MENESES, J. M.; http://lattes.cnpq.br/0574035618533787; MENESES, Janaina Moreira de.
Resumo:
Faced with a growing demand for energy in the world and the increase of air pollution caused
by the use of fóssil fuels, the search for renewable energy sources has grown considerably.
The processused in biodiesel plants use basic homogeneous catalysts, although they lead to
high yields, this requires highly refined oil sand purification steps of the final product which
is contribute to a high production cost. Starting from this premise, we seek to develop a lowcost
heterogeneous catalyst to simplify the production process, which could best able and
provides high conversions under mild reaction temperatures. Thus, this study aimed to
prepare metal catalysts supported on activated carbono and apply them in the production of
methyl and ethyl biodiesel using degummed and neutralized cottonseed oil, in batch reactor
with agitation, evaluating the conversion into esters. The catalysts were prepared by wet
impregnation at a mass concentration of 5%. They were characterized by techniques of DRX,
FRX, IFTR, MEV, Boehm tritation and textural analysis. Preliminary tests identified that the
molybdenum catalyst offered the best results in the simultaneous reaction of methyl and ethyl
ester/transesterification, with conversion of 43% and 40% respectively. Once selected the
catalyst, this was applied to a 23 factorial design to determine the effect of variables: reaction
temperature (80-160°C), molar ratio oil:alcohol (1:6 to 1:12) and catalyst concentration (1 to
3%); and the response variable was ester content. And it was found that the temperature
variable was the greatest influence and acts positively on the ester/transesterification
reactions, leading to 91% conversion in ester content. From analysis of response surfaces, it
was found that the optimal operating conditions leading to a higher conversion to esters are:
temperature 160°C oil molar ratio: 1:13 alcohol and catalyst concentration 3,2%. The results
of the recycle showed that reuse of the catalyst can be reused consecutively achieving good results, there was a decay of only 7% in the ester content to be reused in the 3rd cycle. The kinetic monitoring demonstrated that 5 hours of reaction with the best reaction conditions it is possible to achieve a 97.3% ester content.
