The software of this third Rancimat generation comprises automatic data acquisition and evaluation as well as a database and permits the easy management of large amounts of data
The 873 Biodiesel Rancimat is the latest generation in oxidation stability analysers from Metrohm.
It is a modern, PC-controlled instrument for the convenient determination of the oxidation stability of biodiesel and biodiesel blends (mixtures of biodiesel and conventional diesel fuel) as per EN 14 112.
Disposable reaction vessels minimise cleaning requirements.
This saves both time and money and the accuracy and reproducibility of the measurements are also significantly improved from the older instruments when glassware had to be re-used.
The GLP Set with certified temperature sensor allows you to set the temperature very accurately and reproducibly, which in turn improves the precision of the results.
Oxidation stability of biodiesel (fatty acid methyl esters, Fame and biodiesel blends.
The use of alternative fuels from renewable plant sources has become increasingly widespread in recent years and will continue to increase considerably in the future.
There are several reasons for this, among them the following:.
Fossil fuel deposits are limited, which makes economic use of these resources imperative - biodiesel is obtained from renewable raw materials.
The combustion of biogenic fuels is CO2-neutral.
The carbon dioxide released from them has previously been assimilated from the atmosphere during the growth phase of the plants.
In contrast to CO2 from fossil fuels, it makes no contribution to the enrichment of carbon dioxide in the atmosphere and the resulting atmospheric warming.
Alternative fuels can often be produced locally and this reduces dependence on imported raw materials.
Alternative fuels are usually very easily biodegradable and therefore cause less environmental damage, particularly when used in ecologically sensitive areas.
In addition to other alternative fuels such as ethanol, methanol or biogas (methane), fatty acid methyl esters are increasingly found on the market; these are then known as biodiesel, RME (rapeseed oil methyl esters) or Fame (fatty acid methyl esters).
Fatty acid methyl esters are usually obtained from oil seeds and are mainly used in their pure form or mixed with conventional diesel fuel in the transport sector.
Biodiesel is usually produced from vegetable oils, but animal fats can also be used.
The vegetable oil is transesterified with methanol.
This produces the methyl esters of the fatty acids present in the oil together with glycerol as a byproduct.
Fatty acid methyl esters are relatively unstable on during storage as like all natural oils and fats they are slowly oxidized by atmospheric oxygen.
The substances produced from oxidation can cause engine damage.
This is why oxidation stability is an important quality criterion for biodiesel; it is regularly determined during the production process.
With the 873 Biodiesel Rancimat this determination can be carried out quickly and simply.
The oxidation process can be delayed by the addition of antioxidants.
The 873 Biodiesel Rancimat can also be used to determine the effectiveness of antioxidants.
This opens up a further field of application for the instrument.
During the measurement a stream of air is passed through the sample which is contained within a sealed and heated reaction vessel.
These conditions accelerate the rate of oxidation of the fatty acid methyl esters in the sample, with peroxides being initially formed as the primary oxidation products.
After some time the fatty acid methyl esters disintegrate completely; the second oxidation products formed include low-molecular organic acids in addition to other volatile organic compounds.
These are transported in a stream of air to a second vessel containing distilled water.
The conductivity in this vessel is recorded continuously.
The organic acids can be detected by the increase in conductivity.
The time elapsed until these secondary reaction products appear is known as the induction time or induction period.
