Alternative Process Design for Pesticide Reduction in an Edible Oil Industry Byproduct (Oil Deodorization Distillate)

Abstract

Current food trends emphasize natural, nutraceutical-rich foods that are free of chemical contaminants. The goal of this study is to reduce the presence of pesticides in an oil deodorization distillate, an economical raw material rich in natural antioxidants, such as tocopherols and phytosterols. However, as a byproduct of the edible oil refining industry, it contains pesticides, which are undesirable in the final product. In this study, two common technologies employed in the edible oil industry, namely,steam-distillation and steam stripping, are analyzed for their effectiveness in separating endosulfal (pesticide) from antioxidants. An industry standard oil deodorization distillate stream with a flow rate of 40 kg/h containing 39.6 wt % of tocopherols, 52.6 wt % of free fatty acids, and 7.8 wt % of pesticide is considered, and the process variables such as temperature, steam flow, and number of separation stages are examined. These results show that both technologies reach the final product concentration to the maximum residue limits for the final product. The stripping technology has better economic and productivity performance. With this technology, the net annual income (NAI) reached was 2.5 million US$/y, while the optimum process variables were a temperature of 190 °C for feed products, 4.9 kg/h of feed steam, and 8 stages of separations. The performance was about 30% larger than that for the deodorizer. This study is highly attractive to edible oil industries looking to add value to their byproducts with minimal inversion cost. Otherwise, byproducts would have to be treated as high organic load and oxygen-demanding wastes.