Kleberson Ricardo de Oliveira Pereira

Hidrólise de celulose por catalisadores mesoestruturados NiO-MCM-41 e MoO3-MCM-41

This study was carried out to synthesize, characterize and evaluate the application of mesoestruturated catalysts MCM-41, 5%MoO3-MCM-41 and 5%NiO-MCM-41 in the hydrolysis of microcrystalline cellulose. XRD results indicate that the phase of mesoporous MCM-41 was obtained and that the introduction of metal oxides did not affect this mesoporous phase. About the heterogeneous hydrolysis reaction, it was observed that the increase in temperature results in a higher concentration of glucose and the catalyst 5%MoO3-MCM-41 provides the highest concentrations of glucose.

Evaluation of the Processing Conditions in the Transesterification for Biodiesel Production Using the Nanomagnetic Catalyst Ni0.5Zn0.5Fe2O4

Magnetic catalysts are easily removed from the reaction process, thereby reducing the wastewater generation. Therefore, the study proposes to evaluate the performance of the nanomagnetic catalyst Ni0.5Zn0.5Fe2O4 in the transesterification reaction of the soybean oil to produce biodiesel, varying processing conditions (temperature, molar ratio of oil:alcohol and catalyst amount) on the catalytic reaction. The catalyst was synthesized by combustion reaction and characterized by XRD, BET, magnetic measurements and gas chromatography. The results revealed the inverse spinel phase formation, type B(AB)2O4, with isotherm profile classified as type V with hysteresis loop of type 3 (H3), and surface area of 48.39 m2g-1. The magnetic hysteresis curve showed a characteristic behavior of soft magnetic material with saturation magnetization value of 55 emu/g. Chromatographic analysis confirmed that the magnetic nanoparticles are catalytically active and that the processing conditions directly influence the conversion into esters.

Synthesis of the Magnetic Nanoferrites of Spinel Type and Use in Esterification Reaction for Biodiesel Obtaining

Nanotechnology has been important in improving of the properties of the materials used in the manufacture of magnetic devices, electromagnetic radiation absorbers, cell telephony, pigments and lately in catalysis in transesterification and esterification reactions to biodiesel obtaining. The objective of this work was to synthesize and characterize magnetic materials of spinel type compound of CuFe2O4, CoFe2O4, MnFe2O4, NiFe2O4 and FeFe2O4 and to check the catalytic effect on the methyl esterification reaction of soybean oil. The samples were obtained by combustion reaction and characterized by XRD, FTIR, BET and SEM. The results analysis revealed for nanoferrites the spinel phase formation and higher specific area to the sample CoFe2O4. Generally the samples presented in irregular agglomerates form. All samples were catalytically active in the esterification reaction, with the highest conversion obtained by the sample MnFe2O4 with 57%.

Characterization of a Brazilian Bentonite for Its Use in the Oil and Gas Industry

Bentonites are an important kind of industrial clays with more than a hundred different uses. In the oil and gas industries they are used as thixotropic additives for drilling fluids and also as sorbents for purification of flows and effluents. Due to the mechanical and thermal properties that they exhibit, bentonites will become in a near future important fillers in clay/polymer nanocomposites which could be used in the oil and gas industry for replacement of various metal components. In this paper a chocolate color bentonite from the state of Paraiba in Brazil was characterized by diverse techniques such as XRD, DSC/TGA, surface area, and cation exchange capacity and it was studied its potential use as thixotropic additive for oil and gas drilling fluids and as sorbents of oils. The bentonite showed good potential for use in those applications.

Synthesis of Magnetic Nanoparticles Ni0.5Zn0.5Fe2O4 and Ni0.2Cu0.3Zn0.5Fe2O4 for Biodiesel Obtaining

The magnetic nanoparticles (MNPs) have chemical characteristics of acids or bases of Lewis or Brönsted and they allow their use in various processes, for example, in the biofuels synthesis. Thus, this study aimed to synthesize the MNPs of Ni0.5Zn0.5Fe2O4 and Ni0.2Cu0.3Zn0.5Fe2O4 to be used as catalysts in the transesterification reaction by methyl and ethyl route. In samples preparing we used the combustion reaction method and characterization by XRD, FTIR and BET. The catalytic reaction was conducted in a high pressure reactor on the conditions: 180°C for 1 hour, oil:alcohol molar ratio 1:12 and 2% of catalyst. The results indicate the formation of spinel inverted phase for the studied samples. In catalytic activity we observed an increase of 85% in conversion when we added Cu+2 to Ni0.5Zn0.5Fe2O4 system with conversion of 13.9% by methyl route and 10.8% by ethyl route.