Carbon (CO 2 ) Capture

Transcription

1 Carbon (CO 2 ) Capture Kelly Thambimuthu, Chief Executive Officer, Centre for Low Emission Technology, Queensland, Australia. & Chairman, International Energy Agency Greenhouse Gas Program (IEA GHG) CSLF Workshop, Salvador, Bahia, Brazil, 8 September 2008 kelly.thambimuthu@csiro.au

2 Outline of the Presentation What is CCS A carbon (CO 2 ) capture primer Where to capture CO 2 Why capture CO 2 Options for CO2 capture Other low emission, utilisation and environmental targets Cost of CCS and technology development for cost reduction CCS - a bridge to a sustainable energy future

3 . What is carbon (CO 2 ) capture and storage (CCS).

4 CO 2 capture and storage (CCS) Requires economy of scale to achieve low costs

5 . A carbon (CO 2 ) capture primer.

6 Where to capture (or decarbonise energy) million tonnes of CO Power Generation Other Transform ation Industry Transport Other Sectors Significant emissions growth in power generation and transport - large power generation and industrial plants represent over 60% anticipated of 2030 emissions IEA WEO 2004

7 Why capture CO 2 Relative volumes at storage pressure Pure CO % CO 2 Coal fired power plant flue gas Storage pressure: 100 bar 3-5% CO 2 Natural gas combined cycle plant flue gas Saves pore space and compression energy

8 CO 2 capture stream concentrations Coal boiler Gas boiler Gas CCGT Blast furnace Cement (low) Cement (high) Refinery heater Capture penalty higher at lower concentration

9 Options for CO 2 capture Schemes also applicable to gas and oil

10 The capture technology tool box Post-combustion Precombustion Oxyfuel Separation task CO 2 / N 2 CO 2 / H 2 O 2 / N 2 Currently preferred (available) technology Chemical solvent scrubbing Physical solvent scrubbing, adsorption and polymeric membranes Cryogenic separation Other enabling technologies are also required

11 Post-combustion capture Air Power generation Addition of SCR for denox in some cases Capture N 2, O 2, H 2 O to atmosphere Fuel Boiler or gas turbine (FGD-not for NGCC) Solvent scrubbing Steam Steam turbine Power CO 2 compression CO 2 to storage

12 Liquid solvent scrubbing Absorber Reduced-CO 2 flue gas CO 2 -lean solvent Stripper CO 2 Condenser Flue gas CO 2 -rich solvent Steam Reboiler

13 Liquid solvent scrubbing (2) Widely used for reducing gases, e.g. natural gas Less widely used for oxidising flue gases e.g. coal MEA 1 used in post-combustion capture plants CO 2 is used mainly for chemicals and food and drink New solvents being developed and used e.g. hindered amines Lower energy consumption, solvent losses, corrosion Low SO X (<10 ppm) and NO 2 (<20ppm) is needed Possible with limestone-gypsum FGD and SCR 1. MEA: mono-ethanolamine

14 Post-combustion CO 2 capture with MEA Warrior Run power plant, USA 180 MW e coal fired circulating fluidised bed combustor 150 t/d of CO 2 captured from a slipstream About 5% of the total

15 Post-combustion CO 2 capture MHI solvent Fertiliser plant in Malaysia CO 2 recovery from a natural gas derived flue gas 200 t/d of CO 2 captured First generation of new KS1 solvent Operating since 1999 Capacity equivalent to flue gas from a 10 MWth coalfired plant

16 Post-combustion capture Advantages Existing combustion technology can be used Retrofit to existing plants is possible But retrofit to old inefficient plants is not attractive Experience in small power plants, scale-up key issue Disadvantages Energy penalty has been relatively high Penalty is being reduced by process & heat integration Solvents are degraded by oxygen and impurities Need to dispose of degraded solvent Water use can be high

17 Oxy-combustion Air Air separation Oxygen Recycled flue gas Vent Fuel Boiler or gas turbine Steam Cooling (optional FGD) Purification/ compression CO 2 Steam turbine Power 20% of normal exit gas flow in boilers

18 Oxy-combustion Advantages Combustors could be fairly conventional Possibility of compact boilers with lower gas recycle Possibility of avoiding FGD (& denox unit) Disadvantages Only tested at a small scale High cost of oxygen production Advanced oxygen separation membranes with lower energy consumption are at pilot plant scale New gas turbines designs are needed Will only be developed if there is a large market

19 Oxy-combustion boiler demonstration Vartenfall, Germany 30MWth

20 Oxy-steam combustion pilot plant 5 MW e CES water cycle plant at Kimberlina, California

21 Pre-combustion capture natural gas Natural gas fired plant CO 2 compression CO 2 Natural gas Partial Oxidation CO+H 2 O H 2 +CO 2 Shift conversion Acid gas removal Air Or steam reforming Combined cycle Fuel gas (mainly H 2 ) Power

22 Pre-combustion capture - coal IGCC with CO 2 capture Coal Steam Gasification Oxygen CO+H 2 O H 2 +CO 2 Shift conversion CO 2 compression Acid gas removal H 2 S Fuel gas (mainly H 2 ) CO 2 Sulphur Sulphur recovery Air Air separation Nitrogen Combined cycle Power Air Air

23 Coal IGCC without CO 2 capture 4 coal-based IGCC demonstration plants in the USA, Netherlands and Spain Availability has been poor but is improving IGCC is not at present the preferred technology for new coal-fired power plants Main commercial interest in IGCC is currently for use of petroleum residues Several plants built and planned at refineries

24 Coal IGCC without CO 2 capture Shell gasifier IGCC plant, Buggenum, Netherlands

25 Coal gasification with CO 2 capture Dakota Gasification Plant, USA Synthetic natural gas production from lignite CO 2 used for EOR at Weyburn, Canada CO 2 contains about 1% H 2 S

26 CO 2 capture in IGCC Advantages of IGCC for CO 2 capture High CO 2 concentration and high overall pressure Lower energy use for CO 2 separation and compact equipment Proven CO 2 separation technology can be used Possibility of co-production of hydrogen Disadvantages IGCC is unfamiliar technology for power generators Existing coal fired IGCC plants have low availability Hydrogen burning turbines yet to be developed IGCC without CO 2 capture has generally higher costs than pulverised coal combustion

27 CO 2 and other near zero emission targets for power plants Technology SO2 NOx as NO2 Particles Mercury CO2 mg/m³ mg/m³ mg/m³ kg/kwh Pulverised Coal +FGD & SCR (to 98% removal) (SCR) IGCC (Coal) 98-99% removal <125 <1 Natural Gas Combined.Cycle (as low emission NGCC) negligible < (lower targets with CO 2 capture) (85-95% removal) Low Emission Pulverised Coal <100 (lower targets with CO 2 capture) <125 (lower targets with CO 2 capture) <10 90% Removal 85-95% Removal Low Emission IGCC 99% Removal <1 95% Removal 85-95% Removal Source: IEA Clean Coal Centre

28 Other utilisation & environmental targets All wastes go to places where their effects are considered benign e.g. Sequestered CO2 Landfill for ash/slag Clean water Where possible waste products are found a useful purpose elsewhere or are recycled e.g. Building materials Enhanced oil or coal seam methane recovery Process, irrigation or potable water The aim is to develop cleaner as opposed to clean-up technologies

29 The cost of CCS.

30 Power generation efficiency Efficiency, % LHV Postcomb IGCC slurry IGCC dry Oxyfuel Postcomb Oxyfuel Coal Natural gas Without capture With capture Source: IEA GHG studies

31 Efficiency decrease due to capture Percentage points CO2 compression and purification O2 production and power cycle impacts Shift conversion and related impacts Power for CO2 separation Steam for CO2 separation 0 IGCC slurry Coal IGCC dry Oxyfuel Postcomb Postcomb Oxyfuel Natural gas Source: IEA GHG studies

32 Increase in electricity costs Increase in costs due to capture, % Postcomb IGCC slurry Coal IGCC dry Oxyfuel Postcomb Fuel Capital Electricity Oxyfuel Natural gas Assumptions: 10% DCF, Coal $1.5/GJ, Gas $3/GJ; Relative to same base plant without capture Source: IEA GHG studies pre 2004

33 Options for application of CO 2 capture Retrofit equipment for CO2 capture in existing plants drawbacks include site limitations, poor system integration and significantly reduced energy efficiency Replace all equipment at a given site to upgrade process efficiency and with process integrated capture plant benefit of high efficiency base equipment with lower energy penalties and costs for capture. Also reduces other environmental emissions New build capture ready or capture plants the former providing opportunities for conversion at a later date

34 Improvements to CO 2 capture and enabling technologies.

35 Improvements to the capture technology tool box Post-combustion Precombustion Oxyfuel Separation task CO 2 / N 2 CO 2 / H 2 O 2 / N 2 Currently preferred (available) technology Chemical solvent scrubbing Physical solvent scrubbing, adsorption and polymeric membranes Cryogenic separation Advanced technologies Improved scrubbers Improved scrubbers Oxygen membranes Membranes Membranes Chemical looping Solid adsorbents Requires more energy efficient CO 2 capture

36 Efficiency trends in power plants target PC >2020 target Fuel Cell/Gasification Carnot Efficiency [%] target!gcc Temperature [Degrees Celcius] Steam cycle + denox and FGD PFBC IGCC NGCC Source: IEA In fact in need of both energy efficient CO 2 capture and higher power efficiencies

37 Path to improved low emission coal-fired, IGCC Now Increasing efficiency, lower emissions, lower costs 2020 onwards Commercial non-co 2 Capture IGCC plants IGCC commercial scale demos ~38-44 %LHV Dry cleaning options: Particulates, Sulphur, Nitrogen, trace elements NOx activities: reduce emissions Early full scale IGCC with CO 2 capture ~32-35 %LHV Hydrogen Turbines CO 2 capture activities: physical scrubbing demo CO 2 capture activities: Gas separation & reactor membranes New Oxygen production plants commercial Advanced IGCC low emission plants various technologies multi-products ~42-44 %LHV Beyond 2020; stationary fuel cells (IGFC) %LHV? An example of technology improvements that can increase energy efficiency and reduce costs by at least 20-30%

38 Example of new technology deployment, IGCC Research Development Demonstration Deployment Mature Technology CO 2 Capture Anticipated Cost of Full-Scale Application CO 2 Storage 1 st Generation IGCC with CCS IGCC Power Plants Elements currently commercial in the petrochemicals sector Expected availability can increase with time and learning by doing Time

39 . CCS as a bridge to sustainable energy futures.

40 Towards a vision of a de-carbonized H 2 & electricity economy or Coal Coal With CO 2 capture & storage, will this be a bridge to our energy future? Source: Adapted from Olav Karstaad, Statoil

41 Electricity energy carrier Coal (100) (33-42) Natural gas Electricity Renewables and gas Transport CO 2 capture for coal X X CO 2 storage Industry Residential

42 Sources of global electricity production 40% in 2007 Hydro & Renewables 24% Coal 31% Nuclear 10% Oil 12% NG 24% Total global production ~3500 GWe Source: 2002/3

43 Hydrogen energy carrier (100) (60-73) (24-44) Coal / gas Hydrogen Renewables CO 2 capture for coal and gas Transport CO 2 storage Industry Residential

44 Sources of global hydrogen production Coal 18% Electrolysis 4% NG 48% Oil 30% Total global production 50 Mt/y of H 2 ~5% of electricity generation Source: 2004 statistics

45 The future for low emissions plants with CCS Coal or Natural gas Centralised power and industrial plants Combustion Gasification or Reforming Distributed energy & products Chemical products Industrial products CO 2 to storage CO 2 capture Chemicals Hydrogen Liquid Fuels Power Generation Distributed heat & power Transport vehicles Heating or cooling Electricity

46 Some key messages CO 2 can be captured at large point sources in power generation and other major industries Capture can contribute to emission reductions in other sectors by use of decarbonised electricity and hydrogen energy carriers produced in centralised plant Technologies for CO 2 capture, transport and storage are currently available, power plant capture needs to be demonstrated on a larger scale In power generation CO 2 capture accounts for up to 2/3 of the cost for capture, transport and storage -increases electricity cost by 20-50% CO 2 needs to be captured more widely to increase confidence and reduce costs Energy penalties (6-11 percentage points) and costs are substantial but can be reduced by technological developments Prudent policy measures need to be implemented now to encourage R&D, early deployment and commercialisation of advanced technologies

47 clet s Partners and Mission The State of Queensland through the Department of Mines and Energy Australian Coal Association Research Limited Stanwell Corporation Limited CSIRO through CSIRO Energy Technology and its Energy Transformed Flagship Program Tarong Energy Corporation Limited The University of Queensland.progressing the development of enabling technologies for the low emission production of electricity and hydrogen from coal.

48 IEA Greenhouse Program IEA GHG