Investigation of storage stability of biodiesels

Abstract

The production and application of fuels from agricultural origin have emerged into focus in the last couple of years. A number of environmental, political and economical factors has confirmed and strengthened this process. The main reason of this tendency is the energy policy of the European Union, namely to reduce the green house gas emission of fuels, to decrease the significant dependence of EU on import energy and crude oil and to support rural development. To achieve these objectives, the European Union created the 2003/30/EC and 2009/28/EC directives, which regulate the application of biomass derived fuels. The main purpose is to promote the use of biofuels in transportation by recommending and specifying the share of the bio-components. This proposed value (10 energy % share of biofuels in the transport sector by 2020 in the EU) can be reached by the conversion of different triglyceride-containing biofeedstocks (e.g. vegetable oils, used frying oils, animal fats, algae oils, brown grease, etc.) to different biofuels orblending components. Nowadays FAME (Fatty Acid Methyl Esters), called as first generation biofuel, is mostly used as diesel bio blending component. But this biofuels due to its chemical structure the presence of the double bond in the molecule have a high reactivity with the oxygen, especially when it placed contacting air. That is why the long term storage stability of biodiesel is an important issue. The aim of our research work was to investigate the long term storage stability of biodiesel samples originated from different feedstock. The effects of the real storage conditionson the properties (induction period, acid value, iodine value, density, water content and kinematic viscosity) of the different biodiesels were investigated. Results showed that the acid number and the water content increased, while the induction period and the iodine number decreased with increasing storage time of biodiesel samples.