Water-free process for eco-friendly purification of biodiesel obtained using a heterogeneous Ca-based catalyst

GABRIEL ORLANDO FERRERO; MANUEL FONSECA ALMEIDA; MARIA DA CONCEIÇÃO MACHADO ALVIM-FERRAZ; JOANA MAIA DIAS

FUEL PROCESSING TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Filadelfia; Año: 2014 vol. 121 p. 114 - 118

0378-3820

Conventional biodiesel purification technologies imply high energy and water consumptions. In the present work, biodiesel prepared using a very active calcium glyceroxide catalyst was purified using water-free processes. The study focused on soaps removal, the main product impurity. The best results were obtained when crude biodiesel (methyl ester content of 90.2-91.2 wt.% and calcium content of 372 ? 393 ppm) was pre-treated with Na2CO3 and after purified with an ion-exchange resin (6 wt.%) or a ceramic membrane (0.1 μm). The treatment was effective using biodiesel produced from both soybean oil and waste frying oil and the results agreed with the ones obtained using the conventional water washing process. The effectiveness of the treatment could be explained by calcium elimination through precipitation as CaCO3 and sodium soaps removal by absorption into the resin or filtration by the ceramic membrane, according to a micelle formation mechanism. The studied process presents high potential towards the removal of calcium soaps from biodiesel.