Changes in Physical and Chemical Characteristics of Biodiesel Fuel and Its Compositions During Storage
Year: 2022
Type: article
Abstract: Alternative fuels, primarily synthesized from renewable plant materials, are becoming increasingly important. The standards that regulate the characteristics of modern environmentally friendly diesel fuel allow the addition of 6 to 20% of biodiesel fuel synthesized from renewable plant or animal feedstock to petroleum fuel. This additive allows not only to reduce the emission of harmful substances with exhaust gases, but also to increase the cetane number and lubricity of modern fuels with a low content of sulfur and aromatic compounds. The changes in physicochemical characteristics that occur during storage of biodiesel fuel have been studied on the example of biodiesel fuels synthesized from camelina and flax oils. It is shown that the density and viscosity of biodiesel fuel increase during storage in polyethylene and metal tanks, and to a greater extent during storage in a metal tank. It has been established that the viscosity (3.5-5.0 mm2 /s) and density (860-900 kg/m3 ) of biodiesel fuel is stored within the normalized limits for 7 months in a polyethylene tank; and the shelf life is reduced to 4-5 months in metal tank. The reason for the deterioration of fuel quality are oxidation and polymerization processes. Additives belong to a homologous series of sterically hindered phenols containing an azo group have been proposed for stabilization. Studies of the storage process of compositions of petroleum and biodiesel fuels containing from 10 to 70% (vol.) of the latter (B10 - B70) have been carried out. It has been established that stratification of fuel compositions occurs in addition to an increase in density and viscosity during storage. In this case, compositions with a low content of biodiesel fuel are stratified first. 50% and 40% of biodiesel fuel flaked off in compositions B10 and B20, respectively, for 5 months; the process began already after 30 and 60 days of storage. In composition B50, stratification started only after 4 months of storage; only 4% of the biodiesel fuel flaked off by the end of the fifth month. No stratification was observed for composition B70. The stratification may be due to weak intermolecular interactions between petroleum hydrocarbons and biodiesel molecules containing polar ester groups; as well as with the destruction of the colloidal structure of fuels.
Source: SCIENCE IN THE CENTRAL RUSSIA
Language: English
Subfield: Fuel Technology
Field: Energy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4312371185