The Role of Solid Fuel Conversion in Future Power Generation

Transcription

1 The Role of Solid Fuel Conversion in Future Power Generation Hartmut Spliethoff FINNISH-SWEDISH FLAME DAYS 2013 Focus on Combustion and Gasification Research Jyväskylä, April, 17th and 18th 2013

2 Content 1. Future Developments 1. Worldwide 2. Germany 2. Power Station Requirements 3. Technologies - What Power Plants are required? 4. Research Demand for Solid Fuels 5. IFRF Research 6. EF Gasification Research at TUM

3 1. Future Primary Energy World, New Policies Scenario IEA, WEO 2011

4 1. Future Importance of Coal Worlwide IEA, WEO 2012

5 1. Future Importance of Biomass Worlwide IEA, WEO 2012

6 1. Future Energy concept 2010 (Germany) Power Generation

7 2. Requirements Power requirements Situation Germany 2010 Today (2010): Share of renewables 16 %, Wind 26 GW, PV 17 GW Source: Spliethoff: et. al, CIT 2011

8 2. Requirements Power Requirements Germany : Wind 46 GW, PV 50 GW, Constant consumption Requirement for low minimum load Source: Spliethoff: et. al, CIT 2011

9 2. Requirements Power Station Requirements Efficiency Investment costs Flexibility Future: Operational hours Investment costs Flexibility: Start-up time, minimal load Load change capability Efficiency??

10 3. Technologies Technologies for the future - Storage technologies: - Long term: chemical storage - Power to heat - Flexible conventional power generation for balancing - Combined Cycle the preferred technologies - Pulverized Coal Power Station with low investment costs - Integration of storage technologies - Renewables: - Biomass - Waste Source: Spliethoff: et. al, CIT 2011

11 3. Technologies Comparison Flexibility: CC versus PC Combined Cycle (new) Pulverized Coal Power Station new old Load Change 3-6 % / min 3-6 % / min 2-4 % / min Minimum load 25 % (2 GT) 20 % 40 % Start-up hot (8h) warm (48 h) 0,5 1 h h 1-2 h 3 h 2 h 4-5 h Source: Spliethoff: et. al, CIT 2011

12 3. Technologies Ongoing developments - PC Reduction minimum load Firing stability determines minimum load: Requirement: safe operation in case of a mill failure Bituminous coal: Reduction for pure coal firing: % 20 % Brown coal: Reduction from appr. 50 % to 20 % by predrying Operation without power production Source: Spliethoff: et. al, CIT 2011

13 3. Technologies Gasification - challenges and opportunities Technische Universität München + High efficiency - Costly - Low availability Gasification Power Production (IGCC) Flexibility in the context of increasing renewables Efficient CO 2 - separation Chemicals and energy carriers/ polygeneration

14 3. Technologies Gasification - challenges and opportunities Technische Universität München Electrolysis Gasifier Storage for SNG and FT fuels infrastructures are already present Chemical Synthesis Methanol SNG FT liquids 19

15 3. Technologies IGCC-EPI: Excess Power Integration Coal 100% Entrained flow gasifier Quench/ HRSG H 2 S Rectisol 0-100% El. Energy Gasturbine Exhaust gas HRSG El. Energy Steam turbine cycle O % 0-100% Synthesis El. Energy ASU % 0-100% O 2 H 2 O 2 -storage Electrolysis Excess power H 2 -storage H 2 SNG Gas grid

16 3. Technologies Waste Zella Mehlis, Germany Electrical Efficiency - Europe, average: 13 % - new conventional plants: 18 %

17 3. Technologies Biomass Entrained Flow gasification Biomass C x H y O z Source: hs energieanlagen gmbh Source: Fluidized bed gasification Gas cleaning, tar, sulphur, Methanation SNG 23

18 4. Research Demand Conversion H 2 O Volatiles Volatiles combustion CO 2, H 2 O Raw coal Heating/ drying Pyrolysis Char combustion Ash Step Demand Examples Pyrolysis 2 Kinetics, composition, impact on char structure Volatile comb. 3 Gas phase combustion Char combustion 1 Kinetics for O2, CO2, H2O, char structure and reactivity

19 4. Research Demand Emission Example NOx emission N 2 Volatiles Volatil N NO raw coal N Fuel nitrogen char fixed N coal char N 2 - Demand: extensive research in the past and secondary measures lower research demand - Key: Distribution volatile N and char-n

20 4. Research Demand Ash related issues - Ash makes the difference to gas combustion - Operational problems such as slagging, fouling and corrosion are domnination design and operation - Research demand: - Ash formation - Ash chemistry -.. Mineral inclusions coal particle ash particle Evaporation Tail coke particle anorganic vapours Nucleation fragmentation heterogeneous condensation char combustion Coagulation I superfine particle (0,1 µm) II agglomerated ash particle (0,1-10 µm) III flyash (1-20 µm)

21 Membrane reactor Conventional Technische Universität München 4. Research Demand Gasification Gasification is an old technology knowledge base is low CCS power plant today is based on available technologies Gasifier Gas cleaning High T shift Low T shift CO 2 separation Coal H 2 CO 2 - with CCS η < 40 % - without CCS η 50% Gasification offers a high potential (integration, membranes) Gasifier Gas cleaning Membrane shift Coal H 2 CO 2 KEY for future development: Knowledge of coal behaviour including mineral matter/ trace components at highest temp./ pressures and reducing conditions

22 4. Research Demand Fuel characterization and CFD-modelling Technische Universität München Requirement for design and operation: to know the impact of - fuel quality and - combustion conditions on - Combustion behaviour, - Emissions - Slagging, fouling and corrosion Approach: Fuel Characterization: Advanced FC, which consider large scale combustion conditions CFD modelling: data of fuels and ashes required

23 5. IFRF Research IFRF - Fuel characterization Characterise solid fuels to fill data gaps for numerical model validation & application includes fuels that are environmentally and economically significant Biomass, Wastes, Blends with coals In atmospheres that reflect O2/RFG approach, temperatures and pressures of current interest to members and other sponsors (steam, CO2) Establish protocols for solid fuels combustion/gasification characterisation Produce and maintain DATABASES (IFRF Solid Fuel Database-

24 5. IFRF Research The IFRF Isothermal Plug Flow Reactor (Livorno Italy) Length 4 m, ID 0.15 m 8 modules, 19 feed ports quenched collector probe 60 kw burner, 54 kw resistances C ms residence time carrier gas (O2, N2, CO2 mix) conditions similar to those of full scale plants

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26 5. IFRF Research IPFR Qualification: CFD modeling Issues: Temperature is really isothermal? Particles residence time distribution trajectories Partciles actual T vs time history CFD modeling can help to correctly analyze and interpretate the raw data produced by IPFR.

27 5. IFRF Research Materials Straw pellets (Denmark) Torrefied Spruce (BE 2020) Sofwood pellets (BE 2020) DDGS (TUD) Palm Kernel Shell (+ torrified) (KTH & Poland) Lignine (Italy) Sunflower seeds (Italy)

28 5. IFRF Research IPFR - Conversion versus time/ T, gas composition experimental data with error bars and sub-model fitting

29 6. Gasification Research at TUM Research Project - Industry Partner: Siemens, Air Liquide, RWE, EnBW, Vattenfall Research Partner: TUM, TUB Freiberg, FZ Jülich, GTT CFD Simulations Gasification Kinetics IGCC Concepts In-situ Monitoring Trace Species Condensation

30 6. Gasification Research at TUM Coal Gasification Kinetics Technische Universität München

31 6. Gasification Research at TUM Experimental Procedure Technische Universität München

32 6. Gasification Research at TUM Pressurized High Temperature EF Reactor (PiTER) Experiments at pressure 7 m Gasification in CO 2 /H 2 O/O 2 Pyrolysis in inert atmospheres Char and gas analysis 1 m Technical Data Temperature: up to 1800 C Pressure: up to 5.0 MPa Residence time: s Feed: pulverized coal Fuel mass flow: up to 5 kg/h Gas vol. flow: max. 100 m N ³/h Gas composition: N 2,H 2 O,CO 2,H 2, O 2,CO Reactor height: 7000 mm Reaction tube length: 2200 mm inner diameter: 70 mm

33 Temperature [ C] Technische Universität München 6. Gasification Research at TUM Experimental facilities Babiter, WMR and PTGA PWMR (a) PTGA (b) (c) 1100 C, 5.0 MPa 1600 C, 5.0 MPa BabiTER 1600 C, atmospheric Sample Gas preheater Coal feeder MPa 1.0 MPa Pressurized heating system Heating zones MPa 5.0 MPa Time [s] Optical ports Balance system Water quench Sampling probe Gas analysis Char filter

34 6. Gasification Research at TUM Reaction kinetics in a technical EF Gasifier

35 Conclusions Relative decrease of coal utilization in the medium and long-term, but absolute increase in the short and medium term Importance of biomass and waste fuels Increase of fluctuating renewables requires flexible power plants Research in solid fuels is still required