Physical refining of edible oils using nitrogen as stripping gas. Process optimization

Abstract

The use of nitrogen as a stripping gas in physical refining of edible oils represents a technological improvement with potential advantages such as the possibilities of recovering high quality deodorized distillates and eliminating pollution. The objectives of the present paper are to study, evaluate and optimize, as far as possible, independent variables involved in the process (nitrogen flow, operating temperature and the height of the oil layer inside the deodorizer) in reference to the quality of the obtained oils as well as the manufacturing requirements. All the experiments were carried out with sunflower oil in a discontinuous deodorizer with a 200 Kg capacity. A 4x4 Latin square experimental design was used, consisting of three factors, each of which had four different levels. The results led to the establishment of charts that allow to determine the most suitable conditions in which to carry out the processing in accord with the desired quality of the finished oil and the functional objectives of the factory. These charts are presented in the paper. The results were checked by another set of experiments.