PRODUCTION OF FUELS WITH IMPROVED ENVIRONMENTAL AND OPERATIONAL PROPERTIES BY BLENDING SYNTHETIC AND CONVENTIONAL FUELS AND INVESTIGATION OF THEIR PHYSICOCHEMICAL PROPERTIES

This study investigates the development of environmentally improved diesel fuels through blending synthetic Gas-to-Liquids (GTL) fuel with conventional diesel fuel and gas oil fractions. The objective was to determine how blend composition influences key physicochemical, operational, and environmental properties and to identify formulations suitable for practical use under EURO K4 requirements. Experimental blends were prepared by mechanical mixing at different volume ratios under laboratory conditions. Their cetane number and index, density, distillation behavior, kinematic viscosity, flash point, cold filter plugging point, sulfur content, polycyclic aromatic hydrocarbon content, oxidation stability, total contamination, copper-strip corrosion, and lubricity were determined using ASTM, EN, GOST, and O‘zDSt standard methods.

The results showed that increasing the proportion of GTL significantly improved ignition quality and environmental performance. Blends containing 50–60% GTL achieved cetane numbers of 62–63, densities of 791.2–796.1 kg/m³, and kinematic viscosities of 3.27–3.33 mm²/s. Their sulfur content decreased to 9.4–17.2 mg/kg, while polycyclic aromatic hydrocarbons were reduced to 2.9–3.8%. The cold filter plugging point reached −10 to −11 °C, indicating satisfactory low-temperature operability. Distillation characteristics also confirmed a favorable balance between volatility and complete combustion.

Overall, the study demonstrates that GTL-based blending is an effective approach for producing cleaner and more efficient diesel fuels. The optimized blends provide improved combustion stability, lower pollutant-forming components, acceptable lubricity, and reliable operation under low-temperature conditions, supporting their potential application in modern diesel engines