The Comité Européen de Normalisation (European Committee for Standardization), or CEN, published a technical specification in 2006 that deals with the determination of biogenic carbon content in solid recovered fuels. CEN/TS 15440:2006 outlined three methods: selective dissolution method, manual sorting, and the reductionistic method.
CEN Working Group 343, responsible for creating standards for SRF, published EN 15440:2011, a revised version of the 2006 document. The EN 15440 standard no longer includes the reductionistic method and specifies 3 methods based on carbon-14 analysis for determining the biomass or biogenic carbon content of SRF. The carbon-14 content of SRF can be measured via Proportional Scintillation Method (PSM), Beta Ionisation (BI), or Accelerated Mass Spectrometry (AMS). EN 15440 also includes an example of how to convert the biogenic carbon content to biomass energy.
EN 15440 recommends three methods to determine the biomass fraction of mixed wastes:
1. Selective Dissolution Method (SDM) – based on the reaction of biomass in a mixture of sulfuric acid and hydrogen peroxide. The method is not appropriate if the SRF sample has biomass components that are insoluble in sulfuric acid or fossil-based components that are soluble in the acid.
According to EN 15440, SDM must not be applied if the following materials are contained at levels above 5%: solid fuels (e.g. hard coal, coke, brown coal, lignite and peat), charcoal, biodegradable plastics of fossil origin, non-biodegradable plastics of biogenic origin, oil or fat present as a constituent of biomass, natural and/or synthetic rubber residues, wool, viscose, silicon rubber, or nylon, polyurethane or other polymers containing molecular amino groups. For rubber residues, the threshold is 10%.
2. Manual Sorting – This method entails visual inspection, thus it is ineffective when the SRF components are shredded finely or compressed. It is only applicable to materials with a particle size greater than 10 mm and where optically and physically distinguishable fractions can be separated and quantified.
3. Carbon-14 Method – This method measures the radiocarbon content of the mixed wastes and is applicable to all materials.
Page last updated: August 2023