produção de biodiesel a partir de óleo residual reciclado e ...

ABSTRACT
This study analyzes the technical production of biodiesel from waste oil recycling,
aimed at diversifying the Brazilian energy matrix and minimizing the environmental impacts
of inadequate disposal of waste oils. Before the production of biodiesel it is necessary to
perform a previous treatment of this oil, which involves processes of filtration, drying and
determination of acidity, followed by neutralization, because according to the percentage of
free fatty acids present in the raw material is that the methods for obtaining the esters are
defined. Firstly, laboratory tests were performed on a small scale biodiesel production using
raw materials like soybean oil and recycle waste soybean oil for comparison, having been
used sodium hydroxide as catalyst and tested methyl and ethyl routes, being no obtained
satisfactory results in this last case. Then, the production was expanded to a semi-pilot scale,
using a reactor that can produces between 75 and 80 liters of biodiesel per batch, being in
which case only used recycle waste oil and the transesterification process using methanol
route, with sodium hydroxide as catalyst. After that, a basic characterization of biodiesel had
been done, using equipment available, and were conducted comparative tests with other types
of biodiesel (commercial, vegetable and animal) and fractions of blends (B25, B50, B75 and
B100), with commercial biodiesel like base of comparison (B5). Finally, tests were performed
with these fuels in a 6 kVA diesel generator set, varying a resistive load from 0 to 3 kW and
determining the specific consumption and temperature of the exhaust gases. Analyzing the
results, it was verified that the physical and chemical properties measured are within
acceptable limits, with density between 0,871 and 0,910 g/ml, viscosity between 3,9 and
6,1 cSt and flash point between 51 and 183°C, except that the pH was a out of desirable
range, being few acid. It was noteworthy that the values of these properties are directly
proportional to the amount of B100 added to B5 for the constitution of mixtures and, for the
same mixing ratio, viscosity of biodiesel by waste was greater than oil by animal source,
which in turn it has more viscosity than biodiesel by vegetable oil source. As expected, tests
in the generator set showed that both the specific fuel consumption as the temperature of
exhaust gases increased with increasing resistive load. However, there were no significant
variations of these parameters for the same load, regardless of fuel used. Under the economic
and ecological aspects, it is believed that the recycled residual oil becomes promising source
for electricity generation.
Keywords: Biodiesel. Transesterification. Waste cooking oil. Methanol. Ethanol.
Acid catalyst. Basic catalyst. Motogenerator.