Metrology for Biofuels

The EU’s Fuel Quality Directive (2009/30/EC) sets out the quality and sustainability criteria for biofuels. Therefore liquid biofuels from a range of sources with different characteristics need to be accurately measured and monitored during production, storage, transportation and distribution. In addition, sustainable development policies also require ‘trackability’ of biofuels in terms of their biological and geographical origin.

This EMRP project focused on liquid biofuels used in the automotive sector. It developed a measurement infrastructure that not only provides reliable data but can rapidly adapt to different types and origins of biofuels.

The project developed:

• Reference methods for chemical parameters at NMIs to identify and quantify methanol, glycerol, glycerides and selected Fatty Acid Methyl Esters (FAME) content of biodiesel in line with the requirements of European standards. These reference methods ensure that measurements made in testing labs are traceable to national standards and therefore reliable and comparable.
• Accurate data, traceable to the SI, for key physical parameters of a range of typical biofuels (density, viscosity, calorific value and state behaviour at high temperatures and pressures). These data enable accurate determination of the volume and energy content for biofuel trade in line with legal requirements and support process control in biofuel production and optimised design of engines using biofuels.
• Reference measurement methods and reference data for two important biofuel quality indicators – the pH value of bioethanol and electrolytic conductivity. These indicators are used to assess the risk of corrosion and potential damage to engines using biodiesel. The methods developed have provided data traceable to the SI for the first time.
• A successful feasibility study of analytical methods for origin discrimination of biofuels including geographical origin, production method and source materials.

Delivering impact

The project has put in place the metrology infrastructure to enable European and international harmonisation of the measurement methods of biofuels and their blends with fossil fuels. Internationally comparable quality standards and a wider knowledge of properties of biofuels is enabling further technical developments in their use as an automotive fuel and facilitates greater acceptance from customers and vehicle manufacturers. More generally the development of references for chemical and physical parameters provides confidence in international quality assurance of biofuels and facilitates global trade.

The project’s results have been shared with the relevant ISO and CEN Technical Committees (TCs) – CEN TC 19 Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin and ISO TC28 Petroleum products and related products of synthetic or biological origin – and have contributed to the draft of a new standard on ethanol test methods under ISO TC28/SC7/WG4.