Development of High Efficiency CFB Technology to Provide Flexible Air/Oxy Operation for Power Plant with CCS FLEXI BURN CFB

Transcription

1 Development of High Efficiency CFB Technology to Provide Flexible Air/Oxy Operation for Power Plant with CCS FLEXI BURN CFB 2 nd International Workshop on Oxyfuel FBC Technology Antti Tourunen VTT Technical Research Centre of Finland

2 Project objective Aim : to develop and demonstrate FLEXI BURN CFB concept enabling to reach the target of near zero emission power plants The FLEXI BURN CFB concept: High efficiency Circulating Fluidized Bed (CFB) power plant with CCS capable of air/oxy operation with a wide range of fuels including biomass The FLEXI BURN CFB concept has a set of important advantages: 1. fuel flexibility in order to decrease dependency on imported coals and in order to improve power plant economics especially with CCS operation 2. operational flexibility in order to apply air-firing and oxygen-firing with CO 2 capture 3. lower NO x production due to reduced and more uniform furnace temperature profiles, and lower SO x concentration in flue gases due to in-furnace capture, thus reducing the need for downstream flue gas cleaning 4. overall concept for phased transition into CCS technology with minimised risks through high efficiency air-oxy flexible CFB combustion 5. lower specific CO 2 emissions from the reduced consumption of fuel due to the intrinsic high efficiency of the technology. In addition, by substituting e.g. 20% of coal input with renewable fuels, CO 2 emissions can further be reduced by 15-20%. 6. Provides utilities an attractive alternative to take into use the new technology and decommission old capacity with lower efficiency and poorer emission performance 2

3 FLEXI BURN CFB diagram allowing operation under normal air-firing as well as oxygen-firing with CCS The FLEXI BURN CFB concept: High efficiency Circulating Fluidized Bed (CFB) power plant with CCS capable of air/oxy operation with a wide range of fuels including biomass Fuel Bituminous coal Lignite Biomass Pet coke etc. Large scale high efficiency CFB boiler with FLEXI BURN design Fluegas (CO 2 -rich) Flue gas cleaning Switch Stack CO 2 capture and storage (CCS) Condensation Compression Purification Transport Storage Air Switch Air Separation Unit (ASU) % O2 Mixing Flue gas recirculation

4 Role of FLEXI BURN CFB Partners Endesa, EDP, Tauron Generation UAP Utilities Development steps VTT, LUT, CzUT UNIZAR-LITEC, AICIA Research institutes Concept FWEOY, FWESA, ADEX, Siemens, Praxair Manufacturers Laboratory and small pilot scale test (0.1-1MW th ) FLEXI BURN CFB project Demonstration Pilot Plant 30 MW th, CIUDEN 1 st Commercial scale FLEXI BURN CFB Power Plant Industrial applicability

5 FLEXI BURN CFB - General project structure WP1 WP2 WP3 WP4 WP5 WP6 R&D support Design tools Demonstration Boiler design Power plant concept Commercial Scale FLEXIBURN Demonstration of FLEXI BURN CFB CIUDEN 30MW th - air-/ oxy-firing with fuel flexibility - CO 2 separation Field measurements at OTU CFB Lagisza 460 MWe - scale-up information from the world first and largest OTU CFB - design model validation Scale up criteria Commercial scale FLEXI BURN CFB Technology

6 Development and demonstration in multiple scales Bench scale Pilot scale Boiler scale BENCH SCALE REACTOR (BFB/CFB) Flue gas recirculation PILOT SCALE CFB COMBUSTOR FTIR sampling port Gas analysator Bag filter Gas cooling Deposit probe port AGISZA 460 MWe supercritical OTU CFB To Stack Cooler Filter Cyclone To stack Observation port Secondary cyclone Cooler/heater Fuel batch feed Zone4 Primary cyclone FTIR sampling port EXPERIMENTAL SCALES Secondary air Continuous fuel feed Fuel containers 1 and 2 Additive container Zone3 Zone 2 Zone1 Secondary gas O2, CO2, N2 M O2, CO2, CO, N2, SO2, NO Primary gas heating Air PC control and data logging system Primary gas heating Air PC control and data logging system 1D-MODEL flue gas to stack n n+1 MODELS AND DESIGN TOOLS Model analyses Volatile, moisture release CO combustion Mixing Char combustion n v b exp( A/ T)( d / d ref ) dy CO kef YCO d t k /(1/ ) ef 1 k CO m n-1 n-2 dm c rc kmc X dt n O2 Secondary air Primary air kw/m 2 kw /m 2 MODELS FOR PHENOMENA 1-D PROCESS MODELS 3-D PROCESS MODELS

7 Process scale-up Reference plant for the project Unit Capacity (MWe) 800 MWe 400 Lagisza 300 JEA 200 Turow 1 Tri-State Nova Scotia 100 Vaskiluodon Oriental Chem Pilot Plant General Motors Start-Up Year CFB technology is scaling up with the latest high-efficiency SC-OTU-references Lagisza (460 MWe). The Lagisza power plant (460 MWe), located in the southern Poland, is the world's largest CFB boiler, which is also the world's first supercritical CFB once-through unit (OTU) CFB800 agisza Turow 4-6 JEA Turow 1-3 Furnace - Width m Depth m Height m

8 Validation runs at a 460 MWe SC-OTU CFB boiler EMISSION ( at 6% O 2, dry flue gas) (follows EU s LCP directive), mg/nm 3 SO NO x (as NO 2 ) 200 CO 200 Dust Typical measurements during the test runs : Temperature profiles Pressure profiles Gas profiles Process data (including emission data) Fuel and ash samples 400 OTU SC CFB Boiler layout at Tauron Generation Lagisza Power Plant Concentration of SO 2 [mg/m 3 ] n (at O 2 = 6% in dry flue gases) SO 2 measuring data Concentration of NO x [mg/m 3 n ] (at O 2 = 6% in dry flue gases) NO x measuring data Temperature [ C] Measured calculated by model Concentration of CO [mg/m 3 n ] (at O 2 = 6% in dry flue gases) Unit load [MW e ] CO measuring data Concentration of dust [mg/m 2 n ] (at O 2 = 6% in dry flue gases) Unit load [MW e ] Dust measuring data Height [m] Unit load [MW e ] Unit load [MW e ]

9 BENCH SCALE REACTOR (BFB/CFB) FLEXI BURN CFB Demonstration steps CIUDEN 30MW Concept for 300 MW e Demonstration scales VTT 0.3kW BENCH SCALE REACTOR (BFB/CFB) VTT 0.1MW Flue gas recirculation To stack Bag filter PILOT SCALE CFB COMBUSTOR FTIR sampling port Gas analysator Gas c ooling Observation port Zone4 Zone3 Pr imary cyclone Depositprobe port FTIR sampling port Secondary cyclone S am pling por t CANMET 1MW Aim : to develop and demonstrate FLEXI BURN CFB concept enabling to reach the target of near zero emission power plants Cooler Cyclone Zone2 To Stack Filter Fuel batch feed Fuel containers 1 and 2 Additive c ontainer Zone1 Secondarygas O2, CO2, N2 Cooler/heater Secondary air Continuous fuel feed M PC control and data logging system Primary gas heating Air Completed PC control and data logging system O2, CO2, CO, N2, SO2, NO Primary gas heating A ir In progress 2009 Time 2012

10 Small pilot scale CFB experiments (0.1MW) under air- and oxygen-firing conditions Laboratory scale combustion tests have been carried out with pilot scale and bench scale test rigs at VTT Tests provide a base for development and validation of the design tools needed in the concept development Totally seven different fuels were selected for the combustion tests The selected project fuels cover the whole range of coals from anthracite to lignite Straw pellet represents a typical agrobiomass which is easily available whereas wood represents a typical good quality forest-based biomass which is also available in many locations of the Europe Fuels Mixture ratio on energy basis (LHV wet) Mixture ratio on mass basis (wet) Anthracite + Pet-coke 55/45 70/30 Anthracite Bituminous coal (Polish) Lignite (Spanish) + South African coal 55/45 70/30 Anthracite + wood 90/10 85/15 Bituminous coal (Polish) + straw pellet 80/20 75/25

11 Small pilot scale CFB experiments (0.1MW) under air- and oxygen-firing conditions Fuel reactivity Combustion process dynamics Transition between air- and oxygen-firing Air-firing Oxygen-firing Air-firing Oxygen-firing

12 Ash characteristics: air/oxy Oxygen-firing test with high temperature Bottom ash Air-firng (Test 19) CaCO3 [%] CaO [%] CaSO4 [%] Bottom ash Oxygen-firing (Test 20) CaCO3 [%] CaO [%] CaSO4 [%] Air-firing test Measured calcium compounds in bottom ash

13 Model based analysis of the CANMET test data Test program at CanmetENERGY, Ottawa 15 test weeks Runs: 88 of which 35 in air combustion 53 in oxy combustion Detailed analysis of solids mass balance Furnace vertical temperature profile Combustion and energy release profile Solids density profile Heat flux profile Furnace heat transfer Temperature High load OXY High load AIR Furnace height

14 Demonstration runs at a 30 MWth CFB pilot plant CIRCULATING FLUIDIZED BED BOILER FLOW DIAGRAM FLY ASH SILO LIMESTONE SILO AMMONIA, DeNOx FLY ASH FEEDING SYSTEM LIMESTONE, DeSOx BOILER FEED WATER FLUE GAS FLY ASH RECIRCULATION LIMESTONE SAND FUEL FEED SAND SILO FUEL SILO LIMESTONE FEEDING SYSTEM SAND FEEDING SYSTEM FLY ASH SYSTEM Presentation on Thursday 28 th June: Oxyfuel testing at 30MW th CIUDEN Oxy-CFB boiler MIXER MIXER FAN PRIMARY OXIDANT CB1 FUEL FEEDING SYSTEM MIXER FAN SECUNDARY OXIDANT CB2 NATURAL GAS START-UP BURNER SKID OXYGEN BOTTOM ASH

15 Specifications for a FLEXI BURN CFB demonstration plant Plant size: Two cases considered: Flexi Burn CFB demonstration plant: MWe gross. (Detailed technical scope, main focus) Full Commercial plant - post-2020: 800 MWe gross (techno-economical feasibility study)

16 Specifications for a FLEXI BURN CFB demonstration plant Steam parameters: Main steam temperature 598 ºC Main steam pressure 270 bar Reheated steam pressure 57 bar Reheated steam temperature 600 ºC Operating parameters: Dynamic requirements for the power plant Operational Mode Base Load Load change rate Max ramping 4%/min Minimum load 40% Start-up time (cold) <24h Start-up time (ASU cold) <8h Annual equivalent operating hours Oxy mode 6500 h CO 2 compressed to transport by pipeline H 2 O CONCENTRATION < 500 ppm CO < 2000 ppm O2 + N2 + Ar < 4 vol% SO x < 100 ppm NO x < 100 ppm CO 2 >95.5 % Other oxycombustion criteria: Air inleakage: Base case 1% (sensitivity analysis up to 3%) O 2 /CO 2 ratio: close to air concentration (24% O 2 wet) Oxygen purity: Oxygen purity 96,6 % vol Pressure 1,2 bar Temperature 20 ºC Air mode TOTAL 500 h 7000 h

17 Current status (1/2) A lot of experimental work has been carried out in order to support the development of FLEXI BURN CFB concept Combustion tests in different scales and field measurements in a commercial scale power plant provide a base for development and validation of the design tools needed in the concept development Demonstration tests at different scales: VTT 0.1MW, CANMET 1MW has been completed (totally over 100 oxyfuel test balances) with encouraging results Flexible operation under air- and oxygenfiring modes have been successful demonstrated in the small scales 0.1MW- 1MW Air Fuel Bituminous coal Lignite Biomass Pet coke etc. Switch Large scale high efficiency CFB boiler with FLEXI BURN design Fluegas (CO 2 -rich) Flue gas cleaning Switch Stack CO 2 capture and storage (CCS) Condensation Compression Purification Transport Storage Validation test campaigns with the world first and the largest (460 MWe) OTSC-CFB has been successfully completed Air Separation Unit (ASU) 95-97% O2 Mixing Flue gas recirculation

18 Current status (2/2) The design parameters for a FLEXI BURN CFB plant, from a technical and operational point of view, have been determined Two cases considered: 1) Flexi Burn CFB demonstration plant: MWe gross 2) Full Commercial plant - post-2020: 800 MWe gross The conceptual design of the FLEXI BURN CFB boiler has been developed The conceptual design for the FLEXI BURN has been implemented including a preliminary integration with the Air Separation Unit (ASU) and the Compression and Purification Unit (CPU) Oxidant Boiler Flue gas ASU CPU Integration Steam Integration Power Utilities Cycle Power Utilities

19 Next steps Demonstration tests at CIUDEN are ongoing Final verification of the concept based on the test results form CIUDEN Concept optimisation for the boiler island and the integrated power plant unit including dynamic simulation of the plant Health and safety assessment related to oxygen-firing conditions Estimate economics for the new concept and evaluate their feasibility on a commercial scale range Identification of the key success factors of the FLEXI BURN CFB technology covering the process efficiency, operability, maintainability, environmental impact and responsiveness to the market requirements, all leading to the economic performance of this new approach for power generation Project completed by February 2013

20 FLEXI BURN CFB More information on the project Acknowledgements: The research leading to these results has received funding from the European Community s Seventh Framework Programme (FP7/ ) under grant agreement n