Mechanical-Biological Treatment : A must for future waste upgrading technologies
Arthur Wellinger Task Leader Task 37
What is MBT ?
• Mechanical-Biological-Treatment (MBT) processes household waste by mechanically separating some parts of the waste and biologically treating others
• MBT is a very flexible waste management tool but seldom a stand-alone technology
• MBT is a well established waste upgrading technology in most parts of Europe
1 The two basic functions
• M(echanical treatment) refers to sorting, size reduction, separation and sieving technologies achieving separation of potentially useful products and streams for biological treatments
• B(iological treatment) refers to anaerobic and/or aerobic or processes which convert the organic fraction into a compost-like material and biogas
What are the goals of MBT ?
• Help to meet landfill diversion targets • Boost recycling performance • Reduce the need for incineration • Improve product quality • Avoid source separation • Minimise waste processing cost • Reduce implementation time (less public concern)
Yes, but not everything at the same time
2 What type of waste is MBT suited ?
Entire MSW: Black bag • Key role plays the mechanical part. It has to be robust and flexible • Hand sorting has often to be included • M is to prepare input to B rather than recycling Source separated residual waste: Grey bag • Lower quantities of waste for M treatment • Less sophisticated M (shredding, sorting, etc.)
The most widespread options for MBT
Make energy & Mechanical AD Aerobic landfill treatment MSW
Dry RDF I Biogas Landfill recyclables
Produce Biogas Mechanical & soil improver treatment AD Aerobic MSW
Dry Rejects Biogas „Compost“ recyclables
3 The lowest cost option for MBT
Mechanical treatment AD Aerobic MSW
Dry Landfill recyclables Landfill Biogas Landfill
Partial MBT treatment with landfilling
The ecologically best solution
Household Waste
Source Grey Mechanical RDF I Separation Waste Separation
Thermal Digestion OFMSW treatment
Surface
Post-treatment Application Digestion
RDF II Fertilizer Compost
Dedicated Combustion
4 Percentage of Population hooked to an MBT
Martin Steiner, 2005
Countries with the highest share of MBT Installed capacity of operational facilities by location
Italy 6'500
Germany 5'700 Spain
Australia
Netherland
Austria
USA
France
Belgium
Canada
UK
Poland
Turkey
Japan
Portugal
Israel
0 500 1000 1500 2000 2500 3000 Input Capacity (in 1'000 Tonnes per annum)
Total installed capacitiy approx. 20m tons
5 Commercially available MBT systems
In total there are more than 50 technology providers claiming experience with MBT. Only 26 processes have full-scale operating plants:
Germany: Biodegma UK: CIVIC NL: Grontmij BTA/MAT New Earth Haase Wastec CH: Kompogas Hese B: OWS Horstmann Austria: Komptech ISKA VKW SF: Citec Linde Rumen Nehlsen Italy: SCT F: Valorga RosRoca EcoDeco Sutco USA: Bedminster Israel: ArrowBio Canada: Wright
MBT with AD: Dry digestion Example: Valorga
6 MBT with AD: Dry digestion Example: Valorga
MBT with AD: Dry digestion Example: Valorga
7 MBT with AD: Wet digestion (1) Example: Omrin
4
3 2 1 5
1 = waste storage 2 = separation unit 3 = washing unit 4 = digestion unit 5 = power plant
MBT with AD: Wet digestion (2) Example: Omrin
Separation unit Washing unit Digestion unit
Water Paper/ RDF suspension Inert Biogas plastics 40% 20750 16% (9,4%) 6% 6%
(OFMSW) Organics Digestate 220,000 (41%) 36% 16% tonnes 100%
Ferro/ Sand Residue Effluent non-ferro 5% 3% 14% 3%
8 MBT with AD: Wet digestion (3)
Example: Omrin
MBT with AD: Percolation (1)
Example: UR-3R Sydney
Plant thruput: 175’00 tpy Landifill diversion: 80% Income from: gate fee electricity Recycled prod OGM
CO2-equivalent
9 MBT with AD: Percolation (2)
Example: UR-3R Sydney
MBT with AD: Percolation (3)
Example: UR-3R Sydney
Percolation Organic fraction
10 MBT with AD: Percolation (4)
Example: UR-3R Sydney
Digestion
MBT with AD: Percolation (5)
Example: UR-3R Sydney
Composting & Refining
11 Can we afford MBT ?
Type calculations based on the percolation system: 1. Mass balance
Biogas Digester 8.5%
Household Mech. Mech. Composting waste treatment Percolator treatment
> 120mm Sand Fe 3% Degradation Water > 60mm 12% 3% 1% 10% 8% Water 11.3% Landfill 43%
MBT before an existing incinerator
+ 25‘700 tpy small business waste + 11‘300 tpy household waste Household Small business waste waste 103 € per t
Biogas Digester 140‘000 tpy 8.5%
Household Mech. waste treatment Percolator Incineration 86‘000 tpy Fe 3% Sand Degradation 3% 1% Water > 120mm 11.3% 12% 17‘000 tpy
12 MBT & incineration: Household waste „grey bag“
+ 48‘400 tpy household waste Household waste 79 € per t
Biogas Digester 140‘000 tpy 8.5%
Household Mech. waste treatment Percolator Incineration 86‘000 tpy Fe 3% Sand Degradation 3% 1% Water > 120mm 11.3% 12% 17‘000 tpy
MBT, incineration & landfill 28‘000 tpy RDF @ 150€/t 60‘000 tpy landfill @ 40€/t 79 € per ton 60‘000 tpy
Biogas Landfill Digester 8.5% 43% 140‘000 tpy
Household Mech. Mech. Composting waste treatment Percolator treatment
Sand Fe 3% Degradation Water > 60mm 3% 1% 10% 8% > 120mm Water 12% 11.3%
Incineration 17‘000 tpy 11‘000 tpy
13 Conclusions
• MBT is a low cost and reliable option within the processes of waste upgrading • It is particularly well suited in developed countries where landfill capacities are still available and emissions are to be reduced •It is a low cost option to allow more waste to be treated in an existing incineration plant • It is an excellent and cost efficient tool in developing countries where most of the (organic rich) waste is still dumped • It is an excellent means to produce soil improvers for arid areas
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