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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...

Diesel fuel mixtures with high concentrations of biodiesel have been investigated to analyze the technical feasibility of their use in diesel cycle engines regarding thermal and oxidative properties. The results of combined techniques of oxidative stability, high Pressurized Differential Scanning Calorimetry (P-DSC), Calculated Cetane Index (CCI), and calorific power were used to verify the effect of the thermal-oxidative stability as a function of the percentage of biodiesel in the mixtures. The obtained results evidenced that the thermal and oxidative stability decreased with the addition of biodiesel from 50 to 5% v/v. Low stability fuels require rapid use as the oxidation compounds degrade the product and impair vehicle performance, as well as lead to corrosion and clogging problems in various mechanical systems.

Thermogravimetry was used in order to evaluate thermal and catalytic degradation of atmospheric residue of petroleum (ATR) which is found at Brazilian refineries, after a process of atmospheric distillation. The catalyst used for the thermocatalytic degradation of ATR was the AlMCM-41 mesoporous material. The AlMCM-41 was obtained from hydrothermal method using cetyltrimethylammonium as organic template. The calcined material was characterized by chemical analysis and X-ray diffraction. The thermogravimetry analysis was carried out at temperature range of 30 to 900 °C and heating rates of 5, 10 and 20 °C min−1, under nitrogen gas. From TG, the activation energy, determined using the Ozawa–Flynn–Wall kinetic method, decreased from 288 kJ mol−1, for pure ATR, to 55 kJ mol−1, in the presence of the AlMCM-41 material, evidencing the efficiency of the mesoporous materials for the catalytic degradation of petroleum residues.

The oil sludge residue presents an aggregate of hydrocarbons, organic and inorganic impurities, and water. The microporous and mesoporous zeolites are considered promising catalysts for processing of petroleum residues generated in refining processes. The aim of this work was to study the degradation of petroleum sludge obtained from primary processing, with applications of an improved thermogravimetry system and HY zeolite, at specific temperature ranges and degradation times, in order to obtain light gases and distillate fuels. The NaY zeolite was synthesized under hydrothermal treatment of a gel containing sodium silicate, sodium aluminate, and water. The obtained solid material was filtered, dried and calcined, and then ion-exchanged with ammonium chloride and calcined in order to obtain its protonic acid form (HY). The samples’ characterization by TG/DTG, XRD, and SEM proved that the crystalline structure of the faujasite zeolite was obtained. The thermal and catalytic degradation of the petroleum sludge was performed with 1.0 g of sample containing 10% of HY zeolite in the temperatures of 100, 200, 300, 400, and 500 °C, varying the time from 0 to 60 min to each temperature, using an oven with temperature program system, adapted with a Shimadzu precision balance. The curves obtained with this system evidenced that the presence of HY zeolite improves the degradation of the residue, with decreasing of the activation energy for the processes, as determined using the Arrhenius model.

Concretes were prepared containing oil sludge additive to produce new materials for construction. The oil sludge and concrete have previously been characterized in terms of chemical composition of the elements present in the materials. The concrete blocks were produced with a defined amount of oily sludge of 3.0 mass% on cement/water factor. All samples were cured at room temperature and then heated at 200 °C for 3 hours and 292 °C for 2h. The surfaces of the samples were subjected to previously grinding for the compressive strength testing. These tests were conducted in a press of 2000 kN load capacity. It was found that concrete containing additive showed a positive response in all the compressive strength tests, compared to concrete without the additive

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...

The hydrothermal synthesis of aluminophosphate molecular sieve type AlPO4-11 was processed from chemicals containing psueudobohemite, 85% phosphoric acid, water, and di-isopropylamine as templating agent. The crystallization of the samples was studied by taking samples in times from 2 to 74 h. The obtained white powder products were characterized by X-ray diffraction patterns (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG) and differential scanning calorimetry (DTG) data and pH measurement of the mother liquor. The pore volume, as determined from TG and DTG curves, was ca. 0.17 cm3g−1. The percent relative crystallinity was determined by XRD and FT-IR methods. The crystallization kinetics evidenced that the hydrothermal synthesis of AlPO4-11 exhibited in its initial phase a behavior of first order reaction with a specific velocity constant of ca. 0.25 h−1, as determined from XRD and FT-IR data. The results obtained by both X-ray diffraction and infrared spectroscopy are comparable, and FT-IR is found to be a rapid method for estimating crystallinity and structure of aluminophosphate.

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 the current work, the incorporation of niobium onto the nanostructured MCM-41 material was studied. The syntheses were carried out by the hydrothermal method using cetyltrimethylammonium bromide (CTMABr) as structural template, sodium silicate and water as solvent. Niobium was introduced in the reactive medium in the form of ammonium niobium oxalate, for obtaining Nb-MCM-41 materials. In order to verify the influence of the niobium content on the properties of the material, the samples were synthesized at Si/Nb molar ratios of 15, 30, 45 and 60. The materials were calcined and characterized by BET surface area, X-ray diffraction, Fourier transform infrared spectroscopy, X-rays fluorescence, for the determination of chemical composition, and scanning electron microscopy. The acidity properties of the MCM-41 and Nb-MCM-41, as determined by n-butylamine adsorption, were investigated by thermogravimetry in the temperature range of room temperature up to 600 °C, under nitrogen gas. From TG/DTG data, the acidity values were of 3.1–3.3 mmol g−1, for materials with Si/Nb molar ratio of 60, 45 and 30. The lower value of acidity of 0.6 mmol g−1, observed for Si/Nb = 15, suggests that at this molar ratio, Nb is not incorporated in the MCM-41 structure.

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 catalytic degradation of high density polyethylene (HDPE) was studied in the presence of HZSM-12 zeolites with different Si/Al ratio, by thermogravimetry and pyrolysis coupled to gas chromatography and mass spectrometry. The NaZSM-12 zeolite was synthesized by the hydrothermal method using methyltriethylammonium chloride as template. The HZSM-5 was obtained by ion exchange of NaZSM-12 with ammonium chloride, drying and subsequent calcination. The materials characterization were carried out by chemical analysis, X-ray diffraction, scanning electron microscopy, BET measurements and acidity by n-butylamine adsorption. The obtained HZSM-12 zeolites were physically mixed with HDPE in the proportion of 50%wt and submitted to thermogravimetric analyses at heating rates of 2.5; 5; 10 and 20 °C min −1 . The addition of HZSM-12 to HDPE produced a decreasing in the temperature of polymer degradation, which was proportional to the zeolite acidity. The activation energy (Ea) for the process was determined from the non-isothermal model-free kinetic model proposed by Vyazovkin. The Ea decreases linearly with the concentration of acid sites on the HZSM-12 materials. From the pyrolysis data, the obtained products were typically light gases (C 2 -C 3 ); liquid petroleum gases (C 4 -C 5 ); and gasoline (C 6 -C 10 ). This results suggest that acid zeolites are excellent materials for obtaining alternative fuels from catalytic recycling of plastics.

The presence of sulfur in diesel causes environmental pollution and corrosion of engines. In order to minimize the consequences of this pollutant, Brazilian laws established the maximum of sulfur content that diesel fuel may contain. To meet these requirements, diesel with a maximum sulfur concentration equal to 10 mg kg−1 (diesel S10) has been widely marketed in the country. The reduction in sulfur leads to changes in the physicochemical properties of the fuel, which are essential for the performance of road vehicles. This work aims to evaluate the reduction in the sulfur content in diesel fuel using thermogravimetry. Samples of diesel types S10, S500 and S1800, corresponding to 10, 500 and 1800 mg kg−1 of sulfur content, respectively, were tested according to ASTM methods for specific gravity, flash point and sulfur content. Then, these fuels were characterized by thermogravimetry from room temperature up to 500 °C, in helium flow, at heating rates of 5, 10 and 20 °C min−1. TG and DTG data showed a typical mass loss at ca. 40–320 °C, due to volatilization or distillation of light and medium hydrocarbons. Based on these data, the kinetic behavior of the samples was analyzed and the activation energies (E a) for decomposition of the samples decreased in the order: S1800 > S500 > S10.

Mg/Al layered double hydroxides (LDH) containing KI were synthesized and tested as basic heterogeneous catalysts for transesterification of sunflower oil, in order to obtain biodiesel. The process was carried out using reflux with 15:1 molar ratio of methanol to sunflower oil, and catalyst concentration of 2 mass%. The characterization of sunflower oil and biodiesel was accomplished according to ASTM and EN standard methods. The gas chromatographic and TG/DTG profiles were evaluated, and the results of yield and conversions were compared. The gas chromatographic analysis showed that the catalysts were effective in converting vegetable oil into biodiesel, specially using LDH catalysts modified with KI and molar ratio Mg/Al = 1, with conversions higher than 99 % indicating the strong influence of the chemical composition and controlled basicity, due to the presence of potassium in the structure of the catalyst.

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 adsorption of carbon dioxide on amino silanes-functionalized MCM-41 and SBA-15 materials is reported. The functionalization of mesoporous silicas was made by post-synthesis method, by impregnation of 3-aminopropyltriethoxysilane. The obtained materials were characterized by X-ray diffraction, scanning and transmission electron microscopies, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy measurements. The carbon dioxide adsorption capacities for the samples were carried out under ambient pressures. The obtained results evidenced that amino-silanes with a terminal amine (–NH2) were functionalized through covalent coupling of this group on the surface of the channels in the ordered mesoporous silica, meaning that the amine is anchored on the surface of the bigger pores of the MCM-41 and SBA-15 support. For functionalized materials, the CO2 adsorption capacity of the AMCM-41 increased from 0.18 to 1.1 mmol·g−1, whereas for ASBA-15, it was from 0.6 to 1.8 mmol·g−1. The Lagergren kinetic algorithms were applied in order to validate the obtained results, evidencing the enhanced carbon dioxide adsorption capacity and stability of the functionalized ordered mesoporous molecular sieves.

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.

This study aimed to evaluate the activity of Al-MCM-41, as mesoporous heterogeneous catalyst, for the thermal and catalytic degradation of a Brazilian heavy crude oil (14°API), via thermogravimetry. The American Petroleum Institute gravity (°API) is a measure of how light of heavy petroleum is when compared to water. The API value is an inverse measure of the relative density of a petroleum liquid, and it is used to compare the relative densities of petroleum samples. The catalytic activity was investigated as a function of different concentration of Al-MCM-41 (1, 3, 5, 10 and 20 mass%) added to the oil, as well as the apparent activation energy relative to degradation process. The TG runs were carried out at temperature range of 30–900 °C, at heating rates of 5, 10 and 20 °C min−1, under nitrogen atmosphere. From TG/DTG tests, the material presented effective catalytic activity when added to the heavy oil at concentration higher than 5 mass%. This property was clearly evidenced by the activation energy values. By the application of Ozawa–Flynn–Wall kinetic model, it was observed that when the amount of catalyst was increased, the value of the apparent activation energy decreased from 103 kJ mol−1 (without catalyst) to 70 kJ mol−1 (with 20 mass% of catalyst).

The mesoporous material AlSBA-15 with Si/Al molar ratio of 25 was synthesized by the hydrothermal method and characterized by X-ray diffraction and nitrogen adsorption. This is a promising material in the field of catalysis, particularly for petroleum refining, since their mesopores facilitate the accessibility of large hydrocarbon molecules to the active sites of AlSBA-15, producing light hydrocarbons. In order to evaluating the catalytic activity of AlSBA-15, a sample of ca. 10 % in mass of this solid was physically mixed with atmospheric residue of petroleum (ATR) and heated in a thermobalance from room temperature up to 900 °C, under nitrogen atmosphere. From TG curves, it was observed a reduction in the onset temperature, when AlSBA-15 was used as catalyst for the degradation process of ATR. The kinetic model proposed by Ozawa–Flynn–Wall yielded some kinetic parameters to determine the apparent activation energy of the degradation, evidencing the efficiency of the mesoporous material, since there was a decrease in the activation energy for the catalytic degradation. The ATR alone and mixed with AlSBA-15 was also heated in a pyrolysis reactor coupled to a gas chromatograph and mass spectrometer (Py-GC/MS). From the chromatograms, it was observed an increase in the yield of hydrocarbons in the range of gasoline and diesel derived from the catalytic process. These results are due to the combination of the mesoporosity and acidity of the AlSBA-15 for application in the process of pyrolysis of hydrocarbons molecules constituents of the ATR.

The pyrolysis of vacuum gasoil (VGO) was studied alone and in presence of HZSM-5/AlMCM-41 hybrid catalyst. This micro–mesoporous material was synthesized by the hydrothermal method using dual templates of tetrapropilamonium and cetyltrimethylammonium ions at different crystallization times. The obtained materials were washed and calcined for remotion of the organic templates. The characterization by X-ray diffraction, nitrogen surface area by the BET method, scanning and transmission electron microscopies, evidenced that typical MFI structure was embedded into the bulk of the MCM-41 matrix, in order to obtain the hybrid micro–mesoporous phase. The protonic form of the material was obtained by ion exchange with ammonium chloride solution and subsequent thermal treatment. The total acidity, as determined by n -butylamine adsorption, was equivalent to 0.75 mmol g −1 , in the temperature range of 300–500 °C, corresponding to strong acid sites. For catalytic reaction, a physical mixture of 10% of catalyst/VGO was decomposed in a thermobalance at heating rates of 5; 10 and 20 °C min −1 , from 100 to 550 °C. From TG/DTG data, applying the model-free kinetics, it was observed that the activation energy for the pyrolysis of VGO alone was ca. 125 kJ mol −1 . For VGO physically mixed to both AlMCM-41 and HZSM-5, the value decreased to ca. 80–90 kJ mol −1 , whereas for the hybrid, the value was the lowest, ca. 65 kJ mol −1 , evidencing the efficiency of the combined effect of the acid sites, crystalline phase and microporosity of ZSM-5 zeolite with the accessibility of the mesoporous of the AlMCM-41 ordered material. For determination of the catalytic properties, the samples of VGO and catalyst/VGO were submitted to pyrolysis-GC–MS system at 500 °C using helium as gas carrier. The VGO alone suffers decomposition to a wide range of hydrocarbons, typically C 17 –C 41 , while in the presence of catalyst, light fraction of hydrocarbons, in the range of liquefied petroleum gas (C 3 –C 5 ), gasoline (C 6 –C 10 ) and diesel (C 11 –C 16 ) were obtained, evidencing that the HZSM-5/AlMCM-41 hybrid material is an effective catalyst for pyrolysis of VGO.

In this work, a catalyst based on alumina impregnated with potassium iodide was synthesized and tested in the process of transesterification of rice bran oil with methanol. The reaction took place in a reflux system, with a molar ratio of 15:1 methanol:oil. The catalyst was prepared by impregnation of alumina with a solution of KI followed by calcination at 773 K for 3 h. The effect of concentration of the catalyst in the yield was verified in the range of 1–5 wt.%, and the properties of specific gravity and kinematic viscosity of the biodiesel were determined. The increasing of the yield of the reaction was observed for high amount of catalyst. When 5 wt.% of the catalyst was used in the process, the best results was obtained, with 95.2% yield. As expected, the specific gravity and kinematic viscosity decreased with the catalyst amount. From TG analysis, it was observed a mass loss of 96.2%, evidencing the high activity of the catalyst for the process.

Thermogravimetry was applied in order to investigate the catalytic degradation of heavy oil (15.4oAPI) over silica-based MCM-41 mesoporous molecular sieve. This material was synthesised by the hydrothermal method, using cetyltrimethylammonium bromide as organic template. The physicochemical characterization by nitrogen adsorption, X-ray diffraction, and thermogravimetry, showed that the obtained material presents well-defined structure, with a uniform hexagonal arrangement. The thermal and catalytic degradation of heavy oil was performed by thermogravimetric measurements, in the temperature range from 30 to 900 °C, at heating rates of 5, 10, and 20 °C min−1. By using the model-free kinetics, proposed by Vyazovkin, it was determined that the activation energy to degrade the heavy oil was ca. 128 kJ mol−1, and for degradation of oil in presence of MCM-41, this value decreased to 69 kJ mol−1, indicating the performance of the mesoporores catalyst for the degradation process.