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RELIABLE DATA FOR WASTE MANAGEMENT

September 25-26, 2008, Vienna, Austria

New MSW sampling and characterization methodologiesg

The dry product methodPh. WAVRER - BRGM

BRGM, Orléans - FRANCE

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MSW characterization in France

A little page of history

• 1993: MODECOM™ (French MSW characterization methodology).

– Characterization made on the collection vehicle.– Mass of sample: 500 kg.

• 1993: First national campaign of MSW characterization in France, based upon MODECOM™

• 1994-1997: Development of selective collection schedules.

• 199 Ad i f h MODECOM™ h d l

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• 1997: Adaptation of the MODECOM™ methodology for the selective collection.

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MODECOM™ sampling & sorting operations

500 kg

Sample to be sorted

10 x 50 kgLotCollection vehicle

MSWSample to be sorted

EEN

ING

Coarse(> 100 mm)

Medium(20-100 mm)

Fines(8-20 mm)

(< 8 mm)Optional

1/8 sorted Sorted in integrality

ORT

ING

Categories

SCRE

Sub categories

Unsorted

Quartering

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SO

Categories Sub-categories

ANALYSES(Moisture content, LOI, heavy metals,Heating Value, organic matter, etc…)

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2 French AFNOR standards

• NF X30-413: Constitution of a sample of

Derived from the MODECOM™ methodology

household waste contained in a waste collection vehicleRules for sampling MSW from a collection vehicle.

– Sampling of 500 kg formed by ten 50 kg increments.– Random sampling.– …

• NF X30-408: Characterization of a sample of household related wasteRules for characterization of MSW.

– Characterization made on wet (raw) material.– Screening with a double-screen (20 & 100 mm) sorting

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g ( ) gtable.

– Quartering of the 20-100 mm fraction.– Etc.

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Screening with a screen sorting table

> Screening on wet t i l i dmaterial carried

out within 24 hours after sample constitution

> 100 & 20 mm round mesh

> In option, 8 mm round mesh

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round mesh

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Some problems with MODECOM™

> Moisture contents measurement> Moisture contents measurement• For each category (after sorting): take « approximately » 2/3 of the

mass to be dried from the « coarse » fraction and 1/3 from the « medium » fraction.

Low precision for the moisture contents value

> Working on raw (wet) material• Sanitary and security hazards for the operators:

Unsatisfactory working conditions for optimal sorting results

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Some problems with MODECOM™> Screening• Biased results for the screening operation: fine particles remain

t kstuck on coarse ones.• Screening depends strongly on the operator care or skill:

poor reproducibility of the screening operation.

> Categories/Sub-categories distribution• Biased results: fines particles sticking problem.p g p• Possibility of sorting errors (poor working conditions).

> Difficulty to use characterization results for some studies• For example: expert evaluation of a plant, in relation with fines

ti l ( ti l t MBT )

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particles (composting plant, MBT, …)Problem with material mass balance

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Dry product method characterization

> Based upon previous Cemagref studies(B M )(B. Morvan)

> Take into account previous MODECOM™ experience and data• In order to minimize mass to be sorted without decrease the

f th ltaccuracy of the results.

> Main objectives:• To reduce bias observed at different stages.• To improve reproducibility.• T i i i it h d f th t

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• To minimize sanitary hazards for the operator.• To obtain usable data for expert evaluation of a plant .

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Dry product method characterizationConstitution of the 500 kgMSW sample

“Oddbits”~ 30kg

Opening all garbage bags

1/4 1/4 1/4 1/4

70°C Drying

Sample to be sorted~130kg

Sorted in integrality

AFNOR X30-413

Total moisturecontent

Quartering

Coarse>100 mm

Medium20-100 mm

Fines8-20 mm

<8 mm

Unsorted500 g

Scre

enin

gng Sorted in 5 kg

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Unsorted500 g(in option)

Sort

in

Categories Sub-categories

Analyses

Sorted in integrality

5 kgsorted

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« Oddbits »

> Element carrying heterogeneity because of its:• SizeSize,• Weight,• Composition,• Etc.

For example: a big cardboard box, a big shoe, a microwave oven, paint cans, …

> « Oddbits » are fully sorted from the 500 kg> « Oddbits » are fully sorted from the 500 kg MSW sample.• Their composition will be re-integrated into the final MSW

sample composition

> The remainder of the MSW sample (without

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p (« oddbits ») is quartered in order to be scaled down to about ¼ of its initial mass

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Quartering of the sample

> Objective: to divide the initial MSW sample (without « oddbits ») while maintaining proper representativity« oddbits ») while maintaining proper representativity

> Based upon the « alternate shovel » method

• ¼ of the initial sampleis kept for the next h t i ti tcharacterization steps

• ¾ are discardedafter weighing

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Drying of the entire sample

> « Oddbits » and quartered sample are driedOddbits and quartered sample are dried during five days at 70°C

• Result:Total moisture contentof the MSW samplep

• But:Moisture contents data about categories(or sub-categories)are lost

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are lost

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Screening of the dried sample

> Use of a trommel with successively 100, 20 and (in option) 8 mm round mesh( p )

Reproducibility of the screening method

• The fine particles problem is solvedwhen screeningwhen screeningdried material

• Screening no longerdepends on the operator: improved reproducibility

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reproducibility

• No bias for the particlesize distribution

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Sorting on dry material

> According to AFNOR X30-408 standard categories g gand sub-categories (revised in 2007) :• The integrality of « oddbits » and coarse elements (>100 mm) are

sorted.• After sub-sampling, about 5 kg of medium elements (20-100 mm)

are sorted.• In option, sub-sample and sort about 500 g of fine elements (8-20 p , p g (

mm). Elements <8 mm are not sorted.

> From screening/sorting results and sampling ratios,

MSW iti d tt

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MSW composition on dry matter

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Relation between wet and dry composition

> MODECOM™:• Moisture contents per category – MSW composition on wet matter

> Dry product method:• Global moisture contents – MSW composition on dry matter

To compare previous and new data

> Mean category humidity data base> Correspondence table (ADEME-Cemagref study)

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p ( g y)

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Dry method benefits

>Clean• The operator does not touch raw (wet) waste before drying.p ( ) y g

Drying allows to reduce bad smells. Working conditions aresafer and more comfortable.

>Accurate• Sorting errors are less frequent while working on dry material.• Systematic bias due to the fine particle sticking problemSystematic bias due to the fine particle sticking problem

strongly decreases (for instance, 20% fine particles are stuck onwet plastic films against only 1% on dry ones).• The fine particles (<20 mm) content becomes representative

when using a trommel for screening.

>Faster thus less expensive

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>Faster thus less expensive• The mass of sample to sort is lower, saving labour costs.

Results are independent of the operators

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MODECOM™/dry method comparison results

% sur sec

X30 408 X30 466 X30 408 X30 466 X30 408 X30 466 X30 408 X30 466

Niort Nantes Rennes Sables O% on dry mass

X30-408 X30-466 X30-408 X30-466 X30-408 X30-466 X30-408 X30-466Putrescibles 8,2 3,5 13,0 4,2 11,2 3,7 12,9 5,4 Papiers 15,5 15,0 19,2 19,1 12,1 11,4 13,9 14,1 Carton 8,4 8,6 6,8 7,1 6,7 7,1 6,6 6,6 Complexes 4,8 3,9 1,8 1,2 2,4 1,7 3,8 2,9 Textiles 3,7 3,6 0,3 0,3 0,9 1,0 4,8 5,0 Text sanitaires 5,2 7,1 7,0 6,9 4,8 4,9 5,6 5,7 Plastiques 18,2 15,9 18,3 16,3 15,2 12,2 19,9 18,1 Combustibles 8,5 5,9 3,2 2,9 6,2 6,3 6,8 6,4

PutresciblePaperCardboardCompositeTextileSanitary textilePlasticCombustible

Verre 3,8 3,3 7,3 7,0 8,3 7,9 5,1 4,7 Métaux 10,4 9,6 3,8 3,7 3,1 2,7 2,7 2,6 Incombustibles 1,3 1,4 4,5 4,9 12,6 9,1 7,6 5,7 DMS 0,8 1,1 0,8 0,8 1,0 0,7 0,4 0,4 <20mm 11,2 20,9 13,9 25,8 15,6 31,3 9,9 22,6

GlassMetalUn-combustibleSpecial wasteFine <20 mm

Sources:

A t i f lt b t th d i diffi lt

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An accurate comparison of results between methods is difficult:• MODECOM™ strongly depends on the operators• Dry method is independent of the operators

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Outcome

> A new French AFNOR standard: X30-466• Household and related refuse — Characterization method —

Dry product analysis

> Method used for the new French national campaign of MSW characterizationca pa g o S c a acte at o• Ademe study - in progress.

> Used for plant expert evaluations• Composting plants.

No more problem with material

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• MBT plants.• Etc.

No more problem with material balance

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Outside France

> Review study• Methods for household waste composition studies

(Dahlén & Lagerkvist, 2008)• Over 20 methods for waste sampling and analysis – all on

manual sorting of wet waste

> Validated standards: ASTM D5231 92 (2003)> Validated standards: ASTM D5231-92 (2003)• Standard Test Method for Determination of the Composition

of Unprocessed Municipal Solid Waste • Sorting on wet waste

> European approach: the SWA tool

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> European approach: the SWA tool• No practical application yet?

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Thank you!

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Sampling errors, from theory

> Theory of sampling and sources of error (Gy, y p g ( y,2003)• 1. Long-range heterogeneity fluctuation error• 2. Periodic heterogeneity fluctuation error• 3. Fundamental error• 4. Grouping and segregation errorp g g g• 5. Increment delimitation error• 6. Increment extraction error• 7. Preparation error

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