Vinicius M. Mello

Determination of the content of fatty acid methyl esters (FAME) in biodiesel samples obtained by esterification using 1H‐NMR spectroscopy

Three different calibration curves based on 1H‐NMR spectroscopy (300 MHz) were used for quantifying the reaction yield during biodiesel synthesis by esterification of fatty acids mixtures and methanol. For this purpose, the integrated intensities of the hydrogens of the ester methoxy group (3.67 ppm) were correlated with the areas related to the various protons of the alkyl chain (olefinic hydrogens: 5.30–5.46 ppm; aliphatic: 2.67–2.78 ppm, 2.30 ppm, 1.96–2.12 ppm, 1.56–1.68 ppm, 1.22–1.42 ppm, 0.98 ppm, and 0.84–0.92 ppm). The first curve was obtained using the peaks relating the olefinic hydrogens, a second with the parafinic protons and the third curve using the integrated intensities of all the hydrogens. A total of 35 samples were examined: 25 samples to build the three different calibration curves and ten samples to serve as external validation samples. The results showed no statistical differences among the three methods, and all presented prediction errors less than 2.45% with a co‐efficient of variation (CV) of 4.66%. Copyright

Synthesis, characterization and use of nb2o5 based catalysts in producing biofuels by transesterification, esterification and pyrolysis.

Nb2O5/HX (X = HSO4-, H2PO4-, NO3-) compounds were obtained from the treatment of niobium acid (Nb2O5·xH2O) with sulfuric, phosphoric, and nitric acids as well as Nb2O5 and Nb2O5·xH2O have been investigated as catalysts for the transesterification, esterification and pyrolysis of vegetable oils. The compounds were characterized by thermal analysis (DTA-TGA), spectroscopy (DRX, FT-IR and FT-Raman), surface area (BET) and the acidity (Ho) determined by n-butylamine titration using the Hammet´s indicator method. It was observed that after the acid treatment both the surface area and the acidity decreased as compared to the starting Nb2O5·xH2O. The only exception was a higher acidity verified when nitric acid was used. Among the catalyst investigated, the Nb2O5/H3PO4 presented the highest activity in the alcoholysis of soybean oil with different mono-alcohols (methanol, ethanol, 2-propanol, n-butanol). All tested solids seemed to stabilize the carboxylic acids formed during the pyrolysis, yielding higher acid numbers for the obtained products. Finally, the use of Nb2O5/H3PO4 and Nb2O5/H2SO4 as catalysts for the esterification showed better activity than Nb2O5·xH2O and Nb2O5.

Turning used frying oil into a new raw material to printing inks

Used frying oil (UFO) obtained from industrial food preparation was evaluated as raw material to produce biobased resins suitable to be used as binder in printing inks (offset or typographic printers). The polymerization of UFO was compared with selected refined oils described in the literature to produce printing inks. After 3 h, the UFO-polymer viscosity was up to 80% higher than using refined soybean oil in similar conditions. This behavior is possibly associated to a smaller induction time when using UFO. The polymerization increased the acid value in all feedstock used because of the formation of carboxylic acids. Using metal complex of the type M(carboxylate)2 (M = Ni2+, Fe2+, Cu2+, Co2+ and Sn2+) as catalyst precursor for UFO polymerization, the viscosity increased up to 75% when compared with non-catalyzed reactions.

The Expressive Ink Formulations Through History

This manuscript describes the main technological developments and their impact on the preparations of paints. Initially, man used metal oxides and hydroxides to produce rock art, where colloquial scenes, such as hunting, fishing, fruits recollection, fighting and sex, were described. When civilization started up techniques were developed for the preparation of Watercolor, Gouache, China ink and Tempera, that together with new synthetic pigments have been the raw materials for all artistic production for millennia. Approximately in the XV century the use of oils to prepare paints was the basis for renaissance art production. Finally, the petrochemical revolution in the XX century changed the artistic market, with special contribution of the acrylic inks, which are now the mostly used by artists.