Figure legends
Fig. 1 Scheme of the Magnesol® purification process
Fig. 2 Magnesol® purification process
Fig. 3 Acid value of biodiesel: unpurified biodiesel, purified with virgin Magnesol® (purified I) and purified with recovered Magnesol® (purified II). B-1 and B-2 represents virgin oil and frying oil, respectively
Fig. 4 Quantity of glycerols in unpurified and purified biodiesel: virgin oil (A1) and subsequently purified with virgin Magnesol® (A1.1) and recovered Magnesol® (A1.2); frying oil (A2) and subsequently purified with virgin Magnesol® (A2.1) and recovered Magnesol® (A2.2)
Fig. 5 Micrographs, magnification of 600x: (a) Virgin Magnesol®, (b) Recovered Magnesol®used in the purification of biodiesel from frying oil and (c) Recovered Magnesol® used in the purification of biodiesel from virgin oil. The images in (d), (e) and (f) show micrographs with magnification of 1000x for the Magnesol® shown in (a), (b) and (c), respectively
Fig. 6 FTIR Spectra of virgin and recovered Magnesol®. Virgin Magnesol (VM); Magnesol® used in the biodiesel purification: virgin soybean oil (M-1) and frying soybean oils (M-2); recovered Magnesol®: virgin soybean oil (RM-1) and frying oil (RM-2)
Fig. 7 Thermal gravimetric analysis (TGA) and differential thermal gravimetric analysis DTGA graphs of virgin Magnesol® (VM), recovered Magnesol®used in the purification of biodiesel from virgin soybean oil (RM-1) and recovered Magnesol® from the purification of biodiesel from frying oil (RM-2)