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The preparation, characterization and application of materials based on montmorillonite natural clay containing aluminum polyhydroxocomplexes of Keggin type ions (Al13) as intercalating agent and h...

The catalytic cracking of isopropylbenzene was investigaded over hybrid ZSM-12/MCM-41 and HZSM-12/MCM-48 micro-mesoporous materials, in order to verify the effect of the acid site of the accessibil...

This work presents a study of the reactive distillation of atmospheric petroleum residue (ATR) containing 10% in mass of HY or HZSM-5 zeolites. The process aims the upgrade of ATR in order ...

In research for materials that can be applied in processing heavy oil (petroleum), this work proposes to synthesize mesoporous heterogeneous catalysts, type SBA-15, with the addition of cerium metal and aluminum. These catalysts were characterized by X-ray diffraction, scanning electron micrographs coupled to energy dispersive spectrometry, spectroscopy in the infrared region by Fourier transform, N2 adsorption and desorption and thermal analysis-thermogravimetry. Thermal tests were performed to evaluate the thermal and catalytic degradation process with a sample of heavy oil (°API = 14). Through the non-isothermal kinetic model of Ozawa Flynn Wall (OFW) some parameters for determining the apparent activation energy of decomposition were obtained. The petroleum with 12% of Ce5Al50SBA-15 showed a catalytic activity for this material. It has been seen that there was a decrease in the Ea in model free of the order from 89.0 to 104.9 kJ mol−1 in α = 50% ± 10%, and it was repeated from the first percen...

The co-processing of petroleum and polyethylene terephthalate (PET) was carried out in the presence and absence of a catalyst in an open vessel batch reactor at temperatures of 200, 300, 400, and 500 °C, which corresponds to temperatures of distillation and cracking. The catalyst used was the acidic HY zeolite, which is widely used in petroleum refining. The catalytic co-processing was carried out with the PET–oil charge, at a mass ratio of 1:1, containing 10% of HY zeolite. The conversion degree was measured by knowing the initial sample mass and amount of degraded material for each temperature and reaction time, using an improved gravimetric method consisting of a precision balance and an oven with a heating rate controller. The conversion values obtained were compared for petroleum and PET samples with and without the zeolite catalyst. At temperatures of 200 and 300 °C, the PET showed low conversions, about 5–10%. However, for the catalytic co-processing of PET–oil/HY at these same temperatures...

The AlSBA-15 nanomaterials with different Si/Al ratios were investigated as a promising material for processing of atmospheric residue of petroleum (ATR). The processing was performed in a thermobalance using nitrogen as a carrier gas at different heating hates. The catalytic pyrolysis was performed with ATR sample containing 20% mass of AlSBA-15. Based on TG data by applying Ozawa-Flynn-Wall kinetic model, the activation energy for the pyrolysis of ATR was higher than for the ATR/AlSBA-15, throughout all range of decomposition, indicating that the nanostructured material is a promising material for processing petroleum residues in order to obtain liquid products in the gasoline and diesel range.

The zeolite HZSM-5, was synthesized in the absence of an organic template. The characterization of zeolite HZSM-5 was performed by X-ray diffraction, N2 adsorption/desorption isotherms and scanning electron microscopy. For catalytic tests, applying the free kinetic model, it was observed that the activation energy for the pyrolysis of pure VGO was of 82 kJ mol−1 and for VGO/HZSM-5, the value decreased to approximately 60 kJ mol−1, demonstrating the effectiveness of the acid sites effect of zeolite ZSM-5 for the VGO pyrolysis resulting in production of gas, gasoline and diesel.

Catry, P., Araujo, A., Cruz, C., Pinheiro, A., Pocas, M., Nadum, J., Armelin, M.& Pereira, J.R. 1999. Are mist-nets suitable for rapid habitat evaluations in the tropics? Results from a study in Guyinea-Bissau. Ostrich 70(2) 134–137 There is an increasing need for rapid habitat evaluations, in the tropics, for conservation purposes. Biodiversity is often assessed by studying relatively well known groups, such as birds. But even birds can be difficult to watch and identify in tropical habitats. Mist-netting is relatively free of observer bias, and allows sampling effort to be standardised. We sampled birds by mist-netting in seven wooded habitats, covering a wide range of levels of anthropogenic disturbance, in the Cufada region, Guinea Bissau. Capture rates, species diversity (as estimated by rarefaction) and originality of the bird communities appeared to be higher in disturbed habitats. Primary forest had the lowest capture rate and the lowest diversity index. Originality was also very low in primary fo...