Evaluating corrosion effect of biodiesel produced from neem oil on automotive materials

Abstract

In this study, biodiesel was produced from neem oil feedstock by using a single-step direct transesterification process method. The single-step direct transesterification process method uses acid-base catalysts simultaneously. The fuel characteristics of biodiesel made from neem oil and different biodiesel-diesel blends were investigated and compared. In terms of kinematic viscosity, calorific value, and density, biodiesel made from neem oil performed better. Transesterification, particularly alkali-catalyzed transesterification, is the most prevalent method for producing biodiesel. The alkali catalyst reacts with the free fatty acids to create soaps when the raw materials (oils or fats) have a high proportion of free fatty acids or water. Water can hydrolyze fats into diglycerides, resulting in the formation of additional free fatty acids. Many of the preceding reactions are unfavorable and diminish the biodiesel product’s production. The acid ingredients must be pretreated to prevent the saponification process in this case. Alcohol percentage, reaction duration, reaction temperature, and catalyst amount are the primary factors impacting biodiesel production. This research shows that neem oil has a satisfactory consistency for valorization in biodiesel production based on its physicochemical properties. After biofuel production, the current study investigates the corrosion effect of biodiesel on pure copper by means of immersion testing. The corrosion rate of neem biodiesel and diesel was both observed in copper. It is noted that the corrosion rate increases when the concentration of biodiesel increases in conventional diesel. The corrosion rate is 8.108 μm/year in the case of 10% biodiesel and 90% pure diesel, 9.9103 μm/year in the case of 20% biodiesel and 80% pure diesel, 15.315 μm/year in the case of 30% biodiesel and 70% pure diesel, and 38.740 μm/year in the case of 100% biodiesel.