SIST-TP CEN/TR 15677:2008

Fly ash obtained from co-combustion - A report on the situation in Europe

This CEN report compiles the experience collected from the co-combustion of biomass and waste by 2002. The data and the test results are given from systematic research projects and from investigations on fly ash obtained from co-combustion in different power plants in the framework of national certification processes or from other co-combustion tests. The report:
   includes the existing national regulations for the demonstration of the suitability of fly ash from co-combustion,
   gives a survey on the combustion materials used so far,
   describes the chemical composition of fly ashes obtained from co-combustion,
   lists the chemical and physical properties of the fly ashes, which are relevant to the technical and environmental properties of concrete,
   includes test results of properties of concrete with fly ashes obtained from co-combustion.

Flugasche, die unter Verwendung eines Anteils an Mitverbrennungsstoffen versorgt wird - Sachstandsbericht über die europäische Situation

Cendres volantes obtenues par co-combustion - Rapport sur la situation en Europe

Le présent rapport CEN compile l'expérience rassemblée a partir de la co-combustion de la biomasse et des déchets autour de 2002. Les caractéristiques et les résultats d'essai donnés proviennent de projets de recherche systématiques et d'investigations sur des cendres volantes obtenues par co-combustion dans différentes centrales de production d’électricité dans le cadre des processus de certification nationale ou d'autres essais de co-combustion. Le rapport :
   inclut les reglements nationaux existants pour la démonstration de l'aptitude des cendres volantes obtenues par co-combustion,
   donne un aperçu sur les matériaux de combustion utilisés jusqu'ici,
   décrit la composition chimique des cendres volantes obtenues par co-combustion,
   énumere les propriétés chimiques et physiques des cendres volantes, qui sont pertinentes aux propriétés techniques et environnementales du béton,
   inclut des résultats d'essai relatifs aux propriétés du béton avec des cendres volantes obtenues par co-combustion.

Elektrofiltrski pepel, pridobljen pri soizgorevanju - Poročilo o stanju v Evropi

General Information

• Status: Published
• Publication Date: 31-Jul-2008
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: BBB - Concrete, reinforced concrete and prestressed concrete
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-May-2008
• Due Date: 04-Aug-2008
• Completion Date: 01-Aug-2008
• Directive: 89/106/EEC - Construction products
• Ref Project: CEN/TR 15677:2008 - Fly ash obtained from co-combustion - A report on the situation in Europe

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN/TR 15677:2008
01-september-2008
(OHNWURILOWUVNLSHSHOSULGREOMHQSULVRL]JRUHYDQMX3RURþLORRVWDQMXY(YURSL
Fly ash obtained from co-combustion - A report on the situation in Europe
Flugasche, die unter Verwendung eines Anteils an Mitverbrennungsstoffen versorgt wird
- Sachstandsbericht über die europäische Situation
Cendres volantes obtenues par co-combustion - Rapport sur la situation en Europe
Ta slovenski standard je istoveten z: CEN/TR 15677:2008
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
SIST-TP CEN/TR 15677:2008 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 15677:2008

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SIST-TP CEN/TR 15677:2008
TECHNICAL REPORT
CEN/TR 15677
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
May 2008
ICS 91.100.30

English Version
Fly ash obtained from co-combustion - A report on the situation
in Europe
Cendres volantes obtenues par co-combustion - Rapport Flugasche, die unter Verwendung eines Anteils an
sur la situation en Europe Mitvergrennungsstoffen gewonnen wird -
Sachstandsbericht über die europäische Situation
This Technical Report was approved by CEN on 25 September 2007. It has been drawn up by the Technical Committee CEN/TC 104.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15677:2008: E
worldwide for CEN national Members.

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Contents Page
Foreword.4
Introduction .5
1 Scope.7
2 National regulations.7
2.1 General.7
2.2 Terms and definitions .7
2.3 Experience in different countries.8
2.3.1 The Netherlands.8
2.3.2 Germany.8
2.3.3 Denmark.8
2.3.4 United Kingdom.9
2.3.5 Finland.9
2.3.6 Belgium.9
2.3.7 Other countries.9
2.3.8 Overview of requirements.9
3 Inventory of co-combustion materials .11
4 Properties of fly ash obtained from co-combustion — Test results .16
4.1 General.16
4.2 Chemical properties.16
4.2.1 General.16
4.2.2 Sewage sludge.16
4.2.3 Biomass.16
4.2.4 Petcoke.17
4.2.5 Paper sludge.17
4.2.6 Straw.17
4.2.7 Wood.17
4.2.8 Meat and Bone meal .17
4.2.9 Other co-combustion materials.17
4.3 Physical and chemical properties of fly ash.29
4.4 Environmental compatibility.32
4.4.1 General.32
4.4.2 Netherlands.32
4.4.3 Germany.32
4.5 Compressive strength and activity index of mortar samples according to EN 450 .34
4.5.1 General.34
4.5.2 Netherlands.34
4.5.3 Germany.36
4.5.4 Finland.38
4.5.5 Belgium.39
5 Properties of concrete with fly ash obtained from co-combustion.39
5.1 Concepts in Europe — General.39
5.2 Conformity tests on fresh and hardened concrete in the Netherlands (technical
properties) .40
5.2.1 General.40
5.2.2 Assessment criteria on technical concrete properties according to CUR 70 .40
5.2.3 Test results — Overview .41
5.2.4 Durability of concrete.42
5.2.5 Admixtures in concrete.43
5.2.6 Air-entraining agent.44
5.2.7 Retarding agents.44
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5.3 Tests results on fresh and hardened concrete properties from trials in Finland (technical
properties).45
5.4 Assessment of the environmental compatibility of fly ash obtained from co-combustion
(leaching tests on concrete).46
5.4.1 Netherlands.46
5.4.2 Germany.47
Annex A (informative) .50
Bibliography.51

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Foreword
This document (CEN/TR 15677:2008) has been prepared by Technical Committee CEN/TC 104 “Concrete
and related products”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

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Introduction
The test results included in this report demonstrate, with certain exceptions, that the properties of fly ashes
obtained from the co-combustion of biomass and waste used at this time, do not significantly differ from fly
ashes obtained from the combustion of pure coal. In some cases, changes in the chemical composition of fly
ash occur, which may be of technical relevance to concrete. These changes have to be taken into account.
Examples are:
 higher content of alkalis in fly ash from the co-combustion of straw;
 increase of P O in case of the co-combustion of sewage sludge;
2 5
 increase of vanadium and nickel content in fly ash obtained from the co-combustion of petcoke.
The requirements of the EN 450:1994 regarding harmlessness and the effects of fly ashes in concrete are met.
In some cases the maximum amount of combustion materials added to the coal is limited by the requirements
of EN 450.
Investigations on concrete with fly ashes from co-combustion did not show any significant change in concrete
properties. This applies to properties of fresh concrete, to the efficiency of admixtures like air entraining
agents and retarders, as well as to properties of hardened concrete like strength development and ingression
of chloride ions into the concrete. In general, tests on the leaching of concrete with fly ash from co-combustion
did also not deviate from concrete with fly ashes from pure coal. Merely in the case of co-combustion of
petcoke an increase in the leaching of vanadium was found. In this case a limitation of the amount of petcoke
added to the coal may be required.
Fly ashes obtained from the combustion of coal have been used as a valuable concrete constituent for more
than 30 years in Europe. At the beginning, utilisation was based on national standards in Member States. The
European standard EN 450 was first published in 1994 and according to this standard fly ash for concrete is
defined as follows:
“Fine powder of mainly spherical, glassy particles, derived from burning of pulverized coal, which has
pozzolanic properties and consists essentially of SiO and Al O , the content of reactive SiO , defined
2 2 3 2
and determined as described in ENV 197-1, being at least 25 % by mass.
Fly ash is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases of
furnaces fired with pulverised anthracite or bituminous coal.”
Since the beginning of the nineties coal-fired power plants started to burn co-combustion materials such as
biomass and waste. As an example, sewage sludge was offered to power plant operators for co-combustion in
order to get rid of the material. Power plants made it possible to remove animal meal at low costs when the
production of animal food from animal meal was no longer permitted. In addition, biomass is used more and
more for co-combustion in order to reduce emissions of CO from the combustion of fossil fuels. In some
2
countries power generators have been committed by their governments to co-combust biomass in order to
meet Kyoto targets.
This development was taken into account when the revision of EN 450 began in 1998. Fly ash obtained from
co-combustion was included in the scope of the standard by extending the definition mentioned above:
“Fine powder of mainly spherical, glassy particles, derived from burning of pulverized coal, with or
without co-combustion materials, which has pozzolanic properties and consists essentially of SiO and
2
Al O , the content of reactive SiO as defined and described in EN 197-1 being at least 25 % by mass.
2 3 2
Fly ash is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases of
furnaces fired with pulverised coal, with or without co-combustion materials, see clause 4.
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Fly ash may be processed, for example by the classification, selection, sieving, drying, blending, grinding
or carbon reduction, or by combination of these processes, in adequate production plants. Such
processed fly ash may consist of fly ashes from different sources, each conforming to the definition given
in this clause. If one or more of incoming fly ashes are obtained from co-combustion, then the processed
fly ash shall be considered as fly ash from co-combustion.
NOTE Municipal and industrial waste incineration ashes do not conform to the definition given in this clause.”
A general principle kept in this standard is that properties of fly ash regarding their effects on, and their
contribution to concrete properties may not be changed due to co-combustion. This has to be proven by
suitability tests and current quality control. In addition, the environmental compatibility of concrete with fly
ashes has to be demonstrated.
The data presented in this report were collected by an enquiry, which was launched by CEN/TC 104/WG 4 in
January 1998. The information received was supplemented by test results obtained from additional
investigations.
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1 Scope
This CEN report compiles the experience collected from the co-combustion of biomass and waste by 2002.
The data and the test results are given from systematic research projects and from investigations on fly ash
obtained from co-combustion in different power plants in the framework of national certification processes or
from other co-combustion tests. The report:
 includes the existing national regulations for the demonstration of the suitability of fly ash from co-
combustion,
 gives a survey on the combustion materials used so far,
 describes the chemical composition of fly ashes obtained from co-combustion,
 lists the chemical and physical properties of the fly ashes, which are relevant to the technical and
environmental properties of concrete,
 includes test results of properties of concrete with fly ashes obtained from co-combustion.
2 National regulations
2.1 General
In most countries of the EC the non-harmonized product standard EN 450:1994-09 entitled “Fly ash for
concrete — Definitions, requirements and quality control” is used. The basic experience with EN 450 is very
positive.
In the course of environmental regulations, power station operators are forced more and more to fire co-
combustion materials alongside the usual hard coal. Some countries of the EU already gained experiences
with the co-combustion of high calorific materials and transferred these into appropriate national sets of rules.
Information concerning these rules is to be reported in the following after giving some essential definitions.
2.2 Terms and definitions
For the purposes of this CEN Report, the following terms and definitions apply.
2.2.1
fly ash
fly ash is a fine powder of mainly spherical, glassy particles, derived from burning pulverized coal, which has
pozzolanic properties and consists essentially of SiO and Al O , the content of reactive SiO defined and
2 2 3 2
determined as described in ENV 197-1, being at least 25 % by mass; fly ash is obtained by electrostatic or the
mechanical precipitation of dust-like particles from flue gases or furnaces fired with pulverized anthracite or
bituminous coal
[EN 450:1994-09]
2.2.2
fly ash obtained from co-combustion
fly ash that is generated from firing pulverised coal, to which a certain amount of co-combustion material has
been added
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2.3 Experience in different countries
2.3.1 The Netherlands
To show whether the quality of fly ash is affected by co-combustion, a broad research program was performed
in which both the technical quality and the environmental compatibility of concrete with fly ash obtained from
co-combustion was evaluated in comparison with the quality of concrete with reference fly ash (obtained from
firing pure coal). In this research program fly ash from co-combustion of demolition wood, sewage sludge,
paper sludge and petcoke was evaluated. As a result of this broad research program, a conformity procedure
was developed by which fly ash obtained from co-combustion can be checked as to whether it conforms to
EN 450. This procedure consists of the tests according to EN 450, extended with a “conformity analysis (see
Table 1 through Table 3), in which the effects of the fly ash from co-combustion on durability and on the action
of concrete admixtures are established. This procedure has been made part of the Dutch technical standards
(CUR 1999, chapter 7).
2.3.2 Germany
Increasing problems with the deposition of municipal sewage sludge led, in the beginning of the nineties, to an
increasing co-combustion in German power plants. Under normal operation conditions trials with the co-
combustion of municipal sewage sludge have been carried out in several German power plants with the aim to
investigate the influence of co-combustion on the physical, chemical and environmentally relevant properties
of fly ash. Based on these investigations, a regulation for the production of DIN EN 450 fly ash from the
combustion of pulverised coal (anthracite or bituminous) and up to a maximum of 5 % by mass of municipal
sewage sludge in relation to the dry coal was added in the attachment 1.6 of the German “Construction
products list A (CPL A)” (Bauregelliste A) in 1996.
If the DIN EN 450 requirements and the provisions concerning the maximum amount of sewage sludge and
the limit values on trace elements and phosphate in Table 1 are fulfilled, the fly ash produced may be used in
reinforced and pre-stressed concrete (pre-tensioned and post-tensioned) according to DIN 1045 and
DIN 4227 without any limitations and further quality control measures.
Recently new trials have been launched in some German power plants to assess the influence of the co-
combustion of petroleum coke (petcoke) on the physical, chemical and environmentally relevant properties of
fly ash. In the framework of technical approval, the maximum amount for the co-combustion of petcoke is
limited to that amount which is investigated and proved in the approval procedure. A guideline assessing of
the impact of building products on soil and groundwater was set into force by the building authorities
(Deutsches Institut für Bautechnik) in 2001. The guidelines describe a procedure for initial testing and give
requirements with respect to environmental properties of building materials in the course of the application for
national technical approval. The assessment is based on the report of certain trace elements and organic
constituents as well as on the leaching of materials, which are harmful to soils and groundwater. In case of
cementitious materials like fly ash used as an addition to concrete the leaching from a fly ash concrete as
measured in a stand test is compared to limiting values derived from requirements on groundwater quality by
using a distribution model. As a result of the assessment procedure fly ashes obtained from co-combustion in
certain power plants have got a technical approval. The technical approval restricts the maximum amount of
co-combusted petcoke to 10 % by mass related to the coal and limits the content of nickel and vanadium in
the fly ash to 600 mg/kg and 1 500 mg/kg respectively.
Beyond the use of municipal sewage sludge and petcoke as co-combustion materials, tests on fly ash
obtained from the co-combustion of bone meal and paper sludge are also on going at present (as of January
2002) in Germany.
2.3.3 Denmark
In Denmark only fly ashes according to EN 450 are allowed to be used as a concrete addition. Co-combustion
was performed in some trials with straw but until now it is not introduced in national regulations.
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2.3.4 United Kingdom
In the UK a trial test series on the co-combustion of petcoke was performed in 1997 to evaluate and the
environmental effects of burning blends of petcoke and coal. The results confirm, that there was no impact on
the environment in burning petcoke blends.
In the UK mostly environmental criteria are set for the allowance of co-combustion as before proceeding with
co-combusting any material, one has to obtain approval from the Environment Agency and Health & Safety
Executive. Then a joint assessment of the possible emissions from the power plant, the disposal or utilisation
of the fly ash, the risk of contamination from the raw co-combustion material, etc. is assessed. The
Environment Agency has the right to prevent any co-combustion from occurring unless they are satisfied with
the safety procedures, emissions, disposal of fly ash, etc.
If concrete with fly ash obtained from co-combustion should be applied in contact with drinking water, the
situation is different. For materials in contact with drinking water the Drinking Water Inspectorate (DWI) is
responsible. Currently concrete within the UK is a blanket approval for use in contact with drinking water (as it
is the only material which achieves this). For concrete with fly ash obtained from co-combustion, this approval
may not apply and leaching tests may have to be carried out to the satisfaction of the DWI.
2.3.5 Finland
Only limited trial test series on the co-combustion of wood are available and at this time this has not lead to
regulations on a national scale. The results, however, generally confirm the findings of the investigations
carried out in other countries.
2.3.6 Belgium
In Belgium the reuse of fly ash from co-combustion is regulated by the standard that deals with the reuse of
waste material as secondary building material called “Vlarea”. According to this standard, fly ash obtained
from co-combustion has to meet requirements regarding the total composition and the leaching of heavy
metals.
2.3.7 Other countries
Requirements for co-combustion materials were reported from Italy. There was no response to the inquiry
From the other countries, thus information and data for these countries are not available.
2.3.8 Overview of requirements
In Table 1 and Table 2 an overview is given for the requirements for co-combustion materials and fly ash
obtained from co-combustion.
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Table 1 — Requirements for materials allowed to be used as co-combustion material in different
European countries
a
Country — NL DE Be DK I
Residues
Property/
Co-com- Munici-
from coal
parameter Sewage Sewage Sewage Paper
bustion unit  Straw and coke pal
sludge sludge sludge sludge
from steel
material waste
c
industry
Reference
— — [10] [12] [22] [14] [13]
require
Parameter — —
ment
calorific value
KJ/kg — — 16 000 15 000 8 560 1 200
(LL)
General
properties humidity (UL) % — — 8/6 25 20 30
ash content (UL) %  — — 20 — 10
Chloride % — — — 0,9 0,9
Element
Cl (organic) mg/kg — — — 1
content
Sulfur % — — 2/1,5 0,6 0,6 0,5
(UL)
b
P O
% 25 — — — —
2 5
Arsenic — 250 — 9 9 9
Cadmium 10 10 —
—
Chromium 900 1 250 — 100 100 50
—
Copper 800 375 — — — 300
Copper (soluble) —  — 300 300 —
Heavy
Mercury 8 5 — — — —
mg/kg
metal con-
Mangane — dry  — 400 400 150
tent (UL)
matter
Nickel 200 250 — 40 40 20
Lead 900 1 250 — — — 200
Lead (volatile) —  — 200 200 —
Zink 2 500 1 250 — — — —
Cd+Hg — — — 7 7 7
Vanadium — — — — — —
LL: lower limit.
UL: upper limit.
a
In the Netherlands the requirements are based on the framework of emission limits and limits of hazardous wastes and part of the
permits for co-combustion. The Dutch power plants analyse the co-combustion streams and reject their policy for the choice of co-
combustion materials on the quality of the by-products.
b
Related to the ash of the sewage sludge.
c
During the technical process of steel production coal and coke is combusted; from this combustion residues occur.

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Table 2 — Technical requirements for fly ash from co-combustion
according to EN 450
Reference EN 450
LOI
≤ 5
% by mass
Cl
≤ 0,10
% by mass
SO
3
≤ 3,0
% by mass
Free CaO
≤ 1,0
% by mass
Fineness
≤ 40
% by mass
Activity index ≥ 75 at 28 d
% ≥ 85 at 91 d
Soundness
≤10
mm

3 Inventory of co-combustion materials
The co-combustion materials included in EN 450-1:2005 are divided into six main groups:
 Vegetable material like wood chips, straw, olive shells and other vegetable fibres;
 Green wood and cultivated biomass;
 Animal meal;
 Municipal sewage sludge;
 Paper sludge;
 Petroleum coke;
 Virtually ash free liquid fuels and gaseous fuels.
In Table 3 an overview is given on co-combustion materials, which have been co-combusted in European
countries. The chemical and physical composition of different co-combustion materials are summarised in
Table 4a through Table 4c,.
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Table 3 — Materials that have been used for co-combustion in different countries of Europe
Origin of Amount
Power Co-combustion
Country No. Date
a b
Plant material
coal % by mass
I HW-8 blend sewage sludge 3, 6 1995
II AC-8 blend paper sludge 5, 8 1995-12
c
III AC-9 blend 5, 10 1995
petcoke A and B
IV AC-9 blend petcoke A and B 5, 10 1996
V CG-13 blend demolition wood 6, 12 1997-3
hydrocarbon gas
VI BS12 blend 3, 6*) 1997
(phosphorus production)
VII MV-2 blend biomass pellets 5 1997
VIII AC-9 blend paper sludge 5 1998-3
NL
IX MV-2 blend biomass/citrus pellets 8,5 1998-9
X BS-12 Poland sewage sludge 5, 10 1998-10
XI BS-12 blend paper sludge 5 1998-12
XII MV1 blend biomass pellets 8 1999-05
XIII MV-1 blend meat and bone meal 1,6 1999-08
XIV MV1 blend coffee grounds 3 1999-09
XV BS-12 blend cacao shells 9 1999-11
XVI MV1 blend poultry dung 3 1999-11
XVII MV1 blend meat and bone meal 2,7 2001-04
A sewage sludge 1,0 t
...