Preparação de óxidos mistos de níquel e zinco nanoparticulados a partir de combustíveis alternativos

The field of "Materials Chemistry" has been developing in recent years and there has been a great increase of interest in the synthesis and chemical and physical properties of new inorganic solids. New routes of synthesis and synthesis modified has been developed with the aim not only to optimize the processes in laboratory scale, but also on an industrial scale, and make them acceptable by current environmental legislation. The phenomenology of current solid state chemistry properties coupled with the high temperature superconductivity, ferromagnetism, porosity molecular and colors are evidence affected by the synthesis method, which in turn can influence the technological application of these materials. From this understanding, mixed oxides of nickel and zinc nanoparticulate were synthesized by microwave-assisted combustion route using three specific types of organic fuels employing the weight ratios 1:1/2 and 1:1 of cation metallic/fuel, in order to investigate the influence of such proportions to obtain the solids. The new fuels were chosen to replace, for example, urea or glycine that are the fuels most commonly preferred in this kind of synthesis. The powders without heat treatment were studied by Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD) and then calcined at 900°C. After heat treatment, the samples were characterized by analysis of X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The modified synthesis route porposed was effective for obtaining powders. Both the alternative fuels chosen as the different weight ratios employed, influenced in the morphology and obtaining oxides

Preparação de óxidos mistos de níquel e zinco nanoparticulados a partir de combustíveis alternativos

The field of "Materials Chemistry" has been developing in recent years and there has been a great increase of interest in the synthesis and chemical and physical properties of new inorganic solids. New routes of synthesis and synthesis modified has been developed with the aim not only to optimize the processes in laboratory scale, but also on an industrial scale, and make them acceptable by current environmental legislation. The phenomenology of current solid state chemistry properties coupled with the high temperature superconductivity, ferromagnetism, porosity molecular and colors are evidence affected by the synthesis method, which in turn can influence the technological application of these materials. From this understanding, mixed oxides of nickel and zinc nanoparticulate were synthesized by microwave-assisted combustion route using three specific types of organic fuels employing the weight ratios 1:1/2 and 1:1 of cation metallic/fuel, in order to investigate the influence of such proportions to obtain the solids. The new fuels were chosen to replace, for example, urea or glycine that are the fuels most commonly preferred in this kind of synthesis. The powders without heat treatment were studied by Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD) and then calcined at 900°C. After heat treatment, the samples were characterized by analysis of X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The modified synthesis route porposed was effective for obtaining powders. Both the alternative fuels chosen as the different weight ratios employed, influenced in the morphology and obtaining oxides

Estudo do processo de combustão in-situ em reservatórios maduros de óleos médios e leves (high pressure air injection)

Nearly 3 x 1011 m3 of medium and light oils will remain in reservoirs worldwide after conventional recovery methods have been exhausted and much of this volume would be recovered by Enhanced Oil Recovery (EOR) methods. The in-situ combustion (ISC) is an EOR method in which an oxygen-containing gas is injected into a reservoir where it reacts with the crude oil to create a high-temperature combustion front that is propagated through the reservoir. The High Pressure Air Injection (HPAI) method is a particular denomination of the air injection process applied in light oil reservoirs, for which the combustion reactions are dominant between 150 and 300°C and the generation of flue gas is the main factor to the oil displacement. A simulation model of a homogeneous reservoir was built to study, which was initially undergone to primary production, for 3 years, next by a waterflooding process for 21 more years. At this point, with the mature condition established into the reservoir, three variations of this model were selected, according to the recovery factors (RF) reached, for study the in-situ combustion (HPAI) technique. Next to this, a sensitivity analysis on the RF of characteristic operational parameters of the method was carried out: air injection rate per well, oxygen concentration into the injected gas, patterns of air injection and wells perforations configuration. This analysis, for 10 more years of production time, was performed with assistance of the central composite design. The reservoir behavior and the impacts of chemical reactions parameters and of reservoir particularities on the RF were also evaluated. An economic analysis and a study to maximize the RF of the process were also carried out. The simulation runs were performed in the simulator of thermal processes in reservoirs STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator) from CMG (Computer Modelling Group). The results showed the incremental RF were small and the net present value (NPV) is affected by high initial investments to compress the air. It was noticed that the adoption of high oxygen concentration into the injected gas and of the five spot pattern tends to improve the RF, and the wells perforations configuration has more influence with the increase of the oil thickness. Simulated cases relating to the reservoir particularities showed that smaller residual oil saturations to gas lead to greater RF and the presence of heterogeneities results in important variations on the RF and on the production curves

Estudo do processo de combustão in-situ em reservatórios maduros de óleos médios e leves (high pressure air injection)

Nearly 3 x 1011 m3 of medium and light oils will remain in reservoirs worldwide after conventional recovery methods have been exhausted and much of this volume would be recovered by Enhanced Oil Recovery (EOR) methods. The in-situ combustion (ISC) is an EOR method in which an oxygen-containing gas is injected into a reservoir where it reacts with the crude oil to create a high-temperature combustion front that is propagated through the reservoir. The High Pressure Air Injection (HPAI) method is a particular denomination of the air injection process applied in light oil reservoirs, for which the combustion reactions are dominant between 150 and 300°C and the generation of flue gas is the main factor to the oil displacement. A simulation model of a homogeneous reservoir was built to study, which was initially undergone to primary production, for 3 years, next by a waterflooding process for 21 more years. At this point, with the mature condition established into the reservoir, three variations of this model were selected, according to the recovery factors (RF) reached, for study the in-situ combustion (HPAI) technique. Next to this, a sensitivity analysis on the RF of characteristic operational parameters of the method was carried out: air injection rate per well, oxygen concentration into the injected gas, patterns of air injection and wells perforations configuration. This analysis, for 10 more years of production time, was performed with assistance of the central composite design. The reservoir behavior and the impacts of chemical reactions parameters and of reservoir particularities on the RF were also evaluated. An economic analysis and a study to maximize the RF of the process were also carried out. The simulation runs were performed in the simulator of thermal processes in reservoirs STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator) from CMG (Computer Modelling Group). The results showed the incremental RF were small and the net present value (NPV) is affected by high initial investments to compress the air. It was noticed that the adoption of high oxygen concentration into the injected gas and of the five spot pattern tends to improve the RF, and the wells perforations configuration has more influence with the increase of the oil thickness. Simulated cases relating to the reservoir particularities showed that smaller residual oil saturations to gas lead to greater RF and the presence of heterogeneities results in important variations on the RF and on the production curves