SIST-TP CEN/TR 16788:2015

SLOVENSKI STANDARD
SIST-TP CEN/TR 16788:2015
01-marec-2015
1DGRPHãþD
SIST-TP CEN/TR 13767:2005
Karakterizacija blata - Smernica za dobro prakso toplotnih procesov
Characterization of sludges - Guideline of good practice for thermal processes
Charakterisierung von Schlämmen - Anleitung für die gute fachliche Praxis thermischer
Prozesse
Caractérisation des boues - Lignes directrices relatives aux bonnes pratiques pour les
procédés thermiques
Ta slovenski standard je istoveten z: CEN/TR 16788:2014
ICS:
13.030.20 7HNRþLRGSDGNL%ODWR Liquid wastes. Sludge
SIST-TP CEN/TR 16788:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 16788:2015

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SIST-TP CEN/TR 16788:2015

TECHNICAL REPORT
CEN/TR 16788

RAPPORT TECHNIQUE

TECHNISCHER BERICHT
November 2014
ICS 13.030.20 Supersedes CEN/TR 13767:2004, CEN/TR 13768:2004
English Version
Characterization of sludges - Guideline of good practice for
thermal processes
Caractérisation des boues - Lignes directrices relatives aux Charakterisierung von Schlämmen - Anleitung für die gute
bonnes pratiques pour les procédés thermiques fachliche Praxis thermischer Prozesse


This Technical Report was approved by CEN on 25 November 2014. It has been drawn up by the Technical Committee CEN/TC 308.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16788:2014 E
worldwide for CEN national Members.

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Contents Page
Foreword .4
Introduction .5
1 Scope .8
2 Normative references .8
3 Terms and definitions .8
4 Abbreviations .9
5 Regulatory aspects . 10
6 Sludge properties . 11
6.1 General . 11
6.2 Physico-chemical characteristics . 11
6.2.1 General . 11
6.2.2 Dry matter . 11
6.2.3 Loss on ignition . 12
6.2.4 Calorific value . 12
6.2.5 Grease, scum and screening . 13
6.2.6 Physical consistency and others . 13
6.3 Chemical characteristics . 13
6.3.1 General . 13
6.3.2 Sulphur . 14
6.3.3 Phosphorus . 14
6.3.4 Nitrogen . 14
6.3.5 Chlorine and other halogen . 14
6.3.6 Organic micro pollutants . 14
6.3.7 Trace elements . 15
7 Thermal processes fundamentals. 15
7.1 Incineration . 15
7.2 Gasification . 16
7.3 Pyrolysis . 17
7.4 Wet (air) oxidation. 17
7.5 Others . 18
8 Equipment . 18
8.1 Incineration devices . 18
8.1.1 General . 18
8.1.2 Fluidized Bed Furnace (FBF) . 20
8.1.3 Multiple Hearth Furnace (MHF) . 22
8.1.4 Combination of FBF and MHF . 22
8.1.5 Others . 22
8.2 Gasification devices . 23
8.3 Pyrolysis Devices . 25
8.4 Wet air oxidation devices . 26
8.5 Design aspects . 26
8.6 Auxiliary equipment . 27
8.6.1 General . 27
8.6.2 Transport, receiving area, storage and feeding systems . 27
8.6.3 Heat recovery . 27
8.6.4 Flue gas cleaning . 28
8.6.5 Ash and other residue handling . 28
8.6.6 Wastewater treatment . 28
8.6.7 Process monitoring . 29
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9 Operational aspects . 29
9.1 General . 29
9.2 Incineration . 30
9.2.1 General . 30
9.2.2 Fluidized Bed Furnace (FBF) . 30
9.2.3 Multiple Hearth Furnace (MHF) . 32
9.3 Technologies without operational background in sewage sludge: Gasification/ Pyrolysis . 33
9.3.1 General . 33
9.3.2 Hazards . 33
10 Management of energy and material products. 33
10.1 General . 33
10.2 Incineration . 33
10.3 Gasification / Pyrolysis . 35
10.4 Resume 10.1 through 10.3 . 37
10.5 Wet Oxidation . 37
11 Management of residues . 37
11.1 General . 37
11.2 Flue Gas. 37
11.2.1 Composition/parameters . 37
11.2.2 Equipment . 39
11.3 Ashes . 42
11.3.1 Composition/Parameters . 42
11.3.2 Equipment . 42
11.4 Wastewater . 42
12 Economic aspects . 43
13 Co-management with other organic wastes . 43
13.1 General . 43
13.2 Specific considerations . 44
13.3 Additional storage and transports aspects . 49
13.3.1 General . 49
13.3.2 Storage . 49
13.3.3 Transport . 50
14 Assessment of impacts . 50
14.1 General . 50
14.2 Environmental aspects . 51
14.3 Economic aspects . 51
14.4 Social aspects . 51
Annex A (informative) Emission limit values . 53
Annex B (normative) Calorific Value calculations . 55
Annex C (informative) Tables. 57
Annex D (normative) Various systems to input sludge into a household waste incineration plant . 59
D.1 General . 59
D.2 Sludge whose dry matter content < 35 % . 59
D.3 Sludge whose dryness is > 65 % . 59
D.4 Sludge whose dry matter content between 35 % to 65 % . 60
D.5 Drying the sludge in the household waste incineration plant . 60
Bibliography . 61

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Foreword
This document (CEN/TR 16788:2014) has been prepared by Technical Committee CEN/TC 308
“Characterization of sludge”, the secretariat of which is held by AFNOR.
This document supersedes CEN/TR 13767:2004 and CEN/TR 13768:2004.

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Introduction
It is recognized that wastewater sludge is a potential source of valuable resources. Material recycling is higher
in the waste hierarchy (ref. 2008/98/EC Directive) than recovery (energy and material). Sludge incineration
and other organic matter treatments by thermal processes (gasification, pyrolysis and wet oxidation) should
deal with materials which do not meet beneficial use requirements. They represent a consistent year round
solution. To decide which type of solution is appropriate for a particular sludge, Figure 1 should be consulted.
Thermal processes involve, among others, reduction of volume and weight, highest destruction of toxic
organic compounds, possible recovery of phosphorus and other useful materials. Drawbacks include high
costs and complexity of plant operation.
In all cases, the energy balance (including energy for removing water etc.) and carbon footprint of the
processes should be calculated to verify the environmental benefit of the process.
A good performance of a thermal processing plant also depends upon the provision of proper auxiliary
equipment and devices, which include receiving and storage systems, pre-treatments equipment, feeding
system, flue gas cleaning, heat recovery, ash handling, wastewater disposal and process monitoring.
The purpose of this Technical Report is to describe good practice for sludge incineration and other organic
matter treatments by thermal processes in order to ensure a safe and economical operation. The main goals
are to:
— describe the principal design parameters relevant to different process schemes;
— assess the operating procedures able to perform optimal energy balance, emissions control and
equipment durability;
— provide the responsible authorities with well-established and easily applicable protocols for control
purposes;
— promote the diffusion of good practice;
— contribute to taking appropriate decisions.
Priority should be given to reduction of pollutants at the origin and to recover, if technically and economically
feasible, valuable substances (e.g. phosphorus) from sludge and derived products.
As part of a process and company quality approach, the relevant issues are therefore:
— exploiting the operating data and the statutory inspections carried out;
— rendering the process reliable, optimizing and of perpetuating it, as well as guaranteeing a permanent
development;
— maintaining a climate of confidence between the authorities, the sludge producers, the transporters, the
incineration plant and waste disposal site operators and allowing the services to be provided on a
contractual basis.
The local considerations to be taken into account are:
— the adoption of a more convenient solution with respect to other options;
— the geographical context, the client population and therefore the potential input material as well as the
expected developments;
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— the proximity of the sewage treatment plant and the local transportation network;
— the capacity of treatment plants.
All of the recommendations of this document constitute a framework within which the thermal processes can
be proposed in addition to and/or as a substitution for land utilization, landfilling when allowed, or any other
process when relevant situations occur and appropriate conditions are met.
The management of sludges both upstream and downstream of the treatment process to ensure that it is
suitable for the outlets available is outlined in CEN/TS 13714:2013.
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Figure 1 ― A basic scheme for deciding on sewage sludge use/disposal options and the relevant
CEN/TC 308 guidance documents
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1 Scope
This Technical Report describes good practice for the incineration and other organic matter treatment by
thermal processes of sludges.
Thermal drying, thermal conditioning and thermal hydrolysis are excluded.
This Technical Report is applicable for sludges described in the scope of CEN/TC 308 specifically derived
from:
— storm water handling;
— night soil;
— urban wastewater collecting systems;
— urban wastewater treatment plants;
— treating industrial wastewater similar to urban wastewater (as defined in Directive 91/271/EEC);
but excluding hazardous sludges from industry.
2 Normative references
Not applicable.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
thermal treatment
reduction of organic matter by incineration, gasification, pyrolysis and wet air oxidation
3.2
thermal process
technique for the application of thermal treatment
3.3
combined thermal treatment
thermal treatment of sludge and other waste in the same device
3.4
pyrolysis
thermal treatment without supply of oxygen
3.5
gasification
thermal treatment with less than the stoichiometric supply of oxygen or air (partial combustion)
3.6
furnace
enclosed chamber where combustion of organic matter takes place
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3.7
boiler
specific part of the thermal treatment plant where heat exchange takes place in view of recovering heat and
energy
3.8
flue gas treatment
any physical or chemical process aimed at cleaning the gas emission resulting from the thermal treatment with
the regard to their discharge into the atmosphere
3.9
bottom ash
combustion residue collected at the bottom of combustion furnaces
3.10
fly ash
solid material that is entrained in a flue gas stream
3.11
energy recovery
activity to use combustible waste as a means to generate energy through thermal treatment with recovery of
heat
3.12
recycling
activity in a production process to process waste materials for the original purpose or for other purposes,
excluding energy recovery
3.13
slag
partially glassy by-product obtained by cooling a mineral liquid phase
3.14
energy efficiency
amount of energy and/or heat recovery in relation to the energy content of input material
3.15
wet air oxidation
aqueous-phase oxidation of organics under pressure, using either air or oxygen as the oxidant
3.16
syngas
mixture of gases (including carbon monoxide, hydrogen, methane, etc.) produced from gasification or
pyrolysis process
3.17
char
combination of non-combustible materials and carbon produced from devolatization, gasification or pyrolysis
process
3.18
combustion
chemical and exothermical reaction with full oxidation of combustible materials
4 Abbreviations
For the purposes of this document, the following abbreviations apply.
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BAT Best Available Techniques
COD Chemical oxygen demand
DM Dry Matter
ELV Emission Limit Values
GCV Greater (or gross) Calorific Value
HTFB High Temperature Fluidized Bed
LCV Lower (or net) Calorific Value
LOI Loss On Ignition
LPO Low pressure oxidation
MHF Multiple Hearth Furnace
MHV Medium heating value
MSW Municipal solid waste
NO Nitrogen oxides
x
PAH Polycyclic aromatic hydrocarbons
PCB Polychlorinated biphenyls
PCDD Polychlorodibenzodioxins
PCDF Polychlorodibenzofurans
RKF Rotary Kiln Furnace
SCR Selective catalytic reduction
SNCR Selective non-catalytic reduction
TOC Total organic carbon
UDG Up-draught or Counter-current gasifier
WWTP Wastewater treatment plant
5 Regulatory aspects
European regulations on thermal treatment of waste have been merged in Directive 2010/75/EU on industrial
emissions. This text merges seven previous European directives concerning the main industrial sectors and
especially the directives on the incineration of wastes (Directive 2000/76/CE) and on integrated pollution
prevention and control (Directive 2008/1/CE).
For the European regulation, an incineration plant is dedicated to the thermal treatment of wastes with or
without recovery of the combustion heat generated. This includes the incineration by oxidation of waste as
well as other thermal treatment processes such as pyrolysis, gasification or plasma processes in so far as the
substances resulting from the treatment are subsequently incinerated (this is not applicable if the gases
resulting from the thermal treatment of waste (pyrolysis or gasification) are purified to such extent that they are
no longer a waste and they cause emission no higher than those resulting from the burning of natural gas).
Incineration plant shall operate with a permit including provisions related to operating condition and emission
limit values. Best Available Techniques shall be considered for all stages of the life cycle of the thermal
treatment plant: conception, operation and closure.
Some of the operating conditions are, among others the following:
— a level of incineration, such that the slag and bottom ashes TOC content, shall be less than 3 % or their
loss on ignition less than 5 % of the dry weight of the material shall be achieved;
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— the gas resulting from the process shall reach, after the last injection of combustion air, in a controlled
and homogeneous fashion and even under the most unfavourable conditions, the temperature of 850 °C.
If hazardous waste with a content of more than 1 % of halogenated organic substances is incinerated the
temperature shall be at least 1 100 °C. These temperatures shall be measured near the inner wall or at
another representative point of the combustion chamber as authorized by the competent authority and
kept for 2 s;
— an automatic system to prevent waste feed shall be operated when temperatures are below prescribed
values;
— any heat generated by the incineration process shall be recovered as far as practicable.
Limits are also given for (i) water discharges from the cleaning of exhaust gases, (ii) flue gas emission and (iii)
residues which shall be recycled, where appropriate, directly in the plant or outside in accordance with
relevant legislation.
The Emission Limit Values (ELV) are fixed in accordance with the emission values which are reachable with
the implementation of the Best Available Techniques (BAT). With the revision of the integrated pollution
prevention and control directive (2008/1/EC) and the publication of the Industrial Emission Directive
(2010/75/EU), the ELV cannot exceed the Best Available Technique associated emission level.
The emission limit values are reported in Annex A. It can be seen that the main difference from the previous
directives is the half-hourly average emission limit values.
6 Sludge properties
6.1 General
Sludge characterization for the assessment of thermochemical processes involves the evaluation of both
technical and economic parameters. The main technical characteristics to evaluate the suitability of
thermochemical processing are dry matter or moisture content, calorific value, ash content. The main
economic parameters are cost of processing, collection and transport, and the characteristics of the recovered
materials and by-products.
6.2 Physico-chemical characteristics
6.2.1 General
The main physico-chemical characteristics to be taken into account are:
— dry matter (or moisture content);
— loss on ignition;
— calorific value;
— amount of grease, scum and screenings.
Physical consistency, together with rheological properties, also play an important role, especially as far as the
design of feeding system is concerned.
6.2.2 Dry matter
The dry matter (DM), or moisture content, is of primary importance for thermal processes because it strongly
affects the Lower Calorific Value (LCV) of organic material which decreases when the moisture content
increases.
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In thermal processing of sewage sludge dry matter is a parameter affecting both fuel requirement and exhaust
gas production. Generally speaking, any incr
...