Chalmers University of Technology

2nd Post-Combustion Capture Conference Bergen, Norway

19 Sept, 2013

Henrik Jilvero Carbon Capture and Combustion Group

Department of Energy Technology Chalmers University of Technology

Avoiding ammonia slip from ammonia-based post-

combustion - Evaluation of reduction methods

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Reduce ammonia slip

2 3 4 56

7 8

19

To stack

Pure CO2

HEALTH ENVIRONMENT

• Eutropification • Soil acidification • Fertilization • Smog

• Respiratory system disease (PM2.5) • Eye/Skin/Throat irritation

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Ammonia concentrations

5000-500 ppm Prolonged exposure can lead to death 150-50 ppm Eye/Skin/Throat irritation 50-5 ppm Odor detection 25 ppm Recommended 8-hour exposure limit 7 ppm Recommended long-term exposure limit 300 ppb Recommended exposure limit urban areas

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Equilibrium partial pressure

Temp: 20°C

NH3-CO2-H2O

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Reduction Methods

Method Type

Steam stripping Secondary/Regenerative

Cooled absorption Primary

Staged absorption Primary

Acid wash Secondary/Destructive

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Steam stripping

43

1 2

Beneficial for high CO2 conc.

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Steam stripping

90% CO2 removal

CO2 Capture cycle ~2500 kJ/kg CO2

Rate-based simulations

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Cooled absorption

5

43

1 2

10% NH3

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Staged absorption

43

1c 21b1a

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Staged absorption

Flue gas

CO2-lean

CO2-Rich

Flue gas

CO2-lean

CO2-Rich

a) b)

50000ppm

3000ppm

One-absorber Two-absorber

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Acid wash

1 2

6

Capture with H2SO4

Formation of (NH4)2SO4

Reduction of SOx

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Summary

Reduction method Ammonia reduction potential

Advantage Disadvantage

Steam stripping ~ 100% Full recovery Heat req. Low CO2 conc.

Cooled absorption ~ 60-70% Low cost Chilling req.

Staged absorption ~ 80% High impact Absorber height

Acid wash ~ 100% Byproduct Ammonia destruction

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Summary

1 2

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Conclusion

• Slip is an important design aspect of the absorber

• Trade-off between capture efficiency, ammonia slip and absorber height

• Cost of destructive/regenerative methods?

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Thank you!

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Extra slide 1

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Extra slide 2

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Extra slide 3

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Extra slide 4