Marcio de Figueiredo Portilho

Enzymatic Biodiesel Synthesis Using a Byproduct Obtained from Palm Oil Refining

An alternative route to produce biodiesel is based on esterification of free fatty acids present in byproducts obtained from vegetable oil refining, such as palm oil fatty acid distillate (PFAD). PFAD is a byproduct of the production of edible palm oil, which contains 96 wt.% of free fatty acids. The purpose of this work was to study biodiesel synthesis via esterification of PFAD with methanol and ethanol, catalyzed by commercial immobilized lipases (Novozym 435, Lipozyme RM-IM, and Lipozyme TL-IM), in a solvent-free system. The effects of reaction parameters such as type of lipase, enzyme amount, type of alcohol, alcohol amount, and enzyme reuse were studied. Fatty acid conversion of 93% was obtained after 2.5 h of esterification reaction between PFAD and ethanol using 1.0 wt.% of Novozym 435 at 60°C.

Modified Niobium Oxyhydroxide Catalyst: An Acetalization Reaction to Produce Bio-additives for Sustainable Use of Waste Glycerol

We report the synthesis and characterization of new niobium oxyhydroxide catalysts from ammonium niobium oxalate (NH4[NbO(C2O4)2(H2O)](H2O)n) or niobium chloride (NbCl5) precursors. The materials have been modified by incorporating a surfactant, specifically cetyltrimethylammonium bromide, on the catalyst surface to impart partial hydrophobicity to the catalyst. The change in the precursor during the synthesis changes properties associated with the morphology, texture and number of acid sites. These properties provide increased contact at the interface between the hydrophilic and hydrophobic regions to improve the catalytic properties, particularly in biphasic reactions. Acetalization reactions were tested using three different glycerols: commercial glycerol p.a., a crude residual originating from biodiesel production and the same material after desalination. The results show 65 and 60 % conversion for the acetalization under mild reactions conditions.

Influence of the Incorporation of Transition Metals on the Basicity of Mg,Al-Mixed Oxides and on Their Catalytic Properties for Transesterification of Vegetable Oils

The transesterification of vegetable oils produces fatty acid methyl esters (biodiesel). Biodiesel is a nonpolluting alternative fuel produced from renewable resources whose chemical and physical properties closely resemble those of the petroleum diesel fuel and does not contribute to the greenhouse effect. The use of solid catalysts makes biodiesel production processes environmentally friendly. In this work, Mg,Al-mixed oxides derived from Mg,Al-hydrotalcite-like compound with an M3

SnSO4as catalyst for simultaneous transesterification and esterification of acid soybean oil.

Biodiesel is an alternative biodegradable and non-toxic biofuel produced from renewable resources. Industrially, it is produced by catalytic transesterification of refined vegetable oil with methanol or ethanol. Biodiesel production costs can be reduced by using non-refined feedstocks whose market prices are lower than those of refined vegetable oils. This work studied the use of tin(II) sulfate (SnSO4), as catalyst for the simultaneous transesterification and esterification of model acid oil containing high levels of free fatty acids. The influence of experimental parameters, catalyst leaching as well as its reusability was investigated. For a model feedstock containing 70 wt. % of free fatty acids (oleic acid), the highest biodiesel yield (92%) was obtained at 100 oC, under autogenous pressure, using 5 wt. % of SnSO4 in excess of ethanol after 3 h of reaction. The catalyst was reused ten times without significant decrease in biodiesel yield.