CO2 Capture and Storage: Options and Challenges for the ... · PDF fileChallenges for the Cement Industry ... preheater cooler The energy balance of a cement kiln will be ... 2 Capture

CO2 Capture and Storage: Options and Challenges for the Cement Industry

Martin Schneider, Düsseldorf, Germany

CSI Workshop

Beijing, 16 – 17 November 2008

CO2 abatement costs will tremendously increaseGlobal cost curve for greenhouse gas abatement measures beyond „business as usual“; greenhouse gases measured in GtCO2e1

Source:McKinsey-Quarterly 1/2007

CO2 abatement costs will tremendously increase

1. GtCO2e=Giga tonnes of CO2 equivalent, „business as usual“ based on emission growth driven mainly by increasing demand for energy2. tCO2e= tonne of CO2 equivalent3. Measures costing more than 40$ were not the focus of this study4. Atmosperic concentrations of all greenhouse gases recalculated into CO2e in ppm5. Marginal costs of avoiding 1tonne of CO2e in each abatement scenarion

Global cost curve for greenhouse gas abatement measures beyond „business as usual“; greenhouse gases measured in GtCO2e1

Source:McKinsey-Quarterly 1/2007


1. Introduction

2. The cement clinker burning process

3. General CO2 capture technologies

4. Applicability of CO2 capture technologies to the clinker burning process – ECRA research project

5. CO2 transport and storage

6. Summary and outlook

CO2 Emissions from Large Stationary Sources

33Other Sources

50Oil and Gas Processing

379Petrochemical Industry

646Iron and Steel Industry

798Refineries

932Cement Production

10,539Power Plants

Emissions [Mt CO2/yr] *Process

*IPCC Special Report „Carbon Dioxide Capture and Storage“ (2005)


1. Introduction



4. Applicability of CO2 capture technologies to the clinker burning process - ECRA research project



The cement clinker burning process

preheater exitgas

fuel

clinker

fuelprimary

air

cooler exhaust gas

kiln feed

secondary airtertiary air

cooling air

De-carbonisation

56%

Fuel combustion

38%

Electricity use6%

CO2 emissions from the clinker burning process

• Calcination of raw material:

CaCO3 → CaO + CO2

– 0,525…0,555 kg CO2/kg clinker

• Fuel combustion

– 0,280…0,415 kg CO2/kg clinker

• Electricity use

Options to control the CO2 emissions from the clinkerburning process

Conventional technologies

– Reduction of clinker / cement ratio

– Decarbonated raw materials

– Utilization of biomass

– Energy efficiency measures

CO2 capture technologies

– CO2 capture at large stationary sources

– Transport of CO2 to appropriate storage sites

– Long-term underground storage of CO2

Limited reduction potential left

Not state of the art and very expensive


1. Introduction






General CO2 capture technologies

• Pre-combustion capture

• Oxy-fuel combustion capture

• Post-combustion capture

• Others (e.g. carbonate looping, ....)

Pre-combustion technologies (1)

coal

biomassgasification

processH2

CO2

combustion process

storage

naturalgas

reformingprocess

H2

CO2

combustion process

storage


Scheme of gasification process:• Partial oxidation for heat supply

CH4 + ½ O2 CO + H2

• Gasification of solid carbonaceous matter2 C + O2 2 COC + H2O CO + H2

• CO shift for hydrogen synthesisCO + H2O CO2 + H2


Level of implementation:

• Steam reforming is the predominant technology for H2 production worldwide

• IGCC (Integrated Gasification Combined Cycle) demonstration plants since the 1970s

• IGCC can be realized with or without CO2 capture

• Several full-scale IGCC projects with CO2 capture are being planned in the power sector

Oxy-fuel combustion

• Elimination of nitrogen from the flue gas

• Combustion in pure oxygen or a mixture of oxygen and a CO2-rich recycled flue gas

• Flue gas consists mainly of CO2 and water vapour

• Flue gas cooling to condense the water

• Concentrated CO2 stream is compressed, driedand purified before delivery into a pipeline for storage

General scheme of Oxy-fuel combustion processes

air

fuel

air separation N2

O2combustion

processexhaustgas (CO2 enriched)

exhaust gas recirculation

atmosphere

Post-combustion technologies

• Flue gas from combustion processes is passed throughequipment which separates most of the CO2

• Impurities in the flue gas stream are very important for thedesign of the plant and affect the costs significantly(low dust, NO2 and SO2 concentration required)

• End-of-pipe technology

• Commercially available (absorption technologies)

• Retrofit to existing plants possible

Different types of post-combustion technologies

• Absorption technologies:- Chemical absorption- Physical absorption

• Membrane processes

• Solid sorbent processes:- Physisorption processes- Mineral carbonation- Carbonate looping

Absorption technologies are most developed today

• Chemical absorption:- Amines (e.g. MEA) or inorganic salt

solutions (e.g. K2CO3) as absorbent - High energy demand for solvent

regeneration- Very low dust, SO2 and NO2

concentration required- CO2 capture costs for new coal-fired

power plants: 29-51 $/t CO2

• Physical absorption:- Solvents as absorbent

(e.g. methanol)- High CO2 content required ↑ CO2 capture by chemical absorption

(fertilizer plant in Malaysia)

Simplified flow sheet of chemical absorption process for CO2 capture


1. Introduction






ECRA research project on CCS

Carbon Capture technology –Options and Potentials for the Cement Industry

• Phase I: Literature and scoping study (2007)

• Phase II: Study about technical and financial aspects of CCS projects, concentrationg on oxy-fuel and post-combustion(autumn 2007- summer 2009)

• Phase III: Laboratory-scale / small-scale research activities(autumn 2009 – summer 2011)

• Phase IV: Pilot-scale research activities (time-frame: 2-3 years)

Assessment of CO2 Capture Technologies

new plants,

retrofitno

Post-Combustion

new plantsyesOxy-fuel

noyesPre-

Combustion

Applicable to the clinker

burningprocess ?

Effects on burningprocess

Raw material generated CO2

Fuel generatedCO2

Applicability of pre-combustion technologies to the clinker burning process (1)

Hydrogen from syngas of gasification processes as fuel for cement kiln burners?• Hydrogen has different properties

as actual fuels:- handling/feeding must be solved- pure H2 cannot be used in

kiln firing• H2 flames have low heat transfer

by radiation- temperature profile in the kiln- injection of raw meal or clinker

dust

Hydrogen from syngas of gasification processes as fuel for cement kiln burners?• New combustion technologies

required:- non-carbonaceous flame

ingredients- new burner technologiesfor increasing heat transfer

• Only abatement of fuel CO2is captured

1/3 of total CO2 emissions

Hardly promising for clinker burning process


air

fuelraw material

air separation N2

O2

clinker burningprocess

clinker

exhaustgas (CO2 enriched)

exhaust gas recirculation

atmosphere


• On-site oxygen production required (air separation plant)

• New combustion technologies required, e.g.:

– Oxy-fuel burner

– Waste gas recirculation

• Modification of plant design, e.g.:

– Dimension of kiln, cooler, preheater

– Gas recirculation including dedusting, cooling

• Impact on reactions (e.g. decarbonation) and clinker quality


Influence of CO2 partial pressure on decarbonation

The equilibriumtemperature of thedecarbonation of calcium carbonateand cement rawmeals will beincreasedby 50 – 70 K

kiln meal 2

0,0

0,2

0,4

0,6

0,8

1,0

650 700 750 800 850 900 950 1000

temperature [°C]

degr

ee o

f dec

arbo

natio

n

pCO2 = 0,2 barpCO2 = 0,4 barpCO2 = 0,6 barpCO2 = 0,8 barpCO2 = 0,97 bar

Modeling of the clinker burning process

• clinker burning process (dry)• chemical / mineralogical reactions• heat transfer• process technology• energy and material balances

(approximately 1000 balance spaces)

balance spaces

The gas temperature profile in the rotary kiln will be changed by higher CO2 concentration in combustion “air”

1000

1200

1400

1600

1800

2000

2200

2400

kiln length

tem

pera

ture

[°C

]

0 Vol-% 10 Vol-% 20 Vol-% 30 Vol-% 40 Vol-% 50 Vol-% 60 Vol-% 70 Vol-% 79 Vol-% reference

CO2

CO2

CO2

CO2

CO2

CO2

CO2

CO2

CO2

The maximum temperature of flame gases and raw meal in the sintering zone will be decreased by oxy-fuel operation

1400

1600

1800

2000

2200

0 10 20 30 40 50 60 70 80

kiln feedgas

tem

pera

ture

[°C

]

1450°C

CO2 concentration in tertiary-/secondary “air" [Vol-%]

60

62

64

66

68

70

72

0 10 20 30 40 50 60 70 80

degr

ee o

f effi

cien

cy [%

]

72

76

80

84

88

degr

ee o

f effi

cien

cy [%

]

preheater cooler

The energy balance of a cement kiln will be significantly affected by the oxy-fuel operation

CO2 concentration in combustion „air“ [Vol-%]

Applicability of post-combustion capture to the clinkerburning process

air

fuel

raw material

clinker burningprocess

CO2absorption

clinker

exhaust gas (CO2 poor)

transport, storage

CO2

Application of CO2 capture with amine absorption in a Norwegian 3000 t/d cement plant (pilot study)

Technical requirements:• NOx abatement with SNCR• SO2 abatement with wet

scrubber• waste heat recovery boiler• CO2 capture amine absorption• Amine recovery with stripper• Gas fired boiler

45Total costs in €/t CO2

32Operating costs in mio €/year

110

87

322828

Investment costs in mio €thereof:- waste gas cleaning- waste heat recovery boiler- CO2 capture- CO2 drying and compression - boiler

2006 data


1. Introduction



4. Applicability of CO2 capture technologies to the clinker burning process – ECRA research project



CCS: CO2 capture, transport and storage

Transport of CO2 is state of the art – but for considerably smaller quantities

CO2 transport ship

CO2 pipeline

Transport costs through pipelines are determined by distance and mass flow rate

Storage Options for CO2

• CO2 enhanced oil recovery

• CO2 enhanced gas recovery

• CO2 enhanced coal-bed methane recovery (ECBM)

• Storage in depleted oil and gas fields

• Storage in deep saline aquifers

• Other storage options

Storage Options for CO2

CO2 storage with enhanced oil recovery (EOR)

recycled CO2

productionwell

CO2 injection

CO2 water oil

Source: IEA 2004

International CO2 Storage projects

Exhaust gas composition – effect on CCS

Impurities

– SO2

– NOx

– H2S

– H2O

Known effects on

– density of compressed CO2

– compressibility

– water solubility

– flow rate

• No significant difference between CO2 from cement plants and power plants

• Small impact of efficiency

Criteria for storage site selection

Trapping mechanisms:

• Physical: statigraphic and structual

• Physical: hydrodynamic

• Geochemical

• Others

Source: Baele, J.-M., 2008

Suitable storage formation - Belgium, an example

Source: P.C.H., 2001

Campine Basin:

• Potential sequestrationin coal seams

• Subsequent coal bed –methane production


1. Introduction






Criteria for the application of CCS

costshave to be reduced significantly

technologyis already available in principle, but has to be further developed for CO2 capture, transport and storage (mainly for very high mass flows)

ecology/risk assessmentevidence has to be mainly provided

for long-term secure storage

acceptancehas to be assured in

society (especially for long-term storage)

Potential future application of CCS in the cement industry

• Short-term: no relevance due to

- Very high costs (> 50 $/t CO2 avoided)

- Not existing availability of capture technologies

• Medium-term: depends on policy decisions and technical developments

- International climate policy

- Cost reductions due to technical developments (target value: 20-30 $/t CO2)

• Long-term: high relevance possible if

- Other options are exhausted

- Worldwide comparable costs for cement production would be introduced

Summary and outlook• CO2 capture technologies are not technically available for the cement

industry

• Pre-combustion technologies are not promising because only fuel CO2would be captured

• Oxy-fuel combustion is state-of-the-art in a few other industry sectors and seems to be promising for new kilns

• Post-combustion capture is state-of-the-art in other industrial sectors, but on relatively small scale

• From a today's point of view CCS is by far too expensive for the cement industry

• Huge research efforts would be/are necessary to develop CO2 capture technologies for the cement production process

• ECRA research project shall enable the cement industry to give scientifically based reliable answers to political requirements in the future

Documents

CO2 Capture and Storage: Options and Challenges for the ... · PDF fileChallenges for the Cement Industry ... preheater cooler The energy balance of a cement kiln will be ... 2 Capture