Synthesis of nitrogen-containing derivatives of alkenyl succinic acid and their functional properties in diesel fuels of different compositions

The study was aimed at synthesizing amides of different structures and their subsequent testing as paraffin dispersants in hydrotreated summer diesel fuels of different hydrocarbon compositions together with a depressor additive based on ethylene and vinyl acetate copolymer. The following parameters were determined for the hydrotreated base summer diesel fuels under study: molecular weight distribution of n-alkanes, fractional composition, density, kinematic viscosity, low-temperature properties, and sulfur content. The target compounds were synthesized using known procedures. Their structures were confirmed via infrared spectroscopy. For each product, the alkaline and acid numbers were determined using methods described in ASTM standards. The low-temperature parameters were estimated according to the known procedures given in ASTM standards, domestic state standards, as well as STO 11605031-041-2010 of the All-Russian Research Institute for Oil Refining. For the obtained diesel fuel samples, including those containing the additive, the following low-temperature properties were determined: pour point, cloud point, cold filter plugging point, as well as sedimentation stability under cold storage conditions. The amides synthesized in this work were found to improve the low-temperature properties of fuels depending on their alkenyl radical, as well as the composition of the analyzed diesel fuel; in particular, they increase the sedimentation stability under cold storage conditions. The article studied the dependence of the dispersing properties of synthesized amides on their structure and the molecular weight distribution of n-alkanes in the base summer diesel fuels.