Avaliação do potencial do ácido tânico e do líquido extraído da castanha do caju (Anacardium occidentale L) como antioxidante para biodiesel

Abstract

Oxidative stability is one of the most important properties that attest to the quality of a biodiesel. This fact can affect the storage and their use as fuel and to prevent this oxidation, it is necessary the use of compounds that show efficacy against oxidative process into biodiesel. Thus, the present work had as general objective to evaluate the effect of Tannic Acid (TA) and the liquid extracted from the Cashew Nut (Anacardium occidentale L.) (LCC) as antioxidant for biodiesel, analyzing the General characteristics of oxidation. To this end, we used a methodology where the study of the stability of biodiesel was performed by means of Rancimat, Thermogravimetry, spectrophotometry and the analysis of acidity. By means of Rancimat analysis, it was found that all additives biodieseis showed an increase of PI (induction period), an increase of oxidative stability, progressively increasing the addition of antioxidant. The thermogravimetric maid evaluation showed that the LCC a higher initial temperature presented technical and minor final temperature of decomposition when compared with other antioxidants tested. The results of the tests of acidity and spectrophotometry in the kiln and prolonged storage, with all the antioxidants tested, showed no significant increase in oxidation due to the type of test used, which sought to reproduce the actual conditions of storage. It is worth noting that the results found in this research meet the quality parameters required by the regulator of biofuels, the ANP.