Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for air-purification performance of semiconducting photocatalytic materials — Part 3: Removal of toluene

This document specifies a test method for the determination of the air-purification performance of materials that contain a photocatalyst or have photocatalytic films on the surface, usually made from semiconducting metal oxides, such as titanium dioxide or other ceramic materials, by continuous exposure of a test piece to the model air pollutant under irradiation with ultraviolet light (UV-A). This document is intended for use with different kinds of materials, such as construction materials in flat sheet, board or plate shape, that are the basic forms of materials for various applications. This document also applies to structured filter materials including honeycomb-form, woven and non-woven fabrics, and to plastic or paper materials if they contain ceramic microcrystals and composites. This document does not apply to powder or granular photocatalytic materials. This test method is usually applicable to photocatalytic materials produced for air purification. This method is not suitable for the determination of other performance attributes of photocatalytic materials, i.e. decomposition of water contaminants, self-cleaning, antifogging and antibacterial actions. It concerns the removal of toluene.

Céramiques techniques — Méthodes d'essai relatives à la performance des matériaux photocatalytiques semi-conducteurs pour la purification de l'air — Partie 3: Élimination du toluène

General Information

Status
Published
Publication Date
14-Oct-2019
Technical Committee
Current Stage
6060 - International Standard published
Start Date
15-Oct-2019
Completion Date
15-Oct-2019
Ref Project

RELATIONS

Buy Standard

Standard
ISO 22197-3:2019 - Fine ceramics (advanced ceramics, advanced technical ceramics) -- Test method for air-purification performance of semiconducting photocatalytic materials
English language
12 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 22197-3
Second edition
2019-10
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Test method for air-purification
performance of semiconducting
photocatalytic materials —
Part 3:
Removal of toluene
Céramiques techniques — Méthodes d'essai relatives à la performance
des matériaux photocatalytiques semi-conducteurs pour la
purification de l'air —
Partie 3: Élimination du toluène
Reference number
ISO 22197-3:2019(E)
ISO 2019
---------------------- Page: 1 ----------------------
ISO 22197-3:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 22197-3:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols .......................................................................................................................................................................................................................... 2

5 Principle ........................................................................................................................................................................................................................ 2

6 Apparatus ..................................................................................................................................................................................................................... 3

6.1 Test equipment ....................................................................................................................................................................................... 3

6.2 Test gas supply ........................................................................................................................................................................................ 4

6.3 Photoreactor ............................................................................................................................................................................................. 4

6.4 Light source ............................................................................................................................................................................................... 6

6.5 Analytical system .................................................................................................................................................................................. 6

7 Test piece ...................................................................................................................................................................................................................... 7

8 Procedure..................................................................................................................................................................................................................... 7

8.1 General aspects ....................................................................................................................................................................................... 7

8.2 Pretreatment of test piece ............................................................................................................................................................. 8

8.3 Toluene removal test .......................................................................................................................................................................... 8

9 Calculation .................................................................................................................................................................................................................. 9

10 Test method for test pieces with lower performance .................................................................................................10

11 Test report ................................................................................................................................................................................................................10

Annex A (informative) Results of round-robin test ............................................................................................................................11

Bibliography .............................................................................................................................................................................................................................12

© ISO 2019 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 22197-3:2019(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 206, Fine ceramics.

This second edition cancels and replaces the first edition (ISO 22197-3:2011), which has been technically

revised. The main changes compared to the previous edition are as follows:
— deletion of reference to ISO 2718 (withdrawn) from Clause 2 and 6.5;
— deletion of ISO 4677-1 (withdrawn) from Clause 2 and 8.3.1;
— change of gas flow measurement from dry-gas basis to wet-gas basis in 6.2;
— change of tolerance on dimensions of test piece in Clause 7;
— addition of procedures for removing water-soluble contaminants (8.2);
— addition of criterion for acceptable adsorption of toluene (Clause 9).
A list of all parts in the ISO 22197 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 2019 – All rights reserved
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 22197-3:2019(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for air-purification performance
of semiconducting photocatalytic materials —
Part 3:
Removal of toluene
1 Scope

This document specifies a test method for the determination of the air-purification performance of

materials that contain a photocatalyst or have photocatalytic films on the surface, usually made from

semiconducting metal oxides, such as titanium dioxide or other ceramic materials, by continuous

exposure of a test piece to the model air pollutant under irradiation with ultraviolet light (UV-A).

This document is intended for use with different kinds of materials, such as construction materials in

flat sheet, board or plate shape, that are the basic forms of materials for various applications.

This document also applies to structured filter materials including honeycomb-form, woven and non-

woven fabrics, and to plastic or paper materials if they contain ceramic microcrystals and composites.

This document does not apply to powder or granular photocatalytic materials.

This test method is usually applicable to photocatalytic materials produced for air purification.

This method is not suitable for the determination of other performance attributes of photocatalytic

materials, i.e. decomposition of water contaminants, self-cleaning, antifogging and antibacterial

actions. It concerns the removal of toluene.
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 4892-3, Plastics — Methods of exposure to laboratory light sources — Part 3: Fluorescent UV lamps

ISO 10677, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ultraviolet light source for

testing semiconducting photocatalytic materials

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

ISO 80000-1, Quantities and units — Part 1: General
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

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/
© ISO 2019 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO 22197-3:2019(E)
3.1
photocatalyst

substance that performs one or more functions based on oxidization and reduction reactions under

photoirradiation, including decomposition and removal of air and water contaminants, deodorization,

and antibacterial, self-cleaning and antifogging actions
3.2
photocatalytic materials

materials in which or on which the photocatalyst is added by, for example, coating, impregnation or mixing

Note 1 to entry: Such photocatalytic materials are intended primarily for use as building and road construction

materials to obtain the functions described in 3.1.
3.3
zero-calibration gas

air that does not contain pollutants (i.e. in which common pollutants are below 0,01 µl/l)

Note 1 to entry: The zero-calibration gas is prepared from indoor air using a laboratory air-purification system,

or supplied as synthetic air in a gas cylinder.
3.4
standard gas

diluted gas of known concentration supplied in cylinders and certified by an accredited laboratory

3.5
test gas

mixture of air and pollutant(s) of known concentration prepared from a standard gas or a zero-

calibration gas, to be used for the performance test of a photocatalytic material

3.6
dark condition

test condition with no light irradiation by the light source for testing and room lighting

4 Symbols
For the purposes of this document, the following symbols apply.

f flow rate of test gas converted into that at the standard state (0 °C and 101,3 kPa) (l/min)

ϕ volume fraction of toluene at the reactor exit (µl/l)
ϕ supply volume fraction of toluene (µl/l)
ϕ toluene volume fraction at the reactor exit under dark condition (µl/l)
n quantity of toluene removed by the test piece (µmol)
R removal percentage, by test piece, of toluene (%)
5 Principle

This document concerns the development, comparison, quality assurance, characterization, reliability,

and design data generation of photocatalytic materials (see Reference [1]). The method described is

intended to obtain the air-purification performance of photocatalytic materials by exposing a test

piece to model polluted air under irradiation by ultraviolet (UV) light (Reference [2]). Toluene (C H ) is

7 8
[3]

chosen as a typical aromatic volatile organic compound (VOC) with offensive odour . The test piece,

placed in a flow-type photoreactor, is activated by UV irradiation, and adsorbs and oxidizes gas-phase

toluene to form carbon dioxide (CO ) and other oxidation products (References [4] to [6]). The air-

purification performance is determined from the amount of toluene removed by the test piece, in

2 © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 22197-3:2019(E)

micromoles (μmol). The simple adsorption by the test piece (not due to photocatalysis) is evaluated by

tests in the dark. However, some test pieces adsorb toluene very strongly, and a stable concentration

of toluene may not be attained in the designated time of test. The photocatalytic activity may depend

on physical and chemical properties of pollutants, mainly due to the adsorption process involved. For

a better evaluation of air-purification performance of photocatalytic materials, it is recommended that

one or more suitable test methods are combined as described in other parts of the ISO 22197 series.

6 Apparatus
6.1 Test equipment

The test equipment enables a photocatalytic material to be examined for its pollutant-removal capability

by supplying the test gas continuously, while providing photoirradiation to activate the photocatalyst.

[2]

It is the same as that used in the test method for the removal of nitric oxide (ISO 22197-1 ) and consists

of a test gas supply, a photoreactor, a light source and pollutant-measurement equipment. Since low

concentrations of pollutants are to be tested, the system shall be constructed with materials of low

adsorption and resistant to UV radiation (e.g. acrylic resin, borosilicate glass). An example of a testing

system is shown in Figure 1.
© ISO 2019 – All rights reserved 3
---------------------- Page: 7 ----------------------
ISO 22197-3:2019(E)
Key
1 test gas supply 9 4-way valve
2 air compressor 10 photoreactor
3 air-purification system 11 test piece
4 standard gas (pollutant) 12 air-tight optical window
5 pressure regulator 13 light source
6 mass-flow controller 14 analyser
7 humidifier 15 vent
8 gas mixer
Figure 1 — Schematic diagram of test equipment
6.2 Test gas supply

The test gas supply provides air polluted with the model contaminant at a predetermined concentration,

temperature and humidity, and supplies it continuously to the photoreactor. It consists of flow

regulators, a humidifier, gas mixers and so forth. The flow rate of each gas should be within 5 % of the

designated value, which is easily attained by using thermal mass-flow controllers, with knowledge of

[7]

the temperature and gas type at calibration in accordance with ISO 6145-7 . The expression of gas flow

rate in this document is that converted to the standard state (0 °C and 101,3
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.