Biodiesel is an eco-friendly type of fuel which is produced from plants (rapeseed, soybeans) or animal fats via chemical reactions. When this fuel is obtained, the fuel mixture contains glycerol, which must be removed to prevent engine clogging. Biodiesel also needs to be purified to ensure that its qualities meet international standards.
Today, the primary methods of fuel purification include electrolysis, crystallization and filtration columns. During electrolysis, glycerol ions are removed from the liquid through ion-exchange membranes under the influence of an electric field. Crystallization makes it possible to isolate glycerin with a solvent, and in the case of filtration, principal fuel is separated from water using a special filter.
The SPbU scientists have developed an alternative to these expensive methods using deep eutectic solvents – a mixture of components the temperature of which is significantly lower than the melting point of the original substances. To obtain such solvents, the authors used choline chloride (a white crystalline powder with a distinctive amine smell) and urea, which is used to produce mineral fertilizers.
“These substances are characterized by low toxicity, non-flammability, low volatility and rapid biodegradability. Moreover, they can be easily reused, which makes them highly sought after in various industries from agriculture to energy,” Maria Toikka, candidate of chemical sciences, is quoted as saying by SPbU.
During the production of deep eutectic solvents, the starting materials are mixed and heated to obtain a product the purity of which does not deteriorate with further use. Thanks to these properties, the authors have created a solvent that can extract glycerol from biodiesel samples containing fatty acid methyl esters.
The commercialization of the study results could reduce the cost of producing eco-friendly fuel.
