Aproveitamento do óleo de fritura residual para produção de Biodiesel em Manaus

Abstract

The frying process is a rapid procedure and appreciated by the population, in order to acquire the sensory enjoyable characteristics food. There are numerous substances that alter the oil and fried foods obtained by hydrolytic reactions, oxidative and thermoxidative. The intake of these substances are harmful to health and disposal in local inappropriate, such as, sinks / drains, creeks, drainage can aggravate environmental problems, as well as promoting the pollution of rivers, leading to increased cost of water treatment and sewage and the proliferation of insects. This work was conducted to assess the level of degradation of waste frying oils (OFR) and their use as feedstock for biodiesel production, providing a knowledge/technology field of transformation of residual oil for frying in our region and therefore add economic value to this waste and minimize environmental problems caused by their disposal. Different samples of frying oil waste restaurant, residence and pastry were collected and characterized by analytical methods according to Instituto Adolfo Lutz, the results of free fatty acids was below 1%, the average acid value of 1.25 mg KOH / g oil, peroxide index of less than 10 meq O2/kg oil, saponification index ranged from 110.13 to 228.6 mg KOH / g oil and iodine in the range 85.96 to 106.17 g I2.100g-1. The fatty acid composition of these oils was similar to that of refined soybean oil, with a predominance of palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2), representing over 80% of the composition these oils. The viscosity averaged 43.65 mm2.s-1 and the average density was 0.9210 g.cm-3, values similar to soybean oil. The pastry samples had values above these parameters, resulting from the polymerization of the oil. Samples of frying of residence in relation to restaurant and pastry showed greater resistance to oxidation in the Rancimat test. The transesterification reactions were carried out via basic catalysis in reflux system and PARR reactor (model 5500), the optimized conditions, molar ratio of 1:6 (oil: methanol), 1% NaOH, 60 minutes reaction time and temperature of 65oC and 70oC. Biodiesel yields were obtained on average 90% and 87% respectively. Samples of biodiesel OFR were characterized by infrared spectroscopy, with characteristic spectrum of methyl esters. The biodiesel the (OFR) had lower oxidative stability to values recommended (6 h) due to degradation processes arising in the process of frying. The results of TG / DTG in an inert atmosphere, it was possible to analyze these volatility and thermal stability of biodiesel. The parameters determined for biodiesel OFR presented in accordance with the resolution of the ANP, namely, acid value, iodine value, viscosity and density. It was found that in Manaus-AM there is no registration about the production of biodiesel in industrial scale, justified by the isolation of the region, which entails in high cost of inputs for the biodiesel industry. This study indicated that Manaus has a potential supply of 296,100 liters per month of residual oil in the home, and timely deployment of a plant of 10,659 L / day of biodiesel. The costs of production and investment were also analyzed.