Use of MSWI by-products H.J.H. Brouwers M.V.A. Florea P. Tang K. Schollbach Q. Alam V. Caprai
Dutch waste situation/policies Landfill ban on C&D waste separation at source Remaining stony fraction C&D waste recycling plants Classifying municipal solid waste separation at source Remaining municipal solid waste incineration (MSWI) Landfill ban on cars organized selective demolition Powder coal fly ashes 100% is used as clinker substitution Blast furnace slags 100% is used as clinker substitution Many materials still landfilled or applied in low grade applications Examples: MSWI by-products, waste waste glass, converter slags, C&D waste From ecological and economical point of view undesirable 6/13/2017 PAGE 2
Dutch renewable energy production 10 Other biomass combustion Energy production (%) 8 6 4 Co-firing biomass in power plants Municipal solid waste incineration Solar power Biogas 2 Wind energy 0 1990 1995 2000 2005 2010* Year Hydropower Biomass fly ashes Paper sludge fly ash MSWI by-products 6/13/2017 PAGE 3
Waste-to-Energy Waste-to-Energy plants Europe Waste-to-Energy Plants operating in Europe (not including hazardous waste incineration plants) Norway 17 1.58 Sweden 33 5.7 Finland 9 1.2 Estonia 1 0.22 Latvia Waste thermally treated in Waste-to-Energy Plants (in million tonnes) 2014 Portugal 3 0.97 Ireland 1 0.22 Spain 12 2.5 Denmark 26 3.5 United Kingdom 32 7.9 Netherlands 12 7.6 Germany Belgium 99 25 18 3.3 France 126 14.7 Luxembourg 1 0.13 Switzerland 30 3.8 Poland 1 0.04 Czech Republic 3 0.64 Austria 11 2.4 Slovenia Italy 43 6.3 Croatia Lithuania 1 0.14 Slovakia 2 0.19 Hungary 1 0.38 Romania Greece Bulgaria
Use as building material Solid Waste Incineration Building Material Development 1) Reduction of solid waste 2) Generation of energy 3) Production of combustion residues 4) Poor physical and chemical properties 1) Consumption of raw materials 2) Environmental pollution 3) Energy consumption 4) Reuse and recycling of materials? Environment Economy Sustainable development 6/13/2017 PAGE 5
Municipal solid waste incineration (MSWI) Waste brought to tipping hall Combustion process High pressured steam production Turbines produce electricity, is distributed to national grid Unprocessed bottom ash Ferrous and non-ferrous metals and unburnt materials are removed APC-residues Clean flue released to atmosphere APC residues are used in industrial processes or disposed in a hazardous waste facility A B C D A: Bottom ash and grate siftings B: Boiler and economizer ash C: Fly ash D: APC residues 6/13/2017 PAGE 6
Chemical composition MSWI by-products Bottom ash 0-2 mm (% mass) MSWI Fly Ash A (% mass) MSWI Fly Ash B (% mass) Scrubber residue (% mass) Gypsum (% mass) MgO 2.30 1.50 0.45 0.30 - Al 2 O 3 9.95 5.30 3.0 - - SiO 2 34.05 11.15 6.30 0.80 0.15 SO 3 7.55 13.20 13.10 11.90 55.80 K 2 O 1.25 7.20 15.95 3.05 - CaO 26.15 30.20 26.30 35.95 42.30 Fe 2 O 3 13.10 5.10 2.20 0.20 0.01 Cl 0.2 15.25 24.20 46.0 0.80 Br - 0.30 0.45 0.30 0.01 Other 5.65 10.8 8.05 1.50 0.95 6/13/2017 PAGE 7
Reusing materials Film separator Air separator Compression of plastic and paper 6/13/2017 PAGE 8
Size dependency of BA leaching Fine fractions (< 0.125mm) are the most contaminated
Sieving of MSWI Bottom Ash glass particles from bottles and glasses; synthetic ceramics e.g. cement fragment, concrete, pottery, bricks, porcelain and gypsum minerals e.g. quartz (SiO 2 ), calcium carbonates (CaCO 3 ), lime (CaO) and feldspars (CaO. Al 2 O 3. 2SiO 2 ) Removal of metals and unburnt material Reuse of the coarse fraction as aggregate J.M Chimenos et al., Characterization of the bottom ash in municipal solid w aste incinerator, Journal of Hazardous Materials, 64, Issue 3, 1999, 211-22220 6/13/2017 PAGE 10
Liberation of fines - fines can be attached to surface of bigger fractions - wet sieving more effective in removing heavily contaminated fines 11
Coarse BA fraction as aggregate 6/13/2017 PAGE 12
Configuration of mineral BA components Mineral Extractable Mineral Nonextractable Ceramics & stones Glass 100% 100% 44 % Oxide composition (wt %) 75% 50% 25% Oxide composition (wt %) 75% 50% 25% 28 % 15 % 0% SiO₂ CaO Fe₂O₃ Residual 0% 14 %
Crushing of coarse BA Common practice Impact and/or jaw crushers Liberation of cemented and agglomerated materials after weathering To improve further treatment steps (e.g. metal extraction) Size reduction Improved technical quality Jaw crushing shows material-dependent fracturing Cum. finer (vol. %) Cum. finer (vol. %) Cum. finer (vol. %) Cum. finer (vol. %) 100 75 50 25 0 100 75 50 25 0 100 75 50 25 0 100 75 50 25 Mineral - Nonextractable Mineral - Extractable Ceramics and stones Glass 0 0,001 0,01 0,1 1 10 100 Particle size (mm)
Environmental legislation building materials Contaminant Shaped building materials [mg/m 2 ] Non-shaped building materials [mg/kg] IBC materials (until 2020) [mg/kg] Sb 8.7 0.32 0.7 As 260 0.9 2 Ba 1500 22 100 Cd 3.8 0.04 0.06 Cr 120 0.63 7 Co 60 0.54 2.4 Cu 98 0.9 10 Hg 1.5 0.02 0.08 Pb 81 2.3 2.1 Mo 144 1 15 Ni 400 0.44 8.3 Se 4.8 0.15 3 Sn 50 0.4 2.3 V 320 1.8 20 Zn 800 4.5 14 Br - 670 20 34 Cl - 110000 616 8800 F - 2500 55 1500 SO 2-4 165000 1730 20000 6/13/2017 PAGE 15 Soil Quality Decree
Environmental legislation landfill Inert Non-hazardous Hazardous No Landfill Contaminant [mg/kg] [mg/kg] [mg/kg] [mg/kg] As < 0.5 0.5-2 2-25 > 25 Ba < 20 20-100 100-300 > 300 Cd < 0.04 0.04-1 1-5 > 5 Cr < 0.5 0.5-10 10-70 > 70 Co - - - - Cu < 2 2-50 50-100 > 100 Hg < 0.01 0.01-0.2 0.2-2 > 2 Ni < 0.4 0.4-10 10-40 > 40 Mo < 0.5 0.5-10 10-30 > 30 Pb < 0.5 0.5-10 10-50 > 50 Sb < 0.06 0.06-0.7 0.7-5 > 5 Se < 0.1 0.1-0.5 0.5-7 > 7 Zn < 4 4-50 50-200 > 200 Cl - < 800 800-15000 15000-25000 > 25000 F - < 10 10-150 150-500 > 500 SO 4 2- < 1000 1000-20000 20000-50000 > 50000 Landfill Ban Decree 6/13/2017 PAGE 16
Environmental standards (testing methods) Leaching tests: Column, L/S = 10 Cascade, L/S = 10 Diffusion Other requirements for landfill: Diffusion test: less than 1% mass loss in 64 days Minimum 1 MPa after 28 days Cl - + SO 4 2- + Br - < 20% (composition!) or Inner landfill: 3 meters 6/13/2017 PAGE 17
Possible treatments Washing It reduces the level of contaminants by dissolution of soluble phases Crushing & milling It provides an optimization of physical and chemical properties of the by-products Pelletization It creates an external core around byproducts particles, fixing inside the harmful compounds (Hydro)thermal treatment It provides different temperature and pressure conditions, increasing the immobilization within the crystals
Suitable applications Cement wood wool composites Aggregates Concrete fillers Lightweight aggregates Cementitious binder Autoclaved aerated concrete
Properties MSWI bottom ash in time Leaching properties (0.32) (0.9) (616) (1730) 6/13/2017 PAGE 20
Application of MSWI BA in concrete mixtures Contaminant FCG 0-8 (mg/kg) FCG 2-40 (mg/kg) FCG 2-20 (mg/kg) Non-shaped building materials (mg/kg) Antimony (Sb) 0.34 0.32 0.41 0.32 Arsenic (As) < 0.050 < 0.2 0.1 0.9 Barium (Ba) < 0.60 < 0.6 0.28 22 Cadmium (Cd) < 0.0010 < 0.007 0.01 0.04 Chromium (Cr) 0.052 < 0.1 0.1 0.63 Cobalt (Co) < 0.030 < 0.07 0.1 0.54 Copper (Cu) 0.2 0.29 0.13 0.9 Mercury (Hg) 0.0005 < 0.005 0.005 0.02 Nickel (Ni) < 0.050 < 0.2 0.1 2.3 Molybdenum (Mo) 0.61 0.81 0.36 1 Lead (Pb) < 0.10 < 0.3 0.1 0.44 Selenium (Se) 0.029 < 0.009 0.039 0.15 Tin (Sn) < 0.030 < 0.02 0.1 0.4 Vanadium (V) < 0.20 < 0.3 0.1 1.8 Zinc (Zn) < 0.30 < 0.7 0.2 4.5 Bromide (Br - ) < 0.50 2.45 4.1 20 Chloride (Cl - ) 3000 518 690 616 Fluoride (F - ) 5.5 0.33 72 55 Sulphate (SO 4 2- ) 6400 98 2300 1.730 6/13/2017 PAGE 21
Application of MSWI BA in concrete mixtures Flexural strength (MPa) 1.2 1.0 0.8 0.6 0.4 0.2 Reference 10% FCG 0-8 15% FCG 0-8 25% FCG 0-8 Contaminant FCG 0-8 (mg/kg) FCG 2-40 (mg/kg) FCG 2-20 (mg/kg) Non-shaped building materials (mg/kg) Antimony (Sb) 0.34 0.41 0.32 Arsenic (As) 0.9 Barium (Ba) 22 Cadmium (Cd) 0.04 Chromium (Cr) 0.63 Compressive strength (MPa) 0.0 70 60 50 40 30 20 10 0 3 days 7 days 28 days 91 days Curing time Reference 10% FCG 0-8 15% FCG 0-8 25% FCG 0-8 3 days 7 days 28 days 91 days Curing time Cobalt (Co) 0.54 Copper (Cu) 0.9 Mercury (Hg) 0.02 Nickel (Ni) 2.3 Molybdenum (Mo) 1 Lead (Pb) 0.44 Selenium (Se) 0.15 Tin (Sn) 0.4 Vanadium (V) 1.8 Zinc (Zn) 4.5 Bromide (Br - ) 20 Chloride (Cl - ) 3000 690 616 Fluoride (F - ) 72 55 Sulphate (SO 4 2- ) 1730 6/13/2017 PAGE 22
Application of MSWI BA in concrete mixtures Flexural strength (MPa) 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Reference 20% FCG 2-20 1 day 7 days 34 days 56 days Curing time Contaminant Crushed sample [mg/kg d.m.] Shaped sample [mg/m 2 ] Shaped building materials [mg/m 2 ] Antimony (Sb) 0.01 0.4 8.7 Arsenic (As) < 0.05 4.0 260 Barium (Ba) 6.6 20 1500 Cadmium (Cd) < 0.001 0.1 3.8 Chromium (Cr) 0.08 4.0 120 Cobalt (Co) 0.04 2.4 60 Copper (Cu) 0.33 4.0 98 Mercury (Hg) < 0.0004 0.0 1.5 Nickel (Ni) < 0.05 4.0 81 Molybdenum (Mo) 0.021 0.8 144 Lead (Pb) 0.82 8.0 400 Selenium (Se) < 0.007 0.6 4.8 Tin (Sn) < 0.02 1.6 50 Vanadium (V) < 0.099 8.0 320 Zinc (Zn) < 0.2 16 800 Bromide (Br - ) < 0.5 2 670 Chloride (Cl - ) 41 80 110000 Fluoride (F - ) 3.2 96 2500 Sulphate (SO 2-4 ) 26 960 165000 6/13/2017 PAGE 23
Application of MSWI BA in concrete mixtures Flexural strength (MPa) 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Reference 20% FCG 2-20 1 day 7 days 34 days 56 days Curing time Contaminant Crushed sample (mg/kg d.m.) Shaped sample (mg/m 2 ) Shaped building materials (mg/m 2 ) Antimony (Sb) 8.7 Arsenic (As) 260 Barium (Ba) 1500 Cadmium (Cd) 3.8 Chromium (Cr) 120 Cobalt (Co) 60 Copper (Cu) 98 Mercury (Hg) 1.5 Nickel (Ni) 81 Molybdenum (Mo) 144 Lead (Pb) 400 Selenium (Se) 4.8 Tin (Sn) 50 Vanadium (V) 320 Zinc (Zn) 800 Bromide (Br - ) 670 Chloride (Cl - ) 110000 Fluoride (F - ) 2500 Sulphate (SO 2-4 ) 165000 6/13/2017 PAGE 24
Washing/heating/pelletizing of fine solid waste Washing Remove of soluble salts (Cl, SO 4, etc.) Thermal treatment (550 o C) Reduction of heavy metals (Cu, Sb, etc.) leaching Pelletization Recycle and reuse fine bottom ash to produce artificial aggregate Disc/pan pelletizer 6/13/2017 PAGE 25
Washing/thermal/pelletizing of fine solid waste MSWI bottom ash fines properties - negative Highly porous material Containing contaminants (heavy metals and salts) Metallic aluminum (expansion risk) High 1 costs for general treatment 2 3 Cold bonded pelletization with binders - positive Controlling size for application in concrete Density control Pellet strength Spherical particle size for better flowability Immobilization by binders (S/S) Pre-reaction of metallic aluminum Low cost 6/13/2017 PAGE 26
Washing/thermal/pelletizing of fine solid waste Properties of the artificial aggregates Specific density 2.5 g/cm 3 Loose bulk density 980 kg/m 3 belong to lightweight aggregate according to EN standards Crushing resistance 7.5 N/mm 2 higher than other artificial aggregate in literature Water absorption 14.5% lower than other LW artificial aggregate in literature The leaching of the sulphate, copper and antimony is well under limit value. 6/13/2017 PAGE 27
BA as a valuable resource Extraction of water glass/mesoporous silica Silica: Si-O-Si polymer network Mesoporous: from 2 to 50 nm. High surface area Uses: catalysis, drug delivery and separation Preliminary results using BA as a silica source. 28
Summary and conclusions Incineration and after treatments should be done with care, leading to clean ashes and APC residues. Several incineration by-products were selected and investigated in terms of physical and chemical properties Depending on application, compliance with legal requirements Leaching tests and/or composition requirements Particle size (physical) and mineral oxide (chemical) engineering Maximize waste content while minimizing added materials Upgrade to non-hazardous immobilisate and building material is possible Use as (silica) resource Cost-effective solutions 6/13/2017 PAGE 29
Conclusion Waste-to-Energy Plants Waste-to-Energy-and-Building-Materials Plants 6/13/2017 PAGE 30
Thank you! Questions, thoughts, ideas 6/13/2017 PAGE 31