Novos catalisadores à base de argilas para a produção do biodiesel.

Abstract

In the last decades a substantial amount of research has been undertaken to find new sources of renewable and sustainable energy to replace Diesel. A promising alternative energy source is biodiesel, which is a renewable fuel produced from vegetable oils and animal fats or even from recycled fat from the food industry. Heterogeneous catalysts can improve the synthesis methods eliminating additional costs associated with the homogeneous catalysts and minimizing the production of pollutants. Activated clays have attracted attention as catalysts for a variety of acid reactions. The physical and chemical behavior of clay minerals has been studied because of their property as adsorbent and / or catalysts. Therefore the need to develop studies on the use of clays as a catalyst in the production of biodiesel, making it, therefore, necessary to know the stability and properties of biodiesel produced by these catalysts. To evaluate the efficiency of clays as catalysts in the transesterification process of this fuel, 27 types of clay supplied by the company BENTONISA- Bentonite Nordeste SA, were studied in this work. The biodiesel was produced on the ethyl and methyl route, using soybean oil as raw material. The initial preselection for the clays was carried out on moisture and pH analysis, whereby 15 samples were selected. These were submitted to the testing systems in the S1 and S2, using the techniques of oil color (visual aspect) and viscosity. The two best clay catalysts (A23 and A24) were chosen to be tested in the standard system for production of biodiesel called S3. The catalysts A23 and A24 were characterized by: FRX; XRD; IR, SEM, EDS and BET. The soybean oil and biodiesel were characterized by the following techniques: chemical composition, moisture, acidity, density 20ºC, viscosity 40ºC, total glycerol, ester content, alcohol content and gas chromatography. The results showed that it is possible to get biodiesel from clay catalysts.