reinnova huber humer-handout_2011_v1

Los retos en la gestión de residuos urbanos en una economía globalizada

Els reptes en la gestió de residus urbans en una economia globalitzada

Challenges in waste management in a globalized economy

ORGANIZADO POR: CON LA COLABORACIÓN DE:

Different models of MBT ‐ advantages anddisadvantages

Marion Huber‐Humer

Los retos en la gestión de residuos urbanos en una economía globalizadaEls reptes en la gestió de residus urbans en una economia globalitzada


E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

2

The amount of disposed biologically degradable wasteshould be reduced to

–75% until 2006–50% until 2009–35% until 2016versus base year 1995.

EU Landfill Directive: “…. in order to “reducemethane generation in the landfills and therelated global warming effects”



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

3

Pretreatment StrategiesMSW-Incineration MBT Strategy

Residual waste (low organic content)

incineration

residues (slag, ash)

landfill

Mechanical separation

high calorific fraction(RDF)

easily degradable fraction

incineration humification

Residues(flyash) MBT-material

landfill landfill

carbonation, solidification



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

4

MBT-Waste: Carbon and Nitrogen FixationWhile thermal treatment leads to an immediate release of the entire carbon in form of CO2 (bothbiogenic and fossil) into the atmosphere, disposal of MBT‐material allows to store …

…a substantial part (approx. one third) of carbon in the landfill as stable organic substance for medium‐to long‐term time. The other part is released in form

of climate‐neutral CO2 during aerobic biologicaltreatment.



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

C‐sink MBT‐landfillCorg content:

0

5

10

15

20

25

0 50 100 150 200 250

Alter (Wochen)

Cor

g (%

TM

) MW: ~ 17 % TM

MW: ~ 2 % TM

Maturity (weeks)

Mean aprox. 17% DM

Mean aprox. 2% DM

% D

M



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

C‐sink MBT‐landfillCorg content of MBT material versus incineration residues:

mean Corg of MBT‐Output: ~ 17 ± 2,5 % DMmean Corg of waste incineration bottom ash:

~ 2 ± 1,5 % DM

Difference: ~ 15 % DM



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Optimisation of waste streamsWet waste (input‐material):⇒MBT, because vaporisation of water reduces the heating value of waste

Material with high content of carbonates⇒ decay of carbonates during incineration => release of CO2; fixation of C during MBT is more favourable



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Biodrying Strategy„Trockenstabilat“

MBTSplitting Strategy

reducing water content by biological heating

Incineration / interim storage

residues (slag, ash)

landfill

Mechanical separation

high calorific fraction(RDF)

easily degradable fraction

incineration humification

Residues(fly-ash)

MBT-material

landfill landfill



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Main differences of MBT strategies

Preparation for landfilling,Creation of C‐ and N‐pool

Preparation for recovery, storage, transportation, thermal treatment,…

Longterm stabilization(mineralisation and humification)

No longterm biologicalstabilization !!

MBT‐concept„Bio‐drying“



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Mass balance (%) – examples from Austrian MBT- plants

plant A B C/biodrying Dplant input t/a 53.000 75.000 30.000 41.000

RDF I 39% 13% 40% 53%

input biology 61% 87% 60% 47%

loss bymineralisation 20% 40% 17% 24%RDF II 18% 7% 36% -

MBT-landfill 23% 40% 7% 23%



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

11

Biological step: aerobic or anerobic/aerobic

‐ sensitive microbial process(tendency to form scum, …)

‐ robust microbial process and faster degradation kinetics

‐ additional (complex) technicalequipment (pre‐preparation of waste)‐ higher work input => costs‐ treatment of digester outputmaterial (additional aerobic stepneeded to achieve required landfillparameters)

‐Maintanence of specific plant sections (aeration equipment, etc.)‐management of exhaust air‐many long‐term experiences and know‐how

‐ recovery of biogas (energyrecovery)

‐ longterm stabilization(mineralisation and humification)

anaerobic /aerobicaerobic



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

12

aerobic processaerobic process

MBT ‐ Biological Treatment

organic matter is used by microbes as source of energyand nutrient; therefore microbes need:

= GlucoseC6H12O6

6 CO2 + 6 H2O + 2.880 kJ/molC6H12O6 + 6 O2

oxygenoxygen

balanced nutrient content balanced nutrient content (C/N)(C/N)

waterwater (oxygen + nutrients available only solved ) (oxygen + nutrients available only solved )



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

13

‐higher costs‐higher energy demand

‐ cost‐efficient‐ low energy demand

‐ complex technical equipment‐ online‐management („error‐prone“)‐ high maintanence activities

‐ problems with odor emissions /airemissions (legal requirements!)‐ longer treatment durations‐ know‐how and experiencesrequired for optimal processmanagement

‐ Closed systems with managementof exhaust air

‐ „open“ windrow rotting process

„High tech“„Low tech“



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

14

MBT ‐ Low Technique Systems



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

15

MBT ‐ Low Technique Systems

Katsdorf / UA, 1976



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

16Aich Assach / Styria, 1984

MTB ‐ Low Technique Systems



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

17

In Vessel System ‐ Batch Type: Stockerau/Austria



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

18Spanien 2011

In Vessel System ‐ Batch Type

output

input

leachatere‐circulation

waste air re‐circulated air

fresh air

supply airgrid floor

leachate



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

19

Forced Aerated System: In Vessel (Reactor) System

disadvantage: computer reacts to measurement (does not know the reason for the changed value)

system may crashsystem may crashwhen air amount

is to highmaterial dries out

and degradation stops

when air leavesthrough clefts

O2 in waste air remains high, but O2 is not consumed by microbes

air amount is reduced, microbes do not get enough oxygen



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Goals of MBT Regarding Final Disposal stability of organic mattersignificant reduction of CH4 generationsignificant reduction of BOD in leachatelong-term sink for C and Nsaving landfill volumeuniform geotechnical properties



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

21

Gas GenerationGas Generation Potential in Incubation Test -Impact of Mechanical Biological Pretreatment

Test Duration [days]

Gas

Gen

erat

ion

[Nl/k

g D

M]

0

50

100

150

200

250

300

0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480

Oberpullendorf DANO-OutputGS21 = 34 Nl/kg DS - acidification!

Siggerwiesen 3 weeksGS21 = 54 Nl/kg DS

Allerheiligen 5 weeksGS21 = 35 Nl/kg DS

Allerheiligen 5 weeksGS21 = 25 Nl/kg DS

Liezen 16 weeksGS21 = 4 Nl/kg DS

Oberpullendorf 20 weeksGS21 = 9 Nl/kg DS



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

22

….. after biological treatment methane gas production is reduced by 90-95%.

focus on the quality and properties of the landfilled waste (= internal barrier)



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Stability of Organic Matter – Limit Values Austria

Measuring methodsRespiration Activity < 7 mg O2/g DMGas Generation < 20 Nl/kg DM

To prevent landfilling of high calorific materials

Calorific Value < 6,600 kJ/kg DM



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er landfill emissions untreated MSW after MBT

gas production 130 – 300 m3/t DM << 24 m3/t DM

BOD in leachate up to 30,000 mg O2/lacidic leachate

10 – 350 mg O2/l

ammonium in leachate 240 – 10,000 mg NH4/l 100 – 350 mg NH4/l

Emissions - untreated MSW versus MBT-Waste



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

25

Impact on Leachate QualityImpact of Pretreatment on

COD-Concentrations in Leachate

CO

D [m

g O

2 / l

]

0

10,000

20,000

30,000

40,000

50,000

60,000

without MBPyoung

without MBPold

20% MBPold

> 50% MBPyoung

> 50% MBPold



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

26

Impact on Leachate QualityImpact of Pretreatment on

Ammonia-Nitrogen-Concentrations in Leachate

Am

mon

ia-N

itrog

en [m

g / l

]

0

2,000

4,000

6,000

8,000

10,000

without MBPyoung

without MBPold

20% MBPold

> 50% MBPyoung

> 50% MBPold



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Assumptions

• RDF-fraction 20 to 50%• ash content of the RDF av.15%• loss by mineralisation 20 to 40%• density of MBT- waste in landfill >1.3 t/m3

• density of MSW in landfill ~1.0 t/m3

⇒ up to 80% of landfill volume can be saved

MBT saves landfill volume !



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

positive

low permeability Kf < 10-9 m/slow amount of leachate

high compactionvolume reduction and reduced settlement

negative

fine particle size < 40 mm(calorific value < 6,600 kJ/kg DM)

reduced mechanical stability(lack of reinforcement by plastic)

Geotechnical aspects of MBT-Waste



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

29

Reduced fibre-cohesion and saturation of thepore volume at low moisture contents requirespecial methods of landfill operation

Landfilling at the dry side of optimum watercontent of the Proctor compaction curve

Accumulation of water on the landfill surfacemust be avoided through sufficient inclination

low hydraulic conductivity (kf =10-6 bis 10-9

m/s) and, thus, alterations in the stabilitybehaviour of the landfill

Separation of high-calorific plastic fractions & biologicaltreatment allow for higher waste density in the landfill



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Conclusions• Different concepts, each has pros and cons, no single solution! =>find suitable concept for specific waste (composition and properties) and individual situation• improvement of efficiency by optimisation of waste streams• MBT‐landfill => C and N sink (climate change!)



E. Binne

r, M. H

uber‐Hum

er, P. Lechn

er

Thank you for your attention!

reinnova huber humer-handout_2011_v1

Business

waste management

lech mbt

air waste

degradable waste

los retos en

longterm experiences

input biology

la colaboracin