SIST-TS CEN ISO/TS 20048-1:2022
(Main)Solid biofuels - Determination of off-gassing and oxygen depletion characteristics - Part 1: Laboratory method for the determination of off-gassing and oxygen depletion using closed containers (ISO/TS 20048-1:2020)
Solid biofuels - Determination of off-gassing and oxygen depletion characteristics - Part 1: Laboratory method for the determination of off-gassing and oxygen depletion using closed containers (ISO/TS 20048-1:2020)
This international standard specifies analytical methods for the determination of off-gassing from and oxygen depletion by solid biofuel pellets. The standard specifies the applicability and use of analytical methods. It further establishes special procedures for sampling and sample handling of solid biofuels pellets prior to the analysis of off-gassing and oxygen depletion. Guidance on the applicability and use of the data on off-gassing and oxygen depletion from the analytical methods is given.
Biogene Festbrennstoffe - Bestimmung von Ausgasungs- und Sauerstoffverarmungseigenschaften - Teil 1: Laboratoriumsverfahren zur Bestimmung von Ausgasung und Sauerstoffverarmung (ISO/TS 20048-1:2020)
Dieses Dokument legt ein Verfahren zur Bestimmung der Ausgasung (Permanentgase) und der Sauerstoffverarmung sowohl aus holzartiger als auch aus nicht-holzartiger Biomasse, einschließlich sowohl gepresster Materialien, wie z. B. Pellets und Briketts, als auch nicht gepresster Materialien, wie z. B. Hackschnitzel, fest. Das Verfahren ist auch auf thermisch behandelte Materialien, einschließlich torrefizierter und carbonisierter Materialien, anwendbar.
Der Emissions und Abreicherungsfaktor und die Emissions- und Verarmungsrate für verschiedene Gasspezies, die aus einer Probe in einem geschlossenen Prüfbehälter emittiert werden, werden mittels Gaschromatographie bestimmt.
Der Emissions- und Abreicherungsfaktor und die Emissions- und Verarmungsrate bieten Orientierungshilfen für die Anforderungen an die Belüftung, um die Gaskonzentrationen in Räumen, in denen Arbeitnehmer der eingeschlossenen Atmosphäre ausgesetzt sein können, unter den zulässigen Expositionsgrenzwerten (PEL, en: Permissible Exposure Levels) zu halten.
Biocombustibles solides - Détermination des dégagements gazeux et de l’appauvrissement en oxygène - Partie 1: Titre manque (ISO/TS 20048-1:2020)
Le présent document définit une méthode de détermination des dégagements gazeux (gaz permanents) et de l'appauvrissement en oxygène de la biomasse ligneuse et non ligneuse, y compris les matériaux densifiés tels que les granulés et les briquettes, ainsi que les matériaux non densifiés tels que les plaquettes. La méthode est également applicable aux matériaux traités thermiquement, y compris les matériaux torréfiés et carbonisés.
Le facteur d'émission et d'appauvrissement et le taux d'émission et d'appauvrissement de diverses espèces gazeuses émises par un échantillon dans un récipient d'essai fermé sont déterminés par chromatographie en phase gazeuse.
Le facteur d'émission et d'appauvrissement et le taux d'émission et d'appauvrissement donnent des indications sur les exigences de ventilation pour maintenir les concentrations de gaz en dessous des niveaux d'exposition admissibles (PEL) dans les espaces où les travailleurs peuvent être exposés à l'atmosphère confinée.
Trdna biogoriva - Določanje značilnosti odvajanja plinov in pomanjkanja kisika - 1. del: Laboratorijska metoda za določanje uhajanja plinov in zmanjšanja kisika z uporabo zaprtih posod (ISO/TS 20048-1:2020)
Ta mednarodni standard določa analitične metode za določanje uhajanja plinov in zmanjšanja kisika s peleti iz trdnih biogoriv. Standard določa namen in uporabo analitskih metod. Vzpostavlja tudi posebne postopke za vzorčenje in ravnanje z vzorci peletov iz trdnih biogoriv pred analizo uhajanja plinov in zmanjšanja kisika. Podane so smernice o namenu in uporabi podatkov o uhajanju plinov in zmanjšanju kisika, pridobljenih z analitskimi metodami.
General Information
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN ISO/TS 20048-1:2022
01-junij-2022
Trdna biogoriva - Določanje značilnosti odvajanja plinov in pomanjkanja kisika - 1.
del: Laboratorijska metoda za določanje uhajanja plinov in zmanjšanja kisika z
uporabo zaprtih posod (ISO/TS 20048-1:2020)
Solid biofuels - Determination of off-gassing and oxygen depletion characteristics - Part
1: Laboratory method for the determination of off-gassing and oxygen depletion using
closed containers (ISO/TS 20048-1:2020)
Biogene Festbrennstoffe - Bestimmung von Ausgasungs- und
Sauerstoffverarmungseigenschaften - Teil 1: Laboratoriumsverfahren zur Bestimmung
von Ausgasung und Sauerstoffverarmung (ISO/TS 20048-1:2020)
Biocombustibles solides - Détermination des dégagements gazeux et de
l’appauvrissement en oxygène - Partie 1: Titre manque (ISO/TS 20048-1:2020)
Ta slovenski standard je istoveten z: CEN ISO/TS 20048-1:2022
ICS:
75.160.40 Biogoriva Biofuels
SIST-TS CEN ISO/TS 20048-1:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TS CEN ISO/TS 20048-1:2022
CEN ISO/TS 20048-1
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
April 2022
TECHNISCHE SPEZIFIKATION
ICS 27.190; 75.160.40
English Version
Solid biofuels - Determination of off-gassing and oxygen
depletion characteristics - Part 1: Laboratory method for
the determination of off-gassing and oxygen depletion
using closed containers (ISO/TS 20048-1:2020)
Biocombustibles solides - Détermination des Biogene Festbrennstoffe - Bestimmung von
dégagements gazeux et de l'appauvrissement en Ausgasungs- und Sauerstoffverarmungseigenschaften -
oxygène - Partie 1: Méthode de laboratoire pour la Teil 1: Laboratoriumsverfahren zur Bestimmung von
détermination des dégagements gazeux et de Ausgasung und Sauerstoffverarmung (ISO/TS 20048-
l'appauvrissement en oxygène dans des récipients 1:2020)
fermés (ISO/TS 20048-1:2020)
This Technical Specification (CEN/TS) was approved by CEN on 27 March 2022 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 20048-1:2022 E
worldwide for CEN national Members.
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CEN ISO/TS 20048-1:2022 (E)
Contents Page
European foreword . 3
2
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SIST-TS CEN ISO/TS 20048-1:2022
CEN ISO/TS 20048-1:2022 (E)
European foreword
The text of ISO/TS 20048-1:2020 has been prepared by Technical Committee ISO/TC 238 "Solid
biofuels” of the International Organization for Standardization (ISO) and has been taken over as
CEN ISO/TS 20048-1:2022 by Technical Committee CEN/TC 335 “Solid biofuels” the secretariat of
which is held by SIS.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/TS 20048-1:2020 has been approved by CEN as CEN ISO/TS 20048-1:2022 without any
modification.
3
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SIST-TS CEN ISO/TS 20048-1:2022
TECHNICAL ISO/TS
SPECIFICATION 20048-1
First edition
2020-03
Solid biofuels — Determination of
off-gassing and oxygen depletion
characteristics —
Part 1:
Laboratory method for the
determination of off-gassing and
oxygen depletion using closed
containers
Reference number
ISO/TS 20048-1:2020(E)
©
ISO 2020
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SIST-TS CEN ISO/TS 20048-1:2022
ISO/TS 20048-1:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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
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Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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ISO/TS 20048-1:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 General . 3
5.2 Test containers . 3
5.3 Gas sampler. 5
5.4 Ovens . 5
5.5 Gas chromatograph (GC) analyser . 5
6 Biomass sampling and sample preparation . 6
6.1 General . 6
6.2 Test sample characterization . 6
6.3 Test sample size . 6
7 Procedure. 6
7.1 Determination of porosity in biomass test sample . 6
7.2 Filling of test containers . 7
7.3 Test container arrangement and test gas sampling volume . 7
7.4 Operation of temperature-controlled ovens . 8
7.5 Gas sampling procedure . 8
7.6 Gas analysis . 9
8 Calculation . 9
9 Test report .13
Annex A (normative) Quantification of gas species using chromatography .14
Annex B (informative) Estimation of ventilation requirements for enclosed spaces .16
Annex C (informative) Determination of gas species concentration in open storage space .19
Bibliography .20
© ISO 2020 – All rights reserved iii
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ISO/TS 20048-1:2020(E)
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 238, Solid biofuels.
A list of all parts in the ISO 20048 series can be found on the ISO website.
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.
iv © ISO 2020 – All rights reserved
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ISO/TS 20048-1:2020(E)
Introduction
There is a continuous global growth in production, storage, handling, bulk transport and use of solid
biofuels especially in the form of pelletized biofuels.
The specific physical and chemical characteristics of solid biofuels, their handling and storage can lead
to a risk of fire and/or explosion, as well as health risks such as intoxication due to exposure to carbon-
monoxide, asphyxiation due to oxygen depletion or allergic reactions.
Emission from pellets or biomass stored in enclosed space represents a significant health risk due to
exposure to carbon-monoxide (CO) and oxygen depletion. It is important to be able to assess the risk by
quantifying the emission of CO in combination with oxygen level. This document describes a method for
estimating the propensity of a particular quality of pellets or biomass to emit CO, CO , CH as well as the
2 4
depletion of oxygen within the stored environment. In a confined space, the gas composition can result
in a toxic as well as explosive atmosphere.
Biomass species, age of the material as well as the ambient temperature impacts the dynamics of the gas
emissions. Unless the level of CO and oxygen levels are well understood in an operating environment,
there are inherent risk for workers, which have implications for liability.
This document specifies the methodology for measuring the emission and depletion factor and emission
and depletion rate of off-gassing in combination with oxygen depletion for permanent gases emitted in
an enclosed storage for biomass.
NOTE A method to be used in preliminary screening of CO for operational planning is currently under
development within ISO/TC 238/WG 7. Stage at the time of publication ISO/CD 20048-2:2018.
The method described in this document uses highly sensitive gas chromatography to be able to identify
the spectrum of gases and their relative concentration to predict the potential for unhealthy conditions
during indoor storage of biomass. The sensitivity for detection of gas species and concentrations is
only limited by the sensitivity of the chromatographic instrument. The method allows for estimation
of emission and depletion factor and emission and depletion rate for each gas species of biomass at
different storage temperatures.
The gas instrument analysis part of the method also allows for identification of gas species and
determination of concentrations of gases sampled in open storage spaces for occupational hygiene
purposes (Annex C).
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SIST-TS CEN ISO/TS 20048-1:2022
TECHNICAL SPECIFICATION ISO/TS 20048-1:2020(E)
Solid biofuels — Determination of off-gassing and oxygen
depletion characteristics —
Part 1:
Laboratory method for the determination of off-gassing
and oxygen depletion using closed containers
1 Scope
This document defines a method for determination of off-gassing (permanent gases) and oxygen
depletion from woody as well as non-woody biomass, including densified materials such as pellets and
briquettes, as well as non-densified materials such as chips. The method is also applicable for thermally
treated materials, including torrefied and carbonized materials.
The emission and depletion factor and emission and depletion rate for various gas species emitted from
sample within a closed test container is determined by means of gas chromatography.
The emission and depletion factor and emission and depletion rate provide guidance for ventilation
requirements to keep gas concentrations below Permissible Exposure Levels (PEL) in spaces where
workers can be exposed to the enclosed atmosphere.
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 16559, Solid biofuels — Terminology, definitions and descriptions
ISO 18135, Solid biofuels — Sampling
ISO 14780, Solid biofuels — Sample preparation
ISO 17827-2, Solid biofuels — Determination of particle size distribution for uncompressed fuels — Part 2:
Vibrating screen method using sieves with aperture of 3,15 mm and below
ISO 17828, Solid biofuels — Determination of bulk density
ISO 18134-1, Solid biofuels — Determination of moisture content — Oven dry method — Part 1: Total
moisture — Reference method
ISO 18134-2, Solid biofuels — Determination of moisture content — Oven dry method — Part 2: Total
moisture — Simplified method
ISO 18846, Solid biofuels — Determination of fines content in quantities of pellets
ISO 18847, Solid biofuels — Determination of particle density of pellets and briquettes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16559 and the following apply.
© ISO 2020 – All rights reserved 1
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ISO/TS 20048-1:2020(E)
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
emission factor
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram of the substance emitting at a given temperature
3.2
depletion factor
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram of the substance depleting at a given temperature
3.3
emission rate
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram per day of the substance emitting at a given temperature
3.4
depletion rate
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram per day of the substance depleting at a given temperature
3.5
ppmv
parts per million on volume basis
3.6
gas chromatograph
GC
instrument used in analytical chemistry for separating and analysing compounds that can be
vapourized without decomposition
3.7
Permissible Exposure Level
PEL
regulatory limit on the amount or concentration of a substance in the air
Note 1 to entry: This is usually based on an eight-hour time weighted average, but some are based on short-term
exposure limits.
4 Principle
One or more test container(s) sealed with an air-tight lid and partly filled with biomass test sample are
placed in oven with controlled temperature such as 20 °C, 30 °C, 40 °C or 50 °C. Gas samples are drawn
by means of a syringe through the sampling port of the container(s) and the relative concentration
of gas species is quantified by means of a gas chromatograph. The concentration is converted from
a volume fraction in % relative to other gases in the test container and expressed as emission and
depletion factor in gram per kilogram of biomass at a given temperature. The emission and depletion
rate are expressed as gram of gas species per kilogram of biomass per day at a given temperature.
A method for converting emission and depletion factor (ppmv) concentration and calculating the
number of air exchanges in a space with controlled ventilation is provided in Annex B.
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ISO/TS 20048-1:2020(E)
5 Apparatus
5.1 General
All equipment holding biomass samples and gas samples extracted during the determination shall be
free of any contaminants, well ventilated and dry before the off-gassing test starts.
NOTE Containers and fittings can be dried overnight at low temperature around 30 °C.
5.2 Test containers
The test container(s) shall preferably be made of glass, not plastic, due to the risk of contaminating
gases from plastic materials at higher temperatures. Since the containers shall only be filled to 75 %
with biomass to be tested, it is an advantage to be able to see the level of biomass from the outside.
Figure 1 a) to 1 c) show photos of the test container with sampling port and Figure 2 shows a schematic
of the test container and sampling port.
a) Test container of glass with sampling port
b) Sampling port, from the side
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SIST-TS CEN ISO/TS 20048-1:2022
ISO/TS 20048-1:2020(E)
c) Sampling port, from above
Figure 1 — Example of test container of glass with sampling port
Key
1 septum
2 nipple
3 sampling port
4 container lid
5 air-tight seal
6 test container
Figure 2 — Schematic of test container with sampling port
The headspace in an enclosed container shall contain sufficient oxygen to sustain oxidation of test
[1][2]
sample to reach a peak (plateau) and allow determination of the emission and depletion factor . The
25 % headspace of enclosed air volume under roof in a typical large-scale storage facility such as a silo
when fully loaded is typical and is therefore selected for this test method.
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ISO/TS 20048-1:2020(E)
The seal between the lid and the container as well as the sampling port nipple (septum) shall be made
of polytetrafluoroethylene (PTFE) or neoprene, which are non-reactive materials at the temperatures
recommended for the off-gassing tests. Gas samples shall be drawn using a syringe (see 5.3) piercing
through the septum.
The effective gas volume in a test container can be expressed in accordance with Formula (1).
VV=+VV=×02, 5 +V (1)
hv cv
where
V is the effective gas volume in test container when filled with biomass;
V =×02, 5 V is the selected headspace volume;
h c
V is the volume of void between the biomass particles;
v
V is the volume of empty test container.
c
EXAMPLE
The effective gas volume (V) for a test container with a volume of 3 500 ml (V ) loaded to 75 % with wood pellets
c
and with a volume of void of 50 % can be calculated as follows:
V = 0,25 × 3 500 [ml]+0,75 × 3 500 [ml] × 0,5 = 3 500 [ml] × 0,625 = 2 188 ml
Guidance for selecting container size in relation to gas sample size required by the GC for a selected gas
depletion volume is provided in 7.3.
5.3 Gas sampler
A gas-tight GC syringe shall be used for drawing gas test samples through septum in the container
sampling port nipple. It is recommended that the capacity of the syringe be at least 3 times the volume
of the sampling tube and sampling loop of the GC or as recommended by the manufacturer of the GC
(see 5.5). The syringe shall have a scale with a resolution of 1 ml and a valve to secure the sample after
drawing. It is best to use needles that have a hole on the side rather than the tip to prevent silicone or
neoprene material blocking the hole while sampling.
The gas sample is injected directly from the sampler syringe into the GC sample port.
5.4 Ovens
The temperature within the test containers shall be controlled by placing the containers in ovens
automatically controlling the temperature in the range of 20 °C to 50 °C ± 1 °C. A separate oven is
required for each temperature selected for testing. The ovens shall be able to hold the size of containers
required to achieve the necessary accuracy of the off-gassing determination.
[4]
Since temperature of biomass under test has a propensity to self-generate heat at testing temperatures
above 40 °C, particularly if the moisture in the material is high, a thermocouple should be placed
inside the material in one of the containers. A thermocouple in the centre of the test volume will help
monitoring the uniformity of the temperature.
5.5 Gas chromatograph (GC) analyser
The detection limit for each gas species and related concentrations is determined by the type of column
in the GC. The manufacturer of the GC should be consulted. GC with thermal conductivity detector (TCD)
shall be used to detect and quantify permanent gases and light hydrocarbons. Packed and capillary
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ISO/TS 20048-1:2020(E)
columns could be used with TCD to measure permanent gases. A combination of TCD and FID (flame
ionization detector) could also be used for gas measurements depending on the GC configuration.
NOTE 1 Helium (He) is usually used as carrier gas but, e.g., nitrogen or argon are other possible alternatives.
NOTE 2 PEL for CO is in the range of 25 ppmv to 100 ppmv depending on jurisdiction and on the duration of
the exposure. Gas chromatography allows identification of a large number of non-condensable like CO, CO , CH ,
2 4
N , H , and O . The PEL for those compounds can be found in occupational hygiene databases. The occupational
2 2 2
health lower limit for oxygen is 19,5 %.
Annex A provides a generic orientation of operation and calibration of a GC.
6 Biomass sampling and sample preparation
6.1 General
Sampling and sample preparation of biomass shall be done in accordance with ISO 18135 and ISO 14780
respectively.
6.2 Test sample characterization
The test sample characterization shall be done in accordance with the following international standards;
a) Moisture ISO 18134-1 or ISO 18134-2
b) Particle size distribution ISO 17827-2
c) Fines content ISO 18846
d) Bulk density ISO 17828
e) Particle density ISO 18847
If available, note the origin, species and age of the test sample in the test report (Clause 9).
6.3 Test sample size
The total sample size depends on the test container configuration selected (7.3). At least three test
sample fractions shall be prepared; one for test sample characterization (6.2) and the others for off-
gassing/oxygen depletion tests.
EXAMPLE
Volume of material required per temperature test is V × 4 plus required volume for characterization depending
c
on the selected test under 6.2. Material for each additional test temperature requires V × 4.
c
7 Procedure
7.1 Determination of porosity in biomass test sample
The characteristics of the biomass test sample can vary depending on shape and size of the material as
well as amount of entrained dust.
[7]
For pellets the bed porosity (or bulk porosity of the bed) is determined using Formula (2) :
ρ
b
ε=−1 (2)
ρ
d
where
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ISO/TS 20048-1:2020(E)
ρ is the bulk density (ISO 17828) and
b
ρ is the single particle density (ISO 18847) of wood pellet.
d
7.2 Filling of test containers
Mark the test con
...
SLOVENSKI STANDARD
kSIST-TS FprCEN ISO/TS 20048-1:2022
01-februar-2022
Trda biogoriva - Določanje značilnosti odvajanja plinov in pomanjkanja kisika - 1.
del: Laboratorijska metoda za določanje uhajanja plinov in zmanjšanja kisika z
uporabo zaprtih posod (ISO/TS 20048-1:2020)
Solid biofuels - Determination of off-gassing and oxygen depletion characteristics - Part
1: Laboratory method for the determination of off-gassing and oxygen depletion using
closed containers (ISO/TS 20048-1:2020)
Biogene Festbrennstoffe - Bestimmung von Ausgasungs- und
Sauerstoffverarmungseigenschaften - Teil 1: Laboratoriumsverfahren zur Bestimmung
von Ausgasung und Sauerstoffverarmung (ISO/TS 20048-1:2020)
Biocombustibles solides - Détermination des dégagements gazeux et de
l’appauvrissement en oxygène - Partie 1: Titre manque (ISO/TS 20048-1:2020)
Ta slovenski standard je istoveten z: FprCEN ISO/TS 20048-1
ICS:
75.160.40 Biogoriva Biofuels
kSIST-TS FprCEN ISO/TS 20048-1:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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kSIST-TS FprCEN ISO/TS 20048-1:2022
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kSIST-TS FprCEN ISO/TS 20048-1:2022
TECHNICAL ISO/TS
SPECIFICATION 20048-1
First edition
2020-03
Solid biofuels — Determination of
off-gassing and oxygen depletion
characteristics —
Part 1:
Laboratory method for the
determination of off-gassing and
oxygen depletion using closed
containers
Reference number
ISO/TS 20048-1:2020(E)
©
ISO 2020
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kSIST-TS FprCEN ISO/TS 20048-1:2022
ISO/TS 20048-1:2020(E)
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© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 General . 3
5.2 Test containers . 3
5.3 Gas sampler. 5
5.4 Ovens . 5
5.5 Gas chromatograph (GC) analyser . 5
6 Biomass sampling and sample preparation . 6
6.1 General . 6
6.2 Test sample characterization . 6
6.3 Test sample size . 6
7 Procedure. 6
7.1 Determination of porosity in biomass test sample . 6
7.2 Filling of test containers . 7
7.3 Test container arrangement and test gas sampling volume . 7
7.4 Operation of temperature-controlled ovens . 8
7.5 Gas sampling procedure . 8
7.6 Gas analysis . 9
8 Calculation . 9
9 Test report .13
Annex A (normative) Quantification of gas species using chromatography .14
Annex B (informative) Estimation of ventilation requirements for enclosed spaces .16
Annex C (informative) Determination of gas species concentration in open storage space .19
Bibliography .20
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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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 238, Solid biofuels.
A list of all parts in the ISO 20048 series can be found on the ISO website.
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.
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Introduction
There is a continuous global growth in production, storage, handling, bulk transport and use of solid
biofuels especially in the form of pelletized biofuels.
The specific physical and chemical characteristics of solid biofuels, their handling and storage can lead
to a risk of fire and/or explosion, as well as health risks such as intoxication due to exposure to carbon-
monoxide, asphyxiation due to oxygen depletion or allergic reactions.
Emission from pellets or biomass stored in enclosed space represents a significant health risk due to
exposure to carbon-monoxide (CO) and oxygen depletion. It is important to be able to assess the risk by
quantifying the emission of CO in combination with oxygen level. This document describes a method for
estimating the propensity of a particular quality of pellets or biomass to emit CO, CO , CH as well as the
2 4
depletion of oxygen within the stored environment. In a confined space, the gas composition can result
in a toxic as well as explosive atmosphere.
Biomass species, age of the material as well as the ambient temperature impacts the dynamics of the gas
emissions. Unless the level of CO and oxygen levels are well understood in an operating environment,
there are inherent risk for workers, which have implications for liability.
This document specifies the methodology for measuring the emission and depletion factor and emission
and depletion rate of off-gassing in combination with oxygen depletion for permanent gases emitted in
an enclosed storage for biomass.
NOTE A method to be used in preliminary screening of CO for operational planning is currently under
development within ISO/TC 238/WG 7. Stage at the time of publication ISO/CD 20048-2:2018.
The method described in this document uses highly sensitive gas chromatography to be able to identify
the spectrum of gases and their relative concentration to predict the potential for unhealthy conditions
during indoor storage of biomass. The sensitivity for detection of gas species and concentrations is
only limited by the sensitivity of the chromatographic instrument. The method allows for estimation
of emission and depletion factor and emission and depletion rate for each gas species of biomass at
different storage temperatures.
The gas instrument analysis part of the method also allows for identification of gas species and
determination of concentrations of gases sampled in open storage spaces for occupational hygiene
purposes (Annex C).
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TECHNICAL SPECIFICATION ISO/TS 20048-1:2020(E)
Solid biofuels — Determination of off-gassing and oxygen
depletion characteristics —
Part 1:
Laboratory method for the determination of off-gassing
and oxygen depletion using closed containers
1 Scope
This document defines a method for determination of off-gassing (permanent gases) and oxygen
depletion from woody as well as non-woody biomass, including densified materials such as pellets and
briquettes, as well as non-densified materials such as chips. The method is also applicable for thermally
treated materials, including torrefied and carbonized materials.
The emission and depletion factor and emission and depletion rate for various gas species emitted from
sample within a closed test container is determined by means of gas chromatography.
The emission and depletion factor and emission and depletion rate provide guidance for ventilation
requirements to keep gas concentrations below Permissible Exposure Levels (PEL) in spaces where
workers can be exposed to the enclosed atmosphere.
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 16559, Solid biofuels — Terminology, definitions and descriptions
ISO 18135, Solid biofuels — Sampling
ISO 14780, Solid biofuels — Sample preparation
ISO 17827-2, Solid biofuels — Determination of particle size distribution for uncompressed fuels — Part 2:
Vibrating screen method using sieves with aperture of 3,15 mm and below
ISO 17828, Solid biofuels — Determination of bulk density
ISO 18134-1, Solid biofuels — Determination of moisture content — Oven dry method — Part 1: Total
moisture — Reference method
ISO 18134-2, Solid biofuels — Determination of moisture content — Oven dry method — Part 2: Total
moisture — Simplified method
ISO 18846, Solid biofuels — Determination of fines content in quantities of pellets
ISO 18847, Solid biofuels — Determination of particle density of pellets and briquettes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16559 and the following apply.
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ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
emission factor
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram of the substance emitting at a given temperature
3.2
depletion factor
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram of the substance depleting at a given temperature
3.3
emission rate
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram per day of the substance emitting at a given temperature
3.4
depletion rate
concentration in percent of a gas species relative to other gases in a volume and expressed in gram per
kilogram per day of the substance depleting at a given temperature
3.5
ppmv
parts per million on volume basis
3.6
gas chromatograph
GC
instrument used in analytical chemistry for separating and analysing compounds that can be
vapourized without decomposition
3.7
Permissible Exposure Level
PEL
regulatory limit on the amount or concentration of a substance in the air
Note 1 to entry: This is usually based on an eight-hour time weighted average, but some are based on short-term
exposure limits.
4 Principle
One or more test container(s) sealed with an air-tight lid and partly filled with biomass test sample are
placed in oven with controlled temperature such as 20 °C, 30 °C, 40 °C or 50 °C. Gas samples are drawn
by means of a syringe through the sampling port of the container(s) and the relative concentration
of gas species is quantified by means of a gas chromatograph. The concentration is converted from
a volume fraction in % relative to other gases in the test container and expressed as emission and
depletion factor in gram per kilogram of biomass at a given temperature. The emission and depletion
rate are expressed as gram of gas species per kilogram of biomass per day at a given temperature.
A method for converting emission and depletion factor (ppmv) concentration and calculating the
number of air exchanges in a space with controlled ventilation is provided in Annex B.
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5 Apparatus
5.1 General
All equipment holding biomass samples and gas samples extracted during the determination shall be
free of any contaminants, well ventilated and dry before the off-gassing test starts.
NOTE Containers and fittings can be dried overnight at low temperature around 30 °C.
5.2 Test containers
The test container(s) shall preferably be made of glass, not plastic, due to the risk of contaminating
gases from plastic materials at higher temperatures. Since the containers shall only be filled to 75 %
with biomass to be tested, it is an advantage to be able to see the level of biomass from the outside.
Figure 1 a) to 1 c) show photos of the test container with sampling port and Figure 2 shows a schematic
of the test container and sampling port.
a) Test container of glass with sampling port
b) Sampling port, from the side
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c) Sampling port, from above
Figure 1 — Example of test container of glass with sampling port
Key
1 septum
2 nipple
3 sampling port
4 container lid
5 air-tight seal
6 test container
Figure 2 — Schematic of test container with sampling port
The headspace in an enclosed container shall contain sufficient oxygen to sustain oxidation of test
[1][2]
sample to reach a peak (plateau) and allow determination of the emission and depletion factor . The
25 % headspace of enclosed air volume under roof in a typical large-scale storage facility such as a silo
when fully loaded is typical and is therefore selected for this test method.
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The seal between the lid and the container as well as the sampling port nipple (septum) shall be made
of polytetrafluoroethylene (PTFE) or neoprene, which are non-reactive materials at the temperatures
recommended for the off-gassing tests. Gas samples shall be drawn using a syringe (see 5.3) piercing
through the septum.
The effective gas volume in a test container can be expressed in accordance with Formula (1).
VV=+VV=×02, 5 +V (1)
hv cv
where
V is the effective gas volume in test container when filled with biomass;
V =×02, 5 V is the selected headspace volume;
h c
V is the volume of void between the biomass particles;
v
V is the volume of empty test container.
c
EXAMPLE
The effective gas volume (V) for a test container with a volume of 3 500 ml (V ) loaded to 75 % with wood pellets
c
and with a volume of void of 50 % can be calculated as follows:
V = 0,25 × 3 500 [ml]+0,75 × 3 500 [ml] × 0,5 = 3 500 [ml] × 0,625 = 2 188 ml
Guidance for selecting container size in relation to gas sample size required by the GC for a selected gas
depletion volume is provided in 7.3.
5.3 Gas sampler
A gas-tight GC syringe shall be used for drawing gas test samples through septum in the container
sampling port nipple. It is recommended that the capacity of the syringe be at least 3 times the volume
of the sampling tube and sampling loop of the GC or as recommended by the manufacturer of the GC
(see 5.5). The syringe shall have a scale with a resolution of 1 ml and a valve to secure the sample after
drawing. It is best to use needles that have a hole on the side rather than the tip to prevent silicone or
neoprene material blocking the hole while sampling.
The gas sample is injected directly from the sampler syringe into the GC sample port.
5.4 Ovens
The temperature within the test containers shall be controlled by placing the containers in ovens
automatically controlling the temperature in the range of 20 °C to 50 °C ± 1 °C. A separate oven is
required for each temperature selected for testing. The ovens shall be able to hold the size of containers
required to achieve the necessary accuracy of the off-gassing determination.
[4]
Since temperature of biomass under test has a propensity to self-generate heat at testing temperatures
above 40 °C, particularly if the moisture in the material is high, a thermocouple should be placed
inside the material in one of the containers. A thermocouple in the centre of the test volume will help
monitoring the uniformity of the temperature.
5.5 Gas chromatograph (GC) analyser
The detection limit for each gas species and related concentrations is determined by the type of column
in the GC. The manufacturer of the GC should be consulted. GC with thermal conductivity detector (TCD)
shall be used to detect and quantify permanent gases and light hydrocarbons. Packed and capillary
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columns could be used with TCD to measure permanent gases. A combination of TCD and FID (flame
ionization detector) could also be used for gas measurements depending on the GC configuration.
NOTE 1 Helium (He) is usually used as carrier gas but, e.g., nitrogen or argon are other possible alternatives.
NOTE 2 PEL for CO is in the range of 25 ppmv to 100 ppmv depending on jurisdiction and on the duration of
the exposure. Gas chromatography allows identification of a large number of non-condensable like CO, CO , CH ,
2 4
N , H , and O . The PEL for those compounds can be found in occupational hygiene databases. The occupational
2 2 2
health lower limit for oxygen is 19,5 %.
Annex A provides a generic orientation of operation and calibration of a GC.
6 Biomass sampling and sample preparation
6.1 General
Sampling and sample preparation of biomass shall be done in accordance with ISO 18135 and ISO 14780
respectively.
6.2 Test sample characterization
The test sample characterization shall be done in accordance with the following international standards;
a) Moisture ISO 18134-1 or ISO 18134-2
b) Particle size distribution ISO 17827-2
c) Fines content ISO 18846
d) Bulk density ISO 17828
e) Particle density ISO 18847
If available, note the origin, species and age of the test sample in the test report (Clause 9).
6.3 Test sample size
The total sample size depends on the test container configuration selected (7.3). At least three test
sample fractions shall be prepared; one for test sample characterization (6.2) and the others for off-
gassing/oxygen depletion tests.
EXAMPLE
Volume of material required per temperature test is V × 4 plus required volume for characterization depending
c
on the selected test under 6.2. Material for each additional test temperature requires V × 4.
c
7 Procedure
7.1 Determination of porosity in biomass test sample
The characteristics of the biomass test sample can vary depending on shape and size of the material as
well as amount of entrained dust.
[7]
For pellets the bed porosity (or bulk porosity of the bed) is determined using Formula (2) :
ρ
b
ε=−1 (2)
ρ
d
where
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ρ is the bulk density (ISO 17828) and
b
ρ is the single particle density (ISO 18847) of wood pellet.
d
7.2 Filling of test containers
Mark the test container at the 75 % level.
Fill each container to the 85 % level with the biomass test material to be tested. In order to achieve a
representative packing density, expose the test container to shock by means of dropping the container
5 times from a height of 50 mm onto a wooden board on an even horizontal and hard workbench or
floor. Make sure the test container hits the wooden board in a vertical position and that the level of test
material reaches the 75 % level. Refill or remove material if necessary, to reach the 75 % level. This
procedure shall be repeated until the packing density is stable.
If more than one test container is used, mark the containers with different letters A, B, C etc., and weigh
the content of each container to make sure each container has the same weight within 1 % of weight.
If there is dust remaining on the rim of the test container, swipe it off with a cloth.
Apply the lid assembly with the sampling port to the test container and seal it. Tighten all connections.
To make it air-tight, use an extra sealant, such as silicone, around the fittings on the side of the lid that
is exposed to air when the container is closed, No extra sealant shall be used on the inner side of the lid.
Ensure that the sealant chosen can be used in the temperatures it will be exposed to during the test.
The container called PEAK is sampled only once when the sampling is completed. It is to verify the peak
emission value at the end of the test period.
7.3 Test container arrangement and test gas sampling volume
The different gas species evolve at different rates, which mean that the relative ratio of gases can
change slightly over time as the oxygen is consumed. Also, the temperature can affect the relative rate
of evolution of the various gas species. The oxygen content in the containment is depleted as a function
of oxidation of components of the biomass. In order to obtain a representative profile of emissions for
long term storage, emission and depletion factors and emission and depletion rates for gas species shall
be defined over an extended period of time such as 28 to 30 days. Due to this relatively long period
of time, considerations shall be given to testing more than one biomass test material at a time. For
example, reference material and several test samples can be processed in parallel. If testing is done at
various temperatures such as 20 °C/30 °C/40 °C/50 °C there shall be one oven per temperature.
NOTE Using more than one oven per temperature is not recommended since there will be some difference in
the temperature which could affect the results.
Consideration shall be given to maximum allowable gas depletion due to sampling and the number of
days samples should be taken.
Figure 3 illustrates arrangements of four test containers in an oven.
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Key
1 oven with temperature regulator
2 test containers marked A, B and C
3 reference test container marked PEAK
Figure 3 — Schematic of oven and test container configuration
7.4 Operation of temperature-controlled ovens
The temperature of the ovens has to be stabilized at the selected temperature before the test
container(s) are loaded into the ovens. Ideally there should be multiple ovens operated in parallel with
temperatures controlled at 20/30/40/50 °C or other selected temperatures to run the tests in parallel
to save time and to make sure the material is of the same age.
NOTE If the room temperature is fairly stable, the 20 °C test can be done without an oven.
7.5 Gas sampling procedure
Remove the test containers from the oven during the sampling and rotate it along its axis at least
once before the syringe is inserted to draw the gas sample. This will mix the gases and minimize the
potential for un-even distribution of gases within the test container. During sampling the door of the
oven shall be open as short time as possible and the test containers shall not be outside the oven more
than necessary.
After completion of sampling, place the test containers in the oven. Use gloves, protective glasses and
ot
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