Perdas de solvente hexano em um processo de extração de óleo de soja: análise e prospecção de novas tecnologias

Abstract

Soybean oil extraction with hexane solvent is widely used in the industry, but solvent loss represents a major safety, economic and environmental challenge. To address this problem, this study was carried out in a soybean oil extraction unit and aimed to evaluate the solvent loss in the process, its factors and causes, and to propose specific actions and new technologies that could be used to minimize the consumption of this input, mitigate the risks inherent to the product and reduce process costs. To this end, the work was structured in three stages: (1) Quantification of the points of solvent loss in the process; (2) Identification of the factors and causes involved in the loss at each point and (3) Prospection of new technologies that influence the solvent recovery process. The main points of hexane loss identified in the oil extraction were carryover with toasted bran, degummed oil, flue gases and water from the boiling tank. In addition, losses at scattered points in the extraction process were considered as process leaks, which can occur for various reasons, such as leaks, maintenance, operational problems, and others. Each loss point was monitored at a specific measurement point using a multigas detector. Of these points, those with the highest average solvent concentration in the process studied were the toasted bran and the extraction chimney. In the end, it was concluded that a more effective solution would initially involve reassessing and modifying the DTSR and the extraction gas recovery system. The capacity of the cooling tower and condenser systems, in addition to other precautions, also need to be considered. In addition to improvements that can be made to the existing industrial plant, it was also found that the implementation of modern technologies presents itself as a viable solution for significant reductions in solvent losses.