Características físico-químicas de blendas de biodiesel de óleos vegetais durante o armazenamento

Abstract

Biodiesel is a renewable fuel of plant or animal origin, composed of a mixture of alkyl esters of long-chain carboxylic acids. Some oilseeds are being used as raw material for the production of this biofuel, such as soybeans, cotton and corn. In this work, the objective was to carry out an evaluation of the physical-chemical characteristics of biodiesel blends from rice and cotton oils under different storage conditions. Biodiesels were synthesized through the transesterification reaction, using methanol as a transesterifying agent and sodium methylate as a catalyst. The blend was prepared with a proportion of 50% (v/v) and divided into two samples, one being stored in a transparent glass bottle in contact with light, and the other in an amber glass bottle protected from light. During the 6-month period, the following characteristics were monitored: kinematic viscosity, acidity index, density, iodine index and peroxide index. Analyzes were performed every 30 days. The results obtained showed that the samples suffered oxidation throughout the storage period, since the analyzed parameters underwent constant variations. The parameters kinematic viscosity, density and acidity index are established by ANP 920/2023. Of these, only the density of sample B50-FT remained in compliance with regulatory standards after the storage period, and in relation to sample B50- FA, the parameters density and acidity index remained in compliance until the end of the monitoring period. It must be considered that no antioxidant additive was used in this work.