Development of Biodiesel Standard Reference Materials

The National Institute of Standards and Technology (NIST), USA and the National Institute of Metrology, Standardization, and Industrial Quality (INMETRO), Brazil are collaborating on the development of Certfied Reference Materials (CRMs) for biofuels. INMETRO is developing two bioethanol CRMs, and NIST is developing two biodiesel CRMs, Standard Reference Material (SRM) 2772 B100 Biodiesel (Soy-Based) and SRM 2773 B100 Biodiesel (Animal-Based). Biodiesel is an alternative fuel produced by the transesterification of triglycerides of vegetable oils or animal fat with methanol to form the fatty acid methyl esters. Since some of the by-products, if not separated, can cause engine problems, it is important to have reliable concentrations for glycerol, mono- and diglycerides, unreacted triglycerides, and fatty acid methyl esters. The biodiesel industry within the USA is increasing at a fast pace, and the industry needs reference materials to benchmark the measurements not only of the fatty acid methyl esters and glycerides but also for sodium, potassium, calcium, magnesium, sulfur, phosphorous, moisture, density, and viscosity. NIST and INMETRO have provided data for the parameters that they developed methods for in these two SRMs. The data have been combined to provide certified concentration values for fatty acid methyl esters, water, sulfur, and kinematic viscosity; reference concentration values for additional fatty acid methyl esters, free glycerol, and additional physical properties; and information values for other trace elements, mono-, di-, and triglycerides, and total glycerol. The development and certification of these biodiesel SRMs will be discussed.