4. Conclusion
Through the analysis of total carbon, it can be observed that the
methodology used in the purification of Magnesol® is
satisfactory, as approximately 3.90% carbon was found after the washing
process with THF. This was proven through infrared analyses which showed
the absence of signals around 2900 and 2700 cm-1 in
the purified Magnesol® as well as a decrease in the
signal at 1000 cm-1, resembling virgin
Magnesol®.
After the Magnesol® was purified with THF (r.t., 30:1
solv./Magnesol®; 3 stages, duration of 10 min. for
each wash), we observed different behaviors depending on whether it was
used with virgin oil or frying oil. For the Magnesol®used in the purification of biodiesel from the virgin soybean oil, we
found it can be used at most two times without losing its efficiency,
whereas the Magnesol® used in the purification of
biodiesel from soybean oil used in frying can be used at least 2 times,
as no loss of efficiency was observed. These results were verified in
the glycerol analyses presented in this study.
After the acidity, glycerol, flash point and density tests, it was found
that biodiesel after being purified with Magnesol® is
in good condition to be used in industry with less glycerol, the main
impurity.