The 873 Biodiesel Rancimat is a modern, PC-controlled instrument for the convenient determination of the oxidation stability of oils and fats
Oxidation stability of biodiesel is an essential test according to EN 14214.
Blends of biodiesel and petrochemical diesel ideally also need testing as they are the dominant market.
Metrohm says it has perfected accessories for the Biodiesel Rancimat to measure blends.
The manufacture and use of fatty acid methyl esters (Fame), has huge implications for the environment.
Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources.
Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend.
It can be used in compression-ignition (diesel) engines with little or no modifications.
Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulphur and aromatics.
Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil.
The process leaves behind two products - methyl esters (the chemical name for biodiesel) and glycerin (a valuable byproduct usually sold to be used in soaps and other products).
Fuel-grade biodiesel must be produced to strict industry specifications (EN14214).
Most commercially available biodiesel fuels are actually biodiesel blends that are properly referenced with the letter B followed by a one- or two-digit number that represents the percentage of biodiesel used in the blend with petroleum diesel fuel.
Pure biodiesel is sometimes called 'neat' biodiesel and is also referred to as B100.
The most common biodiesel blends are B2, B5, B10, B20 and B50.
The remaining fraction is petroleum-based diesel fuel, which is often referred to as petrodiesel.
Vegetable oils and fatty acid methyl esters have a relatively short storage life as they are slowly oxidised by atmospheric oxygen.
The resulting oxidation products can damage vehicle motors.
For this reason the oxidation stability is an important quality criterion for biodiesel and vegetable oils and must therefore be checked regularly during manufacture and storage (EN 14112).
With the 873 Biodiesel Rancimat, this determination can be carried out simply and reliably.
The addition of suitable antioxidants slows down the oxidation process.
The effectiveness of antioxidants can also be determined with the 873 Biodiesel Rancimat.
The temperature can be set very accurately and reproducibly by using the GLP Set with certified temperature sensor; this further improves the precision of the results.
The latest revision of the oxadation stability standard EN 14112 will also include specifications of determining the stability in not only biodiesel but also blends of biodiesel and petrochemical diesel and even just petrochemical diesel.
Metrohm says it has managed to perfect the methodology by increasing the reaction tube lengths and changing some method parameters.
As mainly biodiesel blends are sold, assessing the stability of these blends as well as neat biodiesel provides more meaningful and representitive assessment of fuel quality In summary, measuring oxidation stability of biodiesel is essential as stated by EN 14214 and EN 14112 as degraded fuels will cause numerous engine problems.
Metrohm have perfected the means to test blends of biofuels which provides a more realistic assessment of fuels for the current market.
