EN ISO 18125:2017 PDF

Overview

EN ISO 18125:2017 - Solid biofuels: Determination of calorific value (ISO 18125:2017) defines a standardized laboratory method to determine the gross calorific value of solid biofuels using a bomb calorimeter. The procedure specifies measurements at constant volume and at the reference temperature 25 °C, using a bomb calorimeter calibrated by combustion of certified benzoic acid. The standard is published as EN ISO 18125:2017 and supersedes EN 14918:2009.

Key topics and technical requirements

• Principle and scope
  • Determination of gross calorific value (higher heating value) at constant volume with combustion water considered as liquid.
  • Conversion to net calorific value (lower heating value) at constant pressure is addressed with provided formulae.
• Calibration
  • Mandatory calibration using certified benzoic acid; calculation of the calorimeter’s effective heat capacity (ε) and valid working range.
• Apparatus and reagents
  • Requirements for bomb calorimeters and reagents used in calibration and combustion experiments.
• Test procedure
  • Sample preparation, bomb assembly, use of combustion aids, combustion, temperature measurement and corrections, and analysis of combustion products.
• Instrument-specific guidance
  • Annex A–C: procedures for adiabatic, isoperibol/static-jacket, and automated bomb calorimeters.
• Quality control and reporting
  • Checklists (Annex D), worked calculation examples (Annex E), performance characteristics (repeatability and reproducibility limits), and test report content.
• Supporting material
  • Annex F–H include symbols, default values for common solid biofuels, and a flow chart for routine determinations.

Practical applications and users

• Who uses ISO 18125:2017:
  • Test laboratories performing calorific value determinations for compliance, trade and quality control.
  • Biofuel producers and suppliers verifying energy content of pellets, wood chips, agricultural residues and other solid biofuels.
  • Equipment manufacturers of bomb calorimeters implementing calibration and verification protocols.
  • Regulators and certification bodies assessing fuel standards, energy labeling and contractual specifications.
  • Research institutions studying fuel properties and combustion behavior.
• Practical benefits:
  • Ensures consistent, traceable energy content measurements for billing, fuel specification, emissions modeling and boiler/furnace design.
  • Provides standardized conversion to net calorific values to reflect real operating (atmospheric pressure) conditions.

Related standards

• EN 14918:2009 - superseded by EN ISO 18125:2017 (see standard text for transition and equivalence).
• Developed by ISO/TC 238 (Solid biofuels) and adopted by CEN as EN ISO 18125:2017.

Keywords: EN ISO 18125:2017, ISO 18125:2017, solid biofuels, calorific value, gross calorific value, net calorific value, bomb calorimeter, calorimeter calibration, biofuel testing.