Alternative Multifunctional Additives for Biodiesel Stabilization: Perspectives for More Efficiency and More Cost-Effectiveness

An Analytical Evaluation of the Synergistic Effect on Biodiesel Oxidation Stability Promoted by Binary and Ternary Blends Containing Multifunctional Additives

“…The influence of individual additives on biodiesel stability, according Rancimat method, is shown in Table 4. The results show that pure biodiesel (P) had an induction period of 3.76 ± 0.25 h, in accordance with previous results reported in the literature [10, 12, 18]. Differently, for the sample P-A1, there is only copper addition in its composition, and the IP drops to 0.20 ± 0.05 h. These results demonstrated that the addition of Cu(II) induced the reduction of biodiesel stability due to the high catalytic activity associated with metal [12].…”

“…Among all the advantages associated with biodiesel, low oxidative stability has been one of the main drawbacks to its consolidation in the world energy matrix and consequently one of the most important challenges for the development of this area [10]. Biodiesel oxidation has its origins in the unsaturated fatty acids carbon chains which are easily oxidized, forming primary degraded compounds (e.g., peroxides and hydroperoxides) and then secondary compounds (such as ketones, aldehydes, and carboxylic acids) [11].…”

“…Synthetic antioxidants are effective and widely applied to improve the oxidation stability of biodiesel [17]. However, depending on the biodiesel composition, especially the number of unsaturations in carbon chains, a high amount of these additives is required to obtain the mandatory specifications requested by the standards agencies, increasing the production costs [10]. In this sense, an efficient antioxidant additive must improve the shelf life of biodiesel without change any other properties of this fuel.…”

“…Aiming to improve the antioxidative action of additives, synergistic combinations of different antioxidants with other compounds can be applied to biodiesel stabilization and reduce the amount of used additives. Our research group recently reported that the use of anthraquinone dyes in combination with synthetic antioxidants can significantly improve the biodiesel oxidative stability [9, 10, 12, 20, 21]. The results revealed the existence of a positive synergism, in which the combinations were more efficient when compared to the individual additives, providing greater stability to the biodiesel even in presence of prooxidative metals [9, 10, 12, 20, 21].…”

“…Our research group recently reported that the use of anthraquinone dyes in combination with synthetic antioxidants can significantly improve the biodiesel oxidative stability [9, 10, 12, 20, 21]. The results revealed the existence of a positive synergism, in which the combinations were more efficient when compared to the individual additives, providing greater stability to the biodiesel even in presence of prooxidative metals [9, 10, 12, 20, 21]. In the present study, we evaluate the antioxidant potential of a novel additive, named maleimide p -CH 3 , and its combination with a traditional synthetic antioxidant (e.g., propyl gallate, PG), as well as the alternative additives (e.g., alizarin, ALZ, and citric acid, CA) in order to have a mixture of multifunctional additives.…”