Influence of Group Hydrocarbon Composition of Diesel Fuels on Depressant Additive Efficiency

The physicochemical properties of nine summer base diesel fuels were compared. The influence of the group hydrocarbon composition on the low-temperature properties was examined using two fuels with similar physicochemical properties as examples. The physicochemical characteristics of the fuel were shown not to be definitive, rather, its detailed group chemical composition reflecting the molecular-mass distribution of n-alkanes and ratio of mono-, bi-, and polycyclic aromatic hydrocarbons that affect the injectivity of the fuel additives was important. A study of the cold filter plugging point and pour point of these fuels in the presence of two depressant additives based on ethylene-vinyl acetate copolymers showed that additive 1 exhibited more universal properties in fuels differing in group chemical composition while additive 2 reduced effectively the cold filter plugging point in fuels with lower contents of high-melting n-alkanes and exhibited pour point depression comparable to that of additive 1 in fuels with high contents of this hydrocarbon group.