Meiry Glaúcia Freire Rodrigues

Brazilian organoclays as nanostructured sorbents of petroleum-derived hydrocarbons

Organophilic clays were prepared using a bentonite from the town of Boa Vista, state of Paraiba, Brazil, and a quaternary ammonium salt (Genamin CTAC-50). The materials obtained were characterized by X-ray diffraction and infrared spectroscopy. The results showed a good gasoline, toluene, diesel fuel and kerosene adsorbing capacity.

Ruthenium promotion of Co/SBA-15 catalysts for Fischer-Tropsch synthesis in slurry-phase reactors

The aim of this work was to evaluate the catalytic properties of a Ru promoted Co/SBA-15 catalyst for Fischer-Tropsch synthesis (FTS). The Ru promoted Co/SBA-15 catalyst was prepared by wet impregnation method and was characterized by X-ray diffraction, X-ray energy dispersion spectrophotometer, N2 adsorption-desorption, temperature-programmed reduction and transmission electron microscopy. The Fischer-Tropsch synthesis using the catalyst was carried out to evaluate the catalyst activity and its effect on FTS product distribution. The synthesis was carried out in a slurry reactor operating at 513 K, 20 atm, CO: H2 molar ratio of 1: 1. X-ray diffraction showed that the calcined cobalt catalyst did not modify the structure of SBA-15, proving that Co was present in the form of Co3O4 in the catalyst. The addition of cobalt in SBA-15 decreased the specific superficial area of the molecular sieve. Fischer-Tropsch synthesis activity and C5+ hydrocarbon selectivity increased with the addition of Ru. The increases in activity and selectivity were attributed to the increased number of active sites resulting from higher reducibility and the synergetic effect of Ru and Co. Ru/Co/SBA-15 catalysts showed moderate conversion (40%) and high selectivity towards the production of C5+ (80 wt%).

Comparative Study of Organophilic Clays to be Used in the Gas & Petrol Industry

Brasgel clay and Gray clay has been been subjected to modification through ion-exchange reaction by quaternary ammonium (cetyltrimethyl ammonium bromide, CTAB). The samples were studied by X-Ray Diffraction, Infrared Spectroscopy, Scanning Electron Microscopy (SEM) and the Foster’s Swelling test. The results indicated that the quaternary ammonium salts were intercalated between the layers of clay. The basal spacing of unmodified Brasgel clay, determined by XRD, was 1.329 nm and after modification it increased up to 2.101 nm. By analyzing the results obtained in this study, particularly those provided by infrared spectroscopy, it was concluded that the treated, organophilic sample (modified with CTAB) comprised CH2 and CH3 groups in its structure, which provides evidence of the efficiency of the organophilization process. Foster´s swelling was carried out with and without agitation in gasoline, diesel, toluene and lubricating oil. The results indicated the samples was organophilic materials, with improved efficiency of Brasgel clay in gasoline and diesel and when compared to Gray clay in the test of capacity for adsorption and Foster´s swelling, the results were similar to kerosene and lubricating oil.

Obtenção e caracterização de materiais argilosos quimicamente ativados para utilização em catálise

The main objective of this paper is to characterize the chocolate smectite clays of Boa-Vista, PB, Brazil, in their natural form, and after chemical treatment, for their application in catalysis. The experimental methods were: X-ray fluorescence, X-ray diffraction and infrared spectroscopy. The results show that the acid treatment altered the montimorillonite structure. The obtained reaction (isomerization of m-xylene) for the treated material showed that treated clays were more active than the natural ones.

Synthesis of zeolite membrane (MCM-22/α-alumina) and its application in the process of oil-water separation

AbstractZeolite membrane (MCM-22/α-Al2O3) was prepared on α-Al2O3 disk by synthesis method (rubbing) and investigated through water separation and oily water recovery. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and mercury porosimetry. Thereafter, the separation of oil-water emulsion was evaluated. The crystallization behavior of the particles of the zeolite membrane is observed through the XRD. The images obtained by SEM of the zeolite membrane (MCM-22/α-Al2O3) showed that the method used for the synthesis of the zeolite membrane was effective since it showed the formation of a homogeneous surface with no cracks or defects on the surface of the porous support of α-Al2O3. Oil rejection was monitored. Fouling occurred as a layer on the membrane surface. The test showed that the MCM-22 zeolite membrane has potential for oil-water separation.

Evaluation of the acid properties of aluminossilicate MCM-22 material synthesized under static conditions

Abstract The hydrothermal synthesis of MCM-22 zeolite was carried out using silica, sodium aluminate and hexamethyleneimine, under static conditions at 150 °C for a period of 10 days, followed by washing with deionized water, drying overnight and calcination at 650 °C. The obtained material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD analysis evidenced that MCM-22 presented a well defined MWW structure. The FT-IR spectrum confirmed the efficiency of the hexamethyleneimine as an organic template used to direct the structure of the MCM-22 zeolite under static conditions. The SEM image indicated that the particles are spherical in shape, with a diameter of ca. 10 μm. The acid properties of the MCM-22 zeolite, as determined by n-buthylamine adsorption, were investigated in the temperature ranges of 105 to 300 °C and 300 to 525 °C, relative to medium and strong acid sites, respectively.

Performance of zeolite membrane (ZSM-5/γ-Alumina) in the oil/water separation process

AbstractThere are several technologies for the treatment of oily wastewater generated by the oil industry, not only to separate the emulsified oil in water, but also to reduce its concentration in the aqueous effluent. Among the processes of separation, the separation using membranes should be highlighted when they become an effective material and it also resistant to high temperatures, have good corrosion resistance, easy to clean, and have long life operation, among others. This work aims to synthesize the material (ZSM-5, γ-alumina membrane, and zeolite membrane ZSM-5/γ-alumina) and to evaluate the membranes in the oil/water separation in a continuous flow system. From the XRD results of the individual materials, it can be observed the formation of all the characteristic peaks for each material. The EDX analysis of zeolite ZSM-5 showed the formation of this material with a Si/Al = 19. From the SEM image of these materials, it can be seen that the surface of the γ-alumina is completely covered with ZSM-...

Swelling of Brazilian Organoclays in Some Solvents with Application in the Petroleum Industry

Brasgel clay has been modified via cation exchange reaction using quaternary ammonium chlorides (stearyl dimethylammonium chloride, Praepagen). Basal spacing, interlamellar structure clay have been characterized using X-ray diffraction (XRD) technique. The organoclay was characterized by the Foster Swelling test. The results indicated that the quaternary ammonium salts were intercalated between the layers of clay. The Foster Swelling Test results indicated that the affinity of stearyl dimethylammonium chloride, Praepagen occurred in the treated clay tested in all organic solvents (diesel, gasoline, toluene and p-xylene), without and with agitation. the treated sample presented a high swelling capacity (with and without agitation) when tested in gasoline. On the other hand, when inserted in diesel oil without agitation, the treated samples presented low swelling capacity, but when the assay was performed under agitation, it yielded an intermediate swelling capacity. In Toluene, the samples presented intermediate swelling, both without and with agitation. In p-xylene, the samples presented low swelling, without and intermediate swelling, with agitation. Therefore, this clay can be used for the removal of oils and greases from polluted aqueous effluents of the petroleum industry.

SBA-15 Molecular Sieve Using Clay as Silicon Sources

New sources of silica as a replacement for TEOS in the synthesis of SBA-15 are been performed by various research teams worldwide. The aim of this work is to describe the synthesis and characterization of SBA-15 made with chocolate B clay as an alternative source of silica by the hydrothermal method. Samples of classic SBA-15 were made with the traditional TEOS method. The samples of the two silica sources were characterized by DRX, EDX, and BET to evaluate the effects of the silica source on the synthesis of the molecular sieve. The chocolate B clay was efficient in the formation of the molecular sieve structure, but there was a great reduction in the surface area and total pore volume in comparison to the surface area of classic SBA-15.

Synthesis of MCM-22 Zeolite Membrane on a Porous Alumina Support

Much interest has been aroused in the application in industrial processes using zeolite membrane, due to its crystalline structure, and narrow pore diameters. These features enable the continuous separation of mixtures based on differences in molecular size and shape and also based on different adsorption properties. This paper reports the synthesis of MCM-22 zeolite membrane, using the method of secondary growth. The MCM-22 zeolite was synthesized by the hydrothermal method and characterized by spectroscopy Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM).The ceramic support (α-alumina) was prepared using the technique of forming powder and then subjected to the sintering temperature of 1400 °C/1h and characterized by XRD. The zeolite membrane preparation was performed by the method of secondary growth and characterized by XRD, SEM and mercury porosimetry. The obtained zeolite membrane could be confirmed by X-ray diffraction. From, the obtained SEM pictures it was possible to observe the formation of a homogeneous film on the zeolite surface of the ceramic support (α-alumina).