Thermo-Chemical Biomass Conversion for the Provision of Heat, Electricity and Fuels

Transcription

1 Thermo-Chemical Biomass Conversion for the Provision of Heat, Electricity and Fuels Univ. Prof. Dr. Hermann Hofbauer Vienna University of Technology, Austria

2 Outline of the Presentation Overview about thermal conversion routes Heat production Combined Heat and Power (CHP) production Bio-Fuel production Polygeneration

3 Bio-Fuel

4 Outline of the Presentation Overview about thermal conversion routes Heat production Combined Heat and Power (CHP) production Bio-Fuel production Polygeneration

5 Small Scale Heat Generation [energy from biomass] Trends in domestic heating: Advances in design Use of pellets increasing Low emissions of unburned Emission of aerosols is of major concern (health) In some areas emission of aerosols from biomass combustion equals the emission from traffic

6 District Heating and Systems in Industry Mostly grate fired systems Number rapidly growing Capacity up to ±20 MW th Fuels may be humid and varying particle size but not too much fines Fuels with low ash melting temperature are problematic High efficiencies (up to 90 %) with flue gas condensation even higher Emissions including fine dust emissions are low

7 Outline of the Presentation Overview about thermal conversion routes Heat production Combined Heat and Power (CHP) production Bio-Fuel production Polygeneration

8 Overview about the main possibilities for combined heat and power r (CHP) production from biomass Biomass Combustion Gasification Pyrolysis Hot flue gas, Steam, Heat carrier oil Low or medium calorific gas Liquid hydrocarbons Steam turbine / engine, ORC, Stirling engine Gas engine, Gas turbine Fuel cell Diesel engine, Gas turbine

9 CHP - Plants [energy from biomass] Combustion based systems Grate combustion with steam engine Organic Rankine Cycle (ORC-process) Grate combustion with stirling engine Fluidized bed combustion with steam turbine

10 State of the art of combustion based CHP Working medium Engine type Typical size Status Liquid and vapour (with phase change) Steam turbine Steam engine 500 kwe 500 MWe 100 kwe 1 MWe Proven technology Proven technology Screw type expander not established, similar size as steam engine Demonstration Steam turbine with organic medium (ORC) 500 kwe 1 MWe Some commercial biomass plants Gas (without phase change) Closed gas turbine (hot air turbine) Stirling engine not established, similar size as steam turbine 20 kwe 100 kwe Development Demonstration

11 CHP based on Biomass Gasification Heat Power Biomass Gasification Gas Cleaning Gas Utilization Air Steam Fixed Bed Fluidized Bed Particles Tar Gasmotor Gasturbine Brennstoffzelle Flue gas

12 CHP-Gasification [energy from biomass] Demonstration Plants Fixed bed gasification, Harbore, Dk Small scale (< 1 MWel) still in demonstration phase Medium and large scale (2-20 MWel) already commercial but only a few plants in operation Availability about % High fuel flexibility (kind of fuel, particle size, ash and water content) IGCC Varnamo,, SE Fluidized bed gasification, Güssing, AT

13 Biomass co-firing trends Co-firing Lahti, 60 MW, FI Co-firing is a key application (more than 10 plants in Europe) High efficiency (up to 40 % el.) Low investment costs High CO 2 avoidance per tonne of biomass Up to 10% on energy basis daily practice New PC units up to 30% of cofiring

14 Electr. efficiencies in % (Hu) Comparison of electrical efficiencies of different technologies Stirling engine SOFC+ Turbine SOFC MCFC Gas engine ORC Gas turbine IGCC Steam turbine Co-firing Power in kw

15 Electricity production costs Electricity production costs [ /MWh] Steam engine Fixed bed gasification ORC-Process Back pressure steam turbine Fuel power [MW th ] Fluidised bed gasification No investment subsidies 6 % p.a for 13 years Fuel costs: 14 /MWh Full load capacity heat: 4000 h Full load capacity electricity: 6000 h Incoming heat leads : 20 /MWh Market price

16 Outline of the Presentation Overview about thermal conversion routes Heat production Combined Heat and Power (CHP) production Bio-Fuel production Polygeneration

17 Bio-Fuel Production via Gasification Producer Gas (gas engine, gas turbine, fuel cell) Synthetic Natural Gas (BioSNG) Biomass Biomass Gasification FT-Fuels (FT-Diesel) Methanol Hydrogen others

18 Biomass to Liquid (BtL) [energy from biomass] example: Fischer-Tropsch WOOD SYNTHESIS GAS CARBON CHAIN FT-PRODUCT 2 CH 2 CH 2 (C 6 H 10 O 5 ) n CO + H 2 -CH H 2 O C n H 2n+2 Carbon (C) and hydrogen (H) bound in wood C- and H- building blocks Hydrocarbon monomer -CH 2 - Fischer-Tropsch hydrocarbons GASIFICATION SYNTHESIS

19 Güssing plant [energy from biomass] Biomass gasification State of the Art: BtL SNG-production CHOREN plant FT liquid fuel production Biomass Steam gasification: already demonstrated FT-synthesis: still a lot of research necessary First demonstration at CHOREN, Freiberg High bio-fuel yields (lit/ha) compared to first generation biofuel Costs depending on fuel cost and size of the plant (0,6-1,0 /litre)

20 Synthetic Natural Gas from Biomass (Bio-SNG) First Demonstration in the year 2008 at the Güssing plant: EU-Project BioSNG

21 Outline of the Presentation Overview about thermal conversion routes Heat production Combined Heat and Power (CHP) production Bio-Fuel production Polygeneration

22 Application of Producer Gas - Polygeneration Biomass Residues Heat and Power Feed Processing and Handling Gasification Gas Cleaning Heat and Power Generation Dedicated Crops Gas Conditioning Gas Cleaning Syngas Applications e.g. Hydrogen Bio-SNG FT-Liquids Methanol DME

23 % Efficiencies in Case of Polygeneration Synfuel Electricity District heat CHP-plants Fischer-Tropsch Bio-SNG Fuel orientation Fuel orientation Gas engine BIGCC FT FT POLY BioSNG BioSNG POLY

24 Bio-product/ market price Gap to market price Electricity Bio-SNG Bio-Methanol FT-Diesel

25 Provision of heat: CONCLUSIONS (1) By far the largest part of biomass utilization Technologies mature and commercialized (small scale as well as medium and larges scale) Pellets fired systems increasing rapily In modern systems emissions are low except Fine dust (aerosol) emissions are an important topic to solve

26 CONCLUSIONS (2) Provision of electricity: Mostly medium scale CHP plants with a great variety of power production technologies Combustion based systems Steam processes (turbine and engine) are commercialized since several decades ORC-process already successful demonstrated Stirling engine still under demonstration Gasification based systems Fixed bed gasifiers (small scale) still under development Fluidized bed gasifiers (medium and large scale) are already mature and commercially available Co-Firing in coal fired power stations Already demonstrated in a lot of plants ( MWfuel) High efficiencies and low production costs

27 Provision of bio-fuels: [energy from biomass] CONCLUSIONS (3) Biomass gasification is the key technology 2nd generation biofuels Taylor-made molecules with excellent combustion features (BtL (FT), BioSNG, DME) High yields per ha Technologies well known from coal but still under development for biomass research activities are still necessary Demonstration expected within the next two years Cost for large scale plants 0,5 0,6 /lit expected in long term Polygeneration can help to realize also medium scale plants reasonable production costs.