Biodiesel purification in microextractors: Choline chloride based deep eutectic solvents vs water

摘要

Nowadays, the production of biodiesel by transesterification is a common process. On the other hand, once the biodiesel is produced, the purification of crude biodiesel to the extent that satisfies international standard norms still presents a significant challenge. One of the biggest challenges is the removal of glycerol. In this paper, the total of seven different deep eutectic solvents (DESs) based on a mixture of choline chloride and ethylene glycol or a mixture of choline chloride and glycerol were prepared and applied for biodiesel purification, using three microextractors of different sizes. The obtained results were compared with the results of biodiesel purification by wet washing in the same microextractor type. For the residence time of only 13.61 s, by using a ChCl:Gly(1:2.5) DES, glycerol was almost completely removed from the biodiesel. So, the obtained result clearly justifies the application of DESs in microextractors for glycerol removal during biodiesel purification.