Evaluation of biodiesel dehumidification with inorganic drying salts

Low value-added oil extracted from pequi (Caryocar brasiliense) was previously treated by the degumming process to make biodiesel more competitive against fossil diesel. The physical-chemical characterization of this raw material revealed a high level of free fatty acids and humidity. These parameters are the main responsible for more than 85% of the biodiesel processing costs.The degummed oil was submitted to transesterification process by basic homogeneous methyl route to obtain methyl esters. The biodiesel obtained was dehumidified using inorganic drying salts. The results obtained allowed us to infer that the use of drying salts was not an appropriate procedure for removing the water content of methyl biodiesel produced from pequi oil treated by degumming, since the addition of these salts did not contribute to the dehumidification stage of the biodiesel samples studied reached the specification required by the ANP through Resolution 045 of 25/08/2014, whose maximum limit is 250 ppm/kg of the sample. (author)