Recovery and characterization of oil from co-products of corn ethanol production.

摘要

Recovery and characterization of oil and other components in co-products of Corn ethanol production was carried out to find other ways to use the co-products, which are currently used as animal feed. Different extraction methods were adapted to extract oil from the co-products as well as to maximize the yield. Hexane was used to extract oil from DDG by continuous solvent extraction and after evaporation the oil obtained was analyzed for free fatty acids and refined with comparison to corn oil.;Thin stillage which was also a co-product was centrifuged (sample size-50g) under different conditions of temperature (0° C and 25° C) and pH (4, 5 and 8), three distinct layers were obtained, a top layer, a middle layer and a bottom layer. All the three layers obtained at different conditions were evaluated for weight, oil, protein, and solid distribution. Whole stillage was also centrifuged (sample size-50g) under different conditions of temperature (0° C, 25° C and 50° C), pH (2, 4, 5 and 8) and a sedimenting agent(CaCl2). The three layers obtained from different conditions were evaluated for weight, oil, protein, and solid distribution.;Weight distribution was determined by separating the three layers and calculating the percentage distribution of the three layers. Oil distribution was calculated by using liquid-liquid extraction and solid-liquid extraction (bottom layer) with the help of hexane from the three layers and percentage oil distribution of the three layers was calculated. Protein distribution in three layers was calculated using a protein analyzer and percent protein distribution was calculated. A solid distribution in the three layers was determined by drying the samples in oven and by calculating the percent solid distribution. All the distributions of the contents were statistically analyzed using SASRTM.;DDG Oil extracted from DDG using hexane was analyzed. Higher amounts of FFA were observed when compared with Corn oil. Refining losses were higher in DDG oil due to higher FFA content. In the treatment of thin stillage, the amount of oil in the top layer was found to be higher at lower temperature and pH 4 (20%). High protein distribution was observed in the sediment at lower temperatures (43.4%). At lower temperatures, oil in the top layer was easily and efficiently separated out which was not very efficient at higher temperatures. Whole stillage had the maximum oil distribution in the top layer at 0°C and pH 8 (13.2%). Higher amount of protein was yielded in the bottom layer at 50°C and pH 8 (90%). Addition of CaCl2 did not have any effect on amount of protein in the bottom layer.