Authors:F. Lanças, M. Barbirato, and N. Antoniosi filho
Three nitrogenated fungicides (Bayfidan, Bayleton and Baycor) were irradiated with -rays from a60Co source with the products being analyzed by high resolution gas chromatography (HRGC). Within the dose range studied (5 to 640 kGy), all three compounds were found to be stable.
Authors:R. Medeiros, Maria Leles, F. da Costa Dias, Rosana Kunert, and N. Antoniosi Filho
Petroleum samples were analyzed by TG between 25–600°C. Mass loss was observed up to 500°C. The volatile fraction of petroleum
samples in the range of 25–150°C were recovered by bubbling the outgoing gaseous products of the TG experiments in dichloromethane.
Each volatile fraction obtained was analyzed by HRGC-MS for identification and quantification of the major components. Following
this procedure the classification of the petroleum samples were done according to the obtained mass losses between 25–150°C
(which varied from 1.76 to 21.89%) and according to their normal paraffin, aromatic and naphthene contents.
Authors:C. Garcia, P. Franco, T. Zuppa, N. Antoniosi Filho, and M. Leles
technique is useful to determine the thermal stability of vegetable oils.
In this paper some vegetable oils obtained from brazilian Cerrado native plants
were studied based on their high oleic acid content. Amburana, baru and pequi
pulp oils presented higher yield of extraction compared to soybean oil. The
thermal stability of oils in nitrogen was very close hence their fatty acid
composition was very similar. Amburana and baru oils have major amount of
unsaturated fatty acids, especially linoleic acid and pequi pulp oil has the
highest short chain fatty acid content which can explain its lowest thermal
stability in synthetic air.
Authors:A. Vasconcelos, M. Dantas, M. Filho, R. Rosenhaim, E. Cavalcanti, N. Antoniosi Filho, F. Sinfrônio, I. Santos, and A. Souza
The influence of drying processes in the biodiesel oxidation was investigated by means of the oxidative induction time obtained
from differential scanning calorimetry data. For this purpose, corn biodiesel was dried by different methods including: chemical
(anhydrous sodium sulfate) and thermal (induction heating, heating under vacuum and with microwave irradiation). The drying
efficiency was evaluated by monitoring IR absorption in the 3,500–3,200 cm−1 range and by the AOCS Bc 2-49 method. In general, the oxidative induction times increased inversely to the heating degree,
except that of microwave irradiation, which was selective to water evaporation and caused low impact over the unsaturation
of biodiesel. The DSC technique was shown to be a powerful tool to evaluate with high level of differentiation the influence
of the drying process on the oxidative stability of biodiesel.
Authors:N. Santos, J. Santos, F. Sinfrônio, T. Bicudo, I. Santos, N. Antoniosi Filho, V. Fernandes, and A. Souza
The babassu (Orbignya Phalerata Mart.) biodiesel has lauric esters as main constituents, resulting in high oxidative stability and low cloud and freezing
points. In order to reduce these side effects, the saturated ethyl esters content was reduced by means of winterization process.
The TMDSC and PDSC techniques were used to verify the thermal and oxidative stabilities of the ethyl babassu biodiesel. During
the heating stage, the winterized solid phase of ethyl esters presented an endothermic transition associated to the solidification
process. This behavior was not observed for the liquid winterized FAEE, confirming the efficiency of the winterization process.
Authors:L. Freire, T. Bicudo, R. Rosenhaim, F. Sinfrônio, J. Botelho, J. Carvalho Filho, I. Santos, V. Fernandes, N. Antoniosi Filho, and A. Souza
Biodiesel is susceptible to autoxidation if exposed to air, light and temperature, during its storage. Physic nut (Jatropha curcas L.) seeds show potential application for biodiesel production since its oil yields high quality biodiesel. This work aims
to evaluate the thermal behavior of the physic nut oil and biodiesel, from several Brazilian crops, by means of thermoanalytical
techniques. Thermogravimetry (TG) and pressurized-differential scanning calorimetry (PDSC) were used in order to determine
the applicability of physic nut biodiesel as fuel. Results suggest that physic nut biodiesel is a practical alternative as
renewable and biodegradable fuel able to be used in diesel motors.