Waste Management – Biological Treatment PDF 2024

Summer term 2024 — Waste Management – Biological Treatment Prof. Dr.-Ing. Matthias Franke Biological Waste Treatment Wastes suitable for biological treatment  Waste has to be (partially) biodegradable Waste  No inhibiting compounds (e...

Summer term 2024 — Waste Management – Biological Treatment Prof. Dr.-Ing. Matthias Franke Biological Waste Treatment Wastes suitable for biological treatment  Waste has to be (partially) biodegradable Waste  No inhibiting compounds (e.g. high heavy metal contents) Waste Waste from private Commercial waste from public areas households  Potential fractions, by origin: Household-like Yard waste Household waste commercial waste Production-specific Open market waste Organic waste industrial waste Sewage sludge Organic waste Sewage sludge Biological Waste Treatment Suitable waste types Dry organic Wet / liquid organic Mixed waste Biological Waste Treatment Recycling and contamination rate of food waste High Low  Globally approx. 30 % of food is lost at different stages Food producers Recycling rate of the food supply chain  Reduction of food losses and waste amounts are of high Food wholesalers priority in the waste hierarchy  Larger amounts of less-contaminated food waste can be Contamination rate collected at higher levels of the food chain Food retailers  Contaminations refer to waste unsuitable for biological treatment (e.g. plastics, metals, glas, etc.) Food-service-industry  Highest amounts of food waste, but most contaminated can be collected from households Households Low High Fig.: Recycling and contamination rate of food waste generated by actors along the food supply chain (FAO 2019) Biological Waste Treatment Principles, objectives and methods Principle of biological decomposition processes  Decomposition of available organic matter by the metabolism of microorganisms Objectives of biological processes  Reduction of the volume of the wastes  Winning of recyclables  Elimination of pollutants  Reduction of odor emissions Methods  Aerobic decomposition  Composting  Anaerobic decomposition  Fermentation Page 5 02.06.2024 © Fraunhofer Intern — Composting of biowaste Biological Waste Treatment Composting Page 7 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting Heat Easily soluble substances: Oxygen - carbohydrates New - amino acids organisms: Enzymatical degra- Bacteria, fungi, dable substances: protozoa Organic matter - hemicellulose + - cellulose Compost = - lipids, proteins Reconstructed Microorganisms organic Hardly degradable matter substances: - parts of cellulose - lignin Non-degradable Water substances: - minerals Water Carbon dioxide Page 8 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting Advantages  Recirculation of organic components, trace elements and fertilizing components into the loop  Comparatively little pollution  Relatively cheap Disadvantages  No energy production  Product is hard to sell (impurities, heavy metals,…) Structure  Nearly 600 large-scale plants for organic wastes  Decentralized composting in - agriculture - market gardens - households Page 9 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting Type and composition of the input material  Contained organic matter is only partly degradable: Waste categories Biodegradability Household waste [%] Carbohydrates Sugar, starch Very Good 11 Hemicellulose Very Good 63 Cellulose Good Lignin Difficult 19 Fats, oils, waxes Good 3 Proteins Mucins Very Good 4 Keratins Very Difficult Page 10 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – minerals, nutrients and milieu Necessity of mineral components  Nutrients (nitrogen, phosphorus, potassium)  Trace elements (Fe, Ni, Co, Mo, Se, …)  Alkaline buffers (neutralization of CO2 & organic acids)  Growth area for microorganisms Ratio of carbon and nitrogen: C/N ratio favorable to composting 35 : 1 (Start of composting) C/N ratios of wastes - Waste paper 300 : 1 - Kitchen waste 25 : 1 - Sewage sludge 15 : 1 - Wheat straw 128 : 1 - Saw dust 500 : 1 Optimal C/N ratio of the compost:15 – 20 : 1 - C/N < 15  nitrogen release into the soil  potential toxic for plants - C/N > 20  removal of nitrogen out of the soil Page 11 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – minerals, nutrients and milieu Microorganisms  Aerobic & facultative anaerobic bacteria  Actinomycetes  Mold fungi  Algae & protozoa Temperature ranges  Psychrophilic (bacteria, mold fungi): -4 - 30°C  Mesophilic (bacteria, actinomycetes) 10 - 45°C  Thermophilic (bacteria,  actinomycetes, mesophilic spores) 45 - 65°C (max. 75°C) Metabolism of microorganisms  20% of available energy is used for anabolism (growth)  80% of available energy is used for catabolism (energy production)  self-heating of the degrading material Page 12 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Degradation process Temperature phases Mesophilic phase (initial phase)  Accelerated reproduction of mesophilic microbes up to 45°C Thermophilic phase  Decrease of mesophilic microbes  Accelerated reproduction of thermophilic microbes between 45 and 55°C  By chemical processes self-heating up to 100°C possible  Heat damage of microbes possible  Errors in judging degree of composition Cooling phase  New increase in number of mesophilic microbes  Strong increase in actinomycetes Conclusion of the process  All easily decomposed substances are transformed, no more biological activity Page 13 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Degradation process Curve of typical pH-value and temperature Decomposition Reconstruction Building phase phase phase Decomposition 70 of polymers Decline 60 Decomposition 9 of monomers of fungi 50 8 Beginning Temperature nitrification 40 pH-value 7 30 6 Increase of small edaphic animals 20 Forming of 5 Mesophilic Thermophilic Cooling antibiotics Forming of 10 humic acids phase phase phase 0 Time Page 14 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Process requirements Water content  Necessary for metabolism of microorganisms (mass transfer through semi-permeable cell membranes)  Optimal water content about 55%  No biological processes at a moisture content < 20% Air pore volume  Optimum between 25 and 35% Oxygen requirements  Approx. 2 l air / g fresh material  Declining oxygen consumption in the course of the composting process  Highest oxygen consumption around 60°C Aeration by  forced aeration in closed degradation cells and aerated windrows  turning around of the windrows in static, non-aerated systems (windrows without turning not higher than 70 cm) Active surface area  A lot of surface area needed  Pretreatment (reduction of size) Page 15 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Waste pre-treatment Visual inspection in delivery area area  Preventing large waste components from entering processing equipment Screening  98% of all impurities in screening fraction > 60 mm  Utilization of round or flat screens Magnetic separation  Removal of ferrous component  Utilization of drum, overhead or roller magnets  Electric or permanent magnetic field Manual sorting  Done occasionally  Not recommended because of health hazards Size reduction (crushing)  Increasing of surface area of bio-waste  opening of material to microorganisms, improving of water absorption  Application of fast and slow mills and shredders Page 16 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Initial biodegradation processes Composting Batch / static techniques  In windrows, vessels or as briquettes in windrows (Brikollare process)  Advantages in breakdown frequency, cost, sanitization, compost quality and emission control static dynamic Dynamic  In degradation drums or towers  Better overall control  Faster processing natural forced aeration aeration Crushing & screening Curing  Mostly in windrows (triangular or trapezoid) Pressurized aeration aeration by suction Page 17 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Off-Gas Irrigation Aeration Fig: Static Box-/ Containercomposting Page 18 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Aeration Fig: Dynamic Tunnel composting Page 19 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Suction ventilation Fig: Dynamic Pile-composting Page 20 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Fig: Dynamic Drum-composting Page 21 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Composting – Technologies Brikollare Drum- Tunnel- Processes Composting Distribution of composting plant types in Germany Composting 1,2% 1% 5,9% Encapsulated Windrows 9,1% Box- and Container- Open and Composting roofed Piles 11,8% 66,7% Page 22 02.06.2024 © Fraunhofer Intern — Anerobic digestion of biowaste Biological Waste Treatment Digestion / Fermentation Page 24 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion Easily soluble substances: - carbohydrates Degestion residue - amino acids New Enzymatical degra- organisms: dable substances: Bacteria Microorganisms Organic matter - hemicellulose + - cellulose = - lipids, proteins Reconstructed organic Hardly degradable matter substances: - parts of cellulose Water Non-degradable Biogas substances: Methane - minerals carbon dioxide - lignin Page 25 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – anaerobic decomposition Particulate organic substrate Proteins Carbohydrates Fats 21 % 40 % 5% 34 % Hydrolysis Amino acids, sugar Fatty acids 46 % 20 % 34 % Acidogenesis Intermediates propionic acid, butyric acid Acetogenesis 35 % 12 % 23 % 11 % 8% 11 % Acetic acid ? Hydrogen Methanogenesis 70 % 30 % Methane Page 26 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – anaerobic decomposition Wet Fermentation Dry Fermentation (DM ≤ 15 %) (DM 25 - 50 %) Continuous Discontinuous Continuous Stirred digester Percolation digester Plug Flow digester Page 27 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – Dry fermentation Operator: Abfallwirtschaftsbetrieb München Capacity: 25.000 Mg/a Power: 570 kWel Treated Waste: Biowaste and Yard Waste Source: Bekon Energy Technologies GmbH & Co. Kg Page 28 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – Dry fermentation Gas production Continuous Biogas Production by time-delayed operation Retention time of discontinuously operated Batch Fermenters Page 29 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – Wet fermentation (Plant site Kirchstockach, Germany) Pulper Sandabscheider Biofilter Biowaste Fermenter Off-Gas Heat Screw-Mill Foreign CHP Electricity Bodies Dewatering Liquid Fertilizer Composting Processwater-Storage Page 30 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Digestion – Wet fermentation (Plant site Kirchstockach, Germany) Overview Delivery area and shredder Sand removal Digestate Composting of digestate CHP for biogas utilization Page 31 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Upgrading of composting plants by digestion A) Existing Pile-Composting CHP Plug-Flow Composting Fermenter B) Existing Box-Composting Percolate Composting Wet-Fermentation CHP Page 32 02.06.2024 © Fraunhofer Intern Biological Waste Treatment Co-digestion on-site a waste water treatment plant Rakings Sand-Trap Preliminary Nitrification/ Precipitation Final Clarification Denitrification Clarification Sewage Sludge Biomass Liquid phase Solid matter Heavy goods Biomasse- Shredder Pulper Separation of Centrifuge Composting Screen Slump Discharge heavy goods Page 33 02.06.2024 © Fraunhofer Intern — Mechanical biological waste treatment Mechanical biological waste treatment Suitable waste types  Household waste  Household-like ommercial waste (e.g. sludge from paper production)  Bulky waste  Sewage sludge  Street sweepings Page 35 02.06.2024 © Fraunhofer Mechanical biological waste treatment Overview Characteristics of MBT  Treatment of municipal solid waste (MSW) and comparable wastes  Processing steps: mechanical, biological and physical Objectives  Separation of materials  Production of substitute fuels  Stabilization  Reduction of the quantity of waste and of the contained carbon  Winning of recyclables  Elimination of pollutants Page 36 02.06.2024 © Fraunhofer Mechanical biological waste treatment Overview MT MBS (2,9%) Contribution of treatment facilities 25 (8,7%) to treatment of household waste in Germany (Source: BVSE) 20 MBT 15 (15,5%) Mg x 106 WIP 10 (69,7%) 5 2000 2006 2012 Mechanical Biological Capacities of thermal and Thermal mechanical-biological waste treatment in Germany (Source: BVSE) Page 37 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Plants for mechanical biological treatment Fraction with enriched Fraction with enriched calorific value for calorific value for energy recovery or energy recovery thermal treatment Mechanical Biological Mechanical processing treatment processing MP I BT MP II Recyclables Separated inert Separated inert Separated inert Biological for material materials for materials for materials for stabilized recovery landfilling landfilling landfilling fraction for landfilling Page 38 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Plants for mechanical biological stabilization Fraction with enriched Stabilized waste for calorific value for energy recovery energy recovery Mechanical Mechanical Biological Biological processing processing treatment drying MP I MP II BT Recyclables Recyclables Separated inert Biological for material for material materials for stabilized recovery recovery landfilling fraction for landfilling Page 39 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Plants for mechanical physical stabilization Stabilized waste for energy recovery Mechanical Mechanical Thermal processing processing drying MP I MP II Recyclables Separated inert Separated inert for material materials for materials for recovery landfilling landfilling Page 40 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Fraction with Large Fraction with high calorific Large components Thermal high calorific components Thermal Treatment value 14.000 Mg/a value 14.000 Mg/a Treatment 135.000 Mg/a 121.000 Mg/a 121.000 Mg/a 135.000 Mg/a Fine organic Intensive Household waste Fine organic Intensive Household waste Mechanical fraction to closed Covered Central landfill Bulky waste Mechanical fraction to closed Covered Central landfill Bulky waste waste Treatment biological Decomposition curing Cröbern Commercial Treatment biological Decomposition curing Cröbern Commercial waste treatment (Tunnel) 93.000 Mg/a 300.000 Mg/a treatment (Tunnel) 93.000 Mg/a 300.000 Mg/a 120.000 Mg/a 120.000 Mg/a Recyclables Recyclables Wood Material Inert materials Wood Material Inert Highmaterials ash components 15.000 Mg/a Recycling 15.000 High ash components MetalsMg/a Recycling 13.000 Mg/a Metals 13.000 Mg/a 17.000 Mg/a 17.000 Mg/a Page 41 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Unloading area and pre-shredding Page 42 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Drum-screens for pre-shredded waste Page 43 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Mechanical treatment Page 44 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Homogenization drum for organic biodegradable fraction (screen underflow) Automatic tunnel feeding device Page 45 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Examplary configuration and mass balance of a MBT plant in Germany / Cröbern Open roof curing of encapsulated biologically treated fraction Windrow turner Page 46 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Process steps and timeline of biological degradation at MBT plant Cröbern Intensive Biodegradation Curing Interim storage moving 8 weeks max. 2 weeks Tunnels 1 -22 Tunnels 23 -44 Organic residence time residence time 2,5 weeks 2,5 weeks Fine conditioning Landfill fraction residence time residence time Page 47 02.06.2024 © Fraunhofer Mechanical biological waste treatment Configuration of plants Produced refuse derived fuel at MBT plant Cröbern Page 48 02.06.2024 © Fraunhofer Mechanical biological waste treatment Comparison of output composition for different plant types 100 90 miscellaneous 80 Fe-Metals 70 NE-Metals 60 50 Foreign bodies 40 Low calorific fraction 30 Landfill 20 10 High Calorific fraction 0 MBT MBS MPS Page 49 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment Shredding Devices  Pre-Shredder → Slow Running  Fine-Shredder→ Fast Running Shredding Principles  Cutting  Tearing, Breaking ,Deforming, Crushing Shredding Types  Hammer Mills  Screw Mills  Cutting Mill  Ball Mill Page 50 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment – Shredding Hammer Mill 2-Shaft-Shredder Page 51 02.06.2024 © Fraunhofer Ball Mill Mechanical biological waste treatment Mechanical treatment – Shredding Mobile 2-shaft shredder Page 52 02.06.2024 © Fraunhofer Ball Mill Mechanical biological waste treatment Mechanical treatment – Shredding Screen basket Feeding Screen Shredding area Ball mill Page 53 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment - Screening Flip Flow Screen Drum Screen Disc Separator Page 54 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment – Air separation Air Classifier Photo: Air Classifier, Example Westeria Page 55 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment – Magnet separation Ferrous metal separator Combination of ferrous and non-ferrous metal separator Page 56 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment – optical sorting Example: TiTech PolySort-Process Material input Object identification Separation NIR-sensor Nozzle-control Conveyer belt positive fraction Acceleration belt Compressed air nozzles Conveyer belt negative fraction Page 57 02.06.2024 © Fraunhofer Mechanical biological waste treatment Mechanical treatment – Biological treatment Concepts for the biological process in MBT  Boxes Box, Windrow  Piles (14%) Percolation  Tunnels (8 %)  Percolation Wet Fermentation  Wet Fermentation (14 %)  Dry Fermentation Tunnel (42 %) Dry Fermentation (14 %) 56% aerobic 36% Combination aerobic/anaerobic Source: Ketelsen et al., 2006 Page 58 02.06.2024 © Fraunhofer Mechanical biological waste treatment Biological treatment Container-Rotting (aerobic) Location: Stralsund Capacity: 40.000 Mg/a Operator: Nehlsen AG Treated Wastes: Household Waste/Bulky Waste Page 59 02.06.2024 © Fraunhofer Source: Nehlsen AG Mechanical biological waste treatment Biological treatment Tunnel-Rotting (aerobic) Location: Rosenow Capacity: 125.000 Mg/a Operator: OVVD GmbH Wastes: Household Waste, Bulky Waste, Production Waste Page 60 02.06.2024 © Fraunhofer Source: Horstmann GmbH & Co. KG Mechanical biological waste treatment Biological treatment Wet fermentation (anaerobic) Photos: MBA Wiefels Page 61 02.06.2024 © Fraunhofer Mechanical biological waste treatment Biological treatment Percolation process (aerobic/anaerobic) Source: ISKA GmbH Page 62 02.06.2024 © Fraunhofer Mechanical biological waste treatment Exhaust air treatment Biological treatment in biofilters Page 63 02.06.2024 © Fraunhofer Mechanical biological waste treatment Exhaust air treatment Regenerative Thermal Oxidation – Two-Chamber-System 1 Exhaust air entry 2 Exhaust air-distribution 3 Steelvessel with isolation 4 Oxidation-zone 5 burner 6 Keramik heat exchanger 7 Clean gas fan 8 Clean gas exit Source: LTG GmbH Mechanical biological waste treatment Exhaust air treatment Regenerative Thermal Oxidation – Two-Chamber-System Problems with RTO-Two-Chamber- Systems:  Slipping of raw-gas during reversed flow direction  In- and Outlet-valves are open simultaneously for short time  Bypass-Flow of raw gas without contact to the RTO Zyklus 1 Zyklus 2 Mechanical biological waste treatment Exhaust air treatment Regenerative Thermal Oxidation – Three-Chamber-System Source: LTG GmbH Mechanical biological waste treatment Exhaust air treatment Regenerative Thermal Oxidation – Three-Chamber-System Short time purge operation Spülluft Spülluft Spülluft Zyklus 1 Zyklus 2 Zyklus 3 Normal operation Mechanical biological waste treatment Exhaust air treatment Acidic scrubbing Thank you very much for your kind attention — Prof. Dr.-Ing. Matthias Franke Director Fraunhofer UMSICHT Institute branch Sulzbach-Rosenberg Tel. +49 9661 8155-600 [email protected] Fraunhofer UMSICHT Sulzbach-Rosenberg An der Maxhütte 1 92237 Sulzbach-Rosenberg www.umsicht-suro.fraunhofer.de