199 NT 0001 RevA MSW Characterization

PT-PP

SOLO PROJECT

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MSW characterization

(methodology)

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A 11-Nov-16 First issue L.BONORA S.M. -

INDEX

1. PURPOSE

The purpose of this document is to provide PT-PP with a methodology to define the basic characteristics of the waste that will be entered in the plant process, considering the fact that these characteristics influence the quality of the syngas, hence the performance of the power generation and subsequent revenues, as well as the operation constraints for the RDF preparation and the quantity of residues, hence the subsequent costs.

2. WASTE CHARACTERISTICS

Waste is heterogeneous by nature. In any kind of municipal solid waste project, whichever the elimination or transformation process, knowing better the quality of the incoming waste is part of the basics to design the facility. The characteristics which are relevant for the chosen gasification process and the energy recovery by gas engines are:  Humidity (drying is anyhow necessary before the gasification island, and water content will determine the sizing of the drying unit and power required for this stage),  Elementary composition (C, H, N, O, S, Cl, etc.), which is essential to the production of syngas and the design & sizing of the gas purification package. Elementary composition can be measured by laboratory tests (preferable) but can also be assessed by typical evaluations if the material content is identified. Our proposal is to make a complete sorting into 13 categories of waste which can be related with typical elementary compositions:

 Category 1 : ORGANICS 1.1. Food waste

1.2. Yard trimmings (garden waste) 1.3. Wood

 Category 2 : PAPER  Category 3 : BOARD

 Category 4 : COMPLEX WASTE  Category 5 : TEXTILE

 Category 6 : HYGIENIC TEXTILE

 Category 7 : PLASTICS (PET, HDPE, LDPE, PVC, PP and PS)

 Category 8 : UNCLASSIFIED COMBUSTIBLE WASTE (Miscellaneous organics)  Category 9 : GLASS

 Category 10 : METAL (ferrous + non ferrous)

 Category 11 : UNCLASSIFIED UNCOMBUSTIBLE WASTE (Miscellaneous inert)  Category 12 : SPECIAL WASTE

 Category 13 : FINES

 Size, while some big parts are not suitable for the process and have to be removed thoroughly before; our methodology implies to remove all big parts before the identification/sorting process.

 Variability, in so far as both the gasification reactor’s working parameters and the Jenbacher gas engines following cannot cope with too brutal variations in the RDF input quality. This parameter can be dealt with only by repeating measures on a large number of samples. However, the design of the plant will anticipate that it is not easy to be sure about the composition evenness of the waste composition, and therefore provides buffers before and after the RDF preparation, where homogenisation can be completed.

3. METHODOLOGY

In principle, measurements involve taking a large number of samples, each one of which has to be representative of the whole. Everyone agrees that this phase is the trickiest one: each street, each district, each area, every season has its own characteristics. Usually, these characteristics are taken into consideration in the sampling selection process, requiring many setbacks and an iterative process. Practically, this type of sampling will not be feasible in our time schedule, and we will have to rely on random sampling on the landfill and on incoming trucks. However, we highly recommend to follow such a survey on a more long term basis, during the FEED, in order to requalify the incoming waste taking into account local characteristics of the main production areas or population types.

As said, practically, all the waste coming into the plant will have been manually processed on the landfill beforehand: people working on the landfill will have removed all what they believe can be recycled. This does not mean it will be free of big size

material or gas bottles or even spray cans, which can be dangerous to the plant’s

equipment. The most relevant samples of what we will get on the plant is hence the waste after this manual picking for recycling, where it will be possible to see what is left and theoretically what will have to be dealt with on the plant itself.

“Representative” samples will hence be taken from the landfill:

 On incoming truck’s unloaded fresh waste, after scavengers picking-up activities  On old waste, already stored on site since a few months, in order to check the

feasibility of using the Gasifier to depollute the existing landfill from long term stored waste.

The number of samples taken will of course reduce the size of the confidence interval and make the measurements more relevant. At least 10 samples of each type should be made as a starting point.

For each representative sample, a quartering method is used to reduce the size of each sample down to a value which can be handled (see Appendix 1), which makes it feasible to process all 20 packages within the 2 weeks of the measurement campaign.

The equipment required for processing the samples and measuring is listed in Appendix 6.

Appendix 1 Sample reduction

The truck coming into the sample identification area contains a large sample (around 1 tonne). This sample has to be treated in order to identify all types of material inside.

 By sorting out all big size elements (which are never supposed to enter the plant)  By reducing the size of the sample to be sorted by categories

Let us recall that the incoming waste in this truck is coming directly from the landfill, either from the “old” waste package, or from fresh waste just coming from the city waste collection, but just after the scavengers have taken their part of recyclables.

A clear idea of the total weight of the incoming package should be known, by passing the vehicle on a weighbridge (before and after unloading or loading)

The treatment of this large package will be following the next procedure: 1. Open all bags to let the content out  pack n°1

2. Sort out all big size elements waste, weigh them and identify them  Big size = not entering a sphere of about 30 x 30 cm

3. mix the waste with a mechanical shovel  constitution of pack n°2

4. once mixed, poor the waste from pack n°2 over 4 big boxes

5. pick the 2 diagonal boxes, and keep the waste inside these 2 boxes  pack n°3. Remove the waste from the two other boxes away ( CAN BE USED TO MEASURE DENSITY according to Appendix 5; Then returns back to the landfill) 6. repeat operation 4/ and 5/ (at each time, switch the 2 diagonals) until there is no

waste left in pack n°2

7. repeat operations 3/ 4/ and 5/ on pack n°3 to pack n°4, pack n°4 to pack n°5 etc. until the size of the last pack is reduced down to 100 to 150 kg

Appendix 2 Drying procedure

 spread the sample over a number of trays so that the height of the sample in any tray is not more than 25cm

 place in a fan-assisted oven at 90 ± 2°C for 24 hours under normal pressure (1 bar)  Duration: 24 hours or until “constant weight”.

 “Constant weight” is defined by a weight variation equal or less than 1% between 2 successive weighings at 2 hours interval, the drying process being continued during both weighings.

 It is advised to do the identification method (Appendix 3) on dry waste while it is more secure and clean for the workers, and the results are better (better separation of fines from the other types of waste, better working conditions). This means, each

sample about 100 to 150 kg must be passed through the drying process.

For other tests (when identification by categories are not achieved afterwards), the quantity of material used a humidity test should not be less than 2 kg, with the possibility of prior quartering in order to reduce the sample size.

 The humidity is calculated by the formula:

%wet = 𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑊𝑒𝑖𝑔ℎ𝑡 (ℎ𝑢𝑚𝑖𝑑)−𝐹𝑖𝑛𝑎𝑙 𝑊𝑒𝑖𝑔ℎ𝑡 (𝑑𝑟𝑦)

𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑊𝑒𝑖𝑔ℎ𝑡 (ℎ𝑢𝑚𝑖𝑑) 𝑥 100

Appendix 3 Identification procedure by categories

The identification methodology by categories starts with sorting all the material by size on a sorting table composed of 3 perforated plates and a recuperation box:

- a first plate, on the top, with 100 mm diameter holes, - a second plate, intermediate, with 20 mm diameter holes, - a third plate, on the bottom, with 8 mm diameter holes, - a recuperation box without holes on the ground.

As a result, the waste is parted in four categories on the sorting table: - the BIG PART, whose diameter is more than 100 mm,

- the MEDIUM PART, whose diameter is between 20 and 100 mm, - the SMALL PART 8 - 20 mm, whose diameter is between 8 and 20 mm, - the FINE PART < 8 mm, whose diameter is less than 8 mm.

Each part is weighed by size.

The BIG PART is sorted in 12 categories according to the following table:

CATEGORIES DESCRIPTION

Category 1 : ORGANICS ,

Subcategory 1.1 Food waste Subcategory 1.2 garden waste Subcategory 1.3 wood

Category 2 : PAPERS Newspaper, scholar paper... Category 3 : BOARD Packing cardboard...

Category 4 : COMPLEX WASTE Waste composed of several material (ex : milk and fruit juice brick = board+aluminium)

Category 5 : TEXTILE Used clothes and rags

Category 6 : HYGIENIC TEXTILE Baby’s nappies, handkerchiefs, … Category 7 : PLASTICS PET, HDPE, LDPE, PVC, PP and PS Category 8 : UNCLASSIFIED

COMBUSTIBLE WASTE

Wood, bones, leather...

Category 9 : GLASS Bottles, pots, etc…

Category 10 : METAL Iron, others (aluminium…) Category 11 : UNCLASSIFIED

UNCOMBUSTIBLE WASTE

Ceramic, stones...

During the sorting phase, each different category of waste is put in a special plastic garbage can of around 50 litres. When the garbage can is full, it is weighed and its content is conserved.

After sorting and weighing the BIG PART, about 1/8 of the MEDIUM PART is sampled, sorted, by the same categories and weighed. Results are multiplied by 8 in terms of total weight to recover their true representation in the initial sample.

The SMALL PART 8-20 mm and the SMALL PART <8 mm are not sorted but each of these parts is weighed. *** for each of these SMALL PARTS, determination of the % of volatile content by burning – See Appendix 4 ***

The results of this test are implemented in the Excel file template provided (attached) so as to convert the results into a representative model.

Appendix 4 Measuring the inert content

The inert content in a sample can be determined by measuring what is left after burning the sample thoroughly with a gas burner on grills and mixing it during the process. The weight of the sample is measured before and after burning.

The inert content can be expressed in % of original weight. This test will be conducted separately on:

 the small parts < 8 mm

Appendix 5 Measuring the density of waste

The density is determined on the mixed waste after being dumped on the sorting area (see stage n°5 in Appendix 1.

A 200 liters barrel is filled with waste and weighed. The waste are not compacted in the barrel.

The density is calculated by the formula:

Appendix 6 Equipment list for waste sample processing

A covered shed (the sorting must take place in a clean and large place. It must also be covered to prevent the evaporation which can modify the results).

 A vehicle (truck without compaction) for collection of the samples

 A mechanical shovel, bobcat or other device (to lift and mix the samples)  1 scale 0-100 kg, precision 0.100 kg

 1 scale 0-10 kg, precision 0.010 kg

 1 sorting table with 4 plates : 100 mm, 20 mm, 8 mm, 0 mm

 15 containers (boxes and bags) of around 50 litres each for storing and weighing separated fractions

 1 magnet (for separation between ferrous and non-ferrous metals)  2 shovels, 2 rakes, brooms,

 overalls, gloves, masks  first aid kit

 a 200 litres barrel for calculation of waste density

 fan assisted ovens (for moisture content measurements) with trays  some large plastic sheets

 additional containers for buffer storage