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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

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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

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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

Mechanical treatment

Dry recyclables

Rejects

MSWAD Aerobic

Biogas „Compost“

Make energy & landfill

Produce Biogas & soil improver

Mechanical treatment

Dry recyclables

RDF I

MSWAD Aerobic

Biogas Landfill

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The lowest cost option for MBT

Partial MBT treatment with landfilling

Mechanical treatment

Dry recyclables Landfill

MSWAD Aerobic

Biogas LandfillLandfill

The ecologically best solution

Household Waste Grey RDF I Waste OFMSW Surface Application RDF II

Fertilizer Compost

Source Separation

Digestion

Mechanical Separation

Digestion

Post-treatment

Dedicated Combustion

Thermal treatment

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Percentage of Population hooked to an MBT

Martin Steiner, 2005

Countries with the highest share of MBTInstalled capacity of operational facilities by location

0 500 1000 1500 2000 2500 3000

Israel

Portugal

Japan

Turkey

Poland

UK

Canada

Belgium

France

USA

Austria

Netherland

Australia

Spain

Germany

Italy

Input Capacity (in 1'000 Tonnes per annum)

6'500

5'700

Total installed capacitiy approx. 20m tons

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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: BiodegmaBTA/MATHaaseHeseHorstmannISKALindeNehlsenRosRocaSutco

UK: CIVICNew EarthWastec

Austria: KomptechVKW

Italy: SCTEcoDeco

NL: Grontmij

CH: Kompogas

B: OWS

SF: CitecRumen

F: Valorga

USA: Bedminster

Israel: ArrowBio

Canada: Wright

MBT with AD: Dry digestionExample: Valorga

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MBT with AD: Dry digestionExample: Valorga

MBT with AD: Dry digestionExample: Valorga

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MBT with AD: Wet digestion (1)Example: Omrin

1 = waste storage2 = separation unit3 = washing unit4 = digestion unit5 = power plant

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MBT with AD: Wet digestion (2)Example: Omrin

220,000 tonnes

100%

Paper/plastics

16%

Ferro/

non-ferro

3%

RDF

40%

(OFMSW)(41%)

Inert

6%

Water

suspension

20750

(9,4%)

Sand5%

Residue3%

Organics36%

Biogas

6%

Effluent14%

Digestate

16%

Separation unit Washing unit Digestion unit

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MBT with AD: Wet digestion (3)

Example: Omrin

MBT with AD: Percolation (1)

Example: UR-3R Sydney

Plant thruput: 175’00 tpyLandifill diversion: 80%

Income from: gate feeelectricity

Recycled prodOGM

CO2-equivalent

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MBT with AD: Percolation (2)

Example: UR-3R Sydney

MBT with AD: Percolation (3)

Example: UR-3R Sydney

Percolation Organic fraction

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MBT with AD: Percolation (4)

Example: UR-3R Sydney

Digestion

MBT with AD: Percolation (5)

Example: UR-3R Sydney

Composting & Refining

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Can we afford MBT ?

Type calculations based on the percolation system: 1. Mass balance

Household waste

Mech. treatment

Fe 3% > 120mm 12%

Percolator

Sand3%

Water11.3%

Degradation 1%

DigesterBiogas8.5%

Composting Mech. treatment

Water10%

> 60mm 8%

Landfill43%

MBT before an existing incinerator

Household waste

Small business waste

Household waste

Mech. treatment

Fe 3%

> 120mm 12%

Percolator

Sand3%

Water11.3%

Degradation 1%

DigesterBiogas8.5%

Incineration

140‘000 tpy

86‘000 tpy

17‘000 tpy

+ 25‘700 tpy small business waste+ 11‘300 tpy household waste

103 € per t

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MBT & incineration: Household waste„grey bag“

Household waste

Household waste

Mech. treatment

Fe 3%

> 120mm 12%

Percolator

Sand3%

Water11.3%

Degradation 1%

DigesterBiogas8.5%

Incineration

140‘000 tpy

86‘000 tpy

17‘000 tpy

+ 48‘400 tpy household waste

79 € per t

MBT, incineration & landfill

> 60mm 8%

Household waste

Mech. treatment

Fe 3%

> 120mm 12%

Percolator

Sand3%

Water11.3%

Degradation 1%

DigesterBiogas8.5%

Composting Mech. treatment

Water10%

Landfill43%

Incineration

140‘000 tpy

17‘000 tpy 11‘000 tpy

60‘000 tpy

28‘000 tpy RDF @ 150€/t60‘000 tpy landfill @ 40€/t

79 € per ton

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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