Technology of the future for waste to energy plants

Transcription

1 Technology of the future for waste to energy plants Jeremy Crowley Kuala Lumpur,

2 Index Introduction to ESWET European Waste Legislation Technology for the future The combustion system and boiler The flue gas treatment system Conclusion 2

3 Introduction ESWET is the association grouping the European Suppliers of Waste to Energy Technology ESWET s Members supplied over 95% of the European Wasteto-Energy plants We represent the Members on a wide range of technical, communication and strategic issues, primarily towards the European Institutions, and also EU-level Stakeholders (other institutions, NGOs, industries, other lobbies) and the Interested General Public 3

4 Members 4

5 Improving waste management: EU Action Landfill Directive (1999) Decision to progressively move away from Disposal/Landfilling Waste Framework Directive (2008) 5-Step Waste Hierarchy Ambitious Recycling targets of 50% by 2020 Diverting useful material and energy from Landfill Need for reliable Waste-to-Energy technology 5

6 Improving waste management Environmental protection through sustainable waste management: Find the most efficient use for waste Waste-to-Energy = safety net for waste that is not suitable for recycling Source: European Commission 6

7 Energy Recovery Eco-Innovation: European leading technology Efficient and reliable thermal treatment Only the ultimate residues need disposal Material recovery: Clean Bottom Ash & Metals Environmental Benefit: Reduced strain on natural resources Waste-to-Energy is a necessary bridge between zero-landfilling and zero-waste 7

8 Waste Management 2010 Countries that recycle the most are also the ones relying on Waste-to- Energy for their residual waste, thereby minimising landfilling Eurostat data

9 Benefits: Waste A sustainable residual waste management solution Compared to Landfilling, Waste-to-Energy: Reduces waste volume by over 90% No effect on groundwater and soil Waste-to-Energy and downstream Material Recovery: Metals (ferrous, non-ferrous) can be recovered from the bottom ash (about 20 kg per tonne of waste in) Bottom ash can be re-used in e.g. road construction, saving natural resources (quarry-extracted mineral aggregates) and GHG emissions 9

10 Benefits: Air II. Protecting Air Quality Flue Gas Cleaning for the cleanest combustion technology Thanks to advanced Flue Gas Cleaning, emissions from Waste-to-Energy plants are negligible and meet the strictest Emission Limit Values of any combustion industry Waste-to-Energy sector s emissions are not an issue Waste-to-Energy (activity 5.(b) in EU IPPC classification) as a sector has disappeared from the Pollution Radar of top 10 significant industrial sectors on the E-PRTR (European Pollutant Release and Transfer Register) 10

11 Benefits: Energy Alternative source of energy for Heat & Electricity Base-load energy supply (not intermittent like wind or solar) Helps diversifying energy sources into electric and heat grids Local energy = reduces dependence on imported fuel supplies 11

12 Benefits: Climate Protection Waste-to-Energy and Climate Protection 1. Over 50% of municipal waste is biomass, a carbon-neutral energy source recognised as renewable 2. The energy recovered from waste offsets the use of fossil fuels and therefore their corresponding fossil carbon emissions are avoided 3. Avoids methane emissions that would have been generated by the same waste in landfills (Methane s Global Warming Potential is, in mass, 25 times that of CO 2 ) 12

13 Share of target (%) Benefits: Climate Protection Potential contribution from waste to energy plants to EU s target to reduce greenhouse gas emissions EU Target: To achieve at least 20% reduction of greenhouse gas emissions by 2020 compared to (Decision No 406/2009/EC) 15% is gained from avoiding landfilling % is gained from replacing fossil fuels 0 EU Target Potential contribution from waste to energy plants Source: PROFU 2009: What contribution can Waste-to-Energy make to the new EU targets for

14 BREF technology The European Union introduced the best available technology reference documents BREF in They describe the technology for waste incineration; the performance and emissions level EU has started an update of the incineration BREF - ready in 2016? The European solution to the next generation of Best Available Technology The revised BREF will set new and higher standards for Waste-to-Energy plants in terms of Higher efficiency Lower emissions New political tools = LCA (life cycle assessment) & R1 14

15 Energy Recovery Flue Gas Cleaning 15

16 The R1 Index or R1 Efficiency The EU Directive 2008 has introduced a new index aimed at qualifying the energy recovery from waste as a recovery process rather than as a disposal process Guidelines not that easy Not legal binding, but R1 > 0.65 Import of waste is allowed! Positive public image Planning permit Recovery process R1 > 0.65 New plants R1 > 0.60 Existing plants If not Disposal process 16

17 R1 as function of Gross electrical efficiency 17

18 Peterborough - 11 t/h 18

19 arc, Copenhagen 2 units total 1680 t/d High Steam Data + CHP 440 C and 67 bar η = 29% R1 =

20 Energy optimization Improvement of R1 Overall thermal plant efficiency Low flue gas outlet boiler temperature < 160 C (5-7 %) Low excess air, (O 2 % 5 %) (6-9 %) Reduce stack loss Reduce electrical own consumption Recover energy and preheat combustion air(1-2 %) Reduce loss of ignition, TOC < ½ % Maximum electrical output No pretreatment of waste = minimum own consumption Increase steam parameters (5-10 %) High performance steam turbines and condensers (10-20 %) Combined Heat & Power The proven solution 20

21 Combustion Grate 21

22 Water cooled Combustion Grate The overall object of the water cooled grate are to optimize the following goals: High thermal grate load Variation in fuel - heating value < 20 MJ/kg Operation at low excess air number Cooling of the combustion grate is independent of primary air Low NO x formation Cooling system integrated in shafts No problem with fusion of metal like classical forward/backward acting grates! No contact between the grate bars Reduces the mechanical forces during operation High availability & long operation Limits the wear-and-tear Combustion grate The Dynamic Movement of Combustion 23

23 Waste Feeding System and Grate 24

24 Boiler design Characteristics: CFD design Water cooled wear zone Inconel Boilers = improve heat transfer and corrosion protection Multi pass radiation part Flexible convection part Cleaning systems Online water shock cleaning Soot blowers Wrapping system Auto explosion 25

25 Boiler design Modern multi-pass boiler design: On-line Boiler Shock Washing System Advanced super heater configuration Superior combustion control system Basis for high steam data: 440 ºC / 70 bar High electrical efficiency 28 % 26

26 Corrosion in Waste Fired Boilers Corrosion caused by: Increasing: Steam temperature Flue gas temperature Particle impact High velocity Metal Temperature[ C] High Corrosio Fin centre tempe Low Corr Reduce corrosion by: Ceramic tiles New materials Inconel Co-flow super heaters CFD modeling Flue Gas Tempe 27

27 Energy recovery - Condensation Two stage recovery (in one or two scrubber sections): Direct condensation in scrubber Improved by heat pump Increased energy recovery by some % by condensation with heat pumps Cooling of the condenser District heating Process heat Total thermal efficiency > 95 % 28

28 Filborna Waste to Energy Plant in Sweden 27 t/h Heat storage Input 75 MW Output 60 MW District Heat 17 MW Electricity 29

29 Combination dry- and wet flue gas cleaning system 31

30 Conclusion Waste to Energy has a place in the waste management of the future Should be seen as a safety net after other options (reduction, reuse and recycling) have been utilised. Using the best available technology it is possible to Greatly improve the efficiency of the plant In a clean and proper manner 32

31 VIRTUAL PLANT TOUR Experience a guided virtual plant tour on our web site