CO 2 Emission Reduction Potential and Technological Aspects of the - - PowerPoint PPT Presentation

CO2 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 I t l t ti 3 Impact on plant operation 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 Material CO Raw meal Cyclone 300 350 C Material CO2 Fuel CO2 CaCO3, SiO2, Al2O3, Fe2O3 Cyclone preheater Calciner Cooler exhaust air Tertiary air duct Fuel/ air Fuel 700 - 1000 °C 200 °C - 350 °C 850 °C 700 - 1000 °C Cooling air Rotary kiln 2000 °C 700 1000 C Clinker CaCO3  CaO + CO2 Cooler g Clinker

• 2. General layout

Heat exchanger Bag filter CO2 rich flue gas Storage

Raw Material

Transport CO2 Compression Mixing gas Exhaust air cleaning Pre- heater Raw Mill Fuel Preparation Fuel CO2 Purification Condenser Rotary Kiln Pre- calciner Air In-leaks Air Rotary Kiln Cooler

Clinker

Oxidizer Air Separation Unit N Gas Mixing Air Oxidizer Unit N2

• 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
• Air separation and

CO2 purification are energy intensive

• Influence on heat

transfer and temperature profiles gy

• Energetic integration

required p p

• Adaptation of plant
• peration necessary

Gas

• Add. Plant

Aggre- Property Aggre- gates

• New installations
• Recirculation rate:

F ti f t t l fl

Plant Modifica- tion Recircu- lation rate

• Retrofitting existing

plants

Fraction of total flue gas, which is reciculated to process

• Setting of oxygen level

tion

• 3. Impact of gas properties

Stress on

2200

∆ 50 - 100 C

Stress on refractory

1800 2000 2200

tur [°C]

n °C

1200 1400 1600

Gastemperat

emperature i

1000 1200

Ofenlänge G

∆ 150 C

Kiln length

Gas te

Potential increase of

Ofenlänge

Referenz: Luftbetrieb Rezirkulierung, 21 Vol.-% O2 Rezirkulierung, 25 Vol.-% O2 Rezirkulierung, 23 Vol.-% O2 O2 O2 O2 Reference: Air operation Recirculation Recirculation Recirculation

Potential increase of coating formation

• 3. False air ingress and flue gas composition

87 88

Influencing parameters: O

85 86

n flue gas [vol.%]

• Oxygen purity
• False air ingress
• Oxygen excess

83 84

2-concentration in

• Oxygen excess
• Fuel type

81 82 1 2 3 4 5 6 7 8 9 10

CO2

False air reduction of 6 - 8 % technically feasible by improved maintenance without additional sealing methods (like e.g. waste

air-ingress [% of flue gas]

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

g ( g gas flushed systems)

• 3. Flue gas recirculation

3100 3150 Plant modifications necessary due to 3000 3050 3100 Energiebedarf g Klinker y reduced volume flow in preheater

y demand inker

2900 2950 3000 Thermischer E in kJ/kg

ermal energy in kJ/kg cl

2850 2900 0,3 0,35 0,4 0,45 0,5 0,55 0,6 Rezirkulationsrate T

Recirculation rate

0.3 0.35 0.4 0.45 0.5 0.55 0.6

The

• Fuel energy demand is depending on flue gas recirculation and treatment

D i i l ti t i l d l fl l

Rezirkulationsrate

Recirculation rate

• Decreasing recirculation rate includes less flue gas losses

• 3. Energetic consideration

850 950

ker

650 750 850

kJ/kg Klinker

Power generation Raw material drying

in kJ/kg clink

450 550

enthalpie in

External heat exchanger

as enthalpy i

250 350 0,3 0,35 0,4 0,45 0,5 0,55 0,6

R i k l ti t Gas

0.3 0.35 0.4 0.45 0.5 0.55 0.6

Ga

Rezirkulationsrate

Abgas Vorwärmer Kühlerabgas, Stufe 2

Recirculation rate

Flue gas, preheater Cooler exhaust air

Recirculation rate determines the energy distribution and therefore waste heat recovery potential

• 3. CO2 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 CO2 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)

Rezirkulation Rezirkulation

Recirculation

Abluft von der CPU Abluft von der CPU

Exhaust gas of CPU

Entsäuerung Primärgas CO2 zum Speicher Kühl bl ft Entsäuerung Primärgas CO2 zum Speicher Kühl bl ft

Calcination Primary gas CO2 for storage/reuse

Brennstoff Kühlerabluft mögliche Zufeuerung Brennstoff Kühlerabluft mögliche Zufeuerung

Fuel Cooler leakage

Potential additional firing

• 4. Kiln operation – Impact on solid conversion

60 70 40 50 60

[wt.%]

20 30

• lid content

10

s kil l th kiln length

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 Fe2+) are in range of assured (caused by Fe2+) 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

14000

von unten nach oben: V1K1, 2011-i_MVT-03280 V6K1, 2011-i_MVT-03285 V11K1, 2011-i_MVT-03290 V16K1, 2011-i MVT-03295 2000 4000 6000 8000 10000 12000 Absolute Intensity

V16K1, 2011 i_MVT 03295 V21K1, 2011-i_MVT-03305 V26K1, 2011-i_MVT-03310

No barriers expected from clinker quality and refractory durability

2Theta 10.0 20.0 30.0 40.0 50.0 60.0 2000

durability

• 4. Impact on decarbonation

1

Increase of temperature level:

• Problems with

0,6 0,8

arbonation [-]

Conventional

• peration

burning low-calorific fuels in calciner may

• ccur

0 2 0,4

degree of deca

∆ 80 K

• Higher risk of coating

formation in the calciner

0,2 650 700 750 800 850 900 950 1000

d

Oxyfuel

• peration

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

120

105 110

Strenght development Setting behaviour

60 80 100

strength in % 85 90 95 100 heat in % %

20 40 60

compressive 65 70 75 80 85 hydration

Standard condition Oxyfuel condition

2 days 28 days 60 65

Standard Conditions Oxyfuel Conditions Burning: CO2/ Cooling:Standard Burning: Standard/ Cooling: CO2

samples 1 -5 after 48 h

Standard condition Oxyfuel condition Burning: CO2/ Cooling: Standard 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

New installation (2 mio tpy annual clinker capacity): 2030: 330 - 360 Mio € (Reference: 260 Mio €) Investment costs 2030: 330 - 360 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 costs Raw materials Misc

plus 8 to 10 €/tclinker on top of base case

transport and storage excluded

Coal Power

Total cost increase of about 40 % Additional costs per ton of avoided CO2 : 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

• pe at o a
• de depe ds o
• ca spec cat o
• t e ce

e t plant (e.g. raw material moisture)

• Capture rate between 88 and 99 %
• Production costs are increased by

40% (excl transport and storage)

• Production costs are increased by ~ 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

Thank you for the attention!

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