Overview

This document specifies a method for the determination of content of heavy extraneous materials larger than 3,15 mm by the use of sink-and-float separation combined with elutriation. This document is applicable to woody biomass in accordance with ISO 17225-1:2014, Table 1. Determination of content of heavy extraneous materials larger than 3,15 mm top size is important when evaluating the suitability of using biomass as biofuel. Stones and other impurities contained in biomass from stumps, roots, mill residue and harvest and landscape management residues may cause problems during size reduction, as well as during combustion. This method is designed to determine the level of impurities larger than 3,15 mm top size with a specific density >1 g/cm³ such as stones, glass, rubber, metal and certain types of plastics. During the processing of the sample, hand sorting of light impurities with a specific density ≤ 1 g/cm³ (for example, plastic foil) can also be done. Impurities smaller than 3,15 mm are not considered as part of this testing method but may still contribute to the ash content. The responsible German committee is Working Committee NA 062-05-82 AA "Biogene Festbrennstoffe" ("Solid biofuels") at DIN Standards Committee Materials Testing (NMP).

Document: references other documents

Responsible national committee

NA 062-05-82 AA - Solid biofuels  

Responsible european committee

CEN/TC 335 - Solid biofuels  

Responsible international committee

ISO/TC 238/WG 4 - Physical and mechanical test methods