Influence of malonik acid monoamides on the thermal-oxidating stability of dieseln fuel

Abstract

To improve environmental standards from diesel fuels (DF), it is necessary to remove sulfur and nitrogen-containing heterocyclic compounds, which leads to a decrease in oxidative stability, since sulfur and nitrogen compounds are natural antioxidants and help to inhibit the oxidation process of diesel fuel. This article discusses the effective and promising antioxidants synthesized by us for hydrotreated diesel fuel. For this purpose, monoamides of malonic acid (MA) were synthesized; malonic acid and aliphatic amines (from butyl to nonylamine) of various structures were taken as starting compounds. Their structures were studied by IR spectroscopy. Their physicochemical properties have also been studied. With the addition of 0.004 % of the synthesized malonic acid monoamides to hydrotreated diesel fuel, compositions were prepared that were oxidized at 120 oC for 4 hours on an LSART apparatus. It has been established that, compared with the hydrotreated diesel fuel itself, monoamides of MA reduce precipitation by 2–45 times, and compared with the known ionol, MA monoamides have better performance, for example, with the addition of MA monobutylamide, precipitation decreases from 4.5 mg/100 ml to 0.5 mg/100 ml, and monoisobutylamide reduces to 0.1 mg/100 ml. Thus, monoamides of MA can be proposed as antioxidants for hydrotreated diesel fuel due to their high antioxidant properties.