Experiences: Preparation and Utilization of Solid Recovered Fuels (SRF) from commercial waste for heat production Reference Case: Flensburg Dipl.-Ing. Rüdiger Oetjen-Dehne Umwelt- und Energie Consult GmbH Gartenstr. 1 10115 Berlin Dipl.-Ing. Mathias Kalvelage MEISH GmbH Batteriestraße 48 24939 Flensburg 1
Introduction! Stadtwerke Flensburg operate three hard coal-fired fluidized bed boilers for long-distance heating production, which are renewed and extended for the Co-Combustion of Solid Recovered Fuels (Maximum: 8.75 t/h each boiler, depending on the SRF calorific value)! Additionally in the year 2006 together with 3 privatly owned waste-management companies a plant was realized to produce a furnace-finished, chlorine-depleted SRF from commercial waste.! The contribution describes the plant and the first operational experiences. 2
Treated Waste! Shredded Residues from a Sorting Plant (recovering Paper, Plastics and Metals) located near Hamburg: Fraction I: Size 15 to 50 mm (10/2006 3/2007) Fraction II: Size > 50 mm! Non shredded Residues from a Sorting Plant processing commercial and mixed construction waste.! Shredded Residues (e.g. plastics) from a Sorting Plant processing WEEE, different grain size range, > 20 mm. 3
Quality according to the permission- Examples - Elements Unit Value Ash-Content Ma.-% < 30 Chlorine-Content Ma.-% < 1 (X) Fluorine-Content Ma.-% < 0,08 Lower Calorific Value kj/kg > 11.000-24.000 Aluminium-Content Ma.-% < 1 Heavy Metals 80 % Perzentil MAXIMUM Lead mg/ kg Dry Matter 400 800 Cadmium mg/ kg Dry Matter 9 16 Chrome mg/ kg Dry Matter 250 750 Copper mg/ kg Dry Matter 750 1200 Mercury mg/ kg Dry Matter 1,2 4 SWF-Standard: Chlorine < 0,6 Ma.-%, Dry matter; Grain Size < 50 mm, can be pneumatically conveyed 4
Flow Chart 5
Storage and 1. Shredder 6
Primary Screen/Air Classifier 7
Sorting/2. Shredding 8
Short-Time Storage for SRF 9
First Operational Experiences: Composition of the Output Material EBS 73% Throughput: 20 t/h Maxium to produce good quality SRF Fe-Metalle 3% (Mechanical Throughput: 22 23 t/h) PVC 3% Schwerstoffe 6% Feinfraktion 14% NE-Metalle 1% 10
Lower Calorific Value depending on ash- and water-content 17.000 16.000 15.000 SRF from commercia l waste 14.000 Lower calorific value, kj/kg original SRF 13.000 12.000 11.000 10.000 9.000 8.000 SRF/RDF from houesehold waste WG = 15 % WG = 20 % WG = 25 % WG = 30 % WG = 35 % 7.000 WG = 40 % 6.000 WG = 45 % 5.000 15 20 25 30 35 40 45 50 Ashcontent, Ma.-% Dry Matter 11
First Operational Experiences: Degree of PVC- Separation 100 90 80 Degree of Separation PVC (%) 70 60 50 40 30 20 10 0 0,01 0,1 1 10 100 Articel Weight (g) 12
First Operational Experiences: Quality of SRF! the quality is altogether already very good! Chlorine: Medium 0,7 Ma.-% dry matter, n=23! Heavy Metals: mainly uncritically, some samples have too high Copper- and Antimony-Contents.! Grain-Size: 1 2 % > 50 mm, nearly 100 % < 80 mm! Ferrous- and Non-Ferrous Metal-Content < 0,01 Ma.-%, but there are some particles up to 200 mm " Therefore some optimization are tested or planned: " Reducing Chlorine-Content (e.g. by reducing the troughput or by changing the screening-efficiency) " Reducing long size metal components (e.g. by screening the SRF?) 13
First Operational Experiences! Co-Combustion started in Januar 2007 (at present 4 t/h) 14
Lessons learned Treatment of Commercial Waste to produce an furnacefinished solid recovered fuel is state of the Art. The chlorine-content of the raw material varies between 2 5 Ma.-%; therefore Near-infrared-Sorting is a must. The SRF have to be nearly metal-free. Multistage sorting is also a must. Co-Combustion of Solid Recovered Fuel in an fluidized bed boiler requires adjustments of the past control concepts. You need time and patience to implement the whole system successfully 15