Effect of desulfurization of diesel and its blends with biodiesel on metallic contact

Abstract

The current environmental scenario has required changes in fuel nature, in order to minimize the harmful effects caused by sulfur in diesel. However, reductions in sulfur content promote loss of its lubricity and consequently wear in the injection system of the diesel engine. This study aimed to investigate the influence of sulfur minimization on fuel lubricity and wear of metallic disks. The fuel tribological analysis was carried out in HFRR equipment in accordance with ASTM D 6079-04. The tested fuels were diesel oil with 50, 500 and 1800 ppm sulfur, and their blends of soybean and sunflower biodiesel (5, 20 and 100% in volume). The results showed an increase of disks wear with reduction of sulfur content when lubricated with pure diesel. This fact was decreased when biodiesel was added to all concentrations.

Analysis of Lubricant Action of Biodiesel Using Response Surface Methodology

“…The response surface generated for percentage of film formation (Figure 05) for fuel and concentration showed that high percentage of film formation is reached for the concentration levels above of center and high point. These results are consistent with the literature [4,5,6,8]. The biodiesel lubricity is due to the presence of a polarityimparting heteroatom, the oxygen, as well the presence of a carbonyl moiety.…”

“…However, statistical errors observed in the model used were higher than expected (0.05 for 95% level of confidence). The trend of responses corresponds to that proposed by previous studies in this area [4][5][6]8]. It means that the friction coefficient decreases as the concentration of biodiesel increases.…”

“…Thus, the diesel engine with low sulfur content requires suitable additives to improve the lubricating properties. In their studies, Mello et al [4] evaluated the effect of the low sulfur diesel (LSD) and high sulfur diesel (HSD) on diesel lubricity. Also, they studied the Biodiesel addition in diesel.…”

Evaluation of Lubricating Properties of Diesel Based Fuels Micro Emulsified With Glycerin

“…These formulations presented higher lubricity, contributing to a lower abrasive wear. According to these results, the low values in the wear are because the three polar groups of the type OH present in glycerin give it a better adsorption on the surface, consequently increasing the efficiency in the metal coating and improves lubrication capacity, protecting the surfaces 17 . Additionally the minimized evaporation effect for these formulations also contribute to generate these smaller scars.…”

“…Mello et al 17 evaluated the tribological characteristics of 50, 500 and 1800 ppm sulfur diesel fuels and their mixtures with soybean biodiesel and sunflower biodiesel with mixtures of 5%, 20% and 100% by volume. The results showed that the wear and coefficient of friction (COF) increase with the reduction of the sulfur content in pure diesel.…”