FUEL FROM WASTE

Jan NADZIAKIEWICZ

DEFINITIONS

Waste – any substance or product listed in Appendix no 1 to the Polish state Act, whom the owner wants to get rid of, plans to get rid of or must get rid of according the law.

Fuel – the substance beeing used as the heat source in the process of oxidation for industrial, technology, transport or living purposes. The fuel is composed of one or more combustible substances, mineral matter, water and some impurities

METHODS OF ENERGY RECOVERY FROM WASTE

Waste incineration.

Waste gasification.

Waste pyrolysis.

Fuel from waste.

Co-combustion with classical fuels (coal,

wood,).

Biogas.

Recovering energy from waste

Anaerobic Digestion can produce energy on a

small scale. It uses bacteria to break down organic

matter without oxygen in specially made digesters.

Gasification involves heating organic waste with a

reduced amount of oxygen and/or steam. It

produces a synthetic gas, known as syngas, which

can be burned independently in a boiler, engine or

gas turbine to produce electricity.

Recovering energy from waste

Pyrolysis is carried out in the total absence of

oxygen. It also produces an energy-rich gas and

solid residue. These can then be burned separately

to produce electricity. In some pyrolysis processes,

the gases are condensed into a liquid fuel.

Pyrolysis is a proven proces for producing diesel oil

from waste plastic and used tyres.

Incineration involves burning organic material

such as waste to produce electricity and heat.

Recovering energy from waste

Some landfill sites recover methane which is

produced naturally when biological waste breaks

down in the absence of oxygen. It can be used to

generate energy.

Mechanical and biological composting units can

produce solid recovered fuel (SRF). There are

some concerns over the toxicity of burning SRF.

Mechanical treatment of MSW can produce Solid

Recovered Fuel (SRF, RDF) for energy generation

(incineration, co-combustion …).

RDF DEFINITION

Refuse-derived fuel (RDF) or Solid Recovered Fuel / specified recovered fuel

(SRF), Alternative fuel is a fuel produced by shredding and dehydrating solid

waste (MSW).

No hazardous waste can be used!

RDF consists largely of combustible components of municipal waste such as

biodegradable waste and plastics (?)

Several methods have been developed to determine the biomass fraction of

RDF/SRF. The two methods developed (CEN/TS 15440) were the manual

sorting method and the selective dissolution method, an alternative method

was developed using the principles of radiocarbon dating.

The fuel made from waste IS STILL A WASTE and its utilization must follow

the regulations provided for waste!

Required reduction of bio-fraction of MSW

ELEMENTAL COMPOSITION OF MSW

MORPHOLOGY OF MSW

LHV = 9,24 MJ/kg

MORPHOLOGY OF MSW (SILESIA)

WASTE LHV [kJ/kg]

Paper and package materials 15000

Kitchen waste 14000

Tekstiles, rubber, leather 16300

Wood, straw, garden waste 15800

Fraction 0-5 mm 6700

Fraction 5-15 mm 11800

Thick granules 16300

The energy of municipal waste in Poland is 5 times greater

than the energy of Polish oil sources and it represents 20%

of total oil consumption in Poland.

LHV OF DRY WASTE COMPONENTS

HEATING VALUE OF WASTE

Average value for MSW 7500 - 9200 kJ/kg.

waste from large communities: 5020-10890kJ/kg;

waste from rural settlements: 4190-7540kJ/kg;

Big sized and demolishing waste: 10470-16750kJ/kg;

Industrial waste: 7540-12560kJ/kg.

THE LHV OF WASTE DEPENDS ON:

Combustible substance in the waste (organic

material).

Mineral substance (ash) contents.

Moisture of the waste.

“SOLID RECOVERED FUELS – SPECIFICATIONS

AND CLASSES” EN15359

EN15359 provides for methods of specification and classification of SRF

The standard prescribes the specification of certain physical and

chemical properties. These properties must be established by making

use of testing and analysis methods also developed by CEN/TC343.

The properties obligatory to specify include particle form and size,

moisture content, ash content, net calorific value, chlorine content

and each heavy metal mentioned in the Waste Incineration Directive

and the sum thereof.

Also SRF class and origin are obligatory to be specified. This means

that for each SRF produced all relevant heavy metals must be specified.

Producers are obliged to use the prescribed form of the standard to

specify SRF.

CLASSIFICATION OF SRF

The classification only aims to assign it to a class so that both producer and

user understand the type of SRF that they are dealing with.

CEN/TC343 has chosen to use the following three properties to quickly

describe (or classify) a SRF:

net calorific value (NCV): NCV is an indicator of the market value of SRF.

NCV is the most important property of SRF as it describes its value as a fuel.

Chlorine (Cl): Chlorine is unwanted in SRF as it contributes to corrosion. High

chlorine content will lower the market value.

Mercury (Hg): Of all relevant heavy metals, Hg is selected as an indicator of

the environmental quality of a SRF. Because of its high volatility, Hg is the

heavy metal most likely to be emitted. Cd and Tl are of limited relevance but

all heavy metals are obligatory parameters for specification according to EN

15359.

CLASSIFICATION OF SRF

Classification Statistical

measure

Unit Classes

1 2 3 4 5

(NCV) Mean MJ/kg (ar) ≥ 25 ≥ 20 ≥ 15 ≥ 10 ≥ 3

Classification Statistical

measure

Unit Classes

1 2 3 4 5

Chlorine (Cl) Mean % (d) ≤ 0,2 ≤ 0,6 ≤ 1,0 ≤ 1,5 ≤ 3

Classification Statistical

measure

Unit Classes

1 2 3 4 5

Mercury

(Hg)

Median

80th percentile

mg/MJ(ar)

mg/MJ(ar)

≤ 0,02

≤ 0,04

≤ 0,03

≤ 0,06

≤ 0,08

≤ 0,16

≤ 0,15

£ 0,30

≤ 0,50

£ 1,00

Example of classification:

SRF having a mean net calorific value of 19 MJ/kg (ar), a mean chlorine content of 0,5 % (d)

and a median mercury content of 0,016 mg/MJ (ar) with a 80th percentile value of 0,05

mg/MJ (ar) is designated as: “Class code NCV 3; Cl 2; Hg 2”.

EN15359 IS NOT THE END OF WASTE

On EU level several steps are now taken to develop end-of-waste

criteria for specific categories of waste according to article 6 of

the Waste Framework Directive. A certain waste

may only cease to be a waste if:

the substance is commonly used for specific purposes,

a market or demand must exist,

the substance fulfills the technical requirements for the

specific purposes and meets the existing legislation and

standards applicable to products,

use of the substance will not lead to overall adverse

environmental or human health impact.

CONCEPT OF END OF WASTE

The revised Waste Framework Directive (WFD) includes a

provision by which certain specified waste shall cease to be

waste when it has undergone a recovery operation and

complies with specific criteria developed in accordance with

a number of conditions.

The criteria shall include limit values for pollutants where

necessary and shall take into account any possible adverse

environmental effects of the substance or object.’

MSW AND RDF

Municipal

Solid Waste

RDF Pellets

THERMAL PARAMETERS OF WASTE

Municipal Solid Waste MSW

LHV average Wd=8,66 MJ/kg

max Wd=9,94 MJ/kg

min Wd=6,82 MJ/kg

Humidity average w = 36,99 %

Sewage sludge

LCV average Wd=0,71 MJ/kg

max Wd=5,75 MJ/kg

min Wd= - 2,13 MJ/kg

Water content average w = 78,07%

Dry mass ms = 21,93 %

Three axis diagram (tanner )

0 10 20 30 40 50 60 70 8 0 90 1000 10 20 30 40 50 60 70 80 90 100

0

10

20

30

40

50

60

70

80

90

1000

10

20

30

40

50

60

70

80

90

100

Organic fraction, %

CHANGES OF LHV OF MSW AFTER SEGREGATION

Segregation of balast material (mineral) from MSW

increases NCV to 10,46 MJ/kg.

Reduction of biofraction (recycling and recovery) after

year 2020 by 50% reduces NCV by 29%

CHANGE OF THE AMOUNT OF MSW AFTER

SEGREGATION

24/45

220 000 Mg/y

220 000 Mg/y

182 160 Mg/y

175 164 Mg/y

Wariants Amount of raw

waste Mg/y

Waste to the

boiler Mg/y

LCV MJ/kg Amount of energy

GJ/y

Waste as

received

220 000 220 000 8,66 1 905 200

After segregation

of inert materials

220 000 182 160 10,46 1 905 200

After segregation

of paper and

plastics

220 000 175 164 7,37 1 290 958

TECHNOLOGY OF PRODUCTION OF

FUELS FROM WASTE

TYPES OF SOLID FUEL FROM WASTE

BRAM - Brennstoff aus Muell,

SRF - Solid Recovered Fuel from MSW.

RDF – Residue Derived Fuel.

BRAP – Brennstoff aus Papier.

Fuel from tyres.

PAKOM – communal fuel.

CROSS-SECTION OF TYPICAL RDF SYSTEM

RDF TECHNOLOGY

RDF FROM PROCESSED MUNICIPAL SOLID

WASTE

Refuse derived fuel (RDF) can be produced from municipal solid

waste (MSW) by:

• Separation at source;

• Sorting or mechanical separation;

• Size reduction (shredding, chipping and milling);

• Separation and screening;

• Blending;

• Drying and pelletising;

• Packaging; and

• Storage.

REFUSE DERIVED FUEL TECHNOLOGY

Solid refuse derived fuel

PARAMETERS OF RDF (PAKOM)

UTILIZATION OF RDF FROM MSW

The following options for the utilization and conversion of RDF

from MSW to energy have been used or could be used in the

future:

on-site in an integrated thermal conversion device, which

could include grate or fluidized bed combustion,

gasification or pyrolysis;

off-site at a remote facility employing grate or fluidized

bed combustion, gasification or pyrolysis;

co-combustion in coal fired boilers;

co-incineration in cement kilns;

co-gasification with coal or biomass.

Application of fuel from waste

Additional fuel in waste and sludge incineration plants.

As additional fuel in power stations: electropower stations,

central heating stations.

As alternative fuels in industrial furnace and boilers (cement

industry, steel industry, paper and food processing etc.)

As base fuel in dedicated burners and combustion

chambers.

Parameter Unit MSWSludge

(dry)ORFA

LHV MJ/kg 3 – 8 7 – 15 18

Moisture % 20 – 49 - 5 – 8

Ash % 25 – 37 20 – 40 15,7

Combustible % 23 – 38 50 – 55 60 – 70

Ultimate analysis

C % 11 – 24 28 – 35 39 – 44

H % 1,5 – 4,2 4 – 5,5 6,3

N % 0,02 – 0,7 3,5 – 5,5 0,4

S % 0,05 – 0,1 1 – 1,5 0,15 – 0,22

Cl % 0,08 – 0,4 0,03 – 0,08 0,04 – 0,06

O % 10 – 13,6 11 – 16,5 20 – 28

Heavy metals

Zn ppm 6632400 –

6100286

Cu ppm 45 80 – 800 248

Ni ppm 3 16 – 50 10,8

Cd ppm 5,95 1,4 – 20 1,5

Pb ppm 279 20 – 50 58

Hg ppm 1,22 2 – 2,5 0,11

Parameters of municipal

waste, sewage sludge

and fuel from waste

(ORFA)

RDF composition - examples

MASS BALANCES OF THREE COMPONENTS OF FUEL

39/45

unit waste sludge 70% w.+30% sl 90% w.+10%sl.

Humidity % 36,14 78,07 48,72 40,33

Mineral matter %w 17,65 9,73 15,27 16,86

Organic matter %w 46,21 12,2 36,01 42,81

Tanner’s diagram

COMPOSITION AND PARAMETERS OF SOME PLASTICS AND

FUELS

Polymer

LHV

MJ/kg

Ultimate analysis [% mass]

c h other

Polyethylene 43 85,6 14,4 -

Polypropylene 44 85,6 14,4 -

Polystyrene 40 92,3 7,7 -

Polythereftalan ethylene 31 74,9 5,0 o-20,0

Polyvinyl chloride PVC 18 38,4 4,8 cl-56,8

Polyacetylene 45 92,3 7,7 -

Wood ab.18 50,0** 6,0* o-44,0**

Coal 26 80-85 4-6 o, s, n

** average values

* Dry ash free,

WASTE USED AS FUEL IN CEMENT KILNS

Combustible fractions of MSW,

Liquid waste of refinery indystry,

Used car and lorry tyres,

Overdue fertilizers and herbicides,

Overdue and out of date medicine and pharmaceutical products,

Old paints and solvents,

Waste from coal enrichment process.

Cement industry - requirements

Parameter Limit Unit

LHV > 14 MJ/kg weekly av.

> 11,7 MJ/kg daily av.

Cl < 0,2 %

S < 2,5 %

PCB < 50 ppm

Heavy metals sum. < 2500 ppm

Incl. Hg < 10 ppm

Cd + Tl < 100 ppm

PARAMETERS OF BRIQUETTES MADE FROM

WOOD WASTE

Parameter Value

Humidity 6,40 %

Ash 0,50 %

Sulphur 0,01 %

Hydrogen 5,20 %

HHV 19,8 MJ/kg

LHV 18,54 MJ/kg

PARAMETERS OF PLASTIC FRACTIONS

Polymer LHV

MJ/kg

Elements [ % mass.]

c h other

Polyetylene 43 85,6 14,4 -

Polypropylene 44 85,6 14,4 -

Polystyrene 40 92,3 7,7 -

Poly(ethylene

terephthalate) PET

31 74,9 5,0 o-20,0

Polyvinyl chloride 18 38,4 4,8 cl-56,8

Polyacetylene 45 92,3 7,7 -

Wood ok.18 50,0** 6,0* o-44,0**

Coal 32 80-85 4-6 o, s, n

** medium

* daf,

Oil from tyre pyrolysis

The pyrolysis process is the thermal degradation of waste in

the absence of oxygen at elevated temperatures and

pressures. The process is carried out at temperatures

typically upwards of 430°C. In practice, it is not possible to

achieve a completely oxygen-free enviroment and so a

small amount of oxidation occurs. The products of pyrolysis

(from organic waste) are gases, small quantities of liquid,

and a solid residue containing carbon and ash. The gases

produced in the process can then be used to provide the

heating energy for continuing the process.

This pyrolysis oil can then be used as a replacement diesel fuel.

PARAMETERS OF RUBBER FRACTION OF MSW

Name Elements % Water Combu

stible

Ash LHV

c h o n s % % % MJ/kg

Rubber ar 65,0 5,0 12,6 0,2 0,6 5,0 48,0 11,6 25,79

Rubber daf 7,9 6,0 15,1 0,3 0,7 - - - 31,06