Overview
EN ISO 18122:2022 - Solid biofuels: Determination of ash content is the CEN-adopted version of ISO 18122:2022. It specifies a standardized gravimetric method to determine the ash content of all solid biofuels. The method defines sample preparation, furnace conditions, apparatus and calculation steps so results are comparable across laboratories, suppliers and regulatory bodies.
Key topics and technical requirements
- Scope: Method applicable to all solid biofuels for reporting ash as the mass of residue after controlled combustion.
- Principle: Heat a defined test portion in air under controlled time, temperature and atmosphere; weigh residue to calculate ash content.
- Standard final temperature: 550 ± 10 °C is the reference. Alternative final temperatures (e.g., 710 °C, 815 °C) may be used if explicitly stated, but provided repeatability/reproducibility limits do not apply to those alternatives.
- Apparatus requirements:
- Dish of inert material (porcelain, silica or platinum) sized so test portion loading does not exceed 0.1 g/cm of bottom area.
- Furnace with uniform heating and sufficient air exchange to remove decomposition gases (SO2, CO2) during ashing.
- Analytical balance capable of reading to 0.1 mg.
- Desiccator with controlled desiccant (ash is very hygroscopic - lids recommended and desiccant must be monitored/dried).
- Sample preparation and conditioning: Laboratory sample and general analysis sample prepared per ISO sampling/sample-prep requirements; nominal particle top size ≤ 1 mm. Ash testing can be performed directly on the general analysis sample or on a dried test portion with concurrent moisture determination (ISO 18134-3).
- Automatic equipment: Permitted if validated with appropriate biomass reference materials and meeting method constraints for sample size, heating profile, atmosphere and weighing.
- Performance data: Clause 9 provides repeatability and reproducibility figures; this edition updated those data and gives more detailed furnace and ashing procedure descriptions.
Applications - who uses this standard
- Testing laboratories performing quality control and certification of solid biofuels.
- Bioenergy producers and fuel suppliers for contract verification and inventory reporting.
- Combustion equipment manufacturers and operators to assess ash-related risks (slagging, corrosion) and design maintenance schedules.
- Regulators and procurement teams setting fuel specifications and environmental compliance.
- Researchers studying biomass combustion and ash behaviour.
Related standards
Keywords: EN ISO 18122:2022, ash content determination, solid biofuels, ashing procedure, biofuel testing, furnace conditions, sample preparation, repeatability reproducibility.