CMA

41 MSW. The waste is mostly converted into carbon dioxide and water; non-combustible materials (e.g. metals, glass, stones) remain as solid and ash residues. The actual plant design and configuration of incineration plant will differ considerably between technology providers. However, an Incinerator with energy recovery will typically comprise of waste reception and handling, combustion chamber, energy recovery plant, flue gas treatment and residual ash handling. Depending on how developed the waste management infrastructure and practices are, incineration of MSW is normally applied to untreated residual MSW (after mechanical biological treatment) and to almost raw MSW in some countries. Electricity generation from MSWI is only able to contribute with a small fraction of the electricity demand of the region where the waste is generated; efficiency is low, usually 15-25 per cent (best plants in the world achieves 30% efficiency). Combined heat and power incinerators utilize the excess heat for heating applications in addition to the electricity production. This way, the overall energy efficiency of the WtE plant can reach more than 80 per cent. Combined heat and power plants are common in Europe, but hardly used in developing countries. For utilization of excess heat, there must be a heating demand, which is often lower in countries with a warm climate. In Europe, WtE is considered a reliable method of treatment of waste for which there is no other alternative towards a circular economy. WtE plants in the EU are considered as ‘recovery’ options only when both electricity and heat are gainfully used. Success of WtE in Europe can majorly be attributed to the regulatory framework to avoid landfilling. WtE plants in Germany and Sweden, for example, receive largely segregated, high-calorific-value waste that is easy to manage. They have also installed highly sophisticated systems to further segregate waste so that a consistent quality of waste is fed to the plant. Waste receiving and storage Grate combustion and steam generator Flue gas treatment Energy from waste Consumables and residues 1. Unloading area 4. Feed hopper 7. Bottom ash discharger 13. Eletcrostatic Filter 18. Gas/gas heat exchanger 24. District heating system 27. Waste water treatment 2. Waster pit 5. Ram feeder 8. Primary air fan 14. Economiser precipitator 1 19. Flue gas reheater 2 25. Extraction condensation turbine 28. Waster water treatment 3. Waste crane 6. Reciprocating incineration grate 9. Primary air distribution 15. Quench 20. SCR- Catalyst 26. Hot water condenser 29. Ash conve ying 10. Secondary air fan 16. Wet scrubber (4 stops) 21. ID-Fan 30. Ash silo 11 . Flue gas recirculation 17. Flue gas reheater 1 22. Econmiser precipitator 2 12. 4-pass steam 23. Stack Figure 1. Overview of a MSWI plant (Hitachi Zosen INOVA).