CO 2 Capture and Storage: Options and Challenges for the Cement Industry

Transcription

1 CO 2 Capture and Storage: Options and Challenges for the Cement Industry Martin Schneider, Düsseldorf, Germany CSI Workshop Beijing, November 2008

2 CO 2 abatement costs will tremendously increase Global cost curve for greenhouse gas abatement measures beyond business as usual ; greenhouse gases measured in GtCO 2 e 1 Source: McKinsey-Quarterly 1/2007

3 CO 2 abatement costs will tremendously increase Global cost curve for greenhouse gas abatement measures beyond business as usual ; greenhouse gases measured in GtCO 2 e 1 1. GtCO 2e =Giga tonnes of CO 2 equivalent, business as usual based on emission growth driven mainly by increasing demand for energy 2. tco 2e = tonne of CO 2 equivalent 3. Measures costing more than 40$ were not the focus of this study 4. Atmosperic concentrations of all greenhouse gases recalculated into CO 2e in ppm 5. Marginal costs of avoiding 1tonne of CO 2e in each abatement scenarion Source: McKinsey-Quarterly 1/2007

4 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

5 CO 2 Emissions from Large Stationary Sources Process Power Plants Cement Production Refineries Iron and Steel Industry Petrochemical Industry Oil and Gas Processing Other Sources Emissions [Mt CO 2 /yr] * 10, *IPCC Special Report Carbon Dioxide Capture and Storage (2005)

6 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process - ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

7 The cement clinker burning process preheater exit gas kiln feed cooler exhaust gas fuel tertiary air secondary air primary air fuel cooling air clinker

8 CO 2 emissions from the clinker burning process Calcination of raw material: CaCO 3 CaO + CO 2 0,525 0,555 kg CO 2 /kg clinker Fuel combustion 0,280 0,415 kg CO 2 /kg clinker Electricity use Electricity use 6% Fuel combustion 38% Decarbonisation 56%

9 Options to control the CO 2 emissions from the clinker burning process Conventional technologies Reduction of clinker / cement ratio Decarbonated raw materials Utilization of biomass Limited reduction potential left Energy efficiency measures CO 2 capture technologies CO 2 capture at large stationary sources Transport of CO 2 to appropriate storage sites Not state of the art and very expensive Long-term underground storage of CO 2

10 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process - ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

11 General CO 2 capture technologies Pre-combustion capture Oxy-fuel combustion capture Post-combustion capture Others (e.g. carbonate looping,...)

12 Pre-combustion technologies (1) natural gas reforming process H 2 CO 2 combustion process storage coal biomass gasification process H 2 CO 2 combustion process storage

13 Pre-combustion technologies (2) Scheme of gasification process: Partial oxidation for heat supply CH 4 + ½ O 2 CO + H 2 Gasification of solid carbonaceous matter 2 C + O 2 2 CO C + H 2 O CO + H 2 CO shift for hydrogen synthesis CO + H 2 O CO 2 + H 2

14 Pre-combustion technologies (3) Level of implementation: Steam reforming is the predominant technology for H 2 production worldwide IGCC (Integrated Gasification Combined Cycle) demonstration plants since the 1970s IGCC can be realized with or without CO 2 capture Several full-scale IGCC projects with CO 2 capture are being planned in the power sector

15 Oxy-fuel combustion Elimination of nitrogen from the flue gas Combustion in pure oxygen or a mixture of oxygen and a CO 2 -rich recycled flue gas Flue gas consists mainly of CO 2 and water vapour Flue gas cooling to condense the water Concentrated CO 2 stream is compressed, dried and purified before delivery into a pipeline for storage

16 General scheme of Oxy-fuel combustion processes air air separation N 2 atmosphere exhaust gas recirculation fuel O 2 combustion process exhaust gas (CO 2 enriched)

17 Post-combustion technologies Flue gas from combustion processes is passed through equipment which separates most of the CO 2 Impurities in the flue gas stream are very important for the design of the plant and affect the costs significantly (low dust, NO 2 and SO 2 concentration required) End-of-pipe technology Commercially available (absorption technologies) Retrofit to existing plants possible

18 Different types of post-combustion technologies Absorption technologies: - Chemical absorption - Physical absorption Membrane processes Solid sorbent processes: - Physisorption processes - Mineral carbonation - Carbonate looping

19 Absorption technologies are most developed today Chemical absorption: - Amines (e.g. MEA) or inorganic salt solutions (e.g. K 2 CO 3 ) as absorbent - High energy demand for solvent regeneration - Very low dust, SO 2 and NO 2 concentration required -CO 2 capture costs for new coal-fired power plants: $/t CO 2 Physical absorption: - Solvents as absorbent (e.g. methanol) - High CO 2 content required CO 2 capture by chemical absorption (fertilizer plant in Malaysia)

20 Simplified flow sheet of chemical absorption process for CO 2 capture

21 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process - ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

22 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 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)

23 Assessment of CO 2 Capture Technologies Fuel generated CO 2 Raw material generated CO 2 Effects on burning process Applicable to the clinker burning process? Pre- Combustion yes no Oxy-fuel yes new plants Post- Combustion no new plants, retrofit

24 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 H 2 cannot be used in kiln firing H 2 flames have low heat transfer by radiation - temperature profile in the kiln - injection of raw meal or clinker dust

25 Applicability of pre-combustion technologies to the clinker burning process (2) Hydrogen from syngas of gasification processes as fuel for cement kiln burners? New combustion technologies required: - non-carbonaceous flame ingredients - new burner technologies for increasing heat transfer Only abatement of fuel CO 2 is captured 1/3 of total CO 2 emissions Hardly promising for clinker burning process

26 Applicability of pre-combustion technologies to the clinker burning process (3) air air separation N 2 atmosphere exhaust gas recirculation fuel raw material O 2 clinker burning process exhaust gas (CO 2 enriched) clinker

27 Applicability of pre-combustion technologies to the clinker burning process (4) 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

28 Influence of CO 2 partial pressure on decarbonation 1,0 kiln meal 2 degree of decarbonation pco2 = 0,2 bar 0,8 pco2 = 0,4 bar pco2 = 0,6 bar 0,6 pco2 = 0,8 bar pco2 = 0,97 bar 0,4 0,2 0, temperature [ C] The equilibrium temperature of the decarbonation of calcium carbonate and cement raw meals will be increased by K

29 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

30 The gas temperature profile in the rotary kiln will be changed by higher CO 2 concentration in combustion air temperature [ C] kiln length 0 Vol-% CO 2 10 Vol-% CO 2 20 Vol-% 30 Vol-% CO 2 40 Vol-% CO 2 50 Vol-% 60 Vol-% CO 2 reference 70 Vol-% CO 2 79 Vol-% CO 2 CO 2 CO 2

31 The maximum temperature of flame gases and raw meal in the sintering zone will be decreased by oxy-fuel operation temperature [ C] kiln feed gas C CO 2 concentration in tertiary-/secondary air" [Vol-%]

32 The energy balance of a cement kiln will be significantly affected by the oxy-fuel operation degree of efficiency [%] CO 2 concentration in combustion air [Vol-%] degree of efficiency [%] preheater cooler

33 Applicability of post-combustion capture to the clinker burning process CO 2 transport, storage air fuel raw material clinker burning process CO 2 absorption exhaust gas (CO 2 poor) clinker

34 Application of CO 2 capture with amine absorption in a Norwegian 3000 t/d cement plant (pilot study) Technical requirements: NO x abatement with SNCR SO 2 abatement with wet scrubber waste heat recovery boiler CO 2 capture amine absorption Amine recovery with stripper Gas fired boiler 2006 data 110 Investment costs in mio thereof: - waste gas cleaning - waste heat recovery boiler -CO 2 capture -CO 2 drying and compression - boiler Operating costs in mio /year 32 Total costs in /t CO

35 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

36 CCS: CO 2 capture, transport and storage

37 Transport of CO 2 is state of the art but for considerably smaller quantities CO 2 transport ship CO 2 pipeline

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

39 Storage Options for CO 2 CO 2 enhanced oil recovery CO 2 enhanced gas recovery CO 2 enhanced coal-bed methane recovery (ECBM) Storage in depleted oil and gas fields Storage in deep saline aquifers Other storage options

40 Storage Options for CO2

41 CO 2 storage with enhanced oil recovery (EOR) CO 2 injection recycled CO 2 production well CO 2 water oil Source: IEA 2004

42 International CO 2 Storage projects

43 Exhaust gas composition effect on CCS Impurities SO 2 NO x H 2 S H 2 O Known effects on density of compressed CO 2 compressibility water solubility flow rate No significant difference between CO 2 from cement plants and power plants Small impact of efficiency

44 Criteria for storage site selection Trapping mechanisms: Physical: statigraphic and structual Physical: hydrodynamic Geochemical Others Source: Baele, J.-M., 2008

45 Suitable storage formation - Belgium, an example Campine Basin: Potential sequestration in coal seams Subsequent coal bed methane production Source: P.C.H., 2001

46 CO 2 Capture and Storage: Options and Challenges for the Cement Industry 1. Introduction 2. The cement clinker burning process 3. General CO 2 capture technologies 4. Applicability of CO 2 capture technologies to the clinker burning process - ECRA research project 5. CO 2 transport and storage 6. Summary and outlook

47 Criteria for the application of CCS ecology/risk assessment evidence has to be mainly provided for long-term secure storage technology is already available in principle, but has to be further developed for CO 2 capture, transport and storage (mainly for very high mass flows) acceptance has to be assured in society (especially for long-term storage) costs have to be reduced significantly

48 Potential future application of CCS in the cement industry Short-term: no relevance due to - Very high costs (> 50 $/t CO 2 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: $/t CO 2 ) Long-term: high relevance possible if - Other options are exhausted - Worldwide comparable costs for cement production would be introduced

49 Summary and outlook CO 2 capture technologies are not technically available for the cement industry Pre-combustion technologies are not promising because only fuel CO 2 would 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 CO 2 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