatest possible extent by overhauling/ replacing inspection doors and similar devices (< 6%) • New safety and controlling devices necessary • Space requirements of ASU/CPU • Conventional behavior in trouble shooting restricted (no opening of doors/flaps in the plant etc ) (no opening of doors/flaps in the plant etc.) Retrofitting is feasible
3. Impact on plant operation • Influence on heat • Air separation and transfer and CO 2 purification are temperature profiles p p energy intensive gy • Adaptation of plant • Energetic integration operation necessary required Add. Plant Gas Aggre- Aggre- Property gates Plant Recircu- Modifica- • New installations • Recirculation rate: lation rate tion tion F Fraction of total flue ti f t t l fl • Retrofitting existing gas, which is plants reciculated to process • Setting of oxygen level
3. Impact of gas properties ∆ 50 - 100 C 2200 2200 Stress on Stress on refractory 2000 tur [°C] n °C 1800 Gastemperat emperature i 1600 1400 G 1200 1200 Gas te ∆ 150 C 1000 Kiln length Ofenlänge Ofenlänge Reference: Air operation Referenz: Luftbetrieb Rezirkulierung, 21 Vol.-% O2 O 2 Recirculation Recirculation O 2 O 2 Rezirkulierung, 25 Vol.-% O2 Rezirkulierung, 23 Vol.-% O2 Recirculation Potential increase of Potential increase of coating formation
3. False air ingress and flue gas composition 88 Influencing parameters: 87 • O Oxygen purity n flue gas [vol.%] 86 • False air ingress 85 • • Oxygen excess Oxygen excess 2-concentration in 84 • Fuel type 83 CO2 82 False air reduction of 6 - 8 % technically feasible by improved maintenance without 81 additional sealing methods (like e.g. waste g ( g 1 2 3 4 5 6 7 8 9 10 air-ingress [% of flue gas] gas flushed systems) Oxidizer: 95 vol.% O2, 3.5 vol.% O2 excess Oxidizer: 98 vol.% O2, 3.5 vol.% O2 excess Oxidizer: 99.5 vol.% O2, 3.5 vol.% O2 excess
3. Flue gas recirculation 3150 Plant modifications necessary due to y Energiebedarf 3100 3100 reduced volume flow y demand in preheater 3050 g Klinker inker ermal energy in kJ/kg 3000 3000 Thermischer E in kJ/kg cl 2950 2900 2900 The T 2850 0.3 0.35 0,3 0,35 0,4 0.4 0,45 0.45 0.5 0,5 0,55 0.55 0.6 0,6 Recirculation rate Recirculation rate Rezirkulationsrate Rezirkulationsrate Fuel energy demand is depending on flue gas recirculation and treatment Decreasing recirculation rate includes less flue gas losses D i i l ti t i l d l fl l
3. Energetic consideration 950 ker 850 850 in kJ/kg clink Raw material drying Power generation kJ/kg Klinker 750 650 as enthalpy i enthalpie in External heat 550 exchanger 450 Ga 350 Gas 250 0,3 0,35 0,4 0,45 0,5 0,55 0,6 0.3 0.35 0.4 0.45 0.5 0.55 0.6 R Rezirkulationsrate i k l ti t Recirculation rate Flue gas, preheater Abgas Vorwärmer Kühlerabgas, Stufe 2 Cooler exhaust air Recirculation rate determines the energy distribution and therefore waste heat recovery potential
3. CO 2 emission reduction potential Capture rates of 88 to 99 % feasible Capture rate independent of recirculation rate Reduction of capture rate possible by Exhaust gas of the CO 2 purification unit (- 1 to 10 % capture) Additional firing for raw material drying (- 1 to 2 % capture) Leakage at cooler stage sealing (up to - 1 % capture) Recirculation Rezirkulation Rezirkulation Exhaust gas of Abluft von Abluft von CPU der CPU der CPU Entsäuerung Entsäuerung Calcination CO 2 for CO 2 zum CO 2 zum storage/reuse Speicher Speicher Primärgas Primärgas Primary gas Kühl Kühl Kühlerabluft Kühlerabluft bl ft bl ft Cooler Brennstoff Brennstoff Fuel leakage Potential additional mögliche mögliche firing Zufeuerung Zufeuerung
4. Kiln operation – Impact on solid conversion 70 60 60 50 [wt.%] 40 olid content 30 20 s 10 0 kil kiln length l th Reference, C3S Reference, C2S Recirculation 21 vol.% O2, C3S Recirculation 21 vol.% O2, C2S Recirculation 23 vol.% O2, C3S Recirculation 23 vol.% O2, C2S
4. Limiting factors by quality and durability requirements • No serious influence on clinker composition • Slight differences in cement properties (caused by Fe 2+ ) are in range of assured (caused by Fe 2+ ) are in range of assured quality • No negative influence on basic refractory material detected material detected • Using non-basic materials an increasing thermo-chemical reaction expected • Adaption of refractory brickwork necessary p y y • Long-term test for evaluation advisable [49-442] Ca3SiO5 von unten nach oben: [33-302] Ca2SiO4 / Larnite 14000 V1K1, 2011-i_MVT-03280 [30-226] Ca2(Al,Fe)2O5 / Brownmillerite V6K1, 2011-i_MVT-03285 [38-1429] Ca3Al2O6 (cubic) [32-150] Ca3Al2O6 (ortho) V11K1, 2011-i_MVT-03290 [45-946] MgO / Periclase V16K1, 2011 i_MVT 03295 V16K1, 2011-i MVT-03295 [37 1497] C O / Li [37-1497] CaO / Lime V21K1, 2011-i_MVT-03305 12000 [37-1496] CaSO4 / Anhydrite V26K1, 2011-i_MVT-03310 [46-1045] SiO2 / Quartz, syn [49-1807] Ca5(SiO4)2SO4 / Ternesite P-2011/0372, A11/057 (Range 1) 10000 No barriers expected from Absolute Intensity 8000 clinker quality and refractory 6000 4000 durability durability 2000 2000 0 10.0 20.0 30.0 40.0 50.0 60.0 2Theta
4. Impact on decarbonation 1 0,8 Increase of temperature arbonation [-] Conventional level: operation 0,6 • Problems with degree of deca ∆ 80 K burning low-calorific 0,4 fuels in calciner may occur 0 2 0,2 d • Higher risk of coating Oxyfuel operation formation in the 0 calciner 650 700 750 800 850 900 950 1000 temperature [°C] pCO2 = 0,2 bar pCO2 = 0,4 bar pCO2 = 0,6 bar pCO2 = 0,8 bar pCO2 = 0,97 bar
4. Impact on cement properties Strenght development Setting behaviour 120 110 105 100 100 strength in % heat in % % 95 80 90 85 85 60 60 hydration compressive 80 40 75 70 20 65 65 60 0 samples 1 -5 after 48 h 2 days 28 days Standard Conditions Oxyfuel Conditions Standard condition Standard condition Oxyfuel condition Oxyfuel condition Burning: CO2/ Cooling:Standard Burning: CO2/ Cooling:Standard Burning: Standard/ Cooling: CO2 Burning: Standard/ Cooling: CO2 Burning: CO2/ Cooling: Standard Burning: Standard/ Cooling: CO2 Testing at five clinker types of different reactivity No influence on chemical-mineralogical composition Cement properties are not influenced
5. Cost Estimation Investment costs New installation (2 mio tpy annual clinker capacity): 2030: 2030: 330 - 360 Mio € 330 - 360 Mio € (Reference: 260 Mio €) (Reference: 260 Mio €) 2050: 270 - 295 Mio € Remark: Costs for demonstration plant in 2020 would be significantly higher significantly higher Operational costs Fixed operating Misc Raw materials costs plus 8 to 10 €/t clinker on top of base case Coal transport and storage excluded Power Total cost increase of about 40 % Additional costs per ton of avoided CO 2 : 33 - 36 €/t CO2
6. Summary and Outlook Oxyfuel technology in the cement clinker burning process technically feasible Retrofit of existing plants is possible Cement properties are not impaired Optimum operational mode depends on local specification of the cement Opt u ope at o a ode depe ds o oca spec cat o o t e ce e t plant (e.g. raw material moisture) Capture rate between 88 and 99 % Production costs are increased by Production costs are increased by ~ 40% (excl. transport and storage) 40% (excl transport and storage) Oxyfuel technology will not be available in the cement sector before 2030 ECRA CCS Project Phase IV.A is dealing with the further detailing of previous phases and the concept study of an oxyfuel pilot plant
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