Uso da energia solar nos processos de lixiviação e destilação aplicados à produção sustentável de óleos vegetais

Abstract

The requirement for cleaner processes in economic and environmental aspects are challenges in the search for methodologies that achieve sustainability in the production of the most diverse genres, encompassing concepts ranging from waste minimization to substitution of energy matrices. In this same scenario, the demand for vegetable oils has intensified due to the growth of the oleochemical market in the biofuel, food, pharmaceutical and cosmetic segments. In the various nuances of sustainability, solar energy has stood out because it represents a nonpolluting and virtually inexhaustible source of the Earth with great potential of use. The main objective of this work was to study the use of solar energy in the leaching and distillation processes associated with obtaining peanut, coconut and baru oils. Upon extraction, the solvent is heated and percolates the particles of the material contained within a fixed bed. Two models of solar concentrators for the heating of the hydrous ethanol fuel solvent were used, one of parabolic-cylindrical shape and the other of twelve-sided biangular geometry. For the tests, the solvent feed rates were varied at 15, 25 and 35 mL/min, with 25 mL/min that presented better hydrodynamics at all extractions. The biangular prototype achieved a 15.34% greater efficiency than the first one in the extraction of the peanut oil, when compared the yield with the Soxhlet. For the extraction with the coconut and the baru two different granulometries were used in each one and the biangular concentrator reached efficiency of 70.88% and 89.24%, respectively, for the smaller granulometry evaluated. Solar distillation was used to recover the solvent resulting from miscella. The batch tests revealed to be 0.16 cm the ideal height for better evaporation rate. This value allowed the design of a continuous feed model so that the distiller always operated near the calculated height range. In the batch and continuous processes, distillation reached 84.2% and 75.58%, respectively, in the distillate collection and, in contrast, 26.86% and 44.22% of thermal efficiency. INMET data were obtained to analyze the influence of meteorological conditions.