1、BRITISH STANDARD BS ISO 11632:1998 Stationary source emissions Determination of mass concentration of sulfur dioxide Ion chromatography method ICS 13.040.40BSISO 11632:1998 This British Standard, having been prepared under the directionof the Health and Environment Sector Board, waspublished under t
2、he authorityof the Standards Boardand comes into effect on 15May1998 BSI 04-1999 ISBN 0 580 29625 3 National foreword This British Standard reproduces verbatim ISO11632:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee EH
3、/2, Air quality, to Subcommittee EH/2/1, Stationary source emissions, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; m
4、onitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in thi
5、s document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. User
6、s of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pagesii toiv, pages1 t
7、o14 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS ISO 11632:1998 BSI 04-1999 i Contents Page Nationa
8、l foreword Inside front cover Foreword iii Text of ISO 11632 1ii blankBS ISO11632:1998 ii BSI 04-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Principle 1 4 Reagents 2 5 Apparatus 2 6 Sampling 6 7 Analytical procedure 8 8 Expression of results 11 9 Performance c
9、haracteristics 12 10 Test report 12 Annex A (informative) Example of a quality control programme 13 Figure 1 Positioning of sampling probe, filter holder and protective tube 3 Figure 2 Example of a particle filter and filter holder 4 Figure 3 Example of an absorption bottle 5 Figure 4 Example of an
10、ion chromatograph 7 Figure 5 Sampling system 9 Table 1 Standard deviations under repeatability conditions 12 Descriptors: Air, quality, air pollution, exhaust emissions, gas emissions, chemical analysis, determination of content, sulphur dioxide, concentration, chromatographic analysis.BS ISO11632:1
11、998 BSI 04-1999 iii 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 s
12、ubject 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
13、(IEC) on all matters of electrotechnical standardization. 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 least75% of the member bodies casting a vote. International Sta
14、ndard ISO11632 was prepared by Technical committee ISO/TC146, Air quality, Subcommittee SC1, Stationary source emissions. Annex A of this International Standard is for information only.iv blankBSISO11632:1998 BSI 04-1999 1 Introduction For determining the mass concentration of sulfur dioxide in wast
15、e gas of stationary emissions sources, several integrated sampling and analysis methods exist. These include methods for independent manual sampling ISO7934 and for automated measuring systems ISO7935. The latter have found a greater usage since a continuous measurement of sulfur dioxide, often spec
16、ified by environmental authorities, can be obtained. The manual methods are required however, in calibrating automated measuring instruments. This International Standard offers an alternative method to ISO7934, replacing the Thorin method for analysing sulfate ions by a method based on ion chromatog
17、raphy. In addition, this International Standard is intended to apply to a lower emission range than ISO7934. 1 Scope This International Standard specifies a method for the determination of the mass concentration of sulfur dioxide emitted from combustion facilities and technical processes, and define
18、s the most important performance characteristics. The method described in this International Standard has been tested for a sulfur dioxide concentration range of6mg/m 3to333mg/m 3with sampling periods of30min. It is applicable to mass concentrations of sulfur dioxide exceeding this range by carrying
19、 out an appropriate dilution of the sample solutions prior to the analysis or by using larger volumes of absorption solution, and to sulfur dioxide concentrations below this range by extending the sampling period. This International Standard is applicable to the analysis of samples containing neglig
20、ible levels of sulfur trioxide and volatile sulfates (5% of the expected sulfur dioxide concentration), and ammonia(5mg/m 3 ). All concentrations are based on dry gas at a temperature of273,2K and pressure of101,3kPa. 2 Normative references The following standards contain provisions which, through r
21、eference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying
22、the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently available valid International Standards. ISO 6879:1995, Air quality Performance characteristics and related concepts for air quality measuring methods. ISO 7934:1989, Stationary source e
23、missions Determination of the mass concentration of sulfur dioxide Hydrogen peroxide/barium perchlorate/Thorin method. ISO 7935:1992, Stationary source emissions Determination of the mass concentration of sulfur dioxide Performance characteristics of automated measuring methods. ISO 10396:1993, Stat
24、ionary source emissions Sampling for the automated determination of gas concentrations. ISO Guide25:1990, General requirements for the competence of calibration and testing laboratories. 3 Principle A representative sample of waste gas is extracted via a temperature-controlled probe, filtered and dr
25、awn through a hydrogen peroxide solution for a specified time and flow rate. The sulfur dioxide in the waste gas sample is absorbed by the solution and sulfate anions are formed. The mass concentration of sulfate in the absorption solution is subsequently determined using ion chromatography.BSISO116
26、32:1998 2 BSI 04-1999 4 Reagents During the analysis, use only reagents of recognized analytical grade. The sulfate-free water shall have an electrical conductivity of0,454m. Normal, accepted laboratory safety practices should be followed during reagent preparation. 4.1 Absorption solution,3% H 2 O
27、2 Pipette100cm 3of a27% (mole fraction) to30% (mole fraction) solution of hydrogen peroxide (H 2 O 2 ) into a 1000cm 3one-mark volumetric flask. Make up to the mark with water and mix well. Prepare this solution if possible on the day of use. 4.2 Eluent solution The choice of eluent depends on the m
28、anufacturers separator column and detector. For the exact composition of the eluent, refer to the instructions given by the manufacturer. NOTEFor an ion chromatograph using the suppressor technique, a typical eluent is a solution of1,7 10 3mol/l NaHCO 3and1,8 10 3mol/l Na 2 CO 3 . 4.3 Standard sulfa
29、te stock solution,10,4 10 3mol/l SO 4 2 Dissolve1,8141g of analytical grade potassium sulfate (K 2 SO 4 ) in reagent water and dilute to1l using a1000cm 3one-mark volumetric flask.1cm 3of stock solution corresponds to1mg of SO 4 2 . NOTEStandard sulfate stock solution is stable for at least28 days w
30、hen stored at277K. Calibration standards are prepared by diluting the standard stock solution with the absorption solution as specified in7.4.2. 4.4 Regeneration solution for suppressor For the exact composition of the suppressor regeneration solution, refer to the instructions given by the manufact
31、urer of the suppressor. NOTEAn example is a solution of12,5 10 3mol/l H 2 SO 4 . 5 Apparatus 5.1 Sampling equipment 5.1.1 General Alternative variations of the sampling equipment fulfilling the specified performance requirements for each component may be used. The performance characteristics set out
32、 in clause9 refer, however, to the examples of sampling equipment described in5.1.1 to5.1.16. It is important that all parts of the sampling equipment upstream of the first absorber are heated and that the components shall not react with or absorbSO 2 . NOTEIn special cases an unheated gas connector
33、 line may be used between the heated filter and first absorber, but this must be thoroughly rinsed with absorption solution after sampling and the washings combined with the sample. 5.1.2 Sampling probe The probe shall be of borosilicate glass or fused silica tube with a spherical ground joint at on
34、e end. Alternative probes of different lengths and inner diameters may be used, but the residence time of the sample gas in the probe shall be minimized. The sampling probe, which is surrounded by a heating jacket, shall be protected and positioned using a metal outer tube. A clamp screw shall be us
35、ed to adjust the probe length to reach the representative measurement point in the measurement plane of the waste gas duct. NOTEAn example of suitable probe dimensions is shown in Figure 1.BSISO11632:1998 BSI 04-1999 3 5.1.3 Filter holder The filter holder shall be of borosilicate glass or fused sil
36、ica glass with tube ends of spherical ground joints. The filter holder, which is encircled by the heating jacket, shall be connected to the sampling probe and housed within the protective metal tubing as shown in Figure 1. The temperature after the filter holder is verified using a thermocouple. NOT
37、E 1In special cases where the waste gas temperature is473K, the heating jacket around the sampling probe, filter holder and connector line may be omitted. The temperature in the sampling line before the first absorber, however, should not fall below the acid dew point temperature of the waste gas. N
38、OTE 2An example of suitable filter holder dimensions is shown in Figure 2. 5.1.4 Particle filter Alternative particle filters and filter holders of different designs may be used, but the residence time of the sample gas should be minimized. The filter material (quartz fibre or quartz wool packed pro
39、gressively) shall have an efficiency better than99,9%for particles of cut-off diameter0,64m for the actual sampling flow. NOTE 1An example of a suitable quartz-fibre particle filter of the “thimble” variety is shown in Figure 2. The filter is held in position in the filter holder by stainless steel
40、wire. NOTE 2In certain cases, a check on the possibility of a reaction between SO 2in the sampled gas and particles retained on the filter may be warranted. This can be performed by comparing sulfate analyses on the particle fractions obtained from (i) the filter used when sampling according to this
41、 International Standard, and (ii) particles obtained from another source at the site, e.g.cyclone. Figure 1 Positioning of sampling probe, filter holder and protective tubeBSISO11632:1998 4 BSI 04-1999 5.1.5 Absorbers Two absorption bottles with spherical ground glass joints and equipped with an abs
42、orption bottle insert having a sintered filter. Alternative absorber sizes and configurations may be used, provided that the absorption efficiency criteria specified in7.1 are met. NOTEAs an example, two125cm 3size absorption bottles of the Drechsel type with pore diameters in the sintered filter be
43、tween404m and904m may be used (see Figure 3). 5.1.6 Heating jacket Heating jacket or bandage capable of producing a temperature of at least473K. 5.1.7 Temperature regulator Temperature regulator suitable for use with the heating jacket or bandage. 5.1.8 Trap Absorption bottle equipped with an absorp
44、tion bottle insert not having a sintered filter. This bottle is connected after the second absorber and collects possible splashes of absorption solution. NOTEThe use of the trap is optional. 5.1.9 Drying tube Glass tube or absorption bottle packed with drying agent to dry the sample gas and protect
45、 the gas metering device and pump. NOTEAs an example, silica gel (1mm to3mm particle size) previously dried at448K for at least2h may be used. 5.1.10 Sampling pump Leak-free diaphragm pump capable of drawing sample gas at a flowrate within the range0,02m 3 /h to about 0,2m 3 /h during the sampling p
46、eriod against a pressure of10kPa to30kPa. A small surge tank between the pump and rotameter may be used to eliminate the pulsation effect of the diaphragm pump on the rotameter. Figure 2 Example of a particle filter and filter holderBSISO11632:1998 BSI 04-1999 5 5.1.11 Rotameter Flowmeter or rotamet
47、er capable of measuring the selected sample gas flow with limits of error2% of the upper limit of measurement. 5.1.12 Regulating valve Needle valve capable of adjusting the sample gas flowrate within the range0,02m 3 /h to0,2m 3 /h. 5.1.13 Gas metering device Dry-gas meter capable of use at a sample
48、 gas flowrate within the range0,02m 3 /h to about0,2m 3 /h, limits of error 2% of the measured volume, and equipped with a thermometer(5.1.14). 5.1.14 Connecting tubing Connecting tubing in a range of lengths and internal diameters. All parts of the sampling train upstream of the first absorber shal
49、l be of a material which does not react with or absorb SO 2 . The requirements are less stringent for parts of the sampling system downstream of the absorbers but corrosion resistant materials are recommended. NOTEExamples of convenient materials are borosilicate glass, fused silica and polytetrafluoroethylene (upstream of the absorbers) and polyethylene and silicone rubber (downstrean of the absorbers). 5.1.15 Thermometer Thermometer with measuring range268K to323K, limits of error2%of the upper limit of measurement.
