B20 Fuel Compatibility with Steels in Case of Fuel Contamination

Abstract

This study evaluated the compatibility with steels for three B20 fuel samples blended from fossil diesel and used cooking oil methyl ester. One sample was untreated and its concentration of copper was analyzed as <1 ppm. Another sample was doped by adding Cu at a concentration of ≤2 ppm and the third sample by adding Cu at a concentration of ≤4 ppm. Steel samples (carbon steel, stainless steel and a special alloy) were then put into the fuel blends and stored at 50 °C for 692 h. After storing, the metal concentrations of the fuel blends were again analyzed, and signs of corrosion were evaluated visually. The aim of this study was to find out if the fuel already contaminated by copper will affect the corrosion of the chosen steel qualities. Additionally, fuel properties were measured for all three blend samples before the immersion of steels. Visual evaluation of the steels indicated that signs of corrosion were seen in all studied samples, but Cu doping did not increase the signs of corrosion notably. The results also showed that the copper content from 1 to 2 and 4 ppm reduced the oxidation stability and increased the acid number of the fuel samples.

Effects of Fuel Hydrochloric Acid Contamination on Selected Metals

“…Copper could be the reason why these fuel samples had a slightly lighter color change than the fuel samples that contained stainless steel and CrMo tempering steel. This finding is supported by the study by Sirviö et al [37], who found that biodiesel-diesel blends containing copper changed color.…”

“…After carbon steel immersion, copper was found in the pure diesel, hydrochloric acid-diesel samples, and the water-diesel sample. In previous studies where carbon steels were immersed in B20 fuel blends, it was also noticed that copper was dissolved [37,39]. It seems that copper is easily leached from carbon steel samples.…”

“…Al-Abdullah et al [36] studied different diesel-gasoline blends, and they noticed that just one volume percent of gasoline in the blend decreases the flash point when compared to pure diesel. Sirviö et al [37] established that 2 ppm and 4 ppm copper contaminants weakened the oxidation stability of B20 biodiesel-diesel blends. Selim et al [38] made water-in-diesel fuel emulsions with different water contents, identifying adverse effects on properties including viscosity and density.…”