This work examines pressurized accelerated oxidation by a RapidOxy tester as
an alternative method for determination of biodiesel oxidation stability.
Sunflower oil-based biodiesel was synthesized and treated with antioxidants:
tert-butylhydroquinone (TBHQ) - a synthetic antioxidant known for its
powerful protective effect, and a mixture of bio-based antioxidant compounds
extracted from vinery waste, VWEeth. The antioxidant potency of TBHQ was
evaluated at varying temperatures (110 - 140 ?C) and concentrations (250 -
2,000 mg dm-3) by the RapidOxy method; assessment of selected results was
performed by comparison with relevant data obtained by the standard Rancimat
method. VWEeth was added in two high dosages to biodiesel (87,500 and
150,000 mg dm-3) and analyzed at 140 ?C by the RapidOxy method. Both
antioxidants at all applied dosages showed beneficial effects on improving
the oxidative stability of biodiesel, but not all of the achieved
improvements reached the stability minimum identified by the EN14214
standard. The lowest addition of TBHQ seemed to have a similar effect as the
tested dosages of VWEeth but these additions did not increase the induction
period above the limit of 8 h; two-fold higher quantity of TBHQ was
successful in this respect, increasing the initial oxidation stability by a
factor of about 2, which was determined by both methods. The RapidOxy method
proved to be a very fast method suitable for testing a large number of
samples, which is particularly important for efficient testing of different
types and doses of antioxidants.