ISO 16861:2015

Overview

ISO 16861:2015 specifies international requirements and test methods for dimethyl ether (DME) used as a fuel (F-class). The standard covers DME whose main component is synthesized from any organic feedstock and defines composition, impurity limits, sampling and test-method references for DME used as heating fuel, industrial fuel and as a substitute for diesel/gas oil. ISO 16861:2015 does not address end‑use additives (for example odorants or lubricity improvers), which are specified separately as required.

Key topics and technical requirements

• DME purity: minimum 98.5% (mass) (purity is calculated from measured impurities per clause 5.1).
• Maximum impurity limits (mass % unless stated):
  • Methanol ≤ 0.050%
  • Water ≤ 0.030%
  • Hydrocarbons (up to C4) ≤ 1.00%
  • Carbon dioxide (CO2) ≤ 0.10%
  • Carbon monoxide (CO) ≤ 0.010%
  • Methyl formate ≤ 0.050%
  • Ethyl methyl ether ≤ 0.20%
  • Evaporation residues ≤ 0.007%
  • Total sulfur ≤ 3.0 mg/kg
• Sampling: Representative sampling at terminals is specified by ISO 29945.
• Test methods: Impurity and property determinations reference established ISO test standards such as ISO 17196, ISO 17197, ISO 17198, ISO 17786, etc.
• Informative Annex: Annex A provides physical properties of DME (boiling point, density, vapor pressure, calorific values) useful for handling and system design but not part of the commercial specification.

Applications and practical value

• DME covered by ISO 16861:2015 is suitable for:
  • Domestic and commercial heating fuel
  • Industrial boilers and process heating
  • Replacement fuel for diesel/gas oil in compression‑ignition applications (requires lubricity/additives as appropriate)
• Practical benefits:
  • Provides a consistent quality baseline for producers, traders and buyers of DME fuel
  • Facilitates international trade, regulatory compliance and interoperability of fuel systems
  • Supports safety, equipment specification and emissions considerations by clarifying allowable impurities and sulfur content

Who uses this standard

• DME producers and refiners
• Fuel distributors, terminal operators and traders
• Testing laboratories and inspectors
• Engine, burner and boiler manufacturers
• Fleet operators, utilities and regulators establishing fuel procurement or compliance criteria

Related standards

• ISO 17196:2014 - DME impurity analysis (GC)
• ISO 17197:2014 - Water by Karl Fischer
• ISO 17198:2014 - Total sulfur (UV fluorescence)
• ISO 17786:2015 - Evaporation residue at 105 °C
• ISO 29945 - Manual sampling of refrigerated non‑petroleum gaseous fuels (DME)

Keywords: ISO 16861:2015, dimethyl ether (DME) specifications, DME fuel standard, DME purity, DME properties, fuel standards, DME for diesel replacement.