Biodiesel is an alternative fuel obtained from different biomass sources and processes. Nowadays, this biofuel has gained importance due to environmental concerns and rising energy demand. In the biodiesel production chain, stability is a critical issue, as it is linked to the maintenance of its original properties. This work performed a study evaluating the influence of storage conditions on the quality aspects of biodiesel. Thus, different samples of biodiesel obtained from soybean and frying oils were produced and placed in containers made by plastic, glass and tin, and stored in presence or absence of an oxidative atmosphere, moisture and light. These samples were analyzed to evaluate the ester content, acidity, iodine value, kinematic viscosity and oxidative stability. The characterization with GC-MS and GC/FID were done aiming to determine the chemical composition. Blends with frying biodiesel into soybean biodiesel have also been produced in concentrations ranging from 1%, 5% and 10% (m/m) in order to evaluate the mixing effect. In the initial storage time, all tested parameters were in accordance to the legislation. Distinct behaviors were identified for each sample according to the container type, being the glass the most effective of them in maintenance of biodiesel characteristics.

In this work, cracking experiments were performed to carry out the thermal conversion of the mixture of used frying oil and textile stamping sludge in continuous reactor. The textile stamping sludge was used to catalyze the reaction of thermal cracking. The physical and chemical properties of the oil produced were analyzed. Among the results of this analysis the level of acidity in the range of 12 mg KOH/g stands out. Low levels of acidity as this particular mean better quality oil. In this regard it is important that further researches on processes of conversion of residual oil occur.

Os resíduos gordurosos provenientes de caixas de gordura foram avaliados como substrato para obtenção de biodiesel, em escala laboratorial. Os resíduos foram desemulsificados, purificados e submetidos à reação química de transesterificação com catálise alcalina e esterificação com catálise ácida para a obtenção de ésteres etílicos. O produto obtido foi purificado por adsorção em coluna de sílica, e caracterizado por cromatografia gasosa com sistema de detecção de massa. Os percentuais de conversão da gordura em ésteres etílicos foram calculados com o fechamento dos balanços de massa do processo. Os produtos obtidos foram purificados com o uso de processos secundários de forma a viabilizar sua utilização como bicombustível e insumo para diversos processos industriais, respectivamente.

Waste fatty acid, from fatty boxes was evaluated as feedstock to obtain biodiesel in a laboratory scale. The residues were desemulsified, purified and used to obtain ethyl esters, through the transesterification with alkaline catalysis and esterification with acid catalysis reactions. The product was purified by adsorption in column of silica, and characterized by GLC with mass detector. Using this methodology the fatty residues was converted in the ethyl esters showed the scientific e technical validation of this propose. The conversion of fatty acids in ethylic esters was calculated by mass balances processes same for the highs degradation of the residue evaluates. To purify the biodiesel and glycerol obtained was necessary secondary processes to increase the qualities of this full and to use the glycerin in many industrial processes.