ISO 16994 describes methods for the determination of the total sulfur and total chlorine content in solid biofuels.
ISO 16994 specifies two methods for decomposition of the fuel and different analytical techniques for the quantification of the elements in the decomposition solutions.
The use of automatic equipment is also included in ISO 16994, provided that a validation is carried out as specified and that the performance characteristics are similar to those of the method described in ISO 16994.
ISO 16994 on Determination of total content of sulfur and chlorine is useful for:
Sulfur and chlorine are present in solid biofuels in varying concentrations. During the combustion process, they are usually converted to sulfur-oxides and chlorides. The presence of these elements and their reaction products can contribute significantly to corrosion and to environmentally harmful emissions.
Chlorine can be present in different organic and inorganic compounds and is to exceed or equal the water soluble amount that can be determined by ISO 16995.
Combustion in an oxygen atmosphere in a closed combustion vessel is the preferred method to digest biomass samples for a determination of the total content of sulfur and chlorine. An advantage of the method is that the digestion can be carried out in connection with the determination of the calorific value according to ISO 18125. Decomposition in closed vessels is an appropriate alternative method.
Other analytical techniques (e.g. high-temperature combustion in a tube furnace and Eschka method) may also be used. The determination of the resultant chlorine and sulfur compounds can be done by different techniques, e.g. ion chromatography, ICP, titrimetry.
Automatic equipment and alternative methods may be used when these methods are validated with biomass reference samples of an adequate type and also meet the requirements of Clause 10.
ISO 16994 provides guidance on the determination of the total content of sulfur and chlorine in solid biofuels, which helps reduce harmful environmental emissions and protection against corrosion.
Note: A list with typical sulfur and chlorine contents of solid biofuels can be found in ISO 17225-1:2014, Annex B.
EN ISO 16994 (ISO 16994:2016) AS
ISO 16994:2016