EN 1911:2010 – Stationary source emissions – Determination of mass concentration of gaseous chlorides expressed as HCl – Standard reference method

4 Principle
This European Standard describes the Standard Reference Method (SRM) for determining chloride ions content, expressed as HCl, emitting to atmosphere from ducts and stacks. The specific components and the requirements for the measuring system are described. A number of performance characteristics with associated minimum performance criteria are specified for the measuring system (see Tables 1 and 2 in 8.2).
These performance characteristics and the overall uncertainty of the method shall meet the specifications given in this European Standard. A known volume of flue gas is extracted representatively from a duct or a chimney during a certain period of time at a controlled flow rate with a heated probe. A heated filter removes the dust in the sampled volume, thereafter the gas stream containing gaseous chlorides is passed through a series of absorbers containing an absorption solution (chloride-free water).
All compounds which are volatile at the temperature of filtration and produce chloride ions upon dissolution during sampling are measured by this method, which gives therefore the volatile inorganic chlorides content of the waste gas. The results shall be expressed as HCI. 、After sampling the solutions are analysed by one of the following methods:
silver titration: potentiometric method (Method A);  mercuric-thiocyanate spectrophotometry (Method B);
ion-exchange chromatography (Method C).
5 Sampling
5.1 Sampling strategy
5.1.1 General The test programme shall be established following the advice and requirements described in EN 15259:2007 (5.4, Clauses 6, 7 and 8). a) Quantification of several compounds simultaneously, if relevant.
NOTE 1 Compounds such as gaseous chlorides, HF, SO 2 , NH 3 and water vapour, can be sampled simultaneously in parallel side stream lines.
NOTE 2 When performing isokinetic sampling the presence of water droplets means water vapour cannot be measured simultaneously in the same equipment.
b) Representativeness of the emission of the process. The following points shall be considered when preparing the sampling programme:
1) the nature of the plant process, e.g. steady state or discontinuous;
2) the homogeneity of the gas effluents at the sampling sections can be performed either by using an automatic HCl analyser or any other relevant surrogates gases (e.g. O 2 , CO 2 , etc.). When droplets are present, it is not necessary to perform the homogeneity test because a grid sampling is performed;
3) the expected concentration to be measured and any required averaging period, both of which can influence the measuring and sampling time. When a grid measurement is required, sampling time shall be in accordance with EN 13284-1 requirements related to the representativeness of the sample;
EN 1911:2010 – Stationary source emissions – Determination of mass concentration of gaseous chlorides expressed as HCl – Standard reference method