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