ISO 13610

Sludge recovery, recycling, treatment and disposal — Determination of calorific value of sludge

This Document specifies a method for the determination of the gross calorific value of sludge at constant volume and at the reference temperature 25 °C in a bomb calorimeter calibrated by combustion of certified benzoic acid. The result obtained is the gross calorific value of the sample at constant volume with both the water of the combustion products and the moisture of the sludge as liquid water. In practice, sludge are burned at constant (atmospheric) pressure and the water is not condensed but is removed as vapour with the flue gases. Under these conditions, the operative heat of combustion to be used is the net calorific value of the fuel at constant pressure. In this European Standard the net calorific value at constant volume is described as it requires less additional determinations. This method is applicable to all kinds of sludge

Valorisation, recyclage, traitement et élimination des boues — Détermination du pouvoir calorifique des boues

General Information

• Status: Not Published
• ICS: 13.030.20 - Liquid wastes. Sludge
• Technical Committee: ISO/TC 275 - Sludge recovery, recycling, treatment and disposal
• Drafting Committee: ISO/TC 275 - Sludge recovery, recycling, treatment and disposal
• Current Stage: 6000 - International Standard under publication
• Start Date: 12-Jun-2025
• Completion Date: 14-Jun-2025

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 13610
ISO/TC 275
Sludge recovery, recycling,
Secretariat: AFNOR
treatment and disposal —
Voting begins on:
Determination of calorific value of
2025-04-16
sludge
Voting terminates on:
2025-06-11
Valorisation, recyclage, traitement et élimination des boues —
Détermination du pouvoir calorifique des boues
This document is circulated as received from the committee secretariat.
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
FAST TRACK PROCEDURE
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 13610:2025(en) © ISO 2025

FINAL DRAFT
ISO/FDIS 13610:2025(en)
International
Standard
ISO/FDIS 13610
ISO/TC 275
Sludge recovery, recycling, treatment
Secretariat: AFNOR
and disposal — Determination of
Voting begins on:
calorific value of sludge
Valorisation, recyclage, traitement et élimination des boues —
Voting terminates on:
Détermination du pouvoir calorifique des boues
This document is circulated as received from the committee secretariat.
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
FAST TRACK PROCEDURE
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 13610:2025(en) © ISO 2025

ii
ISO/FDIS 13610:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 Gross calorific value .2
4.2 Net calorific value .2
5 Reagents . 3
6 Apparatus . 3
6.1 Overview .3
6.2 Calorimeter with thermostat .4
6.3 Crucible, of silica, nickel-chromium, platinum or similar non-reactive material .4
6.4 Ancillary pressure equipment .4
6.5 Timer .5
6.6 Balances .5
6.7 Pellet press .5
7 Procedure . 5
7.1 General .5
7.2 Sample preparation .5
7.3 Preparation of the bomb .6
7.4 Assembling the calorimeter .7
7.5 Combustion reaction and temperature measurements .7
7.6 Disassembling the calorimeter .7
8 Corrections. 8
8.1 Reference temperature .8
8.2 Corrected temperature rise θ .8
8.2.1 General .8
8.2.2 Isoperibol and static jacket calorimeters .8
8.2.3 Adiabatic calorimeters .10
8.2.4 Correction due to the combustion of the ignition wire .10
9 Calibration .10
10 Gross calorific value .11
10.1 General .11
10.2 Calculation of gross calorific value.11
10.3 Expression of results . .11
11 Calculation of net calorific value .12
11.1 General . 12
11.2 Net calorific value at constant volume after hydrogen determination . 12
11.3 Net calorific value at constant pressure . 13
11.4 Expression of results . 13
12 Precision .13
12.1 General . 13
12.2 Repeatability limit . 13
12.3 Reproducibility limit . 13
13 Test report .13
Annex A (informative) Example of a calorimeter . 14
Annex B (informative) Results of the interlaboratory comparison .15

iii
ISO/FDIS 13610:2025(en)
Bibliography .16

iv
ISO/FDIS 13610:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all
...

ISO TC 275
ISO/DIS/FDIS 13610:2024(en)
ISO/TC 275
Secretariat: AFNOR
Date: 2024-09-302025-04-01
Sludge recovery, recycling, treatment and disposal — Determination
of calorific value of sludge
Valorisation, recyclage, traitement et élimination des boues — Détermination du pouvoir calorifique des boues
FDIS stage
ISO/DISFDIS 13610:2023(E2025(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/DISFDIS 13610:20242025(en)
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 Gross calorific value . 2
4.2 Net calorific value . 3
5 Reagents . 3
6 Apparatus . 3
6.1 Overview . 3
6.2 Calorimeter with thermostat . 4
6.4 Crucible, of silica, nickel-chromium, platinum or similar non-reactive material . 5
6.5 Ancillary pressure equipment . 5
6.6 Timer . 5
6.7 Balances . 5
6.8 Pellet press . 5
7 Procedure . 5
7.1 General . 5
7.2 Sample preparation . 6
7.3 Preparation of the bomb . 7
7.4 Assembling the calorimeter . 7
7.5 Combustion reaction and temperature measurements . 7
7.6 Disassembling the calorimeter . 8
8 Corrections . 8
8.1 Reference temperature. 8
8.2 Corrected temperature rise θ . 8
9 Calibration . 11
10 Gross calorific value . 12
10.1 General . 12
10.2 Calculation of gross calorific value . 12
10.3 Expression of results . 13
11 Calculation of net calorific value . 13
11.1 General . 13
11.2 Net calorific value at constant volume after hydrogen determination . 13
11.3 Net calorific value at constant pressure . 14
11.4 Expression of results . 14
12 Precision . 14
12.1 General . 14
12.2 Repeatability limit . 15
12.3 Reproducibility limit . 15
13 Test report . 15
Annex A (informative) Example of a calorimeter . 16
Annex B (informative) Results of the interlaboratory comparison . 19
iii
ISO/DISFDIS 13610:2023(E2025(en)
Bibliography . 20

iv
ISO/DISFDIS 13610:20242025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of
ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO'sISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
This document was originally prepared by the European Committee for Standardization as EN 15170:2008.
The principles and procedures in this document are was adopted unchanged, however, some equipment e.g.
temperature measurement has been modernised. It was assigned to, without modification other than those
given below, by Technical Committee ISO/TC 275, Sludge recovery, recycling, treatment and disposal.
— mercury-in-glass thermometers are replaced by resistance thermometers;
— subclause 7.7 was renumbered as Clause 8,, and adopted under subsequent Clauses and subclauses were
renumbered accordingly;
— the "fast-track procedure".calculation of the net calorific value at constant volume after determination of
water amount in the test (subclause 10.3 in EN 15170:2008) was removed;
— Annex B was removed, and Figure 1 was added in 8.2.2 instead;
— Annex C in EN 15170:2008 is Annex B in this document.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/DISFDIS 13610:2023(E2025(en)
Introduction
The method specified in this document is a simple way to evaluate the amenability of sludge and sludge
products to be treated by thermal processes. In this document, some thermo-chemical corrections are not
considered. For detailed descriptions of analytical procedures and theoretical background see ISO 1928.
The result obtained is the gross calorific value of the sample at constant volume with both the water of the
combustion products and the moisture of the sludge as liquid water. The net calorific value can be derived
from the gross calorific value. For this the hydrogen content of the sludge shall beis determined.
Sludge usually contains much water and (un-burnable) solids. Therefore, the calorific value – especially on the
“as received” basis – is quite low. For many purposes it can be sufficient to determine the gross calorific value
only, and not the net calorific value for which additional determinations are necessary. The calculation of the
net calorific value at constant volume only is described here,; for calculation at constant pressure refer to
ISO 1928.
vi
ISO/DIS 13610:2024(en)
DRAFT International Standard
Sludge recovery, recycling, treatment and disposal — Determination
of calorific value of sludge
1 Scope
This document specifies a method for the determination of the gross calorific value of sludge at constant
volume and at the reference temperature 25 °C in a bomb calorimeter calibrated by combustion of certified
benzoic acid.
The result obtained is the gross calorific value of the sample at constant volume with both the water of the
combustion products and the moisture of the sludge as liquid water. In practice, sludge is burned at constant
(atmospheric) pressure and the water is not condensed but is removed as vapour with the flue gases. Under
these conditions, the operative heat of combustion to be used is the net calorific value of the fuel at constant
pressure. The net calorific value at constant volume can also be used, equations for the calculation are given
only as this requires less additional determinations.
This method is applicable to all kinds of sludge.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 11465, Sludge, treated biowaste, soil and waste — Determination of dry residue or water content and
1)
calculation of the dry matter fraction on a mass basis
ISO 16720, Soil quality — Pretreatment of samples by freeze-drying for subsequent analysis
ISO 29541, Solid mineral fuelsCoa
...