ISO/TC 238/WG 6 - Sampling and sample preparation

This document describes simplified methods for taking samples of solid biofuels in small scale applications and storages including preparation of sampling plans and reports. The main focus is on storages with a size of ≤100 t. This document is applicable to the following solid biofuels: 1) fine (up to about 10 mm nominal top size) and regularly-shaped particulate materials that can be sampled using a scoop or pipe, e.g. sawdust, olive stones and wood pellets; 2) coarse or irregularly-shaped particulate materials (up to 200 mm nominal top size) that can be sampled using a fork or shovel, e.g. wood chips, hog fuel and nut shells; 3) large pieces (above 200 mm nominal top size) which are picked manually (e.g. firewood and briquettes). This document can also be used for other solid biofuels not listed above if the procedures described in this document are applicable. This document specifies methods to be used, for example, when a sample is to be tested for moisture content, ash content, calorific value, bulk density, mechanical durability, particle size distribution, ash melting behaviour and chemical composition. Additionally, it describes a method for the reduction of sample size and defines requirements on handling and storage of samples. NOTE 1 If higher precision of analytical results is needed or when in doubt if this document is applicable ISO 18135 can be used. Using the number of increments given in this document the resulting precision for analytical results can be estimated with the formulas given in ISO 18135. NOTE 2 Pellets can generate CO and CO2 off gasses by nature. If pellets are sampled, check for CO and CO2 and O2 levels prior and during the sample taking process in a confined space like a container, silo or shed and have another person standby at the entrance.

ISO 14780:2017 defines methods for reducing combined samples (or increments) to laboratory samples and laboratory samples to sub-samples and general analysis samples and is applicable to solid biofuels. The methods defined in this document can be used for sample preparation, for example, when the samples are to be tested for calorific value, moisture content, ash content, bulk density, durability, particle size distribution, ash melting behaviour, chemical composition, and impurities.

ISO 18135:2017 describes methods for preparing sampling plans and certificates, as well as taking samples of solid biofuels, for example, from the place where the raw materials grow, from production plant, from deliveries, e.g. lorry loads, or from stock. It includes both manual and mechanical methods, and is applicable to solid biofuels that are either: - fine (particle sizes up to about 10 mm) and regularly shaped particulate materials that can be sampled using a scoop or pipe, for example, sawdust, olive stones and wood pellets; - coarse or irregularly shaped particulate materials (particle sizes up to about 200 mm) that can be sampled using a fork or shovel, for example, wood chips and nut shells, forest residue chips, and straw; - baled materials, for example, baled straw or grass; - large pieces (particle sizes above 200 mm) that are either picked manually or automatically; - vegetable waste, fibrous waste from virgin pulp production and from production of paper from pulp that has been dewatered; - thermally treated and densified biomass materials; - roundwood. ISO 18135:2017 is not applicable to airborne dust from solid biofuels. It may be possible to use this document for other solid biofuels. The methods described in this document may be used, for example, when the samples are to be tested for moisture content, ash content, calorific value, bulk density, durability, particle size distribution, ash melting behaviour and chemical composition.