BS ISO 22197-5-2013 Fine ceramics (advanced ceramics advanced technical ceramics) Test method for air-purification performance of semiconducting photocatalytic materials Removal of.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 22197-5:2013Fine ceramics (advancedceramics, advanced technicalceramics) Test method forair-purification performance ofsemiconducting photocatalyticmaterialsPart 5: Remova

2、l of methyl mercaptanBS ISO 22197-5:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 22197-5:2013.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this com

3、mittee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 66979 8ICS 81.060.3

4、0Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate Text affectedBS ISO 22197-5:2013 ISO 2013Fine ceramics (adva

5、nced ceramics, advanced technical ceramics) Test method for air-purification performance of semiconducting photocatalytic materials Part 5: Removal of methyl mercaptanCramiques techniques Mthodes dessai relatives la performance des matriaux photocatalytiques semi-conducteurs pour la purification de

6、lair Partie 5: limination du mercaptan mthyliqueINTERNATIONAL STANDARDISO22197-5First edition2013-04-01Reference numberISO 22197-5:2013(E)BS ISO 22197-5:2013ISO 22197-5:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part

7、 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 ISOs member bod

8、y in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 22197-5:2013ISO 22197-5:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12

9、Normative references 13 Terms and definitions . 24 Symbols 25 Principle 36 Apparatus . 36.1 Test equipment . 36.2 Test gas supply 46.3 Photoreactor . 66.4 Light source . 66.5 Analytical system 67 Test piece 78 Procedure. 78.1 General aspects . 78.2 Pretreatment of the test piece . 88.3 Removal test

10、89 Calculation 910 Test method for test pieces with lower performance 911 Test report 10BS ISO 22197-5:2013ISO 22197-5:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Internation

11、al 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,

12、 also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical commit

13、tees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the poss

14、ibility 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.ISO 22197-5 was prepared by Technical Committee ISO/TC 206, Fine ceramics.ISO 22197 consists of the following parts, under the gener

15、al title Fine ceramics (advanced ceramics, advanced technical ceramics) Test method for air-purification performance of semiconducting photocatalytic materials: Part 1: Removal of nitric oxide Part 2: Removal of acetaldehyde Part 3: Removal of toluene Part 4: Removal of formaldehyde Part 5: Removal

16、of methyl mercaptaniv ISO 2013 All rights reservedBS ISO 22197-5:2013INTERNATIONAL STANDARD ISO 22197-5:2013(E)Fine ceramics (advanced ceramics, advanced technical ceramics) Test method for air-purification performance of semiconducting photocatalytic materials Part 5: Removal of methyl mercaptan1 S

17、copeThis part of ISO 22197 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 c

18、ontinuous exposure of a test piece to the model air pollutant under illumination with ultraviolet light (UV-A). This part of ISO 22197 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

19、various applications. This part of ISO 22197 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 part of ISO 22197 does not apply to powder or granular photocat

20、alytic 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 a

21、ntibacterial actions. It concerns the removal of methyl mercaptan.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docume

22、nt (including any amendments) applies.ISO 2718:1974, Standard layout for a method of chemical analysis by gas chromatographyISO 4677-1:1985, Atmospheres for conditioning and testing Determination of relative humidity Part 1: Aspirated psychrometer methodISO 4892-3, Plastics Methods of exposure to la

23、boratory light sources Part 3: Fluorescent UV lampsISO 6145-7:2001, Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods Part 7: Thermal mass-flow controllersISO 10677:2011, Fine ceramics (advanced ceramics, advanced technical ceramics) Ultraviolet light source for t

24、esting semiconducting photocatalytic materialsISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratoriesISO 22197-1:2007, Fine ceramics (advanced ceramics, advanced technical ceramics) Test method for air-purification performance of semiconducting photocataly

25、tic materials Part 1: Removal of nitric oxideISO 80000-1:2009, Quantities and units Part 1: General ISO 2013 All rights reserved 1BS ISO 22197-5:2013ISO 22197-5:2013(E)3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1photocatalystsubstance that p

26、erforms one or more functions based on oxidation and reduction reactions under photoirradiation, including decomposition and removal of air and water contaminants, deodorization, and antibacterial, self-cleaning and antifogging actions3.2photocatalytic materialsmaterials in which or on which the pho

27、tocatalyst is added by coating, impregnation, mixing, etcNote 1 to entry: Such photocatalytic materials are intended primarily for use as building and road construction materials to obtain the above-mentioned functions.3.3zero-calibration gasair that does not contain pollutants (i.e. in which common

28、 pollutants are below 0,01 l/l)Note 1 to entry: The zero-calibration gas is prepared from indoor air, using a laboratory air-purification system, or supplied as a synthetic air in a gas cylinder3.4standard gasdiluted gases of known concentrations supplied in cylinders and certified by an accredited

29、laboratory3.5test gasmixture 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 materialNote 1 to entry: The flow rate, concentration, etc. are expressed at the standard state (0 C, 101,3 kPa)

30、 and dry gas basis (exclusion of water vapour).3.6dark conditiontest condition with no light illumination by the light source for testing and room lightingsNote 1 to entry: Usually the test gas is supplied for comparison with the illuminated reaction.4 SymbolsFor the purposes of this document, the f

31、ollowing symbols apply.f air-flow rate of test gas converted into that at the standard state (l/min, 0 C, 101,3 kPa, dry gas basis)Mthe volume fraction of methyl mercaptan at the reactor exit (l/l)M0the supply volume fraction of methyl mercaptan (l/l)nMthe removal quantity, by test piece, of methyl

32、mercaptan (mol)RMthe removal percentage, by test piece, of methyl mercaptan (%)2 ISO 2013 All rights reservedBS ISO 22197-5:2013ISO 22197-5:2013(E)5 PrincipleThis part of ISO 22197 concerns the development, comparison, quality assurance, characterization, reliability, and design data generation of p

33、hotocatalytic materials. 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-A) light. Methyl mercaptan (methanethiol, CH3SH) is chosen as a typical malodorous subs

34、tance. The test piece, placed in a flow-type photoreactor, is activated by UV irradiation, and adsorbs and oxidizes gas-phase methyl mercaptan. The air-purification performance is determined from the amount of the net removal of methyl mercaptan (mol). The simple adsorption and desorption of CH3SH b

35、y the test piece (not due to photocatalysis) is evaluated by tests in the dark. However, this standard cannot be applied to the test piece which does not give a stable concentration of methyl mercaptan in the designated time of test. The photocatalytic activity may depend on physical and chemical pr

36、operties of pollutants mainly due to the adsorption process involved. For complete evaluation of air purification performance of photocatalytic materials, it is recommended to combine one or more suitable test methods as provided in other parts of ISO 22197.6 Apparatus6.1 Test equipmentThe test equi

37、pment 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. It is the same as that used in the test method for the removal of nitric oxide (ISO 22197-1) and consist

38、s 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 ultraviolet (UV) radiation, for example, acrylic resin, stainless st

39、eel, glass and fluorocarbon polymers. An example of a test system is shown in Figure 1. ISO 2013 All rights reserved 3BS ISO 22197-5:2013ISO 22197-5:2013(E)Dimensions in millimetresPP123100897546101150Key1 light source 7 mass-flow controller2 optical window 8 gas mixers3 test piece 9 humidifier4 sta

40、ndard gas (pollutant) 10 analyser5 air-purification system 11 vent6 compressorFigure 1 Schematic diagram of the test equipment6.2 Test gas supplyThe test gas supply provides air polluted with model contaminant at a predetermined concentration, temperature and humidity, and supplies it continuously t

41、o the photoreactor. It consists of flow regulators, a humidifier, gas mixers, etc. 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 temperature and gas type at calibration in accordance with ISO

42、6145-7. The expression of gas flow rate in this part of ISO 22197 is that converted to the standard state (0 C, 101,3 kPa and dry gas basis). Typical capacities of flow controller for pollutant gas, dry air and wet air are 50 ml/min, 1000 ml/min and 1000 ml/min, 4 ISO 2013 All rights reservedBS ISO

43、22197-5:2013ISO 22197-5:2013(E)respectively. The standard methyl mercaptan gas in a cylinder, normally balanced with nitrogen, shall have a volume fraction of 100 l/l to 1000 l/l.Dimensions in millimetres12355 0,599,5 0,54a) For flat test pieces1246249,5 0,55 0,55799,5 0,53b) For filter-type test pi

44、ecesKey1 window2 test piece3 test gas4 height-adjusting plate5 air layer thickness6 flow channel7 test piece holderFigure 2 Cross-sectional view of photoreactor ISO 2013 All rights reserved 5BS ISO 22197-5:2013ISO 22197-5:2013(E)6.3 PhotoreactorThe photoreactor holds a planar test piece within a 50

45、mm wide trough, with its surface parallel to an optical window for photoirradiation. The reactor shall be fabricated from materials that adsorb little test gas and withstand irradiation of near-UV light. The test piece shall be separated from the window by a 5,0 mm 0,5 mm thick air layer. The test g

46、as shall pass only through the space between the test piece and the window. This gap shall be accurately set up according to the thickness of the test piece, for example, by using height-adjusting plates with different thicknesses, as shown in Figure 2 a). When a filter-type material is tested, an a

47、lternative type of test-piece holder shall be used, which holds the test piece while allowing the test gas to pass through the cells of the filter under irradiation Figure 2 b). Quartz or borosilicate glass that absorbs minimal light at wavelengths longer than 300 nm shall be used for the window.6.4

48、 Light sourceThe light source shall provide UV-A irradiation within a wavelength range of 300 nm to 400 nm. Suitable sources include the so-called black light (BL) and black light blue (BLB) fluorescent lamps, with a maximum at 351 nm, as specified in ISO 4892-3 and ISO 10677. The test piece shall b

49、e irradiated uniformly through the window by the light source. In the case of testing honeycomb-form photocatalysts, the light source shall irradiate one face of the test piece. A light source that requires warming up shall be equipped with a shutter. The distance between the light source and the reactor shall be adjusted so that the UV irradiance (300 nm to 400 nm) at the sample surface is 10 W/m2 0,5 W/m2. The irradiance along the length of the test piece shall also be constant within