ISO 19743:2026

Overview

ISO 19743:2026 establishes a standardized method for determining the content of heavy extraneous materials (HEM) larger than 3.15 mm in solid biofuels. The method relies on sink-and-float separation combined with elutriation. This standard is specifically targeted at woody biomass, particularly hogfuel, and helps ensure the safe and efficient use of solid biofuels in accordance with ISO 17225-1 and ISO 17225-9. By quantifying heavier contaminants with density over 1 g/cm³-such as stones, glass, rubber, metal, and certain plastics-ISO 19743 supports quality assurance, plant safety, and optimized biofuel performance.

Key Topics

• Purpose: Assessing levels of impurities that can adversely affect energy output, equipment longevity, and operational costs in biofuel processes.
• Applicable Materials: Woody biomass types, such as wood chips and hogfuel, as defined by ISO 17225 series.
• Contaminant Types: Heavy materials (>3.15 mm and >1 g/cm³)-including stones, glass, metals; manual removal of certain lighter impurities is also considered.
• Sample Preparation: Guidelines for representative sampling, sample handling, and preparation referencing ISO 14780 and ISO 18135.
• Separation Method: Utilizes the principles of sedimentation and elutriation in water to differentiate between biogenic and non-biogenic particles.
• Verification: Drying and weighing procedures help determine HEM content on a percentage dry weight basis, promoting process accuracy.
• Test Reporting: Clear requirements for documenting results, including test conditions and any deviations, to support traceability and data integrity.

Applications

• Biofuel Production: Ensures the feedstock quality for biomass and pellet plants by identifying damaging or energy-reducing contaminants.
• Power and Heat Generation: Helps prevent damage to combustion and milling equipment, minimizing maintenance downtime and operational risk in facilities using biomass fuels.
• Quality Control Laboratories: Provides a consistent, reference method for labs to certify biofuel batches or investigate fuel quality issues.
• Regulatory Compliance: Supports conformity with international and national environmental or quality requirements for bioenergy products.
• Supplier and Procurement Management: Enhances supplier evaluation processes and raw material acceptance, enabling industry stakeholders to enforce stringent specifications.

Related Standards

• ISO 17225-1:2021: Solid biofuels - Fuel specifications and classes - General requirements. Specifies the range of woody biomass types for which ISO 19743 can be applied.
• ISO 17225-9:2021: Solid biofuels - Graded hog fuel and wood chips for industrial use. Defines detailed fuel classes particularly relevant for this HEM determination.
• ISO 14780: Sample preparation for solid biofuels. Guides representative sampling and handling protocols.
• ISO 18134-1 / ISO 18134-2: Methods for the determination of moisture content in solid biofuels, critical for accurate HEM percentage calculation.
• ISO 3310-2: Test sieves of perforated metal plate. Specifies sieve characteristics for the mechanical separation aspects of the method.

ISO 19743:2026 plays a vital role in advancing biofuel quality management and operational safety. By adhering to this standard, bioenergy producers, laboratories, and plant operators can reliably detect and quantify heavy extraneous materials, ensuring efficient, safe, and sustainable bioenergy production.

For further guidance and technical documentation, refer to the full ISO 19743:2026 text available from iso.org.