RESUMO
Two bentonites from Paraíba (Northeastern Brazil) were impregnated with heteropoly phosphomolybdic H3PMo12O40 (HPMo). The materials produced were characterized by various techniques such as N2 adsorption-desorption (specific surface area, SSA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA/DTG), Scanning Electron Microscopy (SEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), acid-base titration analysis. The catalytic activity of these materials was tested in the esterification of a waste from palm oil deodorization and the main results obtained (about 93.3% of conversion) indicated that these materials have potential to act as heterogeneous solid acid catalysts. The prepared materials exhibited satisfactory catalytic performance even after a very simple recycling process in three reuse cycles, without significant loss of their activities.
RESUMO
The distillate produced by deodorization of palm oil (DDPO) is a waste that corresponds to 4% of the product formed in this process. DDPO is 83% free of fatty acids (FFA), making it a good material for biodiesel production. In this paper, a catalyst prepared from a waste material, Amazon flint kaolin, was used for the esterification of DDPO with methanol. Leached metakaolin treated at 950°C and activated with 4M sulfuric acid (labeled as MF9S4) offered maximum esterification activity (92.8%) at 160°C with a DDPO:methanol molar ratio of 1:60 and a 4-h reaction time. The influences of reaction parameters, such as the molar ratio of the reactants, alcohol chain length, temperature, time and the presence of glycerides and unsaponifiable matter, have also been investigated. Based on the catalytic results, esterification of DDPO using MF9S4 can be a cheaper alternative for production of sustainable fuels.
Assuntos
Biocombustíveis , Odorantes , Óleos de Plantas/metabolismo , Eliminação de Resíduos , Catálise , Cinética , Óleo de Palmeira , TemperaturaRESUMO
Differential scanning calorimetry (DSC) and a Rancimat method apparatus were applied to evaluate the oxidative stability of buriti pulp oil (Mauritia flexuosa Mart), rubber seed oil (Hevea brasiliensis), and passion fruit oil (Passiflora edulis). The Rancimat measurements taken for the oxidative induction times were performed under isothermal conditions at 100°C and in an air atmosphere. The DSC technique involved the oxidation of oil samples in an oxygen-flow DSC cell. The DSC cell temperature was set at five different isothermal temperatures: 100, 110, 120, 130 and 140°C. During the oxidation reaction, an increase in heat was observed as a sharp exothermic curve. The value T(0) represents the oxidative induction time, which is determined from the downward extrapolated DSC oxidative curve verses the time axis. These curves indicate a good correlation between the DSC T(0) and oxidative stability index (OSI) values. The DSC method is useful because it consumes less time and less sample.