ISO 16967:2015

Overview

ISO 16967:2015 - Solid biofuels - Determination of major elements - Al, Ca, Fe, Mg, P, K, Si, Na and Ti defines wet-chemical methods for measuring major elemental constituents in solid biofuels and/or their ashes. The standard is published by ISO and is organized in two parts: Part A specifies direct determination on the fuel, while Part B covers determination on a prepared 550 °C ash. Methods support detection by ICP-OES, ICP-MS, FAAS, and FES and can also be used to quantify other elements (e.g., Ba, Mn).

Key topics and technical requirements

• Scope of elements: Aluminium (Al), Calcium (Ca), Iron (Fe), Magnesium (Mg), Phosphorus (P), Potassium (K), Silicon (Si), Sodium (Na), Titanium (Ti).
• Two analysis routes:
  • Part A - direct closed-vessel digestion of the fuel (also applicable to sulfur and minor elements).
  • Part B - analysis of a 550 °C prepared ash (ensures reproducible ash matrix).
• Digestion reagents and safety: Uses analytical-grade reagents such as HNO3, H2O2, HF (with HF safety warning), and boric acid for HF neutralization.
• Representative procedure (Part A): Example protocol uses 500 mg sample with 3.0 ml H2O2 (30%), 8.0 ml HNO3 (65%) and 1.0 ml HF (40%) in a closed vessel; heating programs are specified for resistance and microwave digestion and for post-digestion HF neutralization.
• Detection & calibration: Element detection by ICP-OES/ICP-MS/FAAS/FES; calibration must use certified reference materials (CRM/SRM) and include blank tests and performance verification.
• Quality controls: Use of CRMs (e.g., NIST SRMs) to verify accuracy; report performance characteristics and calculation conventions.

Applications and who uses it

• Laboratories performing compositional analysis of biomass fuels.
• Power plants and co-firing facilities assessing ash behavior, slagging/fouling risk and corrosion potential.
• Biofuel producers and feedstock suppliers for quality control and contamination checks (soil/sand or process additives).
• Researchers and regulatory bodies studying elemental balance, ash utilization, or complying with fuel standards. Practical outcomes include improved combustion performance, ash management strategies, and informed decisions on blending and pretreatment.

Related standards

• EN 14780 (sample preparation)
• ISO 18122 (ash content, ashing procedure)
• ISO 18134-3 (moisture determination)
• ISO 16559 (terminology)
• ISO 11885 / ISO 17294-2 (ICP-OES / ICP-MS methods)

Keywords: ISO 16967:2015, solid biofuels, major elements, ash analysis, ICP-OES, ICP-MS, FAAS, FES, HF digestion, certified reference material.